Greater Strain Research Articles

A Laboratory Methodological Proposal for “Geotechnical Lime Stabilization of A-4 Soils”

This paper establish the beginning of a research process regarding the behavior of soils stabilized with lime. Generally, the geotechnical practice of soils stabilized with lime requires a first step conducted in the laboratory, to attest the features of “natural soils” in order to improve their behavior in term of geotechnical performance and, a second step, carried out onsite with experimental test fields, in order to verify the benefit obtained by the use of lime treatments. The topic of this research focuses on the first step above described. In order to provide geotechnical laboratory tests useful to our purpose, A-4 soils (according to HRB classification) and CL-ML (according to USCS soils classification) were tested. These soils show a large distribution in the Piedmont Po Plain (NW Italy): they outcrop in correspondence to terraced alluvial fans linked to alpine watercourses and are generally applied for stabilization with lime for foundation structures and pavements. Additionally, these soils are mainly inorganic with a marked tendency towards sandy silt soils with the presence of gravel. The presence of gravel results on a greater strain hardening in the behavior of shear strength of soils. Finally, in support of geotechnicians, who have to draw up specifications, a systematized laboratory methodology to follow for A-4 soils stabilization with lime is here reported and a detailed analyses of mechanical behavior obtained on “soil-lime-water mixtures” is described.

Fragmentation of photovoltaic backsheets after accelerated weathering exposure

The backsheet of a photovoltaic (PV) module functions primarily to provide safe operation through electrical insulation and protect the interior from environmental exposure. For most applications, backsheets consist of opaque, but highly reflective, films that protect inner layers from degradation from ultraviolet (UV) light. Backsheets can fail if they delaminate or form cracks under strain. In a PV module, the maximum strains that can be applied are only on the order of a few percent. The greatest strains are likely to be highly localized around topographical features. Therefore, to assess the likelihood of a crack being initiated in a backsheet, we apply small amplitude strains to backsheet films under microscopic examination using a laser scanning confocal microscope. This allows us to monitor both the depth and density of cracks as well as the onset strain. Here we perform these measurements after exposure to UV light.

High initial IgG antibody levels against Orientia tsutsugamushi are associated with an increased risk of severe scrub typhus infection.

BackgroundScrub typhus is a dominant cause of febrile illness in many parts of Asia. Immunity is limited by the great strain diversity of Orientia tsutsugamushi. It is unclear whether previous infection protects from severe infection or enhances the risk.Methods/principal findingsWe studied IgG antibody levels against O. tsutsugamushi at presentation in 636 scrub typhus patients using enzyme-linked immunosorbent assays (ELISA). The association between ELISA optical density (OD) and risk of severe infection was modelled using Poisson regression. OD was categorised as low (<1.0), intermediate (1.0 to 2.9), and high (≥3.0). OD was also modelled as a continuous variable (cubic spline). Median age of cases was 41 years (range 0–85), with 37% having severe infection. Compared to the low category, the age-adjusted risk of severe infection was 1.5 times higher in the intermediate category (95%CI 1.2, 1.9), and 1.3 times higher in the high category (95%CI 1.0, 1.7). The effect was stronger in cases <40 years, doubling the risk in the intermediate and high categories compared to the low category. The effect was more pronounced in cases tested within 7 days of fever onset when IgG ODs are more likely to reflect pre-infection levels.Conclusions/SignificanceIntermediate and high IgG antibody levels at the time of diagnosis are associated with a higher risk of severe scrub typhus infection. The findings may be explained by severe infection eliciting an accelerated IgG response or by previous scrub typhus infection enhancing the severity of subsequent episodes.

Chaotic Neural Network-Based Hysteresis Modeling With Dynamic Operator for Magnetic Shape Memory Alloy Actuator

The magnetic shape memory alloy (MSMA) is a new family of smart materials, which exhibits great strain deformation and high energy density. Based on these properties, the MSMA has excellent potential to represent an available means for developing a novel generation of actuators in the micro-positioning application. However, the MSMA-based actuator suffers from the inherent hysteresis and it has become a bottleneck in the industrial application. A hybrid hysteresis model, which consists of a simple dynamic hysteresis operator (SDHO) and chaotic neural network (CNN), is proposed in this article. This developed model possesses a concise construction and distinguished generalization capability. By conducting comparative experiments, the proposed approach has a superior ability to predict the hysteresis behaviors under various input signals.

Financial analysis of revision knee surgery at a tertiary referral centre as classified according to the Revision Knee Complexity Classification (RKCC)

BackgroundRevision total knee arthroplasty (rTKA) can be complex, with greater costs to the treating hospital than primary TKA. A rTKA regional network has been proposed in England. The aim of this work was to accurately quantify current costs and reimbursement for the rTKA service and to assess whether costs are proportional to case complexity at a tertiary referral centre within the National Health Service (NHS). MethodsA review of all rTKA performed at our institution over two consecutive financial years (2017–2019) was performed. Cases were classified according to the Revision Knee Complexity Classification (RKCC) and by mode of failure; “infected” and “non-infected”. Financial data was acquired through Patient-Level Information and Costing System (PLICS). The primary outcome was the financial difference between tariff and cost per episode. Comparisons between groups were analysed using analysis of variance and two-tailed unpaired t-test as appropriate. Results159 patients underwent 188 rTKA procedures. Length of stay and cost significantly increased between complexity groups (p < 0.0001) and for infected revisions (p < 0.0001). All groups sustained a mean deficit but this significantly increased with revision complexity (from £1,903 to £5,269 per case) and for infected revisions. The total deficit to the Trust for the two-year rTKA service was £667,091. ConclusionsThe current level of NHS reimbursement are inadequate for centres that offer rTKA and should be more closely aligned to case complexity. An increase in the most complex rTKA at major revision centres will undoubtedly place an even greater strain on the finances of these units.

Black women and COVID-19: The need for targeted mental health research and practice.

COVID-19 has significantly impacted a substantial number of Black Americans. Black women, in particular, are facing challenges financially, physically, and mentally during this unprecedented time. Between serving as frontline workers, being concerned about contracting the virus, contributing to their families financially, and worrying about their loved ones’ health, Black women are experiencing great strain on their mental health and well-being. These stressors illustrate the need for social work researchers and practitioners to address Black women’s mental health. This paper presents our reflections, experiences, and response to COVID-19 as Black women and scholars. Guided by our reflections and personal experiences, we put forth suggestions and reflexive thoughts for social work researchers and practitioners to prioritize Black women’s mental health during and after these unprecedented times.

Wave Theory of Seismic Resistance of Underground Pipelines

The object of the research is an underground straight horizontal pipeline subjected to seismic impact. The research method was analytical. The results were compared with the experimental results of other authors and computer calculations. It was shown that the main disadvantage of the dynamic theory of seismic resistance of underground pipelines is the neglect of the dynamic stress state in soil under seismic wave propagation. The next drawback of the dynamic theory is an inaccurate, approximate accounting for the displacement of the soil medium to which the underground pipeline is embedded. The complete interaction process includes the stages of nonlinear changes in the interaction force (the friction force) by manifesting its peak value and the Coulomb friction. The contact layer of soil undergoes shear deformations until complete structural destruction of the soil contact layer. The interaction force is the friction force, and its peak value does not appear. The seismic resistance of underground pipelines should be considered based on the theory of propagating seismic waves in a soil medium and the interaction of seismic waves with underground pipelines, i.e., based on the wave theory of seismic resistance of underground pipelines. A one-dimensional coupled problem of seismic resistance of underground pipelines under seismic impacts was posed based on the wave theory. An algorithm and a program for the numerical solution of the stated wave problems were developed using the method of characteristics and the method of finite differences. An analysis of the laws of interaction of underground pipelines with soil under seismic influences shows that it is necessary to use in the calculations the laws of interaction that account for the complete interaction processes observed in experiments. The analysis of the obtained numerical solutions and the posed coupled problems of the wave theory of seismic resistance of underground pipelines show the occurrence mechanisms of longitudinal stresses in underground pipelines under seismic influences. The results of calculations stated that an account for the dynamic stress normal to the underground pipeline’s outer surface leads to multiple increases in longitudinal stress in the underground pipeline. This multiple increase is due to the transformation of the interaction force into an active frictional force, resulting from a greater strain in soil than the one in the underground pipeline. Based on the analysis results, a theory of the seismic wave propagation process in an underground pipeline and surrounding soil was proposed.

O fenômeno do estresse em professores do Ensino Fundamental: uma revisão integrativa

Objetivo: identificar os fatores de risco e proteção, e estratégias de enfrentamento do estresse em professores do ensino fundamental em escolas públicas. Metodologia: trata-se de estudo de abordagem qualitativa, exploratória bibliográfica, com síntese de produções cientificas através de revisão integrativa. A busca de artigos foi realizada entre os meses de maio a agosto de 2020, utilizando-se os Descritores de Saúde: Estresse Psicológico; Professores Escolares, e o operador boleano “AND”. Resultados: foram analisados 10 artigos, publicados no ano de 2020. Percebe-se que os professores passam por diversos estressores, que estão diariamente os acompanhando e que perpassam as mais diversas ordens como: salas super lotadas, indisciplina dos alunos, falta de estrutura física e material, falta de atenção e compromisso dos alunos com a escola, fazendo com que se sintam desvalorizados, desrespeitados e muitas vezes culpabilizados, por não darem conta de abarcar todas as funções que lhe são impostas. Essas condições de trabalho, nas quais os professores usam de todas as suas capacidades físicas, cognitivas e afetivas para atingir os objetivos da produção escolar podem acabar gerando um grande esforço de suas funções psicofisiológicas. Considerações finais: O estresse em professores do ensino fundamental é real, e pode levar a sério problemas de saúde mental e física desses profissionais.

Strengthening mechanism and plasticity deformation of crystalline/amorphous Cu/CuTa nanomultilayer

Through the tensioning process using molecular dynamics simulation method, the mechanistic properties of the Cu/CuTa crystalline/amorphous nanomultilayers (CANMs) are explored. In the Cu layers, the phase transition from FCC to HCP occurs. The embryonic shear bands (ESBs) essentially appear from the crossing positions of the stacking faults and interfaces, after that, grow to establish the shear transformation zones (STZs). The great shear strain atoms concentrate into the diagonal strips that create with the horizontal direction an angle of 45°. The Cu/CuTa CANMs with more layers are more easily damaged. For the cases with the different w2 values, the f0.3 value reduces with the increase of the w2 value. The tensile strength increases with the w2 increases and the inverse Hall-Petch relation is observed. For the Cu/Cu10Ta90, Cu/Cu25Ta75, and Cu/Cu90Ta10 CANMs, the shrinkages are explicit, the formation of the STZs is more obvious than that in the Cu/Cu50Ta50, Cu/Cu75Ta25 specimen.

Decision support system for selection of appropriate water supply and sanitation technologies in developing countries

Abstract Access to water supply and sanitation services remains a challenge in many parts of the world. The expected growth of the world's population, from about 7.8 billion people today to 9.8 billion people by 2050, and to around 11 billion people by the end of 2100, will create even higher demand and a greater strain on these basic services. Goal 6 of the United Nations Sustainable Development Goal (SDG) aims to ‘Ensure availability and sustainable management of water and sanitation for all’ by 2030. However, in a recent report, UN-Water warns us that if things continue on the current path, the world will miss the targets of SDG 6. The selection of appropriate water and sanitation technologies is key to meeting SDG 6 targets. This paper presents an original framework of a decision support system (DSS) for the selection of appropriate water supply and sanitation (Watsan) technologies in developing countries. The proposed DSS has three components. The first component is the user interface, where the inputs are the assessment of a community's capacity to manage a given water supply or sanitation system, and its regional specificity. The second component of the DSS is a database of Watsan technologies classified according to the capacity requirement level (CRL) metric, and finally, the third component is a matching algorithm for the selection of appropriate Watsan technology options. Case studies and simulations results are presented for the evaluation of the performance of the decision support system.

Need for Nurse Practitioner Fellowships in Ophthalmology in the USA.

Medical attention to vision impairment and associated eye care complications are a vital component of daily living and overall well-being. In the United States today, the physician to patient deficit places great strain on the availability of medical attention tenable to patients nationwide; in terms of specialty medicine, this deficit is even more widespread. The field of ophthalmology faced the same physician to patient deficit in 2020, a grim reality that has left many states void of ophthalmic care, rending millions of aging individuals without domestic eye care. The implementation of trained, ophthalmic nurse practitioners (NPs) can fill the needs of this deficit; however, efficient, accredited, and board-approved American ophthalmic fellowships and residencies that secure proper ophthalmic NP transitions from academia to clinical practice are non-existent. Though scant, evidence-based literature presents sound findings that support the efficacy and benefit for superior patient outcomes with care provided by ophthalmic-trained NPs, offering a viable, long-term solution to the need for ophthalmic medical providers across all states without mitigating patient care, emphasizing the great need for the implementation of ophthalmic NP residencies and fellowships to ensure the continuity of impeccable ophthalmic care for all populations.

Stress distribution analysis in anterior teeth caused by several retraction mechanics.

ABSTRACTIntroduction: Orthodontic retraction of the anterior teeth is indicated when the patient has a malocclusion with protrusion of the incisors. Several mechanics are indicated to perform this retraction. Objective: The objective of this study was to compare the strains generated by four different types of retraction mechanics along the roots of the anterior teeth.Methods: A photoelastic model simulating an arch with first premolars extraction was made. Sixty retraction archwires were prepared, including fifteen for each type of mechanics evaluated: sliding, teardrop loop spring, T-loop spring and double key loop archwire. The strains were observed in two perspectives: occlusal and oblique. In the occlusal perspective, strains were compared among the six anterior teeth. From the oblique perspective, strains were compared among the thirds of the left canine root.Results: In the occlusal perspective, the teardrop loop spring mechanics presented greater strains, followed by T-loop spring, double key loop archwire and sliding mechanics. In all mechanics, strains were more concentrated in the canines than in the incisors. From the oblique perspective, the teardrop loop mechanics generated greater strains in the cervical regions of the canine, and in the apical regions, no differences were found in strains among the four types of mechanics. In the same mechanics, greater strains were present in the cervical zones. Conclusion: The teardrop loop spring retraction mechanic presented the greatest mean strain, and the sliding retraction mechanic presented the lowest mean strain on the root of anteroinferior teeth in the occlusal and oblique perspectives.

Wear a Mask, Practice Social Distancing after Being Vaccinated for COVID-19

There is a risk of over-dependence on innate immunity. As scientists arrange to perceive India’s slippery Covid case count, consultants have additionally cautioned of virus spikes ahead given the presence of mutant and more transmissible strain. until currently eighty two persons are detected with new Great Britain strain in Bharat. The covid vaccination in conjunction with public health measures would definitely be a safer possibility than betting on assumed herd immunity from natural infections. According to faculty member Reddy, as way as herd immunity is bothered, we have a tendency to still don't understand what fraction of our population has been infected in numerous elements of the country, it's impossible that the complete country has reached the herd immunity threshold. Unless every individual is immune, we have a tendency to not say that herd immunity has fully taken care of the matter, as a non-immune person remains inclined once he or she visits Associate in nursing other cluster that has an actively current virus.

The Psychological Impact of Coronavirus Disease 2019 on Nurses in Saudi Arabia and Their Coping Strategies.

Aims and ObjectivesTo explore the psychological impact of coronavirus disease 2019 on frontline nurses working in Jazan, Saudi Arabia, and their coping strategies.BackgroundAs the coronavirus disease 2019 pandemic continues to expand globally, healthcare systems have become more overwhelmed than ever before, placing a great psychological strain on frontline nurses.DesignA cross-sectional, observational, quantitative study.MethodsIn total, 215 frontline nurses working at 12 hospitals across Jazan, Saudi Arabia, were recruited. Data were collected during August 2020 using a modified version of the severe acute respiratory syndrome team questionnaire.ResultsRoughly two-thirds (62.3%) of the participants reported moderate to high levels of nervousness and fear at work. Ethical and moral responsibility has been determined as the main motivator for frontline nurses to practice their profession, with 88% of them expressing a willingness to work even if the situation deteriorated further. However, 87% of the participants were extremely concerned about transmitting the disease to their family members. The most common coping strategy adopted by the nurses appeared to be adherence to strict protective measures (93.5%), followed by the acquisition of more knowledge about the disease (82.3%).ConclusionFrontline nurses experience severe psychological stress, which is mainly caused by their fear of contracting the infection or passing it on to their family members. Thus, proper education, adherence to infection control protocols, effective social support system, and access to sufficient personal protective equipment will help nurses enhance their coping abilities.

Measuring the COVID-19 Financial Threat to Hospital Markets.

Many hospitals have been straining under the financial stress of treating COVID-19 patients. Those experiencing the greatest strain are in markets burdened with high levels of debt and uncompensated care. We propose a new measure of financial risk in a hospital market, combining both pre-existing financial vulnerability and COVID-19 severity. It reveals the highest concentrations of risk in counties with high poverty, low population density, and high shares of foreign-born and non-White populations. The CARES Act Provider Relief Fund helped many of the hospitals in these regions, but it left many markets with the same overall vulnerability to financial strain from the next health crisis.

Projected shortfall in personal income tax revenues of regional governments in Russia due to the COVID-19 pandemic

The COVID-19 pandemic has put a great strain on the Russian economy and budget revenue. The study aims at furnishing an estimate of losses in personal income tax revenue in regional government budgets in 2020–2023 due to the COVID-19 pandemic. In order to investigate the shortfall in tax revenues, three factors were studied: the amount of damage caused by the COVID-19 outbreak to the whole economic system; the sensitivity of the state revenue base to the crisis; the sensitivity of regional tax revenue to the revenue base. The study was based on the annual reports of the Federal Tax Service of Russia, Rosstat data, Forecast of the Social and Economic Development of the Russian Federation, and data from the “National action plan to ensure the recovery of employment and incomes of population, economic growth and long-term structural changes in the economy”. It was found that recession will lead to a significant reduction in people’s income over the given period. As a result, personal income tax revenues will decrease. The budget losses will reach 416.6 billion rubles by the end of the 2020 fiscal year. This is equivalent to 0.4% of GDP and 9.7% of total income from personal income tax in an economic situation unmarred by the pandemic. The largest fall in public revenue is expected in the regions which stand out in regard to personal income tax revenues per capita. The research results confirm the initial hypothesis that the negative impact of the pandemic on personal income tax revenues depends on the share of income tax revenues of a particular region or municipality. The findings can be used by the regional and municipal financial authorities for developing draft budgets for 2022 and the planning period of 2023–2024.

Ultra-stretchable, self-adhesive, transparent, and ionic conductive organohydrogel for flexible sensor

Conductive hydrogels are an ideal bio-integrated soft material and show great potential in soft sensors. However, it remains a great challenge to develop an integrated conductive gel combining excellent environmental stability and mechanical properties. Herein, we synthesize a transparent, self-adhesive conductive organohydrogel with excellent environmental stability and UV-blocking performance by constructing multiple cross-links between tannic acid, polyacrylamide, and polyvinyl alcohol. The addition of vinyl hybrid silica nanoparticles can promote dynamic cross-linking of polymer networks and endow organohydrogels with superior mechanical performance (&amp;gt;1800%, 320 kPa). Concurrently, the binary solvent system comprising water and ethylene glycol enables organohydrogels to accommodate different application environments (from −40 °C to 40 °C). Notably, with the incorporation of tannic acid, organohydrogels exhibit lasting and repeatable adhesion (80 kPa), as well as good UV-blocking (&amp;gt;90%). Furthermore, these conductive organohydrogels with great strain sensitivity were used as strain sensors to monitor and distinguish large movements (soft robot movements) and subtle human movements (smiling and electrocardiograph signal) at different temperatures. The conductive organohydrogels have great potential in healthcare monitoring and smart wearable soft electronic devices.

Enhanced dynamic mechanical properties and resistance to the formation of adiabatic shear band by Cu-rich nano-precipitates in high-strength steels

Cu-rich nano-precipitate strengthened steel is a kind of promising impact-resistant structural materials due to its perfect combination of strength and ductility. In this study, the effects of the Cu-rich nano-precipitates on the dynamic mechanical properties, deformation resistance and adiabatic shear band formation were systematically investigated. It is found that the Cu-rich nano-precipitates can effectively improve the strength at high strain rate during dynamic deformation. The maximum flow stress reaches ~2565 MPa at the strain rate of 6000 s−1, presenting the outstanding dynamic mechanical properties. The nano-precipitate-strengthened steel has a great positive strain rate sensitivity at a high strain rate, showing the excellent resistance to high-speed deformation and delayed fracture. The nano-precipitates can effectively hinder the formation and development of the adiabatic shear bands and improve significantly the maximum flow stress and microstructure stability during the high-speed impact.

Health-Related Quality of Life Factors in African American Caregivers of Persons With Dementia

African American caregivers of persons living with dementia have a high prevalence of caregiving compared to other caregiving groups. The goal of this study was to explore health-related quality of life factors in a sample (n=25) of African American caregivers with a body mass index of more than Caregivers were female (87%). Caregivers were an average age of 63.2 (±6) years, had 16.6 (±2) years of education, and were providing care for 4.3 (±4) years. Care-recipients were on average 79.1 (±11) years and mothers (52.2%). 74% of the caregivers reported good-to-excellent quality of life. Caregivers reported low anxiety and depression but high perceived stress and strain. Higher anxiety and depression were correlated with greater strain and lower quality of life. Healthcare providers need to examine specific situational caregiving factors that can affect African American caregiver outcomes; since, their stress and strain may not reflect in their response to psychological questionnaires.

Vision Impairment Among Late Mid-Life Women: Michigan Study of Women’s Health Across the Nation

There are few data on mid-life sensory health and its contribution to health and disability outcomes. The Study of Women’s Health Across the Nation—Michigan site (N=252 women, mean age=66.0 years) collected comprehensive data regarding ocular health to estimate the burden and correlates of vision impairment (VI) and unmet need for vision correction in this population. The prevalence of VI based on presenting and best-corrected visual acuity was 11.1% (95% CI 7.5,15.7) and 2.8% (95% CI 1.1,5.6), respectively. Thus, 75.0% of presenting VI was correctable, yet only 29.0% of women wore an appropriate eyeglass prescription. Black women and those with greater financial strain or less education were more likely to have presenting VI, but there were no differences in best-corrected VI. This presentation will include a discussion of the contributions of SWAN to the study of sensory aging, as well as methodological considerations for research from a mid-life aging cohort. Part of a symposium sponsored by Sensory Health Interest Group.