Showing 8 results for Mohammad Kari
Volume 1, Issue 2 (6-2013)
Abstract
Concentrations of lead (Pb) were found in the shells of the oyster Saccostrea cucullata and sediments in May 2010. Samples were obtained at four sites on Qeshm Island, at three sites on Hormoz Island, and at three sites in Lengeh Port along the intertidal coast of the Persian Gulf of Iran. The levels of Pb in sediments and shells were analyzed by graphite furnace atomic absorption spectrophotometer.Mean Pb concentrations in the different sampling stations varied between 613.94 and 0.06 µg g-1 in the shells of S. cucullata and 180.78 and 0.86µg g-1 in sediments. Biological effects criteria suggest that Pb concentrations in sediments in three sites from Lengeh Port were higher than ERL (effects range low), but at the all sites were lower than ERM (effects range medium). The present results support the significant differences in shell and sediments’ accumulated concentrations of Pb among sites attributed to input sources of human activities including urban, domestic, industrial, agricultural, shipping and transport, mining activities, and ports and harbors
Volume 5, Issue 4 (2015 2016)
Abstract
Sara Gilani, Behrouz Mohammad Kari,
Volume 11, Issue 2 (9-2011)
Abstract
Solar energy can be utilized through different types of passive and active solar systems. One of the passive systems is the Greenhouse that provides different functions. In this research, heating performance of Greenhouse in cold climate is simulated, investigated, and analyzed by means of computer software.
The results of this research showed that Greenhouse, in comparison with Direct Gain glazing system, decreases building heating load, despite the diminution of the direct radiation gains. In Ardebil, the optimal building orientation, in order to get the maximum solar gain and the minimum load in the heating period, is obtained in south west and west direction of the facade. The maximum heat loss and minimum solar gain occur through the north side of the building, which is considered as the most inappropriate facade direction for the Greenhouse system.
Mahdieh Abravesh, Behrouz Mohammad Kari, Shahin Heidari,
Volume 15, Issue 8 (10-2015)
Abstract
Considering the determinant role of glazing systems in energy consumption, it is imperative to survey the thermal performance of double coated glazing systems in accordance with the harsh climatic conditions and available local and foreign products' situation. In this paper, the radiative properties of local coated and non-coated glazing units are measured by the spectrophotometer and emissometer apparatus. These thermal and solar properties were not available in any datasheet. In the second step, through the accurate calculation method of EnergyPlus software, the amount of energy loss due to the radiative properties of glazing units was simulated in two extreme climates (very hot and humid climate and cold climate). By choosing the simulation method instead of real measurements in this step, it became possible to evaluate the effect of different parameters (such as climate, orientation and glazing specification) on the annual energy loss through the glazing units by eliminating other factors like energy transfer through opaque surfaces and ventilation. The simulation results indicate that using double glazing unit with low-E coating on the third surface (from the exterior) of the double glazing, significantly reduces energy consumption of the glass unit (up to 97 percent) for all orientations in the cold climate. In hot climates like Bandarabbas, using reflective coatings (with dark blue color) in double glazing units is the best possible alternative since it lessens the energy transfer through the glass unit (up to 70 percent) compared to the clear double glazed ones.
Danial Hakimirad, Mehdi Maerefat, Behrouz Mohammad Kari,
Volume 16, Issue 13 (Conference Special Issue 2017)
Abstract
Danial Hakimi Rad, Mehdi Marefat, Behrouz Mohammad Kari,
Volume 17, Issue 2 (3-2017)
Abstract
Estimating indoor air pollutants to ensure the air quality is very important. In this study, a conventional residential space is numerically simulated in order to investigate the behavior of pollutants. Using the numerical results and the experimental results of other references, proposed the analytical relation to estimate the concentration of CO2 in term of factors such as CO2 produced by breathing residents or combustion equipment, the volume of space and ventilation rate. The results of the analytical relation are full compliance with experimental and numerical results and it can be used to estimate indoor air quality. Proposed relation can be used in all the same cases.
Seyyed Mohammad Reza Maleki, Behrooz Mohammad Kari, Mehdi Maerefat,
Volume 17, Issue 4 (6-2017)
Abstract
Courtyard has been recognized as one of main elements in the Iranian culture, architecture and building design. According to its micro-climate effect in improving thermal performance of building, courtyard has been considered as a considerable subject for many researches. This paper investigates the courtyard’s design parameters and geometric configurations in pre-design states for improving thermal performance and comfort. For achieving this point, in this research the influence of courtyard orientation, horizontal dimensions and other parameters related to geometry have been evaluated. Due to micro-climate effect of courtyard on parameters related to thermal comfort, three main geometric layouts such as closed, semi-closed and open geometry have been investigated and compared by CFD simulations in ENVI-met software. The thermal comfort parameters are also investigated through comparing mean PMV in all simulations cases, using Fanger’s extended model. The results showed that thermal performance of closed shaped courtyard is better than other layouts. Also the comparison of results related to different aspect ratios (length to width ratios), put into evidence that thermal performance improves as the aspect ratio gets close to 1. That means as the courtyard shape encloses to square, the thermal performance improves and the mean air temperature in the investigated microclimates declines. To determine best configuration for Tehran’s climate, the results showed north-south orientation of building and increase of the height of the courtyard, are the two most appropriate considerations that will directly improve the thermal performance and comfort, specifically in closed and semi-closed layout.
M. Akbari Paydar, B. Mohammad Kari, M. Maerefat, M. Abravesh,
Volume 19, Issue 6 (June 2019)
Abstract
The optimal insulation thickness is a function of the insulation initial cost and the cost of energy carriers for the internal space heating and cooling due to heat transfer from the wall. In Iran, by allocating subsidies to the energy sector, tariffs for energy carriers are sensibly lower than global prices. In order to determine the insulation optimal thickness, energy carrier tariffs were considered variable according to consumption. Electricity and gas costs were divided into 4 ascending tariffs for low, moderate, high, and very high consumption cases. In addition, the case of energy carriers without subsidies was also examined the 5 . The outer wall consists of a typical hollow with 20cm thickness, insulated with an expanded polystyrene layer, placed the outside. Heat load due to heat transfer from the external wall was calculated by using EnergyPlus simulation software in different geographical directions and different thermal insulation thicknesses in Tehran climate. The optimum insulation thickness was determined based on the total cost over the lifetime of 30 years. According to the results, in the first tariff, which refers to low-cost subscribers, the use of thermal insulation in some geographic directions does not allow the payback period over a lifetime. In other directions, economic savings are low and . For higher tariffs, the optimum insulation thickness increases. In the 2 5 , the thermal insulation thickness from 6 to 18 cm. Also, the calculated payback periods of these configurations are between 6 and 28 years.
