Controlled Ecological Life Support Systems (CELSS) physiochemical waste management systems evaluation

Parametric data for six waste management subsystems considered for use on the Space Station are compared, i.e.: (1) dry incineration; (2) wet oxidation; (3) supercritical water oxidation; (4) vapor compression distillation; (5) thermoelectric integrated membrane evaporation system; and (6) vapor phase catalytic ammonia removal. The parameters selected for comparison are on-orbit weight and volume, resupply and return to Earth logistics, power consumption, and heat rejection. Trades studies are performed on subsystem parameters derived from the most recent literature. The Boeing Engineering Trade Study (BETS), an environmental control and life support system (ECLSS) trade study computer program developed by Boeing Aerospace Company, is used to properly size the subsystems under study. The six waste treatment subsystems modeled in this program are sized to process the wastes for a 90-day Space Station mission with an 8-person crew, and an emergency supply period of 28 days. The resulting subsystem parameters are compared not only on an individual subsystem level but also as part of an integrated ECLSS

Efficient water management practices

Presented at Competing interests in water resources - searching for consensus: proceedings from the USCID water management conference held on December 5-7, 1996 in Las Vegas, Nevada.In September 1990, AB 3616, "The Agricultural Water Suppliers Act," became law in California. This law required the Department of Water Resources (DWR) to establish an advisory committee to review and study potential Efficient Water Management Practices (EWMPs) and to determine which were feasible for achieving water conservation. The advisory committee was comprised of representatives of the California farming community, agricultural water suppliers, the Department of Food and Agriculture, the University of California, the California State University, public interest groups, and other interested parties. During 1992, the last year of California's six year drought, Governor Wilson, in a speech discussing California's water needs, referred to the many water conservation practices developed by California's farmers and expressed his support for the development of EWMPs for agricultural water use. He further emphasized the AB 3616 Advisory Committee should develop a strategy for implementing these practices. An Urban Memorandum of Understanding (MOU) had recently been signed by urban water suppliers and public interest groups (environmentalists). The urban signatories committed to implement certain Best Management Practices during a specific time frame to help reduce future demand and conserve water supplies. The Governor was hopeful a similar MOU could be developed for agricultural water suppliers which would encourage further improvements in water management. The Governor's directive changed the purpose of the AB 3616 Advisory Committee. Not only was a list of efficient water management practices to be prepared, but a document was also needed which outlined a reasonable implementation plan acceptable to both agricultural and environmental representatives. Since 1992, the Advisory Committee members have been working to develop an acceptable MOU. There have been many meetings, disagreements, and at times uncertainty over whether a workable product could be developed. The Advisory Committee approved the Final Draft MOU on October 15, 1996. Can it work and will it be effective in further improving agricultural water management or is it just another layer of bureaucracy? This paper will discuss the process followed, areas of disagreement, and what steps were taken to reach a consensus

An interesting diagnosis for a presacral mass: case report

A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented

A Frequency-Controlled Magnetic Vortex Memory

Using the ultra low damping NiMnSb half-Heusler alloy patterned into vortex-state magnetic nano-dots, we demonstrate a new concept of non-volatile memory controlled by the frequency. A perpendicular bias magnetic field is used to split the frequency of the vortex core gyrotropic rotation into two distinct frequencies, depending on the sign of the vortex core polarity $p=\pm1$ inside the dot. A magnetic resonance force microscope and microwave pulses applied at one of these two resonant frequencies allow for local and deterministic addressing of binary information (core polarity)

Putting theory oriented evaluation into practice

Evaluations of gaming simulations and business games as teaching devices are typically end-state driven. This emphasis fails to detect how the simulation being evaluated does or does not bring about its desired consequences. This paper advances the use of a logic model approach which possesses a holistic perspective that aims at including all elements associated with the situation created by a game. The use of the logic model approach is illustrated as applied to Simgame, a board game created for secondary school level business education in six European Union countries