Environment
R. Farhadi; M. Hadavifar; M. Moeinaddini; M. Amintoosi
Abstract
Today, air pollution in urban areas is a major issue that have been affecting human health and the environment. Over the years artificial neural network methods has been used for prediction of pollutants concentration in many metropolitans. In the present study data were obtained from department of environment ...
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Today, air pollution in urban areas is a major issue that have been affecting human health and the environment. Over the years artificial neural network methods has been used for prediction of pollutants concentration in many metropolitans. In the present study data were obtained from department of environment and air quality controlling stations in city of Tehran from March 2012 to October 2013. Prediction of CO and PM10 contaminations during cold and warm seasons under the influence of instability indices and meteorological parameters was done using the artificial neural network. Results of the modeling process showed that the highest correlation coefficient was obtained 0.84 for PM10 in warm season. On the contrary, the highest correlation coefficient of CO in cold season was 0.78. Also, the effect of instability indices on air pollution was investigated. The highest CO concentration occurred during cold seasons (R2= 0.81), while the lowest concentration was in warm season (R2= 0.72). In case of PM, the highest concentration occurred during warm seasons (R2= 0.84), while the lowest concentration was in cold season (R2=0.75).
Energy
F. Najjari Seresht; A. Hakimi Oskui; S. Salkhi; E. Imani
Abstract
The building envelope is one of the most influential factors in energy consumption. Therefore, optimizing the facade of the building with new technologies is one of the most effective passive solutions to provide thermal comfort. The purpose of this research is to design a composite facade, which according ...
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The building envelope is one of the most influential factors in energy consumption. Therefore, optimizing the facade of the building with new technologies is one of the most effective passive solutions to provide thermal comfort. The purpose of this research is to design a composite facade, which according to the two main driving forces; the pressure difference caused by the heat flow (air flow and wind force) and the insulation of the air, for a residential building with a typical plan of Yazd in the hot and dry climate of Iran. That can be used to reduce the heating and cooling load of the building. For this purpose, firstly, the effect of two types of two-skin facades - floor-to-floor and all-over two-skin facades - compared to the model without two-skin facades in cooling and heating energy consumption throughout the year was modeled and analyzed with Design Builder version 6.1 software. The results of the constructions show the possibility of reducing about 60% of cooling energy through the creation of air conditioning and 26% of heating energy through the creation of thermal insulation in the residential building simulation model throughout the year by means of two combined shells. The findings of this research lead to the creation of more efficient energy solutions by creating innovation and combining new technologies according to climatic conditions.
Environment
T. Yahaya; O. Ologe; C. Yaro; L. Abdullahi; H. Abubakar; A. Gazal; J. Abubakar
Abstract
The increasing prevalence of water-borne diseases necessitates periodic monitoring of domestic and drinking water sources. The current study assessed the safety of well water in the four emirate zones (Gwandu, Yauri, Argungu, and Zuru) of Kebbi State, Nigeria. Using normal procedures, samples of well ...
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The increasing prevalence of water-borne diseases necessitates periodic monitoring of domestic and drinking water sources. The current study assessed the safety of well water in the four emirate zones (Gwandu, Yauri, Argungu, and Zuru) of Kebbi State, Nigeria. Using normal procedures, samples of well water were examined for heavy metals, physicochemical characteristics, and microorganisms, and the results were compared to the World Health Organization (WHO) drinking water criteria. The heavy metals’ chronic daily ingestion (CDI) and hazard quotient (HQ) were also determined. The results showed that well water in the four emirate zones had normal temperature, biochemical oxygen demand (BOD), dissolved oxygen (DO), total suspended solids (TSS), and zinc (Zn). However, non-permissible concentrations of lead (Pb), iron (Fe), cadmium (Cd), chromium (Cr), and pH (Gwandu and Argungu only) were detected in all the water samples. Except for Cd and Cr in children, the CDI and HQ of the heavy metals were normal. The microbiological examinations revealed that the water samples from the four zones had abnormal levels of Bacillus species (bacteria), Escherichia coli (bacteria), Staphylococcus aureus (bacteria), Aspergillus niger (fungi), Mucor racemosa (fungi), and Paecilomyces variotti (fungi). The results obtained suggest that well water in the four zones is not suitable for human consumption unless treated.
F. Al-Badaii; A. Abdul Halim
Abstract
In this study, drinking water sources including drilled wells (DW), water tankers (WT), stabilized water tanks (SWT), and plastic bottles (PB) as sequential sample were assessed at Dhamar City, Yemen to investigate the microbial contamination and the potential risk of contamination using microbial indicators ...
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In this study, drinking water sources including drilled wells (DW), water tankers (WT), stabilized water tanks (SWT), and plastic bottles (PB) as sequential sample were assessed at Dhamar City, Yemen to investigate the microbial contamination and the potential risk of contamination using microbial indicators and multiple antibiotic resistance index. The sequential sample involving, 5 drilled wells, 10 water tankers, 20 water tanks, and 100 plastic bottles. The study encompassed five sequential samples. Each water sample was collected in triplicate and analyzed for E.coli as a microbial indicator and antibiotic susceptibility testing. Results indicated that all the water samples were contaminated by E.coli and total coliform exceeded the acceptable levels recommended by WHO of microbial quality of drinking water. E.coli isolates (240) showed high resistance to the tested antibiotics comprising 79.82% to ampicillin, 78.32% to gentamicin, 67.5% to ceftriaxone, 19.98% to ciprofloxacin, 18.32% to amoxiclav, and 33.34% were resistant to tetracycline. The multiple antibiotic resistance index of E. coli that showed resistant to three antibiotics ranged from 0.19 to 0.24 for all the tested samples and exceeded the threshold value of 0.2 for all samples except sequential sample 4, indicating a high risk of contamination for drinking water effected by anthropogenic activities related to urbanization, accumulation of microbial contamination during the various transferring processes of water from the source into households, as well as misuse and greater exposure to antibiotics in humans and poultry farms, which may pose a high ecological risk to the waters.
Energy
M. Esmaeili Shayan; G. Najafi; B. Ghobadian; S. Gorjian
Abstract
Photovoltaic cells are a significant renewable energy source due to their cheap cost and renewability. In both warm sunny and colder and cloudier conditions, a-Si modules outperform c-Si modules on a normalized energy basis. This study investigated 1 m2 of amorphous photovoltaic silicon on curved surfaces. ...
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Photovoltaic cells are a significant renewable energy source due to their cheap cost and renewability. In both warm sunny and colder and cloudier conditions, a-Si modules outperform c-Si modules on a normalized energy basis. This study investigated 1 m2 of amorphous photovoltaic silicon on curved surfaces. The Taguchi and response surface methods were utilized to expand the model in real terms. Results demonstrated the technology gap in the use of silicon crystal photovoltaics is eliminated. The maximum power in the Taguchi method test is 59.87 W, while the minimum power is 57.84 W when the system is deployed on a flat surface, and the maximum power in the RSM Test is 61.14 W when the system is deployed on a hemispherical surface, and the minimum power is 56.6 W when the system is deployed on a flat surface. The minimal performance was 7.1% on a level surface. The flat surface produced 810 kWh, the cylindrical surface 960 kWh, and the hemisphere 1000 kWh. The NPV at Flat surface is $697.52, with a 34.81%, IRR and an 8.58-year capital return period. Hemisphere and cylindrical surfaces both get $955.18. The investment yield was 39.29% for cylindrical constructions and 40.47% for hemispheres. On the flat surface, doubling fixed investment improved IRR by 21.3%. The cylindrical system increased by 25.59% and the hemisphere by 24.58%. The developed simulation model is empirically evaluated using a MATLAB computer tool; the key findings from the validation procedure are reported in this study.
Environment
Z. Dorrani; H. Farsi; S. Mohamadzadeh
Abstract
In traffic monitoring for video analysis systems, vehicle shadows have a negative effect on their performance. Shadow detection and removal are essential steps in accurate vehicle detection. In this paper, a new method is proposed for shadow detection using a novel convolution neural network architecture. ...
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In traffic monitoring for video analysis systems, vehicle shadows have a negative effect on their performance. Shadow detection and removal are essential steps in accurate vehicle detection. In this paper, a new method is proposed for shadow detection using a novel convolution neural network architecture. In the proposed method, the edges of the image are first extracted. Edge extraction reduces calculation, and accelerates the execution of the method. The background of the frame is then removed and the main features are extracted using the ResUNet-a architecture. This architecture consists of two parts: the encoder and the decoder, which detect the shadow at the decoder output and then remove it. Deep learning is used to detect shadows, which increases the accuracy of the analysis. The ResUNet-a architecture can learn complex, hierarchical, and appropriate features from the image for accurate feature detection and discarding the irrelevant shadow, thereby outperforming conventional filters.The results show that the proposed method provides better performance on NJDOT traffic video, highway-1, and highway-3 datasets than popular shadow removal methods. Also, the method improves the evaluation criteria such as F-measure and runtime. The F-measure is 94 and 93% for highway-1 and highway-3, respectively.
Y. Yousefi; H. Amonia; K. Ghaffari
Abstract
One of the most important factors in energy consumption is environmental conditions.This study aims to examine the relationship between temperature and electricity consumption in Babolsar city in Mazandaran province. The main issue in this study is to find different patterns of relationship between temperature ...
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One of the most important factors in energy consumption is environmental conditions.This study aims to examine the relationship between temperature and electricity consumption in Babolsar city in Mazandaran province. The main issue in this study is to find different patterns of relationship between temperature and electricity consumption in this city. Daily electricity consumption and daily temperature, were collected from 1 Jan 2010 to 31 Dec 2019, from the Electricity Department and the Babolsar Synoptic Station. Threshold regression method was used to find the breakpoints of the regression line between temperature and power consumption. Findings revealed there were 3 distinct thresholds in the relationship between consumption and temperature. The first threshold was about
Energy
H. Eskandari; S. N. Mosavian
Abstract
This research, conducted in Gotvand, southwest of Iran, compared the energy consumption of two cucumber production systems: field and greenhouse production systems. In this study, energy inputs of two production systems of cucumber (including seed, pesticide, human labor, machinery, diesel fuel, electricity, ...
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This research, conducted in Gotvand, southwest of Iran, compared the energy consumption of two cucumber production systems: field and greenhouse production systems. In this study, energy inputs of two production systems of cucumber (including seed, pesticide, human labor, machinery, diesel fuel, electricity, organic manure, chemical fertilizer) were determined from questionnaires completed by farmers. The results of the experiment indicated that the energy input of the two cultivation systems was not significantly different in input energies. In both cucumber production systems, the most input energy was allocated to nitrogen fertilizer (57% and 53% for field and greenhouse, respectively) followed by diesel fuel (21% in both production systems). Non-renewable energies accounted for 90 and 88% of the total energy input to the farm and greenhouse systems, respectively. Total output energy of field and greenhouse cucumber production system was 33000 and 34000 MJ, respectively. Reducing the consumption of nitrogen fertilizer through the use of appropriate crop rotation is a suitable solution to improve energy efficiency in the cucumber production system.
Energy
S. Naranjo-Silva; D. Punina-Guerrero; J. Barros-Enriquez; J. Almeida-Dominguez; J. Alvarez del Castillo
Abstract
The present manuscript aims to identify the advantages and consequences of hydropower development, showing a view of trends finding the status and situation in Brazil, Colombia, and Ecuador. This study uses a non-experimental methodology based on a comprehensive literature review of relevant papers retrieved ...
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The present manuscript aims to identify the advantages and consequences of hydropower development, showing a view of trends finding the status and situation in Brazil, Colombia, and Ecuador. This study uses a non-experimental methodology based on a comprehensive literature review of relevant papers retrieved from 41 selected papers that are summarized covering different application areas in these selected countries. In addition, the non-experimental methodology is guided by a perspective design sequential with a qualitative phase defining two indicators that do a relation between the people and the installed capacity in megawatts (MW) and energy production in gigawatts hour (GWh). The results show Colombia has the main installed capacity and energy generation per capita, followed by Ecuador, and finally, Brazil. According to the models and studies, the general hydropower potential of Brazil, Colombia, and Ecuador decreases as time goes on because this renewable energy affects the water quality, interacting deeply with the surrounding environment. However, in South American countries only 34% of hydropower potential has developed.
Water Resources Engineering
S. Mahmood; M. M. Saeed; Z. Kılıç; M. Iqbal; H. A. Rehman
Abstract
With surge irrigation, applying surges to an area is a cheap labor task. In industrialized nations, a variety of electronic valves for discontinuous water application (surges) are available; but their pricing prevents their usage in emerging regions. Additionally, these valves are too advanced for use ...
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With surge irrigation, applying surges to an area is a cheap labor task. In industrialized nations, a variety of electronic valves for discontinuous water application (surges) are available; but their pricing prevents their usage in emerging regions. Additionally, these valves are too advanced for use by growers in underdeveloped nations. As a result, a basic Automatic Surge Gate was developed and tested in the labs to assess its effectiveness in terms of producing on-off surges. The reservoir was built to hold or collect low inflows for barrier functioning, and the gate was positioned on the suction side of the reservoir. Inflow rates, pinions, and poundage placements on the gate lever were the working parameters defined for the gate functioning. In the current investigation, three inflow rates 134, 169, and 187 l/s were employed. By leveraging the low inflows to the reservoir, the automatic surge gate demonstrated the possibility for automating the on-off action. The surge gate produced sizeable outflows even at the lowest inflow rate of 134 l/s into the reservoir. Power-law equations were discovered to be a good representation of the behavior in the statistical models that were also created using quasi statistical method.
Energy
A. Kamyab; M. Mahmoodi Zarandi; M. Nikpour
Abstract
The city of Yazd has a large number of traditional houses. Houses with central courtyards and an Iwan were suitable for establishing thermal comfort conditions. In this research, the effect of Iwan's depth and the ratio of the adjacent room's openings on the comfort condition in the residential courtyard ...
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The city of Yazd has a large number of traditional houses. Houses with central courtyards and an Iwan were suitable for establishing thermal comfort conditions. In this research, the effect of Iwan's depth and the ratio of the adjacent room's openings on the comfort condition in the residential courtyard buildings in Yazd city were evaluated. The current research aims to provide an optimal model of the Iwan to increase sustainable development and use such models as the Iwan in contemporary housing in the hot and dry climate of Yazd. In order to investigate the effect of parameters, samples from the north-facing room and south-facing room in a central courtyard model with different proportions of the Iwan and different sizes of the window were simulated in Design Builder software. The results showed that the depth of Iwan and window to wall ratio's (WWR) of the adjacent room’s window significantly affects the comfort (according to cooling load, heating load, and energy consumption) in this room. The results obtained in this research will be a new window to recover the concepts of old patterns and help to solve climate problems.
Chemical Engineering
M. Zamani; R. Shafaghat; B. Alizadeh Kharkeshi
Abstract
Due to the necessity of utilizing renewable energies, the Archimedes screw turbine can be used as a power generation converter for the use of hydropower energy from river flows. A laboratory-scale model of this turbine with a scale of 1:6 has been designed and constructed. In the experimental tests, ...
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Due to the necessity of utilizing renewable energies, the Archimedes screw turbine can be used as a power generation converter for the use of hydropower energy from river flows. A laboratory-scale model of this turbine with a scale of 1:6 has been designed and constructed. In the experimental tests, the performance characteristics of the turbine were investigated based on variations in the flow rate and electrical resistance. The optimal flow rate for the turbine was determined with the aim of achieving maximum efficiency. The performance characteistics of the turbine at this flow rate were evaluated using empirical equations derived from the experimental tests for various parameters. These equations indicated higher values for these parameters at this flow rate. Furthermore, for the scaling of the Archimedes screw turbine, dimensionless numbers such as Froude number and flow rates ratio were introduced. The experimental results were extrapolated to the prototype scale at the optimal flow rate of 2.6 (lit/s), where the maximum turbine efficiency occurs. The results showed that the use of Froude scaling led to approximately 25% higher values for the performance characteristics of the turbine compared to scaling based on flow rates ratio.
Energy
A. Habibzadeh; M. Abbasalizadeh; I. Mirzaee; S. Jafarmadar; H. Shirvani
Abstract
In this study, renewable energy sources including a high-temperature solar parabolic trough collector and geothermal water integrated with a modified Kalina cycle, a combined ORC-EJR cycle, an electrolyzer, an RO desalination unit, and a domestic water heater. SiO2 and TiO2 nanoparticles dissolved in ...
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In this study, renewable energy sources including a high-temperature solar parabolic trough collector and geothermal water integrated with a modified Kalina cycle, a combined ORC-EJR cycle, an electrolyzer, an RO desalination unit, and a domestic water heater. SiO2 and TiO2 nanoparticles dissolved in Therminol VP1 are applied as the working fluid of the solar collector. A comparative analysis of introduced working fluids is performed from energy, exergy as well as cost analysis point of view to evaluate their efficiencies. Solar irradiation, ambient temperature, and collector inlet temperature were the parameters investigated to discover their effects on energy and exergy efficiency, solar collector outlet temperature, hydrogen production rate, and freshwater production rate. The highest generated outlet temperature of the solar collector outlet was 693.8 K obtained by Therminol VP1/SiO2 nanofluid. The maximum energy and exergy efficiencies of the proposed system were 36.69 % and 17.76 %, respectively. Moreover, it is found that by increasing the solar collector inlet temperature, the hydrogen production rate decreases while the water production rate increases.
Energy
A. Mohammadi; M. Hakimizadeh
Abstract
Gas hydrate formation is a new technology to uptake carbon dioxide. In the present work, the kinetics of changes in the volume of unreacted water, the formed carbon dioxide hydrate, and also the unreacted gas inside the reactor were investigated with the passage of time. Experiments were performed in ...
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Gas hydrate formation is a new technology to uptake carbon dioxide. In the present work, the kinetics of changes in the volume of unreacted water, the formed carbon dioxide hydrate, and also the unreacted gas inside the reactor were investigated with the passage of time. Experiments were performed in a stagnant 169 cm3 double-walled reactor at a temperature of 275.15 K and a pressure of 3 MPa. The tests were done by using the isochoric-isothermal method. The results of the experiments showed that the volume of unreacted water decreased with respect to time and the volume of hydrate formed increased. Taking into account the different molar volumes of hydrate formed and the molar volume of reacted water in the test conditions, the changes in gas volume inside the reactor were calculated with the passage of time. The gas volume inside the reactor decreased from 144 cm3 at the beginning of the process to 141.62 cm3 at the end of the reaction. By decreasing the pressure during carbon dioxide hydrate formation process, the amount of hydration number increased from 6.047 mol/mol to 6.109 mol/mol.
Energy
M. Beykani; R. Shafaghat; A. Yousefi
Abstract
This paper investigates the effect of the immersion ratio parameter on the hydrodynamic performance of three surface-piercing propellers with diameters of 0.125, 0.132 and 0.140m at different advancing speeds. Experimental tests have been carried out in the free surface water tunnel of the Babol Noshirvani ...
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This paper investigates the effect of the immersion ratio parameter on the hydrodynamic performance of three surface-piercing propellers with diameters of 0.125, 0.132 and 0.140m at different advancing speeds. Experimental tests have been carried out in the free surface water tunnel of the Babol Noshirvani University of Technology. The results showed that the maximum thrust coefficient of three propellers occurs in the velocity range of 3-3.5 m/s. This interval represents the transition area of the three propellers. Also, the effect of the blockage ratio on the hydrodynamic coefficients of three propellers relative to the advance coefficient has been studied. By increasing the immersion depth raises the propeller's wet surface and increases the thrust and torque hydrodynamic coefficients. However, growing the propeller's diameter to 0.140m causes the effect of the blockage ratio parameter by increasing the immersion and the propeller's torque experiences a decreasing trend. Therefore, maximum propeller efficiency value with diameter 0.140m in immersion ratio 0.60 and 0.70, incresing 38% and 44%, respectively; relative to other proepllers. Also, the curve of the efficiency gradient of three propellers in the optimum immersion ratio of 0.40 compared to the advancing coefficient shows that the maximum efficiency gradient occurs in the range of 0.7 to 0.9.
Chemical Engineering
A. Graeeli; M. Rahimi-Esbo; V. Kord Firouzjaee; M. Sedighi; M. Rezaee Firouzjaee
Abstract
Considering the escalating significance of hydrogen production as a high-energy-density fuel, coupled with the challenges associated with its transportation and storage, the necessity to generate hydrogen at the point of consumption has become more pronounced than ever before. Thus, this research endeavors ...
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Considering the escalating significance of hydrogen production as a high-energy-density fuel, coupled with the challenges associated with its transportation and storage, the necessity to generate hydrogen at the point of consumption has become more pronounced than ever before. Thus, this research endeavors to comprehensively investigate various hydrogen production processes and elucidate the merits and drawbacks of each technique. Additionally, the catalysts employed in these processes were examined, ultimately leading to the selection of methanol steam reforming using a Cu/ZnO/Al2O3 catalyst within a fixed bed reactor for hydrogen production. Subsequently, the process underwent initial simulation utilizing Aspen Plus software, enabling a close-to-reality assessment of the simulation's challenges. Following the validation of the simulation results, a comparative analysis was conducted between a reactor operating at a specified temperature (T=220℃) and a co-current reactor. Each reactor possessed distinct advantages and disadvantages. Through this comparison, it was observed that, in order to achieve the same conversion, the length of the co-current reactor could be reduced by 5.7 cm compared to the specified temperature reactor. Consequently, the construction cost was reduced; however, this modification resulted in an increased production of carbon monoxide, necessitating further investigation.
Environment
O. F. Anjorin; L. C. Imoh; C. Uhunmwangho
Abstract
Since actual metal emissions can be assessed using Particulate matter (PM) as a proxy, monitoring and controlling metal compounds in biomass emissions is essential for determining their quantities and potential health effects. Using a low volume respirable dust sampler, indoor ambient metal-bearing particles ...
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Since actual metal emissions can be assessed using Particulate matter (PM) as a proxy, monitoring and controlling metal compounds in biomass emissions is essential for determining their quantities and potential health effects. Using a low volume respirable dust sampler, indoor ambient metal-bearing particles were quantified in-situ and collected from nine (9) randomly selected public kitchens of boarding secondary schools in Jos, Plateau State. Atomic absorption spectrometry (AAS) was used to determine the amounts of specific heavy metals in these collected samples. Additionally, 114 responders' blood samples underwent a biochemical lead assay study. The mean concentrations of the samples taken for Mn, Cd, Cu, Fe, Cr, Zn, Ni, Pb, and Co were 0.097, 0.015, 0.254, 0.314, 1.027, 0.000, 0.076, 0.106, and 0.169 µg/m3, respectively. The results of the blood lead assay analysis showed that 54% of the subjects had B-Pb levels above 80 µg/dL, 33% had B-Pb levels between 40 µg/dL and 80 µg/dL, 8% between 25 µg/dL and 40 µg/dL, 4% between 10 µg/dL and 25 µg/dL, 4% below 10 µg/dL, and 15% below 10 µg/dL. In general, elevated levels of metal-bearing particles in the indoor environment public kitchens expose kitchen staff to several occupational hazards.
Wastewater
N. Masne; S. Suryawanshi
Abstract
In this study, natural coarse aggregates were replaced with coarse recycled concrete aggregate (RCA) in 0 %, 50 %, and 100 % extracted from construction and demolition wastes. Their recycling could lead to a greener resolution for preserving the environment and paving the way for sustainability through ...
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In this study, natural coarse aggregates were replaced with coarse recycled concrete aggregate (RCA) in 0 %, 50 %, and 100 % extracted from construction and demolition wastes. Their recycling could lead to a greener resolution for preserving the environment and paving the way for sustainability through solid waste management. The compressive strength of 0 %, 50 % and 100 % RCA at 365 days was reduced by 3.97 %, 4.88 %, 6.81 %, respectively, compared to the compressive strength at 28 days. Tensile strength at 365 days was reduced by 4.31 %, 6.50 % and 9.83 % compared to tensile strength at 28 days. There was no discernible effect of water type on the strength properties of concrete. Compared to other combinations, 100 % RCA concrete experiences a greater percentage of weight loss owing to evaporation of free water. When temperature was elevated, the concrete matrix expands and deep cracks were observed on the concrete surface. The overall performance of recycled aggregate concrete was not much influenced by the use of such aggregates, so these findings will add a new achievement to a sustainable construction through solid waste management.
Environment
A. Ghalehnovi; H. Kamelnia
Abstract
Today, the focus on the sustainability issue in universities has become of significance considering the climatic and environmental issues. Therefore, universities are moving toward uniting the sustainability methods in their systems. Currently, many universities in Iran are performing essential activities ...
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Today, the focus on the sustainability issue in universities has become of significance considering the climatic and environmental issues. Therefore, universities are moving toward uniting the sustainability methods in their systems. Currently, many universities in Iran are performing essential activities in relation to environmental issues. This study is to determine the share of universities in sustainability quantitatively, and then it analyzes their activities. This research evaluates their activities in two steps based on the clustering and the efficiency of their performance. In the first step, the universities are grouped into homogenous clusters based on hierarchical clustering method with regards to their activities in sustainability area. Following that, the Comparative Table is used to calculate the gained percentage in each index based on the mean of the scores of each group using the data of the year 2021. This is done to have a better understanding of the performance of each cluster and the universities priorities for becoming greener and more successful in green-metric system. By evaluating the productivity and the efficiency of the universities, this study represents the most sustainable universities in group one (as the highly sustainable) and group two (as moderately sustainable) which have achieved the maximum grade in energy, transportation, research and instructive areas. These results also show that environmental variables (including water management, waste and infrastructure management) need to be taken into account by universities.
Environment
O. O. Obiukwu; M. N. Nwigwe; T. O. Uchechukwu; J. Azubuike; D. A. Ekpechi
Abstract
Various fiber-matrix combinations were used to create biodegradable composites using sugar cane bagasse (SCB) fiber and a polyester resin (PES) matrix. SEM, FTIR, mechanical testing, thermogravimetric analysis (TGA), and the method of soil burial were employed to assess the effects of the fiber content ...
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Various fiber-matrix combinations were used to create biodegradable composites using sugar cane bagasse (SCB) fiber and a polyester resin (PES) matrix. SEM, FTIR, mechanical testing, thermogravimetric analysis (TGA), and the method of soil burial were employed to assess the effects of the fiber content (9-54 wt%), PLA (1-5.5 wt%), starch (1-5.5 wt%), and fiber treatment on the morphology of the surface, flexural, thermal, tensile as well as biodegradable qualities of polyester/sugar cane bagasse fiber biocomposites. The outcomes demonstrated that the optimal tensile strength of biocomposites, impact, and Flexural capabilities were attained by the 37 wt% treated sugar cane bagasse fibers. Tensile, flexural, and impact strength measurements for the 9, 18, 27, 37, 45, and 54 wt% biocomposites, respectively, ranged from 10.21 to 18.00, 21.33 to 28.12, and 12.21 to 15.67 Mpa. The results show that sugarcane bagasse-polyester composites demonstrated acceptable mechanical and multifunctional properties. This portrays the effectiveness of Sugarcane bagasse as reinforcement for Polyester matrix and its potential for eco-friendly fabrication of components.
Chemical Engineering
M. Moory Shirbani; M. Shishehsaz
Abstract
This paper introduces a novel harvester to store the electrical power, which comes from the power of external applied electrical voltage. In the last decade, most of the energy harvesters have been designed and analyzed in the form of cantilever beams. In the present article, the harvesters are analyzed ...
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This paper introduces a novel harvester to store the electrical power, which comes from the power of external applied electrical voltage. In the last decade, most of the energy harvesters have been designed and analyzed in the form of cantilever beams. In the present article, the harvesters are analyzed as a cantilever beam with the Euler-Bernoulli beam assumptions. The beam of energy harvester consists of an active Magneto-electro-elastic (MEE) layer attached to the piezoelectric layer. Assuming that the connection of these layers is perfect, the uni-morph configuration is investigated. The magneto-electro-elastic governing coupled equations of the MEE energy harvester are derived for a harmonic external applied electrical voltage in the transversal direction based on Euler-Bernoulli theory, Gaussian law, and Faraday law. These equations are solved analytically to find out the amount of harvested power and voltage. The obtained results state that by adjusting the electromechanical parameters, up to 66% of the input power and 27% of the applied voltage can be harvested. Choosing the right geometric parameters can increase the harvested power and voltages connected to the electrodes and external coil by 120.31%, 49.05% and 60.98%, respectively. Finally, the results prove the usefulness and efficiency of the dual-usage (actuator-harvester) of the new energy harvester.
Fuel Cell Technology
V. Modanloo; A. Mashayekhi; B. Akhoundi
Abstract
Bipolar plates (BPPs) play an important role in PEM fuel cells in terms of weight and cost points of view. In this paper, the manufacturing of titanium BPPs with parallel flow field was experimentally and numerically studied. In this regard, a stamping die with a parallel pattern is conducted to perform ...
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Bipolar plates (BPPs) play an important role in PEM fuel cells in terms of weight and cost points of view. In this paper, the manufacturing of titanium BPPs with parallel flow field was experimentally and numerically studied. In this regard, a stamping die with a parallel pattern is conducted to perform the experiments. Then, the process was modeled via the finite element (FE) simulation. By comparing simulation and experiment results, it was found that the results are in good agreement and hereupon, the accuracy of the FE model was verified. To evaluate the sheet formability, a set of FE experiments was designed through the response surface methodology (RSM). The die clearance, forming velocity, and friction coefficient were considered input parameters, and the maximum thickness reduction (MTR) of the sheet was assumed to be the output. The results revealed that a lower friction coefficient causes an increase in thickness reduction and finally tearing in the formed BPPs. Moreover, changing the forming velocity has no remarkable influence on the MTR. Afterward, an Adaptive Neuro-Fuzzy Inference System (ANFIS) was trained for predicting the output of the MTR with the three mentioned inputs.
Chemical Engineering
A. Kamani; I. Mirzaee; N. Pourmahmoud
Abstract
In this study, first-law, second-law, and exergo-economic investigations are accomplished to recover the waste heat of a two-shaft turbofan engine applying a supercritical carbon dioxide Brayton cycle. The efficacy of different operating parameters including the inlet temperature of the turbine, the ...
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In this study, first-law, second-law, and exergo-economic investigations are accomplished to recover the waste heat of a two-shaft turbofan engine applying a supercritical carbon dioxide Brayton cycle. The efficacy of different operating parameters including the inlet temperature of the turbine, the pressure ratio of the compressor, and Mach number on the performance of the proposed system in terms of energy and exergy performance, exergy destruction rate, and annual levelized cost of investment have been examined. The results indicate that the energy performance of the cycle is specified as 42.94%, the second-law performance of the cycle is calculated as 85.88% and the whole power generation amount of the system is achieved to be 9806 kW. Also, the results display that among the various components of the proposed system, the maximum amount of exergy destruction occurred in the low-pressure compressor, the fan, and the mixer. It is found that by increasing the inlet temperature of the high-pressure turbine, the first-law efficiency and the second-law efficiency of the proposed cycle decrease while the total cost rate and exergy destruction rate increase. Moreover, it is inferred that the thermodynamic efficiency of the system rises when the pressure ratio of the compressor and Mach number increase. The outcomes also demonstrate that concerning the capital costs and exergy destruction costs of components, the highest amount is obtained for high-pressure turbine and recuperator, which are 326.3 $/h and 358.4 $/h, respectively.
Energy
M. Maghsoudizadeh; M. Ameri; E. Jahanshahi Javaran; A. MotamedSadr; A. A. Feili Monfared
Abstract
In recent years, the use of renewable energy sources and investigation on renewable energy have significantly grown. In this research, parabolic trough and linear Fresnel collectors, which are widely used in the field of solar energy, have been investigated from the point of view of exergy. First, the ...
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In recent years, the use of renewable energy sources and investigation on renewable energy have significantly grown. In this research, parabolic trough and linear Fresnel collectors, which are widely used in the field of solar energy, have been investigated from the point of view of exergy. First, the energy balance equations for different components of the collector were solved using numerical methods and the temperature distribution in each component of the collector was obtained. Then the values of exergy destruction in each component of the system were calculated. The comparison of the results obtained in the present work with the results of the previous research showed a good agreement. The results showed that the exergy efficiency in the parabolic trough collector is approximately 1.5 times that of the linear Fresnel reflector. Also, changes in exergy efficiency, exergy destruction of the whole collector, output exergy cost and CO2 emission with increasing solar radiation intensity and fluid mass flow rate for both collectors have been compared and investigated.
T. Salehi; D. Yousefi Kebria
Abstract
The present study focused on the synergistic effects bioremediation of phenol in aqueous solution using combination of anaerobic mixed culture and Granular Activated Carbon (GAC) as a biological GAC (BGAC). Meanwhile, the effect of contact time and various phenol concentrations on adsorption and ...
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The present study focused on the synergistic effects bioremediation of phenol in aqueous solution using combination of anaerobic mixed culture and Granular Activated Carbon (GAC) as a biological GAC (BGAC). Meanwhile, the effect of contact time and various phenol concentrations on adsorption and biosorption process investigated. The phenol concentration was analyzed using UV/Vis spectrophotometer. The morphology and structure of two adsorbents (GAC and BGAC) were characterized by FESEM and BET specific surface area analysis. The batch experiments using mixed bacterial culture, isolated from wood and paper factory wastewater, were adapted to high concentrations of phenol and employed in order to evaluate the tolerance and biosorption capability of microorganisms for phenol biodegradation. The synergetic effect of phenol removal using combination of GAC with an anaerobic biofilm indicated that the removal efficiency for concentration of 700, 800, and 1000 mg/l at initial stages increased to 4, 10, and 12%, respectively and while by increment of the retention time did not shown significant impact on the removal efficiency. These results conducted both desorption of adsorbates due to biotransformation in the aqueous solution and direct assimilation of adsorbates on GAC by the microorganism’s biofilm. The adsorption data were fitted with pseudo-first-order and pseudo-second-order models and it was found that the pseudo-second-order model explains the adsorption kinetics more efficiently. The compatibility of the Freundlich and Langmuir adsorption models to equilibrium data were investigated. In fact, the Langmuir isotherm was found to be the best fitting isotherm.
