Structural Behavior of Inflatable, Reinforced, Braided, Tubular Members

The Hypersonic Inflatable Aerodynamic Decelerator (HIAD) system being developed by the National Aeronautics and Space Administration (NASA) is an inflatable structure composed of multiple, concentric, pressurized tori, load straps, and a thermal protection system. The HIAD overcomes limitations inherent with the use of rigid decelerators since the deployed diameter is much larger than the packed size, which makes it an enabling technology for new opportunities in space exploration. The HIAD is designed to decelerate and protect spacecraft during atmospheric re-entry. The objective of this research was to improve understanding of structural behavior of HIAD components through material testing, structural testing of components, and numerical models. The mechanics of inflatable, reinforced braided tubes have been reviewed from a geometric standpoint. Exploratory experimental efforts were performed to quantify the stiffness of the reinforcing cords, which drive axial and bending stiffness of the inflatable tubes. Benchtop inflation tests were performed to quantify longitudinal stiffness and examine instrumentation methods. The constitutive properties of the braided fabric shell of tori were determined as a function of braid angle and inflation pressure. The shear modulus is highly dependent on braid angle and pressure. Independent testing of extracted fiber tow bundles allowed the effect of de-crimping to be examined with straight tow thickness measured as an upper limit. Beam bending tests of straight beams with highly controlled loading and boundary conditions were performed for tubes with five different braid angles over a range of inflation pressures. These data sets are ideal for finite element validation due to the highly controlled conditions. Structural testing of individual tori was performed via radial compression loading. Many improvements were made to the single torus test setup using fixtures provided by NASA. Methods were developed to quantify the 3D shape of the tori and displacements using non-contact photogrammetry methods. The effect of load-control versus displacement-control experiments was investigated and found to result in different response. Finite-element models using three-dimensional shell-elements were developed and compared to the torus experiments. These modeling efforts proved to be challenging and no firm conclusions could be drawn

The Driving Behavior Survey: scale construction and validation.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.Although long recognized in the clinical literature, problematic behavior characteristic of anxious drivers has received little empirical attention. The current research details development of a measure of anxious driving behavior conducted across three studies. Factor analytic techniques identified three dimensions of maladaptive behaviors across three college samples: anxiety-based performance deficits, exaggerated safety/caution behavior, and anxiety-related hostile/aggressive behavior. Performance deficits evidenced convergent associations with perceived driving skill and were broadly related to driving fear. Safety/caution behaviors demonstrated convergence with overt travel avoidance, although this relationship was inconsistent across studies. Safety/caution scores were associated specifically with accident- and social-related driving fears. Hostile/aggressive behaviors evidenced convergent relationships with driving anger and were associated specifically with accident-related fear. Internal consistencies were adequate, although some test-retest reliabilities were marginal in the unselected college sample. These data provide preliminary evidence for utility of the measure for both research and clinical practice

Does Proximity to Retailers Influence Alcohol and Tobacco Use Among Latino Adolescents?

Despite decades of research surrounding determinants of alcohol and tobacco (A&T) use among adolescents, built environment influences have only recently been explored. This study used ordinal regression on 205 Latino adolescents to explore the influence of the built environment (proximity to A&T retailers) on A&T use, while controlling for recognized social predictors. The sample was 45% foreign-born. A&T use was associated with distance from respondents’ home to the nearest A&T retailer (−), acculturation (+), parents’ consistent use of contingency management (−), peer use of A&T (+), skipping school (+), attending school in immediate proximity to the US/Mexico border (+), and the interaction between the distance to the nearest retailer and parents’ consistent use of contingency management (+). The association between decreasing distance to the nearest A&T retailer and increased A&T use in Latino adolescents reveals an additional risk behavior determinant in the US–Mexico border region

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

William J. Clapp attorney dockets, 1921-1934.

W.J. Clapp’s Attorney’s Dockets cover the period 1921-1934. They include an alphabetical list of clients; details of cases such as foreclosures and wills; and many newspaper clippings related to the cases

Analysis of Rutting Development in Flexible Pavements with Geogrid-reinforced Base Layers Using 3D Finite Element Analysis

Geogrid can provide the base layers of flexible asphalt pavements with tensile strength, which may ultimately lead to improvements in rutting behavior. Significant experimental and finite element-based research has been conducted in the recent past to examine the benefits of geogrid reinforcement. The benefits are well established for relatively thin pavement sections, but inconclusive results have been reported for relatively thick pavement sections. The objective of this study was to develop a method of quantifying the rutting performance improvements associated with geogrid in a variety of relatively thick pavement sections. A three-dimensional finite element model was developed to simulate the response of relatively thick flexible pavement sections with geogrid-reinforced base layers. Data from extensively instrumented test sections was used to calibrate the model. The model was capable of accurately predicting strains in the asphalt, base, and subgrade layers, as well as in the geogrid reinforcement. Optimal soil layer moduli were determined to be close to average values obtained through FWD testing. Conventional accepted permanent deformation models were modified in this study to reflect the improvements in pavement response associated with geogrid reinforcement. The permanent deformation models were calibrated using strains from the FE model and measured permanent deformations in individual material layers from three test sections. The permanent deformation models were capable of reasonably predicting the response of pavement sections that include varying asphalt layer thickness and the presence of reinforcement. The permanent deformation models were limited to a base layer thickness of 300mm. A parametric study was conducted to examine the predicted benefits of geogrid reinforcement with varying asphalt modulus, base modulus, subgrade modulus, asphalt thickness, and location of geogrid within base layer. Unreinforced models were also examined for comparison. It was found that geogrid is relatively more effective in pavement sections with larger asphalt moduli, lower base moduli, lower subgrade moduli, and thinner asphalt layers. The optimal location of the geogrid was always predicted to be at the bottom of the base layer. General conclusions agree with the results from prior studies. Geogrid is predicted to offer significant benefits to pavement sections with asphalt thickness up to 200mm (8in) and base layer thickness of 300mm (12in). It is recommended that future work should investigate the use of nonlinear material models. Data from the remaining test sections in this study should be used to recalibrate the permanent deformation models in order to consider the effect of increased base layer thickness up to 600mm (24in). The effect of geogrid location within relatively thick base layers should be further investigated

A different kind of comorbidity: Understanding posttraumatic stress disorder and chronic pain.

Many traumatic events leave lingering physical injuries and chronic pain in their wake, in addition to trauma-related psychopathology. In this review, we provide an overview of developments in the recent literature on comorbid posttraumatic stress disorder (PTSD) and chronic pain. Starting with the conceptual models presented by Sharp and Harvey (2001) and Asmundson, Coons, Taylor, and Klatz (2002), this review summarizes newer studies that examine prevalence of these comorbid conditions. Additionally, we present an updated synthesis of research on factors that may maintain both chronic physical pain and PTSD in trauma survivors. Consideration of the impact of this comorbidity on psychosocial assessment and treatment also is discussed, with particular attention to issues that warrant additional research. © 2011 American Psychological Association

Treatment of PTSD in Older Adults: Do Cognitive-Behavioral Interventions Remain Viable?

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An Examination of the Glover Numbing Scale: Expanding the Content Validity of Posttraumatic Numbing

Quantification of posttraumatic numbing (PTN) has largely been limited to the assessment of a small number of items taken directly from the DSM. The current study takes steps to expand the content validity of PTN through examination of the Glover Numbing Scale (GNS), one of the few available measures specific to PTN. Specifically, the factor structure of the GNS and its convergence with DSM-based indices of PTN were examined in a sample of motor vehicle accident survivors (MVA; N∈=∈288). Whereas the 5-factor structure originally proposed by Glover et al. Anxiety 1:70-79 (1994) evidenced a poor fit to the sample data, exploratory analysis suggested a 1-factor structure underlying data collected from the sample. Furthermore, GNS scores derived from this solution evidenced a strong convergent relationship with DSM-based PTN. These data suggest that alternative indicators contained within the GNS may be used to expand current conceptualizations of PTN. © 2008 Springer Science+Business Media, LLC