6,894 research outputs found
Preliminary results from the advanced photovoltaic experiment flight test
The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight; limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination
Propulsion Technology Lifecycle Operational Analysis
The paper presents the results of a focused effort performed by the members of the Space Propulsion Synergy Team (SPST) Functional Requirements Sub-team to develop propulsion data to support Advanced Technology Lifecycle Analysis System (ATLAS). This is a spreadsheet application to analyze the impact of technology decisions at a system-of-systems level. Results are summarized in an Excel workbook we call the Technology Tool Box (TTB). The TTB provides data for technology performance, operations, and programmatic parameters in the form of a library of technical information to support analysis tools and/or models. The lifecycle of technologies can be analyzed from this data and particularly useful for system operations involving long running missions. The propulsion technologies in this paper are listed against Chemical Rocket Engines in a Work Breakdown Structure (WBS) format. The overall effort involved establishing four elements: (1) A general purpose Functional System Breakdown Structure (FSBS). (2) Operational Requirements for Rocket Engines. (3) Technology Metric Values associated with Operating Systems (4) Work Breakdown Structure (WBS) of Chemical Rocket Engines The list of Chemical Rocket Engines identified in the WBS is by no means complete. It is planned to update the TTB with a more complete list of available Chemical Rocket Engines for United States (US) engines and add the Foreign rocket engines to the WBS which are available to NASA and the Aerospace Industry. The Operational Technology Metric Values were derived by the SPST Sub-team in the form of the TTB and establishes a database for users to help evaluate and establish the technology level of each Chemical Rocket Engine in the database. The Technology Metric Values will serve as a guide to help determine which rocket engine to invest technology money in for future development
Annual Survey of Virginia Law: Corporate and Business Law
Virginia corporate and business law changes in the last year continue to challenge the practitioner to stay abreast of such developments in order to provide accurate advice to clients. This article summarizes the developments in the law in Virginia occurring from June 1999 through May 2000, with the legislative changes described based on Virginia General Assembly action in the 2000 session. Part II examines those legislative changes in corporate and business law (excluding public service corporation/public utility law issues). While many of the legislative changes are not significant, three new uniform laws (revised Article 9 of the Uniform Commercial Code ( UCC ), dealing with secured transactions, the Uniform Electronic Transactions Act, and the Uniform Computer Information Transactions Act) are likely to have a major impact on significant areas of business law practice and business conduct. Part III reviews judicial decisions on commercial law and business entity issues during the year, including a controversial decision on the duty of directors
CONSUMER HOME-USE EVALUATION OF A DEVELOPED LEAN GROUND BEEF PRODUCT
This study reports findings on the acceptance of a new lean ground beef product. Tested products involved 1) a Developed Lean product (less than 10% fat plus quality enhancers), 2) a Lean product (less than 10% fat without quality enhancers), and 3) a Market product (slightly more than 20% fat). These products were home delivered on a rotating basis to a random sample of 91 households, one product each week for three weeks. Product traits were evaluated by the household meal preparer at three stages of home use: preparing (5 traits), cooking (3 traits), and eating (4 traits), and by other household members at the final consumption stage of eating. More favorable ratings were observed for both Developed Lean and Lean products over the Market product at the preparing and cooking stages. Ratings at the eating stage were similar between the Developed Lean and the Market products indicating a favorable response to the Developed Lean product.Consumer/Household Economics,
The Waterloo Earth Sciences Museum
The University of Waterloo’s Earth Sciences Museum was started as a Canadian centennial project and has been part of the Department of Earth and Environmental Sciences outreach program for over 40 years. Museum initiatives include lectures; hands-on geological activities such as gold panning; construction of a rock garden; production of geology-themed books for children and adults; podcasts; and participation in gem shows, groundwater festivals and other public events. The museum benefits from public and private funding and the donation of specimens. Volunteers and co-op students allow it to function with a minimum of staff. It provides examples of the types of programs to increase public geological knowledge and understanding that can be offered by even a modest museum.
SOMMAIRE
Le Musée des Sciences de la Terre à l’Université de Waterloo était un porjet du centennaire duCanada, et depuis a fait parti d’un programme de communication du Département des Sciences de la Terre. Les initiatives incluent des conférences; des activitiés géologiques, comme le lavage de gravier pour séparer de l’or; le développement d’un jardin de rocaille; la production de livres à thèmes géologiques pour enfants et adultes; des programmes pour iPod; et la participation à des exhibitions de pierres précieuses, des festivals de l’eau souterraine et auters activites publiques. Le musée jouit de financement publique et privé, et de dons spécimens. Des bénévoles et des étudiants permettent le fonetionnement avec le minimum d’employés. Ceci offert des exemples de programmes pour améliorer les connaissances st la compréhension de la géologie pour le grand publique qu’un musée de taille modeste peut amener
Launch Vehicle Propulsion Life Cycle Cost Lessons Learned
This paper will review lessons learned for space transportation systems from the viewpoint of the NASA, Industry and academia Space Propulsion Synergy Team (SPST). The paper provides the basic idea and history of "lessons learned". Recommendations that are extremely relevant to NASA's future investments in research, program development and operations are"'provided. Lastly, a novel and useful approach to documenting lessons learned is recommended, so as to most effectively guide future NASA investments. Applying lessons learned can significantly improve access to space for cargo or people by focusing limited funds on the right areas and needs for improvement. Many NASA human space flight initiatives have faltered, been re-directed or been outright canceled since the birth of the Space Shuttle program. The reasons given at the time have been seemingly unique. It will be shown that there are common threads as lessons learned in many a past initiative
Experimental investigation of flutter of a propeller with Clark Y section operating at zero forward velocity at positive and negative blade- angle settings
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