Mustapha FARAJI¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.1, pp. 19-36, 2017, DOI:10.3970/fdmp.2017.013.019

Abstract A two-dimensional numerical model that accounts for heat transfer by conduction and natural convection in the molten region of nano enhanced Phase Change Material (PCM) is performed. Numerical investigations were conducted using an enthalpy- porosity method in order to examine the impact of the dispersion of copper (CuO) nanoparticles on the heat source temperature and the effect on the heat sink secured working time and the melting rate. Results show that heat spreads more easily along the conducting plate and to the PCM and, consequently, the PCM melts rapidly and the heat source is efficiency More >

Qin YY^1,2, F Qi¹, NM Holden³, JJ Cao⁴

Phyton-International Journal of Experimental Botany, Vol.85, pp. 149-154, 2016, DOI:10.32604/phyton.2016.85.149

Abstract The Heihe River Basin is a globally significant carbon pool, but its soil organic carbon dynamics is poorly understood. Soil samples taken between 2500 m and 4100 m revealed that the majority (>75%) of soil organic carbon was from 0-40 cm. It showed a negative relationship with pH and soil bulk density, and a positive relationship with altitude and soil water content, respectively. From 2005 to 2011, soil carbon content in the upper catchment decreased from 93 g/kg to 53 g/kg. These results suggest that policies should aim to reduce carbon loss by transferring it More >

Alvarado-Vázquez MA, R Foroughbakhch, MA Guzmán- Lucio, A Rocha-Estrada, JL Hernández-Piñero, ML Cárdenas-Ávila, BM Soto-García

Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 70-79, 2015, DOI:10.32604/phyton.2015.84.070

Abstract Candelilla (Euphorbia antisiphylitica Zucc.) is a very important plant resource in the arid lands of Northern Mexico. This is because the wax content coating the stem has unique properties which have been useful for multiple applications in the food industry, electronics, cosmetics, etc. However, the intensive exploitation of this resource has caused a great decrease in the populations of this species making necessary to consider strategies for their conservation and sustainable use. One of the primary needs with regeneration purposes is to know their reproductive processes, particularly the biotic and/or abiotic factors that determine the viability… More >

Ravishankar Sathyamurthy^a,*, P.K. Nagarajan^b, Hyacinth J. Kennady^a, T.S. Ravikumar^a, V. Paulson^c, Amimul Ahsan^d

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-5, 2014, DOI:10.5098/hmt.5.3

Abstract This paper presents the method of improvement of enhancing the performance of triangular pyramid solar still with and without latent heat energy storage. For comparing the productivity of solar still with and without LHTESS a solar still is designed, fabricated. Experiments are conducted in hot and humid climate of Chennai, India. Paraffin wax is used as LHTESS due to its feasible general and economic properties. The hourly productivity is slightly higher in case of solar still without LHTESS during sunny days. There is an increase of about 35% in production of fresh water with LHTESS More >

Mustapha Faraji¹, El Alami Mustapha, Najam Mostafa

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 279-298, 2014, DOI:10.3970/fdmp.2014.010.279

Abstract A study is reported of heat transfer and melting in a fan-less thermal management system consisting of an insulated horizontal cavity filled with a phase change material (PCM) and heated from below by a conducting plate supporting three identical protruding heat sources. Such a PCM enclosure can be used as a heat sink for the cooling of electronic components. The advantage of this cooling strategy is that PCMs characterized by high energy storage density and small transition temperature interval, are able to store a high amount of heat (thereby providing efficient passive cooling). A two-dimensional More >

K. Lahmer¹, R. Bessaïh¹, A. Scipioni², M. El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 149-162, 2014, DOI:10.3970/fdmp.2014.010.149

Abstract This paper summarizes the outcomes of a numerical study about the phenomenon of hydrogen absorption in an axisymmetric tank geometry containing magnesium hydride heated to 300˚C and at moderate storage pressure 1 MPa. The governing equations are solved with a fully implicit finite volume numerical scheme (as implemented in the commercial software FLUENT). Different kinetic reaction equations modeling hydrogen absorption are considered and the related numerical simulations are compared with experimental results. Spatial and temporal profiles of temperature and concentration in hydride bed are plotted. More >

A. Valan Arasu^a,*, Agus P. Sasmito^b,†, Arun S. Mujumdar^b

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3005

Abstract The heat transfer enhancement of paraffin wax, a cheap and widely used latent heat thermal energy storage material, using nanoparticles is investigated. The effects of nanoparticle volume fraction on both the melting and solidification rates of paraffin wax are analysed and compared for Al₂O₃ and CuO nanoparticles. Present results show that dispersing nanoparticles in smaller volumetric fractions increase the heat transfer rate. The enhancement in thermal performance of paraffin wax is greater for Al₂O₃ compared with that for CuO nanoparticles. More >

Jurado E¹, M Márquez-Linares², J Flores³

Phyton-International Journal of Experimental Botany, Vol.80, pp. 101-105, 2011, DOI:10.32604/phyton.2011.80.101

Abstract We evaluated the effect of cold storage and fire-related cues on seed germination of Arctostaphylos pungens HBK (Mexican Manzanita), a common shrub in poorly managed pine-oak forests in Durango, Mexico. Because this shrub has a high density in previously burnt forests, we investigated the effect that high temperatures, smoke and charcoal might have on seed germination of this species. Seeds were collected fresh from the shrubs. The highest germination was 30% for seeds that had been cold stored, heat shocked, past through smoke and watered with diluted charcoal. More >

Ralph H. Scheicher

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 93-94, 2011, DOI:10.3970/icces.2011.019.093

Abstract The purpose of this talk is to provide an overview of the most recent theoretical studies undertaken by us in the field of hydrogen storage materials research. On selected examples, the application of our computational tool of choice, density functional theory, will be illustrated to show how ab initio calculations can be of use in the effort to reach a better understanding of hydrogen storage materials and to occasionally also guide the search for new promising approaches. Systems to be discussed include: Metal-organic frameworks, where we have studied hydrogen physisorption in three different types of… More >

Gotthard Seifert, Aliezer Martinez Mesa, Sergei Yurchenko, Bassem Assfour¹, Thomas Heine³, Sergei Patchkovsk

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 21-22, 2011, DOI:10.3970/icces.2011.018.021

Abstract In this study structural characteristics of several carbon based nanostructures and organic frameworks as metal organic frameworks (MOF) and covalent organic frameworks (COF) on the hydrogen abundance in the material are investigated with the quantized liquid density functional theory (QLDFT), Molecular Dynamics (MD) and Grand Canonical Monte Carlo (GCMC). We applied these theories to evaluate the hydrogen storage capacities of nanoporous materials: Compact storage of hydrogen is the key challenge facing adoption of hydrogen as fuel for mobile applications. A promising approach to increase the storage densities is the adsorption of molecular hydrogen in porous More >