Investigation of riprap stability of a dam : risk assessment by InSAR method and rock mechanical test

Riprap resistance is a widely used solution for protecting earth dams from erosion but riprap can be displaced on the dam surface. This study examines the stability of riprap in the Taleqan Dam, Iran using rock mechanical tests and InSAR technology. Uplift of dam stairs and erosion of the riprap material have been observed during field work at the study site, and samples have been gathered from three rock categories. The purpose of this study is to explore the factors influencing the deformation of the Taleqan Dam. The InSAR method has been employed for monitoring surface deformation and the Los Angeles ASTM C test was used to establish the cause of dam deformation. InSAR analysis was carried out using Sentinel-1A images from 2014 to 2019. The results revealed subsidence at an average rate of 4 mm/yr over that period. The results of Los Angeles ASTM C indicated that the Andesite riprap was more easily eroded, has a relatively low durability and specific weight, and low resistance erosion. Therefore it is unsuitable for use as a protection layer for the crest and lower sectors of the riprap. It can also be concluded that the inadequate durability of certain rock materials may potentially cause weathering, depression, reduced thickness and displacement of the riprap.Peer reviewe

An overview of the water remediation potential of nanomaterials and their ecotoxicological impacts

Nanomaterials, i.e., those materials which have at least one dimension in the 1-100 nm size range, have produced a new generation of technologies for water purification. This includes nanosized adsorbents, nanomembranes, photocatalysts, etc. On the other hand, their uncontrolled release can potentially endanger biota in various environmental domains such as soil and water systems. In this review, we point out the opportunities created by the use of nanomaterials for water remediation and also the adverse effects of such small potential pollutants on the environment. While there is still a large need to further identify the potential hazards of nanomaterials through extensive lab or even field studies, an overview on the current knowledge about the pros and cons of such systems should be helpful for their better implementation.Peer reviewe

Association of Diabetic Retinopathy and Sleep Quality

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

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