Mechanical and Shielding Properties of Concrete Subject to Gamma-ray

 In this research, concrete with different percentages of 0, 10, 25, 50, 75 and 100 of barite powder and 10% of graphite powder were investigated for the study of gamma protective properties. The transmitted fluxes of gamma-rays that were emitted from Cs-137 source were detected by a NaI(Tl) detector and analyzed by an MCA analyzer. Then, the samples were tested for compressive strength, tensile strength, ultrasonic pulse wave velocity and the linear attenuation coefficients. By comparing the obtained samples, it was observed that a sample containing 10% barite powder plus 10% graphite powder could be used as a protective material against gamma rays

Relationship between information asymmetry and cost of capital

Shareholders expected return is normally impacted by informational risk and informational asymmetry, on the other hand, creates informational risk. Thus, investors demand greater risk premium in the case of informational asymmetry and in turn corporate expenditures increase. In this study, we determine the relationship between informational asymmetry and capital cost. The study uses information of 109 companies listed in Tehran Securities Exchange over the period of 2005-2010 and the results suggest a positive and significant relationship between informational asymmetry and capital cost. In addition, the results from present research indicate that when capital markets are competitive, there is not a significant relationship between informational asymmetry and capital cost. But when markets are partially competitive there is a significant relationship between informational asymmetry and capital cost

Application of response surface methodology for the photo degradation of dye using ZnO nanorods loaded on the activated carbon

In this work, ZnO with a nanorod morphology loaded on activated carbon (ZnO NRs-AC) was synthesized using the co-precipitation method for the photo-degradation of malachite green (MG) under the UV light. The photo-catalyst was characterized using various analytical techniques including XRD and FE-SEM. The Box-Behnken design (BBD) combined with the response surface methodology (RSM) was applied for the optimization of the influential parameters. The optimum values for the parameters involved were as follow: photo-catalyst dosage,16 mg; MG concentration, 30 mg L-1; and reaction time was 46 min. Studying the effect of foreign ions on the performance of the photo-catalytic process indicated the stability of ZnO NRs-AC in the photo-catalytic degradation of MG. According to the Langmuir–Hinshelwood (L–H) kinetic model, the kinetic degradation of MG followed a pseudo-first order kinetic model

Evaluation of Sustainable Agricultural Development in Golestan Province

Sustainable agriculture is a scientific activity, based on ecological principles that its main purpose is to create balance and sustainability in production systems. In order to assess the status of sustainable agricultural development in Golestan province, relative advantage assessment of support systems was used. For this purpose, five support systems are constructed, including agricultural resources, agricultural development, environment and ecosystems, rural societies and sciences, education and management based on 54 indicators. In final, status of sustainable agriculture developmant of 14 townships in Golestan province was calculated by sum of these support systems. Then, the status of sustainable agriculture were zoning in ArcMap media in 6 classes (high sustainable, moderate sustainable, weak sustainable, weak unsustainable, moderate unsustainable and high unsustainable). The results showed that Golestan province was weak in terms of sustainability in agriculture resources, agriculture development, environment and ecosystems and sciences, education and management, but it hadweak unsustainable in term of rural societies. In general, it can be stated that Gorgan and Gonbad-Kavous townships had the highest sustainability in some indexes. Also, Gomishan was identified as most unsustainable township in comparison with other townships in all studied indexes except rural societies and science, education and management. The results of sustainable agriculture development showed that Golestan province had unsustainable or weak sustainable status in development of sustainable agriculture, because only 5 townships from 14 townships had high and moderate sustainable and others townships were classfied in weak sustainability or un-sustainability classes

Predictors of appropriate ICD therapy in patients with implantable cardioverter-defibrillator

BACKGROUND: Understanding the predictors of appropriate implantable cardioverter defibrillator (ICD) therapy could help to better identify candidates for ICD implantation. METHODS: One hundred and sixty two patients with ICD (111 with coronary artery disease [CAD] and 51 with dilated cardiomyopathy [DCM]) were included in the study. Clinical, electrocardiographic, and ICD stored data and electrograms were collected. RESULTS: During mean follow up of 15±11 months 54 patients (33%) received ≥ 1 appropriate ICD therapy (AICDT). We used binary logistic regression analysis with forward selection method to find the potential predictors of appropriate ICD therapy after device implantation. Male gender (odds ratio [OR] = 2.76, 95% confidence interval [CI] = 1.1 – 7.1, P=0.021), DCM as underlying heart disease (OR = 4.2, 95% CI = 1.9 – 9.5, P=0.001), and QRS width > 100 ms (OR = 2.58, 95% CI = 1.2 – 5.4, P=0.010) were correlated with increased likelihood of AICDT during the follow up period. In subgroup analysis of the patients with CAD and DCM, QRS duration > 100 ms was correlated with the probability of ≥ 1 AICDT. In our patients indication of ICD implantation (primary versus secondary prevention) did not influence probability of ≥ 1 AICDT (adjusted OR = 1.66, 95% CI = 0.7 – 4.0, Mantel-Haenszel P value P=0.355.) CONCLUSION: QRS width could be used as an additional simple risk stratifier beyond EF to identify potential candidates who would benefit more from ICD implantation. This may have practical implications for patient selection especially in developing countries. Indication of ICD implantation (primary versus secondary prevention) did not affect the probability of ≥ 1 AICDT during the follow up period

Sensitivity And Specificity of FEF25–75/Forced Vital Capacity for Diagnosing Restrictive Lung Disease

Introduction and objective: The role of spirometry in the diagnosis of restrictive lung diseases is unclear. This study investigated the sensitivity and specificity of the forced expiratory flow 25–75 (FEF25–75)/forced vital capacity (FVC) parameter in diagnosing restrictive lung disease. Methods: In this study, the records of all restrictive patients who were referred to the pulmonary centre of Imam Khomeini Hospital, Tehran, Iran, from March 2021–March 2022 have been reviewed, and the indexes in the body box and spirometry have been recorded. Results: A total of 527 people were included in the study. Among them, 134 people (25.4%) had restrictive lung disease. The average area under the graph of the FEF25–75/FVC index is 0.648±0.028. It can be said that the area under the graph for the FEF25–75/FVC index is between 0.594–0.703. The FEF25–75/FVC index at values above 79.90 has a sensitivity of 70.9% and a false positive rate (1- specificity) of 53.2%. Conclusions: According to the result of this study, the ratio of FEF25–75/FVC index in spirometry at above 79.90 has a sensitivity of 70.9% and a false positive rate (1- specificity) of 53.2%. Therefore, it can be used as a screening test for restrictive lung diseases