Environment
I. U. Siloko; E. A. Siloko
Abstract
This paper focuses on the interdependence between rainfall and temperature and their joint effect. Rainfall and temperature are vital climatic variables for agricultural productivity and other human activities. Despite the importance of rainfall and temperature, there are difficulties associated with ...
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This paper focuses on the interdependence between rainfall and temperature and their joint effect. Rainfall and temperature are vital climatic variables for agricultural productivity and other human activities. Despite the importance of rainfall and temperature, there are difficulties associated with accurate analysis of their joint distribution due to the possibility of interrelationship between the variables. Several studies have been conducted by researchers on the interaction between climatic variables in order to ascertain their effects on the environment because temperatures are observed to be undergoing changes regularly. The analysis of rainfall and temperature for exploratory and visualization purposes is investigated because underlying structures and patterns do form the basis of decisions by government and regulatory agencies. This study employs the statistical approach in investigating the interdependence between rainfall and temperature in Ekpoma, Edo State, Nigeria for a period of five consecutive years from 2016 to 2020 using the Gaussian kernel estimator. The results of the investigations using some statistical indicators establish that there is irregular pattern of rainfall which is occasioned by changes in temperature. The variability of rainfall is mostly prominent in two years which are 2017 and 2019 with 29.43mm and 27.74mm as maximum amount of rainfall respectively. The results also demonstrate that the performance of years with high standard deviations are better than that of low standard deviations. Again, the performance of years with high negative correlation coefficients and high negative covariance of rainfall and temperature is better than years with weak correlations and low covariance.
Water Resources Engineering
B. Oghati Bakhshayesh; F. Salmasi; S. Haji Azizi
Abstract
Underground water levels and pore water pressure can be increased as a result of heavy rainfall which can lead failure of earthen slopes. Retaining walls are the most well-known structures in order to increase earthen slope stability. In this study, the stability of earthen slopes is numerically simulated ...
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Underground water levels and pore water pressure can be increased as a result of heavy rainfall which can lead failure of earthen slopes. Retaining walls are the most well-known structures in order to increase earthen slope stability. In this study, the stability of earthen slopes is numerically simulated in critical hydrological situations. The simulations included pore pressure behind the retaining walls which lead to instability. Among the investigated parameters were: precipitation intensity, soil type, position and the diameter of drainage passages. Both horizontal and chimney drainages were simulated for the study. For fine-grained soils with intensive precipitation, using a single horizontal drainage passageway could not maintain sufficient stability for the retaining wall. Precipitation could have severe impact on stability in which increase of 5 to 15 mm/h would increase pore pressure from 7.09 kN to 75.39 kN which is so dramatic change. For coarse-grained soils, a retaining wall provides stability with a single horizontal drainage pipe; the horizontal pipe is able to discharge all the excess water behind the retaining wall. A chimney drainage system provided the best results, and the stability of the retaining wall did not endanger, even under the worst circumstances. Linear and non-linear regression relations were produced in dimensionless form which are providing 0.97 for R2 and 0.11 for RMSE values which implys the accurcy of equations. The accuracy of the regression determine their usage in practical applications.
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.
Energy
H. Eskandari
Abstract
Increasing demand for agricultural products and production of resource constraints- especially the limitation of cultivable areas - have made the highest yield per unit area the main goal of agricultural producers. Agriculture is a system exhibiting high energy consumption and production. Since energy ...
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Increasing demand for agricultural products and production of resource constraints- especially the limitation of cultivable areas - have made the highest yield per unit area the main goal of agricultural producers. Agriculture is a system exhibiting high energy consumption and production. Since energy has a direct impact on the efficiency of crop production, a sustainable agricultural system needs to be analyzed in terms of its input and output energy to determine the total consumed energy of production per unit area. The difference between input and output energy determines energy efficiency of an agronomical system. Input energy requires being well analyzed to reduce energy consumption and increase energy efficiency. This paper reviews energy efficiency indices based on energy consumption during planting and harvesting. To enhance energy efficiency of agronomical systems, some strategies are discussed in detail, including using high quality seeds, minimum tillage systems, direct seeded rice, weeds control especially in irrigation canals and plant nutrition through agronomical management. Although some agronomical strategies -like complementary irrigation in dry land farming systems- increase input energy, they increase crop yield. However, when output energy, resulting from the rise in crop yield, is higher than input energy, the system energy efficiency improves. Still, some inputs cannot be altered according to regional conditions which are often related to harvest stages operations.
Energy
J. Ahmadi; S. M. Maddahi; R. Mirzaei
Abstract
All important decisions that affect the thermal performance of the building are made in the early stages of design. Accordingly, in this research, the initial stage of architectural design which is related to space plan was targeted. The aim of this research is the perfect approach to evaluate, and optimize ...
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All important decisions that affect the thermal performance of the building are made in the early stages of design. Accordingly, in this research, the initial stage of architectural design which is related to space plan was targeted. The aim of this research is the perfect approach to evaluate, and optimize the energy a set of alternative spatial layout solutions through the functional computational design model. The method of this research includes the production of coherent design solutions and the evaluation and optimization of the energy performance of the selected solutions. In the first part, space allocation at a level produces the plan through an evolutionary technique. In the next step, certain plans were evaluated for energy performance, performance rank, and optimization. The energy simulation tool is Honeybee and Ladybug plugins,. The optimization tool is Pareto Evolutionary Algorithm in the Octopus plugin. The reproduction rate, the mutation rate and the possibility of mutation were 0.9, 0.8 and 0.2, respectively. The results showed that each algorithm is a suitable tool for design solutions, thermal performance of floor plans, helping architects’ perspective in the decision-making process, and speeding up the design process. Finally, based on the optimization, the final result of the research algorithm is 70 elite answers in the Pareto front. Only during the Pareto front optimal responses, energy consumption can be reduced by more than 30%; in daylight time and more than 39% improvement was achieved.
Environment
A. Alizadeh; H. Nowzari
Abstract
In the wildlife management, maintaining water quality and quantity, especially in areas that are faced with relative constraints of water resouces, are considered as one of the planning pillars. Natural springs and artificial troughs in the KooheHava and TangeKhoor Free Area are the only sources of water ...
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In the wildlife management, maintaining water quality and quantity, especially in areas that are faced with relative constraints of water resouces, are considered as one of the planning pillars. Natural springs and artificial troughs in the KooheHava and TangeKhoor Free Area are the only sources of water suppliers for wildlife of the area. The aim of this study was to investigate the microbial indices of water resources used by wildlife in this areas and to compare them with the Iranian national standard limit. In this study, 12 water sources including ten springs and two troughs were selected and sampling was carried out in two seasons of summer and autumn of 2020 and three samples from each water resources and a total of 72 samples were collected throughout the study period and the parameters of total coliform, fecal coliform, temperature, turbidity and pH were measured. The data were analyzed by One sample t-test, Paired sample t-test, Independent sample t-test, analysis of variance and Spearman correlation matrix. The results showed that the means of total coliform were higher than the standard limit in all samples with the exception of no. 4 and 12 springs and the means of fecal coliform were higher than the standard limit in all samples with the exception of no. 2, 4, 8, 10, 11 and 12 water resources both during summer and autumn. In summer, with increasing evaporation, the amount of pollution load of water resources was higher than autumn. However in autumn, the number of polluted water resources was higher which was due to the transmission of microbial contaminations caused by human and animal feces via rain. The results of correlation showed a decrease or an increase in turbidity, temperature or pH did not affect the amount of coliforms because despite the strong correlation between total coliform and fecal coliform, no correlation was found between them and physicochemical factors of water. Therefore, considering the temporal and spatial variability of fecal coliforms and their effect on disease, death and reduction of wildlife populations, optimizing and disinfection of water resources with chlorine and dredging them are recommended.
Energy
F. Akhlaghinezhad; H. Bagheri Sabzevar
Abstract
Considering the global energy crisis and the need to reduce energy consumption while providing thermal comfort to occupants, building performance prediction using building simulation programs requires higher accuracy of output data. Therefore, it seems necessary to study the impact of occupant behavior, ...
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Considering the global energy crisis and the need to reduce energy consumption while providing thermal comfort to occupants, building performance prediction using building simulation programs requires higher accuracy of output data. Therefore, it seems necessary to study the impact of occupant behavior, which is the main source of uncertainty in residential buildings. The traditional courtyard houses, which are recognized as a successful passive house model, respond to different climatic conditions. Therefore, this research focuses on this building type to analyze occupant window opening control scenarios and determine which control works better. For this purpose, several probabilistic controls and their effects on the adaptive thermal comfort of occupants in zones around a central courtyard were compared in the three cities of Yazd, Bandar Abbas, and Tabriz. Energy Plus was used as a simulation program for the application of Grasshopper's energy management system (EMS) along with the Ladybug and Honeybee environmental plugins. The results show that the window control algorithms can increase the adaptive thermal comfort of occupants by 25.7%, 32.2%, and 20.3% in each of the climates of Yazd, Bandar Abbas, and Tabriz cities, respectively. Indoor and outdoor temperature were the most significant variables for opening windows in the warm and cold seasons, respectively.
Energy
A. Haghani; M. Jahangiri; R. Riahi; M. Golali Jonaghani; A. Baharizadeh
Abstract
The use of fossil fuels leads to greenhouse gas emissions, global warming, and secondary consequences such as desertification and winds in the Middle East and Africa, including Egypt. The use of renewable energy is the most appropriate solution to prevent the emission of polluting gases. Egypt is one ...
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The use of fossil fuels leads to greenhouse gas emissions, global warming, and secondary consequences such as desertification and winds in the Middle East and Africa, including Egypt. The use of renewable energy is the most appropriate solution to prevent the emission of polluting gases. Egypt is one of the best places to use solar water heating systems, located in the solar belt. In this paper, for the first time, the best place to use solar water heater (SWH) systems is examined using TSOL 2018 R(1) software and climate data for residential apartments in 35 stations in Egypt. The results showed that Sharm el sheikh station with supplies 96.8% of its total heat needs is the most suitable station for using solar water heating systems. According to the studies performed, using solar water heaters in the studied stations generated good energy savings annually (production of 134.5 GWh of solar heat). Also, greenhouse gas emissions were significantly reduced (preventing the emission of about 39.2 tons of CO2 pollutants per year) and as a result, the government should turn to the use of clean and renewable energy.
Energy
M. R. Hayati; S. Ranjbar; M. R. Abdar; M. Molaei Nasab; S. Homayounmajd; M. Esmaeili Shayan
Abstract
With countries throughout middle east and north Africa pursuing ambitious targets for a transition to renewable energies, the political economy of a region predominantly analyzed through the prism of fossil fuels is on the verge of radical change. As hydrocarbon prices decline, the low-cost producers ...
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With countries throughout middle east and north Africa pursuing ambitious targets for a transition to renewable energies, the political economy of a region predominantly analyzed through the prism of fossil fuels is on the verge of radical change. As hydrocarbon prices decline, the low-cost producers of Middle East have an advantage and should be the last to leave the market. The world will demand proportionally more of the region’s oil and gas. Nearly half of the world's oil is located in Middle East, which has long been referred to as the "energy axis" of the planet. In the meanwhile, as the nations of this area progress towards the future, they have realized the need of supplying energy from these other sources, such that the utilization of renewable energy sources, such as the sun, has attracted considerable interest. This study analyzed and assessed these attractions in addition to five middle eastern nations and Turkey, which is located in middle east, close proximity to this area. The approach of comparing government incentives in the development of renewable power plants was used in this study. The final findings revealed the current status of this energy in the target nations. This study may give the target countries and other nations in the middle east with a wealth of information for the formulation of effective policies for the use of renewable resources.
Energy
A. A. Sheikh Aleslami; H. Sadeghi
Abstract
Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical ...
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Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical simulation, the K-epsilon model has been used. The study evaluated the flow around the tower in several deformation states and compared it with a model where the tower is modeled rigidly in the wind tunnel. The maximum coefficient of negative pressure (suction) at the top of the tower structure equals to -1.95, which occurs at q =90o, and the maximum coefficient of the positive pressure equals +1. Since the buildings near the tower are located a short distance from the tower, the shed's structure, which is located near the tower, has also been investigated. With the aid of Tecplot software. The wind pressure coefficients obtained from the wind tunnel test were plotted. As part of the wind loading analysis in the single-span and two-span shed models, the model is rotated with a step of 5o relative to the direction of wind application, and wind pressure is recorded.
Energy
N. Deb; M. Z. Alam; T. Rahman; M. S. Jami; M. F. Bt. Mansor; H. B. A. Tajuddin
Abstract
The world's most economically developed countries are facing an energy crisis caused by geopolitical instability, rising energy costs, global stock disruptions, and a shift towards low-carbon energy sources that has yet to be fully realized. Electrification of the transportation industry offers the advantages ...
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The world's most economically developed countries are facing an energy crisis caused by geopolitical instability, rising energy costs, global stock disruptions, and a shift towards low-carbon energy sources that has yet to be fully realized. Electrification of the transportation industry offers the advantages of increased energy efficiency and reduced local pollutants. Electric Vehicles (EVs) are environmentally friendly because they reduce fossil fuels usage even zero consumption, need fewer maintenance requirements, and lower operating costs than the vehicles powered by gasoline or diesel. However, this study focuses on comparing various energy management strategies (EMS) for a backup energy supply system for EVs. The hybrid power system (HPS) considered in this study includes DC-DC and DC-AC synchronous converters, as well as supercapacitors, batteries, and fuel cells. The EMS analyzed includes state machine control, classical proportional-integral control, equivalent consumption minimization, frequency decoupling, rule-based fuzzy logic, and fuzzy logic control. The HPS's efficiency, hydrogen fuel, supercapacitor or battery state of charge levels, and overall performance are evaluated as primary efficiency criteria. Additionally, the HPS not only increases system energy but also reduces the number of pack batteries required. This study designs and constructs the combined power systems to enhance EV power schemes with rechargeable battery power supplies. The results show that a 6-kW fuel cell hybrid increases the power system capacity to 408 kWh. Moreover, a novel method based on wavelet transforms of the instantaneous power of each energy source is used to quantify the stressors on each energy source that impact its life cycle. To validate all analyses and performance, a simulation model and an experimental test bench are created. Finally, simulation results demonstrate a synchronous converter with a 6-kW output power and 96% efficiency, validating the optimization results.
