Fangjun Luan^1,2,3, Xuewen Mu^1,2,3, Shuai Yuan^1,2,3,*

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 695-712, 2024, DOI:10.32604/cmc.2024.048502

Abstract Online Signature Verification (OSV), as a personal identification technology, is widely used in various industries. However, it faces challenges, such as incomplete feature extraction, low accuracy, and computational heaviness. To address these issues, we propose a novel approach for online signature verification, using a one-dimensional Ghost-ACmix Residual Network (1D-ACGRNet), which is a Ghost-ACmix Residual Network that combines convolution with a self-attention mechanism and performs improvement by using Ghost method. The Ghost-ACmix Residual structure is introduced to leverage both self-attention and convolution mechanisms for capturing global feature information and extracting local information, effectively complementing whole and local signature features and mitigating… More >

DIPESHKUMAR D. KACHHADIYA, Z.V.P. MURTHY^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 49-61, 2021, DOI:10.32381/JPM.2021.38.1-2.5

Abstract The conventional process for methanol-water separation like distillation consumes about 60 % of total energy. As an alternative, researchers have developed a membrane-based separation process for alcohol-water mixtures separation. However, there is a big challenge for researches to separate alcohol-water aqueous mixtures using a polymeric membrane because of swelling. In the present work, the aim is to separate methanol from water by pervaporation using polymeric membranes made up of polyvinylidenefluroide (PVDF) and polyethylene glycol (PEG200) modified PVDF membranes. The membranes were characterized by thermogravimetry analysis (TGA), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FTIR). A study on… More >

Umer Sadiq Khan^1,2,*, Zhen Liu^1,2,*, Fang Xu^1,2, Muhib Ullah Khan^3,4, Lerui Chen⁵, Touseef Ahmed Khan^4,6, Muhammad Kashif Khattak⁷, Yuquan Zhang⁸

CMC-Computers, Materials & Continua, Vol.78, No.3, pp. 3323-3348, 2024, DOI:10.32604/cmc.2024.046094

Abstract Image classification and unsupervised image segmentation can be achieved using the Gaussian mixture model. Although the Gaussian mixture model enhances the flexibility of image segmentation, it does not reflect spatial information and is sensitive to the segmentation parameter. In this study, we first present an efficient algorithm that incorporates spatial information into the Gaussian mixture model (GMM) without parameter estimation. The proposed model highlights the residual region with considerable information and constructs color saliency. Second, we incorporate the content-based color saliency as spatial information in the Gaussian mixture model. The segmentation is performed by clustering each pixel into an appropriate… More >

Kenneth M. Armijo, Van P. Carey^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3003

Abstract This paper investigates the impact of Marangoni phenomena for low concentrations of 2-propanol/water and methanol/water mixtures. In real systems the addition of small levels of surface-active contaminants can affect the surface tension of the liquid-vapor interface and thermodynamic conditions in this region. Analysis was performed for three widely accepted binary mixture correlations to predict heat flux and superheat values for subatmospheric experimental data using bulk fluid and film thermodynamic properties. Due to the non-ideal nature of these alcohol/water mixtures, this study also employs an average pseudo single-component (PSC) coefficient in place of an ideal heat transfer coefficient (HTC) to improve… More >

Aravind Sathyanarayana^a, Pramod Warrier^b, Yogendra Joshi^a,*, Amyn Teja^b

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3007

Abstract Electrical and chemical compatibility requirements of electronic components pose significant constraints on the choice of liquid coolants. Dielectric coolants such as Novec fluids and fluoroinerts are plagued by poor thermal properties. This necessitates the development of new heat transfer fluids. In this study we examine mixture formulations that provide an avenue for enhancing the properties of existing heat transfer fluids. Mixture formulations of Novec fluid (HFE 7200) with Methanol and Ethoxybutane are considered. Pool boiling experiments are performed on a copper nanowire surface. The results show an improvement of 24% and 11% in the CHF of HFE 7200 – Methanol… More >

Morteza Eslamian^*

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-20, 2011, DOI:10.5098/hmt.v2.4.3001

Abstract Recent advances in thermodiffusion (Soret effect) in binary and higher multicomponent liquid mixtures are reviewed. The mixtures studied include the hydrocarbon, associating, molten metal and semiconductor, polymer, and DNA mixtures. The emphasis is placed on the theoretical works, particularly models based on the nonequilibrium thermodynamics, although other approaches such as the statistical, kinetic and hydrodynamic approaches are discussed as well. For each mixture, the major theoretical and experimental works are discussed and the research trends and challenges are addressed. Some of the challenges include a need for combining various methods to develop a comprehensive theoretical model or at least to… More >

Qianqian Shao¹, Min Wang^2,*, Nuo Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1337-1356, 2024, DOI:10.32604/cmes.2023.044313

Abstract To investigate the influences of co-flow and counter-flow modes of reactant flow arrangement on a proton exchange membrane fuel cell (PEMFC) during start-up, unsteady physical and mathematical models fully coupling the flow, heat, and electrochemical reactions in a PEMFC are established. The continuity equation and momentum equation are solved by handling pressure-velocity coupling using the SIMPLE algorithm. The electrochemical reaction rates in the catalyst layers (CLs) of the cathode and anode are calculated using the Butler-Volmer equation. The multiphase mixture model describes the multiphase transport process of gas mixtures and liquid water in the fuel cell. After validation, the influences… More >

Etim S. Udoetok^*

Frontiers in Heat and Mass Transfer, Vol.4, No.2, pp. 1-5, 2013, DOI:10.5098/hmt.v4.2.3008

Abstract A model for the coefficient of thermal conductivity of binary mixtures of gases has been derived. The theory presented is based on the assumption of random fluctuations between two possible extreme arrangements of a binary gas mixture. The results obtained from the new model compared favorably with published experimental results. The proposed new model provides a simple approach without sacrificing much accuracy compared to previous models. It is applicable to any binary mixture of gases which includes monoatomic gas mixture, polyatomic gas mixtures and mixtures involving rare gases. The new model can be very useful in analysis like combustion where… More >

Zan Wu^a, Zhaozan Feng^b, Bengt Sundén^a,*, Lars Wadsö^c

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-10, 2014, DOI:10.5098/hmt.5.18

Abstract Thermal conductivity and rheology behavior of two aqueous nanofluids, i.e., alumina and multi-walled carbon nanotube (MWCNT) nanofluids, were experimentally investigated and compared with previous analytical models. Information about the possible agglomeration size and interfacial thermal resistance in the nanofluids were obtained and partially validated. By incorporating the effects of interfacial thermal resistance, a revised model was found to accurately reproduce the experimental data based on the agglomeration size extracted from the rheology analysis. In addition, the thermal conductivity change of the alumina/water nanofluid with elapsed time was investigated. Thermal conductivity measurements were also conducted for alumina/water and MWCNT/water nanofluid mixtures. More >

Junjie Chen^*, Longfei Yan, Wenya Song

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-6, 2014, DOI:10.5098/hmt.5.16

Abstract To understand the effect of different thermal conductivities on catalytic combustion characteristics, effect of thermal conductivity on micro-combustion characteristics of hydrogen-air mixtures in Pt/γ-Al₂O₃ catalytic micro-combustors were investigated numerically with detailed chemical kinetics mechanisms. Three kinds of wall materials (100, 7.5, and 0.5 W/m·K) were selected to investigate the effect of heat conduction on the catalytic combustion. The simulation results indicate that the catalytic reaction restrains the gas phase reaction in Pt/γ-Al₂O₃ catalytic micro-combustors. The gas phase reaction restrained by Pt/γ-Al₂O₃ catalysts is sensitive to thermal boundary condition at the wall. For most conditions, the gas phase reaction cannot be… More >