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Klaus, David M.

Works: 7 works in 7 publications in 1 language and 383 library holdings
Publication Timeline
Publications about David M Klaus
Publications by David M Klaus
Most widely held works by David M Klaus
Assessing feasibility of electrochromic space suit radiators for reducing extravehicular activity water consumption by Jonathan Glen Metts( file )
1 edition published in 2010 in English and held by 2 libraries worldwide
Water consumption for space suit thermal control is a limiting factor on long-term space exploration missions. A concept is proposed for an integrated, flexible suit radiator using infrared electrochromic materials for modulated heat rejection from the suit. Properties of electrochromic materials, the structure of electrochromic devices, and relevant heat transfer processes are presented as background information. Analytical methods are employed to bound theoretical performance and determine required emissivity ranges for lunar surface operations. Case studies are presented incorporating Apollo program and Advanced Walkback Test metabolic and environmental data to estimate sublimator water consumption and hypothetical water savings with the electrochromic radiator. Concepts are presented and analyzed for integrating an electrochromic radiator with existing and future space suit designs. A preliminary systems-level trade analysis is performed with the Equivalent System Mass metric used to compare this technology with the legacy sublimator and other extravehicular activity cooling technologies in development. Experimental objectives, procedures, and results are presented for both bench-top and thermal vacuum testing of electrochromic radiator materials
Characterization and measurement standardization of lunar dust abrasion for spacecraft design and operations by Ryan Lauren Kobrick( file )
1 edition published in 2010 in English and held by 2 libraries worldwide
Three-body abrasion tests, designed to be more representative of actual lunar system operational interactions, were conducted using a new tribotester with lunar simulants and industrial abrasives. Due to the ease and flexibility of changing abrasive variables and other test parameters, this device provided a versatile means of conducting abrasion testing to evaluate candidate materials for use in planetary exploration systems
A systematic process for assessing human spacecraft conceptual designs in terms of relative safety and operational characteristics by Kevin Paul Higdon( file )
1 edition published in 2012 in English and held by 1 library worldwide
The research efforts in this dissertation are focused on reducing uncertainty in the conceptual design phase through a process of establishing a minimum functionality baseline before trading Safety and Operability in proposed spacecraft configurations. The challenge in human spacecraft development is how to combine the parts into a working design that complies with many requirements for top level mission objectives, safety, and mission success. The design methodologies presented here provides designers and decision makers with additional methods that provide an overall view of candidate design concepts
Development and application of spaceflight performance shaping factors for human reliability analysis by Jennifer Mindock( file )
1 edition published in 2012 in English and held by 1 library worldwide
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
Buoyancy-Driven Fluid Flow Generated by Bacterial Metabolism and its Proposed Relationship to Increased Bacterial Growth in Space ( file )
1 edition published in 2005 in English and held by 0 libraries worldwide
Previous investigations have reported that bacterial growth increases in space flight; however, the underlying physical mechanisms responsible for these changes have not been fully determined. As bacteria consume nutrients, they excrete by-products whose presence can influence the onset of exponential growth and affect final cell population density. It is assumed that these metabolic processes create a reduced-density fluid zone and/or a solute gradient around each cell. On Earth, this density difference may result in local buoyancy-driven convection of the excreted by-products. The absence of convection and sedimentation in the low-gravity space flight environment, however, can be expected to alter the fluid dynamics surrounding the cells by limiting transport to diffusion only. Based on this biophysical model, it was hypothesized that acceleration affects the lag phase duration and final cell concentration of suspended bacterial cultures in a predictable, non-linear manner, due to the resultant changes incurred in the extracellular fluid composition. Eight experiments at various levels of acceleration consistently supported this hypothesis, resulting in predictable growth kinetics. In additional experiments, macroscopic plumes of fluid were observed and analyzed rising from metabolizing bacterial cultures. If similar fluid dynamics were found to occur on a microscopic level, it would help explain how acceleration affects bacterial growth kinetics
Defining an abrasion index for lunar surface systems as a function of dust interaction modes and variable concentration zones by Ryan L Kobrick( file )
1 edition published in 2010 in English and held by 0 libraries worldwide
Validation of proposed metrics for two-body abrasion scratch test analysis standards by Ryan L Kobrick( file )
1 edition published in 2011 in English and held by 0 libraries worldwide
English (7)
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