Environment
Alireza Yousefi Kebriya; Mehdi Nadi; Ebadat Ghanbari Parmehr
Articles in Press, Accepted Manuscript, Available Online from 28 December 2023
Abstract
Mazandaran province, due to its strategic geographical location and high influx of tourists during holidays, coupled with the presence of power plants and industrial complexes, is facing pollution challenges. This research, conducted in 2022, focuses on monitoring nitrogen dioxide and ozone pollutants ...
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Mazandaran province, due to its strategic geographical location and high influx of tourists during holidays, coupled with the presence of power plants and industrial complexes, is facing pollution challenges. This research, conducted in 2022, focuses on monitoring nitrogen dioxide and ozone pollutants in the province and investigating the role of tourists during certain multi-day holidays. Utilizing Sentinel 5 satellite imagery, including daily images from holidays and non-holidays, the study compensates for the lack of regular pollution data in Mazandaran's monitoring stations by validating the satellite data against Tehran stations. Linear regression equations determine the levels of nitrogen dioxide and ozone pollutants, leading to the creation of an Air Quality Index map for Mazandaran during holidays. The results highlight a strong correlation (0.3-0.7) between satellite and ground data, with ozone pollutants exhibiting a higher correlation. The skew error is consistently zero, and the mean square error varies between 1.9-6.2 PPb for nitrogen dioxide and 1.1-5.1 PPb for ozone. Pollution estimates for different points in Mazandaran during holidays and non-holidays indicate higher ozone pollution compared to nitrogen dioxide. Ozone pollution is particularly unhealthy and very unhealthy during holiday periods, especially along the coastal areas, while non-holiday days show cleaner and healthier air quality. The pollution index map illustrates higher ozone pollution in coastal cities during holidays compared to other regions, emphasizing the impact of tourists. This research demonstrates the effectiveness of Sentinel 5 satellite in monitoring air pollution and underscores the significant influence of tourists and transportation on Mazandaran province's air quality.
Environment
Elaheh faghihnasiri; Farhad Qaderi; S. Mustapha Rahmaninezhad
Articles in Press, Accepted Manuscript, Available Online from 30 January 2024
Abstract
Industrial processes are among human activities that cause the production of a large volume of wastewater containing organic pollutants such as phenol and its derivatives. Soil remediation is crucial for enhancing environmental quality for both humans and other living organisms. This study investigated ...
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Industrial processes are among human activities that cause the production of a large volume of wastewater containing organic pollutants such as phenol and its derivatives. Soil remediation is crucial for enhancing environmental quality for both humans and other living organisms. This study investigated the use of an electro-peroxone system to remove environmental pollutants from soil. In conjunction with ozonation, the study employed electrochemically generated hydrogen peroxide using a carbon electrode, addressing concerns about transportation and storage. Experiments were structured using response surface methodology (RSM) with three variables: ozone dosages ranging from 4 to 8 l/hr, initial pollutant concentrations from 20 to 50 mg/kg, and treatment durations between 7 and 14 days. The effectiveness of phenol removal from soil was assessed by applying a consistent voltage of 2 V/cm to the soil samples in all experiments. Results revealed a negative correlation between initial pollutant concentration and ozone consumption and a positive correlation between treatment duration and pollutant removal efficiency. Optimal removal efficiency occurred with a 14-day treatment duration, an 8 l/hr ozone dosage, and a 20 mg/kg initial pollutant concentration. The electro-peroxone system's application indicates its potential as a sustainable, eco-friendly, and cost-effective approach to soil remediation for pollution.
Energy
Hamed Kamelnia; Afsaneh Ghalehnovi
Articles in Press, Accepted Manuscript, Available Online from 05 February 2024
Abstract
Electrochromic Glazing (EC) has seen a significant surge in adoption today, primarily attributed to its pivotal role in enhancing visual comfort, mitigating excessive heat, regulating cooling and heating requirements, and curbing lighting consumption, especially within office buildings. Moreover, electrochromic ...
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Electrochromic Glazing (EC) has seen a significant surge in adoption today, primarily attributed to its pivotal role in enhancing visual comfort, mitigating excessive heat, regulating cooling and heating requirements, and curbing lighting consumption, especially within office buildings. Moreover, electrochromic glazing effectively contributes to glare control. This research aims to explore the impact of electrochromic glazing, as compared to conventional clear windows, on both the south and north facades, with the overarching goal of enhancing thermal and visual comfort within an office complex located in Mashhad. The research process unfolds in two key steps. Firstly, a comprehensive building simulation was conducted to assess daylight performance and gauge thermal and visual comfort using the GrassHopper plugin. Ubsequently, the Honeybee and Ladybug plugins were harnessed to evaluate the Discomfort Glare Probability (DGP) index and the Useful Daylight Illuminance (UDI) index. The findings of this study underscore the compelling advantages of electrochromic glazing over conventional clear windows as a prime choice to maintain balanced daylight levels throughout the day.
In practice, using electrochromic glazing on both north and south facades of a building reduces the annual heating and cooling energy demand by 6.5% and 4.5%, respectively. Additionally, it has a significant impact on reducing intrusive light radiation and intolerable glare levels compared to reference transparent windows, with reductions of 40% and 34.52%, respectively.
Energy
Abbas Dehghani Rayeni; Seyyed Abdolreza Gandjalikhan Nassab
Articles in Press, Accepted Manuscript, Available Online from 09 February 2024
Abstract
In the present paper, the effect of inclination angle on the free convection airflow inside the cavity of compound parabolic collectors and also on the performance of the thermal system is examined. In analysis, the airflow equations for computations of velocity, pressure, and temperature fields and ...
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In the present paper, the effect of inclination angle on the free convection airflow inside the cavity of compound parabolic collectors and also on the performance of the thermal system is examined. In analysis, the airflow equations for computations of velocity, pressure, and temperature fields and the conduction equation for obtaining the glass cover and absorber tube temperatures are solved by the finite element technique using the COMSOL multi-physics. For this purpose, the well-known κ-ε turbulent model is employed with the Reynolds average Navier Stokes scheme. Theoretical findings reveal that the pattern of air-free convection flow and also the temperature distribution are much affected by the collector inclination angle, such that the symmetric bi-cellular air flow at zero inclined angle changes to two non-symmetric recirculated zones at a large value of the till angle. This phenomenon causes a slight increase in thermal efficiency and leads to a more uniform air temperature distribution inside the collector. Numerical findings are validated by comparison with experimental data published in the literature.
Energy
Hadi Farzan; Mohammad Hossein Shahsavari
Articles in Press, Accepted Manuscript, Available Online from 10 February 2024
Abstract
This study analyzes the thermal efficiency of a new perforated cross-flow solar air heater (SAH) integrated with encapsulated phase change material (PCM) by using an experimnetal method. Since SAHs represent low thermal efficiencies, this study introduces a novel SAH that uses two methods to address ...
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This study analyzes the thermal efficiency of a new perforated cross-flow solar air heater (SAH) integrated with encapsulated phase change material (PCM) by using an experimnetal method. Since SAHs represent low thermal efficiencies, this study introduces a novel SAH that uses two methods to address this problem: the perforated absorber with cross-flow configuration and encapsulated latent heat storage (PCM) units. The perforated cross-flow configuration improves the turbulence and, consequently, the heat exchange rate in SAHs and improves instantaneous efficiency. PCM units store thermal energy, prolong the operating period, and increase long-term efficiency. To perform thermal analysis, a perforated SAH with encapsulated PCM units was fabricated and tested outdoors at mair = of 0.012 kg/s and 0.024 kg/s in autumn while ambient and operating parameters were monitored. The experimental data reveal that the outlet temperature reaches the peak value of 38 oC and 32 oC at mair = 0.012 kg/s and 0.024 kg/s, respectively, 12 oC and 6 oC higher than the ambient temperature. During the day, the charge/discharge process occurs in the encapsulated PCM units, avoids sharp temperature gradients and flattens the outlet and absorber temperatures’ profiles. The fabricated SAH reaches the highest thermal efficiency of nearly 83.7% at mair = 0.024 kg/s, which is a suitable value compared to common SAHs.
Energy
Farhaad Nasiri Khamesloo; Davood Domiri Ganji
Articles in Press, Accepted Manuscript, Available Online from 20 March 2024
Abstract
The dissipation of heat generated in electronic and industrial chips is essential for the health of these components. For this purpose, one of the best choices is a microchannel heatsink, which offers a lower pressure drop compared to other channels while maintaining a high heat transfer rate. In this ...
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The dissipation of heat generated in electronic and industrial chips is essential for the health of these components. For this purpose, one of the best choices is a microchannel heatsink, which offers a lower pressure drop compared to other channels while maintaining a high heat transfer rate. In this study, a fractal microchannel heatsink, introduced in recent years, has been numerically investigated. To enhance the performance of the microchannel, two types of fins have been added to the microchannel walls, resulting in the creation of two new geometries. In the first new geometry, fins are placed at the bottom of the microchannel, while in the second one, fins are placed on the sidewalls of the microchannel. It is worth mentioning that the volume of fins used is consistent across both geometries. Thermal and hydraulic parameters have been examined, revealing that both new geometries increase the Nusselt number, with the highest increase observed in the microchannel with fins on the sidewalls, amounting to 28%. Additionally, both geometries increase the pumping power, with the highest increase observed in the microchannel with fins at the bottom, reaching 120%. Finally, by evaluating the performance coefficient, it was determined that the microchannel with fins on the sidewalls increases the overall performance by 3 to 6% across different flow rates, whereas the microchannel with fins at the bottom reduces the system's performance by 7%. Therefore, for efficient dissipation of the generated heat, it is preferable to use a microchannel heatsink with fins on the sidewalls.
Energy
Maryam Rafinejad; Abbas Ghayebloo
Articles in Press, Accepted Manuscript, Available Online from 20 March 2024
Abstract
In recent decades, problems such as air pollution and the reduction of fossil fuel resources led to the development of electric vehicles. Wireless power transmission is an efficient and reliable way to charge fixed and mobile electric vehicles. One of the main problems in the dynamic wireless power transmission ...
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In recent decades, problems such as air pollution and the reduction of fossil fuel resources led to the development of electric vehicles. Wireless power transmission is an efficient and reliable way to charge fixed and mobile electric vehicles. One of the main problems in the dynamic wireless power transmission method is the amount of constant power transmission and its fluctuations. The purpose of this paper is to compare six different types of winding structures for choosing the best type of winding for the transmitter side in the application of dynamic charging of electric vehicles. In this paper, the winding function method is used for more accurate modeling of coils in terms of spatial harmonics and calculation of their self and mutual inductances by changing the location of the vehicle. Also, for coil excitation, instead of using the common single-phase inverter, a three-phase type is used to reduce the power ripple. The comparison is made in the aspect of the transmission power amount and its ripple. Modeling and simulation results are presented to confirm the results
Energy
Ehsan Mehrabi Gohari; iman pishkar; ehsan omidian
Articles in Press, Accepted Manuscript, Available Online from 25 March 2024
Abstract
In this Research, the Energy and Exergy analysis of the Steam Power-plant of the ninth refinery of South Pars Complex has been studie. Fristly, according to the thermodynamic characteristics, pressure, temperature , flow rate and the type of fluid in terms of saturated water, dense liquid and super heat ...
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In this Research, the Energy and Exergy analysis of the Steam Power-plant of the ninth refinery of South Pars Complex has been studie. Fristly, according to the thermodynamic characteristics, pressure, temperature , flow rate and the type of fluid in terms of saturated water, dense liquid and super heat steam, enthalpy and entropy quantities were calculated and then using the Energy and Exergy balance relationships, the losses and efficiency of various equipments have been calculated. The results of Energy analysis showed that Boiler with 62.09 MW, Drum 107 with 17.75 MW and Deaerator with 14.17 MW have the highest energy loss and the efficiency of the first law is 41%. Also, based on the results of Exergy analysis, Boiler with 94 MW, Heat exchanger with 5.297 MW and Drum 107 with 5.233 have the highest amount of Exergy destruction and the efficiency of second law is 33%. Also, the results showed that due to the use of the steam output from the turbine in other operating units in the studied refinery, the condensers have less Exergy destruction and Energy losses compared to other power-plants. In addition, by using the solution proposed in this research to heat the input air of the combustion chamber through hot water coming out of the Continues Blow Down(CBD), it is possible to significantly increase the Exergy of the input air.
Energy
Masoomeh Bahramisamani; Mehdi Jahangiri
Articles in Press, Accepted Manuscript, Available Online from 03 April 2024
Abstract
Using wind energy for hydrogen production in Iran can be important for reasons such as abundant wind resources in Iran, reducing dependence on fossil fuels, ensuring clean energy supply, the potential for hydrogen exports, technology development and job creation. Therefore, this study signifies the first ...
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Using wind energy for hydrogen production in Iran can be important for reasons such as abundant wind resources in Iran, reducing dependence on fossil fuels, ensuring clean energy supply, the potential for hydrogen exports, technology development and job creation. Therefore, this study signifies the first exploration into the potential for generating electricity and producing hydrogen in ten wind-rich cities in Iran. HOMER V.2.81 software was used for simulations, and the wind data used are averaged over a 25-year period. The results show that in Iran, the price range for wind power is $0.515-$0.620 per kWh in the top 10 stations. Bandar Abbas, Parsabad, and Khalkhal had the best economic and environmental performance, respectively. The highest percentage of renewable electricity production is 71% in Bandar Abbas. Finally, the amount of hydrogen produced based on four common electrolyzer types in Iran was investigated. The total annual hydrogen production per ton for SOE, MCE, AE, and PEME electrolysis method at the examined stations is 131.29, 93.43, 40.99, and 30.69, respectively. According to the results, the highest hydrogen production with a value of 16.87 tons per year is related to the Bandar Abbas station and the SOE electrolysis method. The lowest hydrogen production, with a value of 2.36 tons per year, is related to the Alvand station and the PEME electrolysis method.
Environment
hassan Farsi; Mehrdad Rohani; Sajad Mohamadzadeh
Articles in Press, Accepted Manuscript, Available Online from 08 April 2024
Abstract
Facial feature recognition (FFR) has witnessed a remarkable surge in recent years, driven by its extensive applications in identity recognition, security, and intelligent imaging. The UTKFace dataset plays a pivotal role in advancing FFR by providing a rich dataset of facial images with accurate age, ...
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Facial feature recognition (FFR) has witnessed a remarkable surge in recent years, driven by its extensive applications in identity recognition, security, and intelligent imaging. The UTKFace dataset plays a pivotal role in advancing FFR by providing a rich dataset of facial images with accurate age, gender, and race labels. This paper proposes a novel multi-task learning (MTL) model that leverages the powerful Efficient-Net architecture and incorporates attention-based learning with two key innovations. First, we introduce an age-specific loss function that minimizes the impact of errors in less critical cases while focusing the learning process on accurate age estimation within sensitive age ranges. This innovation is trained using the UTKFace dataset and is specifically optimized to improve accuracy in age estimation across different age groups. Second, we present an enhanced attention mechanism that guides the model to prioritize features that contribute to more robust FFR. This mechanism is trained on the diverse and challenging images of UTKFace and is capable of identifying subtle and discriminative features in faces for more accurate gender, race, and age recognition. Furthermore, our proposed method achieves a 30% reduction in model parameters compared to the baseline network while maintaining accuracy. Extensive comparisons with existing state-of-the-art methods demonstrate the efficiency and effectiveness of our proposed approach. Using the UTKFace dataset as the evaluation benchmark, our model achieves a 0.62% improvement in gender recognition accuracy, a 2.35% improvement in race recognition accuracy, and a noteworthy 3.23-year reduction in mean absolute error for age estimation.
Energy
Neda Daei parizi; Mansour Nikpour; Hossein Fallah
Articles in Press, Accepted Manuscript, Available Online from 17 April 2024
Abstract
For reading and writing in classrooms therefore a lot of energy is consumed in educational spaces. Limitation of fossil fuels and environmental pollution are two subjects that demonstrate the importance and significance of the present study. Previous studies show that window size and configuration have ...
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For reading and writing in classrooms therefore a lot of energy is consumed in educational spaces. Limitation of fossil fuels and environmental pollution are two subjects that demonstrate the importance and significance of the present study. Previous studies show that window size and configuration have a significant effect on daylight quality but numbers and the ways of expansion of windows in horizontal and vertical directions of the wall have not been investigated in classrooms in hot and arid regions of Kerman city. The objective of this paper is to evaluate the daylight indicators in different classrooms when different numbers of windows (from 1 window to 5 windows) are applied both horizontal and vertical expansion in each window area from (10%c WWR to 60% WWR). This research has been done through the simulation of different classrooms in Design Builder software under Kerman weather data. Validation of Design Builder has been evaluated through experimental measurement of two actual classrooms and comparing the simulation results and experimental data. The findings of this research demonstrated that using a greater number of windows in classrooms causes a decrease in the amount of daylight penetrating the classrooms.
