Article
Chemistry, Physical
Xudong Chen, Yutao Ji, Jiajun Yang, Dong Yan, Lichao Jia, Xiaotao Han, Kaiming Wu, Jian Li
Summary: A bottom-access structure stack was developed to enhance the integration of the SOFC stack module and facilitate assembly. Computational fluid dynamics techniques were used to optimize the gas distribution, and the results showed that introducing guide plates and distributors improved flow distribution near the inlet. Increasing the buffer chamber height greatly improved flow distribution uniformity, while excessive height had the opposite effect.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Raj Kumar, A. Veeresh Babu, Shirish H. Sonawane
Summary: This article proposes a novel rhombohedral interconnector with a staggered position to enhance heat and mass transport behavior in anode-supported solid oxide fuel cells (SOFCs). The rhombohedral staggered interconnector design alters fluid flow patterns, improves power density by 33.9%, and helps control pressure distribution in flow channels. Comparisons with a traditional rectangular interconnector model and parametric research with varied mass flow rates are conducted to validate the improved performance of the rhombohedral design. The findings suggest that the proposed interconnector configuration is essential for optimal SOFC operation.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Nicholas J. Williams, Ieuan D. Seymour, Dimitrios Fraggedakis, Stephen J. Skinner
Summary: In this study, the activation losses at solid oxide fuel cell (SOFC) electrodes were investigated by simulating charge transfer using density functional theory (DFT). The electrostatic responses to the electric field were found to correlate with experimental data for different reduction reactions at mixed ionic-electronic conducting (MIEC) electrode surfaces. The study also highlighted the importance of decoupled ion-electron transfer and charged adsorbates on the performance of electrodes under nonequilibrium conditions. The findings have potential implications in energy storage and catalysis.
Article
Energy & Fuels
Bora Timurkutluk, Emre Ucar
Summary: This study focuses on the performance based parametric optimization of flow channels in SOFCs through numerical simulations. Results show that rib width is the most effective parameter on cell performance, while different channel depths have almost no impact on cell performance.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Wenchuan Liu, Dengwei Jing
Summary: By using molecular dynamics methods, this study investigates droplet transport on hydrophobic surfaces under a rotating electric field, revealing its rolling mode and high-speed stability under certain conditions. The study also analyzes the influence of electric field strength and rotational angular frequency on droplet transport, and demonstrates the programmability of the driving method to achieve complex droplet trajectories.
Article
Thermodynamics
Changkun Hao, Zezhi Zeng, Bingguo Zhao, Yuping Qian, Weilin Zhuge, Yuqing Wang, Yixiang Shi, Yangjun Zhang
Summary: This study investigates the effect of heat generation management on reducing the temperature gradient in a micro-tubular solid oxide fuel cell. It compares the performance of the cell with tubular separators and flanged separators, showing that both can effectively reduce the temperature gradient, but flanged separators lead to a more uniform temperature profile. The study also proposes a spatial temperature gradient diagram to evaluate the influence of different geometric parameters on the overall performance, revealing that the length of the flanged separator is the primary factor affecting cell performance.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Marine
Yiyang Hu, Haisheng Zhao, Wei Shi, Chunwei Bi, Xin Li
Summary: A three-dimensional numerical model for the UHMWPE cage was established, revealing the flow field characteristics of both internal and external flows. The study found that the degree of deceleration decreases as the flow velocity increases, but this effect becomes less apparent when the flow velocity reaches a certain threshold. Furthermore, the study compared the flow field characteristics of double cages with different spacing and multiple cages with equal spacing.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Physical
Xingyu Xiong, Kao Liang, Guiliang Ma, Liming Ba
Summary: This study establishes a three-dimensional multi-physics model for the Solid Oxide Fuel Cell (SOFC) stack using a two-step coupling method based on the BP neural network. Compared with the traditional fully coupled model, the novel model shows significant advantages in accuracy and computational resource requirements. The simulation of planar SOFC 50-cell stacks and 150-cell stack towers demonstrates that the flow uniformity of the stack towers decreases by more than 30% compared to the 50-cell stack, resulting in significant deterioration of voltage and temperature distribution. The optimization of the manifold and buffer area parameters and the channel height of the stack tower achieves better uniformity of flow and voltage distribution and lower temperature gradient simultaneously.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Yong Zhang, Shirong He, Xiaohui Jiang, Mu Xiong, Yuntao Ye, Xi Yang
Summary: A PEMFC single cell model with waveform staggered flow field is established in this study. The simulation results show that the proposed flow field design effectively solves the uneven gas concentration and cathode flooding issues, significantly improving the performance of the fuel cell.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Mechanics
G. Karlsson, C. Fureby, L. Wang, C. Norberg, M. Holm, F. Stroemer
Summary: In this study, large eddy simulation (LES) is used to investigate the convectively dominated heat transfer in a corrugated heat exchanger channel. Visualization techniques are employed to elucidate the unsteady flow and heat transfer processes. A comparison between LES and Reynolds-averaged Navier-Stokes simulations reveals significant differences. Furthermore, different grid resolution requirements are found for the flow and heat transfer processes in LES.
Article
Engineering, Chemical
Yinxiang Xu, Junbo Xu, Huizhou Liu, Chao Yang
Summary: Pumping fluids at the nanoscale is crucial for nanofluidic systems. This study demonstrates the possibility of using non-uniform electric fields to induce continuous and unidirectional net flow of water confined in nanochannels through molecular dynamics simulations and the extended Navier-Stokes (ENS) equation. The net flow is a result of the combination of the unidirectional orientation of water molecules and the net force induced by the electric field intensity difference. Higher flow rates can be achieved by enhancing the electric field intensity gradients. The ordered arrangements of water molecules in electric fields make electropumping more effective than pressure-driven flow. The proposed ENS equation is more applicable to flows with high order degree of water molecules.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Energy & Fuels
Raj Kumar, A. Veeresh Babu, Shirish H. Sonawane
Summary: A trapezoidal interconnector design for solid oxide fuel cells (SOFCs) is proposed and compared with the conventional rectangular interconnector (CRI) configuration. The results show that the trapezoidal design increases power density and allows for lower operating temperature in SOFCs. The width of the rib on the anode side has a moderate effect on fuel transport.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Costas Athanasiou, Christos Drosakis, Gaylord Kabongo Booto, Costas Elmasides
Summary: This study evaluates the economic feasibility of biogas-SOFCs for combined heat and power (CHP) generation, compared to conventional biogas-CHP with internal combustion engines (ICEs). The results indicate that the size of the SOFC and the feasibility criterion significantly impact the economic evaluation of the system.
Article
Chemistry, Physical
A. Hamrang, M. Abdollahzadeh, A. Moradi Bilondi, F. Bagherighajari, S. M. Rahgoshay, J. C. Pascoa
Summary: This study compares the performance of a PEMFC with conventional parallel serpentine flow fields and parallel serpentine-baffled flow fields. The results show that the PSBFF design can significantly improve cell performance, especially at higher pressure, temperature, and stoichiometric ratio.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Fatemeh Bagherighajari, Abbas Ramiar, Mohammadmahdi Abdollahzadehsangroudi, Jose Carlos Pascoa, Paulo J. Oliveira
Summary: This paper aims to study the performance of fuel cells using an interdigitated flow field with intermediate channel blocks on the cathode side. The results show that the interdigitated flow fields with middle blocks can increase reactant transfer, reaction rate, and removal of liquid water in the fuel cell. Compared to the parallel flow field, the different types of interdigitated flow fields increase the net power of the fuel cell.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Clinical Neurology
Hani Chanbour, Lakshmi Suryateja Gangavarapu, Jeffrey W. Chen, Gabriel A. Bendfeldt, Iyan Younus, Mahmoud Ahmed, Steven G. Roth, Leo Y. Luo, Silky Chotai, Amir M. Abtahi, Byron F. Stephens, Scott L. Zuckerman
Summary: This study aims to investigate the incidence of unplanned readmission, identify associated risk factors, and determine the impact of unplanned readmission on long-term outcomes in patients undergoing surgery for cervical spine metastases. The results showed that 15% of patients experienced unplanned readmission, with 33% for surgical reasons and 67% for medical reasons. Preoperative radiation was associated with increased unplanned readmission rate, but readmission had no association with overall survival or local recurrence.
WORLD NEUROSURGERY
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Adam D. Yock, Mahmoud Ahmed, Sarah Masick, Manuel Morales-Paliza, Christien Kluwe, Ashwin Shinde, Austin Kirschner, Eric Shinohara
Summary: This study analyzed the clinical experience of CBCT-based daily online adaptive radiotherapy and demonstrated the impact of adaptive triggers on dosimetric and procedural outcomes. The results showed that daily online adaptive radiotherapy improved target coverage in multiple pelvic treatment sites, while the improvement in organ-at-risk metrics was randomly distributed.
JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS
(2023)
Article
Mechanics
Ahmed Elhanafy, Yasser Abuouf, Samir Elsagheer, Shinichi Ookawara, Mahmoud Ahmed
Summary: Diagnostic technology based on magnetic fields is commonly used in medicine, but exposure to strong electromagnetic fields has adverse effects on patients. This study investigates the effects of external uniform magnetic fields on blood flow in healthy and diseased cases, and determines safe values for field strength. A three-dimensional non-Newtonian flow model is developed to investigate the effects of the magnetic field on shear rate and hematocrit. Numerical simulations are conducted at different field strengths and orientations, and results demonstrate the dominant effect of the magnetic field in the Y-direction.
Article
Clinical Neurology
Hani Chanbour, Jeffrey W. Chen, Lakshmi S. Gangavarapu, Gabriel A. Bendfeldt, Matthew E. LaBarge, Mahmoud Ahmed, Steven G. Roth, Silky Chotai, Leo Y. Luo, Amir M. Abtahi, Byron F. Stephens, Scott L. Zuckerman
Summary: This is a retrospective case-control study that aimed to identify risk factors associated with unplanned readmission after metastatic spine surgery and determine its impact on long-term outcomes. The results showed that postoperative complications were associated with unplanned readmission, and 3-month unplanned readmission was associated with a shorter time to local recurrence and decreased overall survival.
Editorial Material
Pharmacology & Pharmacy
Mahmoud Ahmed, Deok Ryong Kim
FRONTIERS IN PHARMACOLOGY
(2023)
Article
Genetics & Heredity
Mahmoud Ahmed, Hyun Joon Kim, Deok Ryong Kim
Summary: The human genome project ignited scientific interest in an ambitious goal, leading to significant discoveries and a new era of research. The project's impact extended beyond its results, as novel technologies and analysis methods emerged, making high-throughput datasets more accessible to labs and serving as a model for future collaborations. To effectively utilize these datasets for research and public benefit, re-analysis, curation, and integration with other data forms are crucial.
FRONTIERS IN GENETICS
(2023)
Article
Medicine, General & Internal
Mahmoud Ahmed, Yamini Krishna, Petya Popova, Rose Herbert, Gediminas Sidaras, Anshoo Choudhary, Stephen B. B. Kaye
Summary: This study examined the impact of low-dose propofol sedation on patient reported outcome measures (PROMS) during cataract surgery. The study found that the use of low-dose propofol was associated with reduced pain, needle recall, and blood pressure. The results suggest that propofol can be an effective sedation method for cataract surgery.
JOURNAL OF CLINICAL MEDICINE
(2023)
Review
Medicine, General & Internal
Alfredo Borgia, Vito Romano, Davide Romano, Luca Pagano, Aldo Vagge, Giuseppe Giannaccare, Mahmoud Ahmed, Kunal Gadhvi, Nardine Menassa, Mohammad Ahmad, Stephen Kaye, Giulia Coco
Summary: Astigmatism is a common issue after keratoplasty, and it is important to accurately identify and characterize its type, amount, and direction. Various techniques, including corneal tomography and topo-aberrometry, can be used for evaluation, but alternative methods are available if these instruments are not accessible. This article describes both low-tech and high-tech approaches for detecting post-keratoplasty astigmatism, as well as the management strategies involving suture manipulation.
JOURNAL OF CLINICAL MEDICINE
(2023)
Article
Genetics & Heredity
Dalal Al-Sharshani, Dinesh Velayutham, Muthanna Samara, Reham Gazal, Ayman Al Haj Zen, Mohamed A. Ismail, Mahmoud Ahmed, Gheyath Nasrallah, Salma Younes, Nasser Rizk, Sara Hammuda, M. Walid Qoronfleh, Thomas Farrell, Hatem Zayed, Palli Valapila Abdulrouf, Manar AlDweik, John Paul Ben Silang, Alaa Rahhal, Rana Al-Jurf, Ahmed Mahfouz, Amar Salam, Hilal Al Rifai, Nader I. Al-Dewik
Summary: This study aimed to investigate the association between selected single nucleotide polymorphisms (SNPs) and dyslipidemia, as well as the increased susceptibility risks of cardiovascular diseases, type 2 diabetes mellitus, and non-alcoholic fatty liver disease. The results showed significant differences in genotypic frequencies of six SNPs between dyslipidemia patients and control individuals. These differences were found to be associated with gender, obesity, hypertension, and diabetes.
MOLECULAR GENETICS & GENOMIC MEDICINE
(2023)
Article
Thermodynamics
Mohamed M. Elsabahy, Mohamed Emam, Hidetoshi Sekiguchi, Mahmoud Ahmed
Summary: Characteristic performance maps (CPMAPs) are developed to solve the tradeoff between electrical generation and thermal utilization in solar cell systems. Several variables related to thermal, energy, and exergy are obtained using a validated thermo-fluid model. The findings show that maximizing the electrical exergy efficiency suggests non-concentrated solar cells with moderate cooling, while maximizing power generation requires high concentration ratios and reduced heat sink temperature. Maximizing overall exergy efficiency depends on the combination of concentration ratio and heat transfer coefficient based on the application temperature demand.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Oncology
Trang Huyen Lai, Mahmoud Ahmed, Jin Seok Hwang, Md Entaz Bahar, Trang Minh Pham, Jinsung Yang, Wanil Kim, Rizi Firman Maulidi, Dong-Kun Lee, Dong-Hee Kim, Hyun Joon Kim, Deok Ryong Kim
Summary: Breast cancer is a common tumor type in women with a high fatality rate due to metastasis. Raf kinase inhibitory protein (RKIP) is a potential metastasis suppressor candidate, but its expression is reduced or lost in aggressive cancer variants. This study explores the role of RKIP as an anti-metastatic gene using two breast cancer cell lines with different levels of RKIP expression. The findings suggest a potential strategy to reverse the metastatic capability of breast cancer cells by chemically manipulating RKIP expression.
FRONTIERS IN ONCOLOGY
(2023)
Article
Mathematics, Applied
Naeem Ahmad, E. S. Kamel, Sid Ahmed Ould Ahmed Mahmoud
Summary: In this work, we extend the concept of n-quasi-p-isometric operators from a single operator to multi-dimensional operators. We present new interesting results of these tuples of operators, which expand upon recently published works that focus on a single operator.
Article
Mining & Mineral Processing
Khaled Yassin, Mahmoud Ahmed, Mohamed Gamal Eldin Khalifa, Ayman Aly Hagrass
Summary: Dry magnetic separation is an effective technique for reducing iron in feldspar, especially in arid regions with limited water resources. This study conducted dry magnetic separation experiments on feldspar ore in the Wadi Umm Harjal area in Egypt, successfully removing iron content and improving the quality of the sample to meet industry specifications.
ARCHIVES OF MINING SCIENCES
(2023)
Article
Multidisciplinary Sciences
Sid Ahmed Ould Ahmed Mahmoud, Naeem Ahmad
Summary: In this paper, new classes of operators related to polynomially normal operators are introduced. The first class is m-quasi polynomially normal operators, which includes polynomially normal operators studied in recent papers. A bounded linear operator S is said to be an m-quasi polynomially normal operator if there exists a nontrivial polynomial P and a natural number m satisfying a certain equation. The second class is called polynomially C-normal operators, which includes C-normal operators studied in other papers. An operator S is called a polynomially C-normal operator if there exists a nontrivial polynomial P and a conjugation operator C satisfying a certain equation. The paper presents a detailed study of certain properties of the first class of operators and gives an introduction to the second class.
IRANIAN JOURNAL OF SCIENCE
(2023)
