Electron beam X-Y deflection system Final report

Design and fabrication of electron beam X-Y deflection system for retrofit on welding gun

Mechanics of liquid helium in a partially filled rotating dewar in low gravity with application to Gravity Probe-B

The Gravity Probe-B spacecraft is composed largely of a liquid helium dewar containing an experiment package. It is shown that an unsymmetric liquid helium distribution in the dewar can cause unacceptably high forces, gravitational and gravity gradient forces, at the experiment location. It is further shown that for the planned spacecraft configuration and operational parameters, it is very likely that the liquid helium distribution in the dewar will be unsymmetric. The required symmetry can be attained by using higher operational spacecraft rotation rates

Jet aircraft configuration Patent

Upper surface, external flow, jet-augmented flap configuration for high wing jet aircraft for noise reductio

Lubricant Selection Manual, Phase 3

Future spacecraft must be designated to operate for very long time periods in space. For example, a target goal for the Space Station is 30 years of operation. Although the actual life may be significantly less than this optimistic goal, the life will certainly be a critical issue in design. The bearings on primary components such as the alpha and beta joints must obviously be designed and lubricated with the objective of optimum performance life. In addition to these joints, there will be numerous other tribological (rubbing or rolling) interfaced that will be required to function for the life of the spacecraft. A major key to adequate performance of tribological interface is proper lubrication. Lubricants can be divided into two basic classes: solid films and liquids. Both types have been used extensively in space applications. Both have advantages and disadvantages that must be carefully considered in their selection. The purpose here is to summarize selection criteria for liquid and solid lubricants applied to long-life spacecraft

A Step Forward: A Study of the Practical Application of the No Child Left Behind Act

This thesis analyzes teachers’ perceptions of the impact NCLB has on classrooms every day. It begins with a brief literature review analyzing and synthesizing editorial articles that discuss perceptions of the successes and shortcomings of NCLB. It then describes and discusses a survey study conducted amongst teachers in Southern Virginia. Thirty teachers from three counties were surveyed, and, as expected, when given space to respond freely, they responded with negative comments toward NCLB. However, when asked to rank the impact of the No Child Left Behind Act on student success and teacher effectiveness the surveyed teachers expressed a neutral impact. These mixed results indicate a need for further studies

A Comparison of Elementary Student Curriculum Satisfaction to Performance

Elementary students need to learn keyboarding skills in order to keep up with expectations of teachers. The purposes of this study include: to explore if there is any relationship between student satisfaction with the curriculum and improvement in average words per minute (WPM), and between student improvement in WPM and their perception of whether they had improved or not. Two schools were used in this study: a lower elementary (K-2nd grades) and an upper elementary (3rd-5th grades). A keyboarding instruction program was used, and at the end of the school year two questions were asked: “Did you like the activities you did in computer lab?� and “Do you think you are better at keyboarding now?� Results indicate that the younger students tended to have a higher change in WPM when they reported that they did not enjoy the activities and vice versa for the older students. The results showed that in relation to the second question, the lower elementary students had no significant difference in improvement in WPM whether they reported “yes� or “no�. The upper elementary school showed more improvement if they answered that they thought they had improved. The results give evidence that older elementary students are able to comprehend their improvement more than the others. This may influence their view of how much they like the curriculum; or it could be because they achieve greater improvement when they enjoy the curriculum. More research needs to be done to fully understand the relationship

Fcgamma receptor-mediated phagocytosis in macrophages lacking the Src family tyrosine kinases Hck, Fgr, and Lyn.

Macrophage Fcgamma receptors (FcgammaRs) mediate the uptake and destruction of antibody-coated viruses, bacteria, and parasites. We examined FcgammaR signaling and phagocytic function in bone marrow-derived macrophages from mutant mice lacking the major Src family kinases expressed in these cells, Hck, Fgr, and Lyn. Many FcgammaR-induced functional responses and signaling events were diminished or delayed in these macrophages, including immunoglobulin (Ig)G-coated erythrocyte phagocytosis, respiratory burst, actin cup formation, and activation of Syk, phosphatidylinositol 3-kinase, and extracellular signal-regulated kinases 1 and 2. Significant reduction of IgG-dependent phagocytosis was not seen in hck(-)(/)-fgr(-)(/)- or lyn(-)(/)- cells, although the single mutant lyn(-)(/)- macrophages did manifest signaling defects. Thus, Src family kinases clearly have roles in two events leading to FcgammaR-mediated phagocytosis, one involving initiation of actin polymerization and the second involving activation of Syk and subsequent internalization. Since FcgammaR-mediated phagocytosis did occur at modest levels in a delayed fashion in triple mutant macrophages, these Src family kinases are not absolutely required for uptake of IgG-opsonized particles

Space Station long term lubrication analysis. Phase 1 preliminary tribological survey

Increases in the size, complexity, and life requirements of satellites and space vehicles have put increasing demands on the lubrication requirements for trouble-free service. Since the development costs of large systems are high, long lives with minimum maintenance are dictated. The Space Station represents the latest level of size and complexity in satellite development; it will be nearly 100 meters in major dimensions and will have a life requirement of thirty years. It will have numerous mechanisms critical to its success, some of which will be exposed to the space environment. Designing long-life lubrication systems and choosing appropriate lubricants for these systems will be necessary for their meeting the requirements and for avoiding failures with associated dependent mechanisms. The purpose of this program was to identify the various critical mechanisms and review their designs during the overall design and development stage so that problem areas could be avoided or minimized prior to the fabrication of hardware. The specific objectives were fourfold: (1) to perform a tribology survey of the Space Station for the purpose of documenting each wear point as to materials involved, environmental conditions, and operating characteristics; (2) to review each wear point (point of relative motion) as to the lubrication used and substrate materials selected in the context of its operating characteristics and the environmental conditions imposed; (3) to make recommendations for improvement in areas where the lubricant chosen and/or where the substrate (materials of the wear couple) are not considered optimum for the application; and (4) to make or recommend simulated or full scale tests in tribological areas where the state-of-the-art is being advanced, in areas where new designs are obviously being employed and a critical review would indicate that problems are a strong possibility, and/or where excessive wear, a malfunction, or excessive leakage would create fluid systems problems or contamination of exposed optical equipment

Technology Evaluation and Imitation: Do They Have Differential or Dichotomous Effects on ERP Adoption and Assimilation in China?

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Benthic Prey in a Bowhead Whale from the Northern Bering Sea

Stomach contents were examined from a bowhead whale, Balaena mysticetus, killed at Gambell, Alaska, on 1 May 1982. It contained an estimated 20-40 litres of recently ingested prey, principally gammarid amphipods (91.7% of the volume of a 157-ml subsample) and cumaceans (7%). All identified prey were primarily epibenthic forms. The stomach of this whale was significant in several respects: (1) it contained the largest amount of food recorded in any whale taken and examined in spring; (2) it provided the first direct evidence of bowheads feeding in the Bering Sea; and (3) the contents indicated that benthic prey are sometimes intentionally fed upon.Key words: Balaena mysticetus, benthic prey, Bering Sea, bowhead whale, feeding, gammarid amphipodsMots clés: Balaena mysticetus, proie benthique, mer de Béring, baleine boréale, alimentation, amphipodes gammaridé