Vol 7, No 1 (2024)

Table of Contents

Open Access
Original Research Article
Article ID: 6036
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by K. G. Chandan, B. Patil Mallikarjun
Therm. Sci. Eng. 2024 , 7(1);    120 Views
Abstract An investigation is conducted into how radiation affects the non-Newtonian second-grade fluid in double-diffusive convection over a stretching sheet. When fluid is flowing through a porous material, the Lorentz force and viscous dissipation are also taken into account. The flow equations are coupled partial differential equations that can be solved by MATLAB’s built-in bvp4c algorithm after being transformed into ODEs using appropriate similarity transformations. Utilizing graphs and tables, the impact of a flow parameter on a fluid is displayed. On velocity, temperature, and concentration profiles, the effects of the magnetic field, Eckert number, and Schmidt number have been visually represented. Calculate their inaccuracy by comparing the Nusselt number and Sherwood number values to those from earlier investigations.
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Open Access
Original Research Article
Article ID: 6137
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by Taiwo O. Oni, Bernard A. Adaramola, David Bamidele, Jerry Adaji, Isaac O. Akene, Oluwadunsin Osubu, Abraham Isiaka
Therm. Sci. Eng. 2024 , 7(1);    88 Views
Abstract The scarcity of the insulators that are required for refrigeration has made it necessary to use locally available materials that can achieve the desired refrigeration. This work presents the performance evaluation of a refrigerator utilizing a locally available material, which is wood particles that have been converted to particle board, as one of its insulators. A vapor compression refrigeration system was designed and fabricated to chill and preserve agricultural products, which are eggs, yogurt, and tomatoes. The various temperatures at which the agricultural products became chilled were compared with their theoretical preservation temperatures obtainable in literature, thereby evaluating the performance of the refrigerator. The temperature of 11 ℃, which was recorded for the egg in the present experiment, is lower than the theoretical preservation temperatures of 18 ℃ to 21 ℃ for an egg. The temperature of 7 ℃, which was recorded for the yogurt, is approximately equal to its theoretical preservation temperature of 5 ℃. The temperature of 8 ℃, which was recorded for the tomato, is lower than the theoretical preservation temperatures of 7 ℃ to 10 ℃ of tomato. This work has revealed that wood particles have the potential to achieve refrigeration, as well as chill and preserve agricultural products.
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Open Access
Original Research Article
Article ID: 6126
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by Erkan Dikmen, Arzu Şencan Şahin
Therm. Sci. Eng. 2024 , 7(1);    53 Views
Abstract The Organic Rankine Cycle (ORC) is an electricity generation system that uses organic fluid instead of water in the low temperature range. The Organic Rankine cycle using zeotropic working fluids has wide application potential. In this study, data mining (DM) model is used for performance analysis of organic Rankine cycle (ORC) using zeotropik working fluids R417A and R422D. Various DM models, including Linear Regression (LR), Multi-Layer Perceptron (MLP), M5 Rules, M5 Model Tree, Random Committee (RC), and Decision Tree (DT) models are used. The MLP model emerged as the most effective approach for predicting the thermal efficiency of both R417A and R422D. The MLP’s predicted results closely matched the actual results obtained from the thermodynamic model using Genetron software. The Root Mean Square Error (RMSE) for the thermal efficiency was exceptionally low, at 0.0002 for R417A and 0.0003 for R422D. Additionally, the R -squared ( R 2 ) values for thermal efficiency were very high, reaching 0.9999 for R417A and R422D. The findings demonstrate the effectiveness of the DM model for complex tasks like estimating ORC thermal efficiency. This approach empowers engineers with the ability to predict thermal efficiency in organic Rankine systems with high accuracy, speed, and ease.
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Open Access
Original Research Article
Article ID: 6027
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by Franz G. Rosner, Werner Pölz
Therm. Sci. Eng. 2024 , 7(1);    21 Views
Abstract A decarbonized society can only become reality if all potential greenhouse gas is leveraged. In order to achieve this, it is necessary to scrutinize all processes, to assess whether a high level of energy and material efficiency has been achieved and whether renewable energy sources are used to the maximum extent. In this investigation, we were investigating the corporate carbon footprint of a winery in Austria. All data, energy and material inputs were taken within the framework of a scenario analysis for one hectare of vineyard with a yield of a 5-year average of 5380 L. The energy and material input in a winery in Austria under the system limit considered in these calculations results in a GHG emission of about 1.04 kg per L of bottled wine (or 0.78 kg per 0.75-L bottle). On the other hand one kg of grapes would therefore cause 0.24 kg of CO 2 e. The GHG emissions for the production of a wine bottle in Austria causes 0.328 kg CO 2 equivalent emissions. The GHG emissions for washing (0.011 kg CO 2 equivalent emissions per bottle), on the other hand, amount to only 3.4% measured against a new bottle in Austria. The bag-in-box system can only be used once. This system leads to 59% higher GHG emissions per L compared to reusable bottles on the basis of 12 filling cycles (system sustainability – lightweight bottles). At a refill rate of 50% in a winery, GHG emissions are reduced to 4367 kg per ha (−32% compared to normal and new glass in the winery). The calculations show that refilling the wine bottle has the highest savings potential. Measures to achieve this multiple use should be implemented as soon as possible in the wine industry .
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Open Access
Original Research Article
Article ID: 6054
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by Madhab Chandra Jena, Sarat Kumar Mishra, Himanshu Sekhar Moharana
Therm. Sci. Eng. 2024 , 7(1);    27 Views
Abstract The gravure printing process is widely utilized for large-scale, high-quality, multi-colored printing tasks executed at high press speeds. This includes a diverse range of products such as art books, greeting cards, currency, stamps, wallpaper, magazines, and more. This thesis addresses the fire risks associated with gravure printing, acknowledging the use of highly flammable materials and the potential for static charge-related incidents. Despite its prevalence, there is limited research on fire prevention and control in gravure printing. The study employs field observations, stakeholder interviews, and an extensive review of literature on fire risk and control in printing press operations in India. It analyzes the causes of fires using the fire triangle model, emphasizing the role of heat, combustible materials, and oxygen in fire incidents within the printing press environment. The thesis categorizes preventive measures into fire prevention and fire suppression actions, focusing on reducing fire load, static charge mitigation, and implementing firefighting systems. It observes that poor housekeeping, lack of awareness, and inadequate emergency control plans contribute significantly to fire hazards in press facilities. Additionally, the research identifies key factors such as high press temperatures, low humidity, improper storage, and inadequacies in firefighting systems as potential causes of fires. It emphasizes the need for optimal environmental conditions, proper storage practices, and effective firefighting infrastructure within press facilities. The study concludes with comprehensive guidelines for loss prevention and control, including management programs, housekeeping, operator training, pre-emergency planning, preventive maintenance, and plant security. It also addresses safety measures specific to gravure printing presses, such as automatic sprinkler systems, fire hydrant system, carbon dioxide flooding systems, and portable fire extinguishers. In summary, this thesis provides valuable insights into the multifaceted nature of fire risks in gravure printing presses and recommends a holistic approach for effective fire prevention and control.
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Open Access
Original Research Article
Article ID: 5949
by Nan Lu, Chengxia Miao, Xiaozheng Lan
Therm. Sci. Eng. 2024 , 7(1);    22 Views
Abstract The mechanism is investigated for Wolff rearrangement/Staudinger [2+2] cycloaddition cascade and Pd-catalyzed, decarboxylative, formal [3+2] cycloaddition. Wolff rearrangement of 3-diazotetramic acid is determined to be rate-limiting step generates cyclic acyl ketene. The interaction of ketene with imine firstly results in zwitterion followed by conrotatory cyclization giving major cis-β-lactam. For synthesis of s-VECs, the epoxidation−cyclization cascade and hydrolysis give precursor of better performing exocyclic derivative. The reaction with 3-cyanochromone includes decarboxylation, nucleophilic attack and subsequent ring closure yielding 5-exo-trig furobenzopyranone. Based on the comparison between possible paths, the diastereoselectivity of cis over trans and regio-divergence of 5-exo-trig over 7-endo-trig are both kinetically controlled for [2+2] and [3+2] cycloaddition in common. The positive solvation effect is suggested by decreased absolute and activation energies in chlorobenzene and chloroform solution compared with in gas. These results are supported by Multiwfn analysis on FMO composition of specific TSs, and MBO value of vital bonding, breaking.
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Open Access
Original Research Article
Article ID: 6267
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by Nan Lu, Chengxia Miao, Xiaozheng Lan
Therm. Sci. Eng. 2024 , 7(1);    3 Views
Abstract The mechanism is investigated for Rh(III)-catalyzed C-H alkenylation of enamide with enone and Rh(I)-catalyzed decarbonylative version of 1,2,3,4-tetrahydroquinoline with anhydride. The former contains β-C(sp 2 )−H activation of enamide, 1,2-migratory insertion of enone, β-hydride elimination or protodemetalation with additional HCl. The diastereoselectivity is kinetically controlled favoring alkenylation N-(2Z,4E)-butadiene while the regio-divergence is switchable to alkylation. The latter is composed of rate-limiting oxidative addition of anhydride to Rh(I), C8-selective C–H activation after ligand exchange producing tBuCO 2 H and six-membered rhodacycle, decarbonylation releasing CO as new carboxylate ligand and reductive elimination of Rh-alkenyl precursor leading to C8-alkenylated product. The whole process with huge heat release is favorable thermodynamically and all barriers capable to overcome under microwave assistance. The positive solvation effect is suggested by decreased absolute and activation energies in solution compared with in gas. These results are supported by Multiwfn analysis on FMO composition of specific TSs, and MBO value of vital bonding, breaking.
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Open Access
Review Article
Article ID: 5842
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by Reza Joia, Meiram Atamanov, Kuanysh Umbetkaliev, Mohammad Hamid Mohammadi, Sayed Reza Sarwari, Taibullah Modaqeq
Therm. Sci. Eng. 2024 , 7(1);    102 Views
Abstract Carbon based materials are really an integral component of our lives and widespread research regarding their properties was conducted along this process. The addition of dopants to carbon materials, either during the production process or later on, has been actively investigated by researchers all over the world who are looking into how doping can enhance the performance of materials and how to overcome the current difficulties. This study explores synthesis methods for nitrogen-doped carbon materials, focusing on advancements in adsorption of different pollutants like CO 2 from air and organic, inorganic and ions pollutants from water, energy conversion, and storage, offering novel solutions to environmental and energy challenges. It addresses current issues with nitrogen-doped carbon materials, aiming to contribute to sustainable solutions in environmental and energy sciences. Alongside precursor types and synthesis methods, a significant relationship exists between nitrogen content percentage and adsorption capacity in nitrogen-doped activated carbon. Nitrogen content ranges from 0.64% to 11.23%, correlating with adsorption capacities from 0.05 mmol/g to 7.9 mmol/g. Moreover, an electrochemical correlation is observed between nitrogen atom increase and specific capacity in nitrogen-doped activated carbon electrodes. Higher nitrogen percentage corresponds to increased specific capacity and capacity retention. This comprehensive analysis sheds light on the potential of nitrogen-doped carbon materials and highlights their significance in addressing critical environmental and energy challenges.
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