1,187 research outputs found

    Water supply and demand forecasting in the Zayandeh Rud Basin, Iran

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    Water demandWater supplyForecastingWater useRiver basinsReservoirsIranZayandeh Rud BasinChadegan Reservoir

    An overview of the hydrology of the Zayandeh Rud Basin

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    River basins / Hydrology / Water use / Reservoirs / Water balance / Climate / Irrigation systems / Iran / Esfahan Province / Zayandeh Rud Basin / Chadegan Reservoir

    Laboratory investigation of the impact of air pollution on partial discharge inception voltage of insulators in a specific region

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    Studying the discharge characteristics of transmission line insulators in the presence of pollution, particularly when the contaminated layer is wet by rain, fog or condensation, is necessary for selecting the proper insulation. Therefore, identifying the major air pollutants as well as the most effective ones on the discharge performance of outdoor insulators is mandatory. A systematic approach has been proposed to evaluate the impact of dominant air pollutants of an area on partial discharge (P.D) inception voltage of specimen insulators. Based on the suggested method, determining the pollution constituents, defining the dominant pollutant of the area, finding the most commonly used insulators for medium and above distribution voltages within the geographical boundaries of the Central Province of Iran, as well as examining the effect of dominant air pollutant of the region on partial discharge inception voltage of designated insulators by laboratory measurements, are the necessary steps toward a comprehensive study of the subject

    Water management for sustainable irrigated agriculture in the Zayandeh Rud Basin, Esfahan Province, Iran

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    Irrigation systemsCropping systemsIrrigated farmingRiver basinsTopographyGeomorphologyClimateHydrologyWater qualityGroundwaterSoil salinitySustainable agricultureIranEsfahan ProvinceZayandeh Rud BasinChadegan Reservoir

    Three Dimensional Dynamic Analysis of Alborz Dam with Asphalt and Clay Cores

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    Alborz rockfill dam with a clay core is under construction in North of Iran, an area of heavy rainfall. Because of the difficulties in the construction of a clay core in a wet area, an alternative for the watertight element (asphalt core) was considered. During the design of Alborz dam, a dynamic response analysis of the asphalt core was performed using two-dimensional modeling based on the equivalent linear method. Considering the shortage of study on the seismic behavior of asphalt core dams and also the high level of risk of earthquakes in Iran, it was necessary that the dynamic behavior of this dam was studied using three-dimensional models. In this study, the dynamic response of Alborz dam for both variants of clay and asphalt cores has been investigated and three-dimensional dynamic (non-linear) analyses have been carried out using the explicit finite-difference program, FLAC3-D, under various hazard levels of earthquakes (DBL and MCL). The results obtained included: time histories of the response acceleration, displacement, shear stress and shear strains are presented in this paper. The dynamic response of the dam with a clay core and asphalt core are compared with each other

    Investigation of Dynamic Behavior of Asphalt Core Dams

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    In this research, dynamic behavior of a rockfill dam with asphalt-concrete core has been studied utilizing numerical models and centrifuge model tests with material parameters determined by laboratory tests including static and cyclic triaxial tests and also wave velocity measurements. The case study selected is the Meyjaran asphalt core dam, recently constructed in Northern Iran, with 60 m height and 180 m crest length. The seismic response analyses have been performed using a non-linear three dimensional finite difference software under various hazard levels of earthquake loadings. Their results showed that the induced shear strains in the asphalt core are less than 1% during an earthquake with amax=0.25g and the asphalt core remains watertight. Also, the small scale physical models of the asphalt core dam have been tested on centrifuge, under impact loading and response accelerations and induced deformations were recorded by instruments installed within and on the models. The recorded data and observations of the centrifuge model tested at 80g acceleration showed that the induced deformations in the asphalt core under an impact load with a large acceleration of 7.6 m/s2 were very small. Comparing the results of centrifuge tests with the results of numerical dynamic analyses of a prototype dam indicated that the numerical results corresponded well with the data recorded during centrifuge tests

    Estimation of Water Requirement of Different Phenological Stages of Green Cumin Plant in Different Regions of Isfahan Province

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    IntroductionCumin (Cuminum cyminum L.) is an annual and herbaceous plant, with a vertical, round, narrow and branched stem, with a height of approximately 30-60 cm. This plant belongs to the Apiaceae family. This family is known for having plants with aromatic taste. Iran and some countries along the Mediterranean Sea are known as the primary origin for the cumin plant. In addition to Iran, cumin is cultivated in many countries such as Uzbekistan, Tajikistan, Turkey, Morocco, India, Syria, Mexico and Chile. About 300,000 tons of cumin seeds are produced in the world annually, of which China and Asian countries produce 70% and consume 90%. Short growing season (100 to 120 days), low water requirement and the possibility of rained cultivation, non-interference between cultivation and harvesting with other crops and no price fluctuation and proper economic justification are among the factors that interest farmers in cultivating this plant. In different regions, yields of 350 to more than 1000 kg of seeds are obtained from this plant, and 3350 cubic meters of pure water are needed for production. Materials and MethodsThis research was conducted in 2015 to 2017. The first year of the study included the collection and analysis of long-term climatic data of the region, and the second year included the implementation phase of the research. Analyzing meteorological data on the scale of decades and the cases of temperature, precipitation, wind speed, sunshine hours, relative humidity and evaporation from the pan were considered as criteria and by preparing the gradient equations, the rate of reference evaporation and transpiration was calculated. The required statistical information was obtained from 28 synoptic meteorological and climatology stations in Isfahan and some neighboring provinces. In the studies related to soil, apparent specific gravity and volumetric moisture content (field capacity and wilting point), soil salinity, soil texture and agricultural ability class of land in cultivation areas were considered. Soil-related information was used to calculate the soil evaporation coefficient (Ke), which describes the evaporation component in the trait (ETc). In fact, Ke is the basis for calculating the coefficient of reduction of evaporation from the surface layer (Kr) and the fraction of soil wet and exposed to air (few), and for its calculation, the presence of information related to soil characteristics is necessary. To calculate the soil characteristics, in addition to sampling from the fields in the research, the database of 1600 soil profiles in the soil and water research department of Isfahan province was also used. Results and DiscussionThe results showed that 18 cities in Isfahan province had cumin cultivation potential, which had a significant difference in terms of pure water requirement per hectare (5% level) and water consumption at different phenological stages (1% statistical level). In terms of water requirement per hectare, the cities of Isfahan province can be divided into three groups. Average water requirement per hectare in the first group (the cities of Golpayegan, Lenjan, Tiran and Karvan, Shahin and Shahr and Mime), the second group (the cities of Isfahan, Khomeini Shahr, Falavarjan, Shahreza, Kashan, Najaf Abad, Natanz), Mobarake, Dehaghan and Borkhar), and the third group (Aran and Bidgol, Ardestan, Khoor and Biabanak and Nain) were equal to 3000, 3240 and 3770 m-3 ha-1, respectively. The water requirement of the growth development stage in the cities of the third group was equal to 2029 m-3 ha-1, which was significantly different from the cities of the first and second groups (p < 1% level). According to the results, cumin might be a suitable plant for crop rotations in Isfahan province due to its low water requirement and tolerance to moisture stress. ConclusionThe water requirement for cultivating cumin in various regions of the province is notably lower compared to many common crops, such as wheat, barley, and safflower. In 10 out of the 18 cities included in the study, significant water savings of up to 3,240 cubic meters per hectare can be achieved by optimizing water transfer efficiency. For cumin cultivation, this water conservation can even reach 3,000 cubic meters in cities with cooler climates. Surprisingly, in the hot areas of Isfahan province, including Ardestan, Nain, Khoor, Biabanak, Aran, and Bidgol, it is feasible to grow cumin with a water consumption of just 3,770 cubic meters per hectare

    Autophagy in dental tissues: a double-edged sword

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    Biotechnology and Biological Sciences Research Council [BB/L02392X/1]SCI(E)PubMedEDITORIAL [email protected]

    Population dynamics of HCV subtypes in injecting drug‐users on methadone maintenance treatment in China associated with economic and health reform

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    The extensive genetic heterogeneity of hepatitis C virus (HCV) requires in-depth understanding of the population dynamics of different viral subtypes for more effective control of epidemic outbreaks. We analyzed HCV sequences data from 125 participants in Wuhan, China. These participants were newly infected by subtype 1b (n=13), 3a (n=15), 3b (n=50), and 6a (n=39) while on methadone maintenance treatment (MMT). Bayesian phylogenies and demographic histories were inferred for these subtypes. Participants infected with HCV-1b and 3a were clustered in well-supported monophyletic clades, indicating local sub-epidemics. Subtypes 3b and 6a strains were intermixed with other Chinese isolates, as well as isolates from other Asian countries, reflecting ongoing across geographic boundary transmissions. Subtypes 1b and 3a declined continuously during the past ten years, consistent with the health and economic reform in China, while subtype 3b showed ongoing exponential growth and 6a was characterized by several epidemic waves, possibly related to the recently growing number of travelers between China and other Asian countries. In conclusion, results of this study suggest that HCV subtype 3b and 6a sub-epidemics in China are currently not under control, and new epidemic waves may emerge given the rapid increase in international traveling following substantial economic growth. This article is protected by copyright. All rights reserved
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