86 research outputs found

    SPS TURBULENT MODELING OF HIGH SPEED TRANSOM STERN FLOW

    Get PDF
    Transom stern flow is a complicated fluid flow phenomenon especially at high speed regime. Therefore, various authors have studied the transom stern flow, both numerically and experimentally. Smoothed Particle Hydrodynamics method can be considered as a good choice for simulation of nonlinear physics related to the transom flow. Accordingly, SPH as a meshless, Lagrangian, and particle method is presented in this article and SPS turbulent model is also included for more accurate solution. For density modification, a second order density filter scheme is employed. For validation of numerical setup, several draft based Froude numbers are considered and it is shown that SPH solution is in good agreement with available experimental data. Furthermore, three longitudinal Froude number are investigated for high speed transom flow simulation. High speed cases are compared with Savitsky’s formula and it is observed that at high speeds, SPH solutions are also reasonable

    Treatment of Ankyloglossia with Carbon Dioxide (CO2) Laser in a Pediatric Patient

    Get PDF
    INTRODUCTION: Laser surgery as an alternative for conventional surgical procedure has gained special attention. Using Carbon Dioxide (CO2) laser has some benefits like less post-operative pain, swelling and infection, decrease in risk of metastasis and edema, and less bleeding providing dry sites for surgery.CASE REPORT: A 12 years old boy with lingual frenum with indication for excision was referred to the laser department of Tehran University of medical sciences dental school. CO2 laser was used with 10600 nm wavelength, 1.5 W output power, 100 Hz frequency and 400 μsec pulse duration in non-contact mode.RESULTS: The result of using CO2 laser was dry and bloodless field during operation, no post operative swelling, no pain or discomfort, with normal healing process.CONCLUSION: We suggest and stimulate the use of CO2 laser for soft tissue surgery because of elimination of suture, convenient coagulation, time saving, patients’ comfort and easy manipulation

    SPS TURBULENT MODELING OF HIGH SPEED TRANSOM STERN FLOW

    Get PDF
    Transom stern flow is a complicated fluid flow phenomenon especially at high speed regime. Therefore, various authors have studied the transom stern flow, both numerically and experimentally. Smoothed Particle Hydrodynamics method can be considered as a good choice for simulation of nonlinear physics related to the transom flow. Accordingly, SPH as a meshless, Lagrangian, and particle method is presented in this article and SPS turbulent model is also included for more accurate solution. For density modification, a second order density filter scheme is employed. For validation of numerical setup, several draft based Froude numbers are considered and it is shown that SPH solution is in good agreement with available experimental data. Furthermore, three longitudinal Froude number are investigated for high speed transom flow simulation. High speed cases are compared with Savitsky’s formula and it is observed that at high speeds, SPH solutions are also reasonable

    Designing an InGaP/InAlGaP Double Junction Solar Cell without an Anti-Reflection Coating by Adding a New Window Layer in the Upper Junction and Optimizing the Back Surface Field Layer

    Get PDF
    Abstract: The present study proposes a novel indium gallium phosphide/aluminum gallium indium phosphide (InGaP/InAlGaP) double junction solar cell without an anti-reflection coating that includes an upper InGaP cell, a lower InAlGaP cell, and a gallium arsenide (GaAs) tunnel junction. To increase the efficiency of the cell, a new window layer was used at the upper junction. To achieve higher efficiency, the researchers also optimized the back surface field layer of the lower cell. The results were analyzed via numerical modeling with Silvaco/Atlas software under the AM1.5 radiation spectrum. Findings suggested that using the sun=1 parameter, the obtained maximum values of short-circuit current, open-circuit voltage, fill factor, and efficiency parameters for the proposed solar cell structure were Jsc = 24.078 mA/cm2, Voc = 3.41886, FF = 91.1836, and Eff = 71.721%, respectively

    Genetic analysis of semen from different origins and their impact on production traits: A single and multiple trait approach

    Get PDF
    This study aims to evaluate the genetics of imported semen and assess the genetic trend of production traits in Holstein cows during their first lactation in Iran. The data was collected from 28 different herds in Isfahan province between 2011 and 2020. Variance-covariance components were estimated by the restricted maximum likelihood method and the single and multi-trait animal model. The correlation between breeding values for bulls reported in catalogs and estimated in this was calculated. The mean of the least squares by countries shows that the daughters of Spanish bulls have the highest average for milk production, and the daughters of German, French, Spanish, and American bulls have the highest average percentage of fat and protein and the amount of fat and protein, respectively. Estimated heritability for milk production, fat, and protein percentage, and the amount of fat and protein were 0.34±0.011, 0.48±0.021, 0.41±0.016, 0.40±0.090, and 0.39±0.010 respectively. The mean genetic trend of milk production, fat percentage, protein percentage, fat content, and protein content were 92, 0.010, 0.004, 1.73, and 2.52, respectively. The correlation between the estimated and reported breeding value of bulls for milk production trait, percentage of fat and protein, and the amount of fat and protein was estimated at 0.48, 0.67, 0.69, 0.14, and 0.26, and all of the estimated correlations are statistically significant at the level of 0.05. Based on the results for the most critical production trait in Isfahan herds, milk production, American bulls have the best performance and genetic trend

    Design and psychometric evaluation of epilepsy-related apathy scale (E-RAS) in adults with epilepsy: a sequential exploratory mixed methods design

    Get PDF
    Background: Apathy in patients with epilepsy is associated with a wide range of consequences that reduce the patient�s ability to perform social functions and participate in self-care and rehabilitation programs. Therefore, apathy is one of the important diagnoses of the healthcare team in the process of caring for epileptic patients and its dimensions need to be examined and recognized. Therefore, appropriate instruments with the sociocultural milieu of each community should be provided to health care providers. The aim of the present study was to design and measure epilepsy�related apathy scale (E-RAS) in adults with epilepsy. Methods: This study of sequential exploratory mixed methods design was conducted in Iran from April 2019 to December 2019. In the Item generation stage, two inductive (face-to-face and semi-structured interviews with 17 adult epileptic patients) and deductive (literature review) were used. In item reduction, integration of qualitative and literature reviews and scale evaluation were accomplished. For Scale Evaluation, face, content, construct exploratory factor analysis (EFA) (n = 360) and confirmatory factor analysis (CFA) (n = 200), convergent and divergent Validity and reliability (internal consistency and stability) were investigated. Results: The results of EFA showed that E-RAS has four factors, namely, motivation; self-regulatory; cognition and emotional-effective. These four latent factors accounted for a total of 48.351% of the total variance in the E-RAS construct. The results of CFA showed that the 4-factor model of E-RAS has the highest fit with the data. The results of convergent and divergent validity showed that the values of composite reliability (CR) and average variance extracted (AVE) for the four factors were greater than 0.7 and 0.5, respectively, and the value of AVE for each factor was greater than CR. The Cronbach�s alpha coefficient for the whole scale was obtained 0.815. The results of the test-retest showed that there was a significant agreement between the test and retest scores (P < 0.001). Conclusion: E-RAS is a multidimensional construct consisting of 24 items, and has acceptable validity and reliability for the study of epilepsy-related apathy in adult epileptic patients

    Association of Diabetic Retinopathy and Sleep Quality

    Get PDF
    Sleep disorders are more common in diabetes mellitus (DM) cases rather than normal ones. In addition, this condition could be associated with diabetic retinopathy (DR) development with more inflammatory indices in circulation. In the present study, we have evaluated the association between DR and sleep quality. This cross-sectional study is a part of the second phase of the study of the elderly cohort of Amirkola City, which was conducted in 2015-2016 on all people aged 60 and higher. Of all diabetic cases, 44 cases had retinopathy and were selected as the case group. To compare two control groups, 135 diabetic patients without retinopathy and 135 people without diabetes were randomly selected. The presence and type of retinopathy were determined based on an eye physical examination by an ophthalmologist. In addition, sleep quality was evaluated based on the Pittsburgh Questionnaire. The obtained data were analyzed by ANOVA, t-test, and linear regression tests. In the present study, there was a significant difference in the score of the Pittsburgh questionnaire between people with DR (45.5±68.2) compared to diabetic people without retinopathy (76.5±48.2) and people without diabetes (95.4±36.2) (P=0.470), but diabetic people without retinopathy had significantly worse sleep quality than people without diabetes (P=0.019). Also, sleep quality in women with DR was worse than in men (P=014). In the linear regression analysis, it was observed that age, gender, diabetes, and history of depression significantly affect the sleep quality of the evaluated cases (P<0.05 for all). According to the results of the present study, DR does not negatively influence the quality of sleep, and DR is not related to sleep disorders

    Age-Specific Distribution of Intraocular Pressure in Elderly Iranian Population and Its Associated Factors

    Get PDF
    Background: The purpose of this study was to determine the distribution of intraocular pressure (IOP) and assess its association with age, sex, systemic blood pressure, diabetes mellitus, body mass index (BMI) and tobacco smoking in Iranian elderly population. Methods: This cohort-based, cross-sectional study assessed elderly individuals aged 60-90 years in Amirkola, northern Iran, in 2016-2017. Past medical history, blood pressure, diabetes mellitus, BMI and tobacco smoking were recorded through an interview and physical examination. IOP was assessed using non-contact tonometry. Results: Total of 1377 individuals participated in this study, out of which 1346 IOP measurements were included for the final analysis. The mean age of participants was 69.4 &#177; 7.1 years and mean IOP was determined to be 16.7 &#177; 3.2 mmHg. Majority of the participants were males (56.1 vs 43.1), 73.8 of participants were overweight or obese, 6.1 smoked tobacco, 28.9 had diabetes mellitus and 84.9 had higher than normal blood pressure. Through multiple regression analysis, it was determined that age (&#946;=-0.132, p&#60;0.001) was negatively associated with IOP, and the presence of diabetes mellitus (&#946;=0.118, p&#60;0.001), systolic blood pressure (&#946;=0.101, p&#60;0.001), and BMI (&#946;=0.020, P=0.020) were positively associated with IOP. Conclusion: Mean IOP of individuals in this study was higher than average based on other studies. Age, was negatively and systemic blood pressure, BMI and presence of diabetes mellitus were positively associated with mean IOP of elderly Iranian population. Sex and tobacco smoking were not correlated with IOP. &#160

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

    Get PDF
    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

    Get PDF
    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens
    corecore