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You searched for subject:(Contaminant mitigation). Showing records 1 – 3 of 3 total matches.

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1. Du, Ran. A Quantitative Approach to Military Water System Vulnerability Assessments.

Degree: 2014, Johns Hopkins University

The Department of the Army routinely conducts water system vulnerability assessment (WSVA) on military water distribution systems (WDS). Risk assessors construct attack scenarios and then estimate the risks using their expert judgment. These risk assessments are traditionally difficult to support with evidence and historical data. As a result, decision makers often question the validity of the assessor findings and their recommendations. The goal of this research paper is to improve the WSVA program by presenting decision makers with quantifiable risk. I propose a hybrid risk analysis based on hydraulic modeling and probabilistic risk analysis. This improved methodology (WSVA2) presents a quantitative approach to risk assessment and uses simulations to support the assessor’s expert judgment. A fictitious military WDS and its data are created to avoid disclosure of sensitive information. Hydraulic simulation models are used to assess the consequences of a successful contamination attack and to evaluate the outcome of a catastrophic scenario. Three unknowns of the scenarios are the contaminant toxicity, contaminant reaction rate in water and contaminant quantity used in the attack. Attack simulations are randomly generated using distribution curves based on both known studies and assumptions. Monte Carlo simulations are used to quantify the uncertainties of the model. Findings show that 53,126 Exposure Incidents (EI) resulted from the contamination attack on Water Tower 1. In the catastrophic scenario, over 400,000 EI occurred in 1 week which affected over 4,000 people in the Hexagon Building. And in an attack-response scenario, hydraulic modeling is used to demonstrate that the current Emergency Response Plan (ERP) cannot sufficiently mitigate the contamination threat below Military Exposure Guideline (MEG) level. Advisors/Committee Members: Guikema, Seth (advisor).

Subjects/Keywords: military; water distribution system; risk analysis; expert judgment; simulations; catastrophic; contaminant; monte carlo; hydraulic modeling; exposure; multi attribute utility theory; emergency response plan; mitigation; military exposure guideline

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Du, R. (2014). A Quantitative Approach to Military Water System Vulnerability Assessments. (Thesis). Johns Hopkins University. Retrieved from http://jhir.library.jhu.edu/handle/1774.2/37119

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, Ran. “A Quantitative Approach to Military Water System Vulnerability Assessments.” 2014. Thesis, Johns Hopkins University. Accessed January 21, 2020. http://jhir.library.jhu.edu/handle/1774.2/37119.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Du, Ran. “A Quantitative Approach to Military Water System Vulnerability Assessments.” 2014. Web. 21 Jan 2020.

Vancouver:

Du R. A Quantitative Approach to Military Water System Vulnerability Assessments. [Internet] [Thesis]. Johns Hopkins University; 2014. [cited 2020 Jan 21]. Available from: http://jhir.library.jhu.edu/handle/1774.2/37119.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Du R. A Quantitative Approach to Military Water System Vulnerability Assessments. [Thesis]. Johns Hopkins University; 2014. Available from: http://jhir.library.jhu.edu/handle/1774.2/37119

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Meng, Lingjun. Modeling contaminant spread and mitigation in the indoor environment.

Degree: PhD, 0133, 2014, University of Illinois – Urbana-Champaign

Experimental and modeling efforts, using a pilot-scale testbed and multizone modeling, are undertaken to develop filtration and ventilation strategies aimed at improving indoor air quality (IAQ). As part of this effort, a model is developed to effectively estimate crack areas of the multizone testbed. The model is divided into two sub-approaches: one approach is to assume the same crack area for the same type of opening and determine them by minimizing the sum of the squares of relative error between the calculated and experimental ventilation rates for the whole facility; the other is to assume that the crack areas are independent of each other and a similar least-squares minimization is applied to determine these crack areas zone by zone. A comparison of the two approaches shows that both can provide satisfactory results, and the latter approach is preferred, because it provides more flexibility and detail. Ventilation systems are explored using multizone simulations. The model results suggest a distributed unbalanced ventilation system is preferred for maintaining IAQ, because 1) it can provide positive pressure difference across the building envelope to prevent exterior contaminant infiltration; and 2) some contaminated indoor zones can be “isolated” from adjacent ones by adjusting the relative pressure differences. Realistic particle distributions typical to a particular contamination threat of interest are considered, and an acoustically enhanced impaction (AEI) filtration device is investigated together with other filters. The protection factor (PF, a ratio of concentration integrated over time in the ambient to that indoors) is chosen as a performance metric. A PF-oriented evaluation framework has been established such that ventilation system/strategy (or filter) comparison in terms of IAQ enhancement is straightforward. For instance, 16 filtration schemes are compared to identify preferred ventilation and filtration strategies. For the indoor environment, a highly efficient outside air (OA) filter is recommended, but a recirculated air (RA) filter is relatively much less effective. For vestibule protection, a stand-alone balanced system with 100% RA filtration is recommended. The AEI device can be an alternative to a HEPA filter when the ambient contamination level is low to moderate. Extension of an existing analytical steady-state PF model is undertaken to demonstrate the advantages of pressurization protection of buildings over non-pressurization protection. The analytical PF model can be used to determine the ventilation flow rate and filter efficiency at a specific PF level and guide the vestibule door operation. It is found that the minimum closing period of the vestibule interior door typically should be 20 minutes to protect the room. Advisors/Committee Members: Jacobi, Anthony M. (advisor), Jacobi, Anthony M. (Committee Chair), Bullard, Clark W. (committee member), Hrnjak, Predrag S. (committee member), Wang, Xinlei (committee member).

Subjects/Keywords: Indoor Air Quality; Contaminant mitigation; Pressurization protection; Crack estimation; Protection factor; CONTAM

…validity and reliability of CONTAM (ASHRAE, 2009). 1.2.2 Contaminant Mitigation In… …cracks) (2.8b) In the current study, the focus is contaminant mitigation in a… …27 Table 3.1 Contaminant properties… …100 Table D.2 Contaminant properties for Cases 1-2… …contaminant concentration (mg/m3 or #/cm3) ci contaminant concentration in the indoor… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Meng, L. (2014). Modeling contaminant spread and mitigation in the indoor environment. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/49619

Chicago Manual of Style (16th Edition):

Meng, Lingjun. “Modeling contaminant spread and mitigation in the indoor environment.” 2014. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 21, 2020. http://hdl.handle.net/2142/49619.

MLA Handbook (7th Edition):

Meng, Lingjun. “Modeling contaminant spread and mitigation in the indoor environment.” 2014. Web. 21 Jan 2020.

Vancouver:

Meng L. Modeling contaminant spread and mitigation in the indoor environment. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2014. [cited 2020 Jan 21]. Available from: http://hdl.handle.net/2142/49619.

Council of Science Editors:

Meng L. Modeling contaminant spread and mitigation in the indoor environment. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2014. Available from: http://hdl.handle.net/2142/49619

3. Zhang, Andi. Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers.

Degree: PhD, Civil and Environmental Engineering, 2013, Georgia Tech

Of all the strategies to reduce carbon emissions, carbon dioxide (CO₂) geological sequestration is an immediately available option for removing large amounts of the gas from the atmosphere. However, our understanding of the transition behavior between Forchheimer and Darcy flow through porous media during CO₂ injection is currently very limited. In addition, the kinetic mass transfer of SO₂ and CO₂ from CO₂ stream to the saline and the fully coupling between the changes of porosity and permeability and multiphase flow are two significant dimensions to investigate the brine acidification and the induced porosity and permeability changes due to SO₂ co-injection with CO₂. Therefore, this dissertation develops a multiphase flow, contaminant transport and geochemical model which includes the kinetic mass transfer of SO₂ into deep saline aquifers and obtains the critical Forchheimer number for both water and CO₂ by using the experimental data in the literature. The critical Forchheimer numbers and the multiphase flow model are first applied to analyze the application problem involving the injection of CO₂ into deep saline aquifers. The results show that the Forchheimer effect would result in higher displacement efficiency with a magnitude of more than 50% in the Forchheimer regime than that for Darcy flow, which could increase the storage capacity for the same injection rate and volume of a site. Another merit for the incorporation of Forchheimer effect is that more CO₂ would be accumulated in the lower half of the domain and lower pressure would be imposed on the lower boundary of the cap-rock. However, as a price for the advantages mentioned above, the injection pressure required in Forchheimer flow would be higher than that for Darcy flow. The fluid flow and contaminant transport and geochemical model is then applied to analyze the brine acidification and induced porosity and permeability changes due to SO₂ co-injection. The results show that the co-injection of SO₂ with CO₂ would lead to a substantially acid zone near the injecting well and it is important to include the kinetic dissolution of SO₂ from the CO₂ stream to the water phase into the simulation models, otherwise considerable errors would be introduced for the equilibrium assumption. This study provides a useful tool for future analysis and comprehension of multiphase Darcy-Forchheimer flow and brine acidification of CO₂ injection into deep saline aquifers. Results from this dissertation have practical use for scientists and engineers concerned with the description of flow behavior, and transport and fate of SO₂ during SO₂ co-injection with CO₂ in deep saline aquifers. Advisors/Committee Members: Aral, Mustafa M. (advisor), Stieglitz, Marc (committee member), Luo, Jian (committee member), Guan, Jiabao (committee member), Stieglitz, Marc (committee member), Luo, Jian (committee member), Uzer, Turgay (committee member).

Subjects/Keywords: Darcy-Forchheimer flow; Multiphase flow; Critical Forchheimer number; Deep saline aquifers; Contaminant transport; CO₂ sequestration; SO₂ co-injection; Darcy's law; Aquifers; Saline waters; Carbon dioxide; Carbon dioxide Environmental aspects; Carbon dioxide mitigation; Carbon sequestration; Geochemistry

…65 Table 4.2 Parameters for the fluid flow and contaminant transport… …84 Table 5.1 Parameters for fluid flow and contaminant transport… …contaminant transport and geochemistry with the coupling between the changes of porosity and… …contaminant transport and geochemical model which incorporates the kinetic mass transfer of SO2 and… …governing equations for multiphase contaminant transport and the geochemical model are developed… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zhang, A. (2013). Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/49065

Chicago Manual of Style (16th Edition):

Zhang, Andi. “Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers.” 2013. Doctoral Dissertation, Georgia Tech. Accessed January 21, 2020. http://hdl.handle.net/1853/49065.

MLA Handbook (7th Edition):

Zhang, Andi. “Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers.” 2013. Web. 21 Jan 2020.

Vancouver:

Zhang A. Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2020 Jan 21]. Available from: http://hdl.handle.net/1853/49065.

Council of Science Editors:

Zhang A. Numerical investigation of multiphase Darcy-Forchheimer flow and contaminant transport during SO₂ co-injection with CO₂ in deep saline aquifers. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/49065

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