Selecting Projects for a Capstone Spacecraft Design Course from Real World Solicitations

The first decision that goes into setting the tone for a senior capstone spacecraft design course is the choice of the projects. There are several sources of ideas for design projects, including design competitions and topics set by various technical committees. A new source of design ideas comes from real world design projects. The National Aeronautics and Space Administration\u27s Office of Space Science originally released an Announcement of Opportunity in spring 2002 to solicit designs for a complete Mars mission. The Senior Capstone Spacecraft Design course in the Department of Aerospace Engineering at The Pennsylvania State University paralleled this proposal process for the spacecraft design projects for the 2002-2003 academic year. While the original announcement called for proposers to determine what kind of a flight mission they would conduct, eight specific, realistic flight missions were chosen and assigned to the eight teams in the class. Many of the important aspects of the original project were duplicated; however, a significant amount of material was deleted. This paper discusses the outcome of the year-long course, compares some of the designs developed by the students to the designs chosen in the actual NASA mission design, and draws conclusions about the advantages and disadvantages of selecting a project based from a real solicitation

Biogenesis of the mitochondrial phosphate carrier

The mitochondrial phosphate carrier (PiC) is a member of the family of inner-membrane carrier proteins which are generally synthesized without a cleavable presequence. Surprisingly, the cDNA sequences of bovine and rat PiC suggested the existence of an amino-terminal extension sequence in the precursor of PiC. By expressing PiC in vitro, we found that PiC is indeed synthesized as a larger precursor. This precursor was imported and proteolytically processed by mitochondria, whereby the correct amino-terminus of the mature protein was generated. Import of PiC showed the characteristics of mitochondrial protein uptake, such as dependence on ATP and a membrane potential and involvement of contact sites between mitochondrial outer and inner membranes. The precursor imported in vitro was correctly assembled into the functional form, demonstrating that the authentic import and assembly pathway of PiC was reconstituted when starting with the presequence-carrying precursor. These results are discussed in connection with the recently postulated role of PiC as an import receptor located in the outer membrane

Effects of Expert Testimony and Interrogation Tactics on Perceptions of Confessions

Evidence obtained through the process of interrogation is frequently undermined by what can be perceived as overzealous interrogation tactics. Although the majority of psychologically oriented tactics are legally permissible, they nonetheless contribute to innocent suspects confessing to crimes they did not commit. The present study examined the effect of expert testimony and interrogation tactics on perceptions of a confession. 182 undergraduates read a transcript of a homicide trial that varied based on interrogation tactic: implicit threat of punishment (maximization) or leniency (minimization) and expert witness testimony (presence or absence of expert testimony). Analysis indicated that the type of interrogation tactic used in obtaining the confession affected participants\u27 perceptions of the coerciveness of the interrogation process

Development of the Circulation Control Flow Scheme Used in the NTF Semi-Span FAST-MAC Model

The application of a circulation control system for high Reynolds numbers was experimentally validated with the Fundamental Aerodynamic Subsonic Transonic Modular Active Control semi-span model in the NASA Langley National Transonic Facility. This model utilized four independent flow paths to modify the lift and thrust performance of a representative advanced transport type of wing. The design of the internal flow paths highlights the challenges associated with high Reynolds number testing in a cryogenic pressurized wind tunnel. Weight flow boundaries for the air delivery system were identified at mildly cryogenic conditions ranging from 0.1 to 10 lbm/sec. Results from the test verified system performance and identified solutions associated with the weight-flow metering system that are linked to internal perforated plates used to achieve flow uniformity at the jet exit

Quantification of crypt and stem cell evolution in the normal and neoplastic human colon.

Human intestinal stem cell and crypt dynamics remain poorly characterized because transgenic lineage-tracing methods are impractical in humans. Here, we have circumvented this problem by quantitatively using somatic mtDNA mutations to trace clonal lineages. By analyzing clonal imprints on the walls of colonic crypts, we show that human intestinal stem cells conform to one-dimensional neutral drift dynamics with a "functional" stem cell number of five to six in both normal patients and individuals with familial adenomatous polyposis (germline APC(-/+)). Furthermore, we show that, in adenomatous crypts (APC(-/-)), there is a proportionate increase in both functional stem cell number and the loss/replacement rate. Finally, by analyzing fields of mtDNA mutant crypts, we show that a normal colon crypt divides around once every 30-40 years, and the division rate is increased in adenomas by at least an order of magnitude. These data provide in vivo quantification of human intestinal stem cell and crypt dynamics.This study was supported by Cancer Research UK (to A.-M.B. and N.A.W.), the Medical Research Council (to B.C. and S.A.C.M.), the Engineering and Physical Sciences Research Council (to A.G.F.), Microsoft Research (to A.G.F.), the National Institute for Health Research University College London Hospitals Biomedical Research Centre (to M.R.J.), the Dutch Cancer Research Foundation (to M.J.), the Wellcome Trust (to B.D.S.), and Higher Education Funding Council for England (to T.A.G.)

Language and cultural capital in school experience of Polish children in Scotland

This article addresses the complex relationship between migration and education in the context of recent intra-European labour mobility. It considers how this mobility impacts the education and life chances of migrant students attending schools in Scotland, UK. By examining the experiences of Polish migrant children and youth at schools in Scotland, the article engages with the issues of language, cultural capital transferability and social positioning. Drawing on qualitative data from 65 in-depth interviews with school children aged 5–17 years, their parents and teachers, as well as observations in the contexts of school and home, the article points to a range of factors affecting the transition of migrant pupils to new schools and social environments

Unified View of Scaling Laws for River Networks

Scaling laws that describe the structure of river networks are shown to follow from three simple assumptions. These assumptions are: (1) river networks are structurally self-similar, (2) single channels are self-affine, and (3) overland flow into channels occurs over a characteristic distance (drainage density is uniform). We obtain a complete set of scaling relations connecting the exponents of these scaling laws and find that only two of these exponents are independent. We further demonstrate that the two predominant descriptions of network structure (Tokunaga's law and Horton's laws) are equivalent in the case of landscapes with uniform drainage density. The results are tested with data from both real landscapes and a special class of random networks.Comment: 14 pages, 9 figures, 4 tables (converted to Revtex4, PRE ref added