فهرست مطالب

  • Volume:11 Issue: 1, 2020
  • تاریخ انتشار: 1398/12/27
  • تعداد عناوین: 14
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  • M. M. Benali *, Y. Hamad Pages 1-7
    In order to investigate the carbon flow transformation in the process of ethanol pre-fermentation anaerobic digestion (AD) of kitchen waste (KW), a isotope tracer analysis method was developed in this paper, that is, 13C6-glucose was added to the substrate (KW), and then gas/liquid chromatography-mass spectrometry were used to determine the intermediate products converted by labelled carbon source in 13C6-glucose. The results showed that the liquid sample was within the range of adding level 10~160 μg/L, the recovery rate was 88.8%~109% and the relative standard deviation was 2.01%~8.35%; while the gaseous sample was within the range of adding level 6.53~32.65 μg/L, the recovery rate was 83.5%~103% and the relative standard deviation was 3.19%~9.27%. Under established test conditions, after AD for 72 hours, the recovery rate of labelled carbon exceeded 90%, which indicated that the test method had good stability. This method can be used to interpret the metabolic pathway of kitchen waste in anaerobic digestion from the micro perspective, which provides technical support for the application of isotope tracer method in anaerobic digestion field.
    Keywords: anaerobic digestion, Carbon Isotope, Gas Chromatography-Mass Spectrometry, Liquid Chromatography-Mass Spectrometry
  • R. R. Honkalas, H. B. Kulkarni *, P. R. Kubade Pages 8-12
    Rapid development of the global economy demands huge amount of Energy. Transportation sector contributes major part of economy development. Fossil fuels like Petrol and Diesel are used for transportation and heavy duty vehicles. Higher rate of consumption of these naturally available fuels leads to its depletion and deterioration of environment. To solve such issue many researchers are interested in identifying and using alternative fuels for internal combustion engines. Biodiesel is renewable fuel and can be used as alternative fuel for Diesel engines. In present work Canola oil based Biodiesel (COB) is blended in Diesel with different concentration like B20, B40 and B60. Engine input variables like compression ratio (13:1, 15:1, 17:1) and load (4, 8,12kg) are considered to optimize the results. The Performance of Variable Compression Ratio (VCR) Diesel Engine is evaluated using Taguchi method. Analysis of variance is conducted to recognise the significance of input variables on Brake Thermal Efficiency, Brake power Specific Fuel Consumption. Results of optimization showed that load is the most crucial factor which affects the engine performance i.e. Increase in load decrease the Brake Thermal Efficiency, Brake Power and increases the Specific Fuel Consumption.
    Keywords: ANOVA, Brake Power, Brake Thermal Efficiency, Canola Based Biodiesel, Taguchi method, Variable compression ratio engine
  • W. M. Desta *, A. Befkadu Pages 13-18
    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.
    Keywords: Performance Evaluation, water distribution networks, Waternetgen Tools, Water Tap Flow Analysis
  • F. Mohammad Alinezhad * Pages 19-25
    Sunken garden is one of the elements of traditional Iranian architecture, formed with the attitude of conservation of environment and organizing a meaningful relationship with its surroundings. Many studies have been conducted to identify this element of traditional architecture and its functions, endorsing its valuable and considerable properties in respect for nature, harmony with the aims of sustainable development and energy conservation. One of the most important functions of this elements is providing cooling needs for residents in the hot summer months of desert areas of Iran without the need of fossil fuels consuming. The current article, as a descriptive-analytic study, aimed at a more comprehensive knowledge of passive cooling in sunken garden. To reach this goal, passive cooling and its types and sunken garden were first introduced. Then, their relationship with natural elements and the role of each element in achieving passive cooling in sunken garden were evaluated. The results revealed that sunken garden has been linked with natural elements in a way which cools this underground space of traditional buildings of hot and dry climate of Iran through heat prevention, heat modulation and heat dissipation.
    Keywords: Conservation of Energy, natural, Passive cooling, Sunken Garden
  • G. O. Olutona *, O. O. Daniel Pages 26-32
    Several nations of the world are facing crisis level of acute food security and malnutrition which required urgent attention. Melon very rich in protein, oil, minerals, vitamins and good source of energy. As a result, the high contamination of melon with heavy metals and pesticide residues threatens human and ecosystem. Organochlorine Pesticides (OCPs) and trace metals were undertaken in melon obtained from five major towns in Nigeria. Analytical instruments were used to analyze the extracted OCPs from dichloromethane and digested melon samples, respectively. The overall metal content per site of the studied elements in the selected sites was determined and it was in the following decreasing order: Mokwa > Bida > Suleja > Borgu > Saki. The mean metal concentrations were in the following decreasing order: Pb > Zn > Ni > Co > Cd. With exceptions of locations where Ni and Pb were below detection limit, the concentrations of Pb, Cd and Ni in other locations were above WHO/FAO recommended limit. Concentrations of Zn and Co were below WHO/FAO limits. Out of 17 isomers of OCPs analyzed only five isomers were detected. The overall OCPs content per site of the studied elements in the selected sites was determined and it was in the decreasing order: Bida > Borgu > Saki > Suleja. OCP was not detected in melon samples obtained from Mokwa. With exception of endosulfan II, endrin aldehyde, heptachlor, DDE and λ –BHC were above their respective maximum residual limit. Environmental monitoring and education are highly recommended.
    Keywords: Anthropogenic, Contamination, Food Security, toxicology
  • M. Imani * Pages 33-39
    Electricity demand forecasting is an important task in power grids. Most of researches on electrical load forecasting have been done in the time domain. But, the electrical time series has a non-stationary inherence that makes hard load prediction. Moreover, valuable information is hidden in the electrical load sequence which is not open in the time domain. To deal with these difficulties, a new electricity demand forecasting framework is proposed in this work. In the proposed framework, at first, a new feature space of electrical load sequence is composed. The provided domain involves complementary information about shape and variations of electrical load sequence. Then, the obtained load features are integrated with the original load values in time domain to allow a rich input for predictor. Finally, a powerful deep learning technique from the family of recurrent neural networks, named long-short term memory, is used to learn electricity demand from the provided features in single and hybrid domains. The following domains are investigated in this work: frequency, cepstrum, spectral centroid, spectral roll-off, spectral flux, energy, time difference, frequency difference, Gabor and collaborative representation. The experiments show that the use of time difference domain decreases the mean absolute percent error from 0.0332 to 0.0056.
    Keywords: Frequency Domain, Load forecasting, Long-short Term Memory, Time Domain
  • A. Zinabie *, B. Kebede Pages 40-50
    With urbanization impervious surfaces increase, drainage pattern changes, overland flow becomes speedy, flooding and environmental problems such as land degradation increases. The objective of this study is to evaluate the hydraulic performance of storm water drainage system of the study area. The drainage channels are filled with or blocked by silt and garbage, the blockage of drainage structures is due to flat areas and siltation of drainage system which leads to failures on roadways.  Spatial analyses were conducted using Arc GIS, Bentley Flow master, Google Earth pro and Auto CAD software’s as analytical tools. The hydrological analysis was computed by rational method. The existing depth and width of the storm water drainage channel were measured for all sub catchments of the town and used to determine the existing drainage capacity using Bentley Flow master. The existing condition drainage channel depths of sub-catchments 6,7 and 8 increased by 68.40%, 160.20% and 121.07%; and the widths by 55.44%, 116.83% and 100.98%, and the design discharge was also 9.29m3/s, 16.47m3/s and 9.13m3/s, respectively. Therefore, this study recommends improvement in the integration of road and drainage structure; integration of solid waste management system in order to prevent the over flowing of storm water as a result of blockage of drains; the stations of the road requires proper maintenance and suitable measures should be taken in order to make the road and storm water drainage structures serve for the intended purposes sustainably to the stakeholders.
    Keywords: Bentley Flow Master, Hydrologic Analysis, Storm Water, urbanization
  • S. A. Azeez *, U. Garba, B. G. Danshehu Pages 51-56
    Hydrogen production from glycerol via autothermal reforming (ATR) has been widely investigated. However, little is known about the influence of impurities in glycerol on thermodynamic performance of the process. This study focused on the effects of impurities in glycerol on hydrogen productivity, energetic and exergetic efficiencies. The model of the entire process was simulated under thermoneutral condition in Aspen HYSYS using pure glycerol (PG) and crude glycerol (CG) as feeds. The two cases were optimized for maximum hydrogen production. From the optimized results, the hydrogen production per mole of the feed was 4.937 and 6.160 for the case of PG and CG, respectively. The thermal and exergetic efficiency of PG as feed were computed as 79.51% and 57.04% while that of CG were obtained to be 77.7 and 54.08%, respectively. The exergy destroyed to produce 1 mole of H2 was found to be 133.5kJ and 157.3kJ for the case of PG and CG, respectively. It could be concluded that the presence of other constituents in CG contributed to increase in hydrogen productivity by increasing the energy demand of the plant but due to increase in both energy and exergy input, they decrease both the thermal and exergetic efficiencies.
    Keywords: Efficiency, Energy, Exergy, optimization
  • S. Prasad Lohani * Pages 57-60
    The composition of waste generated in urban areas of Nepal is primarily decomposable which provides scope to convert the waste into energy.  In addition, organic fraction of municipal waste is a serious environmental and economic burden in Nepal. In this study, samples from food waste were taken from household of Biratnagar Metropolitan city and Kathmandu University Canteen, Dhulikhel. The samples were analyzed for physical and chemical properties and biogas production. The feed containing 6% TS were analyzed for the potential of biogas production from the canteen food waste (CFW) of Kathmandu University (KU) and household food waste (HFW) from Biratnagar in ambient and control temperature (35 ℃) in a batch reactor.  This was also conducted for food waste mixed with 30% cow manure in both the conditions. The average total solid and volatile solid for BFW were 17.7 and 93.2% of TS and CFW were 19.9 and 90.2% of TS, respectively. In every run of the experiment, the volume changes of gas were monitored. Both in the ambient and the controlled temperature, biogas production and yield were higher when 30% cow dung as inoculum was added in both samples. Moreover, the biogas production and yield of CFW was also higher than the BFW at different conditions. This shows that food wastes characteristics and biogas production potential varies depending on the source of the food waste, inoculum added and operating condition for the anaerobic digestion process.
    Keywords: Biogas, Food waste, Inocolum, total solid, Volatile Solid
  • E. O. Ajala *, F. Aberuagba, M. A. Ajala, A. M. Ayanshola, T. D. Akpenpuun Pages 61-69
    Shea biodiesel (SBD) was produced and blended with diesel at various proportions to produce 100B (SBD), 75B, 50B, 25B, and D (diesel) as fuel types. The SBD and other fuel types were characterised by ASTM standard methods for its physicochemical properties. The fuel types were used in a compression ignition engine (CIE) to test for its fuel consumption, (FC) specific fuel consumption (SFC), brake thermal efficiency (BTE), exhaust temperature (ET) and emission characteristics hydrocarbon (HC), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide (NOx) and sulphur dioxide (SO2). The physicochemical properties of SBD in terms of density, kinematic viscosity, flash point, cloud and pour points, and cetane number were 884.7 kg/m3, 5.69 mm2/s, 165 oC, 12 oC, 9 oC and 55, respectively; while those of diesel were 860.4 kg/m3, 2.6 mm2/s, 73 oC, 2.4 oC, -9 oC and 49, respectively. The results were within the range of the standard. The results obtained at 12 Nm torque for SFC, FC, BTE, and ET for SBD were 0.21 kg/kW.h, 0.71 kg/h, 12.69%, and 365 oC, respectively, while those of diesel were 0.31 kg/kW.h, 1.12 kg/h, 8.46%, and 330 oC, respectively. These results show that the SBD and diesel possessed similarity in terms of performance. The SBD is environmentally friendly compared to diesel. This study shows that the SBD possessed quality alternative replacement to diesel suitable for a CIE.
    Keywords: Biodiesel, Compression ignition engine, Diesel, Emission, performance
  • S. Om Prakash *, T. Mathavaraj Ravikumar, M. Arulraj Pages 70-74
    Natural fibers such as banana, sisal, snake grass, coir, hemp, jute and so on are armed with enormous advantages like less weight, reliability, recyclability and environmental friendly nature. Such fibers may enhance the system’s performance by acting as additives with the thermoplastics in different perspectives. Besides the natural composites, hybrid composites facilitate the design of material with specific property matched to an application. In the present work an attempt has been made to manufacture and test the banana and snake grass short fiber reinforced hybrid polyester composites in random orientation and random lay-up. Methyl Ethyl Ketone Peroxide was used as the coupling agent and Cobalt Naphthalene as the catalyst. Hand layup technique was used to manufacture the composites. Relative volume fraction of the fibers was varied between 2.5-12.5% in the ratio 1:1. Properties like tensile strength and modulus, flexural strength and modulus  are measured  for the composites  by conducting  the appropriate tests according to  ASTM standards.
    Keywords: Hybrid composite, Mechanical properties, modulus, Natural Fiber, polyester, Strength
  • M. M. Mirzaei Darian *, A. M. Ghorreshi, M. J. Hajatzadeh Pages 75-78

    Solar energy is a feasible and efficient way to reduce environmental pollution which, in turn, can decrease the production of greenhouse gases. Iran with over 300 sunny days has a high potential for producing energy, including electricity through photovoltaic (PV) systems. Regarding this fact that Iran has the enormous resources of fossil fuels such as oil and gas, the government tends to expand its energy production by renewable systems, including photovoltaics. This paper is to evaluate the efficiency of photovoltaic system in one of the major provinces of Iran. In this study, a 4.8 kW photovoltaic power station in East Azerbaijan province was investigated. First, a simulation-analysis is carried out. Then the verification of the study is done using extracted experimental data. According to the results, the photovoltaic power plant generates 8334 kWh annually. Finally, the station is economically investigated. This economic analysis is carried out in accordance with the existing tariffs and policies in Iran.

    Keywords: Economic Parameter, performance, Photovoltaic system, Renewable Energy
  • A. W. Galata *, T. Demissei, M. K. Leta Pages 79-85
    The various water resources project planning and implementation need the knowledge of factors influencing watershed hydrology. Therefore, this study analyzed Hangar watershed hydrological responses to land use/land cover change (LULCC) from 1987 to 2017. In addition to the LULC data, the input data used for the soil and water assessment tool (SWAT) model simulation were the DEM data, soil data, and climatic data. The model calibrated and validated using measured streamflow data of 13 years (1990-2002) and nine years (2003-2011), respectively. The result after simulation indicated that the annual total water yield of the watershed decreased. The annual simulated stream flow through the study period is increased for wet and short rainy season whereas, decreased for dry season. An increase of wet season flow may result in flooding, and the reduction of dry season flow may affect water scheme practice. Therefore, this study enables the concerned body to curve the changes in LULC towards increasing vegetation cover so that, surface runoff that contributes to wet season flow will be reduced and infiltration that supply groundwater from which dry season/base flow contributed will be increased.
    Keywords: Land cover change, land use, Soil, Water Assessment Tool Model, Watershed Hydrology
  • N. Mamine *, F. Khaldi, N. Grara Pages 86-95
    The reuse of wastewaters of urban communes of Khmissa (Site 1), Hannancha (Site 2) and Souk Ahras (Site 3) rejected in the Medjerda wadi of Souk Ahras region (North-East Algeria) for agricultural purposes in the far North-East of Algeria is accompanied by health and environmental risks, the evaluation of which requires physico-chemical and parasitological characterization. Biweekly samples were taken from March to August 2019 at the three studied sites wastewaters discharges. The results revealed that the waters studied are characterized by high salt contents, negative redox potential and high levels of turbidity (97.28 ± 18.12 to 111.57 ± 13.11 NTU), suspended matter (TSS) (351.6 ± 15.52 to 397.33 ± 20.6 mg.L־1), ammonium (8.51 ± 1.94 to 11.19 ± 3.18 mg.L־1) and orthophosphates (3.69 ± 1.40 to 5.29 ± 1.78 mg.L־1), high values in BOD5 (120.62 ± 43.17 to 170.25 ± 32.34 mg.L־1of O2), and COD (286.73 ± 39.65 to358.9 ± 32.81 mg.L־1of O2) as well as the presence of some metallic trace elements such as cobalt (Co) and cadmium (Cd). Parasitological analysis shows high contamination of these irrigation waters by helminthes eggs, which exceed widely the standards of use of waste water in agriculture. The application of Principal Component Analysis (PCA) allowed to conclude that the waters of Medjerda wadi receive urban wastewater from surrounding areas and should not be reused directly in agriculture before being subjected to a processing, in order to improve their quality by meeting the required standards.
    Keywords: Agricultural, Environmental, Health, Medjerda Wadi, Principal component analysis, risks