A tabulation of pipe length to diameter ratios as a function of Mach number and pressure ratios for compressible flow

Computer programs and resulting tabulations are presented of pipeline length-to-diameter ratios as a function of Mach number and pressure ratios for compressible flow. The tabulations are applicable to air, nitrogen, oxygen, and hydrogen for compressible isothermal flow with friction and compressible adiabatic flow with friction. Also included are equations for the determination of weight flow. The tabulations presented cover a wider range of Mach numbers for choked, adiabatic flow than available from commonly used engineering literature. Additional information presented, but which is not available from this literature, is unchoked, adiabatic flow over a wide range of Mach numbers, and choked and unchoked, isothermal flow for a wide range of Mach numbers

Fatty Acid Blood Levels, Vitamin D Status, and Physical Performance and Its Relationship to Resiliency and Mood in Active Duty Soldiers

The mental health of soldiers is a growing concern as rates of depression and suicide have increased in soldiers with recently more deaths attributed to suicide than deaths due to combat in Afghanistan in 2012. Previous research has demonstrated the potential for eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), vitamin D, physical activity, and physical fitness to improve and arachidonic acid (AA) to threaten depression/quality of life scores. This study examined whether blood fatty acid levels, vitamin D status and/or physical activity are associated with physical fitness scores, measures of mood, and measures of resiliency in active duty soldiers. 100 active duty males at Fort Hood, TX underwent a battery of psychometric tests, anthropometric, fitness tests, and donated fasting blood samples. Pearson bivariate correlation analysis revealed significant correlations among psychometric tests, anthropometric, physical performance, reported physical inactivity (sitting time), and fatty acid and vitamin D blood levels. Categorical analysis revealed significant difference in levels of fatty acids and vitamin D, anthropometric, physical performance, and psychometric measures. Based on these findings, a regression equation was developed to predict a depressed mood status as determined by the Patient Health Questionnaire-9. The equation accurately predicted 80% of our participants with a sensitivity of 76.9% and a specificity of 80.5%. Results indicate that lack of physical activity and fitness, high levels of AA and low levels of EPA, DHA, and vitamin D could increase the risk of depressed mood and that use of a regression equation may be helpful in identifying soldiers at higher risk for possible intervention. Future studies should evaluate the impact of exercise and diet interventions as a means of improving resiliency and reducing depressed mood in soldiers

Attitudes of Secondary Teachers toward Mainstreaming Mildly Educationally Handicapped Students

With the enactment of Public Law 94-142, the Education For All Handicapped Children Act of 1975, while most educators have been influenced by the requirement to meet the needs of youngsters in the least restrictive environment, onus of responsibility generally filters down to the classroom teachers. It was the purpose of this study to determine just what are the attitudes of secondary teachers toward integrating the mildly educationally handicapped student into the regular class. The primary question was whether exposure to the concept of mainstreaming positively influences attitudes. The investigation involved 501 secondary teachers selected by a stratified random sampling from across the state of Iowa. They were classified into three teaching groups: regular class, special class and special education. From each category, 167 were then randomly selected in order to equally represent each teaching category. Instrumentation was accomplished through a questionnaire which solicited educator response to 20 items relating to the integration of mildly educationally handicapped students into the secondary classroom. Analysis of variance results were obtained. Conclusions of the study, as taken from the selected population, indicated that attitudes were significantly associated positively with teacher assignment (special education), prior contact (yes), perceived adequacy of training (adequate) and gender of the teacher (female). Degree held, years of teaching experience and community service(d) affected attitudes only insofar as they were mediated by the four more dominant factors. When all independent variables were paired with each other in 21 conditions, no instance of significant interaction effects were discovered. All independent variables were found to be operating independently of each other in their relationship to receptivity scores

Runtime Verification of Temporal Properties over Out-of-order Data Streams

We present a monitoring approach for verifying systems at runtime. Our approach targets systems whose components communicate with the monitors over unreliable channels, where messages can be delayed or lost. In contrast to prior works, whose property specification languages are limited to propositional temporal logics, our approach handles an extension of the real-time logic MTL with freeze quantifiers for reasoning about data values. We present its underlying theory based on a new three-valued semantics that is well suited to soundly and completely reason online about event streams in the presence of message delay or loss. We also evaluate our approach experimentally. Our prototype implementation processes hundreds of events per second in settings where messages are received out of order.Comment: long version of the CAV 2017 pape

Runtime verification of parametric properties using SMEDL

Parametric properties are typical properties to be checked in runtime verification (RV). As a common technique for parametric monitoring, trace slicing divides an execution trace into a set of sub traces which are checked against non-parametric base properties. An efficient trace slicing algorithm is implemented in MOP. Another RV technique, QEA further allows for nested use of universal and existential quantification over parameters. In this paper, we present a methodology for parametric monitoring using the RV framework SMEDL. Trace slicing algorithm in MOP can be expressed by execution of a set of SMEDL monitors. Moreover, the semantics of nested quantifiers is encoded by a hierarchy of monitors for aggregating verdicts of sub traces. Through case studies, we demonstrate that SMEDL provides a natural way to monitor parametric properties with more potentials for flexible deployment and optimizations

Telemedicine and Healthcare Implications for Central Virginia: A Systematic Review of the Literature

Background: Uncertainties and challenges associated with COVID-19 have affected the efficient delivery of health care in Central Virginia. Integrating and redesigning health systems could boost the quality and efficiency of care delivery. Telemedicine has been suggested as a viable solution to increase virtual access to patient advocacy healthcare education and training programs and has the potential to help facilitate the delivery of health services to rural and remote areas. It is projected that access to quality telehealth services can minimize the need for in-person hospital visitation amid the pandemic. The innovation also facilitates remote assessment of patients and monitoring of patient illness and treatment. For the rural population at risk of COVID-19 or any easily transmissible infection, telemedicine can provide convenient access to routine care without provider-patient contact, thus limiting the spread of the virus. Methods: A systematic literature review of peer-reviewed and grey literature was conducted. The authors used electronic databases including Embase, PubMed, CINAHIL and Web of Science to locate and access relevant articles based on their inclusion criteria. Studies were selected that investigated the implementation of telemedicine in the clinical and educational healthcare settings in rural or remote locations within the United States. Forty articles were identified for review. The identified articles were published between 2010 and 2021 that were used in the study. Results: There was no significant literature on telemedicine utilization in the Commonwealth of Virginia. Additionally, there were limited studies on rural and remote settings that utilized telehealth services during the COVID-19 pandemic. Evidence suggested that telemedicine could improve access to healthcare services and enable providers to monitor patients from a distance. Researchers identified six key factors associated with telemedicine\u27s success and sustainability: education, training, vision, ownership, adaptability, economics, efficiency, and equipment. Conclusions: Rural and remote communities experience healthcare disparities and poor patient outcomes due to limited access to quality care and inequalities in education, training, and resource allocation. A deficiency of technological skills, knowledge and or resistance to change may prevent a quality telehealth program from being able to serve patients adequately

An Experimental Study of Combustor Exit Profile Shapes on Endwall Heat Transfer in High Pressure Turbine Vanes

The design and development of current and future gas turbine engines for aircraft propulsio

An Experimental Study of Combustor Exit Profile Shapes on Endwall Heat Transfer in High Pressure Turbine Vanes

ABSTRACT The design and development of current and future gas turbine engines for aircraft propulsion have focused on operating the high pressure turbine at increasingly elevated temperatures and pressures. The drive towards thermal operating conditions near theoretical stoichiometric limits as well as increasingly stringent requirements on reducing harmful emissions, both equate to the temperature profiles exiting combustors and entering turbines becoming less peaked than in the past. This drive has placed emphasis on determining how different types of inlet temperature and pressure profiles affect the first stage airfoil endwalls. The goal of the current study was to investigate how different radial profiles of temperature and pressure affect the heat transfer along the vane endwall in a high pressure turbine. Testing was performed in the Turbine Research Facility located at the Air Force Research Laboratory using an inlet profile generator. Results indicate that the convection heat transfer coefficients are influenced by both the inlet pressure profile shape and the location along the endwall. The heat transfer driving temperature for inlet profiles that are nonuniform in temperature is also discussed. INTRODUCTION The performance and durability of the hot section within gas turbine engines are critical operational issues that present many design and research challenges. The hot section of these engines includes both the combustion chamber and the high pressure turbine, the latter of which includes the endwall regions under investigation in this study. Considering that the hot gas temperatures are well above the melting point of the metal turbine hardware, the heat transfer to and aerodynami