M. Hezarjaribi; G. Bakeri; M. Sillanpaa; M. J. Chaichi; S. Akbari; A. Rahimpour
Abstract
The significance of toxic metals pollution treatment has become incrementally manifested as an important environmental issues in the recent years due to the urgent need to access healthy water and increase of the anthropogenic activities in water contamination. For efficient treatment of water contaminants, ...
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The significance of toxic metals pollution treatment has become incrementally manifested as an important environmental issues in the recent years due to the urgent need to access healthy water and increase of the anthropogenic activities in water contamination. For efficient treatment of water contaminants, the selective and novel materials are always welcomed. In this study, the hydrothermally synthesized titanate nanotubes (TNT) were modified by the mercaptosilane modifier for the removal of Cu(II) and Ni(II) toxic contaminants. The modified TNT adsorbent (TNT/Sil) was characterized in terms of the physicochemical aspects and then, the experiments for capturing metal cations were performed in batch mode. The modified adsorbent presented more affinity for the removal of Cu(II) than Ni(II).Theresults demonstrated thatthe experimental data were highly fitted to the Freundlich isotherm model and the maximum uptake capacities for Cu(II) and Ni(II) were found to be 53.77 and 45.29 mg g-1, respectively. In addition, endothermic nature of the adsorption process was predicted by the thermodynamic study as well as the pseudo-second order model that was corresponded to the kinetic data. Considering these achievements and due to the surface hydroxyl and thiol functional groups, TNT/Sil adsorbent could be effective and promising material in the purification of wastewaters, contaminated with toxic metal cations.
N. Norouzi; M. Fani
Abstract
The pandemic scenario caused by Covid-19 generated negative impacts. Covid-19 has made it clear that our daily lives depend to a high degree on access to energy. Therefore, now more than ever, it is necessary to promote new activities such as local food production, but also local energy capture. This ...
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The pandemic scenario caused by Covid-19 generated negative impacts. Covid-19 has made it clear that our daily lives depend to a high degree on access to energy. Therefore, now more than ever, it is necessary to promote new activities such as local food production, but also local energy capture. This article is an attempt to expose and quantify the benefits of a renewable energy transition in Ecuador post Covid-19 and post-oil. The generation, consumption, and reserves of oil in Ecuador were characterized, and the concept of energy transition was applied to evaluate the possibilities of integration of renewables, the progressive exit of thermal power plants, and future energy strategies. The year 2015 was taken as a basis and it was determined that energy use was 154.0 TWh / year, which corresponds to an end-user of approximately 147 TWh / year. The objective was to reduce this end-use demand to 80.0 TWh/year by 2055 through the integration of renewables and energy efficiency, for which 5 transition phases were planned until a 100% renewable system was obtained. It is concluded that the energy transition in Ecuador is technically possible and economically viable, without giving up the energy well-being that we currently enjoy. However, results show that even 100% renewable is not enough to face climate change.
Energy
N. Tayari; M. Nikpour
Abstract
New designing techniques have been used recently in design phases of buildings to adapt human thermal comfort. Due to wide range of energy consumption within a building, it is impossible to make a proper decision about the impact of different energy efficiency strategies without simulation tools. Architects ...
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New designing techniques have been used recently in design phases of buildings to adapt human thermal comfort. Due to wide range of energy consumption within a building, it is impossible to make a proper decision about the impact of different energy efficiency strategies without simulation tools. Architects need to understand the accuracy and precision of simulation software to use them as valuable tools to predict energy consumption. This research aims to investigate the validity of DesignBuilder simulation software by using the actual traditional house in terms of heat gain. In this study, the comparative method was used to determine the differences in heat gain in a traditional courtyard house in Kerman that was simulated using DesignBuilder software and measured experimentally. This study also reveals that the difference between simulation results and empirical measurement is not more than 10%. It can be concluded that DesignBuilder has enough validity to calculate the amount of heat gain in the rooms adjacent to courtyards.
Energy
F. Chabane; N. Moummi; C. Toumi; S. Boultif; A. Hecini
Abstract
This study aimed to compare global solar radiation on the horizontal area between two models of Chabane Foued and M.Capderou. The model of Chabane has been interested in pollution factors such as TL (turbidity), BE (Angstraon), and the chemical components of the air such as WV, O3, CH4, CO, CO2, and ...
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This study aimed to compare global solar radiation on the horizontal area between two models of Chabane Foued and M.Capderou. The model of Chabane has been interested in pollution factors such as TL (turbidity), BE (Angstraon), and the chemical components of the air such as WV, O3, CH4, CO, CO2, and the especial part the new pollution factor such as hbeam, kbeam, and kdiffuse, which all influenced onto solar radiation, and the model of Capderou has been used the atmospheric disturbance to calculate the direct and diffuse components of radiation received on a plane, while the constituents of the atmosphere (absorption and diffusion) can be expressed by disturbance factors, which is very necessary to determine irradiation In the clear sky. The results reveal a significant difference between the two models with approximated curves. The difference between the models probably returns to the nature of the geographic site which the authors used and injected into the models.
S. Talesh Amiri; R. Shafaghat; O. Jahanian; A. H. Fakhari
Abstract
To better homogenize the mixture of fuel and air in the combustion chamber and to enhance the controllability of ignition timing in Reactivity Controlled Compression Ignition (RCCI) engines, controlling the start of injection (SOI) timing can be essential. By changing the SOI timing, at some specific ...
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To better homogenize the mixture of fuel and air in the combustion chamber and to enhance the controllability of ignition timing in Reactivity Controlled Compression Ignition (RCCI) engines, controlling the start of injection (SOI) timing can be essential. By changing the SOI timing, at some specific crank angles (CAs), the fuel can impact the edge of the piston bowl and create some difficulties. In this research, initially, efforts are made to recognize the range of SOI timing in which this collision process takes place (in the range of 44-54° bTDC), then, performance and the emission levels of the engine were evaluated in the beginning and end of this interval. The findings suggest that the nitrogen oxides emissions and the maximum in-cylinder mean pressure are higher in SOI of 44° bTDC, as compared to those in the SOI timing of 54°bTDC, although the latter has higher ignition delay and unburnt hydrocarbon (UHC) emission. Moreover, some evaluations were carried out to examine how the temperature of the fuel-air mixture can affect the performance of the engine in this specific range. It was found that as the IVC temperature increases, it rises the indicated mean effective pressure (IMEP), in-cylinder pressure, and NOx emission.
Energy
S. A. Gandjalikhan Nassab
Abstract
This paper presents an original concept of using high flexible flapping vortex generator in a heat sink for airside heat transfer augmentation. The proposed thin winglet, made with an elastic sheet, is responsible for increasing the cooling rate and mixing quality performance in laminar convection airflow. ...
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This paper presents an original concept of using high flexible flapping vortex generator in a heat sink for airside heat transfer augmentation. The proposed thin winglet, made with an elastic sheet, is responsible for increasing the cooling rate and mixing quality performance in laminar convection airflow. This study focuses on the excessive bending of the flapping winglet and reducing its blockage effect and pressure drop. This novel concept is demonstrated using a numerical simulation of the flow field with a coupled Fluid-Solid-Interaction technique in transient conditions. The continuity, momentum, and energy equations for forced convection airflow are solved by the finite element method using the COMSOL Multi-physics. Numerical results reveal high amplitude for the flapping vortex generator while under a large deformation and bending. This behavior leads to flow mixing with a small blockage effect due to the deformed aerodynamic shape of the winglet. The present findings show that the high flexible winglet enhances the rejected heat by 100%, with a 33% decrease in pressure drop compared to the rigid vortex generator at the same air velocity.
Energy
M. Esmaeili Shayan; M. R. Hayati
Abstract
Having kilometers of asphalt road, yet with this heat going to waste, an attempt has been made in this research to extract the road's renewable energy heat. The purpose of the experiment is to compare the energy and exergy efficiency of various materials of asphalt solar water heaters (ASWH), as well ...
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Having kilometers of asphalt road, yet with this heat going to waste, an attempt has been made in this research to extract the road's renewable energy heat. The purpose of the experiment is to compare the energy and exergy efficiency of various materials of asphalt solar water heaters (ASWH), as well as heat transmission through the water tube and how friction affects exergy destruction. The water flow rate of one ASWH was 0.01 kg/s, while that of the other was 0.02 kg/s. Each ASWH has an area of 0.5 square meters. The copper tube is buried 10 mm deep in the asphalt. 15 degrees is the angle of inclination. The results indicate that the energy and exergy efficiencies are reasonably high for the water flow rate of 0.02 kg/s. Depending on the water flow rate, asphalt temperature, and sunlight intensity, the energy and exergy efficiencies changed from 32% to 65% and 5.8% to 16%, respectively. The water flow rate is an essential parameter for estimating the internal convective heat transfer coefficient and Reynolds number in order to calculate the friction factor in the copper tube based on internal convection heat transfer. In contrast, the friction factor is a consequence of the pressure loss and exergy degradation induced by friction.
V. Ferreira; S. P. D. Alves; C. C. Sousa; G. R. V. Pinheiro; L. C. R. S. Teixeira; A. L. de Sá Salomão
Abstract
Chlorella vulgaris is one of the most common and characterized algae genus with several applications, including carbon sequestration, biofuel, food production and wastewater treatment. Chlorella sp. are considered suitable to be used as model organisms in space research due to their cultivation flexibility. ...
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Chlorella vulgaris is one of the most common and characterized algae genus with several applications, including carbon sequestration, biofuel, food production and wastewater treatment. Chlorella sp. are considered suitable to be used as model organisms in space research due to their cultivation flexibility. Many studies have been carried out to ensure better conditions for supporting human life on long-term missions in deep space or on planetary surfaces, minimizing the need for resupplies. Regardless of the resilience of the genus Chlorella to space conditions has already been demonstrated, model organisms are useful in the improvement of new technologies. This research aimed to develop the culture conditions and a monitoring system for C. vulgaris, under microgravity, using an image capture device for CubeSats. The image acquisition system consisted of a digital microscope, with remote access, a Single Board Computer, a monitoring computer, and an image processing algorithm. Three microalgae colonies, under laboratory conditions, were evaluated in real time (every 30 minutes) using the size of the colonies as a parameter for evaluating growth rates. The highest microalgae biomass production for the three monitored colonies (C1-C3) was: increase of 28% for C1 after 90 h; 21% for C2 after 84 h; and 36% for C3 after 120 h. The results indicated that the system was able to monitor the growth of microalgae colonies. A specific support is being developed, which allows the installation of this image acquisition system for algae cultivation in a CubeSat, for future studies of algae growth in real microgravity conditions.
Environment
H. Esmaeil Yazdi; A. M. Salehi
Abstract
Proper acoustic design is especially important in some buildings. For example, in concert halls, one of the desirable functional features is the proper transmission of music. In this regard, an indicator that can effectively show the quality of the received sound is the sound intensity, which is the ...
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Proper acoustic design is especially important in some buildings. For example, in concert halls, one of the desirable functional features is the proper transmission of music. In this regard, an indicator that can effectively show the quality of the received sound is the sound intensity, which is the purpose of this study is a way to optimize this indicator. Among the most effective variables that will affect the intensity of the received sound and also the important characteristics of the sound source are the frequency and octave of the sound, as well as the distance between the sound source and the receiver. In this research, a new method was proposed to investigate the effect of these three variables on the received sound intensity. In this regard, ODEON software, one of the most powerful software in acoustic design, was used and data analyses were implemented. Then, using full factorial method (one of the experimental design methods), targeted scenarios based on three independent variables were identified and by using the results of simulated scenarios, the linear relationship between the dependent variable (sound intensity) and independent variables (frequency, octave and distance) were developed. Using this linear relationship, it was found that the octave of sound has the greatest effect on sound intensity, and sound frequency and distance from the sound source were inversely related to the sound intensity.
A. Jain; P. Ekambaram; S. S. Thipse
Abstract
Small Diesel engines pose a very tough challenge of simultaneously meeting NOx and particulate matter (PM) emissions, without hampering performance and fuel consumption. Frequent revision in small diesel engines pose a very tough challenge of simultaneously meeting NOx and PM emissions, without hampering ...
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Small Diesel engines pose a very tough challenge of simultaneously meeting NOx and particulate matter (PM) emissions, without hampering performance and fuel consumption. Frequent revision in small diesel engines pose a very tough challenge of simultaneously meeting NOx and PM emissions, without hampering performance and fuel consumption. Frequent revision in emission norms for small diesel engines makes it further difficult, as they need to be upgraded in design and for combustion. These small, low-capacity engines are predominantly used in specific regions/countries where cost plays a major role and hence these engines lack a clear emission reduction strategy. It is required to develop an emission reduction strategy considering available technologies and cost implications. Current research work aims to develop a cost-effective emission reduction strategy by modifying the engine using conventional technologies. The present work is an experimental study of the effect of cylinder head Swirl, static injection timing (SIT), intake valve opening (IVO), and Exhaust gas recirculation (EGR) on a 0.4 l single-cylinder diesel engine's performance and emission. Baseline vehicle has HC+NOx and PM emission levels are 0.61 g/kM and 0.04 g/KM, respectively; which is higher considering existing and upcoming emission norms. The lower Swirl cylinder head, advanced IVO timings with retarded injection timings shows an 18% reduction in NOx emission with a 3% improvement in performance at the engine dynamometer. Different EGR rates were also studied and effects were analyzed on emission and fuel consumption and emissions. EGR rate of 25% with advanced IVO of 16° with SIT of 5° and 1.9 Swirl cylinder head had shown 48% improvement in HC+NOx emissions, 20% improvement in PM emission, and 11% improvement on CO emissions at the Chassis dynamometer.
Energy
A. Yousefi; R. Shafaghat; M. Beykani; A. Aghajani Afghan; S. T. Seyyed Mostafa
Abstract
Surface piercing propellers are special supercavitation propellers operating at free surface. These propellers are designed to have the best performance at the highest speed. The geometric parameters of the number of blades and the pitch ratio will significantly impact the critical advance coefficient ...
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Surface piercing propellers are special supercavitation propellers operating at free surface. These propellers are designed to have the best performance at the highest speed. The geometric parameters of the number of blades and the pitch ratio will significantly impact the critical advance coefficient range, ventilation and consequently the hydrodynamic performance of the propeller. Therefore, in this paper, the effect of two crucial parameters of pitch ratio and number of blades were experimentally studied in free surface water tunnel. After calibration and evaluation of uncertainty, two 5-bladed propellers with same section profile and pitch ratio of 1.5 and 1.4 used to investigate effect of pitch ratio. The results of two 5-blade and 6-blade propellers with same section profile and pitch ratio of 1.4 were compared. The immersion ratio was 40%, and the shaft inclination angle was zero. Results showed that increasing the pitch ratio increased the thrust and torque coefficients by 30%; while increasing the critical advance coefficient. Consequently that has led to the development of a full ventilation range and improved hydrodynamic performance of the propeller. In addition, by increasing the number of blades, at values greater than the critical advance coefficient, the thrust and torque coefficients were increased by 10%. However, the critical advanced coefficient changes were negligible. Comparing the results in the three-dimensional contours showed that with the change in the number of blades, by increasing the pitch ratio, the critical advance coefficient increased; which led to a further increase in efficiency.
Energy
S. Abdoli Naser; F. Haghparast; M. Singery; H. Sattari Sarbangholi
Abstract
Most of today's buildings, due to improper imitation of the architecture of buildings in other countries, are forced to use more energy to create conditions of thermal comfort. Building windows affect energy efficiency. So, the aim of this research is to be concerned with Tabriz climate; in selecting ...
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Most of today's buildings, due to improper imitation of the architecture of buildings in other countries, are forced to use more energy to create conditions of thermal comfort. Building windows affect energy efficiency. So, the aim of this research is to be concerned with Tabriz climate; in selecting the proportion and suitable glazing of the windows, in order to access the best design and execute a model to decrease energy consumption. The research approach is to utilize simulation and Design Builder software as a research tool. So, the annual gas consumed in the Building was received from the National Iranian Gas Company and a case study is modeled and after converting the unit from kWh to kg and kg to m3 and reliability of simulation results. Then, through parametric optimization, eight scenarios in designing windows and through the genetic algorithm, the glazing coating were evaluated. The simulations were performed again and the results index was examined. Eventually, based on the analysis of outputs, according to fixed area, it is more suitable to replace windows with the height of 1.5 to 1.74 meters instead of windows with the height of 1 or 1.2 meters. A window should be replaced with 2, 3, 4 or 5 windows with the same fixed area. I is desired to superseded triple-glazed glazing with low-emissivity filled with argon gas with clear double-glazed glazing filled with air to reduce energy consumption. The amount of heat losses for the window height of 1 to 1.5m, from one window to five windows and for the clear double-glazed glazing filled with air were 2.04%, 11.11%,. and 45.36%, respectively.
M. Helmi; A. Hemmati; K. Tahvildari
Abstract
The transesterification of Amygdalus scoparia oil to biodiesel was performed and examined through the electrolysis method in the presence of KOH/Al2O3 as a heterogeneous catalyst at room temperature. A KOH/Al2O3 as solid base catalyst was prepared through the impregnation of Al2O3 with KOH solution (concentration ...
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The transesterification of Amygdalus scoparia oil to biodiesel was performed and examined through the electrolysis method in the presence of KOH/Al2O3 as a heterogeneous catalyst at room temperature. A KOH/Al2O3 as solid base catalyst was prepared through the impregnation of Al2O3 with KOH solution (concentration of 25g in 100 mL deionized water). The catalyst was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The transesterification key variables such as reaction time, methanol to oil molar ratio, and catalyst weight were optimized by applying the central composite design (CCD) approach. The maximum yield of 94% was obtained at the methanol to oil ratio of 10:1, catalyst weight of 1.6 wt/v%, voltage of 10 V, a reaction time of 2.30 h, 10 wt% acetone at room temperature (25 ᵒC). The characterizations of Amygdalus scoparia oil and biodiesel were specified using a gas chromatography-mass spectrometry (GC-MS) and Fourier-transform infrared spectroscopy (FTIR) analyses.
Environment
E. O. Dada; F. A. Oke; Y. O. Balogun
Abstract
Earthworms and crabs are known to influence the physicochemical state of their respective soil habitats through their bioturbation actions. While earthworm-bioturbated soils have been well documented to positively affect plant growth, not much is known about the effects of crab-bioturbated soil on plant ...
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Earthworms and crabs are known to influence the physicochemical state of their respective soil habitats through their bioturbation actions. While earthworm-bioturbated soils have been well documented to positively affect plant growth, not much is known about the effects of crab-bioturbated soil on plant growth. In this study, we compared the growth performance of four varieties of Phaseolus vulgaris (bean) seedlings in earthworm-bioturbated soil, crab-bioturbated soil, and unbioturbated soil collected within the same proximity of a wetland habitat. Seeds of Phaseolus vulgaris were planted in replicates in each soil type, and allowed to grow for 15 days. Physical growth was measured using a metre rule. Biochemical growth parameters were measured using standard procedures. The differences in stipule length of bean seedlings grown in all the soil types were generally not significant (p > 0.05). However, seedlings grown in earthworm-bioturbated soil and crab-boturbated soil recorded significantly higher (p < 0.05) stipule weight, relative to those grown in unbioturbated soil. Bean seedlings grown in earthworm-bioturbated soil recorded the highest and significant (p < 0.01) concentrations of chlorophyll, total sugar, starch, nitrogen, and crude protein, relative to those grown in crab-bioturbated and unbioturbated soils. This was followed by seedlings grown in crab-bioturbated soil which recorded significantly higher (p < 0.01) concentrations of these biochemical parameters, relative to those grown in unbioturbated soil. The significantly higher biochemical and marginally better physiological growth recorded for seedlings in bioturbated soils indicate that earthworms and crabs both contribute significantly to wetland productivity, through their bioturbatiion activities.
Energy
N. Tayari; M. Nikpour
Abstract
One of the crucial issues in early stages of designing process of a building is a lack of architects’ knowledge about the energy consumption in different forms of building with different proportions, especially in central courtyard forms. The purpose of this research is to investigate the effectiveness ...
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One of the crucial issues in early stages of designing process of a building is a lack of architects’ knowledge about the energy consumption in different forms of building with different proportions, especially in central courtyard forms. The purpose of this research is to investigate the effectiveness of the ratio of perimeter to the height of the courtyard (R1) and the ratio of width to length of the courtyard (R2) on energy consumption. In the first step of this research, different proportions of central courtyard with different R1 and R2 were simulated in design builder software. Then, multi linear regression was used to find out the effect of different proportions (R1 and R2) on energy consumption through SPSS software. Finally, the effect of R1 and R 2 ratio on energy consumption was validated through investigating six existing central courtyard forms. The result demonstrated that the effective coefficient of the R1 and R2 ratio on energy consumption were -25.41 and 62.69 respectively. Findings of this research help architects to achieve relative acknowledge about the energy consumption of different proportions of the courtyard forms for creating more energy efficient forms.
I. Reeder; W. Coulet; D. Miko; J. Thomas; G. Hopkins
Abstract
An innovative method applicable to saltmarsh habitat restoration using dredged sediment was tested. Biodegradable wooden sluice boxes were placed in eroded “pits” or pools in the damaged saltmarsh and dredged sediment was pumped to fill these pits up to the level suitable for saltmarsh flora ...
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An innovative method applicable to saltmarsh habitat restoration using dredged sediment was tested. Biodegradable wooden sluice boxes were placed in eroded “pits” or pools in the damaged saltmarsh and dredged sediment was pumped to fill these pits up to the level suitable for saltmarsh flora colonisation. The sluice boxes were used to carefully control volumes and dewatering of dredged material to maximise the resultant fill level. Sediment was left to settle during periods of high tide and water was prevented from entering and mixing the deposited sludge. During low tide, the supernatant was drained off, enabling more material to be deposited. This technique helped develop a layer of substrate for pioneer halophytes to colonise, without loss of material through natural entrainment and deposition back into source sites. Increases in colonisation, consolidation, shear strength and bulk density of the newly placed sediment proved the suitability of this technique for habitat restoration.
Environment
V. Montazeri; B. ZareNezhad; A. Ghazi
Abstract
The nanofluid-based gas hydrate formation process employing copper oxide (CuO) nanoparticles have been experimentally investigated in this work. Different concentrations of nanofluids are injected into the reactor at the operating condition of 29 bar, 274.15 K, and impeller speed of 100 rpm. It was observed ...
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The nanofluid-based gas hydrate formation process employing copper oxide (CuO) nanoparticles have been experimentally investigated in this work. Different concentrations of nanofluids are injected into the reactor at the operating condition of 29 bar, 274.15 K, and impeller speed of 100 rpm. It was observed that the kinetics of the carbon dioxide hydrate formation process was greatly affected by the nanoparticles. The remarkable point was that at a very low concentration of 20 ppm, a considerable improvement on the carbon dioxide hydrate formation kinetic without using any surfactant was obtained. At the concentration of 20 ppm, the values of the initial rate of hydrate formation, growth time, and induction time were 0.0495, 194.5, and 4.4 min, respectively, which these results can be of great importance for the use of carbon dioxide hydrate in various industries. The results indicated that the kinetics of gas hydrate formation was also severely influenced by the impeller speed and initial gas pressure. The rate of CO2 captured in the hydrate crystalline lattice is also modeled by the first-order kinetic model. It was seen that this model can be used to predict the rate of hydrate formation with considerable accuracy.
Energy
A. Amini; N. M. Nouri
Abstract
The Surface-Piercing propeller blades move in and out of the water with each rotation to reduce the immersion depth from the free surface to the shaft axis . The main challenge facing surface piercing propellers, however, is their lower efficiency at lower advance velocity, compared to other propulsion ...
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The Surface-Piercing propeller blades move in and out of the water with each rotation to reduce the immersion depth from the free surface to the shaft axis . The main challenge facing surface piercing propellers, however, is their lower efficiency at lower advance velocity, compared to other propulsion systems. To improve the performance of the propeller, an aeration mechanism was used at low advance velocities so that air was blown to the surface behind the propeller. Experimental studies were carried out on a propeller model in the Hydrotech laboratory of the Iran University of Science and Technology, and the effect of the injected air velocity ratio was evaluated at different immersion ratios. Based on the results obtained, it was concluded that an increase in the injected air velocity ratio could only promote thrust enhancement under specific conditions. For immersion ratios of 0.85 and more, as well as advance coefficients of 0.6 and more, a change in the velocity ratio of the injected air could not lead to an improvement in thrust. The best performance was identified with an immersion ratio of 0.4 and an advance coefficient of 0.4, while thrust performance at below or above of this condition declined .
S. Aghakhani; F. Haghparast; J. Gaspari
Abstract
Recent researches all across the world emphasize the threat of the increasing consumption of energy. The undeniable role of energy consumption in all stages of the life cycle of materials, including extraction, factory manufacturing, and transportation has revealed the necessity of using sustainable ...
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Recent researches all across the world emphasize the threat of the increasing consumption of energy. The undeniable role of energy consumption in all stages of the life cycle of materials, including extraction, factory manufacturing, and transportation has revealed the necessity of using sustainable methods to have lower energy consumed. The whole energy of all different steps of the life cycle is called "embodied energy" and the process of assessing this embodied energy input is called "life cycle assessment” (LCA). Despite the great importance of LCA, the quantitative test of such a hypothesis has been less of a concern for previous researchers in our country Iran, and due to the lack of organized information from industrial units, such a study has also faced the difficulties of data collection. In this regard, this paper evaluates the amount of embodied energy consumption of building materials at different stages of their life cycle. To reach this goal this research evaluates the initial energy quantitatively (including different stages). More precisely, the present study, based on life cycle assessment system, quantitatively evaluates and compares energy input in different stages of cradle to gate scope, in 3 case studies: Concrete, wood, and brick. The results finally show that per ton of concrete produced 110 (kw.h) electrical energy, 35 (ton) of gas, 170 (Mj) of human Energy, and 495 (g) of Gasoline is consumed, while these quantities for per ton of Brick are 35(kw.h), 18.2 (ton), 72 (Mj) and 250 (g) and For one ton of timber produced are 900 (Kw.h), no Gas used, 170 (Mj) and 495 (g).
Energy
H. Eskandari
Abstract
Agriculture is a system exhibiting high levels of energy consumption. Thus, energy analysis is crucial for improving the energy efficiency of agricultural systems. In this research, the input energy of an irrigated wheat production system, including seeds, machinery, fertilizer, irrigation, electricity, ...
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Agriculture is a system exhibiting high levels of energy consumption. Thus, energy analysis is crucial for improving the energy efficiency of agricultural systems. In this research, the input energy of an irrigated wheat production system, including seeds, machinery, fertilizer, irrigation, electricity, diesel fuel and human labour, were determined and thereby the net output energy, energy efficiency and energy productivity were calculated for energetic system evaluation. For reaching this goal, 110 farmers were asked to complete the questionnaires in which cultivation information such as machinery, diesel fuel, grain produced per hectare, cultivation method, the method and the duration of water supply, workers, chemical materials which were used for plant treatment. The results showed that the total input energy for producing irrigated wheat was 42,481 MJ.ha-1. Energy efficiency was achieved as 1.56, suggesting that the total output energy of the system was more than the input energy. The net output energy, indicating the rate of obtained net energy from the system, was 23,819 MJ.ha-1. Electricity and fertilizer were the inputs consuming the most energy in an irrigated wheat production system, in which 41% and 31% of the total consumed energy were devoted to electricity and fertilizer, respectively. Therefore, the appropriate management of electricity and fertilizer through advanced methods of irrigation and the precise calculation of plants’ required nutrient elements can result in the improvement of the energy efficiency of the system. Reducing seed bed preparing operations (decrease diesel fuel consumption) may also increase the energy efficiency of the wheat production system
Environment
E. Samadpour Shahrak; H. Sattari Sarbangholi; M. S. Moosavi
Abstract
One of the crucial factors for the presence of more people outdoors is to create comfortable conditions. This issue is significant for the elderly due to the different physical conditions. The purpose of this study is to improve the micro-climatic condition around residential complexes considering the ...
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One of the crucial factors for the presence of more people outdoors is to create comfortable conditions. This issue is significant for the elderly due to the different physical conditions. The purpose of this study is to improve the micro-climatic condition around residential complexes considering the elderly in a linear type. For this purpose, two physical indicators, the ratio of the height of buildings to their distance from each other (H/D) and the orientation of them towards the street, were investigated. Regarding H/D, ratios of 0.5, 1, 1.5, and 2, and about the orientation factor, angles of 135° to 200° were examined. This study was conducted outdoors around residential complexes in Iran, Tabriz, with a cold semi-arid climate. Envi-met software model 4.4.5 was used for the simulation. The days June 22 and December 22, 2020 were selected as one of the hottest and coldest day of the year. Two indexes of the Predicted Mean Vote (PMV) and the Universal Thermal Climate Index (UTCI) were examined as essential thermal comfort indexes. Also, for validation, local and field data in six days (21, 22, 23 June in summer and 21, 22, 23 December in winter) were extracted and compared with the data of the software. The results display, the ratio of H/D=1.5 and the angles of 135° and 145° were the most suitable comfort conditions.
Energy
S. Prem Kumar; G. Kumar
Abstract
In solar drying, the moisture content of a product is reduced through the use of sunlight. Solar drying is practiced since civilization for the drying of crops. The dried crop has a longer shelf life and requires less storage space. For crop drying, hot air is required in the moderate temperature range ...
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In solar drying, the moisture content of a product is reduced through the use of sunlight. Solar drying is practiced since civilization for the drying of crops. The dried crop has a longer shelf life and requires less storage space. For crop drying, hot air is required in the moderate temperature range of 40 to 75℃. Solar dryer makes it possible to obtain better product quality. Over the past 20 years, numerous experimental projects have been carried out in the field of solar dryers. Most conventional dryers are not able to operate continuously during the off sunshine time. However, attempts were made to develop uninterrupted solar drying systems by incorporating an energy storage facility and a hybrid mode of operation. Sensible and latent heat storage methods are widely used to store solar energy. Heat storage materials store energy in the form of heat during sunshine and release it whenever it is required. Biogas backup, Chemical heat pump, Photo Voltaic, and Fluidized bed methods were integrated with solar dryers for uninterrupted operation. In this article, the discussion is made about different dryers. Also, the challenges and scope in the area of the solar dryer are highlighted.
T. O. Yahaya; E. O. Oladele; O. R. Abiola; O. Ologe; A. Abdulazeez
Abstract
The Bariga section of Lagos lagoon is famous in Lagos for fishing activities. However, the safety of edible fishes sold in the place has not been evaluated for a long time. This study determined the safety of Clarias gariepinus (African catfish), which is the most frequently patronized fish species in ...
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The Bariga section of Lagos lagoon is famous in Lagos for fishing activities. However, the safety of edible fishes sold in the place has not been evaluated for a long time. This study determined the safety of Clarias gariepinus (African catfish), which is the most frequently patronized fish species in the area. Samples of the fish and soil sediments obtained during rainy and dry seasons were subjected to atomic absorption spectroscopy to determine the levels of cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), and manganese (Mn). Afterward, the daily intake (DI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risks (CR) of the heavy metals were calculated. The results showed that the levels of Cd and Pb in the fish and soil sediments were above the world health organization (WHO) permissible limits, while Zn, Cu, and Mn were normal. The DI of the heavy metals, as well as the THQ and HI, were normal. However, the CR of Cd and Pb were above the recommended limits. The heads of the fishes contained the highest concentrations of the heavy metals, DI, THQ, HI, and CR. Among the heavy metals, Cd had the highest CR. There was no significant (p > 0.05) seasonal variation in the accumulations of the heavy metals in the soil sediments. Overall, the results showed that the fish may predispose consumers to health hazards. Consequently, there is a need for heavy metal pollution control in the lagoon, to safeguard the health of fish consumers.
Energy
R. Aghagolzadeh Silakhor; O. Jahanian; B. Alizadeh Kharkeshi
Abstract
Using cogeneration systems is a great way to tackle fossil fuel consumption problems. This paper introduces a Combined Cooling Heating Power (CCHP) system to recover the waste heat of an RK215 heavy diesel engine as a prime mover. Therefore the CCHP system consists of Internal Combustion Engine (RK215), ...
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Using cogeneration systems is a great way to tackle fossil fuel consumption problems. This paper introduces a Combined Cooling Heating Power (CCHP) system to recover the waste heat of an RK215 heavy diesel engine as a prime mover. Therefore the CCHP system consists of Internal Combustion Engine (RK215), a heat storage tank, and an absorption chiller. Also, the system has been studied in four modes: CCHP, CHP, CCP, and single generation. The waste heat ratio has changed due to a y factor, and the effect of this different parameter, such as the start of fuel injection and exhaust gas heat, on the system's efficiency by considering first and second laws of thermodynamic in different operating modes has been investigated. The system's highest energy and exergy efficiency in CCHP mode is equal to 50.46 and 30.8%, respectively. According to the result, as the CCHPs cooling load to the absorption chiller increases, the performance also rises. Also, the system’s carbon dioxide emissions reduction has been studied. The results showed that using different modes for waste heat recovery can reduce carbon dioxide by up to 30% approximately for different modes. Also, the fuel energy saving ratio (FESR) has been investigated, and the results showed that systems in CCHP, CHP, and CCP modes could have FESR approximately equal to 21%.
N. Norouzi; M. Fani
Abstract
Coal is one of the main primary energy resources in South Africa. This energy carrier is also one of the primary indicators in the energy security of the country. This paper is aimed to examine coal consumption and environmental sustainability in South Africa by examining the role of financial development ...
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Coal is one of the main primary energy resources in South Africa. This energy carrier is also one of the primary indicators in the energy security of the country. This paper is aimed to examine coal consumption and environmental sustainability in South Africa by examining the role of financial development and globalization phenomena using a data set gathered from 1980 to 2017. Based on this paper’s scope, ARDL Bounds, Bavaria, and the combined Hank, FMOLS, DOLS, and frequency domain tests of the causality test are used. Bayer and Hank integration tests and ARDL constraints (with Kripfganz and Schneider’s approximations) showed a common integration between this set. Findings based on ARDL short-term and long-term estimates present that economic development improves environment preservation, while economic growth and coal consumption increased environmental degradation. The frequency-domain causality test results showed that coal consumption and financial development significantly determine the environment’s stability at different frequencies.
