Hasil untuk "Mechanical industries"

Jasmine Garland, Kyri Baker, Ben Livneh et al.

Energy burden, the ratio of energy expenditure to household income, is a critical yet often overlooked measure of economic and environmental inequality in the United States. A high energy burden, 6% or greater, is not just a financial issue; it is a public health and environmental justice concern, as frontline communities often experience greater exposure to pollution, poorer housing efficiency, and heightened vulnerability to extreme weather events. This study uses self-organizing maps (SOMs), an unsupervised neural network, to identify contributing factors and inform policy interventions for energy-burdened communities in the North, South, Midwest, and West census regions, a novel use of this method. It is also among the first to integrate environmental justice indicators, including outdoor air quality metrics and health disparities, as determinants of energy burden. In addition to environmental justice indicators, socioeconomic status, building characteristics, and power outages are explored to assist policymakers, engineers, and advocates working within the energy transition. Results revealed statistically significant ( p  < 0.05) differences in these indicators across SOM-defined energy-burden regimes. For the Midwest and South regions, all 45 indicators showed statistical significance, while 44 were significant in the Northeast, and 41 were significant for the West. These findings suggest that high energy-burden regimes tend to coincide with elevated environmental and health risk indicators, which may intensify under climate change.

Treerat Vacharanukrauh, Apinan Soottitantawat, Nuttha Thongchul et al.

Bioethanol plays a crucial role in the global transition to sustainability, serving as a renewable fuel especially in the transportation sector, and a versatile renewable chemical precursor in industries, mitigating greenhouse gas (GHG) emissions. Although bioethanol is renewable, its production is still carbon-intensive, with most emissions arising from fermentation and cogeneration. Despite significant advancements, existing works on bioethanol have largely focused on individual decarbonization elements (e.g., CCU, CCS in bioenergy, and process intensification in ethanol production). Few studies link these strategies together to show how they could collectively move bioethanol toward carbon-negative production. This review aims to fill that gap by systematically analyzing the evolution of bioethanol production processes, identifying key sources of CO2 emissions, and critically evaluating state-of-the-art strategies—including process optimization, CCU, and CCS—within a unified framework. Overall, this review underscores that integrating process optimization, CCU, and CCS can transform bioethanol production from a low-carbon fuel into a negative-emission technology, reinforcing its pivotal role in global decarbonization efforts.

Jun Wang, Lei Wang, Ding Wang et al.

Abstract With the global energy structure shifting towards clean and efficient hydrogen energy, the safety management issues of hydrogen refueling stations are becoming increasingly prominent. To address these issues, a hydrogen leak localization algorithm for hydrogen refueling stations based on a combination of reinforcement learning and hidden Markov models is proposed. This method combines hidden Markov model to construct a probability distribution model for hydrogen leakage and diffusion, simulates the propagation probability of hydrogen in different grid cells, and uses reinforcement learning to achieve fast and accurate localization of hydrogen leakage events. The outcomes denoted that the training accuracy reached 95.2%, with an F1 value of 0.961, indicating its high accuracy in hydrogen leak localization. When the wind speed was 0.8 m/s, the mean square error of the raised method was 0.03, and when the wind speed was 1.0 m/s, the mean square error of the raised method was 0.04, proving its good robustness. After 50 localization experiments, the proposed algorithm achieves a localization success rate of 93.7% and an average computation time of 42.8 s, further demonstrating its high accuracy and computational efficiency. The proposed hydrogen leakage location algorithm has improved the accuracy and efficiency of hydrogen leakage location, providing scientific basis and technical guarantee for the safe operation of future hydrogen refueling stations.

Ramin Mehdipour, Behnam Feizollah Beigi, Romina Fathiraboki et al.

In hot seasons, residential areas consume significant amounts of electricity for refrigeration and air conditioning, leading to peak power consumption. This simultaneous increase in cooling load, combined with reduced performance of gas turbines, places considerable stress on the power grid, particularly during specific periods each year. Cold storage systems offer an effective solution by shifting electricity consumption from peak daytime hours to off-peak nighttime periods. This study evaluates and compares the economic and thermal performance of cold storage systems implemented in both power plants and office buildings for peak demand management. Tailored cold storage systems were designed for each application, with a focus on ensuring reliable performance during peak cooling demand based on load analysis. The study utilized real-world case studies, including modeling for an office building in Arak, Iran, and a nearby power plant, to understand the impact of different climatic conditions on system performance. The results indicate that, during peak hours, the turbine’s net power output improved by 15.98% and 17.97% with partial and full storage methods, respectively, compared to scenarios without cooling. Additionally, the economic analysis revealed substantial cost savings, with partial and full storage systems resulting in reductions of 97.36% and 95.54%, respectively, in power plant units compared to similar office buildings with equivalent power consumption. The analysis also highlights that full storage systems in both office and power plant contexts deliver better peak shaving performance but at a higher cost due to the larger size of tanks and equipment required for operation. These findings underscore the potential of cold storage systems as an effective strategy for enhancing electricity management and reducing operational costs.

Md Shafayet-Ul-Islam, Abdul Kuddus, Md Kabiruzzaman et al.

Copper-based chalcogenide quaternary semiconductors have emerged as promising candidates for next-generation photovoltaic (PV) devices, owing to their unique electronic and photonic properties coupled with environmentally friendly compositions. This study explores the potential of copper-based absorber materials, specifically Cu2FeSnS4 (CFTS), as an absorber in heterojunction solar cells with Cu-/Ni-metal oxides back surface field (BSF) and SnS2 buffer layers using the SCAPS-1D Simulator. Initially, we assess the performance of CFTS-absorber solar cells and compare the key photovoltaic metrics with those of other Cu-based semiconductors including CuInxGa(1-x)Se2 (CIGS), Cu2ZnSnS4 (CZTS), Cu2CoSnS4 (CCTS), Cu2NiSnS4 (CNTS), Cu2BaSnS4 (CBTS), Cu2MnSnS4 (CMTS), to identify the most promising absorber. Subsequently, we optimize the layer properties, including active layer thickness, free-carrier concentration, bulk and interface defect density, and carrier recombination in potential CFTS. Further, we examine the impact of defects, and carrier recombination, including radiative, Shockley-Read-Hall (SRH), and Auger recombination. These detailed studies yield improved and competitive photoconversion efficiency, (PCE) of 27.31% (compared to 24.68%, without BSF) with open circuit voltage, (VOC) of 1.36 V, short-circuit current density, (JSC) of 22.28 mA/cm² and fill factor, (FF) of 90.47% for Cu2O, whereas the PCE of 26.97% with VOC of 1.07 V, JSC of 28.82 mA/cm² and FF of 86.91% for NiOx BSF layer in Au/Mo/BSF(Cu2O and NiOx)/CFTS/SnS2/ZnMgO/ZnO:Al/Pt configurations under optimized conditions. The enhanced charge separation and carrier collection efficiencies reveal the strong potential of CFTS absorber heterostructures with Cu2O/NiOx, SnS2, and bi-layer ZnMgO/ZnO:Al as BSF, buffer, and window layers, repectively, providing insights and resources for developing high-efficiency CFTS-based photovoltaic devices.

Ben Reza Awang, Wahyono Wahyono

Karlo Špelić, Mario Panjičko, Gregor Drago Zupančić et al.

Abstract In response to the EU's REPowerEU initiative (COM (2022) 108) which encourages an increase in biogas production by 20% in member states by 2030 to boost energy independence, it has become essential to identify sustainable alternatives to traditional feedstocks for biogas production, especially in the EU Member states where there is still high dependence on corn silage as the main raw material in biogas plants. While corn silage, predominantly used in the European biogas plants today, serves primarily for the livestock sector, alternative sources need to be explored. Therefore, this study aimed to evaluate the potential of Arundo donax, a perennial energy crop, as an alternative feedstock in a continuous anaerobic process. The biogas yield and its quality, characterized by CH4, CO2, H2S and O2 content, were determined during a continuous process with A. donax, compared with two mixed feedstocks of A. donax and corn silage over a 5‐month period in a continuous anaerobic digestion process. The results revealed that A. donax exhibits a biogas yield and methane content comparable to corn silage, indicating its potential as a viable and sustainable alternative feedstock for biogas production.

Xudong Ma, Yuting Wu, Yanjun Du et al.

Abstract Steam generating heat pump (SGHP) is a key technology for industrial decarbonization. For comprehensive evaluation of the feasibility and reliability of SGHP in different industrial sector, the work develops a thorough evaluation model for assessing the performance of SGHP by considering waste heat recovery, CO2 trading value, and pollutant emission cost, in addition to the conventional evaluation criteria. This work presents a thorough comparison of the thermodynamic performance and sustainability of various types of SGHPs across different industrial sector. Additionally, the conflicting relationships between the coefficient of performance (COP) and exergy efficiency are balanced through the application of the technique for order preference by similarity to ideal solution (TOPSIS). The results show that all the indexes of SGHP connected to an open heat pump (SGHPO) with different application scenarios are higher than those of SGHP connected to a flash tank (SGHPF). At the most unfavorable operating condition of the system, the COP minimum value is 1.31 and the exergy efficiency minimum value is 20.42%. These results indicate that replacing the coal-fired boiler with SGHP is feasible and the work could provide theoretical guidance for optimal design and equipment manufacture.

Raghvendra Kumar Mishra, Kartikey Verma, Deepa sethi singh

Defects in nanomaterials have emerged as a pivotal aspect influencing their properties and diverse applications across numerous industries. This comprehensive review explores the intricate relationship between defects, primarily in carbon nanotubes and graphene, and their implications across a spectrum of applications. Beginning with an introduction delving into the significance and types of defects, the review elucidates their multifaceted impact on the mechanical, electrical, and environmental characteristics of these nanomaterials. It presents detailed analyses of studies exploring defects in carbon nanotubes and graphene, shedding light on their effects on mechanical and electrical properties, alongside characterizing methods. The paper meticulously examines the extensive array of applications involving carbon nanotubes and graphene, encompassing electronics, biomedical advancements, and considerations for environmental sustainability. Furthermore, it systematically incorporates studies highlighting the implications of defects on these applications. This review precisely examines defect engineering in nanomaterials across various industries, emphasizing the nuanced role of defects in tailoring properties for specific applications. It concludes by summarizing the integral role defects play in shaping the future of nanomaterial applications in diverse industries.

Jannis Langer, Francesco Lombardi, Stefan Pfenninger et al.

Indonesia has large renewable energy resources that are not always located in regions where they are needed. Sub-sea power transmission cables, or island links, could connect Indonesia’s high-demand islands, like Java, to large-resource islands. However, the role of island links in Indonesia’s energy transition has been explored in a limited fashion. Considering Indonesia’s current fossil fuel dependency, this is a critical knowledge gap. Here we assess the role of island links in Indonesia’s full power sector decarbonisation via energy system optimisation modelling and an extensive scenario and sensitivity analysis. We find that island links could be crucial by providing access to the most cost-effective resources across the country, like onshore photovoltaics (PV) and hydropower from Kalimantan and geothermal from Sumatera. In 2050, 43 GW of inter-island transmission lines enable 410 GW _p of PV providing half of total generation, coupled with 100 GW of storage, at levelised system costs of 60 US$(2021)/MWh. Without island links, Java could still be supplied locally, but at 15% higher costs due to larger offshore floating PV and storage capacity requirements. Regardless of the degree of interconnection, biomass, large hydro, and geothermal remain important dispatchable generators with at least 62 GW and 23% of total generation throughout all tested scenarios. Full decarbonisation by 2040 mitigates an additional 464 MtCO _2 e compared to decarbonisation by 2050, but poses more challenges for renewables upscaling and fossil capacity retirement.

Hongna Qiao, Xiaohui Yu, Weiqiang Kong et al.

Energy storage is a crucial solution for the intermittency and instability of renewable energy. Carnot batteries, a novel electrical energy storage technology, promise to address the challenges of renewable electrical energy storage worldwide. Rankine-based Carnot batteries, which are geographically unconstrained and effectively store energy at low temperatures, have attracted considerable attention in recent years. In this study, a mathematical model was developed, and a multi-objective optimization with power-to-power-efficiency, exergy efficiency, and levelized cost of storage was performed. Moreover, the investment cost and exergy loss of the optimized system components were investigated in detail and analyzed. The results showed that the optimal power-to-power-efficiency, exergy efficiency, and levelized cost of the storage system can be achieved at 60.3%, 33%, and 0.373 $/kWh based on single-objective optimization, and the operating parameters of the proposed system are different. Therefore, there is a strong trade-off relationship between the three objective functions mentioned above. Under the same weighting for the two approaches, they are 25.8%, 23%, and 0.437 $/kWh, and 39.3%, 29.1%, and 0.549 $/kWh, respectively. Furthermore, this study observed that the exergy destruction in the charge mode was nearly 95 kW larger than that in the discharge mode, and the exergy destruction of the throttle valve was the largest at 95.83 kW, accounting for 28.32%. The expander was the component with the highest cost (35.84% of the total cost) in the proposed system, followed by the compressor.

Tianshu Song, Junkai Wang, Xiyao Xu et al.

Abstract Straw returning has been demonstrated as a beneficial approach for the utilization of renewable biomass source, which contributes to reducing environmental pollution and strengthening the sustainability of agriculture. However, information on how microorganisms respond to different straw return modes (SRMs) at varying nitrogen fertilizer levels (NFLs) in the black soil is still limited. The community composition, network pattern, and modular function of bacteria and fungi are investigated under three SRMs, including straw removal (CK), crushed straw incorporation (SD), and biochar incorporation (BC) at three NFLs (0, 144, and 240 kg N ha−1, respectively) mainly using Illumina MiSeq technique based on a long‐term maize field experiment. Results showed that bacterial richness, diversity, and fungal richness decreased with NFL reduction. However, these decreases can be compensated by SD and BC, demonstrating superiority for BC at reduced NFLs. SD and BC differed in their effects on the bacterial and fungal abundances (showing increments only in SD) and fungal Shannon diversity (remaining stable only in BC irrespective of NFLs). Microbial communities were substantially affected by SRMs and interacted with NFLs, which were driven by soil NH4+‐N, available potassium, total nitrogen, and pH. In addition, SD induced a network characterized by its highly complex (average degree 10.259 vs. 3.364) and stable structure (average clustering coefficient 0.503 vs. 0.239), Ascomycota as predominating keystone taxa, and abundant N‐cycling related bacteria, while BC formed a network comprising a superior modular structure (modularity 2.599 vs. 0.912), dominant symbiotic fungi, and soil bulk density as specific shaping factor, indicating that network pattern, keystone taxa, modular function, and determining factors shifted between SD and BC co‐occurrence networks. These results deepen insights into the response divergence of bacteria and fungi to SRMs and NFLs, providing a scientific basis for selecting the suitable strategy for sustainable straw utilization in the black soil area.

O.M. , O.A. , H.M.

The article highlights the trend of increasing demand for industrial robotics in mechanical assembly industries in recent years. A brief analytical review of PP for the automated solution of problems of industrial robotics in mechanical assembly productions of machine and instrument engineering was performed. A critical analysis of the most common PPs was carried out regarding their functional capabilities in the technological preparation of robotic systems, supported operating systems, auxiliary software, and the price component. The above information is summarized in the form of a table, which indicates the presence of the main analyzed possibilities of PP. The results of a critical analysis of the most well-known PP based on available information sources regarding functionality and application options at the stages of planning, design, programming of robotic systems showed that at the moment there is no universal PP or software solution that can meet modern production requirements. Positive trends in the application show open source PPs, which provide flexibility in application, but require the user to be highly qualified in robotics and programming, but even they do not guarantee the complete solution of tasks of scientific research and engineering content.

Donald S Christian, Anjela D Christian

Workplace health and safety has been of paramount importance for any nation and the stakeholders- authorities, employers and workers – must have reasonable sensitization for the same. During the COVID 19 pandemic, lots of policy formulations and regulations had to incorporate within the industries for the health and welfare of the workers. The “new normal” will take some time for adjustments, challenges and implications to be implemented effectively and consistently. Certain processes in the workplace, especially in the mechanical engineering companies, are likely for high close contact incidences. Special situations pertaining to workers’’ health, like crowded accommodations, travel risks as well common canteens, all need to be reconsidered for providing safer environment to the workers, as far as the current pandemic is concerned. This requires coordinated efforts from all the stakeholders within the mechanical field through subconscious acceptance of the norms of safety and hygiene at all levels.

Mikhailo Sukach

Проведено шосту міжнародну науково-практичну конференцію Transfer of Innovative Technologies 2020, присвячену 90-річчю від дня заснування Київського національного університету будівництва і архітектури. Особливістю цьогорічного форуму було те, що він відбувався дистанційно на платформі Cisco Webex за участі науковців з Польщі, Франції, Австралії, Іраку, Лівії, Бразилії, Китаю. Фахівці в галузях будівництва і архітектури, інженерії та екології, інформаційних технологій та ін. традиційно ділились своїм досвідом. Роботу було спрямовано на інтеграцію українських і закордонних фахівців і наукових шкіл у розробці теорії проведення досліджень, створення нових методів і техніки, практичне застосування енергоощадних, екологічно безпечних технологій та засобів. Мета конференції – спілкуваня з фахівцями різних галузей для вирішення глобальних проблем ресурсного та енергетичного забезпечення виробництва, передачі інноваційних технологій у різні сфери людської діяльності. Офіційними мовами конференції є українська, російська, англійська, польська і французька. Було отримано понад сотню заявок від 140 учасників з наукових та освітніх закладів, промисловості, недержавних установ, студентів, магістрантів та аспірантів. Було представлено понад три десятки інноваційних проектів в галузях архітектури, інженерії споруд, інформаційних технологій, кібербезпеки тощо. Обговорено результати дослідження двох докторських та кількох кандидатських дисертацій. За результатами оголошенних конкурсів в номінаціях Інноваційний проект, Презентація, Публікація визначено переможців 2020 року, які були нагороджені дипломи. Найактивніші учасники з числа фахівців та студентської молоді отримали Подяки і Сертифікати. Результати роботи та препринти найкращих презентацій авторів опубліковано у Збірнику матеріалів конференції (online) та журналі Transfer of Innovative Technologies. КНУБА налагодив співпрацю зі спеціалістами Університету науки і техніки Цзянсу (Китай), Університету прикладних наук та мистецтв (Fachhochschule Dortmund, Germany), IT університету Астани (Казахстан) у галузях досліджень досліджень та видавничої справи. Учасники конференції підтримали Петицію керівництва Міжнародного центру інтегральної екології CEI Laudato Si (Варшава) до Папи Римського і Президента США про антропогенний вплив на світове середовище і захист від академічного насилля та тиску.

Abdulhalim Musa Abubakar, Kiman Silas, Mohammed Modu Aji et al.

Kinetic study of microorganism’s growth in chicken manure (CM) when producing biogas is often studied for scale-up purposes. CM are considered as waste, and can cause serious environmental consequences when not properly disposed. The objective of the study is to know the characteristics of the bioreactor condition or environment responsible for CM degradation and biogas production. Methods involves serial dilution, pour plating, cell count and the determination of Monod parameters. POLYMATH regression results shows that CM of particle density 0.0163 g/cm3 gives a maximum specific growth rate, ?_max of 0.007316 hr^(-1) and half saturation constant, K_s of 3.8×?10?^8mg/l which points to substrate sufficiency for the survival of microorganisms and biogas production.

Shaofeng Wei, Xiaoyi Liu, Jiao Xie et al.

Greenly synthesized silver nanoparticles (AgNPs) on different cellulosic materials show tremendous potential for colorful, biocidal, and reasonably strong products by replacing the traditional chemical-based synthesis protocols. This study reports on a novel in situ synthesis protocol for synthesizing green and sustainable AgNPs over cellulosic kraft paper substrates using a bio-based stabilizing agent (Cephalotaxus harringtonia fruit extract). The protocol could play a significant role in packaging industries. The aqueous extracts of Cephalotaxus harringtonia fruits have been used to synthesize the metallic silver. The deposited AgNPs values were investigated through XRF (X-ray fluorescence) analysis. The number of deposited nanoparticles (NPs) was 268 ± 7, 805 ± 14, and 1,045 ± 16 PPM, respectively for 0.5, 1.5, and 2.5 mm silver precursors. The developed products were tested with SEM (scanning electron microscopy), SEM-mediated elemental mapping, EDX (energy disruptive X-ray), FTIR (Fourier transform infrared spectroscopy), and XRD (X-Ray diffraction). XRD analysis further confirmed the presence of peaks for elemental AgNP on the deposited papers. Colorimetric values were measured to confirm the colorful appearances of the developed metallic silvers. Mechanical properties were tested in terms of the tensile index and bursting index. Moreover, the statistical analysis of coefficient of variations (R2) and a post-hoc ANOVA test that adopted the Newman-Keul methodology also confirm the significance of developed nanoparticles in the papers. The shielding capacity against UV light was also investigated; all the AgNPs-treated products provided values higher than 40, demonstrating the strong UV resistance capability of the kraft paper material. Overall, the study confirms a successful development of green AgNPs on paper materials.

Jari Lyytimäki, Nina A. Nygrén, Anna Pulkka et al.

Abstract Background Media coverage can play an important part in energy transitions. It creates awareness of landscape-level megatrends affecting energy systems. It influences and is influenced by public and policy agendas on a regime level. On a niche level, it can spread or screen out information and motivate or discourage actors to adopt new technologies and practices. However, relatively few studies have specifically addressed the role of media in energy transitions. Newspaper coverage of biogas is studied here as a case of media framing of a potential renewable energy solution. Methods This article examines the long-term development of newspaper coverage of biogas in Finland. The aim of the quantitative content analysis is to draw an overall picture of the main phases of biogas coverage of a widely read newspaper focusing on agriculture and forestry, actors using discursive power in this coverage and key framings of the discussion. The results are discussed from the perspective of energy transition studies. In particular, future expectations created by the media are explored. Results The results show a lack of newspaper coverage on biogas in the early 2000s, followed by a rapid increase and stabilisation of the volume of newspaper coverage. Biogas was most often mentioned as a secondary topic of broader discussions related to renewable energy. The core discussion focusing on biogas was characterised by very positive framings of biogas as a preferable energy solution fully compatible with the principle of circular economy. The news stories often had a strong future orientation, and examples of enthusiastic forerunners were frequently presented. However, the coverage also emphasised the poor economic profitability of biogas technologies and a need for considerable public subsidies that are inherently unpredictable. Conclusions The future of niche-level energy technologies such as biogas can be strongly shaped by information flows, public perceptions and expectations created in part by media coverage. The analysed newspaper coverage in Finland was ambivalent from the perspective of energy transition. On the one hand, biogas production was represented as a preferable, environmentally friendly niche-level energy technology that should be encouraged. On the other hand, by emphasising the economic unviability of biogas technologies, the analysed newspaper coverage did not promote the adoption of biogas.

Yuanbing Zhou, Xing Chen, Xin Tan et al.

The challenge of global warming has become a driving force for a global energy transition. The Global Energy Interconnection (GEI) is a modern energy system aimed at meeting the global power demand in a clean and green manner. With the development of clean replacement, electricity replacement, and grid interconnection strategies, GEI contributes to the global temperature control by dramatically reducing the level of energy-related CO2 emissions. This study proposes an integrated framework for analyzing the mechanism of CO2 emission reduction via GEI implementation. The obtained results demonstrate that the total cumulative contribution of GEI to mitigating the effects of CO2 emissions (estimated by conducting a scenario analysis) corresponds to a total reduction of 3100 Gt CO2. The contributions of the clean replacement, electricity replacement, and carbon capture and storage GEI components to this process are equal to 55, 42, 5%, respectively. Using GEI, the utilization of clean energy in 2050 will increase by a factor of 4.5 at an annual growth rate of 4.4%, and the electrification rate will be 2.4 times greater than the current one. Keywords: Global Energy Interconnection, CO2 emission reduction, clean replacement, electricity replacement, grid interconnection

Qiang Gao, Jilin Chen, Li Wang et al.

Motion control of gun barrels is an ongoing topic for the development of gun control equipments possessing excellent performances. In this paper, a typical fractional order PID control strategy is employed for the gun control system. To obtain optimal parameters of the controller, a multiobjective optimization scheme is developed from the loop-shaping perspective. To solve the specified nonlinear optimization problem, a novel Pareto optimal solution based multiobjective differential evolution algorithm is proposed. To enhance the convergent rate of the optimization process, an opposition based learning method is embedded in the chaotic population initialization process. To enhance the robustness of the algorithm for different problems, an adapting scheme of the mutation operation is further employed. With assistance of the evolutionary algorithm, the optimal solution for the specified problem is selected. The numerical simulation results show that the control system can rapidly follow the demand signal with high accuracy and high robustness, demonstrating the efficiency of the proposed controller parameter tuning method.