S. N. Ashrafizadeh; Z. Seifollahi
Abstract
This article was written at the same time as the corona virus peaked in the country and during home quarantine, coinciding with the 40th day of the corona virus entering the country in April 2020, coincided with the Iranian new-year holidays. The purpose of writing this brief is to express sympathy with ...
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This article was written at the same time as the corona virus peaked in the country and during home quarantine, coinciding with the 40th day of the corona virus entering the country in April 2020, coincided with the Iranian new-year holidays. The purpose of writing this brief is to express sympathy with the earth and respond to her forgotten groans. A late but at the same time insignificant activity in the hope of healing the wounded conscience of inactive scholars such as current writers who hope to take positive action to preserve and protect the earth, the human ecosystem. The emphasis and purpose of this article is to exemplify national determination and mobilization in the fight against Corona for a higher purpose such as saving the earth and human life from catastrophe. In this regard, the teaching of environmental requirements in educational levels, the development of elite discourse in the framework of the formation of non-governmental organizations, and the use of scientific, cultural, and indigenous capacities as viable solutions have been proposed.
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 %.
N. Safaie; M. R. Saadatmand; S. A. Nasri
Abstract
Today, most industries use statistical quality control tools to improve quality and reduce the defective products and waste, but the high volume of data requires the help of a powerful tool to control processes. One of the objectives of the present study is to predict defective products and prevent their ...
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Today, most industries use statistical quality control tools to improve quality and reduce the defective products and waste, but the high volume of data requires the help of a powerful tool to control processes. One of the objectives of the present study is to predict defective products and prevent their production using data mining tools due to the high power in data analysis and its predictive nature, which is less used in the industry. In this study, the statistical population of all parts produced in 2017 by Shabrun Company. The statistical sample is 2400 pieces of radiators that were randomly selected from the production line. In the operational phases of data mining, three decision tree algorithms were used: C&R Tree, Quest Tree and Chaid Tree. Using these algorithms, the most important criteria affecting quality control and rules leading to the quality of parts were determined. Comparative results showed that despite the validity of all three algorithms, the C&R Tree algorithm had the highest accuracy. Adherence to the rules resulting from the implementation of these algorithms has led to the detection and prevention of waste generation, which has increased efficiency and prevented the loss of time and cost in this production unit.
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.
N. Sadafi; N. Jamshidi; M. Zahedian
Abstract
A building envelope plays a key role in controlling the internal environmental conditions. The evaluation of façade designs for naturally ventilated residential buildings in the temperate and humid climate of Iran was carried out to optimize façade design for energy saving. Firstly, the ...
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A building envelope plays a key role in controlling the internal environmental conditions. The evaluation of façade designs for naturally ventilated residential buildings in the temperate and humid climate of Iran was carried out to optimize façade design for energy saving. Firstly, the common types of building materials were identified through a field study. In the next step, a computer simulation was conducted to investigate the impact of façade design parameters, including U- values, window to wall ratio (WWR), the open able part of the window, and the length of shading devices on buildings energy consumption. The simulation results indicate that the building envelopes constructed with Lightweight Steel Framed (LSF), 3D Panels, and Autoclaved Aerated Concrete (AAC) blocks are more effective than the other investigated materials, for reducing heating and cooling loads of the building. Using these materials can reduce the energy consumption for heating and cooling by 45%. Large and unprotected windows increase the building energy demands and require additional control devices. Therefore, 25%WWR, with 300mm horizontal shading devices in four steps, light opaque internal curtains, and windows with low emission glass parts that are closed during noon and afternoon hot hours were suggested and analyzed for the studied climate.
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.
H. Zare; F. Meiguni; G. D. Najafpour
Abstract
Alkaline proteases are the most important groups of commercial enzymes, which have been broadly used in industrial processes. In this study, Bacillus sp. PTCC 1538 was selected as a biological agent to produce alkaline protease. Enzyme production under submerge fermentation using industrial waste effluent ...
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Alkaline proteases are the most important groups of commercial enzymes, which have been broadly used in industrial processes. In this study, Bacillus sp. PTCC 1538 was selected as a biological agent to produce alkaline protease. Enzyme production under submerge fermentation using industrial waste effluent was investigated. Since the costs of the raw material plays an important role in the cost of enzyme production, corn steep liquor (CSL) was selected as a low-cost substrate to reduce the cost of enzyme production. Various carbon sources were used as the auxiliary substrates to enhance enzyme production. Results showed that maximum enzyme activity was obtained when wheat bran was used as an auxiliary substrate. Optimal media composition and growth conditions for alkaline protease production were defined. The optimum conditions were found to be pH 8, incubation temperature of 37 °C, CSL inoculum size of 5 v/v %, yeast extract and wheat bran concentrations of 2 and 6 g/l, respectively. CaCl2 was used as an activator to enhance proteolytic activity of the enzyme. Under optimum condition, enzyme activity of 100.7 U/ml was obtained at CaCl2 concentration of 1.5 g/l.
Energy
M. R. Hayati; S. Ranjbar; M. R. Abdar; M. Molaei Nasab; S. Homayounmajd; M. Esmaeili Shayan
Abstract
With countries throughout middle east and north Africa pursuing ambitious targets for a transition to renewable energies, the political economy of a region predominantly analyzed through the prism of fossil fuels is on the verge of radical change. As hydrocarbon prices decline, the low-cost producers ...
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With countries throughout middle east and north Africa pursuing ambitious targets for a transition to renewable energies, the political economy of a region predominantly analyzed through the prism of fossil fuels is on the verge of radical change. As hydrocarbon prices decline, the low-cost producers of Middle East have an advantage and should be the last to leave the market. The world will demand proportionally more of the region’s oil and gas. Nearly half of the world's oil is located in Middle East, which has long been referred to as the "energy axis" of the planet. In the meanwhile, as the nations of this area progress towards the future, they have realized the need of supplying energy from these other sources, such that the utilization of renewable energy sources, such as the sun, has attracted considerable interest. This study analyzed and assessed these attractions in addition to five middle eastern nations and Turkey, which is located in middle east, close proximity to this area. The approach of comparing government incentives in the development of renewable power plants was used in this study. The final findings revealed the current status of this energy in the target nations. This study may give the target countries and other nations in the middle east with a wealth of information for the formulation of effective policies for the use of renewable resources.
N. Norouzi
Abstract
Hydrogen energy has the advantages of low carbon and cleanliness, high energy density, and high conversion efficiency; it is expected to play a pivotal role in Eastern Asia and the MENA region’s energy transition. The research status and development prospects of various technologies in hydrogen ...
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Hydrogen energy has the advantages of low carbon and cleanliness, high energy density, and high conversion efficiency; it is expected to play a pivotal role in Eastern Asia and the MENA region’s energy transition. The research status and development prospects of various technologies in hydrogen production, hydrogen storage, and hydrogen use are analyzed. On this basis, specific technical paths for developing renewable energy and integrated energy service parks coupled with hydrogen energy are proposed. Solid polymer electrolyte (SPE) electrolysis hydrogen production and solid material hydrogen storage are the most potential development in directions of hydrogen production and hydrogen storage. Technologies such as hydrogen fuel cell and natural gas hydrogen mixture in the hydrogen use link should be simultaneously promoted. The organic combination of wind/light-abandoned hydrogen production by electrolysis of water, wind power/photovoltaic off-grid hydrogen production with fuel cell power generation, hydrogen refueling station supply, methanol production, and natural gas hydrogen mixing technology would effectively solve the uneconomical and transportation difficulties of renewable energy hydrogen production. At the same time, hydrogen energy can realize the interconnection of multiple energy networks, and its application prospects in the future integrated energy service parks are very broad.
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.
M. E. Kazemian; S. A. Gandjalikhan Nassab; E. Jahanshahi Javarana
Abstract
In the present work, the statistical analyses are presented to study the economic indexes of Net Present Value (NPV) and Simple Payback Period (SPB) as response functions for the Combined Cooling, Heating and Power (CCHP) system. The CCHP performance is simulated with the aid of thermodynamic modeling, ...
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In the present work, the statistical analyses are presented to study the economic indexes of Net Present Value (NPV) and Simple Payback Period (SPB) as response functions for the Combined Cooling, Heating and Power (CCHP) system. The CCHP performance is simulated with the aid of thermodynamic modeling, and also economic equations are presented for economic simulation. An attempt is made to study the effect of some economic factors (interest ratio, fuel cost, lifetime, and electricity sell price) on the system’s responses. Based on the Design of Experiment analysis, regression models are presented to quantify the effects of these parameters on the Net Present Value and Simple Payback Periods. This novel approach is developed utilizing the response surface methodology (RSM) based on the central composite design (CCD) method. Sensitivity analysis of the economic parameters was also examined in this research. Optimal values of these parameters were obtained for the two economic indexes as response functions.
Energy
A. A. Sheikh Aleslami; H. Sadeghi
Abstract
Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical ...
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Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical simulation, the K-epsilon model has been used. The study evaluated the flow around the tower in several deformation states and compared it with a model where the tower is modeled rigidly in the wind tunnel. The maximum coefficient of negative pressure (suction) at the top of the tower structure equals to -1.95, which occurs at q =90o, and the maximum coefficient of the positive pressure equals +1. Since the buildings near the tower are located a short distance from the tower, the shed's structure, which is located near the tower, has also been investigated. With the aid of Tecplot software. The wind pressure coefficients obtained from the wind tunnel test were plotted. As part of the wind loading analysis in the single-span and two-span shed models, the model is rotated with a step of 5o relative to the direction of wind application, and wind pressure is recorded.
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.
M. Ameri; H. Farzan; M. Nobari
Abstract
Glass plates have been commonly used as collectors’ covers due to technical feasibility, high transmissivity in shortwave solar irradiation, and low transmissivity in long-wavelengths. However, they are vulnerable to stones and hail. Plastic plates have high transmissivity in shortwaves but also ...
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Glass plates have been commonly used as collectors’ covers due to technical feasibility, high transmissivity in shortwave solar irradiation, and low transmissivity in long-wavelengths. However, they are vulnerable to stones and hail. Plastic plates have high transmissivity in shortwaves but also have transmission bands in the middle of the thermal radiation spectrum. The current study represents an experimental assessment of different covering strategies, including single acrylic-cover, single glass-cover, double glass- acrylic cover, and double glass-cover. Two solar air heaters (SAHs) prototypes were constructed for this study. The acquired experimental runs illustrated that the single glass-covered SAH represents higher thermal performance than the single acrylic-covered SAH due to the lower transmissivity of glass plates in long wavelengths. The double-covered SAHs have higher performance than the similar single-covered SAHs. In the double-covered SAHs, the convective-radiant heat loss is reduced. However, increasing the cover number improves the radiant resistance to solar irradiation and reduces the collector performance when solar irradiation is insufficient and the absorber temperature is low, especially at the beginning of daytime hours. The SAH using a double-glass cover is preferable; however, the heat dynamics of the double glass- acrylic-covered SAH are so close to the double glass-covered one, and the acrylic plate is more resistant to harsh ambient conditions.
Energy
N. Deb; M. Z. Alam; T. Rahman; M. S. Jami; M. F. Bt. Mansor; H. B. A. Tajuddin
Abstract
The world's most economically developed countries are facing an energy crisis caused by geopolitical instability, rising energy costs, global stock disruptions, and a shift towards low-carbon energy sources that has yet to be fully realized. Electrification of the transportation industry offers the advantages ...
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The world's most economically developed countries are facing an energy crisis caused by geopolitical instability, rising energy costs, global stock disruptions, and a shift towards low-carbon energy sources that has yet to be fully realized. Electrification of the transportation industry offers the advantages of increased energy efficiency and reduced local pollutants. Electric Vehicles (EVs) are environmentally friendly because they reduce fossil fuels usage even zero consumption, need fewer maintenance requirements, and lower operating costs than the vehicles powered by gasoline or diesel. However, this study focuses on comparing various energy management strategies (EMS) for a backup energy supply system for EVs. The hybrid power system (HPS) considered in this study includes DC-DC and DC-AC synchronous converters, as well as supercapacitors, batteries, and fuel cells. The EMS analyzed includes state machine control, classical proportional-integral control, equivalent consumption minimization, frequency decoupling, rule-based fuzzy logic, and fuzzy logic control. The HPS's efficiency, hydrogen fuel, supercapacitor or battery state of charge levels, and overall performance are evaluated as primary efficiency criteria. Additionally, the HPS not only increases system energy but also reduces the number of pack batteries required. This study designs and constructs the combined power systems to enhance EV power schemes with rechargeable battery power supplies. The results show that a 6-kW fuel cell hybrid increases the power system capacity to 408 kWh. Moreover, a novel method based on wavelet transforms of the instantaneous power of each energy source is used to quantify the stressors on each energy source that impact its life cycle. To validate all analyses and performance, a simulation model and an experimental test bench are created. Finally, simulation results demonstrate a synchronous converter with a 6-kW output power and 96% efficiency, validating the optimization results.
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.
S. D. Farahani; M. Alibeigi; M. R. Sabzehali
Abstract
The turbofan engines are one of the constitutes significant components of the aero engines. In this study, the thermodynamic modeling of the TF30-P414 turbofan engine is developed and validated with reference values. The aims of this research are to determine the effect of the changes in the thrust, ...
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The turbofan engines are one of the constitutes significant components of the aero engines. In this study, the thermodynamic modeling of the TF30-P414 turbofan engine is developed and validated with reference values. The aims of this research are to determine the effect of the changes in the thrust, fuel mass flow rate, and thermal efficiency with changes of the flight-altitude (H) and the flight-Mach number (Ma). Then, the changing of the exergy efficiency and exergy destruction rate were investigated. The results show that between the different components of the engine in different flight circumstances, the highest exergy destruction occurred in the combustion chamber and the lowest exergy destruction occurred in the nozzle. Also, optimization with the objective function of finding optimum flight conditions to find the highest exergetic efficiency in the flight-Mach number of 1.2 to 2.2 and the flight altitude of 10,000 to 15,000 meters. The results of this optimization reported that the maximum exergetic efficiency happened to the conditions of H=11236 meters and Ma=1.944 with an amount of 32.64%.
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.
Environment
A. Sezavar; H. Farsi; S. Mohamadzadeh
Abstract
Person re-identification (re-id) is one of the most critical and challenging topics in image processing and artificial intelligence. In general, person re-identification means that a person seen in the field of view of one camera can be found and tracked by other non-overlapped cameras. Low-resolution ...
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Person re-identification (re-id) is one of the most critical and challenging topics in image processing and artificial intelligence. In general, person re-identification means that a person seen in the field of view of one camera can be found and tracked by other non-overlapped cameras. Low-resolution frames, high occlusion in crowded scene, and few samples for training supervised models make re-id challenging. This paper proposes a new model for person re-identification to overcome the noisy frames and extract robust features from each frame. To this end, a noise-aware system is implemented by training an auto-encoder on artificially damaged frames to overcome noise and occlusion. A model for person re-identification is implemented based on deep convolutional neural networks. Experimental results on two actual databases, CUHK01 and CUHK03, demonstrate that the proposed method performs better than state-of-the-art methods.
Environment
R. A. Olaoye; S. O. Ojoawo; O. Bamigbade; N. Alimi; I. O. Rasaq; T. Oladejo
Abstract
The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most ...
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The adhesion of metal ions from wastewater to surface of a material in an adsorption process had proven to be effective for remediation of wastewater before discharge. There is a growing demand to utilize alternative low-cost adsorbents for the removal of heavy metals from galvanic wastewater in most developing countries. Cow bones are cheap, readily available and can be sourced locally from slaughterhouses and abattoir. Therefore, their use as an alternative adsorbent for remediation of galvanic wastewater had to be assessed. In this study, the efficacy of cow bone char (CBC) was assessed for simultaneous heavy metal ions removal from real life galvanic wastewater in a competitive adsorption process. The galvanic wastewater was characterized using atomic adsorption spectrophotometry while the CBC was characterized using X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR). Batch experiment was performed to determine the effect of adsorbent dose, contact time and agitation speed on the removal efficiency of heavy metal ions from the galvanized wastewater. The concentrations of Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+ in the raw wastewater exceeded the WHO and EPA standards. The adsorbent revealed a significant distribution of well-developed porous, rough surfaces with cracks characterized by different functional groups for the efficient adsorption process. The optimum adsorbent dose for all the metal ions was 0.04 g/100 mL at an optimum contact time of 60 minutes except for Fe2+ with optimum contact time of 20 minutes, and agitation speed of 150 rpm. The maximum metal removal efficiencies obtained for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2were 99.7%, 100%, 99%, 90% and 85% +, respectively. The average adsorption capacity for Mn2+, Fe2+, Zn2+, Pb2+ and Cr2+were 0.44 mg/g, 26.7 mg/g, 78.5 mg/g, 0.133 mg/g for and 10.36 mg/g, respectively. CBC offers efficient and cost-effective removal of selected metal ions from galvanized wastewater.
Energy
N. Tayari; M. Nikpour
Abstract
Most of the spaces in contemporary houses in Iran cannot achieve enough daylight during daytime. Daylight utilization has a significant impact on decreasing energy consumption in residential buildings. Residents are deprived of natural daylight when there is no attention to the design based on daylight. ...
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Most of the spaces in contemporary houses in Iran cannot achieve enough daylight during daytime. Daylight utilization has a significant impact on decreasing energy consumption in residential buildings. Residents are deprived of natural daylight when there is no attention to the design based on daylight. Iranian traditional architects use practical and straightforward methods in constructing courtyards houses to provide comfort conditions in unique rooms in courtyard houses in terms of daylight quality. In this research, the daylight quality of five separate rooms around the courtyard of Yazdanpanah's house was investigated through an experimental method. Average work plane illuminance and uniformity ratio were calculated in these rooms of the house in Kerman city, located in Iran's hot and dry climate. Findings of this research demonstrated that all rooms surrounding the courtyard of traditional houses have the ability to achieve work plane illuminance of more than acceptable value. Among all rooms around the central courtyard, one room facing the south direction achieves more than 500 Lux work plane illuminance. The amount of uniformity in this room is acceptable with more than 0.5 on most of the days in a year. The findings of this research could be used to design more comfortable rooms in contemporary houses in terms of daylight quality by creating central courtyards.
Environment
M. Heydari; T. Tabatabaie; F. Amiri; S. E. Hashemi
Abstract
Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. ...
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Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. In this context, using adsorption processes is a potential alternative for treating a wide range of organic pollutants, especially aromatic compounds in industrial wastewater. This study investigated the preparation of MCM-41 from silica; extracted from rice husk ash; MCM-41 was green synthesized to evaluate the effect of mesoporous used in BTEXS removal of an aqueous medium using the Taguchi method. The aqueous solution contains cyclic hydrocarbons was synthetically prepred based on real industrial effluent in concentrations of 50, 100, and 150 mg/l using MCM-41 catalysts, in doses of 0.1, 0.5, and 1g, at different pH values. In the present study, the optimum results obtained by Taguchi method analysis were pH =11, for duration of 60 minutes, the concentration of cyclic hydrocarbon solution BTEXS 100 mg/l, and nanoparticle dose of 0.5 g. The maximum BTEXS removal of 77.36% was achieved by the use of hydrogen peroxide.
Chemical Engineering
N. Hedayati; A. Ramiar
Abstract
The challenge of particle deposition in microchannels has consistently posed issues in nanofluids, adversely impacting the heat transfer rate. This study investigates the novel approach of employing a magnetic field to prevent deposition and enhance the heat transfer of nanoparticles in microchannels, ...
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The challenge of particle deposition in microchannels has consistently posed issues in nanofluids, adversely impacting the heat transfer rate. This study investigates the novel approach of employing a magnetic field to prevent deposition and enhance the heat transfer of nanoparticles in microchannels, utilizing Euler-Lagrange method. The analysis involves the coupled solution of momentum and energy equations, incorporating forces such as Brownian motion, thermophoresis, drag, and volumetric force. The findings within the explored parameters indicate that temperature variations affecting particles beyond the thermal boundary layer have a comparatively minor impact compared to those within the boundary layer. This presents an opportunity for optimizing nanoparticle consumption. Additionally, the study reveals that a non-developed flow at the inlet results in lower particle deposition compared to a developed inlet. The results show that an increase in the Reynolds number from 50 to 300 leads to a 1.75% increase in the distance of particles from the wall. The study also delves into the positioning of the current-carrying wire, demonstrating that placing the wire at the microchannel entrance significantly reduces particle deposition. Furthermore, the results indicate that with an increase in electrical current up to 4 amperes, the efficiency of non-deposition reaches 100%.
S. Abdoli Naser; F. Haghparast; M. Singery; H. Sattari Sarbangholi
Abstract
Windows in the building are the biggest elements of heat loss through convective heat transfer. The purpose of study is to select appropriate dimensions for windows relative to shell and appropriate glazing for windows, in order to achieve optimal pattern to reduce energy consumption. The research method ...
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Windows in the building are the biggest elements of heat loss through convective heat transfer. The purpose of study is to select appropriate dimensions for windows relative to shell and appropriate glazing for windows, in order to achieve optimal pattern to reduce energy consumption. The research method is based on the simulation and research tool is DesignBuilder software. Therefore, amount of natural gas consumed annually in the studied building was received from the National Iranian Gas Company and then the basic research was modeled by software and after converting unit from kWh to m3 and validating simulation results. In the next step, the range of 20% to 80% of window-to-wall-ratio, types of glazing and window height is considered and through parametric optimization, all conditions in the windows are simulated and analyzed for sensitivity index. The calculations confirm that in an intermediate residential building with a rotation of 12 degrees to the southeast in Tabriz, by reducing window-to-wall-ratio from 50% to 20% and replacing triples-glazed-glazing with a low-emission coating filled with argon gas with a transparent single-glazed glazing and UPVC frame and a canopy with a depth of 48cm and windows height of 1.5m, the heat losses were reduced by 60.34% and 75.24%, respectively.
