G. Prakash Narayan^a, Karan H. Mistry^a, Mostafa H. Sharqawy^a, Syed M. Zubair^b, John H. Lienhard V^a,†

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-13, 2010, DOI:10.5098/hmt.v1.2.3001

Abstract Simultaneous heat and mass exchange devices such as cooling towers, humidifiers and dehumidifiers are widely used in the power generation, desalination, air conditioning, and refrigeration industries. For design and rating of these components it is useful to define their performance by an effectiveness. In this paper, several different effectiveness definitions that have been used in literature are critically reviewed and an energy based effectiveness which can be applied to all types of heat and mass exchangers is defined. The validity and the limitations of the various effectiveness definitions are demonstrated by way of several examples including direct and indirect contact,… More >

Bengt Sundén^*, Jinliang Yuan

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-20, 2010, DOI:10.5098/hmt.v1.1.3008

Abstract Depending on specific configuration and design, a variety of physical phenomena is present in fuel cells, e.g., multi-component gas flow, energy and mass transfer of chemical species in composite domains and sites. These physical phenomena are strongly affected by chemical/electrochemical reactions in nano-/micro-scale structured electrodes and electrolytes. Due to the electrochemical reactions, generation and consumption of chemical species together with electric current production take place at the active surfaces for all kinds of fuel cells. Furthermore, water management and twophase flow in proton exchange membrane fuel cells (PEMFCs) and internal reforming reactions of hydrocarbon fuels in solid oxide fuel cells… More >

Moran Wang^a, Bin-Yang Cao^b, Zeng-Yuan Guo^b,*

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-8, 2010, DOI:10.5098/hmt.v1.1.3004

Abstract The thermomass theory regards heat owning mass-energy duality, exhibiting energy-like features in conversion and mass-like features in transfer processes. The equivalent mass of thermal energy is determined by the mass-energy equivalence of Einstein, which therefore leads to the inertia of heat in transfer. In this work, we build up a thermomass gas model based on this theory to describe the fluid-flow-like heat conduction process in a medium. The equation of state and the governing equations for transport for the thermomass gas have been derived based on methodologies of the classical mechanics since the drift speed of thermomass gas is generally… More >

Yamixa Delgado^1,*, Caliani Gaytan¹, Naydi Perez², Eric Miranda³, Bryan Colón Morales¹, Mónica Santos¹

Congenital Heart Disease, Vol.19, No.1, pp. 19-31, 2024, DOI:10.32604/chd.2024.046339

Abstract Background: Given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States, there is a compelling need to investigate the intricate interplay among body mass index (BMI), pregestational, and gestational maternal diabetes, and their potential impact on the occurrence of congenital heart defects (CHD) during neonatal development. Methods: Using the comprehensive System of Vigilance and Surveillance of Congenital Defects in Puerto Rico, we conducted a focused analysis on neonates diagnosed with CHD between 2016 and 2020. Our assessment encompassed a range of variables, including maternal age, gestational age, BMI, pregestational diabetes, gestational diabetes, hypertension,… More >

Muthasim Fahmy^†, Zhifa Sun

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-14, 2011, DOI:10.5098/hmt.v2.4.3003

Abstract A gas-liquid solute transfer process initiated in a closed vessel can exhibit Rayleigh-Bénard-Marangoni (RBM) convection enhanced mass transfer. For short exposure times experimental and theoretical results demonstrate that for deep liquid systems prior to solute penetration across the depth of the fluid, the stability thresholds of the system decreases with time. For thin liquid layers at longer exposure times the mass transfer enhancement under RBM convection can be affected in two ways: (1) solute penetration to the bottom liquid-solid boundary causing a departure from a penetration type concentration profile; (2) solute penetration to the top gas-solid boundary in the gas… More >

S.W. Igo^a,*, D.J. Bathiébo^b, K. Palm^a, K. N’wuitcha^c, B. Zeghmati^d, X. Chesneau^d

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-7, 2011, DOI:10.5098/hmt.v2.3.3007

Abstract A combined heat and mass transfer in laminar forced convection flow in a rectangular venturi tube have been numerically simulated. A transformation has been used to transform the irregular profile of the venturi walls into a straight line. Transfers equations are solved using finite volume method, Gauss and Thomas algorithms. The influences of venturi effect, inlet Reynolds number and venturi diameter ratio on the heat and mass transfer are discussed in detail. Results presented as pressure gradient, Nusselt and Sherwood numbers profiles, velocity patterns and isotherms show that the throat play an important role on the heat an mass transfer… More >

Q.X. Wu^a, Y.L. He^b, T.S. Zhao^a,b,*

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-14, 2011, DOI:10.5098/hmt.v2.3.2001

Abstract Running direct methanol fuel cells (DMFC) with concentrated fuel is desirable to maximize the specific energy of the fuel cell system and to improve the performance by mitigating the water flooding problem associated with diluted methanol operation. This article provides a comprehensive review of recent advances in understanding mass transport phenomena in DMFCs operating with concentrated fuel. The review starts with elaborating the key issues of mass transport of reactants and products associated with highly-concentrated methanol operation, followed by summarizing and discussing past experimental and numerical investigations into the effects of the membrane electrode assembly (MEA) design, flow field structure… More >

Hae Sung Park¹, Yong Suk Choi^2,*

Computer Systems Science and Engineering, Vol.48, No.2, pp. 451-477, 2024, DOI:10.32604/csse.2023.043245

Abstract Much like humans focus solely on object movement to understand actions, directing a deep learning model’s attention to the core contexts within videos is crucial for improving video comprehension. In the recent study, Video Masked Auto-Encoder (VideoMAE) employs a pre-training approach with a high ratio of tube masking and reconstruction, effectively mitigating spatial bias due to temporal redundancy in full video frames. This steers the model’s focus toward detailed temporal contexts. However, as the VideoMAE still relies on full video frames during the action recognition stage, it may exhibit a progressive shift in attention towards spatial contexts, deteriorating its ability… More >

Arpit Jain¹, Nageswara Rao Moparthi¹, A. Swathi², Yogesh Kumar Sharma¹, Nitin Mittal³, Ahmed Alhussen⁴, Zamil S. Alzamil^5,*, MohdAnul Haq⁵

Computer Systems Science and Engineering, Vol.48, No.2, pp. 341-362, 2024, DOI:10.32604/csse.2023.036973

Abstract Recently, the coronavirus disease 2019 has shown excellent attention in the global community regarding health and the economy. World Health Organization (WHO) and many others advised controlling Corona Virus Disease in 2019. The limited treatment resources, medical resources, and unawareness of immunity is an essential horizon to unfold. Among all resources, wearing a mask is the primary non-pharmaceutical intervention to stop the spreading of the virus caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) droplets. All countries made masks mandatory to prevent infection. For such enforcement, automatic and effective face detection systems are crucial. This study presents a face… More >

Gintautas Miliauskas^*, Stasys Sinkunas, Kristina Norvaisiene, Kestutis Sinkunas

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-6, 2012, DOI:10.5098/hmt.v3.2.3006

Abstract Water droplet evaporation process is numerically modelled under various heat and mass transfer conditions. Regularities of heat transfer process interaction are examined. Modelling in this work was performed using the combined analytical – numerical method to investigate heat and mass transfer in the two-phase droplets-gas flow system. The influence of forced liquid circulation on the thermal state of droplets is taken into account by the effective coefficient of thermal conductivity. Calculating the rate of droplet evaporation and the intensity of convective heating, the influence of the Stefan’s hydrodynamic flow is taken into account. Balancing energy fluxes in the droplet to… More >