Low-temperature solder for joining large cryogenic structures

Three joining methods were considered for use in fabricating cooling coils for the National Transonic Facility. After analysis and preliminary testing, soldering was chosen as the cooling coil joining technique over mechanical force fit and brazing techniques. Charpy V-Notch tests, cyclic thermal tests (ambient to 77.8 K) and tensile tests at cryogenic temperatures were performed on solder joints to evaluate their structural integrity. It was determined that low temperature solder can be used to ensure good fin-to-tube contact for cooling-coil applications

Apples and Oranges: An International Comparison of the Public's Experience of Justiciable Problems and the Methodological Issues Affecting Comparative Study

Since the mid-1990s, at least 28 large-scale national surveys of the public's experience of justiciable problems have been conducted in at least 15 separate jurisdictions, reflecting widespread legal aid reform activity. While the majority of these surveys take their structure from Genn's Paths to Justice survey (1999), they vary significantly in length, scope, mode of administration, types of problems included, survey reference period, data structure, data analysis, and question formulation. This article draws on surveys from across the world, contrasting their methodologies, comparing their headline findings, and setting out the potential for bias as a consequence of methodological variation. The article also presents findings from five online experiments testing the impact of various question formulations on problem prevalence, use of advice, and formal processes. Specifically, the experiments test whether varying the reference period, describing problems as “legal,” offering detailed as opposed to simple problem descriptions, and describing problems as “difficult to solve” had an impact on reported prevalence of justiciable problems, and whether presenting lists as opposed to a series of individual questions had an impact on reported use of advice and processes. The experiments demonstrated that modest differences in question formulation yield significantly different results. Specifically, alteration of survey reference period did not result in a proportional change in reported problem prevalence, introducing problems as either “legal” or “difficult to solve” significantly reduced reported prevalence, and introducing use of advice/processes as multiple questions rather than as lists significantly increased reported use. The risks involved in comparative analysis (and particularly in looking beyond methodology when attempting to explain jurisdictional variation) are discussed. In relation to future studies, the importance of understanding the impact of methodological change, learning the lessons of the past, making technical details transparent, and making data available are highlighted

Perioperative Medication Teaching Protocol: An Evidence-Based Project in a Perioperative Surgical Home

At the outpatient surgery center, there is a need for a perioperative medication guideline to improve appropriate medication teaching and compliance in the days and weeks leading up to a surgical intervention. It is critical that protocols and evidence-based guidelines are used throughout the management of all patients taking oral anticoagulants during the perioperative window. Currently, there is no standardized teaching protocol for patients preparing for surgery who are on anticoagulants. This lack of standardization could lead to increased surgical complications. Patient education is essential to preoperative optimization and can lead to improved patient compliance. This can be done by streamlining the education given to patients regarding their perioperative anticoagulant management, which increases effectiveness of the education and decrease adverse reactions. One solution, and the focus of this project, will be implementing a standardized medication teaching protocol, via the perioperative surgical home, to improve appropriate adherence in patients taking anticoagulants. The aim of the proposed project is that by May 30, 2021, 100% of perioperative nursing staff will receive the preoperative medication guideline, participate in the educational training, and demonstrate competency in knowledge of the guideline and patient education

Braze alloy process and strength characterization studies for 18 nickel grade 200 maraging steel with application to wind tunnel models

A comprehensive study of braze alloy selection process and strength characterization with application to wind tunnel models is presented. The applications for this study include the installation of stainless steel pressure tubing in model airfoil sections make of 18 Ni 200 grade maraging steel and the joining of wing structural components by brazing. Acceptable braze alloys for these applications are identified along with process, thermal braze cycle data, and thermal management procedures. Shear specimens are used to evaluate comparative shear strength properties for the various alloys at both room and cryogenic (-300 F) temperatures and include the effects of electroless nickel plating. Nickel plating was found to significantly enhance both the wetability and strength properties for the various braze alloys studied. The data are provided for use in selecting braze alloys for use with 18 Ni grade 200 steel in the design of wind tunnel models to be tested in an ambient or cryogenic environment

Lighting the fuse: Cultivating the masculine physics habitus – a case study of Victor aged 10-18

This chapter presents a longitudinal case study analysis of Victor, a young man who was interviewed from the ages of 10–19, together with his mother, Sam, and who went on to study for a degree in astrophysics. We apply a Bourdieusian conceptual lens to the data, to explore how interactions of capital, habitus and field combine to possibilise Victor and his trajectory to being/becoming a physicist. We also identify specific alignments of his habitus and capital with dominant notions of masculinity and ‘cleverness’ that are demanded and normalised within physics and which, we argue, are key to the reproduction of the elite nature of physics

Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence

<p>Abstract</p> <p>Background</p> <p>People with diabetes can suffer from diverse complications that seriously erode quality of life. Diabetes, costing the United States more than $174 billion per year in 2007, is expected to take an increasingly large financial toll in subsequent years. Accurate projections of diabetes burden are essential to policymakers planning for future health care needs and costs.</p> <p>Methods</p> <p>Using data on prediabetes and diabetes prevalence in the United States, forecasted incidence, and current US Census projections of mortality and migration, the authors constructed a series of dynamic models employing systems of difference equations to project the future burden of diabetes among US adults. A three-state model partitions the US population into no diabetes, undiagnosed diabetes, and diagnosed diabetes. A four-state model divides the state of "no diabetes" into high-risk (prediabetes) and low-risk (normal glucose) states. A five-state model incorporates an intervention designed to prevent or delay diabetes in adults at high risk.</p> <p>Results</p> <p>The authors project that annual diagnosed diabetes incidence (new cases) will increase from about 8 cases per 1,000 in 2008 to about 15 in 2050. Assuming low incidence and relatively high diabetes mortality, total diabetes prevalence (diagnosed and undiagnosed cases) is projected to increase from 14% in 2010 to 21% of the US adult population by 2050. However, if recent increases in diabetes incidence continue and diabetes mortality is relatively low, prevalence will increase to 33% by 2050. A middle-ground scenario projects a prevalence of 25% to 28% by 2050. Intervention can reduce, but not eliminate, increases in diabetes prevalence.</p> <p>Conclusions</p> <p>These projected increases are largely attributable to the aging of the US population, increasing numbers of members of higher-risk minority groups in the population, and people with diabetes living longer. Effective strategies will need to be undertaken to moderate the impact of these factors on national diabetes burden. Our analysis suggests that widespread implementation of reasonably effective preventive interventions focused on high-risk subgroups of the population can considerably reduce, but not eliminate, future increases in diabetes prevalence.</p

Entry, Exit, and the Determinants of Market Structure

This paper estimates a dynamic, structural model of entry and exit in an oligopolistic industry and uses it to quantify the determinants of market structure and long-run firm values for two U.S. service industries, dentists and chiropractors. Entry costs faced by potential entrants, fixed costs faced by incumbent producers, and the toughness of short-run price competition are all found to be important determinants of long-run firm values, firm turnover, and market structure. Estimates for the dentist industry allow the entry cost to differ for geographic markets that were designated as Health Professional Shortage Areas and in which entry was subsidized. The estimated mean entry cost is 11 percent lower in these markets. Using simulations, we compare entry-cost versus fixed-cost subsidies and find that entry-cost subsidies are less expensive per additional firm

Legal Empowerment and Horizontal Inequalities after Conflict

This article explores whether legal empowerment can address horizontal inequalities in post-conflict settings, and, if so, how. It argues that legal empowerment has modest potential to reduce these inequalities. Nevertheless, there are risks that legal empowerment might contribute to a strengthening of group identities, reduction of social cohesion, and, in the worst case, triggering of conflict. It looks at how two legal empowerment programmes in Liberia navigated the tensions between equity and peace

Self-Selection in Migration and Returns to Unobservable Skills

Several papers have tested the empirical validity of the migration models proposed by Borjas (1987) and Borjas, Bronars, and Trejo (1992). However, to our knowledge, none has been able to disentangle the separate impact of observable and unobservable individual characteristics, and their respective returns across different locations, on an individual's decision to migrate. We build a model in which individuals sort, in part, on potential earnings - where earnings across different locations are a function of both observable and unobservable characteristics. We focus on the inter-provincial migration patterns of Canadian physicians. We choose this particular group for several reasons including the fact that they are paid on a fee-for-service basis. Since wage rates are exogenous, earning differentials are driven by differences in productivity. We then estimate a mixed conditional-logit model to determine the effects of individual and destination-specific characteristics (particularly earnings differentials) on physician location decisions. We find, among other things, that high-productivity physicians (based on unobservables) are more likely to migrate to provinces where the productivity premium is greater, while low-productivity physicians are more likely to migrate to areas where the productivity premium is lower. These results are consistent with a modified Borjas model of self-selection in migration based on both unobservables and observables

Correlates of Out-of-Pocket and Catastrophic Health Expenditures in Tanzania: Results from a National Household Survey.

Inequality in health services access and utilization are influenced by out-of-pocket health expenditures in many low and middle-income countries (LMICs). Various antecedents such as social factors, poor health and economic factors are proposed to direct the choice of health care service use and incurring out-of-pocket payments. We investigated the association of these factors with out-of-pocket health expenditures among the adult and older population in the United Republic of Tanzania. We also investigated the prevalence and associated determinants contributing to household catastrophic health expenditures. We accessed the data of a multistage stratified random sample of 7279 adult participants, aged between 18 and 59 years, as well as 1018 participants aged above 60 years, from the first round of the Tanzania National Panel survey. We employed multiple generalized linear and logistic regression models to evaluate the correlates of out-of-pocket as well as catastrophic health expenditures, accounting for the complex sample design effects. Increasing age, female gender, obesity and functional disability increased the adults' out-of-pocket health expenditures significantly, while functional disability and visits to traditional healers increased the out-of-pocket health expenditures in older participants. Adult participants, who lacked formal education or worked as manual laborers earned significantly less (p < 0.001) and spent less on health (p < 0.001), despite having higher levels of disability. Large household size, household head's occupation as a manual laborer, household member with chronic illness, domestic violence against women and traditional healer's visits were significantly associated with high catastrophic health expenditures. We observed that the prevalence of inequalities in socioeconomic factors played a significant role in determining the nature of both out-of-pocket and catastrophic health expenditures. We propose that investment in social welfare programs and strengthening the social security mechanisms could reduce the financial burden in United Republic of Tanzania