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Showing 4 results for Etesami
A comprehensive review on the application of nanoparticles in the matrix of phase change materials to improve thermal properties for energy management and storage

Volume 7, Issue 4 (Winter 2023)
Abstract
Given the ever-increasing demand for energy and the limited nature of fossil fuel resources, improving energy efficiency and storage has become one of the most significant challenges facing humanity. Phase Change Materials (PCMs), substances capable of absorbing and releasing thermal energy at a constant temperature, have emerged as an innovative solution in the field of energy storage. With their high latent heat capacity, ability to maintain a stable temperature, and environmental friendliness, PCMs have great potential for applications in various industries. However, their low thermal conductivity, especially in organic PCMs, has hindered their widespread use. To address this challenge, researchers have been exploring various methods to enhance the thermal properties of PCMs. One of the most effective approaches involves incorporating high thermal conductivity nanoparticles into the PCM matrix. This research comprehensively reviews recent advancements in the preparation and applications of nanoparticle-enhanced phase change materials. It delves into various types of nanoparticles used, production methods for nanocomposites, the impact of nanoparticles on the thermal and mechanical properties of PCMs, the stabilization of nanocomposites with surfactants and surface modification, and also their potential applications in diverse industries. The results of this study indicate that the use of nanoparticles can significantly improve the thermal conductivity of PCMs, with carbon-based nanofillers showing the highest impact. Additionally, nanoparticles have led to a relative reduction in the phenomenon of supercooling in PCMs. Based on the results of numerous studies, nanoparticle-enhanced phase change materials hold great promise for improving the performance of energy storage systems, reducing energy consumption in various industries, and fostering the development of sustainable technologies. These nanocomposites can be employed in the construction, automotive, electronics, and textile industries to create more comfortable environments, enhance energy efficiency, and reduce greenhouse gas emissions. Continued research in this field is expected to lead to the development of even more efficient PCMs with a broader range of applications.

Radiation Characteristics of Plasma Triangular Antenna

Volume 11, Issue 3 (10-2011)
Abstract
This paper presents the results of a study on the radiation characteristics of a plasma triangular antenna in the VHF band (30-300MHz) applying the method of moment. Deriving the current distribution of the antenna, it shows the relationship between radiation characteristics of the plasma antenna and the plasma parameters. Both theoretical and numerical results indicate that if the plasma frequency is sufficiently higher than the operating frequency and the collision frequency is correspondingly low, the radiation treatment of the plasma antenna will be close to a metal one. Also the consequence of simulations reveals the proposed plasma antenna has better peak gain than the conventional plasma column on the operating band. The results of the current study are checked by using full wave HFSS simulator.    
Experimental analysis of pool boiling heat transfer of ferrofluid on surfaces deposited with nanofluid
Ali Abdollahi, Mohammad Reza Salimpour, Nasrin Etesami,
Volume 16, Issue 2 (4-2016)
Abstract
Boiling heat transfer is one of the most applicable heat transfer processes within the industry. In this paper, the pool boiling heat transfer of Fe3O4 /water nanofluid (ferrofluid) in atmospheric pressure has been analyzed, experimentally. The nanofluid in this study, has been synthesized in a single step and retains high stability. The replication and accuracy of the testing machine has been studied for deionized water for three times, indicating an appropriate concordance with the literature. Considering different volume concentrations of the nanofluid has revealed that boiling heat transfer in high concentrations decreases with an increase of concentration, while it rises with the increase of concentration in low concentrations. Hence, boiling heat transfer coefficient in 0.1% volume concentration nanofluid has been measured to be the optimum value which increases up to 43%. The roughness of boiling surface was varied with the deposition of nanoparticles in various conditions of nanofluid concentration, and heat flux. It is noteworthy that in the present research, the effects of surface roughness changes due to nanoparticles deposition and the impact of passing time on boiling process have been investigated, for the first time. Therefore, several experiments have been designed in order to study the change of nanoparticles deposition due to the change of nanofluid concentration and boiling surface heat flux. The results indicate that boiling heat transfer of deposited surfaces at low heat fluxes decreases; while it rises at high heat fluxes.
Effect of Mulching on Some Characteristics of Tomato (Lycopersicon esculentum Mill.) under Deficit Irrigation

Volume 21, Issue 4 (7-2019)
Abstract
The aim of the study was to evaluate the sole and interactive effect of drip irrigation regimes (50, 70, and 100% of Crop Water Requirement, CWR) and different mulches [No Mulch (NM); Mood Chip Mulch (WCM); Composted Wood Chip Mulch (CWCM), and Plastic Mulch (PM)] on some morphological and physiological traits of tomato, Water Use Efficiency (WUE), and soil properties (soil moisture and temperature) under field conditions. Results showed that yield and its components were significantly influenced by different levels of irrigation. Different mulches increased fruit yield by 12–46% over non-mulch conditions. The highest marketable yield (5.78 kg plant -1) and total yield (5.77 kg plant -1) were obtained by the plants under the highest water level (100% CWR) along with PM and WCM, respectively. The lowest percentage of cracked fruits and blossom-end rot fruits was observed in the plants under 100 and 70% CWR along with WCM. In addition, the highest WUE (18.27 kg m-3) was obtained with 70% water application under WCM. In general, the study revealed that drip irrigation with wood chip mulch had a significant role in increasing the yield of tomato and saving irrigation water under field conditions.
 
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