Article
Biotechnology & Applied Microbiology
Kefu Wang, Kangkang Wang, Siqi Liang, Changyan Guo, Wei Wang, Jide Wang
Summary: The extensive use of plastic products by people has led to the prevalence of microplastics in aquatic and terrestrial ecosystems, which undergo multiple aging processes and release organic matter, thus affecting the ecosystem. This thesis systematically studied the photo-aging properties of PVC and the changes in physicochemical properties. The composition and fluorescence characteristics of microplastics leachate were also characterized. The study found that the O/C ratio can quantitatively characterize the surface aging of microplastics. Regression equations were established to predict the equilibrium adsorption capacity of aging microplastics.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2023)
Article
Engineering, Marine
Yu Qiu, Wei Shen, Renjun Yan, Xiaobin Li, Zhenzhou Ye, Mengzhen Li, Kang Liu, Kai Qin
Summary: This paper develops theoretical and numerical calculation methods to better predict the characteristics of bimodal sandwich composites, which is significant for structural design and safety check of marine sandwich composites.
Article
Engineering, Multidisciplinary
A. Amiri-Hezaveh, H. Moghaddasi, M. Ostoja-Starzewski
Summary: A new finite element scheme is proposed to analyze the elastodynamics of materials with interactions between electrical and mechanical fields. The scheme utilizes a new form of weighted residual and a specific spatial-temporal shape function, and reduces integral forms to algebraic equations for high accuracy analysis at arbitrary time intervals.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Mechanics
Benlong Su, Shouyao Liu, Peng Zhang, Jian Wu, Youshan Wang
Summary: This study compared the experimental and simulation results of the mechanical properties of overlap structure in cord-rubber composite, introducing a cohesion zone model to analyze the failure mechanism. The errors in simulating the limit load of the overlap structure were found to be about 5%. Interlaminar damage evolution was identified as key in the strength of the overlap structure, providing a theoretical basis for design of cord-rubber composites.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Marine
Kefeng Jiao, Feihong Yun, Zheping Yan, Gang Wang, Peng Jia, Liquan Wang, Dong Liu, Xiaoquan Hao
Summary: By optimizing the structural parameters of the rubber packer, the sealing performance of the subsea retractable connector can be significantly improved. The study utilized response surface optimization method and multi-objective genetic algorithm, introduced the anti-shoulder extrusion variable as a constraint, and ultimately achieved the optimization of the rubber packer's sealing performance.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Environmental
Chao Wang, Sijia Liang, Lihua Bai, Xinyue Gu, Xin Jin, Zeyu Xian, Bing Wu, Yong Sik Ok, Kan Li, Rui Wang, Huan Zhong, Cheng Gu
Summary: This study identified the impact of photo-aged PVC-MPs on cephalosporin antibiotics transformation, with hydrogen bonding accelerating CFZ hydrolysis but having negligible effect on CFX degradation. The research also highlighted the potential role of aged PVC-MPs as catalysts in mediating antibiotic transformations, in addition to increasing adsorption capacity.
Article
Computer Science, Interdisciplinary Applications
Wei Zhang, Zhi-hao Zhong, Chong Peng, Wei-hai Yuan, Wei Wu
Summary: The study combines strain smoothing technique with GPU parallel computing to improve computational efficiency. New computation formulations are proposed to save memory space, and the method is validated through several benchmark problems. The capability of GPU-accelerated SPFEM in solving large-scale complicated problems is demonstrated by modeling the progressive failure of a long slope.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Engineering, Multidisciplinary
Narendra S. Nanal, Scott T. Miller, Jesse D. Thomas, Lucy T. Zhang
Summary: This study presents a computational framework for simulating shell structures interacting with fluids using the immersed approach. The approach captures the complex movement and motion of thin structures and allows non-intrusive coupling of independent fluid and shell finite element solvers. The method projects the shell structure to create a volumetric structure, enabling accurate and realistic loading and geometry.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Thermodynamics
Ahmed M. Khalil, Samira T. Rabie
Summary: A thermoplastic elastomeric blend of NBR and PVC loaded with Moringa oleifera leaf powder exhibited improved mechanical properties and significant antibacterial activities, with potential applications in biomedical and other fields.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Polymer Science
Shengwen Yin, Yu Bai, Feng Kong, Zhonggang Wang, Congcong Fang
Summary: Thermo-oxidative aging has a significant impact on the properties of rubber materials, leading to decreased fatigue life and safety hazards in air spring bags. This study proposes an interval parameter correlation model considering material uncertainty to accurately describe rubber crack propagation characteristics. An aging prediction model based on the Arrhenius equation is established to determine the variations in fatigue crack propagation parameters during rubber aging. The effectiveness and accuracy of the method are verified through comparison with test and prediction results under temperature spectrum. It can guide fatigue reliability analyses of air spring bags.
Article
Mathematics, Interdisciplinary Applications
Josef Arthur Schoenherr, Patrick Schneider, Christian Mittelstedt
Summary: A new family of hybrid/mixed finite elements optimized for numerical stability is introduced. The elements show significant advantages in numerical robustness in a representative benchmark test.
COMPUTATIONAL MECHANICS
(2022)
Article
Engineering, Civil
Nasser Firouzi, Anil Misra
Summary: A nonlinear finite element formulation for large deformation analysis of hyperelastic membranes in Total Lagrangian framework is developed. Both invariant-based and stretch-based formulations are developed, and they are completely general and not restricted to axisymmetric loading and geometry of membrane. The developed formulations can handle both incompressible and compressible materials as well as isotropic and anisotropic materials. The comparison between different methods demonstrates the effectiveness of the stretch-based method derived in this paper.
THIN-WALLED STRUCTURES
(2023)
Article
Mechanics
Alp Sik, Ercan Gurses, Baris Sabuncuoglu
Summary: The embedded element method is a reliable and efficient way to analyze the mechanical behavior of composite materials. A new procedure has been developed to address the redundant volume problem in the embedded region, taking into account matrix nonlinearity. Results show that this procedure accurately predicts the behavior of constituents.
COMPOSITE STRUCTURES
(2021)
Article
Construction & Building Technology
Eslam El-Seidy, Matteo Sambucci, Mehdi Chougan, Mazen J. Al-Kheetan, Ilario Biblioteca, Marco Valente, Seyed Hamidreza Ghaffar
Summary: This study investigates the feasibility of using recycled rubber and PVC aggregates to replace natural sand in alkali-activated materials (AAMs) and evaluates the performance of the developed AAMs. Results show that AAM composites with PVC and rubber particles outperform natural aggregate composites in terms of thermal resistivity, water absorption, volume permeability voids (VPV), and high-frequency sound insulation.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Engineering, Civil
Yachong Xu, Yan Zhuge, Md. Rajibul Karim, Reza Hassanli, Md. Mizanur Rahman, Martin Freney
Summary: This paper used a combined finite and discrete element method to investigate the structural performance of tyre walls built with tyre-encased-soil elements. The numerical model was verified against experimental results, providing a deeper understanding of the tyre wall behavior. The results encourage the adoption of tyre walls in low-rise building constructions, solving tyre recycling/storage issues and promoting sustainable construction practices.
ENGINEERING STRUCTURES
(2023)
Article
Chemistry, Analytical
Dan Dobrota, Sever-Gabriel Racz, Mihaela Oleksik, Ionela Rotaru, Madalin Tomescu, Carmen Mihaela Simion
Summary: The objective of this research was to design intelligent tools that can control tool vibrations and improve the roughness of processed surfaces. The study showed that the designed intelligent tools perform well in processing aluminum alloys and are not affected by cooling-lubrication fluids.
Article
Chemistry, Physical
Dan Dobrota, Mihaela Oleksik, Anca Lucia Chicea
Summary: Optimizing the machining process for aluminum bronze alloy can reduce energy consumption and improve surface roughness. The research showed that using a specific cutting tool variant can reduce power consumption by approximately 30% and decrease roughness of the processed surface by approximately 90-100%.
Article
Chemistry, Physical
Karmveer, Naveen Kumar Gupta, Md Irfanul Haque Siddiqui, Dan Dobrota, Tabish Alam, Masood Ashraf Ali, Jamel Orfi
Summary: Artificial roughness on the absorber of the solar air heater improves performance but requires higher pumping power. Thermo-hydraulic performance considers both pumping power and heat gain. The shape, size, and arrangement of artificial roughness are crucial for performance optimization.
Article
Business
Alina Daniela Voda, Gabriela Dobrota, Dan Dobrota, Danut Dumitru Dumitrascu
Summary: This paper examines the issue of fiscal sustainability in EU member states and identifies the necessary fiscal policy instruments. Using empirical analysis, it finds a direct relationship between economic growth and private investment.
JOURNAL OF BUSINESS ECONOMICS AND MANAGEMENT
(2022)
Article
Chemistry, Physical
Aditya Vatsa, Tabish Alam, Md Irfanul Haque Siddiqui, Masood Ashraf Ali, Dan Dobrota
Summary: Numerical study on microchannels with a two-sided wedge shape at the base was conducted, and it was found that the microchannel with a wedge angle of 15 degrees demonstrated better thermohydraulic performance.
Article
Chemistry, Analytical
Nikita Kumari, Tabish Alam, Masood Ashraf Ali, Anil Singh Yadav, Naveen Kumar Gupta, Md Irfanul Haque Siddiqui, Dan Dobrota, Ionela Magdalena Rotaru, Abhishek Sharma
Summary: This study investigates a novel design of microchannel heat sink (MCHS) and explores the impact of different surface modifications on heat transfer performance. The results demonstrate that geometric modifications significantly enhance the cooling capacity, highlighting the importance of effective thermal management for electronic devices.
Article
Engineering, Chemical
Jatoth Heeraman, Ravinder Kumar, Prem Kumar Chaurasiya, Naveen Kumar Gupta, Dan Dobrota
Summary: The aim of this research is to study the heat transfer and friction factor in a double-pipe heat exchanger using twisted tape with dimples. The study investigated the effect of different dimple diameters and a uniform diameter-to-depth ratio on heat transmission and friction factor properties. The results showed that the addition of dimples on the twisted tape is an excellent and cost-effective approach to improve heat transfer in heat exchangers.
Article
Thermodynamics
Raghav Singupuram, Tabish Alam, Masood Ashraf Ali, Saboor Shaik, Naveen Kumar Gupta, Nevzat Akkurt, Mukesh Kumar, Sayed M. Eldin, Dan Dobrota
Summary: This paper presents a novel design of microchannel heat sinks (MHS) that can effectively cool electronic components and maintain its temperature in the safe range. Circular extruding ribs were added on the side wall of the passage to enhance heat transfer. The study found that the maximum Nusselt number was observed at sector angles of 80 degrees, with values ranging from 7.26 to 64.11. The thermohydraulic performance parameter (THPP) values were greater than one, indicating the proposed design is reasonable and effective for thermal management of MHS.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Construction & Building Technology
Mehmet Ali Kallioglu, Ahmet Yilmaz, Ashutosh Sharma, Ahmed Mohamed, Dan Dobrota, Tabish Alam, Rohit Khargotra, Tej Singh
Summary: The study investigates the impact of different insulation materials and fuel types on the cooling and heating performance of buildings in various climatic conditions in India. The study evaluates potential parameters for expanded polystyrene and extruded polystyrene insulation materials across different locations. The results show that optimal insulation thickness, annual savings, and payback period vary depending on the cooling and heating requirements.
Review
Multidisciplinary Sciences
Rohit Khargotra, Raj Kumar, Rahul Nadda, Sunil Dhingra, Tabish Alam, Dan Dobrota, Anca Lucia Chicea, Kovacs Andras, Tej Singh
Summary: Heat transfer in water using solar energy is an effective way to utilize renewable energy and reduce dependence on non-renewable sources. Utilizing turbulent promoters is an efficient solution to enhance heat exchanger performance. This review summarizes experimental and numerical studies on heat exchangers, including thermal examinations and fluid flow characteristics with different turbulent promoters and tube arrangements. It also compares the thermal performance of twisted tape configurations in heat exchanger tubes using correlations developed by different researchers.
Review
Polymer Science
Sergiu Lazar, Dan Dobrota, Radu-Eugen Breaz, Sever-Gabriel Racz
Summary: This research presents analyses on the eco-design of polymer matrix composite parts, addressing its definition, benefits, and importance in various stages of product development. It emphasizes the adoption of sustainable approaches in product design and manufacturing, with a focus on waste recycling technologies for these materials. The research promotes eco-design as an essential strategy for sustainable and responsible production, inspiring companies to adopt these principles for the benefit of the environment and their business performance.
Article
Thermodynamics
Anil Kumar, Masood Ashraf Ali, Rajesh Maithani, Naveen Kumar Gupta, Sachin Sharma, Sunil Kumar, Lohit Sharma, Robin Thakur, Tabish Alam, Dan Dobrota, Sayed M. Eldin
Summary: This research paper presents an experimental analysis on a heat exchanger tube using a newly designed perforated conical ring combined with twisted tape as inserts. The investigation analyzes various geometric and flow parameters and establishes empirical correlations for the Nusselt number and the friction factor.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Rajesh Maithani, Anil Kumar, Masood Ashraf Ali, Naveen Kumar Gupta, Sachin Sharma, Tabish Alam, Sayed M. Eldin, Javed Khan Bhutto, Dan Dobrota, Florin Cristian Ciofu
Summary: This numerical study explores a modified solar heat collector with wavy delta winglets as turbulent promoters. The winglets disrupt the viscous layer, improving heat transfer in the rectangular channel. The analysis considers parameters such as pitch, number of waves, and flow angle of attack. The study finds that a specific combination of parameters achieves a maximum exergy efficiency of 29.18%.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Shashank Pal, Anil Kumar, Masood Ashraf Ali, Naveen Kumar Gupta, Shyam Pandey, Praveen Kumar Ghodkhe, Swapnil Bhurat, Tabish Alam, Sayed M. Eldin, Dan Dobrota
Summary: Chemical recycling of MMPW is a feasible method to reduce plastic waste and recover energy products, especially liquid. Pyrolysis at 550 degrees C can produce high-grade plastic oil with a yield of 69.8 wt%. Engine tests showed that increasing the proportion of plastic oil in diesel fuel increased cylinder pressure and net heat release rate, but decreased brake thermal efficiency. Emissions such as CO, HC, and NOx were higher for plastic oil blends, while CO2 and smoke opacity were reduced compared to reference diesel.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Review
Multidisciplinary Sciences
Fisal Asiri, Md Irfanul Haque Siddiqui, Masood Ashraf Ali, Tabish Alam, Dan Dobrota, Radu Chicea, Robert Daniel Dobrota
Summary: A mathematical model has been developed to study myocyte contraction in the human cardiac muscle. The interactions of various parameters in the heart muscle have been explored numerically, and the Land model provides a good platform for analyzing the active contraction of human cardiac myocytes.