Design and construction of a liquid nitrogen cryostat for use in a swimming pool type reactor

The continued expansion of the nuclear reactor facility and the nuclear engineering program dictates the need that a liquid nitrogen cooled cryostat be available at the reactor. This unit would be available for use in graduate and undergraduate laboratories and for graduate research. A liquid nitrogen cooled cryostat capable of maintaining a sample between 77°K to 80°K for an extended period of time in or adjacent to the core of the reactor was designed, constructed, and successfully operated. Recommendations were made for possible modifications to expand the versatility of the system --Abstract, page ii

An Investigation of Racial Attitudes Among White Pre-Service Teachers

The purpose of this study was to examine White American prospective teachers\u27 racial attitudes about African Americans. In the age of multiculturalism, it is important to address the issue of racism and racial attitudes among educators. Racism continues to influence many aspects of American society, particularly education. Though the face of racism has changed from its blatant forms, it is now manifested in more subtle forms, and has thus been named new racism. This study investigated the level of new racism among White American prospective teachers enrolled in a teacher education program. Jacobson\u27s New Racism Scale was used to determine the level of new racism. The results of the study suggest that there is a need to further investigate racist attitudes among prospective teachers

Being Safe on the College Campus [brochure and video]

Parents experience many emotions when sending their students away for college. Many are excited for their child, some are sad, and a majority of these parents are worried. Parents now have to worry for a child that they are no longer in the same town as, whom they can no longer set a curfew and monitor when at home. Though people would like to believe that the university their child has chosen is safe the numbers tell a different story. According to Readers Digest (2008) of this country’s 6,000 colleges and universities there are 40,000 burglaries, 3,700 forcible sex offenses, 7,000 aggravated assaults and 48 murders reported a year. In the last ten years universities are learning from past failings in safety and taking steps to be safer. Learning from these mistakes many universities have installed numerous policies and procedures to ensure safety. All students, university employees and guest deserve to feel that they live and work in a safe place. There should be no fear when leaving dorm rooms, walking to class, or studying in the library. But a university can only do so much. Students should be trained on campus safety and responsible decision making. Students only fear should be finals week, not their personal safety

Development of an innovative validation strategy of gas–surface interaction modelling for re‑entry applications

Abstract This paper summarises the final synthesis of an ESA technology research programme entitled “Development of an Innovative Validation Strategy of Gas Surface Interaction Modelling for Re-entry Applications”. The focus of the project was to demonstrate the correct pressure dependency of catalytic surface recombination, with an emphasis on Low Earth Orbit (LEO) re-entry conditions and thermal protection system materials. A physics-based model describing the prevalent recombination mechanisms was proposed for implementation into two CFD codes, TINA and TAU. A dedicated experimental campaign was performed to calibrate and validate the CFD model on TPS materials pertinent to the EXPERT space vehicle at a wide range of temperatures and pressures relevant to LEO. A new set of catalytic recombination data was produced that was able to improve the chosen model calibration for CVD-SiC and provide the first model calibration for the Nickel–Chromium super-alloy PM1000. The experimentally observed pressure dependency of catalytic recombination can only be reproduced by the Langmuir–Hinshelwood recombination mechanism. Due to decreasing degrees of (enthalpy and hence) dissociation with facility stagnation pressure, it was not possible to obtain catalytic recombination coefficients from the measurements at high experimental stagnation pressures. Therefore, the CFD model calibration has been improved by this activity based on the low pressure results. The results of the model calibration were applied to the existing EXPERT mission profile to examine the impact of the experimentally calibrated model at flight relevant conditions. The heat flux overshoot at the CVDSiC/PM1000 junction on EXPERT is confirmed to produce radiative equilibrium temperatures in close proximity to the PM1000 melt temperature.This was anticipated within the margins of the vehicle design; however, due to the measurements made here for the first time at relevant temperatures for the junction, an increased confidence in this finding is placed on the computations

Global Free Tropospheric NO2 Abundances Derived Using a Cloud Slicing Technique Applied to Satellite Observations from the Aura Ozone Monitoring Instrument (OMI)

We derive free-tropospheric NO2 volume mixing ratios (VMRs) and stratospheric column amounts of NO2 by applying a cloud slicing technique to data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. In the cloud-slicing approach, the slope of the above-cloud NO2 column versus the cloud scene pressure is proportional to the NO2 VMR. In this work, we use a sample of nearby OMI pixel data from a single orbit for the linear fit. The OMI data include cloud scene pressures from the rotational-Raman algorithm and above-cloud NO2 vertical column density (VCD) (defined as the NO2 column from the cloud scene pressure to the top-of-the-atmosphere) from a differential optical absorption spectroscopy (DOAS) algorithm. Estimates of stratospheric column NO2 are obtained by extrapolating the linear fits to the tropopause. We compare OMI-derived NO2 VMRs with in situ aircraft profiles measured during the NASA Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in 2006. The agreement is generally within the estimated uncertainties when appropriate data screening is applied. We then derive a global seasonal climatology of free-tropospheric NO2 VMR in cloudy conditions. Enhanced NO2 in the free troposphere commonly appears near polluted urban locations where NO2 produced in the boundary layer may be transported vertically out of the boundary layer and then horizontally away from the source. Signatures of lightning NO2 are also shown throughout low and middle latitude regions in summer months. A profile analysis of our cloud slicing data indicates signatures of uplifted and transported anthropogenic NO2 in the middle troposphere as well as lightning-generated NO2 in the upper troposphere. Comparison of the climatology with simulations from the Global Modeling Initiative (GMI) for cloudy conditions (cloud optical thicknesses > 10) shows similarities in the spatial patterns of continental pollution outflow. However, there are also some differences in the seasonal variation of free-tropospheric NO2 VMRs near highly populated regions and in areas affected by lightning-generated NOx. Stratospheric column NO2 obtained from cloud slicing agrees well with other independently-generated estimates, providing further confidence in the free-tropospheric results

Genetic and anatomical basis of the barrier separating wakefulness and anesthetic-induced unresponsiveness.

A robust, bistable switch regulates the fluctuations between wakefulness and natural sleep as well as those between wakefulness and anesthetic-induced unresponsiveness. We previously provided experimental evidence for the existence of a behavioral barrier to transitions between these states of arousal, which we call neural inertia. Here we show that neural inertia is controlled by processes that contribute to sleep homeostasis and requires four genes involved in electrical excitability: Sh, sss, na and unc79. Although loss of function mutations in these genes can increase or decrease sensitivity to anesthesia induction, surprisingly, they all collapse neural inertia. These effects are genetically selective: neural inertia is not perturbed by loss-of-function mutations in all genes required for the sleep/wake cycle. These effects are also anatomically selective: sss acts in different neurons to influence arousal-promoting and arousal-suppressing processes underlying neural inertia. Supporting the idea that anesthesia and sleep share some, but not all, genetic and anatomical arousal-regulating pathways, we demonstrate that increasing homeostatic sleep drive widens the neural inertial barrier. We propose that processes selectively contributing to sleep homeostasis and neural inertia may be impaired in pathophysiological conditions such as coma and persistent vegetative states