Heat pipes for wing leading edges of hypersonic vehicles

Wing leading edge heat pipes were conceptually designed for three types of vehicle: an entry research vehicle, aero-space plane, and advanced shuttle. A full scale, internally instrumented sodium/Hastelloy X heat pipe was successfully designed and fabricated for the advanced shuttle application. The 69.4 inch long heat pipe reduces peak leading edge temperatures from 3500 F to 1800 F. It is internally instrumented with thermocouples and pressure transducers to measure sodium vapor qualities. Large thermal gradients and consequently large thermal stresses, which have the potential of limiting heat pipe life, were predicted to occur during startup. A test stand and test plan were developed for subsequent testing of this heat pipe. Heat pipe manufacturing technology was advanced during this program, including the development of an innovative technique for wick installation

A Review of Choice and Preference Assessments to Increase Academic Attainment for Autism Spectrum Disorders

Many schools use choice and preference assessments to decrease and/or increase behaviors of students with disabilities such as Autism Spectrum Disorders or ASD. Although there exists scant evidence from the literature exploring the relationship between utilizing choice and preference assessments as a tool to increase academic achievement, the Council for Exceptional Children’s (CEC ) “ Initial Level Special Educator Preparation Standards” require beginning special education professionals to, “select, adapt, and use a repertoire of evidence-based instructional strategies to advance learning of individuals with exceptionalities,” (CEC, 2012). To contribute to the knowledge base regarding using choice and preference assessment as a tool to increase academic attainment, this article provides a brief examination of the existing literature by reviewing four studies based on the following criteria: (a) participants referred for intervention based upon poor academic performance, (b) participants ranging from primary or elementary-grade students with or without identified disabilities, (c) studies examined the use of preference assessment to increase academic achievement, and (d) studies published in a peer reviewed publication within the past fifteen years. Findings from these studies produced mixed results and left the original purpose and question of the article review unanswered. The mixed results and conclusions drawn highlight the need for future research to be conducted to evaluate the effectiveness of choice and preference assessments as a tool to increase academic achievement for students with ASD

Catastrophic Risk Evaluation

A body of empirical evidence has shown that many managers would welcome new ways of highlighting catastrophic consequences, as well as means to evaluating decision situations involving high risks. When events occur frequently and their consequences are not severe, it is relatively simple to calculate the risk exposure of an organisation, as well as a reasonable premium when an insurance transaction is made. The usual methods rely on variations of the principle of maximising the expected utility (PMEU). When, on the other hand, the frequency of damages is low, the situation is considerably more difficult, especially if catastrophic events occur. When the quality of estimates is poor, e.g., when evaluating low-probability/high-consequence risks, the customary use of quantitative rules together with overprecise data could be harmful as well as misleading. This work extends the risk evaluation process by the integration of procedures for handling vague and numerically imprecise probabilities and utilities. The shortcomings of PMEU, and of utility theory in general, can in part be compensated for by the introduction of risk constraints. We point out some problematic features of the evaluations performed using utility theory. We also criticise the demand for precise data in situations where none is available. As an alternative to traditional models, we suggest a method for the evaluation of risks when the information at hand is numerically imprecise. The method includes procedures that allow for interval statements and comparisons, and thereby it does not require the use of numerically precise statements of probability, cost, or utility in a general sense. In order to attain a reasonable level of security, and because it has been shown that managers tend to focus on large negative losses, it is argued that a risk constraint should be imposed on the analysis. The strategies are evaluated relative to a set of such constraints considering how risky the strategies are

Characterization of temporal and spatial variation in subwatersheds of the Strawberry River, AR, prior to implementation of agricultural best management practices

Benthic macroinvertebrate (BMI) assessments indicate alterations in physical and/or chemical factors making them valuable tools when attempting to assess agricultural best management practices (BMPs). The purpose of this study was to obtain pre-BMP land cover and macroinvertebrate community data in order to characterize temporal and spatial variation in three catchments: Little Strawberry (LS), Greasy Creek (GC), and Sandy Creek (SC) of the Strawberry River Watershed, located in north central Arkansas, in order to establish baseline conditions. BMIs were collected for the three subwatersheds in 1995, 1999, 2002, 2003 and 2009. Taxa richness, Hilsenhoff Biotic Index (HBI) and Ephemeroptera, Plecoptera and Trichoptera (EPT) score, % dominant taxa, and % Diptera were used as indicators of water quality and habitat changes. All subwatersheds experienced decreased forest land cover indicating land use transition. All resulting BMI measures indicate overall stable habitat and water conditions in the LS subwatershed. Results for GC subwatershed vary with taxa richness, EPT and HBI indicating a stable habitat while increasing % dominant taxa and Diptera indicate a decreasing trend in overall habitat quality. All BMI measures in the SC subwatershed indicate decreasing trend in habitat quality. The most sensitive measure to temporal changes was % Diptera. Trends were not consistent among subwatersheds indicating the importance of continued data collection to establish baseline data and truly monitor changes in aquatic systems over time

Weighted Radon transforms for which the Chang approximate inversion formula is precise

We describe all weighted Radon transforms on the plane for which the Chang approximate inversion formula is precise. Some subsequent results, including the Cormack type inversion for these transforms, are also given

An Efficient Parallel Solver for SDD Linear Systems

We present the first parallel algorithm for solving systems of linear equations in symmetric, diagonally dominant (SDD) matrices that runs in polylogarithmic time and nearly-linear work. The heart of our algorithm is a construction of a sparse approximate inverse chain for the input matrix: a sequence of sparse matrices whose product approximates its inverse. Whereas other fast algorithms for solving systems of equations in SDD matrices exploit low-stretch spanning trees, our algorithm only requires spectral graph sparsifiers

Implementation of advanced practice nursing for orthopaedic patients in the emergency care context – A study protocol for outcome studies

Aim. To evaluate the implementation of advanced practice nursing in emergency care in Norway for patients with orthopedic injuries, including hip fractures. The outcomes relate to quality of care and patient trust. Design. A non-inferiority study comparing an advanced practice nursing care model with a standard (physician-led) care model. Methods. Data will be collected from patient records and through the Patient Trust Questionnaire, completed by patients. The data will be analysed by descriptive and inferential statistics. Funding for the research was granted in 2015 and the regional ethical committee approved the current study in February 2019. Discussion. In Norway and the other Nordic countries, advanced practice nursing is still in its infancy, especially in the emergency care context. This study will evaluate advanced practice nursing in this new context. Impact. The study will add to knowledge on the quality of care provided for orthopedic patients with minor orthopedic injuries or hip fractures as delivered by advanced practice nurses and physicians, respectively. It will also evaluate how well advanced practice nursing is accepted by patients in this new context

Implementation of advanced practice nursing for minor orthopedic injuries in the emergency care context – a non-inferiority study

Aims To evaluate the implementation of advanced practice nursing for patients with minor orthopedic injuries, including comparison of outcomes in relation to advanced practice nurse versus standard (physician-led) care models. Design A non-inferiority study was performed in an emergency department in Norway, where advanced practice nursing is in an initial stage of implementation. The non-inferiority design was chosen to test whether the new advanced practice nursing model does not compromise quality of care compared to the standard care model already in use. Methods Patients with minor orthopedic injuries were assessed and treated by either advanced practice nursing or standard (physician-led) care models. Participating patients were assigned to the professional available at presentation. In the nursing model, registered nurses worked at an advanced level/applied advanced practice nursing following in-house-training. Senior orthopedic specialists evaluated the diagnostic and treatment accuracy in both models. Data were collected in a tool developed for this study, from May to October, 2019. Results In total, 335 cases were included, of which 167 (49.9 %) were assessed and treated in the nursing model. Overall, correct diagnosis was found in 97.3 % (n = 326) of the cases, and correct treatment was found in 91.3 % (n = 306) of the cases. In comparison of missed diagnosis between advanced practice nurse and the standard (physician-led) care model showed inconclusive results (risk ratio: 0.29, 95% CI: 0.06-1.36). In comparison of treatment outcomes, the results showed that the advanced practice nursing model was non-inferior (risk ratio: 0.45, 95% CI: 0.21-0.97). Conclusion Advanced practice nursing care models can be used to diagnose and treat minor orthopedic injuries without compromising quality of care. Further implementation of the advanced practice nurse care model is encouraged