Simple rules for the understanding of Heusler compounds

Mobility (transport of people and goods) is a socio-economic reality and need for which is bound to grow in the coming years. Modes of transport should be safe, economic and reasonably environmental friendly. Hydrogen could be ideal as a synthetic energy carrier for transport sector as its gravimetric energy density is very high, abundantly available in combined form on the earth and its oxidation product (water) does not contribute to greenhouse gas emissions. However, its sustainable production from renewable resources economically, on-board storage to provide desirable driving range, usage in durable energy conversion devices and development of infrastructure for its delivery remain significant challenges. In this article, recent developments in the field of production, storage, transport and delivery of hydrogen along with environmental and safety aspects of its use as an energy carrier are presented. Almost any energy source can be used to produce hydrogen. Presently, non-renewable sources dominate hydrogen production processes but the need of the hour is to develop and promote the share of renewable sources for hydrogen production to make it completely sustainable. Hydrogen may be used as fuel for almost any application, where fossil fuels are used presently and would offer immediate benefits over the conventional fuels, if produced from renewable sources. For achieving a successful "hydrogen economy" in the near future, the technical and economic challenges associated with hydrogen must be addressed quickly. Finding feasible solutions to different challenges may take some time but technological breakthrough by way of on-going efforts do promise hydrogen as the ultimate solution for meeting our future energy needs for the transport sector.

Hydrogen: A sustainable fuel for future of the transport sector

Balsamodendron mukul (Guggul): The Oleo-gum-resin exuded by this tree has been regarded as a sovereign remedy in ancient medicine. It is a bitter stomachic and carminative and improves digestion. It is quickly absorbed and is excreted by skin, mucous membranes and kidneys and in the course of excretion it disinfects their secretions improves the function and stimulates the activity of the respective organs. It has marked antiseptic properties.

Composition 构好图，出好片

The support plays an important role for supported metal catalysts by positioning itself as a macromolecular ligand, which conditions the nature of the active site and contributes indirectly but also sometimes directly to the reactivity. Metal species such as nanoparticles, clusters, or single atoms can be deposited on carbon materials for various catalytic reactions. All the carbon materials used as catalyst support constitute a large family of compounds that can vary both at textural and at structural levels. Today, the recent developments of well-controlled synthesis methodologies, advanced characterization techniques, and modeling tools allow one to correlate the relationships between metal/support/reactant at the molecular level. Based on these considerations, in this Review article, we wish to provide some answers to the question "How and why anchoring metal nanoparticles, clusters, or single atoms on carbon materials for catalysis?". To do this, we will rely on both experimental and theoretical studies. We will first analyze what sites are available on the surface of a carbon support for the anchoring of the active phase. Then, we will describe some important effects in catalysis inherent to the presence of a carbon-type support (metal-support interaction, confinement, spillover, and surface functional group effects). These effects will be commented on by putting into perspective catalytic results obtained in numerous reactions of thermal catalysis, electrocatalysis, or photocatalysis.

A Theory/Experience Description of Support Effects in Carbon-Supported Catalysts.

A review on the magnetorheological fluid preparation and stabilization

Cerium oxide (CeO2) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium oxide nanoparticles. The Scanning Electron Microscopy (SEM) analysis showed that the nanoparticles agglomerated forming spherical-shaped particles. The Transmission Electron Microscopic (TEM) analysis confirmed the prepared cerium oxide nanoparticles with the particle size being found to be 16 nm. The optical absorption spectrum showed a blue shift by the cerium oxide nanoparticles due to the quantum confinement effect. The dielectric properties of cerium oxide nanoparticles were studied for different frequencies at different temperatures. The dielectric constant and the dielectric loss of the cerium oxide nanoparticles decreased with increase in frequency. The AC electrical conductivity study revealed that the conduction depended on both the frequency and the temperature.

https://www.scielo.br/pdf/mr/v19n2/1516-1439-mr-1980-5373-MR-2015-0698.pdf

Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles

Li-decorated double vacancy graphene for hydrogen storage application: A first principles study

Cobalt oxide (Co3O4) nanoparticles were synthesized using precipitation method. The X-ray diffraction (XRD) pattern was used to determine the structure of Co3O4 nanoparticles. The presence of Co3O4 nanoparticles was confirmed by the FTIR spectrum. The fact about the surface morphology of Co3O4 nanoparticles was revealed by scanning electron microscopic analysis. Transmission electron microscopy was used to measure the particle size of the Co3O4 nanoparticles. The absorption spectrum made it possible to analyze the optical properties of Co3O4 nanoparticles. This work contributes to the study of dielectric properties such as the dielectric loss and the dielectric constant of Co3O4 nanoparticles, at varied frequencies and temperatures. The magnetic properties of the Co3O4 nanoparticles were also investigated.

Precipitation method and characterization of cobalt oxide nanoparticles

The main aim of this article is to prepare MR fluids, composed of iron particles and analyse their flow behaviour in terms of the internal structure, stability and magneto rheological properties. MR fluids are prepared using silicone oil (OKs) mixed with iron powder. To reduce sedimentation, grease is added as stabilizers. The size of the particles is observed by Optical microscope and flow properties are examined by rheometer. Sedimentation is measured by simple observation of changes in boundary position between clear and turbid part of MR fluid placed into glass tube. The various additive percentages can also influence the MR fluid’s performances.

/pdf/magneto-mechanical-properties-of-iron-based-mr-fluids-205d2mhcg8.pdf

Manickam Mahendran

Papers

Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles

Li-decorated double vacancy graphene for hydrogen storage application: A first principles study

Precipitation method and characterization of cobalt oxide nanoparticles

Magneto Mechanical Properties of Iron Based MR Fluids

Al-decorated carbon nanotube as the molecular hydrogen storage medium