220 research outputs found

    Ranking the Cobalt Coating Nanostructures, Produced by Direct current Through the Analytic Hierarchy Process (AHP)

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    In recent years, cobalt coating has been known as an alternative material instead of chromium in corrosion and erosion resistant behavior. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of the cobalt coating has been calculated and ranked theoretically by the Analytic Hierarchy Process (AHP). For this purpose, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters on achieving nanostructure coating have been calculated. Then, by using the weights obtained, the relative priority of five available Co coatings was calculated and the quality of them was ranked. Among available Co coatings, the coating with 5 mA/ current density, pH 3, electrolyte saccharin of 0.25 grams per liter and a temperature of 45 °C during 30 minutes, in comparing with others had more favorable conditions for achieving nano-grain size. This shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488

    Ranking the Cobalt Coating Nanostructures, Produced by Direct current Through the Analytic Hierarchy Process (AHP)

    Get PDF
    In recent years, cobalt coating has been known as an alternative material instead of chromium in corrosion and erosion resistant behavior. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of the cobalt coating has been calculated and ranked theoretically by the Analytic Hierarchy Process (AHP). For this purpose, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters on achieving nanostructure coating have been calculated. Then, by using the weights obtained, the relative priority of five available Co coatings was calculated and the quality of them was ranked. Among available Co coatings, the coating with 5 mA/ current density, pH 3, electrolyte saccharin of 0.25 grams per liter and a temperature of 45 °C during 30 minutes, in comparing with others had more favorable conditions for achieving nano-grain size. This shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488

    Comparing the Ranking of Cobalt Coating Microstructures, Produced by Direct Current through Experimental Studies and the Analytic Hierarchy Process

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    In recent years, cobalt has been known as an alternative coating material to chromium in corrosion and erosion resistant applications. Extensive research has been carried out on a variety of electroplated cobalt coatings. In this study, for the first time, the relative priority of cobalt coatings has been evaluated by using the Analytic Hierarchy Process (AHP), in combination with empirical methods. In the first step, Cu substrates have been coated with Co under different experimental conditions. The SEM micrographs of Co coatings have been analyzed via image analysis (Clemex) software. In the second step, through the AHP and the Expert Choice software, benefiting from expert opinions, the relative weights of the effective parameters with an influence on microstructure have been calculated. Subsequently, by using the weights obtained, the relative priority of alternatives was calculated and the quality of coatings was ranked. The predicted ranking has been found to be in consistence with the experimental results. This result shows that before experimental tests, the best alternatives to achieve the ultimate goal could be anticipated. This anticipation leads to reduce in trial and error and the multiplicity of the tests in investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3096

    Investigating the relationship between low serum cholesterol and suicide in attempters with depression

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    Background & Objective: It has been postulated that depressed individuals with low total cholesterol levels may be more likely to die prematurely from suicide. This study aimed to examine the association between low serum cholesterol and suicide in depressed attempters. Materials & Methods: In this cross-sectional study, 180 suicide attempters, who met the inclusion criteria and were willing to participate in the study, were recruited in 2017. The data was collected using a demographic questionnaire and the Beck Depression Inventory-Second Edition (BDI-II). The blood cholesterol level was measured via an auto-analyzer. Results: The mean age was 26.39±10.75 years. The average cholesterol level in the moderate, severe, and serious depression groups was 151.30±35.23, 145.89±36.32, and 145.15±33.33, respectively. The mean age was higher in the group with a higher depression level, though the difference was not significant (P=0.06). The percentage of suicide attempts in single individuals was significantly higher (P=0.02). The mean cholesterol level in the group with the highest level of depression was the lowest, but the difference was insignificant (r=-.01, P=0.85). Only in females, the level of blood cholesterol showed a nearly significant difference between groups with different severities of depression (P=0.05). Cholesterol had a significant correlation with suicide frequency (P=0.008, r=0.28). Conclusion: Our results revealed no significant association between low serum cholesterol and suicide in attempters with depression; but low total serum cholesterol may be associated with depression and suicide in depressed subjects. Yet, more studies are required for verification of this causality. © 2020, Journal of Advances in Medical and Biomedical Research. All rights reserved

    Breeding ecology of the Iranian ground jay (Podoces pleskei)

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    Although Podoces pleskei is the only endemic bird of Iran, little information exists on its ecological features, population dynamics and threats that concern it. This species occurs in desert and semi desert areas, mostly on the Iranian plateau, though its range spreads southeast ward to the Iran- Pakistan border. In this research, a total of 52 nests were studied in three locations, the “Ghare Tappe”, “Marvast” and “Mehrano” region, from 2005 to 2008. Breeding habits, nest characteristics, hatching features, clutch size, length of incubation time, nesting period and features of the chicks were observed in the three locations and were analyzed using analysis of variance (ANOVA). To compare breeding success among the three study areas, Z test was applied. This bird builds its nest at the top of and within the denser parts of plants, particularly Atraphaxis spinosa, Ephedra intermedia and Zygophyllum eurypterum. At times of danger, they hide beneath shrubs. Z-tests showed that the breeding success of this bird varied between Marvast and Mehrano. The greatest cause of nest failure and chick mortality was the transcaspian desert monitor (Varanus griseus caspius), which feeds on the eggs and chicks.Key words: Breeding ecology, Pleske’s ground jay, nest characteristics, clutch size, nest success, threat

    Correlating low energy impact damage with changes in modal parameters: a preliminary study on composite beams

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    This paper is an experimental study of the effects of multi-site damage on the vibration response of a composite beam damaged by low energy impact. The variation of the modal parameters with different levels of impact energy and density of impact is studied. Specimens are impacted symmetrically in order to induce a global rate of damage. A damage detection tool Damage Index is introduced in order to verify the estimation of damping ratios. Design of Experiments is used to establish the sensitivity of both energy of impact and density of damage. The DOE analysis results (using natural frequency only) indicate that impact energy for 2nd, 3rd and 4th bending modes is the most significant factor contributing to the changes in the modal parameters for this kind of symmetrical dynamic test

    Comparison of pulmonary function test in school - Age children in clean and polluted air in Tehran, Iran

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    Background: Children seem to be more susceptible to deleterious effects of air pollution related to respiratory functional parameters as compared to adults and thus quite perceptively assessment of these pathological changes among children is necessary. The present study aimed to assess the effects of air pollution on respiratory functional parameters among primary school children in Tehran, Iran. Methods: This cross-sectional survey was performed on 102 children aged less than 12 years studying at a primary school in Tehran in 2015. At two time points with healthy and unhealthy air conditions (December 2015 and May 2016), all eligible children were evaluated with respect to respiratory functional parameters (FEV1, FEV1/FVC, FVC, PEF, FEF25-75) using a spirometer. Results: There were significant differences in respiratory some parameters including FEV1 (P = 0.013) and PEF (P = 0.003) between the two times of respiratory assessment, no difference was found in some others such as FVC, FEV1/FVC and FEF25-75. Conclusions: Air pollution can be harmful for respiratory functional status in children by reducing FEV1 and PEF parameters. © 2018, Iranian Journal of Pediatrics

    GPAQ-R: development and psychometric properties of a version of the general practice assessment questionnaire for use for revalidation by general practitioners in the UK.

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    BACKGROUND: The General Practice Assessment Questionnaire (GPAQ) has been widely used to assess patient experience in general practice in the UK since 2004. In 2013, new regulations were introduced by the General Medical Council (GMC) requiring UK doctors to undertake periodic revalidation, which includes assessment of patient experience for individual doctors. We describe the development of a new version of GPAQ - GPAQ-R which addresses the GMC's requirements for revalidation as well as additional NHS requirements for surveys that GPs may need to carry out in their own practices. METHODS: Questionnaires were given out by doctors or practice staff after routine consultations in line with the guidance given by the General Medical Council for surveys to be used for revalidation. Data analysis and practice reports were provided independently. RESULTS: Data were analysed for questionnaires from 7258 patients relating to 164 GPs in 29 general practices. Levels of missing data were generally low (typically 4.5-6%). The number of returned questionnaires required to achieve reliability of 0.7 were around 35 for individual doctor communication items and 29 for a composite score based on doctor communication items. This suggests that the responses to GPAQ-R had similar reliability to the GMC's own questionnaire and we recommend 30 completed GPAQ-R questionnaires are sufficient for revalidation purposes. However, where an initial screen raises concern, the survey might be repeated with 50 completed questionnaires in order to increase reliability. CONCLUSIONS: GPAQ-R is a development of a well-established patient experience questionnaire used in general practice in the UK since 2004. This new version can be recommended for use in order to meet the UK General Medical Council's requirements for surveys to be used in revalidation of doctors. It also meets the needs of GPs to ask about patient experience relating to aspects of practice care that are not specific to individual general practitioners (e.g. receptionists, telephone access) which meet other survey requirements of the National Health Service in England. Use of GPAQ-R has the potential to reduce the number of surveys that GPs need to carry out in their practices to meet the various regulatory requirements which they face

    Quality evaluation of national cancer registry system in Iran: Study protocol

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    Background: Cancer registry can be a very important component of health information system in developing countries. Routine collection of data and ongoing monitoring of their quality can have a crucial role in priority setting and evidence-based policy making for controlling cancers and trends follow-up in low and middle-income countries. Evaluation of cancer registered data consists of four important components including: comparability, completeness, validity, and timeliness. Similar frameworks are utilized in different countries all over the world.Methods and Materials: We will use the national annual cancer registry reports in Iran alone or perhaps along with other Iranian published reports about childhood cancer incidence to determine the stability and trend of incidence rates over time and compare above mentioned reports with childhood cancer incidence data reported by other countries through a systematic review as well as in some cases meta-analysis in order to assess data quality. Data will also be collected from other sources such as death certificates to estimate mortality rates and other different methods will also be additionally applied, by use of which death certificates would be utilized to assess the quality of data, too. Conclusion: As the first step for proper measuring incidence rate of all types of cancers all over the country, we will assess and evaluate reported national cancer registry data in Iran in order to estimate the national burden of cancers in 1990-2013

    Primary immunodeficiency disorders in Iran: Update and new insights from the third report of the national registry

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    Background: Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders mainly characterized by severe and recurrent infections and increased susceptibility to malignancies, lymphoproliferative and autoimmune conditions. National registries of PID disorders provide epidemiological data and increase the awareness of medical personnel as well as health care providers. Methods: This study presents the demographic data and clinical manifestations of Iranian PID patients who were diagnosed from March 2006 till the March of 2013 and were registered in Iranian PID Registry (IPIDR) after its second report of 2006. Results: A total number of 731 new PID patients (455 male and 276 female) from 14 medical centers were enrolled in the current study. Predominantly antibody deficiencies were the most common subcategory of PID (32.3 %) and were followed by combined immunodeficiencies (22.3 %), congenital defects of phagocyte number, function, or both (17.4 %), well-defined syndromes with immunodeficiency (17.2 %), autoinflammatory disorders (5.2 %), diseases of immune dysregulation (2.6 %), defects in innate immunity (1.6 %), and complement deficiencies (1.4 %). Severe combined immunodeficiency was the most common disorder (21.1 %). Other prevalent disorders were common variable immunodeficiency (14.9 %), hyper IgE syndrome (7.7 %), and selective IgA deficiency (7.5 %). Conclusions: Registration of Iranian PID patients increased the awareness of medical community of Iran and developed diagnostic and therapeutic techniques across more parts of the country. Further efforts must be taken by increasing the coverage of IPIDR via electronically registration and gradual referral system in order to provide better estimation of PID in Iran and reduce the number of undiagnosed cases. © 2014 Springer Science+Business Media
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