Characterization of compressive damage behavior of steel and aluminum

Compressive deformation is imposed on aluminum cast 195-76 and ferritic stainless steel 18-8specimens at high strain rateusing perforation split Hopkinson pressure bar (P-SHPB).The energy levels and the compressive dynamic failure behavior of the materials were investigated at high strain rate deformation between 950 and 5700 s-1. This paper investigates the effects of specimen’s thickness andimpact energy on failure behavior with correlation of P-SHPB and SHPB.The relationship of different damage mode can be followed with the stress-strain relationship, strain rate and energy absorbed by steel and aluminum specimens

Compression of the material characteristics of steel, aluminum, wood and woven graphite epoxy composites in response to high strain rate load

The stresses developed in the material by impact load are analyzed experimentally, numerically, and analytically for specimens out of steel, aluminum, wood and woven graphite epoxy composites to investigate the material response to high strain rate stresses for aforementioned materials. The applied strain rates in experiments were set to be within 950 and 3500 s-1. The thin circular shape specimens were examined with high strain rate laboratory tests using the perforation split Hopkinson pressure bar (P-SHPB) with dimensional ratio accepted for One-dimensional stress analysis hypothesis. The article describes analytical solutions for one dimensional in detail to be implemented for numerical analyzing via trapezoid computation. The graphs of the four listed materials with two different thicknesses are compared for the specimen’s energy absorbed, specimen’s strain rate, stress strain rate relationship of the specimen, maximum energy absorbed, and maximum strain in specimen. It turned out that the dependency of deformation on energy absorption follows a power law for the woven composite and is approximated with linear relationships for aluminum and steel. Studying the effect of thickness in energy absorbed shows that doubling the thickness of the specimen reduces the strain of the specimen by 50 percentages for woven graphite epoxy and wood specimens, but the reduction is 25 percentages in the steel and aluminum specimen

Risk mitigation practices of the Lebanese banking sector: a proactive approach to maintain resilience through prudential regulations

The thesis reflects the student's field of interest and provides a unique exploration of the risk mitigation strategies of the Lebanese banking regulators. Its argument concerns the prudential regulation of financial stability and the key factors involved in maintaining the resilience of the banking system; hence the thesis explores the continuity of the system across the entire Lebanese banking sector and its application in the context of the Middle East. The thesis reviews and investigates the banking system in Lebanon and the issues derived from external factors imposed on the Lebanese economy. It discusses ways to mitigate risk and looks at the role of the banking authorities and supervision mechanisms that assure all policies and procedures are being implemented correctly by commercial banks. Moreover, the research highlights best practice as applied in the International Standard Banking Practice (ISBP) by the United States (US) and European Union (EU) and compares it to that applied in Lebanon. The aim of the thesis is to leverage the research outcomes to other countries in the Middle East and to make recommendations based on the lessons learned. Additionally, the thesis opens up new avenues for future researchers and practitioners. The core of the empirical research discussion of this thesis is built around the prudential regulations of the Lebanese banking system. Four sets of ratios and their scope of implementation in the field are investigated: Capital adequacy ratios, Liquidity ratios, Asset quality ratios and Profitability ratios. The research utilises transcripts from interviews with key stakeholders to ascertain their perception of the regulations' value and any problems they perceive with it. An interpretive approach has been employed to assess the likely response of the banking system to economic turmoil. The research has adopted a qualitative methodological approach to present an explanation for the choice of the methodology, which itself was influenced by the author's choice of Interpretivism, that is, the use of Interviews as the method for data collection. As a result, gaps were identified and analysed. The Research Questions, which have been framed and fine-tuned for this, the final document, Document 5 – The Thesis, are illustrated in a conceptual framework. The robustness of the conceptual framework is the result of the critical literature review, which provides an overview of the literature in relation to all the main concepts and ideas that this thesis explores. The empirical research concludes by identifying the main contributions the results can make to the business and academic fields. Briefly, the results concern the main characteristics of the Lebanese banking sector; the existence of a relationship between financial crisis and banking regulations; the policies and procedures used by Lebanese banks to set their financial ratios and the main indicators used to illustrate the resilience, stability and continuity of the banking sector; the central role played by the economic monitor Banque du Liban (BDL) in maintaining robust monetary policies; the weaknesses of the Lebanese banking sector and the necessity for Lebanese banks to adopt adequate corporate governance as well as the importance of political stability. Finally, the thesis closes by suggesting the importance of the research findings and their application in the context of the Middle East

Characterizing Unexpectedly Localized Slowing of the Thermospheric Cross‐Polar Jet of Neutral Wind Over Alaska in the Midnight Sector

NSF, GEO, Division of Atmospheric and Geospace Sciences (AGS). Grant Numbers: 1452333, 1341545Ye

Wavelike Oscillations in High Latitude Thermospheric Doppler Temperature and Line‐Of‐Sight Wind Observed Using All‐Sky Imaging Fabry‐Perot Spectrometers

NSF. Grant Numbers: 1341545, 1452333Ye

Pan-European early switch/early discharge opportunities exist for hospitalised patients with methicillin-resistant <em>Staphylococcus</em> <em>aureus</em> complicated skin and soft-tissue infections

AbstractThe objective of this study was to document pan-European real-world treatment patterns and healthcare resource use and estimate opportunities for early switch (ES) from intravenous (IV) to oral antibiotics and early discharge (ED) in hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infections (cSSTIs). This retrospective observational medical chart review study enrolled 342 physicians across 12 European countries who collected data from 1542 patients with documented MRSA cSSTI who were hospitalized (July 2010 to June 2011) and discharged alive (by July 2011). Data included clinical characteristics and outcomes, hospital length of stay (LOS), MRSA-targeted IV and oral antibiotic use, and ES and ED eligibility according to literature-based and expert-validated criteria. The most frequent initial MRSA-active antibiotics were vancomycin (50.2%), linezolid (15.1%), clindamycin (10.8%), and teicoplanin (10.4%). Patients discharged with MRSA-active antibiotics (n = 480) were most frequently prescribed linezolid (42.1%) and clindamycin (19.8%). IV treatment duration (9.3 ± 6.5 vs. 14.6 ± 9.9 days; p <0.001) and hospital LOS (19.1 ± 12.9 vs. 21.0 ± 18.2 days; p 0.162) tended to be shorter for patients switched from IV to oral treatment than for patients who received IV treatment only. Of the patients, 33.6% met ES criteria and could have discontinued IV treatment 6.0 ± 5.5 days earlier, and 37.9% met ED criteria and could have been discharged 6.2 ± 8.2 days earlier. More than one-third of European patients hospitalized for MRSA cSSTI could be eligible for ES and ED, resulting in substantial reductions in IV days and bed-days, with potential savings of €2000 per ED-eligible patient

Wireless earbuds for low-cost hearing screening

We present the first wireless earbud hardware that can perform hearing screening by detecting otoacoustic emissions. The conventional wisdom has been that detecting otoacoustic emissions, which are the faint sounds generated by the cochlea, requires sensitive and expensive acoustic hardware. Thus, medical devices for hearing screening cost thousands of dollars and are inaccessible in low and middle income countries. We show that by designing wireless earbuds using low-cost acoustic hardware and combining them with wireless sensing algorithms, we can reliably identify otoacoustic emissions and perform hearing screening. Our algorithms combine frequency modulated chirps with wideband pulses emitted from a low-cost speaker to reliably separate otoacoustic emissions from in-ear reflections and echoes. We conducted a clinical study with 50 ears across two healthcare sites. Our study shows that the low-cost earbuds detect hearing loss with 100% sensitivity and 89.7% specificity, which is comparable to the performance of a $8000 medical device. By developing low-cost and open-source wearable technology, our work may help address global health inequities in hearing screening by democratizing these medical devices

Quantum computing for fluids: where do we stand?

We present a pedagogical introduction to the current state of quantum computing algorithms for the simulation of classical fluids. Different strategies, along with their potential merits and liabilities, are discussed and commented on

Varenicline Versus Nicotine Replacement Therapy for Long-Term Smoking Cessation:An Observational Study Using the Clinical Practice Research Datalink

Background Smoking is the leading avoidable cause of illness and premature mortality. The first-line treatments for smoking cessation are nicotine replacement therapy and varenicline. Meta-analyses of experimental studies have shown that participants allocated to the varenicline group were 1.57 times (95% confidence interval 1.29 to 1.91 times) as likely to be abstinent 6 months after treatment as those allocated to the nicotine replacement therapy group. However, there is limited evidence about the effectiveness of varenicline when prescribed in primary care. We investigated the effectiveness and rate of adverse events of these medicines in the general population. Objective To estimate the effect of prescribing varenicline on smoking cessation rates and health outcomes. Data sources Clinical Practice Research Datalink. Methods We conducted an observational cohort study using electronic medical records from the Clinical Practice Research Datalink. We extracted data on all patients who were prescribed varenicline or nicotine replacement therapy after 1 September 2006 who were aged ≥ 18 years. We investigated the effects of varenicline on smoking cessation, all-cause mortality and cause-specific mortality and hospitalisation for: (1) chronic lung disease, (2) lung cancer, (3) coronary heart disease, (4) pneumonia, (5) cerebrovascular disease, (6) diabetes, and (7) external causes; primary care diagnosis of myocardial infarction, chronic obstructive pulmonary disease, depression, or prescription for anxiety; weight in kg; general practitioner and hospital attendance. Our primary outcome was smoking cessation 2 years after the first prescription. We investigated the baseline differences between patients prescribed varenicline and patients prescribed nicotine replacement therapy. We report results using multivariable-adjusted, propensity score and instrumental variable regression. Finally, we developed methods to assess the relative bias of the different statistical methods we used. Results People prescribed varenicline were healthier at baseline than those prescribed nicotine replacement therapy in almost all characteristics, which highlighted the potential for residual confounding. Our instrumental variable analysis results found little evidence that patients prescribed varenicline had lower mortality 2 years after their first prescription (risk difference 0.67, 95% confidence interval –0.11 to 1.46) than those prescribed nicotine replacement therapy. They had similar rates of all-cause hospitalisation, incident primary care diagnoses of myocardial infarction and chronic obstructive pulmonary disease. People prescribed varenicline subsequently attended primary care less frequently. Patients prescribed varenicline were more likely (odds ratio 1.46, 95% confidence interval 1.42 to 1.50) to be abstinent 6 months after treatment than those prescribed nicotine replacement therapy when estimated using multivariable-adjusted for baseline covariates. Patients from more deprived areas were less likely to be prescribed varenicline. However, varenicline had similar effectiveness for these groups. Conclusion Patients prescribed varenicline in primary care were more likely to quit smoking than those prescribed nicotine replacement therapy, but there was little evidence that they had lower rates of mortality or morbidity in the 4 years following the first prescription. There was little evidence of heterogeneity in effectiveness across the population