1,037 research outputs found
Simulation of Thermal Stratification and Salinity Using the Ce-Qual-W2 Model (Case Study: Mamloo Dam)
Due to the shortage of fresh water, the quality of stored water in reservoirs has become increasingly important. Thermal regime and salinity are factors that affect the quality of water reservoirs. These two parameters were studied in Mamloo Dam in Tehran province. This dam has recently started to be uses as a source of drinking water for Tehran and thus its water quality is of increased importance. In this regard, the hydrodynamic model for 2014 to 2015 was built and calibrated by the CE-QUAL-W2 model and the model was used to simulate the thermal regime and salinity up to 2020. Two main scenarios were studied in this period, the continuation of the current situation or a 2.5% increase in water requirements and 5% decrease in discharge. The results show that the reservoir will experience thermal stratification in the summer and vertical mixing in the winter. Dased on these results Mamloo reservoir is in branch of warm Monomictic lake. Also results showed that thermal stratification and ssalinity stratification dominates simultaneity. Besides this issue with 2.5% increase in water requirements and 5% decrease in discharge, duration of summer thermal stratification will decrease although intensity of thermal stratification will increase
The upper normal limit of serum alanine aminotransferase in Golestan Province, Northeast Iran
Background: The objective of this study was to determine the upper normal limit of serum alanine aminotransferase level in a population-based study in Golestan Province, northeast Iran. Methods: From the randomly invited individuals (2,292), 698 out of the 916 males and 1,351 out of the 1,376 females participated in the study (participation rate: 76.2 and 98.1, respectively). One hundred and twenty-one participants were excluded due to positive hepatitis B surface antigen or hepatitis C virus antibody and/or drinking more than 20 grams of alcohol per day. A total of 1,928 participants (1300 females) were included. The upper normal limit of serum alanine aminotransferase level was defined as the 95th percentile. Results: The upper normal limit of serum alanine aminotransferase level in normal weight and nondiabetics was significantly lower than the total study group (36 versus 45 U/L). Serum alanine aminotransferase level was independently associated with male gender, body mass index, and diabetes mellitus (OR=2.05; 95Cl: 1.44 - 2.94, OR=2.76; 95Cl: 1.84 - 4.13, and OR=2.96; 95Cl: 1.56-5.61, respectively). Conclusion: Considering the lower calculated upper normal limit in normal weight nondiabetic participants in this study, we recommend setting new upper normal limit for serum alanine aminotransferase level, It seems reasonable to set upper normal limit for serum alanine aminotransferase level in males and females separately
The upper normal limit of serum alanine aminotransferase in Golestan Province, Northeast Iran
Background: The objective of this study was to determine the upper normal limit of serum alanine aminotransferase level in a population-based study in Golestan Province, northeast Iran. Methods: From the randomly invited individuals (2,292), 698 out of the 916 males and 1,351 out of the 1,376 females participated in the study (participation rate: 76.2 and 98.1, respectively). One hundred and twenty-one participants were excluded due to positive hepatitis B surface antigen or hepatitis C virus antibody and/or drinking more than 20 grams of alcohol per day. A total of 1,928 participants (1300 females) were included. The upper normal limit of serum alanine aminotransferase level was defined as the 95th percentile. Results: The upper normal limit of serum alanine aminotransferase level in normal weight and nondiabetics was significantly lower than the total study group (36 versus 45 U/L). Serum alanine aminotransferase level was independently associated with male gender, body mass index, and diabetes mellitus (OR=2.05; 95Cl: 1.44 - 2.94, OR=2.76; 95Cl: 1.84 - 4.13, and OR=2.96; 95Cl: 1.56-5.61, respectively). Conclusion: Considering the lower calculated upper normal limit in normal weight nondiabetic participants in this study, we recommend setting new upper normal limit for serum alanine aminotransferase level, It seems reasonable to set upper normal limit for serum alanine aminotransferase level in males and females separately
SOME TROUBLE-MAKING ASPECTS OF LOAD FLOW ANALYSIS IN DISTRIBUTION SYSTEMS AND THEIR SOLUTIONS
ABSTRAC
The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran: A population-based study
Background: Hepatitis B virus infection is a very common cause of chronic liver disease worldwide. It is estimated that 3 of Iranians are chronically infected with hepatitis B virus. Current population-based studies on both rural and urban prevalence of hepatitis B virus infection in Iran are sparse with results that do not always agree. We performed this study to find the prevalence of hepatitis B surface antigen, anti-hepatitis B core antibody, and associated factors in the general population of three provinces of Iran. Methods: We randomly selected 6,583 subjects from three provinces in Iran, namely Tehran, Golestan, and Hormozgan. The subjects were aged between 18 and 65 years. Serum samples were tested for hepatitis B surface antigen and anti-hepatitis B core antibody. Various risk factors were recorded and multivariate analysis was performed. Results: The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran was 2.6 and 16.4, respectively. Predictors of hepatitis B surface antigen or anti-hepatitis B core antibody in multivariate analysis included older age, not having high-school diploma, living in a rural area, and liver disease in a family member. We did not find any significant differences between males and females. Conclusion: In spite of nationwide vaccination of newborns against hepatitis B virus since 1992, hepatitis B virus infection remains a very common cause of chronic liver disease in Iran which should be dealt with for at least the next 30-50 years
Defect Reduction with the Use of Seven Quality Control Tools for Productivity Improvement at an Automobile Company
The goal of zero defects is pursued by many manufacturing and service companies. In this regard, statistical tools are being used for defect reduction leading to productivity improvement. In this work, seven traditional QC tools (flow chart, check sheet, histogram, Pareto chart, cause, and effect diagram, scatter diagram and control chart) have been developed and implemented in an automobile company to assess and improve the defect reduction level in the assembly line. Chassis and trim lined were selected for data collection to assess and improve the defect level for productivity improvement. It was found from the results that after the successful implementation of the QC tools, the defect level reduced by 90% (from 132 to 13 defects) at the chassis line. Similarly, the defect level was reduced by 80% (from 157 to 28 defects) at the trim line. The automobile company implemented only a few of the seven QC tools in their assembly line. It is suggested that the company may need to manage a mechanism for the implementation of all seven QC tools in every section of the company
A Comparative Study of Power Distance of English Teachers and Non-English Teachers in Classroom Interaction in Iranian High Schools
This is the final version. Available on open access from Richtmann Publishing via the DOI in this recordSince cultural factors play a crucial role in creating behavioral patterns, investigating the relationship between English teachers and students can be a good index for discovering the level of power distance in the classroom environment with different cultures manifesting in their interactions. The current study has attempted to compare female high school students' viewpoints towards English teachers and non-English teachers in the Iran context to discover the difference in power distance between English and non-English teachers and their students. To this end, the present research was conducted in 3 high schools for females with female teachers, and the data was gathered through a five-item Likert scale questionnaire investigating students' viewpoints towards five main elements: Acceptability, Respect, Teaching method, behavioral patterns, and Friendship. The findings revealed a high power distance between English teachers and their students in an English class interaction than non-English teachers such as science teachers, math teachers, physics teachers, chemistry teachers, and art teachers and their students. In turn, the results implied positive viewpoints towards English teachers. Regarding four factors, Acceptability, Respect, Teaching method, and Behavior, there is a significant difference between the viewpoints towards English and non-English teachers. On the other hand, there is no significant difference between the two variables in terms of friendship
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