S. Mohite; S. Kumar; S. Maji; A. Pal
Abstract
Karanja and linseed are the potential non-edible oil crops which can be used for the biodiesel production. The main objective of this study is to find out the feasibility of using a mixture of karanja oil and linseed oil to produce biodiesel. Karanja oil has high amount of free fatty acid in it and linseed ...
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Karanja and linseed are the potential non-edible oil crops which can be used for the biodiesel production. The main objective of this study is to find out the feasibility of using a mixture of karanja oil and linseed oil to produce biodiesel. Karanja oil has high amount of free fatty acid in it and linseed oil has low amount of free fatty acid content. Karanja biodiesel is produced by two step esterification/transesterification process which is costly, health hazardous & corrosive due to use of concentrated acids. Linseed biodiesel can be produced by alkali-base transesterfication which is much faster and gives higher yield than acid-base transesterification. A production method is developed to produce biodiesel from the mixture of karanja and linseed oil which is faster, safer and non-corrosive. The yields in the range of 68.2 to 78.9% have been achieved with varying different parameters like molar ratio, stirring time, mixture ratio and amount of catalyst. Optimum parameters are also established to achieve maximum biodiesel yield from the transesterification of a mixture of linseed and karanja oils.
W. M. Desta; A. Befkadu
Abstract
The aim of this study was to evaluate the performance of the existing water supply system of Adama Town by considering direct and indirect performance measurements. The paper also investigates the application of technical performance index to evaluate the operational performance of the water distribution ...
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The aim of this study was to evaluate the performance of the existing water supply system of Adama Town by considering direct and indirect performance measurements. The paper also investigates the application of technical performance index to evaluate the operational performance of the water distribution system and to easily identify the critical areas in the network. The evaluation carried out based on WaterNetGen tools an extension of EPANET to attain direct performance measurement and Minitab16 software to analyze primary data to achieved indirect performance measurement. Based on water tap flows result, most of the residences got water at night time and were not satisfied with the town water supply services. The greatest minimum slack pressure and velocity occurred in a small area of the network, and the global technical performance index of pressure and velocity were 35.75% and 46.19%, respectively.
A. Khanjari; E. Mahmoodi; A. Sarreshtehdari; M. Kordi
Abstract
In this paper, the effect of stall delay on distribution of normal forces in different sections of rotor are studied by an enhanced version of the blade element momentum theory (BEM), based on the 3D correction Chaviaropoulos and Hansen mode. This model is computed at wind speed of 24m/s under the yaw ...
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In this paper, the effect of stall delay on distribution of normal forces in different sections of rotor are studied by an enhanced version of the blade element momentum theory (BEM), based on the 3D correction Chaviaropoulos and Hansen mode. This model is computed at wind speed of 24m/s under the yaw angle 15◦. It is found that the BEM calculation on the outer (the radial distance more than 35% spanwies) spanwise is more trustable than inner spanwise. At 60, 82 and 92% spans, the 3D correction does not affect the output result and stall does not occur. Relative velocity rose dramatically at 25 and 35% spans, consequently angle of attack increased too particularly between azimuth angles from 270◦ up to 90◦. In this regions, stall phenomena are happened. Also it is found that the 3D correction has the maximum effect on 35 and 25% spans. The maximum improvement is 99.57% at 35% section and the azimuth angle 121◦.
Chemical Engineering
M. Ibrahim Abduljabbar; H. Ghafouri Taleghani; I. Esmaili Paeen Afrakoti
Abstract
In this research, gas sweetening process of the Iraq Majnoon refinery plant and its optimization scenarios were investigated using ASPEN HYSYS 8.4 and genetic algorithm optimization. First, values of optimization parameters such as the values of the population, generations and crossover for single and ...
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In this research, gas sweetening process of the Iraq Majnoon refinery plant and its optimization scenarios were investigated using ASPEN HYSYS 8.4 and genetic algorithm optimization. First, values of optimization parameters such as the values of the population, generations and crossover for single and multi-objective optimizations were obtained. The effect of temperature and molar flow of feed gas and make-up water on concentration of CO2 and H2S in the sweet gas were studied. The result showed that with increasing the temperature and molar flow of feed gas, the concentration of CO2 and H2S in the sweet gas was increased. The single and multi-objectives’ optimizations of process were carried out with minimizing the concentration of CO2 and H2S, minimizing the consumed energy of stripper and overall consumed energy of plant including energy of stripper and cooler. It was observed that for optimization of concentration of CO2 and H2S, mole fraction of CO2 and H2S decreased to minimum amounts of 5.52 e-4 and 6.84 e-9 between optimization data sets. Also, it was found that with increasing the number of objective functions of the optimization, the ability of the algorithm to reduce the amount of the objective functions decreases, because genetic algorithm should consider more constraints with increasing the number of objective functions. The novelty of this research was a comprehensive study of gas sweetening process optimization with single to four objectives.
M. Firoozzadeh; A. H. Shiravi; M. Shafiee
Abstract
Paper mill producing several type papers has a wastewater treatment plant with an aerated lagoon system to remove their pollutants. But the removal efficiency of this system is still low so that the effluent is still not complying with the Indonesian of effluent quality standards yet. It needs pre-treatment ...
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Paper mill producing several type papers has a wastewater treatment plant with an aerated lagoon system to remove their pollutants. But the removal efficiency of this system is still low so that the effluent is still not complying with the Indonesian of effluent quality standards yet. It needs pre-treatment plant before aerated lagoon. In an effort to improve the performance of wastewater treatment plant, study of wastewater characteristics, wastewater treatment, the establishment of treatment systems and equipment design have been carried out. After construction of pre-treatment plant, the field trial of wastewater treatment plant using wastewater originated from several type of paper produced was conducted. Result of laboratory-scale experiment showed that the paper mill needs a wastewater treatment with physical-chemical system before aerated lagoon treatment. Field trial of wastewater treatment showed that the removal of suspended solids (TSS) of 97%, COD of 88%, BOD5 of 85%, and a pH of 6.2 to 7.7 could be obtained using 5 - 10 % NaOH solution at doses of 50-240 mg/L and 0.1% cationic polyelectrolyte (PE) solution as flocculants at dose of 1.0 to 1.5 mg/L. Application of physical-chemical treatment plant can lighten the load on an aerated lagoon treatment. Effluent quality of aerated lagoon discharged into environment has met the Indonesian of effluent quality standard.
Wastewater
A. A. Rahman–Al Ezzi; S. H. Alhamdiny
Abstract
In this work, a modified internal loop airlift reactor has been designed to remove the organic pollutants in synthetic wastewater at an efficient and inexpensive treatment technique by means of a synergistic effect combining of (oxidation, stripping and adsorption). The validation of the current style ...
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In this work, a modified internal loop airlift reactor has been designed to remove the organic pollutants in synthetic wastewater at an efficient and inexpensive treatment technique by means of a synergistic effect combining of (oxidation, stripping and adsorption). The validation of the current style was experimentally examined in the treatment of synthetic Wastewater contained chloroform. The experimental testing rig was implemented at various air flow rates range (5-20) (L/min), with total variable residence period (5-60 min) with a different molar ratio of CHCl3 to H2O2 i.e. 1:10, 1:15 and 1:20. The results showed that the best molar ratio of chloroform to hydrogen peroxide was 1:20 for the air flow rate 18 L/min and extended retention period (60 min) having the uppermost results (83.3%) to remove chloroform from the contaminated effluent water. This design complements the research objectives with high efficiency through the synergy of stripping, oxidation and adsorption processes to remove contaminated chloroform from wastewater. This work contributes to a part of the solution of the environmental problems of the contaminated water before recycling, reuse or released to our safe environment.
A. Sidiki; W. Li; M. Alhousseini
Abstract
The development of solar photovoltaic faces some difficulties in West African countries; such as: high cost of kW/h produced and long duration of return on investment. To that, there are some installation and operation aspects of Photovoltaic(PV) modules. In terms of installation, the incline plays a ...
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The development of solar photovoltaic faces some difficulties in West African countries; such as: high cost of kW/h produced and long duration of return on investment. To that, there are some installation and operation aspects of Photovoltaic(PV) modules. In terms of installation, the incline plays a predominant role in the efficiency of a field photovoltaic. Indeed, the modules being fixed, it is, therefore, necessary to find the right incline so that they can capture the most solar energy every day. In terms of operation, PV modules need to be exposed to outside in order to operate under the most possibility of direct sunlight. Such equipment is therefore subjected to a natural climatic condition causing a great impact on its performance. This article deals with the influence of the operating parameters (optimal tilt and dust deposits) of PV modules in view of their improvement in West African countries such as Mali. After the choice of the cleaning by cloth and the different inclines of the modules were studied; the experiments were developed during the months of April-May-June, 2017. The results showed a reduction of PV modules from 4 to 14% of their efficiency was due to the accumulation of dirt on their capture surface. In addition, this study reveals an impressive result: a simple cleaning can save us energy about 140 FCFA/m2/month. Similarly, comparing with the outputs of the PV modules for different inclinations; it emerged that the optimal angle of inclination of the modules is slightly higher than the latitude of the study’ s place (about 15 °).
M. A. Ubaidah; S. M. H. Syed Hilmi; M. F. Mohammed Yunus; S. Tahiruddin
Abstract
Freely emitted biogas at palm oil mills has been regarded as untapped energy source nowadays, despite being recognised as major contributor to the global warming. Up till now, most of palm oil mills are still operating with the conventional anaerobic digestion systems which may not spur biogas industry ...
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Freely emitted biogas at palm oil mills has been regarded as untapped energy source nowadays, despite being recognised as major contributor to the global warming. Up till now, most of palm oil mills are still operating with the conventional anaerobic digestion systems which may not spur biogas industry to life. This study shall explore biogas production between day and night under existing mill operating conditions at KKS Bukit Benut Effluent Treatment Plant (ETP). Biogas produced during day time was 62% as compared to 38% during night time with the total methane emission of 490.3 kg/day. The methane concentration recorded at the digester tank ranged from 58.7 to 68.5%. The correlations between various factors that may influence biogas production were investigated. The finding shows that substrate feeding is the most influencial factor leading to high biogas production during day time.
B. G. Emyat
Abstract
The main aim of this study is to use waste heat for cooling effect production from cement rotary kiln shell by applying vapor absorption refrigeration system. The plant has performance to manufacture 2000 tons of clinker per day. Energy and exergy analysis has been performed to assess first and second ...
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The main aim of this study is to use waste heat for cooling effect production from cement rotary kiln shell by applying vapor absorption refrigeration system. The plant has performance to manufacture 2000 tons of clinker per day. Energy and exergy analysis has been performed to assess first and second law efficiencies and rotary kiln is used as a control volume on dry type cement plant. Result shows that about 4.3MW energy is lost from kiln shell. From the analysis, 31.13% total exergy is wasted to the surrounding in case of pre-calcining and pre-heating of raw material. The overall result for exergy analysis of kiln indicates 59.46% of irreversibility and also the first and the second law efficiency of the rotary kiln is 53.39% and 40.54%, respectively. By using convective mode of heat transfer about 11% of energy is extracted by the generator for production of cooling effect which is wasted from kiln shell. About 300kW cooling effect is produced in the evaporator by applying absorption cycle with system performance 0.67 and exergetic efficiency 87%. From heat recovery there is direct savings by reducing fuel consumption and indirect savings by decreasing environmental impact. Hence, use of waste heat results in reduction of thermal pollution and energy consumption in auxiliary equipment.
Y. Jani; M. Kriipsalu; K. Mikk Pehme; J. Burlakovs; M. Hogland; G. Denafas; William Hogland
Abstract
Landfills represent a continuous environmental threat due to the emission of different greenhouse gases, which are mainly responsible for the climate changes, and the contaminated leachate that affects the surface and ground water recipients. The circular economy approach appeared as a useful solution ...
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Landfills represent a continuous environmental threat due to the emission of different greenhouse gases, which are mainly responsible for the climate changes, and the contaminated leachate that affects the surface and ground water recipients. The circular economy approach appeared as a useful solution to reduce the depletion of the Earth’s natural resources and the environmental risk effects by considering all of the lost resources like wastes including the landfills as potential secondary resources. It is well known that characterizing the composition of landfill waste is an essential step in specifying the recycling methods. In the current research the waste composition at one of the first EU regulations-compliant sanitary landfills (the Torma landfill in Estonia) was studied. The results showed that the fine fraction (<20 mm) represented 53% of the total excavated waste materials while the waste to energy fraction (plastics, woods etc.) was the highest within the coarse fraction (>20 mm). The present work emphasized that mining landfills can be a good solution either for extracting primary raw materials like metals, as a source for recovering energy, or for acquiring landfill space.
M. Jamiati
Abstract
This paper presents a model of solar cell by using MATLAB SIMULINK. P-V, I-V and P-I characteristics were studied for various values of irradiance at constant temperature. Genetic Algorithm (GA) was used for maximum power point tracking (MPPT) of Photovoltaic (PV) system using the direct control method. ...
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This paper presents a model of solar cell by using MATLAB SIMULINK. P-V, I-V and P-I characteristics were studied for various values of irradiance at constant temperature. Genetic Algorithm (GA) was used for maximum power point tracking (MPPT) of Photovoltaic (PV) system using the direct control method. The main objective of this paper is to find out the optimal angle, which is used for the positional control of solar module and optimal power tracking. The principle of GAs is searching for the maximum of fitness function and not for the minimum of power derivation; this gives more stability and minimize oscillation of output power around the maximum power point (MPP). The main contribution of the proposed scheme is the elimination of PI control loop which normally exists to manipulate the duty cycle. Simulation results indicate that the proposed controller outperforms the others method for all type of environmental conditions.
Energy
M. Mahmoudi; H. Farzan; E. Hasan Zaim
Abstract
Asphalt materials commonly have high absorption coefficients, and their surface temperature reaches as high as 80 oC during daytime hours since their surfaces are exposed to solar radiation for long periods. Hence, asphalt pavements can easily be converted to solar air heaters (SAHs) to collect solar ...
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Asphalt materials commonly have high absorption coefficients, and their surface temperature reaches as high as 80 oC during daytime hours since their surfaces are exposed to solar radiation for long periods. Hence, asphalt pavements can easily be converted to solar air heaters (SAHs) to collect solar energy. Even though asphalt materials have low thermal conductivity, resulting in a weak convection heat exchange rate between the flowing air and asphalt surface. The current experimental study analyzes utilizing aluminum shavings as asphalt coating materials to improve SAHs’ thermal performance. To this aim, a serpentine SAH prototype was constructed, and several sensors were utilized to monitor its dynamic thermal response. Black-painted aluminum shavings were utilized as coating materials to improve the convective heat exchange rate and increase the roughness of the absorber surface. Two scenarios were considered, including the uncoated absorber plate and coated one with 0.2 kg aluminum shavings. The experiments were carried out for two air mass flow rates of 0.02 kg/s and 0.03 kg/s under field conditions. Based on the air mass flow rate, the coated absorber reaches higher temperatures, approximately 5 oC to 9 oC, than the uncoated one. The acquired results illustrate that the coated SAH has nearly 4 oC to 5 oC higher maximum exhaust air temperature; hence, the coating strategy improves the thermal efficiency by 24.75% and 44% in two air mass flow rates of 0.02 kg/s and 0.03 kg/s, respectively.
T. C. Vadlamudi; R. Kommineni; B. P. Katuru; N. K. N. Injeti
Abstract
Gas turbines are always intended to give more specific work output for which continuous exposure to hot combustion gases is necessary. To increase the lifespan of the turbine blades active cooling should be applied to the High Pressure (HP) turbine blades. In the present work, a simple open cycle gas ...
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Gas turbines are always intended to give more specific work output for which continuous exposure to hot combustion gases is necessary. To increase the lifespan of the turbine blades active cooling should be applied to the High Pressure (HP) turbine blades. In the present work, a simple open cycle gas turbine is modeled to carry out thermodynamic analysis with different open loop steam cooling techniques: steam internal convection cooling (SICC), steam film cooling (SFC) and steam transpiration (STC) cooling. The effect of Turbine inlet temperature (TIT), Turbine blade temperature (T_b), and Compressor pressure ratio (CPR) on the coolant flow requirement and effect of T_b on the performance are estimated. The entire analysis is carried out with contemplation of variable specific heat (VSH) along with constant specific heats (CSH) for air and gas. Between VSH and CSH approaches, the former analysis leads to better performance from the first and second law efficiencies point of view. Irreversibility and Entropy generation rate are maximum in the combustor and they are less for VSH case in all cooling schemes and are decreased by 38.53%, 40.01%, and 40.40% for SICC, SFC and STC schemes respectively when compared with CSH(at TIT=1580 K, T_b=1123 K, CPR=19.1) analysis.
S. Jaikumar; S. K. Bhatti; V. Srinivas; S. B. Padal; D. Chandravathi
Abstract
This study is projected to regard as characteristics related to the viability of the preparation of methyl ester from Mesua ferrea oil through transesterification using Trisodium phosphate (Na3PO4) and Tripotassium phosphate (K3PO4). Na3PO4 and K3PO4 have high catalytic properties intended for the reaction ...
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This study is projected to regard as characteristics related to the viability of the preparation of methyl ester from Mesua ferrea oil through transesterification using Trisodium phosphate (Na3PO4) and Tripotassium phosphate (K3PO4). Na3PO4 and K3PO4 have high catalytic properties intended for the reaction of transesterification and cost-effective compared to other catalysts. The transesterification process was undergone at diverse operating constraints such as methanol to oil molar ratio (4:1 to 12:1), catalyst concentration (0.75 to 1.75%), and reaction temperature (55-70oC). The duration of transesterification was fixed at 60 min. The maximum yield was obtained at a molar ratio of 8:1 and a catalyst concentration of 1.25% at a reaction temperature of 65oC for the duration of one hour. The yield of Mesua ferrea oil methyl ester (MFOME) with K3PO4 catalyst has specified more compared to Na3PO4. Further, the MFOME was analyzed for physic-chemical properties and all the properties were found to be matched with ASTM standards. Particularly, the superior cetane number was achieved with MFOME. The biodiesel yield of RSM predicted values using both catalysts were well correlated with experimental results.
D. Basrur; J. Ishwara Bhat
Abstract
In this work, the preparation of activated carbons from agricultural product, the fenugreek seeds by two approaches, chemical and microwave activation methods were studied. The characterization of carbon materials were carried out using different techniques such as Fourier Transform ...
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In this work, the preparation of activated carbons from agricultural product, the fenugreek seeds by two approaches, chemical and microwave activation methods were studied. The characterization of carbon materials were carried out using different techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermo Gravimetric Analysis (TGA), X-Ray Diffraction (XRD). Adsorption experiment was carried out for the adsorption of two different basic dyes, Methylene Blue (MB) and Crystal Violet (CV) under varying conditions such as concentration, agitation time and temperature. The data acquired from concentration variation were found to fit well with Langmuir and also Freundlich isotherms. Kinetic studies revealed the fact that the system followed second order adsorption rate. Thermodynamic parameters such as ΔH≠, ΔS≠ and ΔG≠ were calculated from the obtained data on adsorption at different temperature.
Environment
U. N. Wilson; J. E. Sani; A. Yusuf; O. C. Eze
Abstract
This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature ...
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This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature for 28 days, while the other 16 beams and 48 cubes were cured for 28 days and kept for a period of 6 months to be observed for durability with respect to strength after testing. All the beams were tested under three-point loading system with a shear span, av = 2.5d. The results of the compressive strength showed that concrete made with 0.5% jute fibre for 28 days and 6 months gave percentage increase in compressive strength by 12%, 12.5%, 9.7% and 10.1% for grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. Percentage increase in shear strength were by 24.5%, 16.1%, 27.9% and 16.5% for concrete grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. The addition of the fibre to the concrete slightly reduced the workability of the concrete and increased the crack resistance of concrete.
H. B. Kulkarni
Abstract
A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild ...
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A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild steelcoated with black zinc having absorptivity of 0.94 were used for CPT. mass flow rate of working fluid was 4 l/h. Thermal performance of CPT collector was tested according to ASHRAE Standardmethods. Average instantaneous efficiency of closed cylindrical parabolic trough collector system was found to be 66%. The overall efficiency of CPT system is 71% which is best suited for solar thermal applications.
S. Saghafi; N. Mehrdadi; G. Nabi Bid Hendy
Abstract
Currently, the efficiency improvement of industrial wastewater treatment plant (IWWTP) has turned into a noticeable challenge for plants operator. In addition, decreasing the cost and energy consumption of wastewater treatment plants has attracted great interest by water agencies and IWWTP operators. ...
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Currently, the efficiency improvement of industrial wastewater treatment plant (IWWTP) has turned into a noticeable challenge for plants operator. In addition, decreasing the cost and energy consumption of wastewater treatment plants has attracted great interest by water agencies and IWWTP operators. Since IWWTPs are energy-intensive facilities, the need for cost-efficient and reliable treatment processes has significantly increased so as to meet the standards of environmental regulations and national goals. Determination of energy efficiency of IWWTPs is a starting point for any energy-saving initiative. In this paper, a case study has been carried out in 79 WWTPs in Iran's industrial zones to identify electrical energy efficiency indices (EEI). In order to achieve a reliable result, Data Envelopment Analysis (DEA) was applied by Lingo11 software. The electrical energy efficiency index was estimated by regression equations for plants with different level of treatment (ready to discharge to the river, irrigation of green spaces, and agriculture) using Minitab17 software. The obtained results enable IWWTP operators to identify the cost items to improve the productivity at plants.
S. Nasrollahpour; D. Yousefi Kebria; M. Ghavami
Abstract
Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application ...
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Phenol and its metabolites are among the hazardous organic compounds, due to their carcinogenicity, toxicity, long term persistence in the environment. The purposes of this study are the synthesis of organoclay as an adsorbent with high physicochemical stability, environmental compatibility and its application for remediation of aqueous solutions contaminated with phenol. In this research, organoclay was synthesized by the combination of sodium bentonite and Cetyl Trimethyl Ammonium Bromide (CTAB) surfactant with three different Cation Exchange Capacities (CECs). As well as, adsorption capacity of synthesized organoclay was determined during reuse until saturation. The results revealed that the removal efficiencies of phenol at concentrations of 100, 1000, 2000, and 3000 mg/L were 68, 84, 82, and 80%, respectively. In general, the use of organoclay can be an alternative to the complex and expensive systems for the removal of phenol from aqueous solutions with respect to its simplicity, high performance, and cost-effectiveness.
Energy
A. Jabbari; M. Basaki; M. R. Sheykholeslami
Abstract
In this paper, an axial flux permanent magnet generator for a 30 kW direct drive wind turbine is designed and the design parameters were optimized with the aim of achieving high efficiency. In order to reduce the cogging torque and electromagnetic torque ripple components, the air core topology has been ...
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In this paper, an axial flux permanent magnet generator for a 30 kW direct drive wind turbine is designed and the design parameters were optimized with the aim of achieving high efficiency. In order to reduce the cogging torque and electromagnetic torque ripple components, the air core topology has been used, and with the aim of increasing the power capacity of the generator, a modular structure has been used. The advantage of the modular design is that each module can be considered as a generator unit and depending on the wind speed conditions, the number of units corresponding to the wind speed can be placed in the circuit and the generator will always work with maximum efficiency. First, by using the governing equations, the dimensions and performance characteristics of the generator are determined, and then a generator prototype is fabricated based on the electromagnetic design. In order to evaluate the output performance of the generator, machine simulation was performed in Maxwell finite element analysis software and the characteristic curves of voltage, current and ohmic losses were extracted. In order to evaluate the accuracy of the results, the outcomes of the analytical method have been compared with the experimental tests results.
S. Abdoly Naser; F. Haghparast; M. Singery; H. Sattari Sarbangholi
Abstract
According to statistics provided by the Iranian Statistics Center,40% of energy consumption is related to the housing sector. Windows as a component of exterior wall, Responsible for 20-30% of all energy infiltration. Therefore, the purpose of this study, is to optimize residential windows in cold and ...
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According to statistics provided by the Iranian Statistics Center,40% of energy consumption is related to the housing sector. Windows as a component of exterior wall, Responsible for 20-30% of all energy infiltration. Therefore, the purpose of this study, is to optimize residential windows in cold and dry climate of Tabriz in order to reduce energy consumption. The research method is based on simulation with two methods "parametric optimization" and "genetic algorithm". The research tool is Design Builder software. So, the amount of annual gas consumption in the case study was received from the National Iranian Gas Company and then the basic research model is modeled in software and after converting the unit from kWh to m3 and validating the obtained results from simulation, in the next step, the type of glazing and frame are changed and then the sensitivity is analyzed by the two mentioned methods. The results showed that by replacing windows with triple glazed-glazing with low emission coating filled with argon, krypton and xenon gas and UPVC frame with clear double glazed-glazing filled with argon gas and iron frame, annual gas consumption for heating decreased by 52.43%, 55.34% and 56.60% and the heat loss from the windows is reduced by 7.97%, 9.54% and 10.49%, respectively.
T. Y. Yee; M. Omar Fatehah
Abstract
Silicon dioxide (SiO2) in nanoscale had been detected as waste product in river water for the past two decades and it is recently proven to have adverse effects toward human and animal health, the ecosystem and water treatment system. The removal of SiO2 nanoparticles (NPs) from water still remains a ...
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Silicon dioxide (SiO2) in nanoscale had been detected as waste product in river water for the past two decades and it is recently proven to have adverse effects toward human and animal health, the ecosystem and water treatment system. The removal of SiO2 nanoparticles (NPs) from water still remains a challenge due to its small size and unknown interactions within the water body. In this study, dynamic light scattering (DLS) technique was applied to characterize SiO2 in terms of surface charge and particle size as a function of pH within the range of 2 to 11 to analyze the aggregation behavior and significance of the intermolacular interactions in deionized (DI) water and tap water. DLS analysis identified both pH values of the point of zero charge (pHPZC) of SiO2 NPs in DI water and tap water at pH 3.2 and pH 2.8 respectively. The initial pH was discovered at 7.1 in tap water with a mean particle size of 346 nm and an average surface charge value of -27 mV compared to initial pH of DI water which was 5.4 with mean particle size of 295 nm and an average surface charge value of -33 mV. It was found that both in DI water and tap water, SiO2 NPs aggregated and increased in particle size but reduced in surface charge when pH slowly decreased towards their respective pHPZC from the initial pH by adding 0.25M of hydrochloric acid. The mean particle size at pHPZC in DI water is measured at 1750 nm larger compared to the mean particle size in tap water indicating that the presence of other ions in tap water suppressed the aggregation process. In conclusion, results suggests that pH does influence the surface charge of SiO2 NPs and affect the stability behavior and its interaction processes in aqueous suspensions.
A. Dutta; S. M. Ullah
Abstract
In this research work, the performance parameters , such as fill factor (FF), external quantum efficiency (EQE) , maximum power density and carrier concentration profile of a planar hetero-junction poly 3-hexyl thiophene (P3HT) / phenyl-C61-butyric acid methyl ester (PCBM) photovoltaic cell has ...
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In this research work, the performance parameters , such as fill factor (FF), external quantum efficiency (EQE) , maximum power density and carrier concentration profile of a planar hetero-junction poly 3-hexyl thiophene (P3HT) / phenyl-C61-butyric acid methyl ester (PCBM) photovoltaic cell has been simulated for different values of carrier mobility where the simulation has been performed under the consideration of incident solar radiation of 1 kW/m2 irradiance, air mass of 1.5, ambient temperature of 300K and indium tin oxide (ITO) and aluminium (Al) has been considered as the anode and cathode of the P3HT/PCBM solar cell respectively. The performance parameters has been determined for electron mobility of 5 × 10-4 , 5 × 10-3 , 5 × 10-2 and 5 × 10-1 (cm2/V.s) at the acceptor and hole mobility of 1 × 10-4 , 1 × 10-3 , 1 × 10-2 and 1 × 10-1 (cm2/V.s) at the donor layer. Carrier concentration profile has been studied for 0.4 and 0.5 V junction voltage and for different values of carrier mobility. Finally highest external quantum efficiency of 2.413% and maximum power density of 24.13 W/m2 has been obtained for hole mobility of 1 × 10-1 (cm2/V.s) and electron mobility of 5 × 10-1 (cm2/V.s).
N. Shahbahrami; A.R. Hajbari; A.J. Novinruzer
Volume 1, Issue 1 , January 2010
Mirtaghi Mirmohammadi; M. Hakimi; A. Ahmad; M. Mohammadyan; K. Kamel
Volume 1, Issue 2 , April 2010