1,382 research outputs found
Study of Multimission Modular Spacecraft (MMS) propulsion requirements
The cost effectiveness of various propulsion technologies for shuttle-launched multimission modular spacecraft (MMS) missions was determined with special attention to the potential role of ion propulsion. The primary criterion chosen for comparison for the different types of propulsion technologies was the total propulsion related cost, including the Shuttle charges, propulsion module costs, upper stage costs, and propulsion module development. In addition to the cost comparison, other criteria such as reliability, risk, and STS compatibility are examined. Topics covered include MMS mission models, propulsion technology definition, trajectory/performance analysis, cost assessment, program evaluation, sensitivity analysis, and conclusions and recommendations
Bibliography on Optical Information and Data Processing
Bibliography on optical information and data processin
Safety and Efficacy of Biologic Agents for the Management of Inflammatory Bowel Disease After Liver Transplantation
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141779/1/phar2036.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141779/2/phar2036_am.pd
Testing the malicious USB anecdote
In today’s computer security climate, attacks against computers are becoming increasingly sophisticated and cheaper to execute. In this thesis, we present the results of a study conducted on the University of Illinois campus to determine the effectiveness of dropping 297 “infected” USB flash drives in a public place as an attack vector. A self-report survey given to 71 individuals highlights some of the psychological processes that motivate people to plug in the flash drives. We find that this type of attack is generally effective and relatively insensitive to its precise environmental configuration. Generally, participants expressed desire to return the flash drives to their owners, although our data shows that they also explored the contents of the flash drives on occasion
Studies and analyses of the space shuttle main engine: High-pressure oxidizer turbopump failure information propagation model
The high-pressure oxidizer turbopump (HPOTP) failure information propagation model (FIPM) is presented. The text includes a brief discussion of the FIPM methodology and the various elements which comprise a model. Specific details of the HPOTP FIPM are described. Listings of all the HPOTP data records are included as appendices
Grasshopper herbivory immediately affects element cycling but not export rates in an N-limited grassland system
Iron as recyclable energy carrier: Feasibility study and kinetic analysis of iron oxide reduction
Carbon-free and sustainable energy storage solutions are required to mitigate climate change. One possible solution, especially for stationary applications, could be the storage of energy in metal fuels. Energy can be stored through reduction of the oxide with green hydrogen and be released by combustion. In this work a feasibility study for iron as possible metal fuel considering the complete energy cycle is conducted. On the basis of equilibrium calculations it could be shown that the power-to-power efficiency of the iron/iron oxide cycle is 27 %. As technology development requires a more detailed description of both the reduction and the oxidation, a first outlook is given on the kinetic analysis of the reduction of iron oxides with hydrogen. Thermogravimetric experiments using FeO, FeO and FeO indicate a three-step process for the reduction. The maximum reduction rate can be achieved with a hydrogen content of 25 %. Based on the experimental results a reaction mechanism and accompanied kinetic data were developed for description of FeO reduction with H under varying experimental conditions
Influencia de la localización del almidón nativo de yuca en el canal de sedimentación sobre la calidad del almidón agrio.
El proceso productivo del almidón de yuca
realizado artesanalmente en el Norte del
Departamento del Cauca, incluye una etapa de
sedimentación que actualmente se lleva a cabo
en canales. Entre los procesadores de yuca de la
región existe la opinión, que del inicio del canal se obtiene almidón agrio con un poder de expansiónmás alto, y por lo tanto se podría vender a un mejor precio. En la presente investigación se analiza si existe una estratificación de calidades de acuerdo a la
posición del almidón en el canal. Se evaluaron dos
estrategias de recoger el almidón de los canales, a lo largo o perpendicular al canal. Los resultados obtenidos son negativos. Ninguna de las
estrategias permite una estratificación de
calidades tan significante para que se logre
obtener almidones que respondan a las
exigencias de los diferentes mercados. Si se
busca una calidad homogénea, se recomienda
recoger el almidón perpendicular al canal
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Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology. Quarterly Report, January 1--March 31, 1996
The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity; (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions; and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors. The main part of this report describes tracer studies of slurry bubble column hydrodynamics during methanol synthesis
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