The design of a long range megatransport aircraft

During the period from August 1991 - June 1992 two design classes at Purdue University participated in the design of a long range, high capacity transport aircraft, dubbed the megatransport. Thirteen Purdue design teams generated RFP's that defined passenger capability and range, based upon team perception of market needs and infrastructure constraints. Turbofan engines were designed by each group to power these aircraft. The design problem and the variety of solutions developed are described in an attached paper

Proxy records of paleohurricanes for the western and southern caribbean

This dissertation evaluates the hypothesis that hurricane activity levels in the North Atlantic during the late Holocene have been driven by latitudinal movements of the North Atlantic circulation system. Multi-millennial sedimentary proxy records, based on the occurrence of overwash clastic layers, provide clear evidence of abruptly alternating periods of hurricane landfall frequency for Nicaragua and Belize. Three Belizean transects exhibit an Active period (hyperactivity) occurring from ~2000-6000 cal yr BP, although dating is inconsistent across the transects. An Active period covering the last 500 years is found at one location. The Nicaraguan record, derived from three transects covering \u3e90 km of coastline, consistently displays an Active period covering the last 800 years, preceded by a Quiet period that lasts until at least ~2800 years BP, before which time environmental factors render the sites insensitive. For both coastlines the calculated strike frequency increased by a factor of 3-12 during Active periods. The Barbados depositional record is characterized by sudden shifts from organic to clay, attributed to increased aridity, with the arid periods being roughly contemporaneous with the Active periods occurring in Belize and Nicaragua, as well as periods of southern residency of the Intertropical Convergence Zone. Latitudinal movements of a unified North Atlantic circulation system were probably the driver of these changes, with southern migration increasing both landfall frequency and aridity regionally. When correlated with published records, the timing of activity regime changes identified from our sites indicates that periods of increased hurricane activity proceed across the North Atlantic in a time-transgressive manner, with the Caribbean hyperactive period preceding that of the Gulf of Mexico. The Active period for Nicaragua beginning ~850 years BP is anti-phase with a recently published model, predicated upon basin-wide synchroneity in activity patterns. This discrepancy possibly results from differences in spatial coverage, as correlations between hurricane landfall and track patterns indicate three distinct groupings resulting from atmospheric conditions. The basin-wide pattern is derived from locations contained within a single (Atlantic coast) track set, while our time-transgressive model is derived from sites within both the Caribbean and Gulf of Mexico track sets

Taking a Juvenile into Custody: Situational Factors that Influence Police Officers\u27 Decisions

Situational factors that influence police officers decisions to take juveniles into custody were investigated. A cross-sectional self administered survey was conducted. Four-hundred and twenty-eight male and female police officers from six police districts in Cleveland Ohio completed and submitted a twenty-five item questionnaire. Using a logistic regression model the study identified: adolescents who disrespect police officers; adolescents who are out late at night; adolescent males; anyone looking suspicious; and the age of the police officer as the most significant predictors. This was an exploratory study that sought to investigate police/juvenile encounters from a street level situational perspective. The results provided a basis for continued research in this area of inquiry

Comparison of risk factors and criminogenic need among incarcerated young offender, probationary young offender and non offender samples

This research examined some of the risk/need factors that discriminate offending from non-offending youth employing three groups of adolescents at different points on the crime continuum. Non-offenders (n=30), probationary young offenders (n=28) and incarcerated young offenders (n=28), aged 16 to 18 years were subjects for whom a number of psychometric measures and other data were collected. A self-report measure of delinquent and criminal activity (SRP) was developed and used to validate group assignment along the crime continuum. Risk/need measures were predominantly psychometric and included measures of personality, drug abuse, alcohol abuse, family dysfunction, intelligence, academic achievement and the SRP. Drug abuse, family dysfunction and last complete grade were the measures which discriminated among all three groups. Increased criminality was associated with increased drug abuse problems, increased family dysfunction and a lower self-reported grade achievement level. Of lesser relevance in identifying group experiences were alcohol abuse, IQ, depression and psychiatric symptomology. The results and limitations of the study are discussed

Nuclear membrane disassembly and rupture

The nuclear envelope consists of two membranes traversed by nuclear pore complexes. The outer membrane is continuous with the endoplasmic reticulum. At mitosis nuclear pore complexes are dismantled and membranes disperse. The mechanism of dispersal is controversial: one view is that membranes feed into the endoplasmic reticulum, another is that they vesiculate. Using Xenopus egg extracts, nuclei have been assembled and then induced to breakdown by addition of metaphase extract. Field emission scanning electron microscopy was used to study disassembly. Strikingly, endoplasmic reticulum-like membrane tubules form from the nuclear surface after the addition of metaphase extracts, but vesicles were also observed. Microtubule inhibitors slowed but did not prevent membrane removal, whereas Brefeldin A, which inhibits vesicle formation, stops membrane disassembly, suggesting that vesiculation is necessary. Structures that looked like coated buds were observed and buds were labelled for β-COP. We show that nuclear pore complexes are dismantled and the pore closed prior to membrane rupturing, suggesting that rupturing is an active process rather than a result of enlargement of nuclear pores

COMPTEL neutron response at 17 MeV

The Compton imaging telescope (COMPTEL) instrument of the Gamma Ray Observatory was exposed to 17 MeV d,t neutrons prior to launch. These data were analyzed and compared with Monte Carlo calculations using the MCNP(LANL) code. Energy and angular resolutions are compared and absolute efficiencies are calculated at 0 and 30 degrees incident angle. The COMPTEL neutron responses at 17 MeV and higher energies are needed to understand solar flare neutron data

College Social Experiences Between First-Generation Students and Other Students Enrolled in a STEM Discipline at an HBCU

The primary purpose of this study was to determine the differences in the levels of social engagement between first-generation and other college students enrolled in a STEM discipline at a Historically Black College and University. A two-group ex post facto research design using a single questionnaire was used for the study. A stratified sample of 90 college students participated in the study. The data for the research questions were analyzed using descriptive and inferential statistics based upon the subscales of the College Student Experiences Questionnaire. These findings indicated that there were significant differences among first-generation and other college students who were enrolled in a STEM discipline at an HBCU. Statistically significant differences between first-generation and other college students were found for three items in the social integration category: “met other students,” (p = .017, η2 = .063); “used campus recreational facilities,” (p = .050, η2 = .043); and “became acquainted with students,” (p = .035, η2 = .050). Both groups felt that meeting others would happen “often.” Both groups differ for using campus recreational facilities and becoming acquainted with students whose family backgrounds were different. Firstgeneration students reported that “occasionally” and “often”; and the other college students felt “often” and “very often” that using campus recreational facilities and becoming acquainted with students whose family background was different would happen. The study documented the impact of the nurturing environment that exists at an HBCU and focused on the social engagement aspects of attending college. The study findings provide clues to ways that college administrators and researchers can assist first-generation college students enrolled in a STEM discipline at an HBCU. Implications for future research and policymakers are discussed

Evaluating Student Volunteer and Service-Learning Programs: A Casebook for Practitioners

Today, evaluation concepts and methods are widely available to those who plan and administer student volunteer programs. Unfortunately, however, evaluation has all too often been carried out-and written about-in ways that have robbed it of its usefulness to people dealing with the realities of day-to-day program operation. Evaluation has thus acquired the reputation among practitioners of being too complex, too costly, too time-consuming, even too threatening to be of much practical value