Thermoelastic Stresses Alleviation for Two-Dimensional Functionally Graded Cylinders Under Asymmetric Loading

Open Access via the Taylor and Francis Agreement Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Peer reviewedPublisher PD

Different Approaches for Predicting Air Jet Spun Yarn Strength

V současné době tryskové dopřádání dosáhlo po půlstoletí svého vývoje průmyslového uznání a zaujalo své místo na trhu. Cílem této práce je přispět k poznání procesu tvorby příze, zmapovat vliv vybraných technologických parametrů tryskového dopřádacího stroje na vlastnosti příze, zejména její pevnost a především poskytnout širší náhled na problematiku predikce pevnosti tryskové příze. V práci je provedena trojrozměrná numerická simulace průtokového pole vzduchu uvnitř spřádací trysky tryskového dopřádacího stroje Rieter Air-jet. Byla analyzována distribuce rychlosti a tlaku vzduchu s cílem popsat princip tvorby příze. Analýza složek rychlosti a statického tlaku vzduchu ukázala, jak jsou uvnitř trysky tvořeny vzduchové víry, stejně jako způsob, jakým se příze formuje.Byla provedena numerická simulace spolu s experimentální verifikací, která zkoumala vliv tlaku kroutícího vzduchu na pevnost příze. Výsledky simulace přinesly dobrou shodu s experimentem. Výsledky ukázaly, že zvyšující se tlak v trysce vedl zpočátku ke zlepšení pevnosti příze, ale při vysokém tlaku vzduchu se pevnost zhoršila.Ve stěžejní části práci jsou prezentovány a popsány různé možnosti přístupů k predikce pevnosti příze. Jedním z nich je statistické modelování založené na experimentálních měřeních. V rámci tohoto přístupu byl sledován vliv délkové hmotnosti příze, odtahové rychlosti a nastaveného spřádního tlaku vzduchu. Pro analýzu kombinovaného vlivu těchto parametrů pomocí responzních povrchů byl použit vícenásobný regresní model. Na základě různých kombinací mezi sledovanými technologickými veličinami byly získány optimální parametry nastavení pro testovaný materiál.Jako druhý z možných přístupů k predikci pevnosti tryskové příze je navržen matematický model. Pomocí tohoto modelu lze predikovat pevnost 100% viskozové a 100% tencelové tryskové příze na krátkých upínacích délkách. Model je založen na výpočtu pevnosti jádra příze, jakožto paralelního svazku vláken, výpočtu pevnosti obalové vrstvy vláken jakožto svazku vláken ovinutého ve šroubovici kolem jádra příze. V modelu je rovněž zohledněn interakční účinek mezi vlákny v obalu a vlákny v jádru příze. Jako vstupní parametry modelu pro výpočet teoretické pevnosti příze na krátkých upínacích délkách jsou použity parametry vláken i strukturální parametry příze. Výsledky ukázaly, že přesnost navrhovaného modelu je uspokojivá pro soubor experimentálních přízí. Jako další z možných přístupů k predikci pevnosti příze (na krátkých úsečkách) je prezentován statistický model. Pomocí modelu je zkoumán vliv upínací délky příze v trhacím přístroji na pevnost a variační koeficient pevnosti tryskové, prstencové a rotorové příze. Model vychází z Peirceova modelu a předpokládá tříparametrové Weibullovo rozdělení hodnot pevnosti příze. Mezi experimentálními a predikovanými hodnotami byla zaznamenána přiměřená shoda. Model úspěšně zachytil změny pevnosti příze a její variační koeficient při různých upínacích délkách. Výsledky potvrdily, že při větších upínacích délkách pevnost příze klesá a její variační koeficient se rovněž snižuje.Air jet spinning process has reached an industrial acceptance stage having developed through half a century. This study aims to contribute to the knowledge of air-jet yarn formation process by investigating the influence of selected technological parameters of the Rieter air-jet spinning machine on yarn properties, especially its strength. Furthermore, to shed light on the problem of the prediction of yarn strength. A three-dimensional numerical simulation of the airflow field inside Rieter air jet spinning nozzle has been presented. The velocity and pressure distribution were analyzed to describe the principle of yarn formation. The analysis of velocity components and static pressure revealed how the air vortices are created inside the nozzle as well as how the yarn is spun.A numerical simulation along with experimental verification were performed to investigate the influence of nozzle pressure on air jet yarn tenacity and the results were in good agreement. The results show that increasing nozzle pressure resulted initially in improving yarn tenacity, but at high-pressure, tenacity deteriorates.Different approaches have been used to predict the tenacity of air jet yarn. One of these approaches is a statistical model, where the effect of yarn linear density, delivery speed and nozzle pressure on yarn strength were investigated and a multiple regression model was used to study the combined effect of these parameters and response surfaces were obtained. Based on the different combinations of processing variables, optimal running conditions for tested materials were obtained. As a second possible approach to predict yarn strength, a mathematical model that predicts the strength of Viscose and Tencel air jet spun yarn at short gauge length has been presented which is based on an earlier model. The model is based on calculating the core fiber strength as a parallel bundle of fibers. Also, calculating the wrapper fiber strength as a bundle of fibers in the form of helical path and considering the interaction effect between the wrapper and core fibers. Fiber parameters in addition to yarn structural parameters were used to obtain the theoretical yarn tenacity at short gauge length. Results showed that the accuracy of the proposed model is satisfactory for the tested yarns set.As an alternative approach to predict air jet yarn strength, a statistical model has been presented. By using this model, the influence of the tensile tester gauge length on the ring, rotor, and air jet spun yarn tenacity and its coefficient of variation has been investigated. The model correlates yarn tenacity and coefficient of variation of yarn tenacity to gauge length. The model is based on Peirce model and assuming the 3-parameter Weibull distribution of yarn strength values. A reasonable agreement has been shown between the experimental and the predicted values. The model successfully captured the change in yarn strength and its coefficient of variation at different gauge lengths. Results confirmed that at longer gauge lengths, yarn strength decreases and its coefficient of variation decreases as well

Well-being as a tool to improve productivity in existing office space: Case study in Alexandria, Egypt [version 2; peer review: 2 approved, 2 approved with reservations]

Background The green building industry has significantly impacted the construction market, providing various sustainable solutions for the community. However, conventional green building standards have yet to adequately address occupant health and well-being, leading to challenges with performance. This has caused many businesses to take note of the latest report from the Bureau of Labour Statistics, which indicated that productivity in the US has dropped by the sharpest level since the 1940s. 1 Addressing these issues, organisations like International WELL Building Institute (IWBI) developed WELL Building Rating System (WELL), prioritising occupant health and well-being as critical components for improving performance and avoiding potential vulnerabilities brought about by sickness or pandemics. For this reason, this study will explore how to improve employee productivity within office buildings by bettering their overall health and well-being. Methods A comprehensive data collection approach was employed in this paper, involving the analysis of office form evolution, and the evaluation of productivity attributes in office spaces. Resulting in identifying the top design-oriented features impacting employee productivity. Data was gathered from traditional office designs, trending successful office buildings, and the WELL Building Rating System to understand the concept of healthy building design. Results Showing thermal comfort, ventilation, and natural daylight significantly influence employees’ productivity. Implementing conducted design features from WELL achieved an average of 20.2%-35.6% decrease in thermal gain throughout the year, a 20% increase in airflow, an average 2.4%-6.5% decrease in Air temperature, enhanced temperature distribution by 7%, and direct sunlight minimum reduction by 9% in Winter and maximum 21.9% in Spring. Conclusion New design features in trending successful office buildings positively impact employee productivity. Particularly the outlined features by WELL Building Rating System led to identifying the most influential factors affecting occupant productivity. The results of this study informed recommendations for enhancing productivity in existing office buildings in Alexandria, Egypt

Role of serum allograft inflammatory factor-1 (AIF-1) in Egyptian type 2 diabetic patients

Background. Diabetes mellitus (DM) is a powerful and independent risk factor for cardiovascular disease. The atherosclerosis process in diabetes is indistinguishable from that of the nondiabetic population, but it begins earlier and is often more extensive and more severe. AIF-1 promotes chemotaxis, spreading and migration of macrophages and vascular smooth muscle cells (VSMCs) which suggest a role of AIF-1 in the atherosclerotic plaque formation. Thus, this study determines the role of AIF-1 in the Egyptian type 2 diabetic patients. Results. The level of AIF-1 was significantly higher in the type 2 diabetic group when compared to the control group (p = 0.000). In type 2 diabetic patients group, there was a significant positive correlation between CIMT and AIF-1 (r = 0.468, p = 0.000). In addition to the positive correlation between CIMT and AIF-1, CIMT in regression model analysis was significantly positive contributing to the outcome variable (AIF-1) (p < 0.05), denoting the possible role of elevated serum AIF-1 level in atherosclerotic process with further studies on larger scale needed

Evaluate the Socio-Economic Impact of the International Coastal Road (ICR) on Burg Elburullus City

Communities are grappling with environmental, social, and economic challenges due to rapid urbanization and physical changes, with coastal slums bearing the brunt of the impact. Unplanned urban development worsens pollution, inequality, and disaster risk for low-income households. Specific sustainable development plans are vital for tailored solutions based on each community's distinct needs and views. This study examines the socio-economic impacts of the establishment of the International Coastal Road (ICR) in the city of BURJ AL-BURULLUS in Northern Egypt, which marked the beginning of major urbanization efforts in the region in 2002. The physical landscape of the city has undergone significant changes due to urban expansion, with the extension of the city having grown to almost twice the size of the original city. The expansion of the city due to the ICR has caused significant changes to the area's environment, communities, and economies. In particular, the separation of the city from the nearby lake, which was its primary source of income, has had diverse impacts on various aspects of people's lives. This study employed a narrative method to assess ICR's impacts on the area's environments, communities, and economies. Nine villagers with diverse incomes were selected and encouraged to freely share their detailed views. The study focused on the socioeconomic impacts of the changes on the city, but it had significant impacts on all economic, social, and environmental levels. Community participation enhances research outcomes regarding the challenges experienced by impoverished communities due to urbanization. It also assists in the creation of improvement strategies responsive to the distinct requirements of each community by incorporating important perspectives and first-hand experiences of those affected by urbanization

Curcumin and cinnamon mitigates lead acetate-induced oxidative damage in the spleen of rats

Lead toxicity is a common occupational and environmental health hazard that exerts many toxic effects on animals and humans, including immunotoxicity. Curcumin (CUR) and cinnamon (CIN) are common medicinal herbs with immunostimulatory and antioxidant properties. Therefore, this study investigated the protective effect of curcumin and cinnamon against lead acetate (LA)-induced splenotoxicity in rats via hemato-biochemical, immunological, oxidative stress marker, CYP-2E1 expression, histological, and immunohistological evaluations. Four groups of seven rats each were used: the control group received corn oil as a vehicle; the lead acetate group received (100 mg/kg), the CUR + LA group received curcumin (400 mg/kg) plus lead acetate, and the CIN + LA group received cinnamon (200 mg/kg) plus lead acetate orally for 1 month. LA exposure induced macrocytic hypochromic anemia, leukocytosis, neutrophilia, monocytosis, and lymphopenia. Additionally, significant elevations in serum iron, ferritin levels, and transferrin saturation percentage with significant decline of total and unsaturated iron binding capacities (TIBC and UIBC), transferrin, and immunoglobulin G and M levels were recorded. In addition, lead acetate significantly upregulated splenic CYP-2E1 expression, that was evident by significant depletion of reduced glutathione (GSH) activity and elevation of malondihyde (MDA), nitric oxide (NO), and protein carbonyl (PC) concentrations in the spleen. Histologically, hyperplasia of lymphoid follicles, hemosiderin deposition, and disturbance of CD3 and CD68 immuno-expressions were evident in the spleen from the lead acetate group. However, curcumin and cinnamon administration restored the hemato-biochemical, immunological, and oxidative stress parameters as well as histological and immunohistological pictures toward normalcy. In conclusion, curcumin and cinnamon can partially ameliorate LA-induced oxidative damage in the spleen, possibly through their antioxidant, immunomodulatory, and gene-regulating activities

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication