This study demonstrates the capability of the Weather Research and Forecasting (WRF) model with f... more This study demonstrates the capability of the Weather Research and Forecasting (WRF) model with fourdimensional data assimilation (WRF-FDDA) to produce a high-resolution climatography of seasonal precipitation over Israel and the surrounding areas. The system was used to dynamically downscale global Climate Forecast System (CFS) reanalysis with continuous assimilation of conventional and unconventional observations. Precipitation seasons (December-January-February) in 7 years, including two extreme dry and wet seasons observed in the past decades, were generated at 2-km spatial resolution. Verification against rain-gauge observations shows that the WRF-FDDA system effectively reproduces the spatial and inter-annual variability, as well as the timing, intensity, and length of wet and dry spells. The best agreement between model and observations was obtained at areas dominated by complex terrain, illustrating the benefit of the high-resolution lower boundary forcing in the dynamical downscaling process. In contrast, some biases were observed over coastal-flat terrain. The model was able to reproduce some of the extreme events, but exhibited limitations in the case of rare events. This specific discrepancy between the model and observations suggests that further fine tuning and different model configurations may be needed to correctly simulate extreme events. The use of an objective weatherregimes verification procedure reveals the skill of the climatography for different types of extra-tropical cyclones: while biases are larger at coastal-flat areas under shallow-cyclonic conditions, deep-cyclonic conditions lead to more significant biases in complex terrain regions. The weather-regimes dependent information may be used for further calibration of the downscaled precipitation.
Pulsating heat pipes (PHPs) are one of the new devices used for cooling in several applications s... more Pulsating heat pipes (PHPs) are one of the new devices used for cooling in several applications such as electronic and aerospace systems. Their low cost, effectiveness at various conditions, being equipped for passive energy conversion, and well distribution of temperature compared to conventional heat pipes are among the reasons of their popularity. To investigate the effect of surface tension of the working fluid on the behavior of PHPs, a copper heat pipe is fabricated with inner and outer diameters of 2 mm and 4 mm, respectively. Five different concentrations of cetrimonium bromide (C-Tab) surfactant are dissolved in water and are tested with a filling ratio of 50% (± 1%). A piece of glass is placed in the adiabatic section to make the flow visualizations possible. Thermal resistance and flow visualization results are compared. Visualization of the flow shows that by increasing the surfactant concentration, annular and semi-annular regimes can be observed at lower powers. It is also detected that by increasing the surfactant concentration, thermal resistance will decrease, while the maximum heat flux is reduced. This can be explained by thinner film thickness in the evaporator. The lowest thermal resistance was detected to be 0.44 K/W for the 0.25 g L-1 C-Tab concentration at 25 W heat input power which shows a significant improve of 77.5% compared to pure water at the same power.
The low level jet (LLJ) east of the Andes in South America plays a key role in the transport of h... more The low level jet (LLJ) east of the Andes in South America plays a key role in the transport of heat and water vapour from tropical to subtropical latitudes. It also plays a major role in the regional transport of pollutants and biological matter. This study examines the main spatial variability modes of the LLJ whose exit area reaches the La Plata Basin with no precipitation associated (which would remove aerosols)-Chaco Jet 1 (CJ1). The events were identified by applying the modified Bonner's criteria on the 850 and 700 hPa wind fields of the period 2001-2005 from GDAS (NCEP). With the help of an hybrid approach to Principal Component Analysis T-mode applied on the JRA-25 Reanalysis from the Japan Meteorological Agency, the main spatial patterns were identified during CJ1 episodes. Selected variables are geopotential height, specific humidity, equivalent potential temperature and the zonal and meridional wind components at 850 hPa. The first two PC components explained 35.64% of the variance. The significant fields show the entrance of the CJ1 to high (first PC) and middle (second PC) latitudes. The first component, with an explained variance of 21.1%, identifies episodes of moisture transport into high latitudes, and an intense flow north of 40 ∘ S. To the south, the most noticeable features for this component are moister conditions and weaker winds over Patagonia. The second component describes the situations where the flow turns towards the Atlantic Ocean at mid-latitudes, causing moisture to peak over the province of Buenos Aires and the north of Patagonia; with a stronger and more zonally oriented flow at high latitudes. The present analysis contributes to better understand the atmospheric circulation associated with CJ1 episodes and its implications on the regional transport of heat, moisture, pollutants and biological matter into La Plata Basin.
This experimental study is aimed at evaluation of the performance of secondary WAG injection in c... more This experimental study is aimed at evaluation of the performance of secondary WAG injection in carbonate cores at different pressures. To do so, a comprehensive series of high-pressure high-temperature (HPHT) core flooding tests are conducted. The fluid system includes reservoir dead and live crude oil, CO2, and synthetic brine while the chosen porous media consists of a number of fractured
The special geographical situation of Isfahan and its location in a depression as well as gatheri... more The special geographical situation of Isfahan and its location in a depression as well as gathering pollutants in the air has turned Isfahan to one of the most polluted cities in Iran. In winter, Isfahan has the most pollutants in the air. In summer and autumn, it has a high level of pollutants. But in spring, the city has healthy air. The synoptic study of the air indicates that there is a high pressure center in Isfahan which is the result of the strengthening and spread of Siberia high pressure center and the spread of its system over Iran. There is also a high center in the middle layer of atmosphere. This result is inversion and air stability. There is a sharp rise in the pollutants of the air in Isfahan at the time of the spread of Siberia high pressure center over Iran especially in the central areas. This results in serious harms to the citizen's health. In this research by studying the air synoptic condition in 2004 and 2005 and also the amount of pollutants in Isfahan at this time, we have tried to identify the role and effect of Siberia high pressure on urban pollution in Isfahan. By predicting synoptic spread of this high pressure center on Iran, we have tried to give the necessary information to city officials to carry out practical strategies in order to fight the destructive effects of this phenomenon before the air pollution.
The reactions affected by parameters climatically have a serious influence on national and intern... more The reactions affected by parameters climatically have a serious influence on national and international securities. The present study aims at evaluating the influence of parameters climatically on performance of wheat produced by dry farming in southeastern part of Caspian Sea. After data homogeneity test, reactions of parameters climatically on performance of the wheat were studied via correlation, one-variable regression model, and multi-variable stepwise regression. The results had shown that, the maximum weather temperature in May had the most effects on performance of dry farming wheat. Although the parameters did not show the significant trend, but the fluctuations in dry farming wheat, had shown the most relations and correlations which had negative trend, in a way that, the increase of maximum temperature in ratio with present temperature will result in decrease of the wheat performance in Golestan province. The result of modeling by multivariate regressions had shown very different results in different Townships which are not unexpected by regard of relief conditions and different climates in province. The witnesses showing that, in Townships of Bandargaz, Gorgan and Aliabad, none of the parameters were in the model which proves that there is another parameter that increases the performance of wheat and it may be seed type, Genetic changes and seeds resistance or poison and fertilizer types etc. Ramian Township has the positive role of rainfall in January means that, the performance of the dry farming wheat is increased by increase of rainfall and also it is reverse. Azadshahr Township has 5 parameters and Townships of AqQalla, Bandar Torkman and Minoudasht have 4 parameters in model which showed the most impressibility. This will make the prediction difficult but degrade of model's temperatures will decrease the mistakes. In created models for the three mentioned Townships, temperature in February month, sighted as an effective parameter.
Existence of natural symbol like mountains, rivers has valuable for each city. Besides these symb... more Existence of natural symbol like mountains, rivers has valuable for each city. Besides these symbols that are considered to be a factor in attracting tourists can acted likes as valuable symbol urban and There by increase the quality of urban environment. So the use of different methods for better and more illustrative presenting these symbols can help us reach the goal. In this study, the technique of projection mapping is investigated as an effective approach to the development of tourism in one the unique symbols of Esfahan (Atashgah mountain). The purpose of this study is "practical" and the method is "descriptive-analytic". Which was done by investigating the document and the library resources and also the websites. The results indicate that besides the attractiveness of projection functions on Atashgah mountains; it can be used for introducing, the city, history, literature, myth and not ables and also creating an entertainment event for people. The countries which are using this technique in introducing tourism potential provided a privileged position for themselves in terms of sustainable tourism.
This study demonstrates the capability of the Weather Research and Forecasting (WRF) model with f... more This study demonstrates the capability of the Weather Research and Forecasting (WRF) model with fourdimensional data assimilation (WRF-FDDA) to produce a high-resolution climatography of seasonal precipitation over Israel and the surrounding areas. The system was used to dynamically downscale global Climate Forecast System (CFS) reanalysis with continuous assimilation of conventional and unconventional observations. Precipitation seasons (December-January-February) in 7 years, including two extreme dry and wet seasons observed in the past decades, were generated at 2-km spatial resolution. Verification against rain-gauge observations shows that the WRF-FDDA system effectively reproduces the spatial and inter-annual variability, as well as the timing, intensity, and length of wet and dry spells. The best agreement between model and observations was obtained at areas dominated by complex terrain, illustrating the benefit of the high-resolution lower boundary forcing in the dynamical downscaling process. In contrast, some biases were observed over coastal-flat terrain. The model was able to reproduce some of the extreme events, but exhibited limitations in the case of rare events. This specific discrepancy between the model and observations suggests that further fine tuning and different model configurations may be needed to correctly simulate extreme events. The use of an objective weatherregimes verification procedure reveals the skill of the climatography for different types of extra-tropical cyclones: while biases are larger at coastal-flat areas under shallow-cyclonic conditions, deep-cyclonic conditions lead to more significant biases in complex terrain regions. The weather-regimes dependent information may be used for further calibration of the downscaled precipitation.
Pulsating heat pipes (PHPs) are one of the new devices used for cooling in several applications s... more Pulsating heat pipes (PHPs) are one of the new devices used for cooling in several applications such as electronic and aerospace systems. Their low cost, effectiveness at various conditions, being equipped for passive energy conversion, and well distribution of temperature compared to conventional heat pipes are among the reasons of their popularity. To investigate the effect of surface tension of the working fluid on the behavior of PHPs, a copper heat pipe is fabricated with inner and outer diameters of 2 mm and 4 mm, respectively. Five different concentrations of cetrimonium bromide (C-Tab) surfactant are dissolved in water and are tested with a filling ratio of 50% (± 1%). A piece of glass is placed in the adiabatic section to make the flow visualizations possible. Thermal resistance and flow visualization results are compared. Visualization of the flow shows that by increasing the surfactant concentration, annular and semi-annular regimes can be observed at lower powers. It is also detected that by increasing the surfactant concentration, thermal resistance will decrease, while the maximum heat flux is reduced. This can be explained by thinner film thickness in the evaporator. The lowest thermal resistance was detected to be 0.44 K/W for the 0.25 g L-1 C-Tab concentration at 25 W heat input power which shows a significant improve of 77.5% compared to pure water at the same power.
The low level jet (LLJ) east of the Andes in South America plays a key role in the transport of h... more The low level jet (LLJ) east of the Andes in South America plays a key role in the transport of heat and water vapour from tropical to subtropical latitudes. It also plays a major role in the regional transport of pollutants and biological matter. This study examines the main spatial variability modes of the LLJ whose exit area reaches the La Plata Basin with no precipitation associated (which would remove aerosols)-Chaco Jet 1 (CJ1). The events were identified by applying the modified Bonner's criteria on the 850 and 700 hPa wind fields of the period 2001-2005 from GDAS (NCEP). With the help of an hybrid approach to Principal Component Analysis T-mode applied on the JRA-25 Reanalysis from the Japan Meteorological Agency, the main spatial patterns were identified during CJ1 episodes. Selected variables are geopotential height, specific humidity, equivalent potential temperature and the zonal and meridional wind components at 850 hPa. The first two PC components explained 35.64% of the variance. The significant fields show the entrance of the CJ1 to high (first PC) and middle (second PC) latitudes. The first component, with an explained variance of 21.1%, identifies episodes of moisture transport into high latitudes, and an intense flow north of 40 ∘ S. To the south, the most noticeable features for this component are moister conditions and weaker winds over Patagonia. The second component describes the situations where the flow turns towards the Atlantic Ocean at mid-latitudes, causing moisture to peak over the province of Buenos Aires and the north of Patagonia; with a stronger and more zonally oriented flow at high latitudes. The present analysis contributes to better understand the atmospheric circulation associated with CJ1 episodes and its implications on the regional transport of heat, moisture, pollutants and biological matter into La Plata Basin.
This experimental study is aimed at evaluation of the performance of secondary WAG injection in c... more This experimental study is aimed at evaluation of the performance of secondary WAG injection in carbonate cores at different pressures. To do so, a comprehensive series of high-pressure high-temperature (HPHT) core flooding tests are conducted. The fluid system includes reservoir dead and live crude oil, CO2, and synthetic brine while the chosen porous media consists of a number of fractured
The special geographical situation of Isfahan and its location in a depression as well as gatheri... more The special geographical situation of Isfahan and its location in a depression as well as gathering pollutants in the air has turned Isfahan to one of the most polluted cities in Iran. In winter, Isfahan has the most pollutants in the air. In summer and autumn, it has a high level of pollutants. But in spring, the city has healthy air. The synoptic study of the air indicates that there is a high pressure center in Isfahan which is the result of the strengthening and spread of Siberia high pressure center and the spread of its system over Iran. There is also a high center in the middle layer of atmosphere. This result is inversion and air stability. There is a sharp rise in the pollutants of the air in Isfahan at the time of the spread of Siberia high pressure center over Iran especially in the central areas. This results in serious harms to the citizen's health. In this research by studying the air synoptic condition in 2004 and 2005 and also the amount of pollutants in Isfahan at this time, we have tried to identify the role and effect of Siberia high pressure on urban pollution in Isfahan. By predicting synoptic spread of this high pressure center on Iran, we have tried to give the necessary information to city officials to carry out practical strategies in order to fight the destructive effects of this phenomenon before the air pollution.
The reactions affected by parameters climatically have a serious influence on national and intern... more The reactions affected by parameters climatically have a serious influence on national and international securities. The present study aims at evaluating the influence of parameters climatically on performance of wheat produced by dry farming in southeastern part of Caspian Sea. After data homogeneity test, reactions of parameters climatically on performance of the wheat were studied via correlation, one-variable regression model, and multi-variable stepwise regression. The results had shown that, the maximum weather temperature in May had the most effects on performance of dry farming wheat. Although the parameters did not show the significant trend, but the fluctuations in dry farming wheat, had shown the most relations and correlations which had negative trend, in a way that, the increase of maximum temperature in ratio with present temperature will result in decrease of the wheat performance in Golestan province. The result of modeling by multivariate regressions had shown very different results in different Townships which are not unexpected by regard of relief conditions and different climates in province. The witnesses showing that, in Townships of Bandargaz, Gorgan and Aliabad, none of the parameters were in the model which proves that there is another parameter that increases the performance of wheat and it may be seed type, Genetic changes and seeds resistance or poison and fertilizer types etc. Ramian Township has the positive role of rainfall in January means that, the performance of the dry farming wheat is increased by increase of rainfall and also it is reverse. Azadshahr Township has 5 parameters and Townships of AqQalla, Bandar Torkman and Minoudasht have 4 parameters in model which showed the most impressibility. This will make the prediction difficult but degrade of model's temperatures will decrease the mistakes. In created models for the three mentioned Townships, temperature in February month, sighted as an effective parameter.
Existence of natural symbol like mountains, rivers has valuable for each city. Besides these symb... more Existence of natural symbol like mountains, rivers has valuable for each city. Besides these symbols that are considered to be a factor in attracting tourists can acted likes as valuable symbol urban and There by increase the quality of urban environment. So the use of different methods for better and more illustrative presenting these symbols can help us reach the goal. In this study, the technique of projection mapping is investigated as an effective approach to the development of tourism in one the unique symbols of Esfahan (Atashgah mountain). The purpose of this study is "practical" and the method is "descriptive-analytic". Which was done by investigating the document and the library resources and also the websites. The results indicate that besides the attractiveness of projection functions on Atashgah mountains; it can be used for introducing, the city, history, literature, myth and not ables and also creating an entertainment event for people. The countries which are using this technique in introducing tourism potential provided a privileged position for themselves in terms of sustainable tourism.
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