453 research outputs found

    Effect of the foam embellishments on the pedestrian safety of the vehicle front protection systems

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    Pedestrian safety related compliance requirements are very important in case of design and development of the vehicle front protection systems. Computer aided engineering impact simulations were carried out to evaluate Head Injury Criterion (HIC) of a typical bullbar impacting it with an adult headform and correlated with experimental results. Impact simulations were carried out on the same bullbar covered with semi‐rigid polyurethane foam to study the effect of foam embellishments on the pedestrian safety. Results obtained from the impact simulations were presented in this paper

    Magnetocaloric effect and improved relative cooling power in (La0.7Sr0.3MnO3/SrRuO3) superlattices

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    Magnetic properties of a series of (La0.7Sr0.3MnO3/SrRuO3) superlattices, where the SrRuO3 layer thickness is varying, are examined. A room-temperature magnetocaloric effect is obtained owing to the finite size effect which reduces the TC of La0.7Sr0.3MnO3 layers. While the working temperature ranges are enlarged,, -DeltaSmax values remains similar to the values in polycrystalline La0.7Sr0.3MnO3. Consequently, the relative cooling powers are significantly improved, the microscopic mechanism of which is related to the effect of the interfaces at La0.7Sr0.3MnO3/SrRuO3 and higher nanostructural disorder. This study indicates that artificial oxide superlattices/multilayers might provide an alternative pathway in searching for efficient room-temperature magnetic refrigerators for (nano)microscale systems.Comment: 14^pages, 3 figures, Submitted to J. Phys. Cond. Ma

    Evaluation of the blunt thoracic trauma due to baseball impacts – review of the Blunt Criterion

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    Evaluation of the thoracic injury due to blunt impacts during the contact and collision sports activity is crucial for the development and validation of the chest protectors and safety solid sports for the athletes. In the case of young athletes, proper chest protectors can avoid not only severe chest trauma but also protect them from the sudden death due to commotio-cordis. In order to evaluate the thoracic injury in terms of known engineering parameters (Viscous Criterion), non-linear finite element simulations were carried out by impacting FE model of the thorax surrogate (MTHOTA- Mechanical THOrax for Trauma Assessment) with a synthetic baseball and a synthetic baseball of the same size and weight at the impact speed of 10 – 45 m/s (with an increment of 5 m/s). Synthetic baseball and soft-core baseball produced VCmax = 1 m/s at the impact speed of 27.9 m/s and 30.7 m/s respectively. For both sports ball impact cases, Blunt Criterion (which is commonly used as non-lethal munitions design criterion that takes only kinetic energy of the projectile and weight & geometry of the thorax into consideration) was evaluated for all impact cases of two types of baseballs. Results have revealed the projectile specificity of the Blunt Criterion

    Review of anthropomorphic test dummies for the evaluation of thoracic trauma due to blunt ballistic impacts

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    Biomechanical responses of the thoraces of finite element models of 4 Anthropomorphic Test Dummies (namely, LSTC Hybrid III deformable, LSTC Hybrid III rigid, LSTC/NCAC Hybrid III and ES-2re) were reviewed by impacting them with the 140 gram wooden projectile with impact speeds of 20 and 40 m/s, and 30 g wooden projectile with 60 m/s. In order to elucidate the usefulness of the ATDs for evaluating blunt thoracic trauma caused by blunt ballistic impacts (projectile mass 20 – 200 gram, velocity 20 – 250 m/s), responses obtained were compared with the human response corridors developed by Wayne State University’s researchers. It was evident that none of the thoraces exhibited bio-fidelity for the impact cases considered for the analysis. Thoraces of former three dummies found to be very stiff and the latter yielded realistic responses but Viscous Criterion (VCmax) values based on the deflection response were way higher when compared to those obtained from the cadaveric experiments for the similar impact conditions. Values of viscous criterion (VCmax), probability for AIS3+ and AIS4+ injuries based on the maximum rib deflections (only for the ES-2re dummy for particular impact locations), were found to be, for some cases, to a certain extent, in agreement with those obtained from the cadaveric experiments. The present study highlights the unsuitability of the numerous thorax models (both physical and finite element), while necessitating the development of the thorax surrogate with an acceptable biofidelity. Such biomechanical surrogate of the thorax, for the evaluation of trauma, is essential for the validation of non-lethal ammunition, development of bullet proof vests and chest protectors for the athletes of collision & contact sports

    Male Grooming: An Ethnographic Research on Perception and Choice of Male Cosmetics

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    The purpose of this study is to explore male perceptions toward cosmetics and their product choice. Applying an ethnographic framework to this study, three males between the ages of 24-30 were interviewed through a series of 141 questions pertaining to their demographics, lifestyle, attitudes toward masculinity, skin care, grooming and cleaning behaviors. The results showed five overarching themes: (1) all of the participants had early experiences with personal care products, (2) the term masculinity was defined with terms such as calm and practical , (3) all participants looked up to their fathers as their key role models, (4) all participants valued loyal friendships, and (5) location convenience drives shopping for cosmetics - participants tend to only shop for cosmetics at a location where they are based at any given point in time, thereby implying an unwillingness to travel to a specialty store for purchasing grooming items. Managerial implications utilizing the results of this research are also discussed

    Numerical continuation analysis of a dual-sidestay main landing gear mechanism

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    A model of a three-dimensional dual-sidestay landing gear mechanism is presented and employed in an investigation of the sensitivity of the downlocking mechanism to attachment point deflections. A motivation for this study is the desire to understand the underlying nonlinear behavior, which may prevent a dual-sidestay landing gear from downlocking under certain conditions. The model formulates the mechanism as a set of steady-state constraint equations. Solutions to these equations are then continued numerically in state and parameter space, providing all state parameter dependencies within the model from a single computation. The capability of this analysis approach is demonstrated with an investigation into the effects of the aft sidestay angle on retraction actuator loads. It was found that the retraction loads are not significantly affected by the sidestay plane angle, but the landing gear’s ability to be retracted fully is impeded at certain sidestay plane angles. This result is attributed to the landing gear’s geometry, as the locklinks are placed under tension and cause the mechanism to lock. Sidestay flexibilities and attachment point deflections are then introduced to enable the downlock loads to be investigated. The investigation into the dual sidestay’s downlock sensitivity to attachment point deflections yields an underlying double-hysteresis loop, which is highly sensitive to these deflections. Attachment point deflections of a few millimeters were found to prevent the locklinks from automatically downlocking under their own weight, hence requiring some external force to downlock the landing gear. Sidestay stiffness was also found to influence the downlock loads, although not to the extent of attachment point deflection

    Insulin resistance and endometrial cancer risk: A systematic review and meta-analysis

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    Abstract Aim: It has been suggested that chronic hyperinsulinemia from insulin resistance is involved in the etiology of endometrial cancer (EC). We performed a systematic review and meta-analysis to assess whether insulin resistance is associated with the risk of EC. Methods: We searched PubMed-Medline, Embase, Scopus, and Web of Science for articles published from database inception through 30th September 2014. We included all observational studies evaluating components defining insulin resistance in women with and without EC. Quality of the included studies was assessed by NewcastleeOttawa scale. Randomeffects models and inverse variance method were used to meta-analyze the association between insulin resistance components and EC. Results: Twenty-five studies satisfied our inclusion criteria. Fasting insulin levels (13 studies, n Z 4088) were higher in women with EC (mean difference [MD] 33.94 pmol/L, 95% confi- dence interval [CI] 15.04e52.85, p Z 0.0004). No differences were seen in postmenopausal versus pre- and postmenopausal subgroup analysis. Similarly, non-fasting/fasting C-peptide levels (five studies, n Z 1938) were also higher in women with EC (MD 0.14 nmol/L, 95% CI 0.08e0.21, p < 0.00001). Homeostatic model assessment - insulin resistance (HOMA-IR) values (six studies, n Z 1859) in EC patients were significantly higher than in women without EC (MD 1.13, 95% CI 0.20e2.06, p Z 0.02). There was moderate-to-high heterogeneity among the included studies. Conclusion: Currently available epidemiologic evidence is suggestive of significantly higher risk of EC in women with high fasting insulin, non-fasting/fasting C-peptide and HOMAIR values.Revisión por pare

    Association of plasma neurofilament light chain with glycaemic control and insulin resistance in middle-aged adults

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    Aims: This study aimed to determine the association of plasma neurofilament light (NfL), a marker of neurodegeneration, with diabetes status and glycaemic parameters in people with normal glycaemia (NG), pre-diabetes (PD) and type 2 diabetes (T2D). Methods: Clinical and descriptive data for the diagnostic groups, NG (n=30), PD (n=48) and T2D (n=29), aged between 40 and 75 years were included in this cross-sectional analysis. Plasma NfL levels were analyzed using the ultra-sensitive single-molecule array (Simoa) platform. Results: A positive correlation was evident between plasma NfL and fasting glucose (r = 0.2824; p = 0.0032). Plasma NfL levels were not correlated with fasting insulin and insulin resistance. Plasma Nfl levels were significantly different across the diabetes groups (T2D \u3e PD \u3e NG, p = 0.0046). Post-hoc analysis indicated significantly higher plasma NfL levels in the T2D [12.4 (5.21) pg/mL] group than in the PD [10.2 (4.13) pg/mL] and NG [8.37 (5.65) pg/mL] groups. The relationship between diabetes status and NfL remained significant after adjusting for age, sex, BMI, HOMA-IR and physical activity (adjusted r2 = 0.271, p = 0.035). Conclusions: These results show biomarker evidence of neurodegeneration in adults at risk or with T2D. Larger sample size and longitudinal analysis are required to better understand the application of NfL in people with risk and overt T2D

    Docosahexaenoic acid-rich fish oil supplementation reduces kinase associated with insulin resistance in overweight and obese midlife adults

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    Targeting kinases linked to insulin resistance (IR) and inflammation may help in reducing the risk of type 2 diabetes (T2D) and Alzheimer’s disease (AD) in its early stages. This study aimed to determine whether DHA-rich fish oil supplementation reduces glycogen synthase kinase (GSK-3), which is linked to both IR and AD. Baseline and post-intervention plasma samples from 58 adults with abdominal obesity (Age: 51.7 ± 1.7 years, BMI: 31.9 ± 0.8 kg/m2) were analysed for outcome measures. Participants were allocated to 2 g DHA-rich fish oil capsules (860 mg DHA + 120 mg EPA) (n = 31) or placebo capsules (n = 27) per day for 12 weeks. Compared to placebo, DHA-rich fish oil significantly reduced GSK-3β by −2.3 ± 0.3 ng/mL. An inverse correlation (p \u3c 0.05) was found between baseline insulin and IR and their changes following intervention only in participants with C-reactive protein levels higher than 2.4 mg/L. DHA-rich fish oil reduces GSK-3 and IR, suggesting a potential role of long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) in ameliorating AD risk
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