909 research outputs found
After the fall: globalizing the remnants of the Communist bloc
Globalization ; Europe, Eastern
Catastrophic vs Gradual Collapse of Thin-Walled Nanocrystalline Ni Hollow Cylinders As Building Blocks of Microlattice Structures
Lightweight yet stiff and strong lattice structures are attractive for various engineering applications, such as cores of sandwich shells and components designed for impact mitigation. Recent breakthroughs in manufacturing enable efficient fabrication of hierarchically architected microlattices, with dimensional control spanning seven orders of magnitude in length scale. These materials have the potential to exploit desirable nanoscale-size effects in a macroscopic structure, as long as their mechanical behavior at each appropriate scale â nano, micro, and macro levels â is properly understood. In this letter, we report the nanomechanical response of individual microlattice members. We show that hollow nanocrystalline Ni cylinders differing only in wall thicknesses, 500 and 150 nm, exhibit strikingly different collapse modes: the 500 nm sample collapses in a brittle manner, via a single strain burst, while the 150 nm sample shows a gradual collapse, via a series of small and discrete strain bursts. Further, compressive strength in 150 nm sample is 99.2% lower than predicted by shell buckling theory, likely due to localized buckling and fracture events observed during in situ compression experiments. We attribute this difference to the size-induced transition in deformation behavior, unique to nanoscale, and discuss it in the framework of âsize effectsâ in crystalline strength
Sustained obesity and depressive symptoms over 6 years: race by gender differences in the health and retirement study
Background: Although obesity and physical activity influence psychosocial well-being, these effects may vary based on race, gender, and their intersection. Using 6-year follow-up data of a nationally representative sample of adults over age of 50 in the United States, this study aimed to explore race by gender differences in effects of sustained high body mass index (BMI) and physical activity on continued depressive symptoms (CES-D) and self-rated health (SRH). Methods: Data came from waves 7, 8, and 10 (2004â2010) of the Health and Retirement Study (HRS), an ongoing national cohort started in 1992. The study enrolled a representative sample of Americans (n = 19,280) over the age of 50. Latent factors, sustained high BMI and physical activity (predictors) and sustained poor SRH and high depressive symptoms (outcomes), were calculated using the respective variable measurements in 2004, 2006, and 2010. Age, education, and income were included in the analysis as potential confounders. The two primary paths of interest in the current study were (1) the association between sustained high level of BMI and high depressive symptoms, and (2) the association between sustained high level of BMI and sustained poor SRH. Multi-group structural equation modeling (SEM) was used to test the effects of BMI and physical activity on depressive symptoms and SRH, where the groups were defined based on race by gender. Results: Group differences were apparent in the direction and significance of the association between sustained high BMI and depressive symptoms. The association between sustained high BMI and depressive symptoms was positive and significant for White women (B = 0.03, p = 0.007) and non-significant for White men (B = â0.03, p = 0.062), Black men (B = â0.02, p = 0.564) and Black women (B = 0.03, p = 0.110). No group differences were observed in the paths from sustained physical activity to depressive symptoms, or from physical activity or BMI to SRH. Conclusion: Sustained high BMI and high depressive symptoms after age 50 are significantly associated only for White women. As the association between sustained health problems such as depression and obesity are not universal across race and gender groups, clinical and public health programs that target multiple health problems may have differential effects across race by gender groups. The public health significance of this study is the importance of tailored interventions when addressing differential associations across groups
Traditional inequalities and inequalities of tradition: Gender, weddings and whiteness
The (British) white wedding offers a unique lens for studying a number of social and cultural phenomena from practices of intimacy, consumption and romance to macro level studies of economics, value and exchange. The wedding also represents an ideal focus for studying the intersection of intimacies and inequalities as it acts as a location for the practice and performance of intimacy which simultaneously encapsulates historical and contemporary gender, race and class inequalities. These inequalities are often upheld, celebrated even, in the name of âtraditionâ in relationships, marriage and weddings. This paper aims to interrogate this notion of tradition to understand how, rather than being a neutral concept, it is used to reproduce and reinforce existing gender inequalities, middle-class values and privileging of Whiteness. The argument in this paper draws on 3 years of research on weddings including interviews and ethnographic observations. I conclude that while wedding traditions may have become increasingly reflective of democratic choices, they retain traditional inequalities in their representation and conceptualisation
Practicalities of HCR-20 implementation within secure psychiatric services
The HCR-20 is established as the de-facto tool for the assessment of violence risk within forensic psychiatric services. Although much has been written about the value of the tool, less has been written about the practicalities of achieving meaningful completion of HCR-20 assessments at a service level. The present paper seeks to review recommendations within the literature and also those based upon the authorsâ own experiences in HCR-20 implementation, reviewing a number of the common issues and barriers encountered within the development of a strategic, service-level, approach to completion of the HCR-20. Possible solutions to these problems are also considered. We conclude that although there is not necessarily a single approach that is right for every service, certain principles need to be followed to ensure high quality assessments. Further, we develop a number of âgood practice pointsâ which will be useful for services considering this issue on a strategic level, as well as commissioners evaluating the quality of HCR-20 completion within services
Additive Manufacturing of Bioinspired Bulk Gradient Structures to Enhance Mechanical Performance
The research objective of this project is to investigate the effects of energy density-based
process parameters on the resulting mechanical properties of stainless steel 316L built by a
powder-bed additive manufacturing process. More specifically, we will to elucidate how the
volumetric energy density imparted by the laser as well as the energy deposition rate, affects the
hardness, porosity and density of the bulk material. For this, process parameters such as laser
power, and the variables constituting the effective scanning speed were changed, which
effectively alters the energy density imparted onto the material. By conducting a systematic
design of experiments, an understanding of the resolutions of properties achievable is obtained.
The resulting structures were tested for hardness, density measurements, and underwent
elemental analysis. By understanding the relationships of these mechanical properties as a
function of process energy density, it will be possible to create tailored spatial mechanical
property gradients. Bioinspired gradient structures can then be created and their mechanical
performance evaluated
Physical and Psychological Adjustments Associated with Home and Family Management Problems of Selected Normal and Handicapped Homemakers
The purpose of this study was to determine some physical and
psychological adjustments associated with home and family management
problems of homemakers.
The hypotheses formulated were: (1) There is no significant difference
between the experimental and control groups either in the number of responses
made or the intensity of attitude expressed toward physical disability, homemaker's
role, family life, or life in general; (2) there is no significant
difference between paired subjects with respect to their attitude toward
these aforementioned factors; and (3) there is no correlation between the
duration of the disability and attitudes expressed toward these identical
factors.
The experimental group consisted of ten physically-disabled homemakers,
while the control group was comprised of ten normal ones, all
between the ages of twenty and fifty.
Personal interviews and case studies were utilized to collect data
concerning physical and psychological adjustments of test subjects. Two
somewhat structured interviews were conducted in the home of each subject.
Data were tabulated and treated statistically.
Major findings indicate that: (1) The two groups did not differ in
intensity of attitude toward selected aspects of personal and family life;
(2) paired test subjects were not significantly different in their attitudes
toward selected aspects of personal and family life; and (3) disabled homemakers
related the duration of disability to attitudes toward their disability
and selected aspects of personal and family living.
Two conclusions were drawn, namely: (1) Those homemakers who
reflected the greatest insight into educational opportunities for the handicapped
tended to reflect better understanding of inherent problems and to
have more wholesome attitudes toward life in general, and (2) disabled
homemakers were approachable in terms of assistance needed to strengthen
management practices, and sought resources available to them.
In light of the findings and conclusions, the following implications
for further study are identified: (1) Experimental use of specifically
trained management aides to implement multiple-purpose programs to assist
disabled homemakers; (2) experimentation to provide maximum help to
families confronted with temporary disability; and (3) investigation to
test for specific changes in attitudes in light of given conditions.
This study points up the nature and extent of problems faced by
disabled homemakers and their interest and concern for specific professional
help in their day-to-day living experiences
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