Experimental and numerical investigation of an innovative method for strengthening cold-formed steel profiles in bending throughout finite element modeling and application of neural network based on feature selection method

This study evaluates an innovative reinforcement method for cold-formed steel (CFS) upright sections through finite element assessment as well as prediction of the normalized ultimate load and deflection of the profiles by artificial intelligence (AI) and machine learning (ML) tech-niques. Following the previous experimental studies, several CFS upright profiles with different lengths, thicknesses and reinforcement spacings are modeled and analyzed under flexural loading. The finite element method (FEM) is employed to evaluate the proposed reinforcement method in different upright sections and to provide a valid database for the analytical study. To detect the most influential factor on flexural strength, the “feature selection” method is performed on the FEM results. Then, by using the feature selection method, a hybrid neural network (a combination of multi-layer perceptron algorithm and particle swarm optimization method) is developed for the prediction of normalized ultimate load. The correlation coefficient (R), root mean square error (RMSE), Nash–Sutcliffe efficiency (NSE), mean absolute error (MAE) and Wilmot’s index of agree-ment (WI) are used as the measure of precision. The results show that the geometrical parameters have almost the same contribution in the flexural capacity and deflection of the specimens. According to the performance evaluation indexes, the best model is detected and optimized by tuning other algorithm parameters. The results indicate that the hybrid neural network can successfully predict the normalized ultimate load and deflection

Effects of Transcranial direct current stimulation on Imagery ability in students

The purpose of this study was to investigate the effects of Transcranial direct current stimulation on Imagery ability in students. By semi-experimental method sixty students was selected from physical education students of University of Tehran and by at available sampling method and assigned into four groups: sham (control) and anodal (tests) (each of 15) for P4 and F4 point. Then, Participants were asked to perform MIQ-3 before and after transcranial direct current stimulus. Data analyze showed that there is a significant difference between the pre-test and post-test of all variables and it was revealed that there is a significant difference between the two groups of anodal and sham in both P4 and F4 points in motor Imagery and internal Imagery. In examining the difference between the two points, P4 and F4, there was no significant difference between the two points for the effectiveness of the illustrative capability. Based on the findings of the present study, it is suggested that tDCS at one of the P4 or F4 points should be used as a strategy to improve and enhance the ability of internal mental imagery in athletes as well as patients for rehab

Highly Conserve Sequences in Envelope, Nucleoprotein and RNA-Dependent RNA Polymerase of SARS-CoV-2 in Nasopharyngeal Samples of the COVID-19 Patients; a Diagnostic Target for Further Studies

Background: The etiological agent of COVID-19 is SARS-CoV-2. Conversional molecular methods used for detection of virus in COVID-19 infected patient. This study aimed to investigate the presence of escape mutations from molecular detection on SARS-CoV-2 targeted genes, which indicates importance of mutations in false negative PCR test results in detection of virus in clinical specimens of patients with COVID-19. Material and Method: The 20 nasopharyngeal swabs samples collected from COVID-19 confirmed patients. The SARS-CoV-2 E, nsp12 and N genetic regions Amplified by RT-PCR assay. PCR products sequenced using the Sanger sequencing method and Multiple sequence alignment for the assessment of the polymorphism and mutations preformed using MEGA X software and Maximum likelihood method for the phylogenetic assessment. Result: Among all COVID-19 cases 60% and 40% were male and female, respectively. The MSA showed high conservation between all of the evaluated samples and VOCs in all N, E and nsp12 genes. Also, the phylogenetic evaluation by Maximum likelihood method reported high similarity between all SARS-CoV-2 sequenced samples, VOCs and Wuhan reference sequence in evaluated region. Conclusion: Our study results approved the relatively conserved suitability of the E, N and RdRp-gene regions without any diversity, therefore, making them perfect candidates for first-line screening

A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs). Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings. Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran. Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p<0.001). Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions

Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic

O OR RI IG GI IN NA AL L A AR RT TI IC CL LE E Comparison of Dual System of Steel Moment frame and Thin steel Plate shear walls with Dual system of Steel moment frame and cross Bracing or Chevron with a Design Method based on Performance levels

ABSTRACT Various systems are applied to counteract lateral forces and especially the earthquake force, including: dual systems that include combined system of moment frame and other resistant systems. In 2800 code system, dual systems of steel moment frame include moment frame and the variety of braces and steel shear wall 4 is not mentioned. Only in the code system of the law of Canada (CAS, 1994) INTRODUCTION Iran is among the countries that have seen so many lives and the financial losses in the earthquake, therefore noticing seismic resistant systems seem essential. In the steel buildings, moment frame system seems an appropriate system due to good ductility and possibility of high dissipation of earthquake energy. The main problem of this system is in lateral displacement and in other words in lack of sufficient hardness. To solve this problem, idea of using dual systems including steel moment frame and another resistant system that actually is the complementary of this resolute system of the problem of replacement of moment frame came to mind. Complementary system of moment frame in dual systems in Iran is converging and non-converging braces. Converged braces generally include cross and chevron (vestibule) braces. In recent years, in many countries another new system called thin steel moment frame shear walls is also used as complementary of moment frame in dual systems. This new system is been well-received due to the speed of implementation and economic cost, but in our country it's been rarely used because of lack of knowledge and lack of adequate regulations of the country rather than other countries. In this paper, we try to compare a design method based on performance levels, which is a new and efficient way about the non-linear behavior of structures, between complementary systems for intermediate moment frames, i.e. the thin steel shear walls and converging braces. For comparison, 5 frames of different spans and heights have been considered and the performance point of these frames is calculated using capacity spectrums, also the rate of energy dissipation and coefficient of behavior of intermediate steel moment frame dual system and thin steel plate shear wall is calculated. Design method based on performance levels Design method based on resistance doesn't make an appropriate response in many cases because of the structural elements of the resistivity parameter. In this method possibility of accurate assessment of structures based on their expected performance doesn't occur. For this reason, in recent year

Durability Evaluation of Concrete Made of Fly Ash and Copper Slag

In this paper, to improve the durability of concrete, fly ash has been used as a percentage of cement and copper slag rather than a percentage of sand. Using a resistance test and water permeability test, four series of concrete specimens containing fly ash and copper slag, each containing 49 concrete mixing designs, were evaluated. After obtaining the results, eight samples with the highest electrical resistance were selected and the specimens were again tested in different environmental conditions. The results show that the environmental conditions of sulfate and carbonate have the least and most impact on reducing durability and there is a power relationship, with good precision, between the water penetration of the test specimens and the electrical resistance of the test specimens

The Effects of Grout Curtain Parameters on Uplift and Piping Phenomenon; Case Study: Sattarkhan Dam

Design of earth dams and their issues during and after construction is very important for residents downstream of the dam because of the potential risks and possible breakdowns. In the design of dams, various forces influence the dam body, including uplift pressure and piping phenomenon which should be considered in order to ensure the safety of the dam. Among the measures taken to prevent the washing away phenomenon, the reduction of the output gradient, and the leakage discharge from beneath the hydraulic structures, construction of the grout curtain and installation of the drainage are applicable. Therefore, in order to investigate the effect of various parameters such as the gradient angle of the grout curtain, length, and distance and the number of grout curtains, as well as the length of the drainage on the pressure and output gradient of the numerical models, were considered in current study. For this purpose, the SEEP/W software was used for modeling on Sattarkhan Dam as a case study. The results of the analysis showed that the use of the Qa’im grout curtain at the upstream of the dam has the highest resistance against the pressure and piping phenomenon. The results also showed that increase in the length of the curtain of the water seal increases safety against uplift and piping phenomenon. The use of further spacing between the two grout curtains under the core of the dam led to increase in overall pressure or reduction in safety against uplift pressure. Increase in the length of the horizontal drainage reduced the effects of uplift pressure and output gradient. Results show that period of 70 to 110 degree is appropriate for curtain angle and setting curtain in upstream of dam core with angle of 70 to 80 degree is optimum and economic. A length of 30 m is optimum for curtain. The number of 2 curtains is also optimum. Studying various scenarios of distance of 2 curtains in dam core indicates that distance of 6 m is optimum and also length of 18 m for horizontal drainage is optimum

Elimination trial with six tree species in Korbal plain and ‎effects of drainage water on their growth

The aim of the study was to investigate the adaptability of six native and exotic tree species at Korbal plain, Shiraz, I. R. Iran and the effects of drainage water on their growth and survival. The experiment design was split plots with three replicates. The main plots consisted of salty and ordinary water, supplied by drainage channels and Kor river, respectively. The subplots consisted of six species, including Eucalyptus camaldulensis Dehn, E. microtheca F. Muell., Acacia stenophylla, Fraxinus rotundifolia Miller. Populus euphratica Oliv.and Tamarix aphylla (L.) Karst.The results showed that the effects of irrigation treatments on survival and growth were not significant at first year of the trial. Resistance of the E. camaldulensis, species E. microtheca, A. stenophylla and T. aphylla to salinity and drought was good, whereas the resistance of F. rotundifolia to both environment conditions was not good and resistance of P. euphratica to salinity was excellent, but its resistance to drought was low. The tolerance of the species, E. camaldulensis, A. Stenophylla, E. microtheca and T. aphylla to frost (-9ºc) at the first year of the trial was low and the crown damage percentage was 80.8, 100, 31-6 and 97.1, respectively. E. microtheca was the most tolerant species due to its highest percentage of survival (88.3) at the end of the trial. The irrigation with drainage water had remarkable effects on tree growth and survival, particularly at summer