Chemical Engineering
M. Imani-Hassanloui; M. R. Maraki; Z. Taghimalek; H. Tagimalek
Abstract
Nowadays, vending is the most important pillar of a production set. The positive and significant points of the manufactured parts are attained by interviewing with the customer, sending a questionnaire to the customer, testing the market, investigating the quality and reliability of new products, probing ...
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Nowadays, vending is the most important pillar of a production set. The positive and significant points of the manufactured parts are attained by interviewing with the customer, sending a questionnaire to the customer, testing the market, investigating the quality and reliability of new products, probing the reports and product quality of competitors. Aimed at predicting the type of leadership in reverse engineering, based on “Voice of Customer” (VOC), between the Iran Khodro Company’s (IKC) managers (case study of Peugeot 405 brake pump shell), the present study was conducted. Using descriptive-correlation research method, about 90 managers were randomly selected in several categories according to gender, age and years of service, proportional to the size of each category. Three questionnaires of “Oregon and Kanowski Organizational Citizenship Behavior” (OKOCB), “Fry Spiritual Leadership” (FSL), and researcher-made “Charismatic Leadership” (CL) were utilized to collect the research data. To measure the reliability rate using Cronbach's alpha coefficient, this item was obtained for all three questionnaires of the OKOCB, FSL and CL behavior (α = 0.92, 0.81 and 0.85) respectively. Collecting the data, they were analyzed using multiple regression analysis and based on the research hypotheses. The results indicated that there is a positive and significant relationship between the dimensions of SL and organizational citizenship behavior, and also between the CL and the organizational citizenship behavior. The results of structural equation modeling also showed that SL with a path coefficient 0.7 is able to affect overall quality management (t ≥ 1.96, p≤ 0.05).
Renewable Energy
B. Khorram; I. Mirzaee; S. Jafarmadar
Abstract
The main purpose of this study is to evaluate the thermodynamic and economic performance of using a solar chimney and wind turbine to help generate electricity in a multigeneration system. The proposed system is designed to generate power, heating, cooling, hot water, and steam. Parametric studies were ...
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The main purpose of this study is to evaluate the thermodynamic and economic performance of using a solar chimney and wind turbine to help generate electricity in a multigeneration system. The proposed system is designed to generate power, heating, cooling, hot water, and steam. Parametric studies were conducted to evaluate the effects of various parameters such as Brayton cycle turbine inlet pressure, organic Rankine cycle turbine inlet temperature, solar radiation, wind speed, and absorption refrigeration cycle evaporator temperature on the system efficiency. The effects of these parameters on the energy, exergy, and economic efficiencies of the whole system were investigated. The results showed that the highest energy efficiency and total exergy of the multigeneration system were 22.12% and 11.4%, respectively. Also, the total power generation capacity of the studied system was calculated to be 2103 kW. The results also depicted that the highest rate of exergy destruction for the main components of the system is found in the parabolic dish solar collector. Increasing the turbine inlet pressure, the average wind velocity of the wind turbine and, evaporator temperature increasing of absorption refrigeration cycle has a positive effect on the efficiency of the proposed system.
A. Singh; K. K. Singh
Abstract
The problem of air pollution has ramifications for human health, the environment, and a variety of living sectors. Modern technology has resulted in air pollution and its damaging effects, while also driving the world to make every effort to overcome its negative repercussions. The origin, chemical composition, ...
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The problem of air pollution has ramifications for human health, the environment, and a variety of living sectors. Modern technology has resulted in air pollution and its damaging effects, while also driving the world to make every effort to overcome its negative repercussions. The origin, chemical composition, size, and mode of discharge inside or outdoor environments have all been proven to be air pollutants. Industrial, commercial, mobile, urban, regional, farm, and natural sources of indoor pollutants include cooking and combustion, particle matter rehabilitation, materials used for resources, temperature control, and consumer items, smoking, heating, and organic compounds. Indoor Pollutant Sources Air pollution has an impact on the body, including respiratory systems and heart disorders. Asthmatics, bronchiolitis, lung disease, cardiovascular problems, central nervous system malfunction, and skin conditions are the most common respiratory disorders, as are chronic obstructive pulmonary disease (COPD). The challenges posed by outdoor air pollution are public health risks such as cardiovascular disease, respiratory ailments, COPD, and world-class asymmetry. The impacts of human activities on air quality and climate change may be realized at several sizes, ranging from urban to regional to continental to global. Rapid population growth and increased energy consumption are the principal drivers of massive amounts of hazardous chemicals and greenhouse gases entering the atmosphere, with serious consequences for health and the environment.
Chemical Engineering
Y. Kiamehr; I. Naser; M. Rafizadeh; A. H. Mohammadi
Abstract
Removal of CO2 in natural gas refining has currently been the only membrane based process practiced on a large scale operation. Despite the predominance of polymeric membranes in the CO2/CH4 separation, the tradeoff limitation in between membrane selectivity and permeability hinders a good separation ...
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Removal of CO2 in natural gas refining has currently been the only membrane based process practiced on a large scale operation. Despite the predominance of polymeric membranes in the CO2/CH4 separation, the tradeoff limitation in between membrane selectivity and permeability hinders a good separation performance of these membranes. Mixed matrix membranes can offer dramatic improvement to overcome this shortcoming. In this study, polyetheresulfone mixed matrix membranes incorporated with small pore amine modified SAPO-34 were proposed for CO2 separation. SAPO-34 zeolite was used as inorganic fillers to enhance gas selectivity. The asymmetric membrane structure was prepared using the phase inversion method in order to improve permeance. SEM images and FTIR analysis were used to characterize the filler particles and the synthesized membranes. SEM images also indicated that, there were appropriate distribution particles in the polymer matrix.The effects of filler loading (0-10 wt%), feed temperature (303-343 K) and feed pressure (0.5-4 bar) on CO2/CH4 selectivity of the MMMs were investigated. The results indicated that addition of amine-functional SAPO-34 in the casting solution enhanced the membrane gas permeance and CO2/CH4 ideal selectivity. For the membrane with 10 wt% of amine loading, selectivity was 17% higher than the membrane without functionalizing with amine Increasing the temperature from 303 to 343 K reduced selectivity around 25-30.5 %.
Energy
F. O. Aweda; T. K. Samson
Abstract
This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from ...
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This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from 1985 to 2019 was analyzed using Mann-Kendal statistics on the trend of the rainfall series while the normality of rainfall series was determined using Kolmogorov- Smirnov test across six southwest stations of Nigeria. The results revealed the highest mean rainfall in Akure (198.9 mm) while the least rainfall in Ado-Ekiti (163.4 mm). The maximum rainfall was in Abeokuta (865.8 mm) with Iwo having the highest disparity in rainfall (SD=148.8 mm) compared with other stations. The skewness in Abeokuta (Skewness = 0.9 mm) was higher compared with Ado-Ekiti, Akure, Ibadan, Ikeja and Iwo with skewness values of 0.7 mm, 0.4 mm, 0.7 mm, 0.6 mm and 0.7 mm, respectively. The maximum air temperature was recorded in Iwo (301.7 K) and the minimum air temperature in Ado-Ekiti (293.3 K). The skewness obtained in Akure (-0.2) and Ikeja (-0.3) was less than zero indicating that air temperature decreased more than it increased in these areas while in other stations, Abeokuta (0.01), Ado-Ekiti (0.22), Ibadan (0.02) and Iwo (0.24), the skewness was greater than zero meaning that air temperature increased more than it decreased in these stations.
Chemical Engineering
A. Alipour; S. Zarrinabadi; A. Azimi; M. Mirzaei
Abstract
Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology ...
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Cellulose nanocomposites were synthesized and applied to the removal of Pb(II) from aqueous solution. The synthesized nanocomposite was characterized by FT-IR, XRD, SEM, TEM, and BET analyses. Removal experiments were carried out in laboratory scale and then evaluated by response surface methodology (RSM) with a Central-Composite Design. The effects of solution pH, contact tie, initial Pb(II) concentration, adsorbent dosage and temperature on the removal efficiency were evaluated. Analysis of variance (ANOVA) was employed to find which parameter has a significant effect on the removal efficiency. The best removal efficiency value was found to be at the initial solution pH of 6.5, temperature of 34°C, initial ion concentration of 100 mg/L and the adsorbent dosage of 0.74 g/L. At this condition, the removal efficiency of Pb(II) ions was 92.54%. The adsorption equilibrium data fitted well with Langmuir isotherm model and the adsorption process followed the pseudo-second-order and intra-particle diffusion kinetic model. Thermodynamic analysis suggests that the adsorption process is endothermic, with an increasing entropy and spontaneous in nature. Besides, the nanocomposite was reused in four successive adsorption–desorption cycles, revealing a good regeneration capacity of the adsorbent. The effects of coexist cation ions on the adsorption of Pb(II) under optimal condition was also investigated. All the results demonstrate that nanocomposite is a potential recyclable adsorbent for hazardous metal ions in wastewater system.
Environment
Z. Poormolaie; M. Mohammadi; M. Ghafoori; E. Khayyami
Abstract
The aim of this study was to determine the air quality index (AQI) and to investigate its relationship with meteorological parameters in Mashhad for 2014. In this study, moment concentrations of air pollutants in Mashhad for 2014 were prepared and the amount of AQI was calculated and air quality was ...
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The aim of this study was to determine the air quality index (AQI) and to investigate its relationship with meteorological parameters in Mashhad for 2014. In this study, moment concentrations of air pollutants in Mashhad for 2014 were prepared and the amount of AQI was calculated and air quality was determined. Then, data analysis was performed using Kruskal-Wallis and Mann-Whitney tests at a significant level of 5% in SPSSV.23 software. Finally, data related to meteorological parameters were prepared during 2014 and ARIMA time series model and R software (3.3.0) were used to investigate its relationship with air index pollutants in non-delayed and one day late modes. The results showed that air quality of Mashhad was in a very bad condition in terms of maintaining the health of community members, especially sensitive groups, as the concentration of pollutants in this city was higher than Iranian standard (100) in 245 days of the study period. The PM2.5 was the most important pollutant during the study. It was also found that among the climatic parameters, temperature and pressure have the greatest direct effect on the concentration of air pollutants. Moreover, results showed the immediate effect of temperature on the concentration of air pollutants, although other atmospheric elements are able to significantly affect the outcome over time and with a time delay (one day in this study). The results indicated that quality of model computation depends on changes in atmospheric parameters, so that a quantitative measurement for each pollutant can be achieved based on meteorological data.
Energy
N. Amani; A. Sabamehr; L. M. Palmero Iglesias
Abstract
The building sectors are recognized as one of the essential contributors of global warming and climate change because of their high energy use. The building sector is responsible for 40% of all energy usage and 40% of the CO2 emissions in the developed countries. Researchers in the world are working ...
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The building sectors are recognized as one of the essential contributors of global warming and climate change because of their high energy use. The building sector is responsible for 40% of all energy usage and 40% of the CO2 emissions in the developed countries. Researchers in the world are working on energy management and conservation using simulation software to develop strategies that lead to an overall reduction of energy consumption in the buildings. This review is considered a modeling and simulation approach with a specific focus on residential building. Modeling and simulation methods reviewed are presented categorically as per the strategic approach adopted by the researchers. Simulation results available for residential building energy are also introduced. This research has reviewed the capabilities and performances on Ecotect simulation and modeling, including daylighting, solar radiation, thermal analysis, and shading for energy management and conservation of residential building. Different modeling and simulation approaches, from various building and climate, were reviewed and discussed. The analysis of present work greatly help the researchers' decision-making and selection of software to perform various simulations in energy management of residential buildings.
Environment
H. Hassanpour; Z. Mortezaie; A. Beghdadi
Abstract
Video surveillance systems are widely used in the public and private sectors for maintaining security and healthcare purposes. Performance of surveillance systems directly depends on their accuracy in re-identification. There are three regions in a camera view, including person’s body, background, ...
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Video surveillance systems are widely used in the public and private sectors for maintaining security and healthcare purposes. Performance of surveillance systems directly depends on their accuracy in re-identification. There are three regions in a camera view, including person’s body, background, and possible carried object by the person. Background, in existing approaches, is either overlooked or treated like a person’s body in re-identification. In this paper, these three regions are considered in re-identification but with different importance. In our proposed technique, first, the input image is semantically segmented into the three regions using a deep semantic segmentation approach. Then, the effect of each region on characteristic features of people is tuned depending on the region’s importance in re-identification. The proposed technique, leveraging robust descriptors, such as the Gaussian of Gaussian (GOG) and Hierarchical Gaussian Descriptors (HGD), can enhance existing methods in dealing with the challenging issues such as partial occlusion caused by carried objects and background in re-identification. Experimental results on commonly used people re-identification datasets demonstrate effectiveness of the proposed technique in improving performance of existing re-identification methods.
Chemical Engineering
O. M. Abasili; U. C. Okonkwo
Abstract
Rolling process pelletizer which provides more efficient pelletizing technique that eases bio-fertilizers production had been designed. The designed mechanisms were centered on the dynamics of the machine components that consist mainly of links and joints. Tensions and loads were determined by following ...
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Rolling process pelletizer which provides more efficient pelletizing technique that eases bio-fertilizers production had been designed. The designed mechanisms were centered on the dynamics of the machine components that consist mainly of links and joints. Tensions and loads were determined by following the force balance equations. Bearings were selected from the SKF bearing catalogue by considering their positions, evaluation of the demands of the failure theories alongside with the dynamic load carrying capacities. Stability test was conducted on conveyor/mixing shaft of mass 11.2561kg and density 8000kg/m3 by fixing one end and applying pressure of 1.061x10-3N/mm2 towards the other end in line with demands of distortion energy theory. Frame stability test was also conducted by applying beam mesh that generated 354 nodes and 334 elements. Tension of 205.2N and 126.5N were calculated at the pulley. Various loads and moments acting on different shafts were determined and represented diagrammatically. Von mises stress of 1.847E+00N/mm2 on conveyor shaft and upper bound axial and bending stress of 2.759E+06N/m2 on the frame that was below material’s yield strength of 2.068E+08N/m2 based on the result of simulation test indicated stability of the design. The design is expected to function as well in similar production areas.
Energy
M. Pakdel; B. Alemi
Abstract
Silkworm cocoon is a natural biological and composite structure that has evolved over time and has high physical and mechanical properties against stress and acts as insulation against ambient temperature conditions. Understanding the relationships between the two-component structure of silkworm cocoons ...
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Silkworm cocoon is a natural biological and composite structure that has evolved over time and has high physical and mechanical properties against stress and acts as insulation against ambient temperature conditions. Understanding the relationships between the two-component structure of silkworm cocoons (sericin and fibroin) inspires the creation of composite structures, including lightweight, high-strength nonwoven biocomposites. In the present study, by analytical-descriptive method, we have tried to use cocoon sericin and introduce some famous and widely used natural fibers in materials science and study their characteristics - because for various reasons such as lightness, lack of pollution and low cost, etc. can be suitable alternative for a replacement of synthetic fibers - suggest the production of non-woven bio-composite materials. Natural fibers such as jute, hemp, flax, etc. with different volume percentages in combination with sericin as a binder, were proposed for this biocomposite and the thermal performance of each of them was compared using Maxwell's theoretical model. All compounds show low thermal conductivity and jute-sericin biocomposite with 70% by volume and 0.061 W/m2-K performance has better performance.
