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Georgia Tech
1.
Zhao, Shiliang.
Effects of zinc impurities on the structure and reactivity of manganese oxides.
Degree: PhD, Earth and Atmospheric Sciences, 2018, Georgia Tech
URL: http://hdl.handle.net/1853/59925 
► Manganese (Mn) oxides are among the most ubiquitous and reactive mineral phases in natural environments. They can significantly influence the cycling of critical nutrients (such…
(more)
▼ Manganese (
Mn)
oxides are among the most ubiquitous and reactive mineral phases in natural environments. They can significantly influence the cycling of critical nutrients (such as carbon and nitrogen), as well as the transport and fate of a wide range of metals and organic contaminants. The structure and reactivity of
Mn oxides have been extensively studied. However, most studies used pure
Mn oxide minerals, which are not commonly found in geological or engineering settings. Considering the prevalent interactions between metal cations and
Mn oxides in the natural environments, it is highly desired to obtain an in-depth understanding on the effects of metal impurities on the structure and reactivity of
Mn oxides, which will provide a better understanding of a range of biogeochemical processes involving
Mn oxides under complex environmental conditions. This dissertation systematically explored the effects of Zn coprecipitation on the structure, reactivity, and transformation of biotic and abiotic
Mn oxides, and compared these with the effects of Zn sorption on
Mn oxides. Among all transition metals that are commonly found to associate with
Mn oxides (Co, Ni, Cu, Fe, Zn), Zn is the least compatible with
Mn oxide layers, and can cause significant structure modifications in
Mn oxides during coprecipitation. This research used a suite of complementary microscopy, spectroscopy, and scattering techniques to probe the changes in
Mn oxide surface, morphology, and structure properties, such as surface area, surface charge, particle size, morphology, oxidation state, phase, structural order, vacancy site density, and local coordination environment. Significant
Mn oxide structural modifications by Zn coprecipitation were observed, such as decreased particle size, increased average oxidation state, and increased vacancy site density. Based on the observed structure modifications, controlled laboratory sorption experiments were conducted using cation (Cd) and anion probes (AsO43- and PO43-) to elucidate the effects of Zn coprecipitation on the sorptive reactivity of
Mn oxides. The kinetics and pathways of Mn2+-induced reductive transformation of Zn-coprecipitated
Mn oxides were also investigated, in order to assess the long-term stability and reactivity of the
oxides. In summary, compared to pure oxide phase, Zn-coprecipitation induced significant structural modifications of
Mn oxides, resulting in significantly modified sorptive reactivity, redox reactivity, and transformation kinetics and pathways. Such effects of metal impurities might be common and should also be evaluated for other metals that commonly associate with
Mn oxides. The roles of
Mn oxides in regulating nutrient, metal, and organic fate and transport, as well as
Mn biogeochemical cycling itself, should also be re-visited and take the impacts of metal impurities into consideration.
Advisors/Committee Members: Tang, Yuanzhi (advisor), Taillefert, Martial (committee member), Reinhard, Chris (committee member), Glass, Jennifer (committee member), Zhu, Mengqiang (committee member).
Subjects/Keywords: Zinc impurities; Mn oxides
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APA (6th Edition):
Zhao, S. (2018). Effects of zinc impurities on the structure and reactivity of manganese oxides. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59925
Chicago Manual of Style (16th Edition):
Zhao, Shiliang. “Effects of zinc impurities on the structure and reactivity of manganese oxides.” 2018. Doctoral Dissertation, Georgia Tech. Accessed December 14, 2019.
http://hdl.handle.net/1853/59925.
MLA Handbook (7th Edition):
Zhao, Shiliang. “Effects of zinc impurities on the structure and reactivity of manganese oxides.” 2018. Web. 14 Dec 2019.
Vancouver:
Zhao S. Effects of zinc impurities on the structure and reactivity of manganese oxides. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/1853/59925.
Council of Science Editors:
Zhao S. Effects of zinc impurities on the structure and reactivity of manganese oxides. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/59925
University of Saskatchewan
2.
Dangeti, Sandeep Raja 1991-.
BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES.
Degree: 2017, University of Saskatchewan
URL: http://hdl.handle.net/10388/8335
► Manganese (Mn) is frequently detected in its reduced form, aqueous Mn(II), in groundwaters used as drinking water in Canada. Excess Mn(II) poses the potential risks…
(more)
▼ Manganese (
Mn) is frequently detected in its reduced form, aqueous
Mn(II), in groundwaters used as drinking water in Canada. Excess
Mn(II) poses the potential risks of water discolouration, infrastructure corrosion, and health problems, as uncontrolled
Mn(II) oxidation occurs and produces solid
Mn(III/IV)-oxide precipitates in water supplies. As a solution for
Mn(II) in groundwater, biofiltration technology has been considered globally to promote microbially mediated
Mn(II) oxidation and produce solid
Mn(III/IV)
oxides that can be filtered out. However, previous studies have consistently reported that the biofiltration of cold groundwater with high
Mn(II) and coexisting metal concentrations (typically Fe(II)) is challenging at low temperatures below 15 °C.
Diverse cold-adapted manganese-oxidizing bacteria (MnOB) are ubiquitous in cold groundwater. The biofiltration of cold
Mn(II)-rich groundwater, which relies on the onset, acclimation and acceleration of
Mn(II) removal associated with the enrichment of cold-adapted MnOB and biofilter media ripening in the field, has not been extensively understood.
The objectives of this research were therefore (1) to elucidate the onset, acclimation, and acceleration of
Mn(II) oxidation (removal) from cold, natural Fe(II)- and
Mn(II)-rich groundwater (4 to 8 °C) continuously fed into a two-stage pilot-scale biofiltration unit operated in the field at varying low on-site temperatures (8–14.8 °C) at the Langham Water Treatment Plant, Saskatchewan (Canada), (2) to characterize the microbial communities in the
Mn and Fe biofilters and incoming groundwater, as well as in the surface coatings on field-ripened filter media, and (3) to explore the potential enhancement of biological and physicochemical
Mn(II) oxidation in the field biofiltration unit.
Over the course of the 183-day pilot-scale biofiltration experiment in the field, the onset of
Mn(II) removal from the cold groundwater commenced at 8 °C in the
Mn filter after 29 days elapsed and after complete Fe(II) removal through the Fe filter. The
Mn filter (1.55 m high and 0.3 m in diameter) reached steady-state functioning after 97 days, consistently exhibiting a high
Mn(II)-removal efficiency of 97±0.9%. A gradual shift in redox-pH conditions in the
Mn filter, to oxidation-reduction potential (ORP) values over 300 mV, favoured biological
Mn(II) oxidation, the growth of viable MnOB populations, and an increase in microbial metabolic activity estimated by the adenosine triphosphate (ATP) assay. These changes reflected enhanced biological
Mn(II) oxidation at the low on-site temperatures. However, the empty bed contact time (EBCT) first-order rate constants (k) for
Mn(II) removal were very low, in the range of 10-6 and 10-5 min-1, with a long half-life of 40 days, even though the
Mn(II) removal efficiency was consistently at 97%. The
Mn(II) removal rate constant accelerated to 0.21 min-1 with a very short half-life of 3.31 minutes at 11±0.6 °C, immediately after three consecutive backwashes and injections of backwash sludge slurry…
Advisors/Committee Members: Chang, Wonjae, McBeth, Joyce, Ferguson, Grant, Fonstad, Terry, Soltan, Jafar, Hawkes, Chris.
Subjects/Keywords: Manganese; Biofiltration; Cold groundwaters; Microbial communities; Mn-oxides; Birnessite; Biological Mn(II) oxidation; Physico-chemical Mn(II) oxidation; Low temperatures; Mn-oxidizing bacteria; Accelerated Mn(II) kinetics; Filter ripening
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APA (6th Edition):
Dangeti, S. R. 1. (2017). BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/8335
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):
Dangeti, Sandeep Raja 1991-. “BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES.” 2017. Thesis, University of Saskatchewan. Accessed December 14, 2019.
http://hdl.handle.net/10388/8335.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Dangeti, Sandeep Raja 1991-. “BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES.” 2017. Web. 14 Dec 2019.
Vancouver:
Dangeti SR1. BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES. [Internet] [Thesis]. University of Saskatchewan; 2017. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10388/8335.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Dangeti SR1. BIOFILTRATION TREATMENT FOR IRON- AND MANGANESE-RICH GROUNDWATER AT LOW ON-SITE TEMPERATURES. [Thesis]. University of Saskatchewan; 2017. Available from: http://hdl.handle.net/10388/8335
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Delaware
3.
Li, Hui.
Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
.
Degree: 2018, University of Delaware
URL: http://udspace.udel.edu/handle/19716/23968
► Glyphosate is a milestone product developed and introduced into the herbicidal industry by John Franz in the 1970s. It has been widely and heavily applied…
(more)
▼ Glyphosate is a milestone product developed and introduced into the herbicidal industry by John Franz in the 1970s. It has been widely and heavily applied (e.g., ~280 million pounds in the U.S. in 2015) in agriculture and horticulture and drifted residues are found frequently in soils and other environments. Since the carcinogenicity of glyphosate has undergone intense debate and regulatory agencies have not yet reached consensus, studies on the fate of unreacted glyphosate in the environment are not only necessary but also urgent. ☐ Manganese oxides are of particular importance in abiotic degradation of glyphosate and some of its intermediate degradation products. In this dissertation research, birnessite, δ-MnO2, and ferrihydrite coated with δ-MnO2 were used to investigate degradation kinetics, preference in degradation pathways, and to identify source signature of glyphosate and its two products: aminomethylphosphonic acid (AMPA) and orthophosphate. Advanced instrumentation such as phosphate oxygen isotope ratios were used to determine the isotope signatures of parent and daughter products. Similarly, nuclear magnetic resonance (NMR) spectroscopy and high-performance liquid chromatography (HPLC) were utilized to identify and quantify degradation products, and density functional theory (DFT) calculations were used to investigate the bond critical point (BCP) properties of the C‒N bond in glyphosate and Mn(IV)-complexed glyphosate. ☐ The oxygen isotope ratios (δ18OP) of orthophosphate derived from glyphosate clearly demonstrated that the one external oxygen atom in each released orthophosphate was derived from ambient water, not from dissolved oxygen or minerals, with the other three oxygen atoms inherited from glyphosate. Orthophosphate derived from all commercial glyphosate studied had unusually light δ18OP values (3.91–9.30 ‰ VSMOW), which are distinct from many other sources of orthophosphates (varying between 16–24 ‰) known so far. These results provided a new and unsurpassed tool to track glyphosate and its degradation products in the environment by using naturally abundant isotopes in these compounds. Furthermore, this proxy allows distinguishing glyphosate-generated orthophosphate from other organophosphorus compounds in the environment. ☐ The abiotic degradation of glyphosate catalyzed by birnessite under aerobic and neutral pH conditions largely followed the glycine pathway generating glycine, formaldehyde, and orthophosphate. The other minor pathway was the AMPA pathway, forming AMPA and glyoxylic acid that ultimately degraded to form CO2, H2O, NH3, and orthophosphate. Sarcosine, the commonly recognized precursor to glycine, was not detected in any of the experiments performed despite its reasonably longer half-life (~13.6 h) than the sampling intervals. Preferential cleavage of the phosphonate adjacent C‒N bond to form glycine directly was also supported by the BCP analysis, which revealed that this C‒N bond was disproportionately affected by the interaction of glyphosate with Mn(IV). Overall, these…
Subjects/Keywords: Biological sciences;
Glyphosate;
Mechanisms;
Mn-oxides;
Pathways;
Source tracking
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APA ·
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APA (6th Edition):
Li, H. (2018). Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
. (Doctoral Dissertation). University of Delaware. Retrieved from http://udspace.udel.edu/handle/19716/23968
Chicago Manual of Style (16th Edition):
Li, Hui. “Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
.” 2018. Doctoral Dissertation, University of Delaware. Accessed December 14, 2019.
http://udspace.udel.edu/handle/19716/23968.
MLA Handbook (7th Edition):
Li, Hui. “Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
.” 2018. Web. 14 Dec 2019.
Vancouver:
Li H. Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
. [Internet] [Doctoral dissertation]. University of Delaware; 2018. [cited 2019 Dec 14].
Available from: http://udspace.udel.edu/handle/19716/23968.
Council of Science Editors:
Li H. Degradation of glyphosate by Mn-oxides: mechanisms, pathways, and source tracking
. [Doctoral Dissertation]. University of Delaware; 2018. Available from: http://udspace.udel.edu/handle/19716/23968
KTH
4.
Wen, Yingrong.
IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS.
Degree: Environmental Geochemistry and Ecotechnology, 2012, KTH
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109261
► Manganese (Mn) is an important element in soil, it occur natural in minerals and precipitated as Mn-oxides. Several factors could decide the solubility and…
(more)
▼ Manganese (Mn) is an important element in soil, it occur natural in minerals and precipitated as Mn-oxides. Several factors could decide the solubility and mobility of Mn in soil water. In this study, the impact of road de-icing salts (NaCl) on manganese mobilization and transport to groundwater in roadside soils has been investigated by leaching tests. Generally, in the salt solution leachates, the water-soluble concentrations of Mn tended to increase with elevated salt concentrations, suggesting that ion exchange mainly affected the mobilization. The process was also attributed to the complexion with Cl. Associated with exchangeable concentration of Mn and soil properties such as pH and acidity, the mobilizations of Mn varied. Mn-oxides can dissolve when reduced condition exists, therefore the oxalate extractable Mn was extracted to estimate the change of redox potential condition in roadside soils. The redox potential of soil samples is higher in general. Redox condition has little effect on the Mn solubility and mobility in this research. Although groundwater samples indicated that only a few periods and sites were under threaten of elevated concentrations of manganese, there is still great risk of transport of high water-soluble concentrations of Mn in roadside soils to groundwater, especially the areas exposed to de-icing salts. In addition, lower value of Mn concentrations in groundwater for considering good drinking water quality for the well-being of children should be paid more attention to.
Subjects/Keywords: Manganese; Mn-oxides; De-icing salts; Leaching test; Ion exchange; Groundwater
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APA ·
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APA (6th Edition):
Wen, Y. (2012). IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS. (Thesis). KTH. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109261
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):
Wen, Yingrong. “IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS.” 2012. Thesis, KTH. Accessed December 14, 2019.
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109261.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wen, Yingrong. “IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS.” 2012. Web. 14 Dec 2019.
Vancouver:
Wen Y. IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS. [Internet] [Thesis]. KTH; 2012. [cited 2019 Dec 14].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109261.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wen Y. IMPACTS OF ROAD DE-ICING SALTS ON MANGANESE TRANSPORT TO GROUNDWATER IN ROADSIDE SOILS. [Thesis]. KTH; 2012. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-109261
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Saskatchewan
5.
Choudhury, Sanjukta.
Spectroscopic study of transition metal compounds.
Degree: 2010, University of Saskatchewan
URL: http://hdl.handle.net/10388/etd-08212010-132458
► The electronic structure of some transition metal compounds, specifically, Ca-doped LaMnO₃, fundamental Mn oxides (MnO, Mn₂O₃, Mn₃O₄, and MnO₂), and Fe-doped ZnO is studied using…
(more)
▼ The electronic structure of some transition metal compounds, specifically, Ca-doped LaMnO₃, fundamental
Mn oxides (MnO, Mn₂O₃, Mn₃O₄, and MnO₂), and Fe-doped ZnO is studied using a combination of soft X-ray spectroscopy and atomic multiplet calculations. X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) are used as experimental tools to probe the unoccupied and occupied partial density of electronic states,respectively.
Ca-doped LaMnO₃ perovskites have attracted great attention due to their colossal magnetoresistance and a wide range of magnetic and structural transitions. The magnetic and charge transport properties of these perovskites are directly related with
Mn 3d-occupancy or
Mn-valency and therefore, an investigation of the
Mn-valence at Ca-doped LaMnO₃ system is important. In this system, the
Mn-valency is generally considered as a mixture of Mn³⁺ and Mn⁴⁺. But my research suggests the presence of Mn2+ at the surface of Ca-doped LaMnO₃ samples. It is observed that increasing Ca-doping decreases Mn2+ concentration, and conversely, increases Mn³⁺ concentration. High temperature annealing at 1000 °C in air leads to the full reduction of surface Mn2+. Mechanisms for these observations are proposed in this study.
Mn oxides (MnO, Mn₂O₃, Mn₃O₄, and MnO₂) are often used as reference standards for determining the
Mn-valency in
Mn-related complex systems and therefore a detailed understanding of their electronic structure is necessary. The
Mn L₂,₃ XAS and O K XAS are measured for the four
Mn oxides consisting of three common
Mn oxidation states (Mn2+ in MnO, Mn³⁺ in Mn₂O₃, mixture of Mn2+ and Mn³⁺ in Mn₃O₄, and Mn⁴⁺ in MnO₂). A significant energy shift with a systematic trend is observed in measured
Mn L₂,₃ and O K absorption edges. These energy shifts are identified as a characteristic shift for different
Mn oxidation states.
Mn L₂,₃ Resonant Inelastic X-ray Scattering (RIXS) spectroscopy is demonstrated as a powerful tool in describing low energy excitations, e.g. d-d excitations and charge-transfer excited states in
Mn oxides. For the first time, a RIXS study of Mn₂O₃, Mn₃O₄, and MnO₂ is accomplished. Atomic multiplet calculations are used to successfully reproduce the energy positions and intensity variations of d-d excitation peaks observed in the experiment, and thus to describe the experimental RIXS spectra.
Finally, the local electronic structure of Fe implanted ZnO samples, a useful diluted magnetic semiconductor for spintronics, is investigated to shed light on the existing debate about the origin of ferromagnetism in these materials. Fe L₂,₃ XAS reveals that doped Fe ions are present in both Fe²⁺ and Fe³⁺ valence states. A combined theoretical and experimental study shows that doped ions are incorporated into Zn-sites of ZnO in tetrahedral symmetry. Fe L3-RIXS measurements demonstrate that a high Fe-ion dose of 8 × 107 cm-2 causes formation of FeO clusters, while low dose samples exhibit more free carriers.
Advisors/Committee Members: Moewes, A., Chang, Gap Soo, Koustov, S., Mueller, J., McWilliams, K., Tse, J..
Subjects/Keywords: Mn oxides; Ca-doped LaMnO3; Atomic multiplet theory; X-ray absorption spectroscopy; Fe-implanted ZnO
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Manager
APA (6th Edition):
Choudhury, S. (2010). Spectroscopic study of transition metal compounds. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/etd-08212010-132458
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):
Choudhury, Sanjukta. “Spectroscopic study of transition metal compounds.” 2010. Thesis, University of Saskatchewan. Accessed December 14, 2019.
http://hdl.handle.net/10388/etd-08212010-132458.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Choudhury, Sanjukta. “Spectroscopic study of transition metal compounds.” 2010. Web. 14 Dec 2019.
Vancouver:
Choudhury S. Spectroscopic study of transition metal compounds. [Internet] [Thesis]. University of Saskatchewan; 2010. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10388/etd-08212010-132458.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Choudhury S. Spectroscopic study of transition metal compounds. [Thesis]. University of Saskatchewan; 2010. Available from: http://hdl.handle.net/10388/etd-08212010-132458
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
The Ohio State University
6.
Beak, Douglas Gerald.
Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces.
Degree: PhD, Soil Science, 2005, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1131933545
► The risk posed from incidental ingestion of arsenic-contaminated or lead-contaminated soil may depend on sorption of arsenate (As(V)) or lead (Pb(II)) to oxide surfaces in…
(more)
▼ The risk posed from incidental ingestion of
arsenic-contaminated or lead-contaminated soil may depend on
sorption of arsenate (As(V)) or lead (Pb(II)) to oxide surfaces in
soil. Arsenate or lead sorbed to ferrihydrite, corundum, and
birnessite model oxide minerals were used to simulate possible
effects of ingestion of soil contaminated with As(V) or Pb(II).
Arsenate or lead sorbed
oxides were placed in a simulated
gastrointestinal tract (in vitro) to ascertain the bioaccessibility
of As(V) or Pb(II) and changes in As(V) or Pb(II) surface
speciation. The speciation of As or Pb was determined using EXAFS
and XANES analysis. The As(V) adsorption maximum was found to be
7.04 g kg-1, and 0.47 g kg-1 for ferrihydrite and corundum,
respectively. The bioaccessible As(V) for ferrihydrite ranged form
0 to 5 % and for corundum ranged from 0 to 16 %. The surface
speciation for ferrihydrite and corundum was determined to be
binuclear bidentate. These results for As(V) sorbed to ferrihydrite
and corundum suggest that the bioaccessibility of As(V) is related
to the As(V) concentration, and the As(V) adsorption maximum. The
bioaccessibility of As(V) sorbed to birnessite ranged from 16 to 28
% and the As(V) surface speciation was binuclear bidentate. The
results for As (V) sorbed birnessite suggest that birnessite can
reduce the bioaccessibility of As(V) in contaminated soil. Sorption
of Pb(II) was significant for all the model
oxides used. The
sorption maximum was found to be 2.13 g kg-1 for corundum, 38.6 g
kg-1 for ferrihydrite, and 127 g kg-1 for birnessite. The
bioaccessible Pb(II) ranged from 53 to 88 % for ferrihydrite,
Pb(II) concentrations greater than 200 mg kg-1 was greater than 85
% for corundum and below 200 mg kg-1 there was no bioaccessible
Pb(II). There was no measurable bioaccessible Pb(II) for any
concentration of Pb sorbed birnessite. The surface Pb(II)
speciation was found to be: 1. Mononuclear bidentate for
ferrihydrite, 2. Mononuclear bidentate and an outer-sphere complex
for corundum, and 3. Binuclear bidentate, and trinuclear tridentate
for birnessite. Ferrihydrite and corundum usefulness in Pb
remediation would be limited when risk of incidental ingestion is
of major concern.
Advisors/Committee Members: Basta, Nicholas (Advisor).
Subjects/Keywords: Arsenic; Lead; bioaccessibility; bioavailability; Fe oxides; Al Oxides; Mn Oxides; Ferrihydrite; Corundum; Birnessite; As Speciation; Pb Speciation; EXAFS; XANES
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APA ·
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Manager
APA (6th Edition):
Beak, D. G. (2005). Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1131933545
Chicago Manual of Style (16th Edition):
Beak, Douglas Gerald. “Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces.” 2005. Doctoral Dissertation, The Ohio State University. Accessed December 14, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1131933545.
MLA Handbook (7th Edition):
Beak, Douglas Gerald. “Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces.” 2005. Web. 14 Dec 2019.
Vancouver:
Beak DG. Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces. [Internet] [Doctoral dissertation]. The Ohio State University; 2005. [cited 2019 Dec 14].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1131933545.
Council of Science Editors:
Beak DG. Lead and arsenic speciation and bioaccessibility following
sorption on oxide mineral surfaces. [Doctoral Dissertation]. The Ohio State University; 2005. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1131933545
University of St. Andrews
7.
Gibbs, Alexandra S.
Emergent states in transition metal oxides
.
Degree: 2013, University of St. Andrews
URL: http://hdl.handle.net/10023/3557
► Transition metal oxides adopt a wide variety of crystal structures and display a diverse range of physical phenomena from Mott insulating states to electron-nematics to…
(more)
▼ Transition metal
oxides adopt a wide variety of crystal structures and display a diverse range of physical phenomena from Mott insulating states to electron-nematics to unconventional superconductivity. Detailed understanding of these states and how they may be manipulated by structural modifications requires both precise structural knowledge and in-depth physical property measurements using as many techniques over as wide a range of phase space as possible. In the work described in this thesis a range of transition metal
oxides were studied using high-resolution powder neutron diffraction and detailed low-temperature physical property measurements. The quaternary barium orthotellurates Ba₂NiTeO₆, Ba₂CuTeO₆ and Ba₂ZnTeO₆ belong to an almost unstudied family of materials. The development of procedures for synthesizing large single crystals has facilitated the investigation of interesting new anisotropic magnetic states in the Cu and Ni systems and the existence of a possible structural phase transition in the Zn-based compound. YMnO₃ is a multiferroic with improper ferrielectricity. The study of the high-temperature structural phases described in this thesis has led to the identification both of the transition path to the ferrielectric state and the identification of an isostructural phase transition within the ferrielectric phase. BiFe₀.₇Mn₀.₃O₃ is also a multiferroic material but with proper ferroelectricity. The investigation of the structural phases of this compound have provided confirmation of the high-temperature phases with the reassignment of the symmetry of the highest-temperature phase which is intriguingly different to that of the unsubstituted material. Finally, an investigation of the electronic structures of the high conductivity delafossites PdCoO₂ and PdCrO₂ using micro-cantilever torque magnetometry measurements of quantum oscillations is described. This has resolved the warping of the Fermi surface of PdCoO₂ and given insights into the complicated Fermi surface of the itinerant antiferromagnet PdCrO₂.
Advisors/Committee Members: Mackenzie, Andrew (advisor), Lightfoot, Philip (advisor).
Subjects/Keywords: Transition metal oxides;
Neutron diffraction;
Quantum oscillations;
Multiferroics;
Condensed matter;
Crystal growth;
Phase transitions;
Ba₂NiTeO₆;
Ba₂CuTeO₆;
Ba₂ZnTeO₆;
YMnO₃;
BiFe₀.₇Mn₀.₃O₃;
PdCoO₂;
PdCrO₂
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APA (6th Edition):
Gibbs, A. S. (2013). Emergent states in transition metal oxides
. (Thesis). University of St. Andrews. Retrieved from http://hdl.handle.net/10023/3557
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):
Gibbs, Alexandra S. “Emergent states in transition metal oxides
.” 2013. Thesis, University of St. Andrews. Accessed December 14, 2019.
http://hdl.handle.net/10023/3557.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gibbs, Alexandra S. “Emergent states in transition metal oxides
.” 2013. Web. 14 Dec 2019.
Vancouver:
Gibbs AS. Emergent states in transition metal oxides
. [Internet] [Thesis]. University of St. Andrews; 2013. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10023/3557.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gibbs AS. Emergent states in transition metal oxides
. [Thesis]. University of St. Andrews; 2013. Available from: http://hdl.handle.net/10023/3557
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Helsinki
8.
Dia, Nay.
The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status.
Degree: Department of Food and Environmental Sciences; Helsingfors universitet, Agrikultur- och forstvetenskapliga fakulteten, Institutionen för livsmedels- och miljövetenskaper, 2016, University of Helsinki
URL: http://hdl.handle.net/10138/160197
► The interactions between sediment chemistry and bacterial communities are multidirectional and complex. A hypoxia-driven decrease in dissolved oxygen (O2) leads to changes in sediment chemistry,…
(more)
▼ The interactions between sediment chemistry and bacterial communities are multidirectional and complex. A hypoxia-driven decrease in dissolved oxygen (O2) leads to changes in sediment chemistry, bacterial community and ultimately alters their interactions. The sediment components very sensitive to changes in O2 are iron (Fe) and manganese (Mn) oxides. When O2 content decreases, they will be reduced by bacteria in order to obtain energy.
This study was carried out with sediment samples collected from sites of different oxygen status in the Gulf of Finland. The focus was to unravel the interactions between sediment chemistry and bacterial communities by means of chemical extractions distinguishing between Fe and Mn pools of different solubility and, thus, bioavailability. For this purpose, a two-step chemical extraction was carried out in order to selectively quantify the easily reducible and more crystalline fractions of Fe and Mn oxides. The chemistry of phosphorus (P) is intrinsically linked to Fe and aluminum (Al) oxides but not to Mn oxides which are not able to retain P. Unlike Fe and Mn, Al is not a redox-sensitive element but its oxides are of importance in controlling the release of P from sediments by resorption of P. The extracts were analyzed for Fe, Mn, Al and P. Furthermore, a next generation high-input method was used to extract the DNA from the sediments. The results of the chemical extractions and taxonomical classification of the bacteria were statistically analyzed. Subsequently, the interactions between the easily-reducible fractions of Fe and Mn oxides and bacterial communities were established using correlations (correlation coefficient ≥ 0.7). The extractability of Fe and Mn increased in poorly-oxygenated and hypoxic conditions. Iron seemed to originate in the easily-reducible fraction, while Mn was in a less reactive form than Fe. As expected, the extractability of Al did not vary with changing oxygen status. In addition, the rather low extractability of P suggests a strong initial adsorption of P on Al oxides. In environment low in oxygen, P released from the Fe oxides was resorbed by Al oxides.
We conclude that the major bacterial processes in the sediments are related to the reduction of sulfate and sulfur and decomposition of organic matter. The bacterial communities varied both vertically and horizontally. The vertical variation was mainly explained by the redox potential, while the horizontal variation was more complex and essentially related to easily-reducible Fe and total carbon and nitrogen in sediment. The correlations between the easily-reducible Fe and Mn and the bacterial communities revealed taxa that reduce Fe and/or Mn, some that oxidize metals, and others that could benefit from organic rich environments created by Fe, Mn and S-reducing bacteria. The correlations indicate causative relationships and indirect associations, which can provide leads for future research.
Subjects/Keywords: anaerobic iron and manganese reduction; bacterial communities; biogeochemical interactions; chemical extraction; easily reducible Fe and Mn oxides; hypoxia; Mark- och miljövetenskap; Environmental Soil Science; Maaperä- ja ympäristötiede
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APA (6th Edition):
Dia, N. (2016). The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status. (Masters Thesis). University of Helsinki. Retrieved from http://hdl.handle.net/10138/160197
Chicago Manual of Style (16th Edition):
Dia, Nay. “The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status.” 2016. Masters Thesis, University of Helsinki. Accessed December 14, 2019.
http://hdl.handle.net/10138/160197.
MLA Handbook (7th Edition):
Dia, Nay. “The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status.” 2016. Web. 14 Dec 2019.
Vancouver:
Dia N. The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status. [Internet] [Masters thesis]. University of Helsinki; 2016. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10138/160197.
Council of Science Editors:
Dia N. The chemical properties and microbial communities of Gulf of Finland sediments differing in their oxygen status. [Masters Thesis]. University of Helsinki; 2016. Available from: http://hdl.handle.net/10138/160197
9.
Barrett, Heather A.
A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE.
Degree: MS, Geology & Environmental Earth Science, 2013, Miami University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=miami1375787636
► Cryptomelane is a Mn-oxide of great environmental importance that occurs in low temperature and other geologic environments. Cryptomelane is of great interest because of its…
(more)
▼ Cryptomelane is a
Mn-oxide of great environmental
importance that occurs in low temperature and other geologic
environments. Cryptomelane is of great interest because of its
cation exchange capacity and catalytic properties in synthetic
form. This investigation is the first detailed transmission
electron microscopy study to focus specifically on microtexture and
defects and to involve scanning transmission electron microscopy
(STEM). Four samples of cryptomelane (a natural sample from the
Xiangtan manganese deposit in China, a synthetic produced by an
aqueous route, a Zn-doped synthetic, and a battery derived
synthetic) have been investigated and compared. This study
indicates that although in general cryptomelane has defects and
textures that are common amongst multiple samples, there are
differences that are a function of composition and origin and these
defects impact application performance. The results provide
structure for future comparative interdisciplinary study that may
enable production of a new material group useful for reducing
pollution in several settings.
Advisors/Committee Members: KREKELER, MARK (Advisor).
Subjects/Keywords: Environmental Geology; Environmental Science; Geology; electron microscopy, TEM, cryptomelane, Mn-oxides,
battery, recycling
…dominant
form in which Mn occurs is in oxide minerals. Common Mn-oxides are birnessite
(… …x28;Ca, Mn) CO3) and
rhodochrosite (MnCO3). These oxides occur in near… …and carbonate mineral weathering, which
often contain minor amounts of Mn. Manganese oxides… …percentage of the bulk chemical
composition such as 0.1 weight percent. Mn-oxides are known for… …minerals that have manganese as a
major cation (Post, 1999). Mn-oxides are commonly…
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APA (6th Edition):
Barrett, H. A. (2013). A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE. (Masters Thesis). Miami University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=miami1375787636
Chicago Manual of Style (16th Edition):
Barrett, Heather A. “A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE.” 2013. Masters Thesis, Miami University. Accessed December 14, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=miami1375787636.
MLA Handbook (7th Edition):
Barrett, Heather A. “A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE.” 2013. Web. 14 Dec 2019.
Vancouver:
Barrett HA. A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE. [Internet] [Masters thesis]. Miami University; 2013. [cited 2019 Dec 14].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=miami1375787636.
Council of Science Editors:
Barrett HA. A COMPARATIVE TRANSMISSION ELECTRON MICROSCOPY INVESTIGATION
OF DEFECTS AND TEXTURES IN CRYPTOMELANE. [Masters Thesis]. Miami University; 2013. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=miami1375787636
10.
折井, 亮子.
La1-xSrxMnO3-δ薄膜の電界効果.
Degree: Japan Advanced Institute of Science and Technology / 北陸先端科学技術大学院大学
URL: http://hdl.handle.net/10119/2898
Supervisor:今井 捷三 教授
材料科学研究科
修士
Subjects/Keywords: La1-xSrxMnO3-δ,電界効果,Mn酸化物,二重交換相互作用; La1-xSrxMnO3-δ, field effect manganese oxides, dou
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APA (6th Edition):
折井, . (n.d.). La1-xSrxMnO3-δ薄膜の電界効果. (Thesis). Japan Advanced Institute of Science and Technology / 北陸先端科学技術大学院大学. Retrieved from http://hdl.handle.net/10119/2898
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
折井, 亮子. “La1-xSrxMnO3-δ薄膜の電界効果.” Thesis, Japan Advanced Institute of Science and Technology / 北陸先端科学技術大学院大学. Accessed December 14, 2019.
http://hdl.handle.net/10119/2898.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
折井, 亮子. “La1-xSrxMnO3-δ薄膜の電界効果.” Web. 14 Dec 2019.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Vancouver:
折井 . La1-xSrxMnO3-δ薄膜の電界効果. [Internet] [Thesis]. Japan Advanced Institute of Science and Technology / 北陸先端科学技術大学院大学; [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10119/2898.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
Council of Science Editors:
折井 . La1-xSrxMnO3-δ薄膜の電界効果. [Thesis]. Japan Advanced Institute of Science and Technology / 北陸先端科学技術大学院大学; Available from: http://hdl.handle.net/10119/2898
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
Indian Institute of Science
11.
Pal, Banabir.
Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems.
Degree: 2016, Indian Institute of Science
URL: http://hdl.handle.net/2005/2970
► Transition metal oxides and chalcogenides are an ideal platform for demonstrating and investigating many interesting electronic phases of matter. These phases emerge as a result…
(more)
▼ Transition metal
oxides and chalcogenides are an ideal platform for demonstrating and investigating many interesting electronic phases of matter. These phases emerge as a result of collective many body interactions among the electrons. The omnipresent electron, depending on its interaction with other electrons and with the underlying lattice, can generate diverse phases of matter with exotic physical properties. The ultimate objective of Materials Science is to provide a complete microscopic understanding of these myriad electronic phases of matter. A proper understanding of the collective quant-tum behaviour of electrons in different system can also help in designing and tuning new electronic phases of matter that may have strong impact in the field of microelectronics, well beyond that predicted by Moore s law.
Strong electron correlation effects produce a wide spectrum of ground state prop-retires like superconductivity, Metal Insulator Transition (MIT), charge-orbital ordering and many more. Similarly, different spin interactions among electrons, essentially due to various kinds of exchange coupling, give rise to varying magnetic ground state prop-retires like ferromagnetism, anti-ferromagnetism, spin glass, among others. The main objective of this thesis is to understand and rationalize diverse electronic and magnetic phases of matter in some selected strongly correlated systems.
In chapter 1 we have provided an overview of various electronic and magnetic phases of matter which are relevant and necessary for understanding the chapters that follow. The first part of this chapter describes the fundamental concepts of the so called Metal Insulator Transition (MIT). A small section is dedicated to the subtle interactions among electrons and lattice that actually drive a system from a highly conducting metallic state to a strongly resistive insulating state. The second part of this chapter offers a compilation of different magnetic ground states which are discussed in detail in the last two chapters.
In Chapter 2, we have explained various methodologies and experimental tech-antiques that have been used in the work reported in this thesis.
In Chapter 3, we have provided a detailed understanding of the MIT in different polymorphic forms of Vanadium dioxide (VO2). Although VO2 exhibits a number of polymorphic forms, only the rutile/monoclinic VO2 phase has been studied extensively compared to other polymorphic forms. This phase shows a well-established MIT across ∼340 K, which has been extensively investigated in order to understand the relative importance of many body electron correlation effects arising primarily from on-site Coulomb interactions within the Vanadium 3d manifold, and single electron effects flounced by the dimerization of Vanadium atoms. Unlike the rutile phase of VO2, little is known about the MIT appearing across 212 K in the metastable B-phase of VO2. This phase shows dimerization of only half of the Vanadium atoms in the insulating state, in contrast to rutile/monoclinic VO2, which show…
Advisors/Committee Members: Sarma, D D.
Subjects/Keywords: Metal Insulator Transition (MIT); Transition Metal Oxides; Strongly Correlated Electron Systems; Strongly Correlated Systems-Electronic Structure; Strongly Correlated Systems-Magnetic Structure; Condensed Matter Physics; Matter-Electronic Phase; Metals and Insulators; Strongly Correlated Materials; TiO3-SrTiO3 Heterostructure; MoS2; Vanadium Dioxide (VO2); Sr2FeMoO6; Mn doped SrTiO3; Solid State and Structural Chemistry
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APA ·
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Manager
APA (6th Edition):
Pal, B. (2016). Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems. (Thesis). Indian Institute of Science. Retrieved from http://hdl.handle.net/2005/2970
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):
Pal, Banabir. “Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems.” 2016. Thesis, Indian Institute of Science. Accessed December 14, 2019.
http://hdl.handle.net/2005/2970.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pal, Banabir. “Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems.” 2016. Web. 14 Dec 2019.
Vancouver:
Pal B. Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems. [Internet] [Thesis]. Indian Institute of Science; 2016. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/2005/2970.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pal B. Electronic and Magnetic Structures of Some Selected Strongly Correlated Systems. [Thesis]. Indian Institute of Science; 2016. Available from: http://hdl.handle.net/2005/2970
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Georgia Tech
12.
Zhang, Huichun.
Metal oxide-facilitated oxidation of antibacterial agents.
Degree: PhD, Civil and Environmental Engineering, 2004, Georgia Tech
URL: http://hdl.handle.net/1853/5027
► Metal oxide-facilitated transformation is likely an important degradation pathway of antibacterial agents at soil-water interfaces. Phenolic disinfectants (triclosan and chlorophene), fluoroquinolones (FQs), and aromatic N-oxides…
(more)
▼ Metal oxide-facilitated transformation is likely an important degradation pathway of antibacterial agents at soil-water interfaces. Phenolic disinfectants (triclosan and chlorophene), fluoroquinolones (FQs), and aromatic N-
oxides are of particular concern due to their widespread usage, potential toxicity and frequent detection in the environment. Results of the present study show that the above antibacterial agents are highly susceptible to metal oxide-facilitated oxidation.
The interfacial reactions exhibit complex reaction kinetics, which are affected by solution pH, the presence of co-solutes, surface properties of metal
oxides, and structural characteristics of antibacterial agents. Adsorption of the antibacterial agents to
Mn and Fe oxide surfaces generally proceeds faster than oxidation reactions of these compounds by
Mn and Fe
oxides, especially in the case of Fe
oxides.
Reaction intermediates and end products are identified by GC/MS, LC/MS and/or FTIR. Structurally-related model compounds are examined to facilitate reaction site and mechanism elucidation. On the basis of experimental results and literature, reaction schemes are proposed. In general, the antibacterial agent is adsorbed to the oxide surface, forming a precursor complex. Electrons are transferred within the precursor complex from the antibacterial agent to the oxide, followed by releasing of the radical intermediates which undergo further reactions to generate oxidation products. The precursor complex formation and electron transfer are likely rate-limiting.
For triclosan, phenoxy radicals are critical intermediates to form oxidation products through three pathways (i.e., radical coupling, further oxidation of the radical, and breakdown of an ether bond within the radical). The first two pathways are also operative in the oxidation of chlorophene. For FQs, oxidation generates radical intermediates that are most likely centered on the inner N in the piperazine ring. The radical intermediates then undergo three major pathways (i.e., radical coupling, N-dealkylation, and hydroxylation) to yield a variety of products. For aromatic N-
oxides, a N-oxide radical intermediate is generated upon oxidation by MnO2, followed by the loss of oxygen from the N-oxide moiety and the formation of a hydroxyl group at the C-atom adjacent to the N-oxide moiety.
Overall, a fundamental understanding of the reaction mechanisms between three classes of antibacterial agents and metal
oxides has been obtained.
Advisors/Committee Members: Huang, Ching-Hua (Committee Chair), Mulholland, James (Committee Member), Pavlostathis, Spyros (Committee Member), Wine, Paul (Committee Member), Yiacoumi, Sotira (Committee Member).
Subjects/Keywords: Reaction mechanisms; Kinetics; Oxidation; Antibacterial agents; Fe oxide; Mn oxide; Aromatic N-oxides; Fluoroquinolones; Chlorophene; Triclosan; Reaction mechanisms (Chemistry); Oxidation; Metallic oxides; Manganese oxide; Ferrous oxide; Antibacterial agents
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APA (6th Edition):
Zhang, H. (2004). Metal oxide-facilitated oxidation of antibacterial agents. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/5027
Chicago Manual of Style (16th Edition):
Zhang, Huichun. “Metal oxide-facilitated oxidation of antibacterial agents.” 2004. Doctoral Dissertation, Georgia Tech. Accessed December 14, 2019.
http://hdl.handle.net/1853/5027.
MLA Handbook (7th Edition):
Zhang, Huichun. “Metal oxide-facilitated oxidation of antibacterial agents.” 2004. Web. 14 Dec 2019.
Vancouver:
Zhang H. Metal oxide-facilitated oxidation of antibacterial agents. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/1853/5027.
Council of Science Editors:
Zhang H. Metal oxide-facilitated oxidation of antibacterial agents. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/5027
13.
Kapetanakis, Myron.
Dynamic electronic and optical properties of magnetic semiconductors.
Degree: 2007, University of Crete (UOC); Πανεπιστήμιο Κρήτης
URL: http://hdl.handle.net/10442/hedi/20308
► Παρουσιάζουμε τη μελέτη των μαγνητικών ιδιοτήτων διαφόρων σιδηρομαγνητικών υλικών. Χρησιμοποιώντας τη θεωρία μεταβολών μελετάμε το φάσμα των διεγερμένων καταστάσεων των κυμάτων spin. Επίσης μια εφαρμογή…
(more)
▼ Παρουσιάζουμε τη μελέτη των μαγνητικών ιδιοτήτων διαφόρων σιδηρομαγνητικών υλικών. Χρησιμοποιώντας τη θεωρία μεταβολών μελετάμε το φάσμα των διεγερμένων καταστάσεων των κυμάτων spin. Επίσης μια εφαρμογή της μεθόδου των συναρτήσεων green μας επιτρέπει να μελετήσουμε το χρόνο ζωής των κυμάτων spin και τη δυναμική τους στους μαγνητικούς ημιαγωγούς ΙΙΙ-V. Η μέθοδος μας αναπαράγει την προσέγγιση τυχαίων φάσεων (RPA) , το ανάπτυγμα 1/S και τα αποτελέσματα μέσου πεδίου. Ο σκοπός αυτής της διατριβής είναι η μελέτη των συσχετίσεων πολλών σωμάτων στο φάσμα και στο χρόνο ζωής των κυμάτων spin. Τέτοια φαινόμενα εισάγονται από τη σκέδαση ενός ζεύγους ηλεκτρονίου – οπής από ένα μαγνόνιο. Βρίσκουμε ότι οι συσχετίσεις επιδρούν σημαντικά στη διασπορά των μανγκατιτών και αυξάνουν τη σχετικότητα με το πείραμα. Επιπλέον βρίσκουμε μια ισχυρή αύξηση στο stiffness, άρα και στο Tc, στους DMS. Τελικά οι συσχετίσεις επιδρούν ισχυρά στο χρόνο ζωής των κυμάτων spin αφού εισαγάγουν μια μη γραμμική συμπεριφορά του συντελεστή Gilbert ως προς την πυκνότητα των οπών η οποία είναι απούσα στην προσέγγιση μέσου πεδίου.
Subjects/Keywords: Κύματα σπιν; Μαγνόνια; Μαγγαμίτες, οξείδια του Μαγγανίου; III (Mn) V μαγνητικοί ημιαγωγοί; Συντελεστής Gilbert; Θεωρία μεταβολών; Μέθοδος συναρτήσεων Green; Spin - waves; Magnons; Manganites, manganese oxides; III (Mn) V magnetic semiconductors; Zone boundary softening; Gilbert damping coefficient; Variational method; Green's function
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APA (6th Edition):
Kapetanakis, M. (2007). Dynamic electronic and optical properties of magnetic semiconductors. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/20308
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):
Kapetanakis, Myron. “Dynamic electronic and optical properties of magnetic semiconductors.” 2007. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed December 14, 2019.
http://hdl.handle.net/10442/hedi/20308.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kapetanakis, Myron. “Dynamic electronic and optical properties of magnetic semiconductors.” 2007. Web. 14 Dec 2019.
Vancouver:
Kapetanakis M. Dynamic electronic and optical properties of magnetic semiconductors. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2007. [cited 2019 Dec 14].
Available from: http://hdl.handle.net/10442/hedi/20308.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kapetanakis M. Dynamic electronic and optical properties of magnetic semiconductors. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2007. Available from: http://hdl.handle.net/10442/hedi/20308
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
. 
Open Access Theses and Dissertations
