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You searched for +publisher:"University of Colorado" +contributor:("Louis Stodieck"). Showing records 1 – 3 of 3 total matches.

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University of Colorado

1. Mindock, Jennifer. Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis.

Degree: PhD, Aerospace Engineering Sciences, 2012, University of Colorado

The ability of crewmembers to perform various critical functions during spacecraft operations is widely recognized as being essential to mission success. This necessity motivates the desire to better characterize factors that can influence crewmember performance so that those with positive effects can be enhanced, while those with negative impacts can be minimized. Established Human Reliability Analysis methods exist for analyzing performance within the context of myriad terrestrial scenarios. Many of the existing methods have their roots in nuclear power plant operations. While perhaps similar, the factors influencing performance traditionally used in these methods do not take into account the unique conditions encountered during spaceflight. Therefore, this research has identified a tailored set of factors that influence human task performance during space missions. This thesis describes an organizational scheme developed to aid in classifying and communicating the factors across disciplines and organizations. Definitions of identified factors are given for the spaceflight-specific context. A visual display of the factors, called the Contributing Factor Map, is presented and its use as a risk communication tool is discussed. The Bayesian Network is discussed as a quantification approach allowing relationships between factors, in addition to the factor relationships to performance outcomes, to be modeled. A method for determining a network structure was developed for domains such as human spaceflight, in which a global set of data for analysis is not available. This method applied the Analytic Hierarchy Process, and causal latency concepts from the Human Factors Analysis and Classification System in a novel way to guide choices for modeling the dominant set of factors and relationships in a simplified Bayesian Network structure. In addition, an approach for modeling the factors as statistical variables in a Bayesian Network making use of existing design requirements and human performance data is discussed. Applications of this modeling approach in terms of requirement completeness assessment and identification of future research needs are also described. Finally, an illustrative quantified Bayesian Network for the spaceflight domain is given, built on the factor identification and structure development work throughout the thesis. Its use in a Human Reliability Analysis is demonstrated. Advisors/Committee Members: David M. Klaus, Alireza Doostan, Louis Stodieck, Peter Polson, Richard Heydorn.

Subjects/Keywords: Analytic Hierarchy Process; Bayesian Network; Human Reliability Analysis; Performance Influencing Factors; Performance Shaping Factors; Spaceflight; Aerospace Engineering; Engineering

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APA (6th Edition):

Mindock, J. (2012). Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis. (Doctoral Dissertation). University of Colorado. Retrieved from http://scholar.colorado.edu/asen_gradetds/47

Chicago Manual of Style (16th Edition):

Mindock, Jennifer. “Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis.” 2012. Doctoral Dissertation, University of Colorado. Accessed December 07, 2019. http://scholar.colorado.edu/asen_gradetds/47.

MLA Handbook (7th Edition):

Mindock, Jennifer. “Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis.” 2012. Web. 07 Dec 2019.

Vancouver:

Mindock J. Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis. [Internet] [Doctoral dissertation]. University of Colorado; 2012. [cited 2019 Dec 07]. Available from: http://scholar.colorado.edu/asen_gradetds/47.

Council of Science Editors:

Mindock J. Development and Application of Spaceflight Performance Shaping Factors for Human Reliability Analysis. [Doctoral Dissertation]. University of Colorado; 2012. Available from: http://scholar.colorado.edu/asen_gradetds/47


University of Colorado

2. Zea, Luis. Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight.

Degree: PhD, Aerospace Engineering Sciences, 2015, University of Colorado

spaceflight; however, the underlying mechanisms responsible for this outcome are not fully understood. In particular, it is not yet clear whether this observed response is due to increased drug resistance (a microbial defense response) or decreased drug efficacy (a microgravity biophysical mass transport effect). To gain insight into the differentiation between these two potential causes, an investigation was undertaken onboard the International Space Station (ISS) in 2014 termed Antibiotic Effectiveness in Space-1 (AES- 1). For this purpose, E. coli was challenged with two antibiotics, Gentamicin Sulfate and Colistin Sulfate, at concentrations higher than those needed to inhibit growth on Earth. Phenotypic parameters (cell size, cell envelope thickness, population density and lag phase duration) and gene expression were compared between the spaceflight samples and ground controls cultured in varying levels of drug concentration. It was observed that flight samples proliferated in antibiotic concentrations that were inhibitory on Earth, growing on average to a 13-fold greater concentration than matched 1g controls. Furthermore, at the highest drug concentrations in space, E. coli cells were observed to aggregate into visible clusters. In spaceflight, cell size was significantly reduced, translating to a decrease in cell surface area to about one half of the ground controls. Smaller cell surface area can in turn proportionally reduce the rate of antibiotic molecules reaching the cell. Additionally, it was observed that genes –- in some cases more than 2000 –- were overexpressed in space with respect to ground controls. Up-regulated genes include poxB, which helps catabolize glucose into organic acids that alter acidity around and inside the cell, and the gadABC family genes, which confer resistance to extreme acid conditions. The next step is to characterize the mechanisms behind the observed gene expression, its implications, and most importantly, how this knowledge can help prevent the acquisition and spread of antibiotic resistance in pathogens on Earth. Advisors/Committee Members: David M. Klaus, Louis Stodieck, Macarena Parra, JoAnn Silverstein, Sedat Biringen.

Subjects/Keywords: Bacteria; Drug; Drug-resistant; Gravity; Space; Aerospace Engineering; Microbiology; Pharmacology

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

APA (6th Edition):

Zea, L. (2015). Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight. (Doctoral Dissertation). University of Colorado. Retrieved from http://scholar.colorado.edu/asen_gradetds/96

Chicago Manual of Style (16th Edition):

Zea, Luis. “Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight.” 2015. Doctoral Dissertation, University of Colorado. Accessed December 07, 2019. http://scholar.colorado.edu/asen_gradetds/96.

MLA Handbook (7th Edition):

Zea, Luis. “Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight.” 2015. Web. 07 Dec 2019.

Vancouver:

Zea L. Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight. [Internet] [Doctoral dissertation]. University of Colorado; 2015. [cited 2019 Dec 07]. Available from: http://scholar.colorado.edu/asen_gradetds/96.

Council of Science Editors:

Zea L. Phenotypic and Gene Expression Responses of E. coli to Antibiotics during Spaceflight. [Doctoral Dissertation]. University of Colorado; 2015. Available from: http://scholar.colorado.edu/asen_gradetds/96


University of Colorado

3. Niederwieser, Tobias. Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System.

Degree: PhD, 2018, University of Colorado

Algal-based life support systems offer a promising bioregenerative technology for future human space missions by performing the functions of air revitalization, water recycling, and food production. However, despite six decades of active research, no algal-based life support systems have yet been used in a spacecraft. This dissertation analyzes key factors affecting the implementation of an algal photobioreactor into a spacecraft life support system. A comprehensive set of optimum parameters for growing <i>Chlorella vulgaris</i> in a spacecraft was defined to identify research gaps regarding the influence of atmospheric pressure, gravity, contaminants, and radiation as unique cabin environmental factors. From this starting point, the first known comprehensive publication featuring an international and fully historical review of algal spaceflight experiments was completed. Then, using a newly developed and validated flow-through test stand to measure algal metabolism and growth under altered gas compositions and pressures, it was demonstrated that altered total cabin pressure within spacecraft relevant ranges (8.2-14.7 psia) while maintaining normoxic conditions did not affect algal growth or metabolism for the conditions evaluated. Additionally, this dissertation features the first known combination of metabolic measurements with metagenomic analysis of non-axenic cultures representative of spacecraft operational environments. Promoting bacterial contamination, together with a variety of green algal taxa, provides novel insight for interpreting results across different algal metabolism studies. The effect of select typical spacecraft chemical contaminants was also assessed. Finally, a first-order feasibility analysis was conducted that established a minimum algal culture volume of 15 liters as being sufficient to support one human in terms of air and water regeneration under ideal performance conditions. This finding was then used to derive the accompanying infrastructure and support requirements that were incorporated into a conceptual design of the system. The data obtained from this work can be used to support an Equivalent System Mass (ESM) analysis or trade study for spacecraft implementation. Additionally, this thesis serves as a basis for future modelling and experimental verification work needed to increase the Technology Readiness Level (TRL) of algal life support systems that can ultimately help enable sustainable, long-duration human exploration of space. Advisors/Committee Members: David Klaus, James Nabity, Louis Stodieck, Patrick Kociolek, Alexander Hoehn.

Subjects/Keywords: bioastronautics; bioregenerative life support system; environmental control and life support system; human exploration; human spaceflight; photosynthesis; Aerospace Engineering; Biology

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

APA (6th Edition):

Niederwieser, T. (2018). Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/asen_gradetds/241

Chicago Manual of Style (16th Edition):

Niederwieser, Tobias. “Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System.” 2018. Doctoral Dissertation, University of Colorado. Accessed December 07, 2019. https://scholar.colorado.edu/asen_gradetds/241.

MLA Handbook (7th Edition):

Niederwieser, Tobias. “Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System.” 2018. Web. 07 Dec 2019.

Vancouver:

Niederwieser T. Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System. [Internet] [Doctoral dissertation]. University of Colorado; 2018. [cited 2019 Dec 07]. Available from: https://scholar.colorado.edu/asen_gradetds/241.

Council of Science Editors:

Niederwieser T. Analysis of Factors Affecting the Implementation of an Algal Photobioreactor into a Spacecraft Life Support System. [Doctoral Dissertation]. University of Colorado; 2018. Available from: https://scholar.colorado.edu/asen_gradetds/241

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