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Showing 3 results for Rostamian
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.

Effect of pull-winding process in thermoplastic composite rod on the impregnation of glass fiber
Rohollah Rostamian, Mohammad Golzar,
Volume 17, Issue 3 (5-2017)
Abstract
In the pultrusion process, continuous fibers reinforcement in roving forms are drawn through a pultrusion die. Therefore, the fibers reinforcement in the final product are generally oriented in the longitudinal axis. In this research, for manufacturing of composite rods, on the basis of previous studies and researches, the E-glass fiber-polyethylene prepregs were produced firstly. Then due to the Design of Experiments (DOE), the pultruded rods with unidirectional and helically-wound layers were produced by using the prepregs. In this study, mechanism of the pull-winding process is created as a secondary process during the main process to improve the mechanical and physical properties in the other directions. One of the most important issues in the thermoplastics pultrusions is the fibers impregnation quality with the polymer base. The fiber volume fractions of the productions are found by the burn tests. The density of the specimens is found by the liquid displacement method. The microscopic images were taken from cross-section of the pultruded rods to investigate the fiber impregnation and the void distribution. Due to the surveys conducted, the fiber volume fractions in the pultruded rods was increased, using the pull-winding technique, and also the void content of these rods was decreased.
Characterization and Sodium Sorption Capacity of Biochar and Activated Carbon Prepared from Rice Husk

Volume 17, Issue 4 (7-2015)
Abstract
Biochar and activated carbon, as carbon-rich porous materials, have wide environmental applications. In the present research, rice husk (RH) was used for preparation of biochar at 400, 600, and 800 °C under simple pyrolysis, physically-activated carbon with water steam, chemically-activated carbon with potassium hydroxide (KOH), and physiochemically-activated carbon with KOH and steam. Physical and chemical properties of biochar and activated carbons were characterized using nitrogen adsorption–desorption isotherm, Fourier transform, infra-red analysis, and Boehm method. The results showed that carbonization temperature and activation agents had significant effects on the characteristics of the samples. Activated carbon produced by KOH activation had the highest surface area (2201 m2 g-1) and total pore volume (0.96 cm3 g-1). High concentration of sodium (Na) is an important limiting factor to reuse poor quality water resources in arid and semiarid regions. The sorption capacity of biochars and activated carbons was investigated by performing batch sorption experiments using Na as adsorbate. Na sorption was increased with increasing surface area and pore volume. The highest Na sorption capacity of 134.2 mg g-1 was achieved by the KOH activated carbon, which has the highest surface area and pore volume. The kinetic data were well-fitted to pseudo-first order and intra-particle diffusion models.
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