Numerical Investigation on the Effect of Flow Parameters in CO2 Capturing Using Aqueous MEA Absorbent in HFMC Systems

Nowadays, CO2 as the product of fossil fuel combustions, is polluting the air and the human environment, and it causes global warming. To reduce the negative effect of CO2 presence, it should be removed from the air by capturing methods. Hollow fiber membrane contactor (HFMC) system is one of the most efficient method for CO2 capturing than the other feasible capturing methods. In the present paper an HFMC absorbing system has been simulated using COMSOL Multiphysics software and the effect of flow rates of gas and liquid on the amount of CO2 removal has been studied. Aqueous solution of Mono-ethanolamine (MEA) is entered as the absorbent liquid in the tubes, and CO2 is removed from the shell side by the diffusion phenomena by participating in the chemical reaction with MEA. The results show that the higher liquid flow rate the higher %CO2 removal from the inserted gas. Against this result, the percentage of CO2 removal decreases with increasing the gas flow rate as expected. Higher gas flow rate leads the gas velocity to higher values and less possibility of absorbing by the diffusion method. The rate of the CO2 removal variation with liquid flow rate is higher than the CO2 removal variation whit the gas flow rate.

Novel Photonic Crystal Based Polycrystalline CdTe/Silicon Solar Cells

In this paper, a novel photonic crystal (PhC) polycrystalline CdTe/Silicon solar cells are theoretically explained that increase their short circuit current density and conversion efficiency. The proposed structure consist of a polycrystalline CdTe/Silicon solar cell that a photonic crystal is formed in the upper cell. The optical confinement is achieved by means of photonic crystal that can adjust the propagation and distribution of photons in solar cells. For validation of modeling, the electrical properties of the experimentally-fabricated based CdS/CdTe solar cell is modeled and compared that there is good agreement between the modeling results and experimental results from the litterature. The results of this study showed that the solar cell efficiency is increased by about 25% compared to the reference cell by using photonic crystal. The open circuit voltage, short circuit current density, fill factor and conversion efficiency of proposed solar cell structure are 1.01 V, 40.7 mA/cm2, 0.95 and 27% under global AM 1.5 conditions, respectively. Furthermore, the influence of carrier lifetime variation in the absorber layer of proposed solar cell on the electrical characteristics was theoretically considered and investigated.

An Intelligent Fuzzy Logic Based Traffic Controller

Increasing road congestion, travel time, number of accidents, carbon dioxide emissions, and fuel consumption are some of the consequences of growth in the vehicle population. Therefore, intelligent traffic controllers are required to solve road traffic congestion problems. The results of prevalent methods, including preset cycle time controller and vehicle-actuated controller, indicated that they do not effectively perform at traffic peak moments. Therefore, due to the deficiency of common methods, fuzzy logic based traffic signal controllers have attracted a lot of attention among researchers. In this article, a fuzzy logic based algorithm for 4-way intersections is proposed and it consists of two main stages for sorting the phase and determining the green light duration. The proposed system is simulated in the MATLAB programming environment and the performance of the designed controller and a conventional controller is compared for some of the presumed conditions. The results of applying the proposed system indicate that this algorithm has a better performance in different traffic conditions in contrast to a preset cycle time controller and it can reduce the number of vehicles behind traffic lights at intersections and the waiting time of passengers.

Dietary Risk Reduction Projects in Industrial Foods in Iran

Non-communicable diseases (NCD) are the major cause of death worldwide. High intake of salt, sugar and fat are known as main risk factors for NCD. To address the issue some projects have been implemented in the country. This study aimed to seek for the initiatives targeting salt, sugar, and fat reduction in industrial foods and the status of implementation of food labeling. Meanwhile, we searched for studies which evaluated the above mentioned projects. We conducted an extensive review in domestic sources namely reports of national plans, protocols, dissertations, and progress reports of ongoing and terminated projects as well as rules and standards of Iran Food and Drug Administration (IFDA) and Institute of Standards and Industrial Research of Iran (ISIRI). There were several main projects in the country regarding reduction of dietary risk factors in industrial foods. Traffic light food labeling scheme and restrictions on imports of palm oil or food containing it, with support from food producers and revision of food standards were main interventions which were implemented by IFDA and ISIRI, respectively. In another project implemented by National Nutrition & Food Technology Research Institute (NNFTRI) the previously mentioned projects were evaluated. Results of other related projects are presented, as well. Some important steps have taken to reduce the rate of NCDs in the country. However, to achieve the goal of 25% reduction in NCDs by 2025, having a Surveillance, Monitoring and Evaluation (SME) plan is highly suggested to supports policymakers to take decision timely and correctly towards the enhancement of the effectiveness of the program.

Wastewater Treatment using Magnetic Nanoparticles and Nanocomposites

The application of magnetic nano-photocatalysts in clean water technologies, has been widely studied due to their improved chemical and physical properties. Due to the incorporation of magnetic materials into the nano-photocatalysts, the separation of the resultant nanocomposite can be facilitated via an applied external magnetic field, leading to more economic and also more ecologically friendly water refinement procedure. This paper presents a short review of magnetic nanomaterials in the purification of contaminated water/wastewater.