Kyvia Pereira¹, Libardo V. Vanegas-Useche², Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 97-144, 2020, DOI:10.32604/cmc.2020.09862 - 20 May 2020

Abstract Fretting fatigue is a type of failure that may affect various mechanical components, such as bolted or dovetail joints, press-fitted shafts, couplings, and ropes. Due to its importance, many researchers have carried out experimental tests and analytical and numerical modelling, so that the phenomena that govern the failure process can be understood or appropriately modelled. Consequently, the performance of systems subjected to fretting fatigue can be predicted and improved. This paper discusses different aspects related to the finite element modelling of fretting fatigue. It presents common experimental configurations and the analytical solutions for cylindrical contact. More >

Ying Fang¹, Jianhua Wu^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 5-6, 2019, DOI:10.32604/mcb.2019.05695

Abstract For hemostasis and thrombosis, some proteins, such as Von Willebrand Factor (VWF, a multimeric plasma glycoprotein synthesized in endothelial cells and megakaryocytes and secreted to circulation or attached to endothelial cells), the metalloprotease ADAMTS13 (a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13), P-selectin (one of three selectin family members with a N-terminal C-type lectin domain, an epidermal growth factor (EGF)-like module, a series of consensus repeat (CR) units, a transmembrane segment and a short cyto-plasmic domain) and β2 integrin. In adhesion and aggregation of circulating platelets towards to the sites of… More >

Daniel Scida^1,*, Sébastien Alix¹, Stéphane Buet¹, El Hadi Saidane¹, François Courmont^1,2, Karim Behlouli², Rezak Ayad¹

Journal of Renewable Materials, Vol.7, No.9, pp. 865-875, 2019, DOI:10.32604/jrm.2019.06609

Abstract This work aims at studying the effect of hygrothermal and UV cyclic aging on the tensile properties and esthetic characteristics of non-woven composites. The composite materials were thermo-compressed from non-woven mats made up of PP and flax or kenaf fibers. This works included evaluating the change in color appearance and analyzing the variations in tensile properties and damage mechanisms, depending on the aging time. The presence of the UV protection film on the composite surface showed its effectiveness against aging. From visual observations and measurement of colorimetric parameters, it has been proved effective in the More >

Ying Zhou^1,*, Peng Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 759-777, 2019, DOI:10.32604/cmes.2019.04383

Abstract This paper proposes a novel three-dimensional (3D) isolation system for facilities and presents the numerical simulation approach for the isolated system under earthquake excitations and impact effect using the OpenSees (Open System for Earthquake Engineering Simulation) software frame work. The 3D isolators combine the quasi-zero stiffness (QZS) system in the vertical direction and lead rubber bearing in the horizontal direction. Considering the large aspect ratio of the isolated facility, linear viscous dampers are designed in the vertical direction to diminish the overturning effect. The vertical QZS isolation system is characterized by a cubic force-displacement relation,… More >

Ammar Abdulkadhim^a,*, Azher Mouhsen Abed^a , Khaled Al-Farhany^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-7, 2018, DOI:10.5098/hmt.11.12

Abstract The conjugate natural convection heat transfer in a partially heated porous enclosure had been studied numerically. The governing dimensionless equations are solved using finite element method. Classical Darcy model have been used and the considering dimensionless parameters are modified Rayleigh number (10 ≤ Ra ≤ 10³), finite wall thickness (0.02 ≤ D ≤ 0.5), thermal conductivity ratio (0.1 ≤ K_r ≤ 10), and the aspect ratio (0.5 ≤ A≤ 10). The results are presented in terms of streamlines, isotherms and local and average Nusselt number. The results indicate that heat transfer can be enhanced by increasing More >

M. Arun^a,*, M. Jose Prakash^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-10, 2018, DOI:10.5098/hmt.11.9

Abstract Prediction of heat transfer deterioration in rocket engine coolant channels with supercritical flow is essential while designing high pressure rocket engines. Three-dimensional conjugate heat transfer of cryogenic methane in rectangular engine cooling channels at supercritical pressures with asymmetric heating imposed on the bottom channel surface is numerically investigated, focusing on the effects of key parameters such as aspect ratio, heat flux and coolant pressure. Due to the similarity of the coolant channel with that of an actual rocket engine, the results obtained herein are beneficial for the design and optimization of rocket engine cooling systems.… More >

Felicit e Kamdem^1,2, Danielle Kedy Koum^2,3, Ba Hamadou^1,4, Melanie Yemdji¹, Henry Luma^1,4, Marie Solange Doualla^1,4, Diomède Noukeu⁵, Esther Barla⁵, Christophe Akazong⁵, Anastase Dzudie^1,4, Henry Ngote¹, Yves Monkam¹, Sidiki Mouliom¹, Samuel Kingue^4,6

Congenital Heart Disease, Vol.13, No.1, pp. 113-117, 2018, DOI:10.1111/chd.12529

Abstract Introduction: Cardiovascular diseases in pediatric pathologies have emerged in the recent years in sub-Saharan Africa (SSA), with congenital heart diseases (CHDs) being the most frequent. Unfortunately, their diagnosis is usually delayed, thereby increasing childhood morbidity and mortality.
Objectives: Describe the clinical, echocardiographic, and therapeutic aspects of CHDs of children at Douala General Hospital.
Methods: We carried out a cross-sectional descriptive study over a 10-year period, from January 2006 to December 2015. Files and reports of cardiac ultrasounds of patients aged ≤ 15 years were reviewed.
Results: We reviewed the medical records of 1616 children, of which 370 (22.9%) had… More >

M. Arun, J. Akhil, K. Noufal, Robin Baby, Darshitha Babu, M. Jose Prakash^*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-9, 2017, DOI:10.5098/hmt.8.23

Abstract The supercritical turbulent flow of cryogenic methane flowing in a rocket engine cooing channel is numerically analysed by imposing constant heat flux at the bottom surface of the channel. The calculation scheme is validated by comparing the results obtained with experimental results reported in literature. The heat transfer coefficient is influenced by the strong variation in thermophysical properties of methane at super critical pressure. An increasing trend in the average value of Nusselt number is observed with aspect ratio. The efficacy of both Modified Jackson and Hall and Bishop empirical correlations in predicting Nusselt number More >

Kaprawi Sahim^* , Dewi Puspitasari^†

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-6, 2017, DOI:10.5098/hmt.8.16

Abstract One row of heated elliptical cylinder with aspect ratio 0.6 and 0.8 are studied to know the forced heat transfer performance. The transversal distance between the cylinders are changed and the heat transfer is observed. Numerical observation of the study is done by using finite volume method to solve the momentum equations in two dimension domains. The pressure term instead of velocity is obtained by measurement in a subsonic wind tunnel and then it is injected into the momentum equation. The results of the hydrodynamic calculation are then injected into the energy equation which is… More >

Riitta Molarius¹, Pekka Tuomaala¹, Kalevi Piira¹, Minna Räikkönen¹, Christoph Aubrecht², Maria Polese³, Giulio Zuccaro^3,4, KaroliinaPilli-Sihvola⁵, Kalev Ranna

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.2, pp. 131-158, 2015, DOI:10.3970/cmes.2015.109.131

Abstract In northern regions, society can be seriously interrupted by a prolonged electricity network blackout due to a winter storm that cuts off power, communication and road networks. Due to hard winter weather it is essential to enhance the resilience of society to avoid danger to life. This can be achieved by developing new models to enhance preparedness for coming disaster events and to support rescue and other authorities to focus their resources on the most vulnerable targets in actual cases of emergencies. This paper presents a part of the results of activities performed within the… More >