M. Gh. Mohammed Kamil^1,*, M. S. Kassim¹, R. A. Mahmood^2,3, L. AZ Mahdi⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.4, pp. 985-998, 2022, DOI:10.32604/fdmp.2022.018938

Abstract This work investigates the steam condensation phenomena in an air-cooled condenser. The considered horizontal flattened tube has a 30 mm hydraulic diameter, and its length is a function of the steam quality with a limit value between 0.95 and 0.05. The mass flow rate ranges from 4 to 40 kg/m².s with a saturated temperature spanning an interval from 40°C to 80°C. A special approach has been implemented using the Engineering Equation Solver (EES) to solve a series of equations for the two-phase flow pattern and the related heat transfer coefficients. A wavy-stratified structure of the two-phase flow has been found when… More >

Chin-Shyurng Fahn¹, Chang-Yi Kao^2,*, Meng-Luen Wu³, Hao-En Chueh⁴

Computer Systems Science and Engineering, Vol.42, No.2, pp. 451-463, 2022, DOI:10.32604/csse.2022.022368

Abstract With the evolution of video surveillance systems, the requirement of video storage grows rapidly; in addition, safe guards and forensic officers spend a great deal of time observing surveillance videos to find abnormal events. As most of the scene in the surveillance video are redundant and contains no information needs attention, we propose a video condensation method to summarize the abnormal events in the video by rearranging the moving trajectory and sort them by the degree of anomaly. Our goal is to improve the condensation rate to reduce more storage size, and increase the accuracy in abnormal detection. As the… More >

Daoming Shen^1,2,*, Chao Gui¹, Jinhong Xia¹, Songtao Xue^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 489-500, 2020, DOI:10.32604/fdmp.2020.08969

Abstract The performances of a refrigeration unit relying on compressors working in parallel have been investigated considering the influence of the compressor volumetric efficiency and isentropic efficiency on the compression ratio. Moreover, the following influential factors have been taken into account: evaporation temperature, condensation temperature and compressor suction-exhaust pressure ratio for different opening conditions of the compressor. The following quantities have been selected as the unit performance measurement indicators: refrigeration capacity, energy efficiency ratio (COP), compressor power consumption, and refrigerant flow rate. The experimental results indicate that the system refrigeration capacity and COP decrease with a decrease in evaporation temperature, increase… More >

Maroua Ben Abdelkader^1,2,*, Nedra Azizi¹, Ayda Baffoun³, Yves Chevalier², Mustapha Majdoub¹

Journal of Renewable Materials, Vol.7, No.12, pp. 1347-1362, 2019, DOI:10.32604/jrm.2019.07926

Abstract Microencapsulation of neroline inside microcapsules having a polyurethane shell based on β-cyclodextrin (β-CD) and hexane diisocyanate was performed by interfacial polycondensation. The polyol nature of β-CD caused tight crosslinking of microcapsules wall. Microcapsules of neroline were characterized for their chemical composition and structure of the polyurethane shell by FTIR spectroscopy, thermogravimetric analysis, optical and electron microscopy, light scattering and electrophoresis measurements. Core content and encapsulation yield were 15% and 60%, respectively. Spherical microcapsules of mean diameter 29 μm were slightly cationic with an isoelectric point of 6.3. Neroline-loaded microcapsules were fixed on cotton fabric using an impregnation technique. The functionalized… More >

Jian Xie*, Cong Liang, Qingting She, Jinliang Xu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.3, pp. 157-157, 2019, DOI:10.32604/icces.2019.05222

Abstract Recently, micro/nano structured surfaces with various wettabilities have been developed to enhance condensation heat transfer. Here, two improved condensation heat transfer models were proposed to guide design of these surfaces. The first model deals with condensation on homogeneous wettability surface with nono-pillars. Compared with the classical model, the improved model behaves three features: (1) The linking from surface wettability to nano-pillars parameters is established; (2) The nano-porous thermal resistance under condensate droplets is considered; (3) The transition criteria of different droplet detachment modes including sliding, rolling and jumping is incorporated. The nano-pillars are found to have both positive and negative… More >

Shijun Zhao^1,2, Xiaoying Chen^1,3,*, Xiaolei Wang¹, Wenming Ji¹, Zhonghua Dai⁴

Journal of Quantum Computing, Vol.1, No.1, pp. 29-39, 2019, DOI:10.32604/jqc.2019.06112

Abstract The condensation process of dew droplets is influenced by many factors. A dew point condensation image observation system was built to improve the response speed of dew point detector under different measuring conditions. The basic mechanism of dew drop condensation growth was studied and the influence of various factors on the dew drop growth rate were analyzed. And the accuracy of the influence results was verified based on the improved Hough transform circle detection. The results show that the growth rate of dew droplets is affected by ambient temperature, dew point temperature, mirror temperature and air velocity. The observed variation… More >

F. J. Santiago-Medina¹, A. Pizzi^{1, 2*}, M. C. Basso¹, L. Delmotte³, S. Abdalla²

Journal of Renewable Materials, Vol.5, No.5, pp. 388-399, 2017, DOI:10.7569/JRM.2017.634142

Abstract The reaction of a desulphurized kraft lignin with hexamethylene diamine as a model of a polyamine has been investigated. For this purpose, guaiacol was also used as a lignin model compound and treated under similar conditions. Solid state CP-MAS 13C NMR, FTIR and MALDI-TOF spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic and aliphatic hydroxy groups of lignin. Simultaneously a second reaction leading to the formation of ionic bonds between the same groups occurred. These new reactions have been clearly shown to involve several phenolic and alcohol hydroxyl… More >

Lazhar Merouani¹, Belkacem Zeghmati², Azeddine Belhamri³

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 267-290, 2013, DOI:10.3970/fdmp.2013.009.267

Abstract The present work is a numerical study of laminar film condensation from vapor-gas mixtures in an inclined channel with an insulated upper wall and an isothermal lower wall coated with a thin porous material. A two-dimensional model is developed using a set of complete boundary layer equations for the liquid film and the steam-air mixture while the Darcy-Brinkman-Forchheimer approach is used for the porous material. The governing equations are discretized with an implicit finite difference scheme. The resulting systems of algebraic equations are numerically solved using Gauss and Thomas algorithms. The numerical results enable to determine the velocity, temperature and… More >

Rashed Al-Ajmi¹, Mohamed Mosaad^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 51-68, 2012, DOI:10.3970/fdmp.2011.008.051

Abstract Conjugate heat transfer across a vertical solid wall separating natural convection in a cold fluid-saturated porous medium and film condensation in a saturated-vapour medium is analyzed. The analysis reveals that this thermal interaction process is mainly controlled by the thermal resistance ratio of wall to porous-side natural convection and that of condensate film to natural convection. Asymptotic and numerical results of interest are obtained for the local and mean overall Nusselt number as functions of these two thermal resistance ratios. More >

Kilho Eom¹, Jeong-Hee Ahn², Seung-Chul Baek², Jae-In Kim², Sungsoo Na^2,3

CMC-Computers, Materials & Continua, Vol.6, No.1, pp. 35-42, 2007, DOI:10.3970/cmc.2007.006.035

Abstract This paper concerns the application and demonstration of robust reduction methodology for biomolecular structure modeling, which is able to estimate dynamics of large proteins. The understanding of large protein dynamics is germane to gain insight into biological functions related to conformation change that is well described by normal modes. In general, proteins exhibit the complicated potential field and the large degrees of freedom, resulting in the computational prohibition for large protein dynamics. In this article, large protein dynamics is investigated with modeling reduction schemes. The performance of hierarchical condensation methods implemented in the paper is compared with that obtained from… More >