You searched for subject:(dust).
Showing records 1 – 30 of
1249 total matches.
◁ [1] [2] [3] [4] [5] … [42] ▶
Baylor University
1.
Ma, Qianyu.
Charging of aggregate grains in astrophysical environments.
Degree: PhD, Physics., 2011, Baylor University
URL: http://hdl.handle.net/2104/8271 
► Plasma is a gas in which a portion of particles are ionized. Dust is a ubiquitous component of the universe, and when present in plasma,…
(more)
▼ Plasma is a gas in which a portion of particles are ionized.
Dust is a ubiquitous component of the universe, and when present in plasma, can form dusty plasma system.
Dust in the plasma is generally charged due to the constant collisions with free moving electrons and ions. Cosmic
dust can also be charged by other means such as UV and X-ray radiation, and secondary electron emission due to the impact of energetic electrons and ions. The presence of charged
dust particles alters the properties of the plasma. The charge on
dust grains also affects their dynamics, and influences the coagulation rate. Most previous work assumes that cosmic
dust is spherical in shape. However, remote observations and in-situ measurements indicate that cosmic
dust is likely to have an aggregate structure. This study examines the charging of aggregate grains in different astrophysical environments. A 3D numerical model employing a self-consistent iterative approach to compute the aggregate charge is introduced. Different size distributions for cosmic
dust grains are used in the simulation. The results are compared with previous work on spherical grains, and it is shown that the charging of aggregates differ significantly from that of spheres. Models on predicting charge based on the aggregate structure are proposed, and implications and consequences for future research are discussed.
Advisors/Committee Members: Matthews, Lorin Swint. (advisor).
Subjects/Keywords: Aggregates.; Dust charging.; Cosmic dust.
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ma, Q. (2011). Charging of aggregate grains in astrophysical environments. (Doctoral Dissertation). Baylor University. Retrieved from http://hdl.handle.net/2104/8271
Chicago Manual of Style (16th Edition):
Ma, Qianyu. “Charging of aggregate grains in astrophysical environments.” 2011. Doctoral Dissertation, Baylor University. Accessed March 06, 2021.
http://hdl.handle.net/2104/8271.
MLA Handbook (7th Edition):
Ma, Qianyu. “Charging of aggregate grains in astrophysical environments.” 2011. Web. 06 Mar 2021.
Vancouver:
Ma Q. Charging of aggregate grains in astrophysical environments. [Internet] [Doctoral dissertation]. Baylor University; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2104/8271.
Council of Science Editors:
Ma Q. Charging of aggregate grains in astrophysical environments. [Doctoral Dissertation]. Baylor University; 2011. Available from: http://hdl.handle.net/2104/8271
Texas A&M University
2.
Kazmi, Mohammad Zeeshan.
Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics.
Degree: MS, Safety Engineering, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/173398
► Polyethylene and sulfur are widely used substances in today’s industries, and therefore, the assessment and control of dust explosion risks associated with their production, storage,…
(more)
▼ Polyethylene and sulfur are widely used substances in today’s industries, and therefore, the assessment and control of
dust explosion risks associated with their production, storage, and usage are of paramount importance to ensure the safety standards in these industries. Since the petrochemical industry in Qatar is growing vastly to accommodate the Qatar National Vision for 2030, process industries in Qatar face challenges to control the hazards and risks of an explosion of both polyethylene and sulfur dusts which are generated in the polyolefin production process and in the desulfurization units of the gas processing plants, respectively.
Prevention of polyethylene and sulfur
dust explosions and the mitigation of their consequences require a deep understanding of the explosive properties of these dusts. This knowledge can be used to reduce the frequency of
dust explosions and to minimize the severity of explosions, therefore controlling the risks associated with polyethylene and sulfur
dust explosions. Very few data exist in literature regarding
dust explosibility properties for high density polyethylene (HDPE)
dust and sulfur
dust explosions. This experimental work focused on the determination of one of these explosive properties, called the minimum explosion concentration (MEC), for both polyethylene and sulfur
dust in the context of the Qatar industry.
To achieve the objectives of this research, the work was divided into three key phases:
• Phase I: Analysis of physical characteristics of both polyethylene and sulfur
dust found in local industries.
• Phase II: Experimental determination of MEC values for these dusts using a modified Hartmann tube and a 20-liter sphere.
• Phase III: Determine correlational relationship between
dust particle size and MEC of both polyethylene and sulfur
dust.
Results of this work gave insights regarding the explosibility of
dust samples used in local plants at Qatar. This research generates some new MEC data for both HDPE and sulfur
dust using a modified Hartmann tube. It was shown for both sulfur and polyethylene
dust, that at smaller particle sizes (<100 µm), the particle size does not have a strong influence on MEC values. For larger particle sizes, MEC will clearly increase with particle size.
Advisors/Committee Members: Vechot, Luc N (advisor), Mannan, M. Sam (advisor), Nounou, Hazem (committee member).
Subjects/Keywords: Dust Explosions
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kazmi, M. Z. (2018). Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173398
Chicago Manual of Style (16th Edition):
Kazmi, Mohammad Zeeshan. “Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics.” 2018. Masters Thesis, Texas A&M University. Accessed March 06, 2021.
http://hdl.handle.net/1969.1/173398.
MLA Handbook (7th Edition):
Kazmi, Mohammad Zeeshan. “Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics.” 2018. Web. 06 Mar 2021.
Vancouver:
Kazmi MZ. Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1969.1/173398.
Council of Science Editors:
Kazmi MZ. Experimental Study of Polyethylene and Sulfur Dust Explosion Characteristics. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173398
Brigham Young University
3.
Goodman, Michael Max.
Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources.
Degree: MS, 2019, Brigham Young University
URL: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9256&context=etd
► Dust originating from dry lakes contributes harmful and toxic elements to downwind urban areas and mountain snowpack that is compounded by local contaminant inputs from…
(more)
▼ Dust originating from dry lakes contributes harmful and toxic elements to downwind urban areas and mountain snowpack that is compounded by local contaminant inputs from anthropogenic sources. To evaluate dust contributions to an urban area from regional playas, we sampled playa dust sources, urban dust deposition, and snow dust deposition in central Utah, USA. Samples were analyzed for grain size, mineralogy, and chemistry. Bulk mineralogy between playa, urban, and snow dust samples was similar, with silicate, carbonate, and evaporite minerals. Grain size distribution between fine playa, urban, and snow dust particles was also similar. Elements found at high concentrations in playas include Li, Na, Mg, Ca, Sr, and U, and most other elements were found at higher concentrations in urban and snow deposition samples. Particularly enriched elements in dust deposition include Cu, Se, Ag, Cd, Sb, and La, which are sourced from industrial activity, mining, and vehicular emissions and wear. Based on results from mass balance modeling, a large majority of the dust mass deposited on the Wasatch Front is from playa sources. Urban and playa dust sources largely remain constant seasonally, although spikes in playa-associated element concentrations during a particular seasonal sample may indicate frequent and/or more intense dust events. Among the highly environmentally available elements B, Ca, Sr, and U, are Cd and Se, both of which present toxicity concerns for humans and environments. This is the first study describing heavy metal contamination and sources in Utah, USA.
Subjects/Keywords: playa dust; mineral dust; urban dust; dust chemistry
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Goodman, M. M. (2019). Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources. (Masters Thesis). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9256&context=etd
Chicago Manual of Style (16th Edition):
Goodman, Michael Max. “Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources.” 2019. Masters Thesis, Brigham Young University. Accessed March 06, 2021.
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9256&context=etd.
MLA Handbook (7th Edition):
Goodman, Michael Max. “Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources.” 2019. Web. 06 Mar 2021.
Vancouver:
Goodman MM. Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources. [Internet] [Masters thesis]. Brigham Young University; 2019. [cited 2021 Mar 06].
Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9256&context=etd.
Council of Science Editors:
Goodman MM. Wasatch Front Atmospheric Deposition Reflects Regional Desert Dust and Local Anthropogenic Sources. [Masters Thesis]. Brigham Young University; 2019. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9256&context=etd
McGill University
4.
Landry, Champlain.
The Effect of the Dust Particle Size on Dust Explosions.
Degree: M. Eng., Department of Mechanical Engineering, 1994, McGill University
URL: https://escholarship.mcgill.ca/downloads/c534fr23p.pdf
;
https://escholarship.mcgill.ca/concern/theses/7p88cj941
► L'étude de la combustion de particules est d'une importance fondamentale dans la détermination des paramètres d'explosion d'une suspension de particules. Les chercheurs ont étudié l'effet…
(more)
▼ L'étude de la combustion de particules est d'une importance fondamentale dans la détermination des paramètres d'explosion d'une suspension de particules. Les chercheurs ont étudié l'effet qu'avaient lesparamètres tels que la concentration de poussière, l'énergie d'allumage, etc., sur la combustion de poussière. Mais l'étude de l'influence de la dimension des particules n'a pas été faite de façon systématique. En particulier, les chercheurs ne distinguent pas entre l'incapacité de créer une suspension et la diminution de rythme d'augmentation de pression associe avec des dimensions de particule plus grande. […]
The study of dust combustion is of fundamental importance in determining the explosive characteristics of given dust suspensions. Researchers have studied how parameters such as concentration of dust, ignition energy, etc., influence dust combustion. However, the effect of the dust particle size has not been systematically investigated. In particular researchers do not distinguish between the inability of larger dust particle's to be dispersed and the slower burning rates associated with larger dust particles. […]
Advisors/Committee Members: Lee, John H. S. (Supervisor).
Subjects/Keywords: Dust
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Landry, C. (1994). The Effect of the Dust Particle Size on Dust Explosions. (Masters Thesis). McGill University. Retrieved from https://escholarship.mcgill.ca/downloads/c534fr23p.pdf ; https://escholarship.mcgill.ca/concern/theses/7p88cj941
Chicago Manual of Style (16th Edition):
Landry, Champlain. “The Effect of the Dust Particle Size on Dust Explosions.” 1994. Masters Thesis, McGill University. Accessed March 06, 2021.
https://escholarship.mcgill.ca/downloads/c534fr23p.pdf ; https://escholarship.mcgill.ca/concern/theses/7p88cj941.
MLA Handbook (7th Edition):
Landry, Champlain. “The Effect of the Dust Particle Size on Dust Explosions.” 1994. Web. 06 Mar 2021.
Vancouver:
Landry C. The Effect of the Dust Particle Size on Dust Explosions. [Internet] [Masters thesis]. McGill University; 1994. [cited 2021 Mar 06].
Available from: https://escholarship.mcgill.ca/downloads/c534fr23p.pdf ; https://escholarship.mcgill.ca/concern/theses/7p88cj941.
Council of Science Editors:
Landry C. The Effect of the Dust Particle Size on Dust Explosions. [Masters Thesis]. McGill University; 1994. Available from: https://escholarship.mcgill.ca/downloads/c534fr23p.pdf ; https://escholarship.mcgill.ca/concern/theses/7p88cj941
Louisiana State University
5.
Andrews, Jennifer Erin.
A comprehensive study of dust formation and evolution in core collape supernovae.
Degree: PhD, Physical Sciences and Mathematics, 2011, Louisiana State University
URL: etd-04182011-165249
;
https://digitalcommons.lsu.edu/gradschool_dissertations/2868
► Detection of large amounts of dust in high redshift galaxies suggests that core collapse supernovae (CCSNe) may play a critical role in the dust budget…
(more)
▼ Detection of large amounts of dust in high redshift galaxies suggests that core collapse supernovae (CCSNe) may play a critical role in the dust budget of galaxies in the early universe, when galaxies are only a few hundred million years old. At an age of only 1Gyr, asymptotic giant branch (AGB) stars may not have had the time to become significant dust contributors, leaving CCSNe as an alternative explanation since they quickly evolve and return their material to the surrounding interstellar medium. For the past three years, I have been observing the CCSNe 2007it and 2007od with Gemini, Hubble Space Telescope, and Spitzer Space Telescope in the optical and infrared to look for indicators of dust formation, which appear within the first few years after explosion. The data sets contain large temporal and wavelength coverage, and have led to some unusual and interesting results. In both cases there is evidence for interaction with surrounding circumstellar material (CSM), although neither was classified as a Type IIn. SN 2007it was found to be oxygen rich with a 56Ni mass quite large for a Type IIP, while SN 2007od is oxygen poor with a very low, over two orders of magnitude less, 56Ni mass. Scattered light echoes also seem to be present in both SNe. An estimated 10-4 solar masses of new dust has formed in each SN, consistent with other CCSNe, but still significantly less than needed to account for the amount of dust seen at high redshift. I will discuss these results and their implications for SNe as major dust contributors in the universe.
Subjects/Keywords: supernovae; dust
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Andrews, J. E. (2011). A comprehensive study of dust formation and evolution in core collape supernovae. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-04182011-165249 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2868
Chicago Manual of Style (16th Edition):
Andrews, Jennifer Erin. “A comprehensive study of dust formation and evolution in core collape supernovae.” 2011. Doctoral Dissertation, Louisiana State University. Accessed March 06, 2021.
etd-04182011-165249 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2868.
MLA Handbook (7th Edition):
Andrews, Jennifer Erin. “A comprehensive study of dust formation and evolution in core collape supernovae.” 2011. Web. 06 Mar 2021.
Vancouver:
Andrews JE. A comprehensive study of dust formation and evolution in core collape supernovae. [Internet] [Doctoral dissertation]. Louisiana State University; 2011. [cited 2021 Mar 06].
Available from: etd-04182011-165249 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2868.
Council of Science Editors:
Andrews JE. A comprehensive study of dust formation and evolution in core collape supernovae. [Doctoral Dissertation]. Louisiana State University; 2011. Available from: etd-04182011-165249 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2868
North-West University
6.
Grové, Tanya.
The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
Degree: 2009, North-West University
URL: http://hdl.handle.net/10394/6596
► Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts that contain crystalline…
(more)
▼ Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts that contain crystalline silica. Silica exposure is an occupational health priority even when exposure has ceased or is below the occupational exposure limit (0.1 mg/m3).
The objective of this study was to determine the individual contributions of the underground coal mining tasks to the total amount of respirable dust and respirable silica dust concentrations found in this environment. The tasks that were identified were continuous miner (CM) cutting, construction, the transfer point, tipping and roof bolting. Respirable dust sampling was conducted at the intake and return of each task, as well as at the intake and return of the section and the intake airway to the section. The five occupations that perform these tasks were also sampled to determine the personal exposure levels.
Respirable dust concentrations and small concentrations of respirable silica dust were found in the intake airway and intake of the section, indicating that the air that enters the section is already contaminated. The respirable dust-generating hierarchy of the individual tasks was: transfer point>CM right cutting> CM left cutting> CM face cutting> construction> roof bolting > tipping. For respirable silica dust the hierarchy was: CM left cutting> construction> transfer point> CM right cutting. CM face cutting, tipping and roof bolting generated concentrations of below quantifiable levels. The personal exposures also differed and the eM and stamler operators had the highest exposure to respirable dust (3.417 ± 0.862 mg/m3) and respirable silica dust (0.179 ± 0.388 mg/m3) concentrations, respectively. Recommendations have been included for lowering the respirable dust and silica dust concentrations that are generated and that the workers are exposed to underground.
Subjects/Keywords: Respirable dust;
Respirable silica dust;
Coal mining
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Grové, T. (2009). The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
(Thesis). North-West University. Retrieved from http://hdl.handle.net/10394/6596
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Grové, Tanya. “The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
” 2009. Thesis, North-West University. Accessed March 06, 2021.
http://hdl.handle.net/10394/6596.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Grové, Tanya. “The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
” 2009. Web. 06 Mar 2021.
Vancouver:
Grové T. The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
[Internet] [Thesis]. North-West University; 2009. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10394/6596.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Grové T. The evaluation and quantification of respirable coal and silica dust concentrations : a task-based approach / T. Grové.
[Thesis]. North-West University; 2009. Available from: http://hdl.handle.net/10394/6596
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Saskatchewan
7.
Nelson, Nathan.
Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma.
Degree: 2020, University of Saskatchewan
URL: http://hdl.handle.net/10388/13194
► Dust generation from Plasma Facing Components (PFC) is a problem for tokamaks as they approach suitable reactor conditions. Tungsten dust is especially detrimental in the…
(more)
▼ Dust generation from Plasma Facing Components (PFC) is a problem for tokamaks as they
approach suitable reactor conditions. Tungsten
dust is especially detrimental in the core,
due to associated high Z bremsstrahlung power losses. As Tungsten is a primary candidate
for PFC materials in large projects such as ITER, this remains a pressing issue. In order
to better understand
dust dynamics in tokamaks, a
dust injection experiment is proposed
for the Saskatchewan Torus-Modified (STOR-M). This experiment will utilize calibrated,
spherical tungsten micro-particles. A known mass of these tungsten micro-particles are
to be injected into STOR-M with control over the position of the
dust plume. This will
enable future observation and study of
dust dynamics within STOR-M.
In preparation for this experiment, a new
dust injector has been designed, based on the
fast gas valve for the University of Saskatchewan Compact Torus Injector. An experimental
test apparatus was developed to characterize the
dust injector. In the experiment, nitrogen
gas and
dust particles are injected into the test vacuum chamber under various
dust
injector parameters. Vacuum chamber pressures range from 10−4
- 10−5 Torr, which is
within the operation range of STOR-M. These particles are then imaged with a high-speed
camera via laser light scattering. Collected 12-bit raw image data was then processed and
analysed. This analysis fully characterizes the
dust injector in terms of the time evolution
of the injector
dust plume, amount of gas injected and injected
dust mass.
Advisors/Committee Members: Bradley, Michael, Degenstein, Doug, Zhang, Lifeng, Tse, John.
Subjects/Keywords: Dust Injector; Tokamak; Compact Torus; Tungsten Dust
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Nelson, N. (2020). Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/13194
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nelson, Nathan. “Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma.” 2020. Thesis, University of Saskatchewan. Accessed March 06, 2021.
http://hdl.handle.net/10388/13194.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nelson, Nathan. “Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma.” 2020. Web. 06 Mar 2021.
Vancouver:
Nelson N. Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma. [Internet] [Thesis]. University of Saskatchewan; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10388/13194.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nelson N. Design and Characterization of a Dust Injector for Future Studies of Tungsten Dust in the STOR-M Plasma. [Thesis]. University of Saskatchewan; 2020. Available from: http://hdl.handle.net/10388/13194
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
8.
Zhang, Wei.
A Study of Dust Movement through Construction Barriers.
Degree: MS, Construction Management, 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/153911
► Airborne infection agents can and do infect patients who have a lung disease or who are coping with a weakened immune systems or in some…
(more)
▼ Airborne infection agents can and do infect patients who have a lung disease or who are coping with a weakened immune systems or in some circumstances otherwise apparently healthy people. A rise in the rate of fungal infection for a particular class of immunosuppressed patients occurred in the last few decades as the medical system improved treatment and reduced mortality rates for a number of common and previously fatal medical conditions. Fungal infection agents are opportunistic and ubiquitous. Fungal infection agents potentially derive from three sources in a hospital setting, from the air handling system, from any construction activity and from the normal hospital operations. These sources were termed Source S-AH, Source S-CA and Source S-NO for this research work respectively. Source S-AH and S-NO are always present in the hospital setting, Source S-CA requires construction activity in or near the hospital. This research work studies the movement of
dust particles that can transport Aspergillus spore. Previous research demonstrated that a well-constructed barrier could stop the movement of
dust particles from a contaminated to a non-contaminated side. However, it is not practical to completely isolate construction activity in a hospital setting from a patient cohort; the practical step is to reduce the incidence of spore movement on
dust through openings in the construction barriers. This research studies the movement characteristics of
dust through an opening in a construction barrier in a test rig that models a construction site in a laboratory setting. The results demonstrate movement of the
dust occurs with the provision of an opening in a plastic construction wall. The filter collection system analysis showed that the distribution of the
dust did not follow a uniform pattern but showed concentrations in a few locations on the filter. The location on the filter directly beneath the door showed a five-fold total concentration when compared to an area beneath the recirculating fan inlet. The conclusion reached is the airflow direction coupled with random Brownian motion impacts on the concentration of
dust particles. The hypothesis is false. Future research should be directed at understanding the physical issues of the
dust movement in a room setting and developing a finite element model of the test arrangement.
Advisors/Committee Members: Nichols, John M. (advisor), Escamilla, Edelmiro (committee member), Glowacki, Kevin T. (committee member).
Subjects/Keywords: Aspergillu; dust movement
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, W. (2014). A Study of Dust Movement through Construction Barriers. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153911
Chicago Manual of Style (16th Edition):
Zhang, Wei. “A Study of Dust Movement through Construction Barriers.” 2014. Masters Thesis, Texas A&M University. Accessed March 06, 2021.
http://hdl.handle.net/1969.1/153911.
MLA Handbook (7th Edition):
Zhang, Wei. “A Study of Dust Movement through Construction Barriers.” 2014. Web. 06 Mar 2021.
Vancouver:
Zhang W. A Study of Dust Movement through Construction Barriers. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1969.1/153911.
Council of Science Editors:
Zhang W. A Study of Dust Movement through Construction Barriers. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153911
9.
Pedersen, Ralston.
Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument.
Degree: 2019, University of Nevada – Reno
URL: http://hdl.handle.net/11714/5768
► A real-time photoacoustic coal-dust monitor for underground mining applications has been developed to address the health and safety concerns associated with dust related illnesses. This…
(more)
▼ A real-time photoacoustic coal-
dust monitor for underground mining applications has been developed to address the health and safety concerns associated with
dust related illnesses. This instrument was co-developed with Patrick Arnott, Sarah Tesfasion and Apryl Witherspoon of the UNR Physics department. The primary goals addressed in development of this real-time coal-
dust monitor were user portability, instrument durability and maintaining a low development cost. Instrument functionality and principles for operation were based off older, large and free-standing photoacoustic
dust-monitors previously designed by Patrick Arnott. To scale down these instruments to a user portable size, the resonance chamber, pumps and controls were addressed. After prototype completion, the instrument was tested with Kerosene soot to determine efficacy and accuracy. Success from the kerosene test led to further testing against other
dust-monitoring instruments at NIOSH laboratories in Philadelphia by Arnott, Tesfasion and Witherspoon. The current instrument has proven very effective for determining organic aerosols such as coal-
dust; however, further development is planned to include a laser frequency that can more effectively accommodate silica
dust. Further reducing the size of the current instrument is a major goal for future development to achieve a truly user-portable
dust-monitor.
Advisors/Committee Members: Kocsis, Karoly (Charles) (advisor), Abbasi, Behrooz (committee member), Sattarvand, Javad (committee member), Nesbitt, Carl (committee member), Breitmeyer, Ronald (committee member).
Subjects/Keywords: Coal; Dust; Monitoring
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pedersen, R. (2019). Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument. (Thesis). University of Nevada – Reno. Retrieved from http://hdl.handle.net/11714/5768
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pedersen, Ralston. “Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument.” 2019. Thesis, University of Nevada – Reno. Accessed March 06, 2021.
http://hdl.handle.net/11714/5768.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pedersen, Ralston. “Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument.” 2019. Web. 06 Mar 2021.
Vancouver:
Pedersen R. Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument. [Internet] [Thesis]. University of Nevada – Reno; 2019. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11714/5768.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pedersen R. Development, Application and Validation of the Real-Time Coal Dust Monitoring Instrument. [Thesis]. University of Nevada – Reno; 2019. Available from: http://hdl.handle.net/11714/5768
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Colorado State University
10.
Duncan, Caroline R.
Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado.
Degree: MS(M.S.), Ecosystem Science and Sustainability, 2020, Colorado State University
URL: http://hdl.handle.net/10217/211991
► Deposited dust layers reduce the surface albedo of snow and accelerate melt by this change to the snowpack energy balance. Senator Beck Study Basin in…
(more)
▼ Deposited
dust layers reduce the surface albedo of snow and accelerate melt by this change to the snowpack energy balance. Senator Beck Study Basin in the San Juan Mountains of southwestern Colorado monitors the effects of
dust on midlatitude continental snowpack. Continuous automated measurements include shortwave and longwave radiation in addition to conventional micrometeorological variables.
Dust layer characteristics and snow properties are collected during snow pit excavation throughout each ablation period. Both sets of data were used to simulate snowpack under observed and
dust-free conditions with the snow energy balance model SNOBAL for WY2007 to WY2019. Across the 13 years,
dust concentrations ranged from 0.16 to 4.80 mg g-1 resulting in a range of daily mean
dust-enhanced absorbed visible energy from 31 to 50 W m-2 during ablation, with hourly peaks up to 347 W m-2. We found snow melt accelerated by 11 to 31 days in a logarithmic response to end-of-year
dust concentration modified by seasonal variations in snow amount and cloud cover.
Advisors/Committee Members: Fassnacht, Steven (advisor), Kampf, Stephanie (committee member), Ham, Jay (committee member).
Subjects/Keywords: melt; dust; snow
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Duncan, C. R. (2020). Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/211991
Chicago Manual of Style (16th Edition):
Duncan, Caroline R. “Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado.” 2020. Masters Thesis, Colorado State University. Accessed March 06, 2021.
http://hdl.handle.net/10217/211991.
MLA Handbook (7th Edition):
Duncan, Caroline R. “Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado.” 2020. Web. 06 Mar 2021.
Vancouver:
Duncan CR. Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado. [Internet] [Masters thesis]. Colorado State University; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10217/211991.
Council of Science Editors:
Duncan CR. Patterns of dust-enhanced absorbed energy and shifts in melt timing for snow of southwestern Colorado. [Masters Thesis]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/211991
Penn State University
11.
Akarslan, Gokhan.
EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL.
Degree: 2018, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/16041gza8
► Dust trail behind a moving vehicle is an undesirable situation for human health and military operations. However, very little is known about the dust emission…
(more)
▼ Dust trail behind a moving vehicle is an undesirable situation for human health and military operations. However, very little is known about the
dust emission and
dust deposition from moving vehicle. Thus, a better understanding is required to eliminate
dust dispersion. As an initial step, this work aims to study problem experimentally for scalable, simplified object, in this case, a cylinder. This experimental study was performed in a wind tunnel to observe how
dust emission and
dust deposition are related to Reynolds number and a gap between the wind tunnel bottom wall and cylinder. Experiments were repeated for various Reynolds numbers and the different gap to cylinder diameter ratios, while the Reynolds numbers which based on the cylinder diameter are in the range of 12655 to 29000, the gap to diameter ratios are between 0.1 and 0.5.
Advisors/Committee Members: Rui Ni, Thesis Advisor/Co-Advisor, Bo Cheng, Committee Member.
Subjects/Keywords: Dust Dispersion; Dust Emission; Two-Phase Flow; Dust Deposition
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Akarslan, G. (2018). EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/16041gza8
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Akarslan, Gokhan. “EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL.” 2018. Thesis, Penn State University. Accessed March 06, 2021.
https://submit-etda.libraries.psu.edu/catalog/16041gza8.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Akarslan, Gokhan. “EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL.” 2018. Web. 06 Mar 2021.
Vancouver:
Akarslan G. EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL. [Internet] [Thesis]. Penn State University; 2018. [cited 2021 Mar 06].
Available from: https://submit-etda.libraries.psu.edu/catalog/16041gza8.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Akarslan G. EXPERIMENTAL STUDY OF THE DUST TRAIL PHENOMENON IN A WIND TUNNEL. [Thesis]. Penn State University; 2018. Available from: https://submit-etda.libraries.psu.edu/catalog/16041gza8
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
NSYSU
12.
Lin, Zheng-Yhen.
Numerical simulation and analysis of dust emission in steelmaking plant.
Degree: Master, Institute Of Mechanical And Electro-Mechanical Engineering, 2018, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0619118-174147
► Steelmaking is a polluting industry, and its process will produce a lot of smoke containing exhaust gas and heavy metal dust particles. If it is…
(more)
▼ Steelmaking is a polluting industry, and its process will produce a lot of smoke containing exhaust gas and heavy metal
dust particles. If it is not properly handled, it will cause great harm to the environment. The most important recovery method is the
dust collection system. Most of the polluting gases and toxic
dust can be collected by a combination of
dust collection and secondary
dust collection. However, the
dust collection system design of some steelmaking plants is not perfect. How much
dust scattered outside the factory is one of the key tasks that need to be clarified.
This study focuses on the establishment of a geometric model of the 3D EAF building to simulate exhaust gas and
dust flow in the plant during the feeding and refining periods. In the study, a set of operating conditions will be fixed, and the effects of exhaust gas flow rate, secondary
dust collection flow rate, and exhaust gas initial temperature on the total exhaust gas emission rate will be discussed separately, and transient trajectory particles will be used to describe the trajectories of metal
dust particles.
The results show that the secondary
dust collection in the electric furnace plant is too far away from the furnace mouth. As the exhaust gas rises, it will mix with the cold air and cause the exhaust gas concentration to decrease, the
dust collection efficiency is not high.
In the case of feeding, the concentration of exhaust gas accumulated on the top of the plant will become higher, and the exhaust gas emission rate will be more than when the bucket is not poured. In addition, the
dust will accumulate in the
dust collecting hood. When the accumulation density is increased until the secondary
dust collection cannot be instantaneously taken away, it will begin to spread around. Diffused
dust will have a diameter particle size distribution in the factory due to different terminal speeds.
Dust particles larger than 40μm will settle first, and
dust particles smaller than 20μm will float on the top of the plant for the longest time. In operation condition, increasing the secondary
dust collecting air volume can effectively improve the
dust and exhaust gas emission.
Advisors/Committee Members: Sheng-Yen Hsu (committee member), Chien-Chou Tseng (chair), Chien-Hsiung Tsai (chair), Yung-Chang Liu (chair), Yu-lun Huang (chair).
Subjects/Keywords: numerical simulation; Dust collecting system; DPM; Dust escape; Electric arc furnace dust
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lin, Z. (2018). Numerical simulation and analysis of dust emission in steelmaking plant. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0619118-174147
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lin, Zheng-Yhen. “Numerical simulation and analysis of dust emission in steelmaking plant.” 2018. Thesis, NSYSU. Accessed March 06, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0619118-174147.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lin, Zheng-Yhen. “Numerical simulation and analysis of dust emission in steelmaking plant.” 2018. Web. 06 Mar 2021.
Vancouver:
Lin Z. Numerical simulation and analysis of dust emission in steelmaking plant. [Internet] [Thesis]. NSYSU; 2018. [cited 2021 Mar 06].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0619118-174147.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lin Z. Numerical simulation and analysis of dust emission in steelmaking plant. [Thesis]. NSYSU; 2018. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0619118-174147
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
13.
Roebroeks, E. (author).
ZPEC - The Zodiacal Dust Polarization Evaluation Code.
Degree: 2016, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:f45b0cc5-4d20-4617-b7d1-be8d280a5a92
► The habitability of exoplanets is determined by their surface properties and atmospheres, spectropolarimetry is a powerful tool to characterize these. Numerical models can be used…
(more)
▼ The habitability of exoplanets is determined by their surface properties and atmospheres, spectropolarimetry is a powerful tool to characterize these. Numerical models can be used to simulate the polarimetric signals of these exoplanets, but these computed signals have to be compared with observations. The best test-case for such a comparison is the Earth, as the atmospheric and surface properties are well-known and the signal can be computed to a high accuracy. The Lunar Observatory for Unresolved Polarimetry of Earth (LOUPE) shall take measurements of the unresolved Earth being based on the Moon. When observing exoplanets or the Earth, dust in planetary systems acts as a noise source and a source of confusion. This so-called zodiacal dust adds to the polarimetric signal of the planet and in some cases a dust clump might be confused with a planet. The aim of the thesis is to develop a computational tool that allows to analyze the zodiacal dust in order to estimate the noise level and to determine if dust clumps can be distinguished from exoplanets using their polarization signals. The developed computational tool is called ZPEC: the Zodiacal Dust Polarization Evaluation Code. It uses a Monte-Carlo based algorithm in order to track individual photon paths. When photons are scattered their polarization properties are calculated, which are verified using the Adding-Doubling code for flat layers. ZPEC allows to analyze how photon properties change when they are scattered multiple times by a dust particle, whereas classically it is assumed that zodiacal dust disks are optically thin enough to assume photons are scattered only once. The dust model of the COBE/DIRBE mission is used to model the dust in the Solar System, a NASA collisional model was used to model the dust disk surrounding star ? Pictoris. The ZPEC photon property databases are used to generate hypothetical detector views. Using ZPEC it is concluded that the Earth sometimes seems to disappear against the polarization signal of the background dust, while the maximum brightness of the dust to the Earth signal is 0.14%. It is also concluded for the dust disk orbiting ? Pic that ignoring multiple scattering leads to errors in the calculated polarization signal that are estimated to be 4-9% (relative). In addition it is concluded that dust clumps show the same polarization behavior as the surrounding dust, while planets do not. Hence using brightness only the two can be confused, but they can be distinguished based on their polarization behavior.
Astrodynamics & Space Missions
Spaceflight
Aerospace Engineering
Advisors/Committee Members: Stam, D.M. (mentor).
Subjects/Keywords: zodiacal dust; exozodiacal dust; exoplanets; polarimetry; dust disks; Beta Pictoris; multiple scattering
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Roebroeks, E. (. (2016). ZPEC - The Zodiacal Dust Polarization Evaluation Code. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:f45b0cc5-4d20-4617-b7d1-be8d280a5a92
Chicago Manual of Style (16th Edition):
Roebroeks, E (author). “ZPEC - The Zodiacal Dust Polarization Evaluation Code.” 2016. Masters Thesis, Delft University of Technology. Accessed March 06, 2021.
http://resolver.tudelft.nl/uuid:f45b0cc5-4d20-4617-b7d1-be8d280a5a92.
MLA Handbook (7th Edition):
Roebroeks, E (author). “ZPEC - The Zodiacal Dust Polarization Evaluation Code.” 2016. Web. 06 Mar 2021.
Vancouver:
Roebroeks E(. ZPEC - The Zodiacal Dust Polarization Evaluation Code. [Internet] [Masters thesis]. Delft University of Technology; 2016. [cited 2021 Mar 06].
Available from: http://resolver.tudelft.nl/uuid:f45b0cc5-4d20-4617-b7d1-be8d280a5a92.
Council of Science Editors:
Roebroeks E(. ZPEC - The Zodiacal Dust Polarization Evaluation Code. [Masters Thesis]. Delft University of Technology; 2016. Available from: http://resolver.tudelft.nl/uuid:f45b0cc5-4d20-4617-b7d1-be8d280a5a92
University of Pretoria
14.
[No author].
Computational fluid dynamics model for controlling dust
and methane in underground coalmines
.
Degree: 2011, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-09222011-125600/
► Airborne dust and methane are common problems in the underground coalmines. They pose health and safety risk to mining personnel, and a safety risk to…
(more)
▼ Airborne
dust and methane are common problems in the
underground coalmines. They pose health and safety risk to mining
personnel, and a safety risk to mining equipment as well. In order
to prevent these risks air borne
dust and methane concentrations
must be reduced to within the acceptable levels. In South Africa,
the
dust and methane concentration in coalmines should not exceed
2.0 mg/m³ and 0.5% per volume, respectively. Mine ventilation is
one of the popular ways of controlling both
dust and methane.
Different ventilation systems have been designed since the history
of underground coal mining. Unfortunately, none provides ultimate
solution to the
dust and methane problem, especially in the most
critical areas of the underground coalmine, like blind-end of the
heading and last through road. By changing airflow patterns and air
velocity, it is possible to obtain an optimum ventilation design
that can keep
dust and methane within the acceptable levels. Since
it is very difficult to conduct experiments in the underground
coalmine due to harsh environmental conditions and tight production
schedules, the designer made use of the Computational Fluid
Dynamics (CFD) modelling technique. The models were then
experimentally verified and validated using a scaled down model at
University of Pretoria. After verification further numerical
analysis was done to in order to device a method for determining
optimum fan positions for different heading dimensions. This study
proves that CFD can be used to model ventilation system of a scaled
down coalmine model. Therefore chances that this might be true for
the actual mine are very high but it needs to be investigated. If
this is found to be true then CFD modelling will be a very useful
tool in coalmine ventilation system research and
development.
Advisors/Committee Members: Dr J Dirker (advisor), Prof N D L Burger (advisor).
Subjects/Keywords: Fluid dynamics;
Dust;
Methane;
UCTD
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2011). Computational fluid dynamics model for controlling dust
and methane in underground coalmines
. (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-09222011-125600/
Chicago Manual of Style (16th Edition):
author], [No. “Computational fluid dynamics model for controlling dust
and methane in underground coalmines
.” 2011. Masters Thesis, University of Pretoria. Accessed March 06, 2021.
http://upetd.up.ac.za/thesis/available/etd-09222011-125600/.
MLA Handbook (7th Edition):
author], [No. “Computational fluid dynamics model for controlling dust
and methane in underground coalmines
.” 2011. Web. 06 Mar 2021.
Vancouver:
author] [. Computational fluid dynamics model for controlling dust
and methane in underground coalmines
. [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2021 Mar 06].
Available from: http://upetd.up.ac.za/thesis/available/etd-09222011-125600/.
Council of Science Editors:
author] [. Computational fluid dynamics model for controlling dust
and methane in underground coalmines
. [Masters Thesis]. University of Pretoria; 2011. Available from: http://upetd.up.ac.za/thesis/available/etd-09222011-125600/
Universiteit Utrecht
15.
Anthonisse, M.I.
The Effect of Ionization on the Air Quality in a Horse Stable.
Degree: 2014, Universiteit Utrecht
URL: http://dspace.library.uu.nl:8080/handle/1874/297097
► Horses kept in stables are likely to be exposed to high levels of organic dust. Organic dust plays a role in increased risk of inflammatory…
(more)
▼ Horses kept in stables are likely to be exposed to high levels of organic
dust. Organic
dust plays a role in increased risk of inflammatory reactions and is associated with respiratory diseases. There are multiple ways to decrease the amount of organic
dust in the horse stable, of which the most common are a change in bedding and feeding regime and an increase in natural ventilation. The aim of this study was to investigate the effect of the ionization of air on
dust, endotoxin and fungus in horse stables , and the differences between those levels in stables with horses kept on shavings eating haylage and stables with horses kept on straw eating dry hay.
Four units (96m2 each) of six boxes were used. Each unit was equipped with an ionization installation, composed of a ionizationbox connected to electricity network, 3 corona wires and 4 earthed wires (all wires had a length of 12m). In 2 units, horses were kept on shavings and were fed haylage and in the other 2 units horses were kept on straw and were fed dry hay. Ambient inhalable
dust samples were collected on a fixed, similar position within each unit. Samples were taken in each unit with and without activated ionization and during daytime and during nighttime, repeatedly over the course of a week. In addition, sampling was performed on 5 different positions in each stable unit to verify if there are locations within stable units that have consistent higher
dust levels than other locations. The
dust samples were analyzed for endotoxin by the Limulus Amebocyte Lysate assay. Culturable fungi were collected with an Anderson impactor on DG-18 Agar plates, with a sampling time of 30 seconds per sample.
156 samples were examined for
dust levels and 154 samples were examined for endotoxin levels. Highest
dust and endotoxins levels were found in the units where the horses were kept on straw, being fed dry hay. Comparing day and night, higher
dust and endotoxins levels were found during daytime. 86 samples were taken for the examination of growth of fungal colonies. Samples taken in straw units showed higher growth of fungal colonies than samples taken in units where horses were kept on shavings. Nighttime sampling showed less fungal growth than daytime sampling.
No difference in
dust, endotoxins or fungal growth were found when ionization was activated.
Dust, endotoxins and fungal spores do tend to be significantly lower in stables where horses are being kept on shavings, being fed with haylage, compared to stables where they are being kept on straw and being fed with hay.
Advisors/Committee Members: Westermann, C.M., van Eerdenburg, F.J.C.M., Wouters, I.M..
Subjects/Keywords: Ionization; dust; endotoxin; fungus
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Anthonisse, M. I. (2014). The Effect of Ionization on the Air Quality in a Horse Stable. (Masters Thesis). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/297097
Chicago Manual of Style (16th Edition):
Anthonisse, M I. “The Effect of Ionization on the Air Quality in a Horse Stable.” 2014. Masters Thesis, Universiteit Utrecht. Accessed March 06, 2021.
http://dspace.library.uu.nl:8080/handle/1874/297097.
MLA Handbook (7th Edition):
Anthonisse, M I. “The Effect of Ionization on the Air Quality in a Horse Stable.” 2014. Web. 06 Mar 2021.
Vancouver:
Anthonisse MI. The Effect of Ionization on the Air Quality in a Horse Stable. [Internet] [Masters thesis]. Universiteit Utrecht; 2014. [cited 2021 Mar 06].
Available from: http://dspace.library.uu.nl:8080/handle/1874/297097.
Council of Science Editors:
Anthonisse MI. The Effect of Ionization on the Air Quality in a Horse Stable. [Masters Thesis]. Universiteit Utrecht; 2014. Available from: http://dspace.library.uu.nl:8080/handle/1874/297097
San Jose State University
16.
Bruggeman, David.
Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT.
Degree: MS, Meteorology and Climate Science, 2015, San Jose State University
URL: https://doi.org/10.31979/etd.9kn2-vwb2
;
https://scholarworks.sjsu.edu/etd_theses/4625
► An analysis of the advection of air parcels in the Martian atmosphere during the 2001 global dust storm through the use of three-dimensional trajectories…
(more)
▼ An analysis of the advection of air parcels in the Martian atmosphere during the 2001 global dust storm through the use of three-dimensional trajectories is presented. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, well-known for trajectory, dispersion, and deposition modeling, and originally developed for Earth was modified for Mars to provide forward and backward trajectories. The custom HYSPLIT for Mars uses meteorological input generated by the NASA Ames Mars General Circulation Model (MGCM). The 2001 global dust storm was the earliest on record (Ls ~ 180°) and originated from local dust storms around the Hellas basin as the storm expanded asymmetrically to the east. Trajectories near Hellas and Claritas Fossae correspond with dust transport detected using satellite imagery. Forward trajectories at Ls = 184° from Hellas show flow to the south, transporting dust around the south polar cap, while after L¬s = 188° there is an eastward shift in propagation. Air parcel trajectories intersecting the surface during the dust storm may indicate the processes involved with global dust storms contributing to dust layers in the polar regions. Backward trajectories from Claritas Fossae reveal the dust activity in this region was the result of local dust storm activity instead of the propagation of dust eastward from the Hellas region.
Subjects/Keywords: Dust; HYSPLIT; Mars; Trajectories
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bruggeman, D. (2015). Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT. (Masters Thesis). San Jose State University. Retrieved from https://doi.org/10.31979/etd.9kn2-vwb2 ; https://scholarworks.sjsu.edu/etd_theses/4625
Chicago Manual of Style (16th Edition):
Bruggeman, David. “Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT.” 2015. Masters Thesis, San Jose State University. Accessed March 06, 2021.
https://doi.org/10.31979/etd.9kn2-vwb2 ; https://scholarworks.sjsu.edu/etd_theses/4625.
MLA Handbook (7th Edition):
Bruggeman, David. “Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT.” 2015. Web. 06 Mar 2021.
Vancouver:
Bruggeman D. Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT. [Internet] [Masters thesis]. San Jose State University; 2015. [cited 2021 Mar 06].
Available from: https://doi.org/10.31979/etd.9kn2-vwb2 ; https://scholarworks.sjsu.edu/etd_theses/4625.
Council of Science Editors:
Bruggeman D. Trajectories of Air Parcel Motions in Mars' Atmosphere Computed Using HYSPLIT. [Masters Thesis]. San Jose State University; 2015. Available from: https://doi.org/10.31979/etd.9kn2-vwb2 ; https://scholarworks.sjsu.edu/etd_theses/4625
Oregon State University
17.
Langdon, Brian B.
An evaluation of dust abatement materials used in Region 6.
Degree: MS, Civil Engineering, 1979, Oregon State University
URL: http://hdl.handle.net/1957/42467
Subjects/Keywords: Dust control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Langdon, B. B. (1979). An evaluation of dust abatement materials used in Region 6. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/42467
Chicago Manual of Style (16th Edition):
Langdon, Brian B. “An evaluation of dust abatement materials used in Region 6.” 1979. Masters Thesis, Oregon State University. Accessed March 06, 2021.
http://hdl.handle.net/1957/42467.
MLA Handbook (7th Edition):
Langdon, Brian B. “An evaluation of dust abatement materials used in Region 6.” 1979. Web. 06 Mar 2021.
Vancouver:
Langdon BB. An evaluation of dust abatement materials used in Region 6. [Internet] [Masters thesis]. Oregon State University; 1979. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1957/42467.
Council of Science Editors:
Langdon BB. An evaluation of dust abatement materials used in Region 6. [Masters Thesis]. Oregon State University; 1979. Available from: http://hdl.handle.net/1957/42467
Texas A&M University
18.
Chowdhury, Amira Yousuf.
Shock Interaction with Dust Layers.
Degree: PhD, Materials Science and Engineering, 2015, Texas A&M University
URL: http://hdl.handle.net/1969.1/155415
► Dust explosion hazards in areas where combustible dusts are found have caused loss of life and halted business operations in some instances. The elimination of…
(more)
▼ Dust explosion hazards in areas where combustible dusts are found have caused loss of life and halted business operations in some instances. The elimination of secondary
dust explosion hazards, i.e. reducing
dust dispersion, can be characterized in shock-tubes to understand shock-
dust interactions. For this reason, a new shock-tube test section was developed and integrated into an existing shock-tube facility. The test section has large windows to allow for the use of the shadowgraph technique to track
dust-layer growth behind a passing normal shock wave, and it is designed to handle an incident shock wave up to Mach 2 to impersonate real-industry scenarios. The characterization experiments presented herein demonstrate the advantages of the authors’ test techniques toward providing new physical insights over a wider range of data than what have been available heretofore in the literature.
First, the effect of shock strength on the
dust entrainment process was explored by subjecting limestone
dust to Mach numbers ranging from 1.10 to 1.60. Also, the effect of
dust-layer thickness on the entrainment process was observed by performing tests with two different layer depths, namely 3.2- and 12.7-mm thicknesses. New data were collected to develop correlations between the shock strength and the
dust entrainment height as a function of time for each layer depth. The longer observation time and higher camera framing rates led to the discovery of trends not previously observed by earlier studies, such as a clear transition time between the early, linear growth regime and a much-slower, average growth regime. This second regime is however accompanied by surface instabilities that can lead to a much larger variation in the edge of the
dust layer than seen in the early growth regime. In addition, for the linear growth regime, there was no significant difference in the
dust-layer height growth between the two layer thicknesses; however, the larger thickness led to higher growth rates and much larger surface instabilities at later times. Next, we conducted experiments to elucidate the effect of particle size and size polydispersity on
dust cloud formation phenomena behind blast waves. Through systematic modification of the span of the particle size distribution, the striking effect of polydispersity on the entrainment process was demonstrated. Moreover, correlations between linear
dust rise rate and particle size and size polydispersity have been developed. Finally, recommendations for numerical modelers of this field and NFPA 654, Standard for the Prevention of Fire and
Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids are provided for developing a better
dust explosion hazard assessment tool.
Advisors/Committee Members: Mannan, M. Sam (advisor), Petersen, Eric L (advisor), Cheng, Zhengdong (committee member), Jeong, Hae-Kwon (committee member).
Subjects/Keywords: Dust Explosion; Shock wave
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chowdhury, A. Y. (2015). Shock Interaction with Dust Layers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155415
Chicago Manual of Style (16th Edition):
Chowdhury, Amira Yousuf. “Shock Interaction with Dust Layers.” 2015. Doctoral Dissertation, Texas A&M University. Accessed March 06, 2021.
http://hdl.handle.net/1969.1/155415.
MLA Handbook (7th Edition):
Chowdhury, Amira Yousuf. “Shock Interaction with Dust Layers.” 2015. Web. 06 Mar 2021.
Vancouver:
Chowdhury AY. Shock Interaction with Dust Layers. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1969.1/155415.
Council of Science Editors:
Chowdhury AY. Shock Interaction with Dust Layers. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155415
University of Newcastle
19.
Chen, Xiaoling.
Experimental and numerical investigation of dust emissions from transfer chutes.
Degree: PhD, 2013, University of Newcastle
URL: http://hdl.handle.net/1959.13/1036786
► Research Doctorate - Doctor of Philosophy (PhD)
Transfer chutes are used extensively in belt conveyor systems to ensure the material loaded is discharged in a…
(more)
▼ Research Doctorate - Doctor of Philosophy (PhD)
Transfer chutes are used extensively in belt conveyor systems to ensure the material loaded is discharged in a centralised stream and in the same direction as the receiving conveyor. As concerns arise for the environment and occupational health and safety, the control of dust emissions from the belt conveyor system is a matter of high importance. Therefore, the performance of transfer chutes has a significant impact on not only the efficiency of conveyor belt systems, but on the level of fugitive dust emissions. The work presented investigates the feasibility of using a simulation method to predict the performance of transfer chutes, thereby achieving a better design. Scale model tests are carried out to provide the necessary information for the verification of the simulation results. Totally, there are six different chute configurations involved in the scale model tests. Several available simulation methods are applied to model the granular flow in transfer chutes, where both the advantages and disadvantages for each method are presented and discussed. A two-phase CFD simulation method is considered as a compromise solution, involving a mixture of the accuracy, time consumption and ease of use considerations. The appropriate models and modelling parameters of the two-phase CFD method for this particular system are determined according to the experimental results. Further potential to improve the design obtained from the results of scale model tests is investigated using simulation. The influences of the height of the stilling chamber, the length of the stilling chamber and the pattern of the curtains inside the stilling chamber on reducing dust emissions are briefly discussed and the effects of the control flap and the by-pass pipe are also investigated. The results reveal that the pattern of curtains placed has a great influence on lowering the air velocity at the chute outlet. The feasibility of the two-phase CFD on full scale transfer chute modelling is verified using results from site tests. The results indicate that the transfer chute performance regarding dust emission can be predicted by this method, providing a powerful design tool when used in conjunction with other methods used to analyse the transfer chute from a bulk material flow perspective.
Advisors/Committee Members: University of Newcastle. Faculty of Engineering & Built Environment, School of Engineering.
Subjects/Keywords: transfer chute; dust emission; CFD
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chen, X. (2013). Experimental and numerical investigation of dust emissions from transfer chutes. (Doctoral Dissertation). University of Newcastle. Retrieved from http://hdl.handle.net/1959.13/1036786
Chicago Manual of Style (16th Edition):
Chen, Xiaoling. “Experimental and numerical investigation of dust emissions from transfer chutes.” 2013. Doctoral Dissertation, University of Newcastle. Accessed March 06, 2021.
http://hdl.handle.net/1959.13/1036786.
MLA Handbook (7th Edition):
Chen, Xiaoling. “Experimental and numerical investigation of dust emissions from transfer chutes.” 2013. Web. 06 Mar 2021.
Vancouver:
Chen X. Experimental and numerical investigation of dust emissions from transfer chutes. [Internet] [Doctoral dissertation]. University of Newcastle; 2013. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1959.13/1036786.
Council of Science Editors:
Chen X. Experimental and numerical investigation of dust emissions from transfer chutes. [Doctoral Dissertation]. University of Newcastle; 2013. Available from: http://hdl.handle.net/1959.13/1036786
University of Johannesburg
20.
Du Plessis, Jan Leonard.
The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2854
M.Tech.
Subjects/Keywords: Dust allergy
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Du Plessis, J. L. (2009). The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2854
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Du Plessis, Jan Leonard. “The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy.” 2009. Thesis, University of Johannesburg. Accessed March 06, 2021.
http://hdl.handle.net/10210/2854.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Du Plessis, Jan Leonard. “The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy.” 2009. Web. 06 Mar 2021.
Vancouver:
Du Plessis JL. The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10210/2854.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Du Plessis JL. The efficacy of house dust mite 30CH in ameliorating the symptoms of dust allergy. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2854
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
North Carolina State University
21.
Williams, Brian Jeffrey.
Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium.
Degree: PhD, Physics, 2010, North Carolina State University
URL: http://www.lib.ncsu.edu/resolver/1840.16/6237
► Interstellar dust grains play a crucial role in the evolution of the galactic interstellar medium (ISM). Despite its importance, however, dust remains poorly understood in…
(more)
▼ Interstellar
dust grains play a crucial role in the evolution of the galactic interstellar medium (ISM). Despite its importance, however,
dust remains poorly understood in terms of its origin, composition, and abundance throughout the universe. Supernova remnants (SNRs) provide a laboratory for studying the evolution of
dust grains, as they are one of the only environments in the universe where it is possible to observe grains being both created and destroyed. SNRs exhibit collisionally heated
dust, allowing
dust to serve as a diagnostic both for grain physics and for the plasma conditions in the SNR. I present theoretical models of collisionally heated
dust which calculate grain emission as well as destruction rates. In these models, I incorporate physics such as nonthermal sputtering caused by grain motions through the gas, a more realistic approach to sputtering for small grains, and arbitrary grain compositions porous and composite grains. I apply these models to infrared and X-ray observations of Kepler's supernova and the Cygnus Loop in the galaxy, and SNRs 0509-67.5, 0519-69.0, and 0540-69.3 in the LMC. X-ray observations characterize the hot plasma while IR observations constrain grain properties and destruction rates. Such a multi-wavelength approach is crucial for a complete understanding of gas and
dust interaction and evolution. Modeling of both X-ray and IR spectra allows disentangling of parameters such as pre and postshock gas density, as well as swept-up masses of gas and
dust, and can provide constraints on the shock compression ratio. Observations also show that the
dust-to-gas mass ratio in the ISM is lower by a factor of several than what is inferred by extinction studies of starlight. Future observatories, such as the James Webb Space Telescope and the International X-ray Observatory, will allow testing of models far beyond what is possible now.
Advisors/Committee Members: John M. Blondin, Committee Member (advisor), Michael Shearer, Committee Member (advisor), Kazimierz J. Borkowski, Committee Co-Chair (advisor), Stephen P. Reynolds, Committee Co-Chair (advisor).
Subjects/Keywords: dust; Astrophysics; astronomy; supernova remnants
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Williams, B. J. (2010). Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/6237
Chicago Manual of Style (16th Edition):
Williams, Brian Jeffrey. “Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium.” 2010. Doctoral Dissertation, North Carolina State University. Accessed March 06, 2021.
http://www.lib.ncsu.edu/resolver/1840.16/6237.
MLA Handbook (7th Edition):
Williams, Brian Jeffrey. “Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium.” 2010. Web. 06 Mar 2021.
Vancouver:
Williams BJ. Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium. [Internet] [Doctoral dissertation]. North Carolina State University; 2010. [cited 2021 Mar 06].
Available from: http://www.lib.ncsu.edu/resolver/1840.16/6237.
Council of Science Editors:
Williams BJ. Supernova Remnants as a Probe of Dust Grains in the Interstellar Medium. [Doctoral Dissertation]. North Carolina State University; 2010. Available from: http://www.lib.ncsu.edu/resolver/1840.16/6237
University of Pretoria
22.
Ndenguma, Dickson
Daniel.
Computational
fluid dynamics model for controlling dust and methane in
underground coalmines.
Degree: Mechanical and Aeronautical
Engineering, 2011, University of Pretoria
URL: http://hdl.handle.net/2263/28135
► Airborne dust and methane are common problems in the underground coalmines. They pose health and safety risk to mining personnel, and a safety risk to…
(more)
▼ Airborne
dust and methane are common problems in the
underground coalmines. They pose health and safety risk to mining
personnel, and a safety risk to mining equipment as well. In order
to prevent these risks air borne
dust and methane concentrations
must be reduced to within the acceptable levels. In South Africa,
the
dust and methane concentration in coalmines should not exceed
2.0 mg/m³ and 0.5% per volume, respectively. Mine ventilation is
one of the popular ways of controlling both
dust and methane.
Different ventilation systems have been designed since the history
of underground coal mining. Unfortunately, none provides ultimate
solution to the
dust and methane problem, especially in the most
critical areas of the underground coalmine, like blind-end of the
heading and last through road. By changing airflow patterns and air
velocity, it is possible to obtain an optimum ventilation design
that can keep
dust and methane within the acceptable levels. Since
it is very difficult to conduct experiments in the underground
coalmine due to harsh environmental conditions and tight production
schedules, the designer made use of the Computational Fluid
Dynamics (CFD) modelling technique. The models were then
experimentally verified and validated using a scaled down model at
University of Pretoria. After verification further numerical
analysis was done to in order to device a method for determining
optimum fan positions for different heading dimensions. This study
proves that CFD can be used to model ventilation system of a scaled
down coalmine model. Therefore chances that this might be true for
the actual mine are very high but it needs to be investigated. If
this is found to be true then CFD modelling will be a very useful
tool in coalmine ventilation system research and
development.
Advisors/Committee Members: Dr J Dirker (advisor), Prof N D L Burger (advisor).
Subjects/Keywords: Fluid
dynamics;
Dust;
Methane;
UCTD
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ndenguma, D. (2011). Computational
fluid dynamics model for controlling dust and methane in
underground coalmines. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/28135
Chicago Manual of Style (16th Edition):
Ndenguma, Dickson. “Computational
fluid dynamics model for controlling dust and methane in
underground coalmines.” 2011. Masters Thesis, University of Pretoria. Accessed March 06, 2021.
http://hdl.handle.net/2263/28135.
MLA Handbook (7th Edition):
Ndenguma, Dickson. “Computational
fluid dynamics model for controlling dust and methane in
underground coalmines.” 2011. Web. 06 Mar 2021.
Vancouver:
Ndenguma D. Computational
fluid dynamics model for controlling dust and methane in
underground coalmines. [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2263/28135.
Council of Science Editors:
Ndenguma D. Computational
fluid dynamics model for controlling dust and methane in
underground coalmines. [Masters Thesis]. University of Pretoria; 2011. Available from: http://hdl.handle.net/2263/28135
Oregon State University
23.
Anderson, Charles Michael.
Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust.
Degree: PhD, Mechanical Engineering, 1973, Oregon State University
URL: http://hdl.handle.net/1957/45635
Subjects/Keywords: Dust control
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Anderson, C. M. (1973). Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/45635
Chicago Manual of Style (16th Edition):
Anderson, Charles Michael. “Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust.” 1973. Doctoral Dissertation, Oregon State University. Accessed March 06, 2021.
http://hdl.handle.net/1957/45635.
MLA Handbook (7th Edition):
Anderson, Charles Michael. “Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust.” 1973. Web. 06 Mar 2021.
Vancouver:
Anderson CM. Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust. [Internet] [Doctoral dissertation]. Oregon State University; 1973. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1957/45635.
Council of Science Editors:
Anderson CM. Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust. [Doctoral Dissertation]. Oregon State University; 1973. Available from: http://hdl.handle.net/1957/45635
24.
Sitembo, William.
Risk Factors Associated with Silicosis in Zambin former Mineworkers.
Degree: 2012, University of Zimbabwe
URL: http://dspace.unza.zm/handle/123456789/1226
► The risk of silicosis depends on a number of factors which include among others; the nature of the dust, the intensity and duration of exposure…
(more)
▼ The risk of silicosis depends on a number of factors which include among others; the nature of the dust, the intensity and duration of exposure as well as individual susceptibility. The association of these factors with silicosis vary from country to country and between regions being influenced mainly by work culture, environmental and safety conditions prevailing at worksites. This study aimed to determine the risk factors of silicosis in Zambian former copper mineworkers.
A retrospective cross-sectional study involving the review of 476 randomly selected records of all Zambian former copper mineworkers who attended medical examinations at Occupational Health Management Board in Kitwe, between the periods 1st January 2004 and 31st December 2008. Data was analysed using Epi Info version 3.3.2 statistical package. Data was described for silicosis by; current age, dates of certification and discharge, sex, service in various mining divisions, work-sites, job categories, and mean percent silica concentration.
The results showed a silicosis prevalence of 8.8percent (CI = 6.27 to 11.38). The study established an average age of 66 years in silicotics, as compared to 56 years in non-silicotics (p-value <0.001). The silicotics were found to have worked for a median 26 years while the non-silicotics’ median service stood at 21 years (p-value <0.001). For each additional year spent working for Mufulira or Chibuluma divisions, miners were16percentmore likelyto develop silicosis (OR = 1.16; CI = 1.06 to 1.26 and OR = 1.16; CI = 1.04 to 1.30 respectively). On each additional year spent working in the underground production areas, miners were 14percent (OR = 1.14; CI = 1.06 to 1.24) more likely to develop silicosis. Each year spent working as a lasher increased miners’ chances of developing silicosis by 31percent (OR = 1.31; CI = 1.12 to 1.54). Silicotics were exposed to 825percent silica-years as compared to 507percent silica-years in non-silicotics (p-value < 0.001).
Long service, working in Mufulira or Chibuluma division, working in the production area, working as a lasher and exposure to dust with high percent silica concentration are associated with silicosis in Zambian former miners. Efforts to reduce the silicosis burden among the former miners should address the above identified risk factors. These include reducing years of service and providing personal protective equipment for workers in work-areas with high silica content
Subjects/Keywords: Silicosis; Lungs – Dust Disease; Silicotics
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sitembo, W. (2012). Risk Factors Associated with Silicosis in Zambin former Mineworkers. (Thesis). University of Zimbabwe. Retrieved from http://dspace.unza.zm/handle/123456789/1226
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sitembo, William. “Risk Factors Associated with Silicosis in Zambin former Mineworkers.” 2012. Thesis, University of Zimbabwe. Accessed March 06, 2021.
http://dspace.unza.zm/handle/123456789/1226.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sitembo, William. “Risk Factors Associated with Silicosis in Zambin former Mineworkers.” 2012. Web. 06 Mar 2021.
Vancouver:
Sitembo W. Risk Factors Associated with Silicosis in Zambin former Mineworkers. [Internet] [Thesis]. University of Zimbabwe; 2012. [cited 2021 Mar 06].
Available from: http://dspace.unza.zm/handle/123456789/1226.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sitembo W. Risk Factors Associated with Silicosis in Zambin former Mineworkers. [Thesis]. University of Zimbabwe; 2012. Available from: http://dspace.unza.zm/handle/123456789/1226
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Colorado State University
25.
Lerach, David Gregory.
Simulating southwestern U.S. desert dust influences on severe, tornadic storms.
Degree: PhD, Atmospheric Science, 2012, Colorado State University
URL: http://hdl.handle.net/10217/67575
► In this study, three-dimensional numerical simulations were performed using the Regional Atmospheric Modeling System (RAMS) model to investigate possible southwestern U.S. desert dust impacts on…
(more)
▼ In this study, three-dimensional numerical simulations were performed using the Regional Atmospheric Modeling System (RAMS) model to investigate possible southwestern U.S. desert
dust impacts on severe, tornadic storms. Initially, two sets of simulations were conducted for an idealized supercell thunderstorm. In the first set, two numerical simulations were performed to assess the impacts of increased aerosol concentrations acting as cloud condensation nuclei (CCN) and giant CCN (GCCN). Initial profiles of CCN and GCCN concentrations were set to represent "clean" continental and aerosol-polluted environments, respectively. With a reduction in warm- and cold-rain processes, the polluted environment produced a longer-lived supercell with a well-defined rear flank downdraft (RFD) and relatively weak forward flank downdraft (FFD) that produced weak evaporative cooling, a weak cold-pool, and an EF-1 tornado. The clean environment produced no tornado and was less favorable for tornadogenesis. In the second ensemble, aerosol microphysical effects were put into context with those of convective available potential energy (CAPE) and low-level moisture. Simulations initialized with greater low-level moisture and higher CAPE produced significantly stronger precipitation, which resulted in greater evaporation and associated cooling, thus producing stronger cold-pools at the surface associated with both the forward- and rear-flank downdrafts. Simulations initialized with higher CCN concentrations resulted in reduced warm rain and more supercooled water aloft, creating larger anvils with less ice mass available for precipitation. These simulated supercells underwent less evaporative cooling within downdrafts and produced weaker cold-pools compared to the lower CCN simulations. Tornadogenesis was related to the size, strength, and location of the FFD- and RFD-based cold-pools. The combined influence of low-level moisture and CAPE played a considerably larger role on tornadogenesis compared to aerosol impacts. However, the aerosol effect was still evident. In both idealized model ensembles, the strongest, longest-lived tornado-like vortices were associated with warmer and weaker cold-pools, higher CAPE, and less negative buoyancy in the near-vortex environment compared to those storms that produced shorter-lived, weaker vortices. A final set of nested grid simulations were performed to evaluate
dust indirect microphysical and direct radiative impacts on a severe storms outbreak that occurred during 15-16 April 2003 in Texas and Oklahoma. In one simulation, neither
dust microphysical nor radiative effects were included (CTL). In a second simulation, only
dust radiative effects were considered (RAD). In a third simulation, both
dust radiative and indirect microphysical effects were simulated (DST), where
dust was allowed to serve as CCN, GCCN, and ice nuclei (IN). Fine mode
dust serving as CCN reduced warm rain formation in the DST simulation. Thus, cloud droplets were transported into the mixed phase region, enhancing…
Advisors/Committee Members: Cotton, William R. (advisor), Rutledge, Steven A. (committee member), Kreidenweis, Sonia M. (committee member), Roesner, Larry A. (committee member).
Subjects/Keywords: aerosol; tornadoes; supercells; dust
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lerach, D. G. (2012). Simulating southwestern U.S. desert dust influences on severe, tornadic storms. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/67575
Chicago Manual of Style (16th Edition):
Lerach, David Gregory. “Simulating southwestern U.S. desert dust influences on severe, tornadic storms.” 2012. Doctoral Dissertation, Colorado State University. Accessed March 06, 2021.
http://hdl.handle.net/10217/67575.
MLA Handbook (7th Edition):
Lerach, David Gregory. “Simulating southwestern U.S. desert dust influences on severe, tornadic storms.” 2012. Web. 06 Mar 2021.
Vancouver:
Lerach DG. Simulating southwestern U.S. desert dust influences on severe, tornadic storms. [Internet] [Doctoral dissertation]. Colorado State University; 2012. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10217/67575.
Council of Science Editors:
Lerach DG. Simulating southwestern U.S. desert dust influences on severe, tornadic storms. [Doctoral Dissertation]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/67575
Colorado State University
26.
Funk, Sara.
Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor.
Degree: MS(M.S.), Environmental and Radiological Health Sciences, 2011, Colorado State University
URL: http://hdl.handle.net/10217/47272
► This pilot study measured the impact of seasonal ventilation changes on concentrations of organic dust, endotoxin and bacteria in one modern dairy milking parlor. Pyrosequencing,…
(more)
▼ This pilot study measured the impact of seasonal ventilation changes on concentrations of organic
dust, endotoxin and bacteria in one modern dairy milking parlor. Pyrosequencing, a new non-target specific molecular methodology was used to characterize airborne bioaerosols. Area samples for inhalable
dust, respirable
dust, endotoxin, and bacteria were collected in one modern dairy parlor during both summer and winter seasons. Five sampling sessions were performed at approximately weekly intervals during each season. The summer season included an open facility with fresh mechanical air ventilation. The winter season consisted of a closed facility with no fresh air ventilation and forced heat. Aerosol size distributions, air velocity inside the parlor, humidity, temperature, and CO2 were also sampled on each trip. Two-way ANOVA was performed to test statistically significant differences between variables. No significant differences between mean concentrations of inhalable
dust, respirable
dust, or bacteria were seen by season. Endotoxin showed a near significant difference (p=0.06). CO2 concentration doubled during the winter season as compared to the summer (p<0.001) due to reduced ventilation. The aerosol size distribution did not vary between seasons (MMOD=12µm) indicating that seasonal ventilation changes do not affect the particle size distribution. The most common bacterial genera in both seasons were Clostridium (anaerobic), Oscillibacter and Staphylococcus - all Gram positive bacteria. Gram-positive bacterial genera occurred more frequently during the summer than winter seasons. Gram-negative bacteria cell counts increased in the winter season. Average concentrations of total bacteria in the facility during summer and winter were 2839 and 7008 counts/m3, respectively. This study was the first to apply Pyrosequencing to measure bioaerosols in a dairy environment. The diversity of bacteria and predominance of Gram-positive bacteria is consistent with studies in swine and poultry facilities. Concentrations of
dust, endotoxin, and bacteria were low during both seasons in this milking parlor, most likely due to the new construction of the facility. These study results will inform the design of future comprehensive studies of aerosol exposure interventions in dairy operations. Understanding these aerosol exposures and potential interventions is important for reducing respiratory disease among workers in the dairy industry.
Advisors/Committee Members: Reynolds, Stephen J. (advisor), Roman-Muniz, Noa (committee member), Volckens, John (committee member).
Subjects/Keywords: bacteria; pyrosequencing; endotoxin; dust; dairy
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Funk, S. (2011). Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/47272
Chicago Manual of Style (16th Edition):
Funk, Sara. “Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor.” 2011. Masters Thesis, Colorado State University. Accessed March 06, 2021.
http://hdl.handle.net/10217/47272.
MLA Handbook (7th Edition):
Funk, Sara. “Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor.” 2011. Web. 06 Mar 2021.
Vancouver:
Funk S. Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor. [Internet] [Masters thesis]. Colorado State University; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10217/47272.
Council of Science Editors:
Funk S. Evaluation of seasonal ventilation changes and their effect on ambient dust, endotoxin and bioaerosol concentrations in a dairy parlor. [Masters Thesis]. Colorado State University; 2011. Available from: http://hdl.handle.net/10217/47272
Université de Neuchâtel
27.
Parrat, Daniel.
Atomic force microscopy for charaterizing dust particles of
the martian arctic soils.
Degree: 2007, Université de Neuchâtel
URL: http://doc.rero.ch/record/11225
► Cette thèse traite du développement, de la fabrication et de la caractérisation d'un microscope à force atomique (AFM) pour l'exploration de la planète Mars. A…
(more)
▼ Cette thèse traite du développement, de la fabrication
et de la caractérisation d'un microscope à force atomique (AFM)
pour l'exploration de la planète Mars. A bord de la mission
Phoenix, cet instrument devrait recueillir prochainement de
précieuses informations sur la taille et la forme de fines
particules de poussière présentes à la surface de Mars et en
suspension dans l'atmosphère. La microscopie à force atomique est
une technique d'imagerie tridimensionnelle permettant d'établir
avec une très haute résolution la topographie de l'échantillon
mesuré. Elle se base sur la détection des forces atomiques agissant
entre l'échantillon et une pointe microscopique balayée sur
celui-ci. Grâce à sa formidable résolution, cette technique est
utilisée dans des nombreuses applications, allant de l'industrie
des semi-conducteurs à la biologie. La taille d'un AFM, sa relative
fragilité et sa complexité d'utilisation ne favorise pas
intrinsèquement son utilisation dans l'espace. Grâces aux progrès
technologiques dans le domaine des microsystèmes, un maximum de
fonctionnalité a pourtant pu être incorporé dans un instrument de
taille très modeste.L'AFM présenté dans cette dissertation est basé
sur un modèle antérieur présentant quelques problèmes de balayage à
basse température. Grâce à un système de suspension en polyimide,
un matériau connu pour sa stabilité en température, ce problème a
été résolu pour le nouvel instrument. Des déformations non
linéaires du plan de balayage ayant été observées, un logiciel de
correction a été mis au point. Avant d'être délivré à la NASA,
l'instrument a également passé avec succès les essais en
environnement propres à la mission Phoenix. En plus des composantes
matérielles de l'AFM, les commandes permettant de manœuvrer
l'instrument de manière autonome ont été crées et testées en
collaboration avec nos partenaires. Le fonctionnement autonome de
l'appareil a ensuite été démontré sur un banc d'essai ainsi que sur
une reproduction de l'atterrisseur de la mission. En parallèle aux
développements techniques, la caractérisation de l'AFM a été
réalisée par la mesure de différents échantillons. Les mesures
exécutées sur des particules fixées artificiellement à leur
substrat ont démontrées que l'instrument pouvait mesurer des
particules de diamètre compris entre 0.1 et 5 micromètres. Comme la
forme et la taille des particules étaient affectées par la
géométrie de la pointe, des algorithmes corrigeant ces artefacts
ont été crées et appliqués à des images. La distribution de taille
des particules d'une image a également été déterminée avec succès.
Des mesures d'échantillons analogues à ceux qui devraient être
observés sur Mars ont indiqué que l'instrument ne pourrait pas
prendre des images de n'importe quel échantillon, la taille des
particules, leur arrangement sur le substrat ainsi que leur
adhésion étant critiques. En particulier, il a été observé que des
particules empilèes les unes sur les autres étaient très difficiles
à mesurer, et constituaient un risque pour l'instrument.
Finalement, des solutions…
Advisors/Committee Members: Urs (Dir.).
Subjects/Keywords: dust particles
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Parrat, D. (2007). Atomic force microscopy for charaterizing dust particles of
the martian arctic soils. (Thesis). Université de Neuchâtel. Retrieved from http://doc.rero.ch/record/11225
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Parrat, Daniel. “Atomic force microscopy for charaterizing dust particles of
the martian arctic soils.” 2007. Thesis, Université de Neuchâtel. Accessed March 06, 2021.
http://doc.rero.ch/record/11225.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Parrat, Daniel. “Atomic force microscopy for charaterizing dust particles of
the martian arctic soils.” 2007. Web. 06 Mar 2021.
Vancouver:
Parrat D. Atomic force microscopy for charaterizing dust particles of
the martian arctic soils. [Internet] [Thesis]. Université de Neuchâtel; 2007. [cited 2021 Mar 06].
Available from: http://doc.rero.ch/record/11225.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Parrat D. Atomic force microscopy for charaterizing dust particles of
the martian arctic soils. [Thesis]. Université de Neuchâtel; 2007. Available from: http://doc.rero.ch/record/11225
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
George Mason University
28.
Jordan, Margaret E.
Two Problems in Interstellar Grain Alignment
.
Degree: 2011, George Mason University
URL: http://hdl.handle.net/1920/6183
► Starlight observed through the diffuse interstellar medium of the Galaxy is polarized and the polarization appears to track the Galactic magnetic field. This polarized starlight…
(more)
▼ Starlight observed through the diffuse interstellar medium of the Galaxy is polarized and
the polarization appears to track the Galactic magnetic field. This polarized starlight has
been associated with non-spherical
dust grains aligned with the magnetic field, and both
grain aligning and disaligning mechanisms have been explored to explain the polarization.
Radiative torques due to anisotropic stellar radiation incident on asymmetric grains appears
to play a dominant role in alignment. Here, we investigate the importance relative to
radiative torque alignment, of two possible effects on the grain’s alignment. The first is due
to recoil torques as electrons and H atoms leave the grain surface and the second is due to
a grains’s time-varying electric dipole moment.
A grain irradiated by starlight may experience photoelectric emission, as well as photodesorption
of adsorbed surface H atoms. Each ejection event imparts an angular impulse
to the grain; integrated over the grain surface, they produce non-zero net recoil torques in
the grain. The effects of these torques on grain alignment is the first
subject of this dissertation.
To evaluate these torques we constructed models of spheroidal grains irradiated by an
anisotropic radiation field, and evaluated the resulting electric field intensities immediately
below and immediately above the grain surface. The variation of the internal electric field
intensity with surface position provides a measure of the photoelectric emission asymmetry.
We used this asymmetry to estimate the photoelectric recoil torque on the grain. In the
case of photodesorption, variation of the external electric field with surface position is used to
estimate the recoil torque due to photodesorption. The maximum photoelectric torque was
found to be ∼ 35% the radiative torque, and the maximum photodesorption torque was ∼
30% of the photoemission torque. Because we set the conditions to maximize the torques in
order to judge their relative importance, the torque contributions may be overestimated and
actual torques may be on the order of 10% or less of radiative torques. Given this relatively
small contribution to the total torque and that additional model uncertainties contribute at
comparable or greater levels, we conclude that photoelectric and photodesorption torques
need not be included in radiative torque alignment models.
Charging processes, both the capture and emission of electrons from the grain, result
in a net charge and an electric dipole moment that continually change for the grain. Recent
analysis has shown that this changing dipole moment, in a grain drifting across the
Galactic magnetic field lines, has the potential to disalign the grain. In the second half of
this dissertation, the effects of the time-varying electric dipole on grain disalignment are
explored. Previously, disalignment was presumed to be due principally to random collisions
with interstellar gas atoms. Any successful alignment mechanism would have to align the
grain on a timescale…
Advisors/Committee Members: Weingartner, Joseph C (advisor).
Subjects/Keywords: ISM;
dust;
grain;
alignment;
interstellar
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jordan, M. E. (2011). Two Problems in Interstellar Grain Alignment
. (Thesis). George Mason University. Retrieved from http://hdl.handle.net/1920/6183
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Jordan, Margaret E. “Two Problems in Interstellar Grain Alignment
.” 2011. Thesis, George Mason University. Accessed March 06, 2021.
http://hdl.handle.net/1920/6183.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Jordan, Margaret E. “Two Problems in Interstellar Grain Alignment
.” 2011. Web. 06 Mar 2021.
Vancouver:
Jordan ME. Two Problems in Interstellar Grain Alignment
. [Internet] [Thesis]. George Mason University; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1920/6183.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Jordan ME. Two Problems in Interstellar Grain Alignment
. [Thesis]. George Mason University; 2011. Available from: http://hdl.handle.net/1920/6183
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Hong Kong University of Science and Technology
29.
Su, Lin ENVR.
A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system.
Degree: 2017, Hong Kong University of Science and Technology
URL: http://repository.ust.hk/ir/Record/1783.1-100375
;
https://doi.org/10.14711/thesis-991012564769603412
;
http://repository.ust.hk/ir/bitstream/1783.1-100375/1/th_redirect.html
► Dust particles are increasingly considered as having important effects on weather through their influence on atmospheric dynamics, radiation budget, clouds and precipitation. As a major…
(more)
▼ Dust particles are increasingly considered as having important effects on weather through their influence on atmospheric dynamics, radiation budget, clouds and precipitation. As a major dust contributor in the world, East Asian dust is considered to play a key role in determining global and regional dust variations, and impose significant effects on regional or even global weather system. This thesis presents the work on improving the numerical simulation of dust activity and its effects over East Asia in a regional modeling system. Large uncertainties exist in numerical dust emission simulations over East Asia due to errors in physical parameterizations or model configurations. The sensitivity of the Weather Research and Forecast model coupled with Chemistry module (WRF-Chem) to different dust emission schemes and soil data is investigated in this study, in order to quantify the uncertainties and look for a better configuration for stable long-term dust simulation over East Asia. Dust particles are considered as effective ice nuclei, which play an important part in ice nucleation process in the atmosphere, affecting the formation and evolution of ice and mixed-phase clouds. However, there is no effective and efficient way to evaluate this microphysical effect of dust in regional models. To fill the gap, a coupled dust-microphysics scheme is implemented into WRF-Chem, enabling the model to estimate the effect of dust in atmospheric microphysical processes, especially ice nucleation process within ice clouds and mixed-phase clouds. Further sensitivity experiments are carried out to optimize the parameters in the ice nucleation scheme. This work substantially improves the capability of WRF-Chem in simulating atmospheric ice water content, cloud cover, and cloud radiative effect enhanced by dust. Based on the work above, the full effects of dust aerosol, including direct radiative effect, cloud radiative effect, and indirect microphysics effect, on the weather system over East Asia during a typical dust-intensive period are evaluated. This is the first time that the microphysical and full effects of dust can be numerically estimated in East Asia. The comparison with comprehensive stationary and satellite-observations reveals that the model is capable of well reproducing dust emission, surface PM10 concentration during dust events. Furthermore, the model has a reasonable performance in simulating the dust-induced modification on optical properties, such as AOD and extinction coefficient over East Asia during dust events. The model yields the best performance in dust simulation with Shao’s emission scheme and USGS soil data. By comparing with satellite-observations, the GOCART-Thompson microphysics scheme is demonstrated to remarkably improve the performance of the model in simulating the atmospheric ice water content, with effect of dust taken into account in the atmospheric microphysical processes. The comparison between observational and simulated precipitation at over 50 meteorological stations over China…
Subjects/Keywords: Dust
; Environmental aspects
; Atmospheric nucleation
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Su, L. E. (2017). A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system. (Thesis). Hong Kong University of Science and Technology. Retrieved from http://repository.ust.hk/ir/Record/1783.1-100375 ; https://doi.org/10.14711/thesis-991012564769603412 ; http://repository.ust.hk/ir/bitstream/1783.1-100375/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Su, Lin ENVR. “A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system.” 2017. Thesis, Hong Kong University of Science and Technology. Accessed March 06, 2021.
http://repository.ust.hk/ir/Record/1783.1-100375 ; https://doi.org/10.14711/thesis-991012564769603412 ; http://repository.ust.hk/ir/bitstream/1783.1-100375/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Su, Lin ENVR. “A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system.” 2017. Web. 06 Mar 2021.
Vancouver:
Su LE. A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system. [Internet] [Thesis]. Hong Kong University of Science and Technology; 2017. [cited 2021 Mar 06].
Available from: http://repository.ust.hk/ir/Record/1783.1-100375 ; https://doi.org/10.14711/thesis-991012564769603412 ; http://repository.ust.hk/ir/bitstream/1783.1-100375/1/th_redirect.html.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Su LE. A numerical study of dust over East Asia : the role of dust in ice nucleation within clouds and its effects on the regional weather system. [Thesis]. Hong Kong University of Science and Technology; 2017. Available from: http://repository.ust.hk/ir/Record/1783.1-100375 ; https://doi.org/10.14711/thesis-991012564769603412 ; http://repository.ust.hk/ir/bitstream/1783.1-100375/1/th_redirect.html
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Loughborough University
30.
Qasem, Hassan.
Effect of accumulated dust on the performance of photovoltaic modules.
Degree: PhD, 2013, Loughborough University
URL: http://hdl.handle.net/2134/11735
► Dust accumulation on photovoltaic (PV) modules and its effect on their performance are of high concern for regions with a high rate of dust, low…
(more)
▼ Dust accumulation on photovoltaic (PV) modules and its effect on their performance are of high concern for regions with a high rate of dust, low frequency and intensity of rain. In this thesis, the effect of dust on PV modules is investigated with respect to dust concentration and spectral transmittance. The measured spectral transmittance of the dust sample shows spectral attenuation effect that varies at different wavelengths. This effect is explained by the particle size distribution of the dust samples: At shorter wavelengths more light is scattered due to the effect of the smaller particles. This effect has a major impact on the PV module as it affects PV technologies with a wider band-gap more than those of a narrower band-gap. The effect of dust is accumulative, i.e. PV module performance is reduced by increasing deposition over time or until it's cleared manually or by rain. The tilt angle of the PV installation plays a major role in the amount of dust accumulated on the devices, where higher tilt angles result in decreased dust concentrations. This effect is demonstrated in outdoor measurements where tilted modules had lower losses in daily as well as total array yield. It is also shown that tilted modules benefit from precipitation more than horizontal modules. However over the exposure period the modules did not show any clear aging effect caused specifically from dust accumulation or exhibit any seasonal variation. Different tilt angles can produce varying non-uniform dust patterns on the device surface. This effect and its pattern over long and short periods of exposure are investigated by means of spatial three dimensional modelling. The simulations compare two dust accumulation patterns that represent a short exposure to a single dusty day (one day) and a long exposure of dust (3 months). Out of the two patterns, the long exposure patterns showed higher losses of 19.4% in comparison to 14.8% for the short exposure. The simulation also showed that dust accumulation that promotes high concentration of dust at the bottom of the PV modules where it covers a full cell has a high risk of triggering hot spots and thus risks permanent module damage. A dust correction model for energy prediction is developed. The model takes into consideration dust concentration, spectral attenuation effect of dust, PV technology, and various meteorological variables. The modified spectral transmittances of the dust were incorporated into the model in the form of pre-measured data. This means in this work samples collected in Kuwait were measured and used to generate the input. The model is compared against the outdoor measured data and a good agreement between measurements iv and simulations is demonstrated. Using this model two procedures were developed. The first evaluates the uncertainties associated with dust over long periods of time. The second is to find the optimised cleaning schedule and frequency of cleaning based on acceptable yield loss margins over the simulated period of time. The optimisation of the cleaning…
Subjects/Keywords: 621.3815; Photovoltaic; Dust; Accumulation
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Qasem, H. (2013). Effect of accumulated dust on the performance of photovoltaic modules. (Doctoral Dissertation). Loughborough University. Retrieved from http://hdl.handle.net/2134/11735
Chicago Manual of Style (16th Edition):
Qasem, Hassan. “Effect of accumulated dust on the performance of photovoltaic modules.” 2013. Doctoral Dissertation, Loughborough University. Accessed March 06, 2021.
http://hdl.handle.net/2134/11735.
MLA Handbook (7th Edition):
Qasem, Hassan. “Effect of accumulated dust on the performance of photovoltaic modules.” 2013. Web. 06 Mar 2021.
Vancouver:
Qasem H. Effect of accumulated dust on the performance of photovoltaic modules. [Internet] [Doctoral dissertation]. Loughborough University; 2013. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2134/11735.
Council of Science Editors:
Qasem H. Effect of accumulated dust on the performance of photovoltaic modules. [Doctoral Dissertation]. Loughborough University; 2013. Available from: http://hdl.handle.net/2134/11735
◁ [1] [2] [3] [4] [5] … [42] ▶
. 
Open Access Theses and Dissertations