علوم غیرزیستی دریا
Abbas Einali; Vahid Chegini
Abstract
Pozm bay Located in southern coast of Iran near Oman Sea, due to its relative calmness, low depth and being affected by the land substances is interesting to some aquatics species for reproduction and spending part of their growth period. In this research the seasonal variations of physical parameters ...
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Pozm bay Located in southern coast of Iran near Oman Sea, due to its relative calmness, low depth and being affected by the land substances is interesting to some aquatics species for reproduction and spending part of their growth period. In this research the seasonal variations of physical parameters trend of the Pozm pay was investigated during 9 periods since Oct 2011 till Aug 2012. The physical parameters of the sea water were measured by the CTD device in 17 stations from surface to seabed. These parameters are as follows: Temperature, Salinity, Density, Electrical conductivity, Sound velocity, Turbidity, and the Dissolved oxygen. According to the results of this research, the variations of the water temperature are following the air temperature and increase as the air temperature arises in hot seasons. Although due to the low depth of Pozm bay the formation of thermocline layer and water stratification are so low, weak stratification is formed in water column during hot months of the year. The entering flow of Oman Sea water into the Persian gulf, which is less salty comparing to that of Persian gulf, is maximized during late spring and minimized in winter and affects the salinity of Pozm bay water such that its rate is more during mild months than hot months. The variation of the density is influenced by water temperature and the salinity has no effect on them. The summer monsoon has a significant effect on the physical parameters of Pozm bay's water.
مهندسی دریا
Seyed Amin Asghari Pari; Seyed Malek Mohagheghiyan
Abstract
Turbidity currents are one of the most fundamental factors that transferring sediment near the dam. In this article, the effect of roughness, pattern, height and the shape of roughness in the floor on controlling turbidity current are studied using finite elements numerical method by ANSYS-CFX. For solving ...
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Turbidity currents are one of the most fundamental factors that transferring sediment near the dam. In this article, the effect of roughness, pattern, height and the shape of roughness in the floor on controlling turbidity current are studied using finite elements numerical method by ANSYS-CFX. For solving turbulence equations are used K-e method. After calibrating of model has done, at the first, simulated flow without roughness and then three shape of roughness pyramid-shaped, round edge cylindrical and cubic with two alternative zigzag and consecutive, with 5 different height and for subcritical and supercritical flow regime are modeled. The results indicated that with the increase in height of the roughness and cross flow and with zigzag arrangement, reduced the turbidity current discharge. Also the effect of roughness on controlling subcritical turbidity current are more than supercritical flow.
مهندسی دریا
khosro fazelpoor
Abstract
In order to provide SST images, the sensor MODIS installed on Aqua Satellite EOS-1 was used. Applying lighting assessment out of images from Modis 21-Level 1B Calibrated Radiances -1km in Persian Gulf and the Bushehr sea station (Bouyeh) from global algorithm specified for above sensor was used to estimate ...
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In order to provide SST images, the sensor MODIS installed on Aqua Satellite EOS-1 was used. Applying lighting assessment out of images from Modis 21-Level 1B Calibrated Radiances -1km in Persian Gulf and the Bushehr sea station (Bouyeh) from global algorithm specified for above sensor was used to estimate the sea surface temperature. With function of Matlab software to extract data of satellite images, and GIS software to convert the matris obtained, the maps of sea surface temperature were used. Forty eight images taken in 2008, 2009, 2012, and 2013 were selected. Their correlation coefficient eventually was 0.75, 0.86, and 0.75 respectively. Likewise the special coefficient obtained as 0.86, 0.90, 0.94 and 0.86 respectively. Finally, taking the 31 band temperature into consideration for the years 2008, 2009, 2012 and temperature differences of bands 31 and 32 and the sensor angle as independent factors were used at Bouyeh temperature as an affiliated factor calibrated by SPSS software for global algorithm of Persian Gulf. In order to check the correctness the algorithm suggested, the sea surface temperature was re-examined with satellite images of the year 2013; the correlation coefficient 0.96 and 0.94 were obtained. The searching has shown that the depth with current sea and latitude have effect on sea surface temperature, and temperature balance specially in north and central latitude have contrary relation with depth.