Probabilistic Estimation of Critical Flaw Sizes in the Primary Structure Welds of the Ares I-X Launch Vehicle

The primary structure of the Ares I-X Upper Stage Simulator (USS) launch vehicle is constructed of welded mild steel plates. There is some concern over the possibility of structural failure due to welding flaws. It was considered critical to quantify the impact of uncertainties in residual stress, material porosity, applied loads, and material and crack growth properties on the reliability of the welds during its pre-flight and flight. A criterion--an existing maximum size crack at the weld toe must be smaller than the maximum allowable flaw size--was established to estimate the reliability of the welds. A spectrum of maximum allowable flaw sizes was developed for different possible combinations of all of the above listed variables by performing probabilistic crack growth analyses using the ANSYS finite element analysis code in conjunction with the NASGRO crack growth code. Two alternative methods were used to account for residual stresses: (1) The mean residual stress was assumed to be 41 ksi and a limit was set on the net section flow stress during crack propagation. The critical flaw size was determined by parametrically increasing the initial flaw size and detecting if this limit was exceeded during four complete flight cycles, and (2) The mean residual stress was assumed to be 49.6 ksi (the parent material s yield strength) and the net section flow stress limit was ignored. The critical flaw size was determined by parametrically increasing the initial flaw size and detecting if catastrophic crack growth occurred during four complete flight cycles. Both surface-crack models and through-crack models were utilized to characterize cracks in the weld toe

The prevalence of common mental disorders and PTSD in the UK military: using data from a clinical interview-based study

<p>Abstract</p> <p>Background</p> <p>The mental health of the Armed Forces is an important issue of both academic and public interest. The aims of this study are to: a) assess the prevalence and risk factors for common mental disorders and post traumatic stress disorder (PTSD) symptoms, during the main fighting period of the Iraq War (TELIC 1) and later deployments to Iraq or elsewhere and enlistment status (regular or reserve), and b) compare the prevalence of depression, PTSD symptoms and suicidal ideation in regular and reserve UK Army personnel who deployed to Iraq with their US counterparts.</p> <p>Methods</p> <p>Participants were drawn from a large UK military health study using a standard two phase survey technique stratified by deployment status and engagement type. Participants undertook a structured telephone interview including the Patient Health Questionnaire (PHQ) and a short measure of PTSD (Primary Care PTSD, PC-PTSD). The response rate was 76% (821 participants).</p> <p>Results</p> <p>The weighted prevalence of common mental disorders and PTSD symptoms was 27.2% and 4.8%, respectively. The most common diagnoses were alcohol abuse (18.0%) and neurotic disorders (13.5%). There was no health effect of deploying for regular personnel, but an increased risk of PTSD for reservists who deployed to Iraq and other recent deployments compared to reservists who did not deploy. The prevalence of depression, PTSD symptoms and subjective poor health were similar between regular US and UK Iraq combatants.</p> <p>Conclusion</p> <p>The most common mental disorders in the UK military are alcohol abuse and neurotic disorders. The prevalence of PTSD symptoms remains low in the UK military, but reservists are at greater risk of psychiatric injury than regular personnel.</p

The return of the fifties: Trends in college students' values between 1952 and 1984

Five identical surveys were carried out in 1952, 1968–1969, 1974, 1979, and 1984 among undergraduate men at Dartmouth College and the University of Michigan to measure value trends. In most value domains the trends are U-shaped, showing that the trends from the fifties to the sixties and seventies have reversed, and attitudes in 1984 were either similar to the fifties or moving in that direction. The domains include traditional religion, career choice, faith in government and the military, advocacy of social constraints on deviant social groups, attitudes about free enterprise, government and economics, sexual morality, marijuana use, and personal moral obligations. Two attitude areas do not show a return of the fifties: (1) other-direction was high in 1952, then dropped to the sixties and did not rise; (2) the level of politicization rose greatly from 1952 to the sixties, then dropped again only slightly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45659/1/11206_2005_Article_BF01106623.pd

Framing Homeless Policy: Reducing Cash Aid as a Compassionate Solution

In 2002, Care Not Cash/Proposition N was introduced to respond to public concern over San Francisco’s chronic homeless epidemic. The controversial initiative, which significantly reduced General Assistance (cash aid) to unhoused people, diverted funds to direct services such as shelter, food, medical assistance, and substance abuse programs. To investigate the underlying attitudes and beliefs that framed homelessness and the Care Not Cash policy in the months leading up to the citywide vote articles from the San Francisco Chronicle were analyzed. Of particular interest was assessing the prevalence of individualistic framing, constructions of dependency, and the problems Care Not Cash was presented as solving. Our analysis found that homelessness was framed as a threat to businesses, tourism, and residents of San Francisco and welfare as enabling deviant behavior (e.g., substance abuse) among people experiencing homelessness. Similar to federal welfare reform, Care Not Cash was portrayed as a compassionate solution that would both solve the problem of homelessness and address problematic behaviors associated with people who are unhoused (Stryker & Wald, 2009). Implications for economic justice are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147013/1/asap12156_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147013/2/asap12156.pd

Effect of CGRP and sumatriptan on the BOLD response in visual cortex

To test the hypothesis that calcitonin gene-related peptide (CGRP) modulates brain activity, we investigated the effect of intravenous CGRP on brain activity in response to a visual stimulus. In addition, we examined if possible alteration in brain activity was reversed by the anti-migraine drug sumatriptan. Eighteen healthy volunteers were randomly allocated to receive CGRP infusion (1.5 μg/min for 20 min) or placebo. In vivo activity in the visual cortex was recorded before, during and after infusion and after 6 mg subcutaneous sumatriptan by functional magnetic resonance imaging (3 T). 77% of the participants reported headache after CGRP. We found no changes in brain activity after CGRP (P = 0.12) or after placebo (P = 0.41). Sumatriptan did not affect brain activity after CGRP (P = 0.71) or after placebo (P = 0.98). Systemic CGRP or sumatriptan has no direct effects on the BOLD activity in visual cortex. This suggests that in healthy volunteers both CGRP and sumatriptan may exert their actions outside of the blood–brain barrier

New Mechanics of Traumatic Brain Injury

The prediction and prevention of traumatic brain injury is a very important aspect of preventive medical science. This paper proposes a new coupled loading-rate hypothesis for the traumatic brain injury (TBI), which states that the main cause of the TBI is an external Euclidean jolt, or SE(3)-jolt, an impulsive loading that strikes the head in several coupled degrees-of-freedom simultaneously. To show this, based on the previously defined covariant force law, we formulate the coupled Newton-Euler dynamics of brain's micro-motions within the cerebrospinal fluid and derive from it the coupled SE(3)-jolt dynamics. The SE(3)-jolt is a cause of the TBI in two forms of brain's rapid discontinuous deformations: translational dislocations and rotational disclinations. Brain's dislocations and disclinations, caused by the SE(3)-jolt, are described using the Cosserat multipolar viscoelastic continuum brain model. Keywords: Traumatic brain injuries, coupled loading-rate hypothesis, Euclidean jolt, coupled Newton-Euler dynamics, brain's dislocations and disclinationsComment: 18 pages, 1 figure, Late

Risk Factors for Posttraumatic Stress Disorder Among Deployed US Male Marines

<p>Abstract</p> <p>Background</p> <p>Combat exposure has been reported as one of the strongest risk factors for postdeployment posttraumatic stress disorder (PTSD) among military service members. Determining the impact of specific deployment-related exposures on the risk of developing PTSD has not been fully explored. Our study objective was to explore the relationship between specific combat exposures and other life experiences with postdeployment PTSD.</p> <p>Methods</p> <p>This study consisted of male Marines who completed a Recruit Assessment Program (RAP) survey during recruit training at the Marine Corps Recruit Depot in San Diego, California as well as a follow-up survey several years after recruit training. Study participants included those Marines who deployed to the current operations in Iraq or Afghanistan between the baseline and follow-up surveys. Multivariable logistic regression was performed to determine which significant exposures and experiences were associated with postdeployment PTSD.</p> <p>Results</p> <p>Of the 706 study participants, 10.8% screened positive for postdeployment PTSD. Those who reported feeling in great danger of death (odds ratio [OR] = 4.63, 95% confidence interval [CI]: 2.46-8.73), were shot or seriously injured (OR = 3.51, 95% CI: 1.58-7.77), saw someone wounded or killed (OR = 2.47, 95% CI: 1.08-5.67), and baseline (before recruit training) prior violence exposures (OR = 2.99, 95% CI: 1.46-6.10) were at increased odds for reporting PTSD symptoms. Number of deployments, number of close friends or relatives reported at follow-up, and enlisted pay grade were also significantly associated with postdeployment PTSD.</p> <p>Conclusions</p> <p>Combat exposures, specifically the threat of death, serious injury, and witnessing injury or death are significant risk factors for screening positive for postdeployment PTSD among male Marines as well as violence exposures prior to entering the Marine Corps, which are independent of future combat exposures. A thorough history of lifetime violence exposures should be pursued when considering a clinical diagnosis of PTSD.</p

Children and Their Parents: A Comparative Study of the Legal Position of Children with Regard to Their Intentional and Biological Parents in English and Dutch Law

This is a book about children and their parents. There are many different kinds of children and at least about as many different kinds of parents. In addition to the many different disciplines that study children and their parents, such as sociology, psychology, child studies and gender studies, to name but a few, this study concerns a legal question with regard to the parent-child relationship, namely how the law assigns parents to children. This subject is approached in a comparative legal perspective and covers England and The Netherlands. The book contains a detailed comparison and analysis of the manner in which the law in the two jurisdictions assigns the status of legal parent and/or attributes parental responsibility to the child’s biological and intentional parents. The concept ‘procreational responsibility’, which is introduced in the concluding chapter of the book, may be used as a tool to assess and reform existing regulations on legal parent-child relationships. The structure of the book, which is based on a categorisation of different family types in a ‘family tree’, enables the reader to have easy access to family-specific information.FdR – Publicaties zonder aanstelling Universiteit Leide