Showing 6 results for Zareie
Volume 1, Issue 2 (winter 2018)
Abstract
In general, temporary well plugging is essential for repairing of oil and gas wells due to their long life time. One of the newest methods used for this purpose is gel polymer plugging. The strength of the gel in the well conditions is one of the most important challenges in the application of gel polymer in the temporary well plugging in work over operation. In this study, silica nanoparticles were used to improve the strength of polymer hydrogels. The bottle and rheological tests were used to determine the gel strength in desired well conditions (high temperature and high salinity). Also, the gel strength properties and swelling behavior were studied in various conditions such as distilled water, formation water, tap water and oil. It was observed that the strength of the gel increased from 520Pa to about 36kPa (5000% increase) by adding nanoparticles. Also, the gel swelling in the aqueous solution has been significantly reduced. Based on the results obtained in this study, a polymer gel containing 9 wt.% of silica nanoparticles with structural strength and thermal stability at 90 °C was introduced for field studies.
Volume 9, Issue 1 (10-2019)
Abstract
Risk and failure in the supply chain can have a significant and negative effect on the short-term and long-term performance of the participants in the chain. Therefore, this research has an innovative look for a mathematical model for analyzing the interactive risks of the supply chain system using Bayesian belief networks. The study is descriptive in terms of purpose and has descriptive nature. The research community is classified into the two categories of academic experts and operational experts. In this research, information on the drug supply chain of the Imam Reza Hospital of Mashhad was obtained and analyzed using the bayesian belief network modeling process. The findings of this study show that Bayesian belief networks are much better than traditional risk analysis methods, because it can analyze basic risk analysis, including risk ranking and scenario analysis, and other essentials. BBN can also display different uncertainties in the language of probabilities with an appropriate visual form and provide more comprehensive view of the supply chain conditions and its risks
Volume 12, Issue 2 (2-2021)
Abstract
Abstract
Isfahan is one of the most prominent cities in Iran's central plateau for centuries and during the rule of Al-Buyih, Seljuqyan and Safavid, Iran was the capital and center of Iran. Isfahan's special position in the Center of Iran and its connection with other parts of the interior and exits and the flow of the Zayandeh-e Rood River as the most important natural disorder made it possible for Isfahan, Stay up to date with the most ancient days of human habitation and the attention of different governments. The appropriate environmental and natural, historical, communicational, military, commercial and economical substrates have been the factors of the evolution and dynamics of the city of Isfahan from the past. King Abbas tried to compete with the Ottoman government in a military, economic, religious and especially architecture and urban environment in the development of Isfahan and bestowed it. Growth and development of Isfahan city at the time continued the successors of Shah Abbas-Kabir until Shah Sultan Hussein's time. Considering that most scholars and writers of Shah Sultan Hussein have been considered as the main cause of the collapse of the Safavid dynasty. Consequently, in connection with the architecture and urbanization of Isfahan, his covenant has not been studied comprehensively. The purpose of the present paper is "The study of the development of urban life of Isfahan during the era of Shah Sultan Hussein Safavi and the effects of the endowment tradition on it." In this way, we try to answer these questions; what has progressed in urban planning and architecture during Shah Sultan Hussein Safavid? How did the devotees influence urban construction during the era of Shah Sultan Hussein Safavi? As a result of this study, which was carried out using library and field method, which was the era of Shah Sultan Hussein in the field of architecture and urban development of the dynamic era, and during this period, the city of Isfahan, as the era of King Shah Abbas grew and even the iconic buildings such as the Chaharbagh School were created that equal the best examples of the King Shah Abbas age.
Mohammad Akbari, Akbar Zareie,
Volume 16, Issue 6 (8-2016)
Abstract
Nano-fluids are prepared by suspending the ultrafine nanoscale particles in the base fluid and can be substantially enhanced the heat transfer rate compared to pure fluids. Because of great importance of dynamic viscosity applications in related applications of nanofluids in heat transfer and energy systems, experimental investigation of the effects of volume concentration and temperature on dynamic viscosity of MgO – MWCNTs/EG-water hybrid nanofluid has been presented in this study. The nanofluids were prepared with solid volume fractions of 0.025%, 0.05%, 0.1%, 0.2%, 0.4%, 0.6% and 0.8% and experiments were performed in the temperature range of 25 to 60⁰C. In addition, by investigating the rheological behavior of nanofluid against shear rate, the Newtonian behavior was observed. Regarding the weakness of the previous correlations for predicting the dynamic viscosity of this nanofluid and according to the experimental data, a new equation was proposed. The results showed that by increasing the solid volume fraction, the dynamic viscosity increased. This increase is more tangible at lower temperatures compared with higher temperatures. Moreover, at the temperature of 60⁰C, the solid volume fraction has no great effect on the dynamic viscosity of the nanofluid which this issue can be considered as an important achievement in the industrial and engineering applications.
Hamid Reza Talesh Bahrami, Saeed Zareie, Hamid Saffari,
Volume 17, Issue 3 (5-2017)
Abstract
In In this paper nanofluids condensation heat transfer on an inclined flat plate is investigated. To do this, thermal resistances of single droplets are calculated and the total heat flux is evaluated using population balanced theory. The nanofluids include alumina, titanium dioxide and silver as nanoparticles and water as a base fluid. Effects of different surface inclinations, nanofluids types, and nanoparticles concentrations are investigated on the heat transfer. Nanofluids properties consisting of thermal conductivity, density, dynamic viscosity, and latent heat are extracted from literature and introduced into the equations. The results are compared with some experimental data in the same conditions. The Nusselt theory is used to compare the heat transfer rate of filmwise condensation with dropwise condensation. Inspecting the results shows that the heat transfer coefficient of a vertical plate is maximum, and decreases with decreasing in inclination due to lower washing rate of small droplets by sliding droplets. The results also show that the heat transfer coefficients of various nanofluids are different but they are constant all over the surface. As well as, addition of nanoparticles to the base fluid increases heat transfer rate. It can be seen that water-silver nanofluid has the maximum heat transfer rate among three beforehand mentioned nanofluids in the same conditions and the heat transfer rate increases with increase in volume fraction of nanoparticle for a specific nanofluid.
Volume 22, Issue 5 (12-2022)
Abstract
In recent years the use of nano materials in engineering projects has significantly increased. In fact, the impact of nano materials as a component in composite materials is one of the new horizons in engineering science. On the other hand, existence of heavy metal contaminated soils is one of the common problems in geo-environmental projects all around the world. In the process of retention of heavy metals by clayey soils, the pH of soil solution plays a significant role. In fact, an increase in pH of soil pore fluid causes a noticeable increase in contaminant retention. On the other hand, the use of additives in soil can increase the contaminant retention as well. In comparison with other additives such as cement, polymers do not require a long curing conditions. In addition, they have a positive impact on permeability of compacted soil, in which their presence decrease the soil permeability. In spite of several researches on the interaction process of clay minerals and polymer, there are very limited researches on the interaction process of polymer-clay minerals-heavy metal contaminant. Therefore, the main objective of this paper is to investigate the role of polyacrylamide polymer in retention of heavy metals in bentonite.
To achieve the above mentioned objective, at the first step, the buffering capacity of polymer treated bentonite samples were measured. In this series of experiments, different concentrations of nitric acid from 0.002 to 0.02 molar were prepared. Then, 4 grams of bentonite and bentonite treated with different concentrations of polymer were poured in centrifuged tubes. Then, 40 cc of nitric acid were added to each centrifuge tube. After equilibrium period, the pH of soil suspension was measured and reported. In the second step of this research, two different series of experiments were performed. In the first series of experiments of this research, bentonite treated by polymer were exposed to different concentrations of heavy metal contaminants. In the second series of experiments, contaminated bentonite samples were treated by different percentages of polymer. The contaminant retention of these samples was investigated by performance of sets of batch equilibrium experiments. The achieved results indicate that the polymer treated bentonite sample (with 3% polymer), after exposure to 200 cmol/kg-soil has shown 19% increase in contaminant retention in comparison to bentonite sample. However, the addition of 3% polymer to contaminated bentonite with 200 cmol/kg-soil lead nitrate has shown 72% increase in contaminant retention in comparison to contaminant retention of bentonite sample. Based on the achieved experimental results it is concluded that there are three phases in heavy metal contaminants in interaction process of bentonite-polymer-heavy metal. These phases include retention by double-layer of clay, the contaminant retention in micro pores of clay minerals which are solidified by polymer, and the contaminate retention capability of polymer. According to the achieved results, the solidification effect of polymer has more contribution to the contaminant retention than the polymer buffering capacity. This proves that post-solidification of contaminated bentonite is a practical method for efficient prevention of contaminant transport in clayey soils.
