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INTRODUCTION: Resilient schools can warranty students' health and survival at disasters. It is obligatory that schools be prepared for natural challenges through local programs. Considering the great population of students, disaster-resilient schools can be a safe and suitable environment for students at the time of disaster. OBJECTIVE: This study aims to identify certain operational strategies for establishing schools resilient to natural disasters. METHOD: This qualitative study was based on conventional content analysis. Using purposive sampling method, 24 experts in the fields of health in disasters, construction engineering, psychology, teaching, and administrative management participated in the study. Maximum variation sampling continued until data saturation was achieved. The data collected via unstructured interviews were analyzed with Graneheim and Lundmen's conventional content analysis. RESULTS: Content analysis resulted in four main categories as operational strategies for establishing disaster-resilient schools including: 1) "construction and non-construction optimization", with four subcategories of construct risk management, optimization of construct architecture and physical structure, correct construct localization, and promotion of non-construct safety, 2) "promotion of organizational coordination and interactions" with two subcategories, namely improvement in intra-organizational communication and improvement in extra-organizational communication, 3) "improvement in education" with three subcategories of holding educational courses for families and students, holding educational courses for managers and personnel, and holding simulated exercises, and 4) "process promotion" with four subcategories of increased preparedness, correct planning, creation of organizational structure, and rehabilitation facilitation. CONCLUSION: Various factors affecting schools' response to disasters form operational strategies to establish disaster-resilient schools. These strategies influence pre- and post-disaster preparedness. Awareness of these components followed by preparedness prior to disasters can save students' lives, improve school performance after disasters, and aid in establishing disaster-resilient schools as safe lodgings.
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The efficiency of photocatalytic oxidation process in arsenite (As(III)) removal from contaminated water by a new Fe2O3-Mn2O3 nanocomposite under UVA radiation was investigated. The effect of nanocomposite dosage, pH and initial As(III) concentration on the photocatalytic oxidation of As(III) were studied by experimental design. The synthesized nanocomposite had a uniform and spherical morphological structure and contained 49.83% of Fe2O3 and 29.36% of Mn2O3. Based on the experimental design model, in photocatalytic oxidation process, the effect of pH was higher than other parameters. At nanocomposite concentrations of more than 12â¯mgâ¯L-1, pH 4 to 6 and oxidation time of 30â¯min, photocatalytic oxidation efficiency was more than 95% for initial As(III) concentration of less than 500⯵gâ¯L-1. By decreasing pH and increasing the nanocomposite concentration, the photocatalytic oxidation efficiency was increased. Furthermore, by increasing the oxidation time from 10 to 240â¯min, in addition to oxidation of As(III) to arsenate (As(V)), the residual As(V) was adsorbed on the Fe2O3-Mn2O3 nanocomposite and total As concentration was decreased. Therefore, Fe2O3-Mn2O3 nanocomposite as a bimetal oxide, at low doses and short time, can enhance and improve the efficiency of the photocatalytic oxidation and adsorption of As(III) from contaminated water resources. Furthermore, the energy and material costs of the UVA/Fe2O3-Mn2O3 system for photocatalytic oxidation of 1â¯â¯mgâ¯L-1 As(III) in the 1â¯L laboratory scale reactor was 0.0051 .
Assuntos
Arsenitos/química , Compostos Ferrosos/química , Compostos de Manganês/química , Nanocompostos/química , Óxidos/química , Raios Ultravioleta , Poluentes Químicos da Água/química , Purificação da Água/normas , Adsorção , Arsenitos/isolamento & purificação , Oxirredução , Processos Fotoquímicos , Projetos de Pesquisa , Titânio/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodosRESUMO
In this study, the efficiency of Integrated Fixed-film Activated Sludge (IFAS) system in synthetic greywater treatment and nutrients removal was studied in duration of 105 days according to different Organic Loadings Rates (OLRs). The study was operated in pilot-scale and OLRs of 0.11-1.3 gCOD/L.d. Scanning Electron Microscope (SEM) image showed that the biofilm with a proper thickness was formed on IFAS reactor's media. The results indicated that the best removal efficiency of BOD5, COD, and TSS were 85.24, 92.52 and 90.21%, respectively, in an organic loading of 0.44 gCOD/L.d. Then, with the OLR increased, the removal efficiencies of BOD5, COD, and TSS increased as long as the organic loading reached 0.44 gCOD/L.d. But with the OLR increased more, the removal efficiency of these parameters decreased. The ANOVA statistical test results showed that the mean difference of removal efficiency in organic loadings for BOD5 (p ≤ 0.001) and COD (p = 0.003) was significant, while it was insignificant for TSS (p = 0.23). The best removal efficiencies of Total Nitrogen (TN) and Total Phosphorus (TP) were 89.60 and 86.67%, respectively, which were obtained at an OLR of 0.44 gCOD/L.d. By increasing OLR up to 0.44 gCOD/L.d, removal efficiencies of TN and TP increased, while the removal efficiency decreased with the OLR increased more, and this difference was statistically significant (p = 0.021). Finally, the results showed that the IFAS system provided a proper efficiency in treatment of the synthetic greywater and it could be used in a full scale.
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BACKGROUND/AIMS: Patient assessment by imaging studies using contrast media is currently replacing open procedures, especially in high-risk patients. However, the use of such contrast media might result in acute events and injuries after the procedure. In the present study, we first determined the incidence of contrast-induced nephropathy (CIN) in a sample of Iranian patients who candidated for coronary angiography and/or angioplasty, and then assessed major risk factors predicting the appearance of CIN following these procedures. METHODS: Two hundred and fifty consecutive, eligible patients scheduled for coronary angiography and/or angioplasty at the Afshar Hospital in Yazd between January 2009 and August 2010 were considered for enrollment. Renal function was measured at baseline and 48 h after the intervention, and CIN was defined by an increase in creatinine of >0.5 mg/dl or 25% of the initial value. The predictive role of potential risk factors was determined in a multivariate model adjusted for comorbidities, preexisting renal impairment, and angiographic data. RESULTS: CIN following coronary angiography or angioplasty appeared in 12.8% of the cases. A myocardial infarction before the procedure (OR = 2.121, p = 0.036) and a prior history of hypertension (OR = 2.789, p = 0.025) predicted the appearance of acute renal failure following angiography or subsequent angioplasty. A low estimated glomerular filtration rate at baseline slightly predicted CIN after these interventions. CONCLUSION: Transient acute renal dysfunction occurred in 12.8% of the patients within 48 h after angiography or subsequent angioplasty and could be predicted by a myocardial infarction before the procedure or by a prior history of systolic hypertension.