Environment
A. Sezavar; H. Farsi; S. Mohamadzadeh
Abstract
Person re-identification (re-id) is one of the most critical and challenging topics in image processing and artificial intelligence. In general, person re-identification means that a person seen in the field of view of one camera can be found and tracked by other non-overlapped cameras. Low-resolution ...
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Person re-identification (re-id) is one of the most critical and challenging topics in image processing and artificial intelligence. In general, person re-identification means that a person seen in the field of view of one camera can be found and tracked by other non-overlapped cameras. Low-resolution frames, high occlusion in crowded scene, and few samples for training supervised models make re-id challenging. This paper proposes a new model for person re-identification to overcome the noisy frames and extract robust features from each frame. To this end, a noise-aware system is implemented by training an auto-encoder on artificially damaged frames to overcome noise and occlusion. A model for person re-identification is implemented based on deep convolutional neural networks. Experimental results on two actual databases, CUHK01 and CUHK03, demonstrate that the proposed method performs better than state-of-the-art methods.
Environment
M. Heydari; T. Tabatabaie; F. Amiri; S. E. Hashemi
Abstract
Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. ...
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Large volumes of contaminated industrial wastewater have caused growing concern among researchers and environmentalists. Benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) cyclic hydrocarbons in industrial effluents are often completely stable to biodegradation and must be treated before disposal. In this context, using adsorption processes is a potential alternative for treating a wide range of organic pollutants, especially aromatic compounds in industrial wastewater. This study investigated the preparation of MCM-41 from silica; extracted from rice husk ash; MCM-41 was green synthesized to evaluate the effect of mesoporous used in BTEXS removal of an aqueous medium using the Taguchi method. The aqueous solution contains cyclic hydrocarbons was synthetically prepred based on real industrial effluent in concentrations of 50, 100, and 150 mg/l using MCM-41 catalysts, in doses of 0.1, 0.5, and 1g, at different pH values. In the present study, the optimum results obtained by Taguchi method analysis were pH =11, for duration of 60 minutes, the concentration of cyclic hydrocarbon solution BTEXS 100 mg/l, and nanoparticle dose of 0.5 g. The maximum BTEXS removal of 77.36% was achieved by the use of hydrogen peroxide.
X. Chen; H. Jiang; H. Cheng; H. Zheng
Abstract
The current issue of global warming is prominent, and there are many factors that affect global temperature changes. Therefore, how to correctly judge the relationship between each influencing factor and global temperature changes and accurately find out the main reasons of global temperature rise which ...
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The current issue of global warming is prominent, and there are many factors that affect global temperature changes. Therefore, how to correctly judge the relationship between each influencing factor and global temperature changes and accurately find out the main reasons of global temperature rise which are the problems that must be considered and solved to alleviate global warming at present. According to previous official data, this paper proposed a correlation analysis method based on principal components to comprehensively analyze the relationship between natural disaster factors, human factors, and global temperature changes, and find out the main reasons that affect global temperature rise. Compared with traditional research methods, the new method provided in this paper can still remain scientific and accurate calculation results while reducing computational dimensions. The experimental results showed that in the relationship between natural disasters and global temperature changes, the average correlation coefficient of the principal component represented by biological disasters and geological disasters was the highest at 0.6097 and a test value of p<0.05, indicating a significant positive correlation between them and global temperature. However, the correlation coefficient of the principal component represented by floods and storms was negative, indicating a negative correlation between them and global temperature. In exploring the main factors affecting global temperature rise, both the total global population and the total global CO2 emissions had a significant positive correlation with global temperature. Among them, the average correlation coefficient of the total global population was the highest at 0.9972, and its weight also was the highest at 26.42%. Therefore, this indicates that the total global population is the most important factor affecting global temperature rise. This study can provide reference for countries to make decisions in response to global warming.
Energy
Z. Aouissi; F. Chabane; M. S. Teguia
Abstract
The study shows an experimental investigation for a solar air collector with a single pass by adding rectangular baffles for different positions inside the channel. The aim of this study is to improve the thermal efficiency for this collector, and that through testing four cases of baffles positions ...
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The study shows an experimental investigation for a solar air collector with a single pass by adding rectangular baffles for different positions inside the channel. The aim of this study is to improve the thermal efficiency for this collector, and that through testing four cases of baffles positions (mode 1, 2, 3, 4). The study was done under different operating conditions by changing the mass flow rates and positions of baffles. The results show the effectiveness of the baffles in improving the efficiency of the collector, The study also proved that the baffles positions affect thermal efficiency, where the greatest efficiency was recorded in the fourth mode and then in the positioning of obstacles at the middle of the channel for the mode 2 and the mode 4 with a percentage of 76.61 and 90.9, at mass flow rate m=0.0522 kg/s, while the pressure drop was very high in the mode 4, and after that the mode 2. Through the conditions of the study and taking into account all the results; we can say that the best case was mode 2.
Environment
J. E. Sani; T. S. Ijimdiya; G. Moses; A. A. Lawal
Abstract
The soil investigated for suitability checks, as a subgrade material in this study, was a crude oil contaminated (COC) soil treated using an electrokinetic technique. The index properties and compaction characteristics of the electrokinetic remediated (EKR) soil are natural moisture content was 10.97%; ...
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The soil investigated for suitability checks, as a subgrade material in this study, was a crude oil contaminated (COC) soil treated using an electrokinetic technique. The index properties and compaction characteristics of the electrokinetic remediated (EKR) soil are natural moisture content was 10.97%; The Atterberg limit test showed liquid limit, plastic limit, plasticity index and linear shrinkage of 36.50%, 22.05%,14.45 %, and 4.30%, respectively. The percentage of 62.80% passes 0.075mm sieve with a maximum dry density (MDD) of 1.77 Mg/m3, and the moisture content decreased from 13.2% to 11.81%. The soil is classified as A-6 according to AASHTO classification system and belong to clay of low plasticity CL or OL group according to the Unified Soil Classification System. The unconfined compression strength, (UCS), durability, and California bearing ratio (CBR) of the electrokinetic remediated soil improved marginally from 46.63kN/m2 to 92.64kN/m2; from 18% to 23%; and from 2.55% to 4.05% respectively. However, these results obtained, do not meet the minimum requirement of the Nigerian General Specification. As a result, it is advised for further research, that an EKR soil be stabilized using cement stabilization to achieve the desired subgrade strength.
Renewable Energy
S. Aghajani Afghan; R. Shafaghat; A. Aghajani Afghan; S. M. Hosseinalipour
Abstract
In this paper, the performance of a hybrid humidification-dehumidification (HDH) desalination system is experimentally studied. The system operates as an Open-Air Closed-Water cycle and utilizes a solar air heater to heat the input air to the humidifier. An Ammonia absorption refrigeration cooling cycle ...
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In this paper, the performance of a hybrid humidification-dehumidification (HDH) desalination system is experimentally studied. The system operates as an Open-Air Closed-Water cycle and utilizes a solar air heater to heat the input air to the humidifier. An Ammonia absorption refrigeration cooling cycle is used to condense the humid air, producing fresh water. Parameters such as temperature and relative humidity were measured in different stages of the system by using humidity and temperature sensors, and the thermodynamic analysis was carried out using EES software. The effects of the mass flow rate and temperature of the inlet air flow on the rate of desalination, COP, GOR, and the efficiency of the humidifier and the dehumidifier were studied. The analysis proved that the highest rate of water production and GOR were 150 g/h and 1.2, respectively. It was also perceived that with an increase in the air mass flow rate, the rate of water production and COP increased, while GOR and the efficiency of the dehumidifier diminished. This is while the efficiency of the humidifier remains nearly constant. It was also concluded that an increase in the temperature of the input air, leads to a fall in the GOR, while the other parameters show an increasing trend. Following the economic analysis of the system, the CPL was found to be $0.16 /L.
Energy
A. W. Tahiru; S. U. Takal; E. D. Sunkari; S. Ampofo
Abstract
Although Ethiopia is one of the world's fastest-growing economies, access to sustainable energy and cutting-edge clean energy technology remains a major concern. The government is making significant efforts to generate renewable energy and provide more access to its citizens. Despite this, traditional ...
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Although Ethiopia is one of the world's fastest-growing economies, access to sustainable energy and cutting-edge clean energy technology remains a major concern. The government is making significant efforts to generate renewable energy and provide more access to its citizens. Despite this, traditional fuels (charcoal, fuel wood, dung cakes, and agricultural waste) account for around 87 percent of Ethiopia's energy use, and they pose a range of health and environmental risks. Solar, hydro, wind, and geothermal resources abound in the nation, but only 5% of the country's total hydroelectric capacity is being used; while, the rest is either underutilized or underdeveloped. An in-depth look at Ethiopia's renewable energy potential, as well as the opportunities and problems it faces, is presented in this review. With a combined installed capacity of over 7000 MW, hydropower and wind power are the most promising renewable energy sources in Ethiopia as of yet. It is hoped that this assessment will shed light on how Ethiopia can harness and maximize the use of its abundant renewable energy sources.
Energy
H. Farzan; A. A. Abouee-Mehrizi; M. Khazali
Abstract
The current study introduces and analyzes a novel square cross-flow perforated solar air heater (SAH). Since the convection mechanism in SAHs is weak, numerous methods have been suggested to address this problem and improve thermal efficiency. Perforations and cross-flow configuration generate high turbulency ...
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The current study introduces and analyzes a novel square cross-flow perforated solar air heater (SAH). Since the convection mechanism in SAHs is weak, numerous methods have been suggested to address this problem and improve thermal efficiency. Perforations and cross-flow configuration generate high turbulency and, consequently, high convection rate resulted. Hence these methods have been applied to enhance thermal efficiency. To achieve this goal, an experimental setup was fabricated and tested at outdoor conditions for two air mass flow rates (mair) of 0.015 kg/s and 0.03 kg/s while several sensors monitored the collector’s heat dynamics and ambient conditions. The obtained results illustrate that outlet temperature reaches the peak values of 38 oC and 34 oC, which is only 6 oC and 7 oC lower than the maximum absorber temperature. This crucial issue proves a high heat exchange rate in the fabricated SAH that causes the absorber temperature to approach the outlet temperature due to high turbulency. The strong convection mechanism in the fabricated SAH improves daily thermal efficiency, in which its value reaches nearly 78.6% for the mass flow rate of 0.03 kg/s. In conclusion, the square cross-flow perforated SAH is an economy, applicable, compact collector, ensuring high thermal efficiency.
Environment
A. Kaviani Rad
Abstract
A global health and economic crisis was caused by a pandemic Covid-19 in 2020, which reduced human activity worldwide. As human activities decreased, researchers had the chance to evaluate the impact of humankind on the ecosystem as well as explore the causes behind natural occurrences like forest fires, ...
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A global health and economic crisis was caused by a pandemic Covid-19 in 2020, which reduced human activity worldwide. As human activities decreased, researchers had the chance to evaluate the impact of humankind on the ecosystem as well as explore the causes behind natural occurrences like forest fires, which are mostly caused by humans. To assess the effect of quarantine on the forest fire situation in northern Iran. Twelve indicators were retrieved from Sentinel satellites, which represent four groups: land surface temperature, air pollutants, vegetation, and humidity. As indicated by preliminary results, the risk of fire decreased by about 34% in 2020 compared with 2018–2019; however, it subsequently increased again in 2021–2022. This leads to the conclusion that Covid-19 had a positive impact on forest health, but there was still an element of uncertainty as different ecological variables come into play. To evaluate this hypothesis in different regions, it is necessary to conduct additional studies, especially using ground-based data. In light of the adverse economic consequences of Covid-19, it is recommended that forest protection policies be implemented more effectively.
Renewable Energy
S. M. Seyed Hoseini; A. Mohammadzadeh; M. Seighli; F. Rezaei
Abstract
With the increase in world population and limited energy resources, countries have faced the high demand of energy and energy consumption problem. The crisis that threaten countries and human societies are the limited resources of non-renewable (fossil) energy and the increase in environmental pollution ...
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With the increase in world population and limited energy resources, countries have faced the high demand of energy and energy consumption problem. The crisis that threaten countries and human societies are the limited resources of non-renewable (fossil) energy and the increase in environmental pollution caused by excessive consumption of fossil fuels and global warming. These factors have motivated researchers and investors in the energy sector to control and supply energy from renewable sources. The uncertainty caused by these generations can have many effects on the costs imposed on the network and the operation of the electricity networks, such as an increase in power outages and unsupplied energy. Network development planning is one of the important issues in the power system to meet the growth of electricity demand in the coming years due to urban development, increasing social welfare, energy security, and job creation. The final objective of this model is to minimize energy losses, investment and operating costs, unsupplied energy, and environmental pollutants. The proposed methods have been implemented by MATLAB software on the Garver electricity network and the IEEE 33-bus distribution network and solved by PSO algorithms. The final model can be effectively used for planning the supply chain of the conventional electricity network with the penetration of renewable energy-based generations in various economic, environmental, and social dimensions.
Energy
A. Amini; N. M. Nouri; S. Niazi; A. Abedi
Abstract
Surface-piercing propellers (SPP) are known as one of the most efficient propellers in marine sciences and maritime industries. In this study, different types of simulations were performed on an SPP in various rotational speeds in open water conditions, and a numerical study was also carried out on a ...
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Surface-piercing propellers (SPP) are known as one of the most efficient propellers in marine sciences and maritime industries. In this study, different types of simulations were performed on an SPP in various rotational speeds in open water conditions, and a numerical study was also carried out on a particular type of such propellers. In fact the main purpose of this paper is comparing the simulation results with the experimental results from past in order to derive a trustable soultion for future works. For this purpose, the surface-piercing propeller was simulated by OpenFoam software (an open source software with high range of capabilities) in order to analyze the results. The performance curve was then plotted and compared with the ones from open water tests. In this case the turbulance model of K-Epsilon RNG was used which is capable of increasing Y+ to 300 which is monitored at the end of the simulation with the maximum amount of 315 and the average of 80. Results showed that the curves followed the same pattern and trends in the numerical study, and the report pointed to similar findings. In conclusion, it was proved that the sliding mesh method was a proper way for simulating propellers, particularly SPPs. The curves for thrust and torque coefficients of the SPP were also compared with the literature and the efficiency curve was plotted.