Jatropha curcas: Plant of Medical Benefits

Plants are a rich source of many natural products most of which have been extensively used for human welfare, and treatment of various diseases. Jatropha curcas, a multipurpose, drought resistant, perennial plant belonging to Euphorbiaceae family is gaining a lot of economic importance because of its several potentials in industrial application and medicinal values. J. curcas has been used as traditional medicine to cure various infections. Researchers had isolated and characterized numerous biologically active compounds from all parts of this plant. In addition, the mechanisms of action of these active compounds have been studied in relation to the applications in traditional medicine. Before exploiting any plant for medicinal application, it is crucial to have complete information about the medicinal uses of each part of the plant. The medicinal uses of the leaves, fruit, seed, stem bark, branches, twigs, latex and root of J. curcas are discussed in this review. If the full potential of the plant is to be revealed, much more research is required to develop herbal medicine using modern science and technology. A potential aspect based on markets for all of its medicinal products should be conducted thoroughly, to promote the ability of this plant to cure so many illnesses

Effects of Electrode Materials on Power Generation of Microbial Fuel Cell

Energy shortage and environmental pollution mainly caused the global energy crisis which led to serious impact on human survival and development. Microbial fuel cells (MFCs) exactly meet the requirements to alleviate the global energy crisis because it has the ability to treat the wastewater and produce electricity concurrently. MFCs are considered as one of the promising technology in the wastewater treatment technology. The power output depends on various factors such as substrate degradation, electrode material, rate of electron transfer from bacteria to the anode, circuit resistance, proton mass transfer in the liquid, external operating conditions and so on. Electrode material is one of the key factors which affect the performance of MFC. Therefore, it is of great significance to select and develop suitable electrode materials to optimize and promote the performance of MFCs. Each electrode material has its own physical and chemical properties such as surface area, electric conductivity and chemical stability. In this research, we have tested two different electrode materials such as; polyacrlyonitrile carbon felt (PACF) and single forward carbon cloth (SFCC) to study the effects of different electrode materials on MFC performance. The results showed that MFC with SFCC using raw POME showed high power density (102.5mW/m2) compared to PACF (45mW/m2). But COD removal efficiency with raw POME of SFCC (43%) and PACF (45%) were not shown much difference. The coulombic efficiency of 1:50 diluted POME reached upto 26% for SFCC whereas for PACF 24% was achieved. SFCC achieved the highest coulombic efficiency and power output than PACF, indicating SFCC facilitate the biofilm formation and improve power generation

Oxidation mechanism in metal nanoclusters: Zn nanoclusters to ZnO hollow nanoclusters

Zn nanoclusters (NCs) are deposited by Low-energy cluster beam deposition technique. The mechanism of oxidation is studied by analysing their compositional and morphological evolution over a long span of time (three years) due to exposure to ambient atmosphere. It is concluded that the mechanism proceeds in two steps. In the first step, the shell of ZnO forms over Zn NCs rapidly up to certain limiting thickness: with in few days -- depending upon the size -- Zn NCs are converted to Zn-ZnO (core-shell), Zn-void-ZnO, or hollow ZnO type NCs. Bigger than ~15 nm become Zn-ZnO (core-shell) type: among them, NCs above ~25 nm could able to retain their initial geometrical shapes (namely triangular, hexagonal, rectangular and rhombohedral), but ~25 to 15 nm size NCs become irregular or distorted geometrical shapes. NCs between ~15 to 5 nm become Zn-void-ZnO type, and smaller than ~5 nm become ZnO hollow sphere type i.e. ZnO hollow NCs. In the second step, all Zn-void-ZnO and Zn-ZnO (core-shell) structures are converted to hollow ZnO NCs in a slow and gradual process, and the mechanism of conversion proceeds through expansion in size by incorporating ZnO monomers inside the shell. The observed oxidation behaviour of NCs is compared with theory of Cabrera - Mott on low-temperature oxidation of metal.Comment: 9 pages, 8 figure

Effect of hydrogen on ground state structures of small silicon clusters

We present results for ground state structures of small Si$_{n}$H (2 \leq \emph{n} \leq 10) clusters using the Car-Parrinello molecular dynamics. In particular, we focus on how the addition of a hydrogen atom affects the ground state geometry, total energy and the first excited electronic level gap of an Si$_{n}$ cluster. We discuss the nature of bonding of hydrogen in these clusters. We find that hydrogen bonds with two silicon atoms only in Si$_{2}$H, Si$_{3}$H and Si$_{5}$H clusters, while in other clusters (i.e. Si$_{4}$H, Si$_{6}$H, Si$_{7}$H, Si$_{8}$H, Si$_{9}$H and Si$_{10}$H) hydrogen is bonded to only one silicon atom. Also in the case of a compact and closed silicon cluster hydrogen bonds to the cluster from outside. We find that the first excited electronic level gap of Si$_{n}$ and Si$_{n}$H fluctuates as a function of size and this may provide a first principles basis for the short-range potential fluctuations in hydrogenated amorphous silicon. Our results show that the addition of a single hydrogen can cause large changes in the electronic structure of a silicon cluster, though the geometry is not much affected. Our calculation of the lowest energy fragmentation products of Si$_{n}$H clusters shows that hydrogen is easily removed from Si$_{n}$H clusters.Comment: one latex file named script.tex including table and figure caption. Six postscript figure files. figure_1a.ps and figure_1b.ps are files representing Fig. 1 in the main tex

Exact Schwarzschild-Like Solution for Yang-Mills Theories

Drawing on the parallel between general relativity and Yang-Mills theory we obtain an exact Schwarzschild-like solution for SU(2) gauge fields coupled to a massless scalar field. Pushing the analogy further we speculate that this classical solution to the Yang-Mills equations shows confinement in the same way that particles become confined once they pass the event horizon of the Schwarzschild solution. Two special cases of the solution are considered.Comment: 11 pages LaTe

An Electro-Optical Technique For The Measurement Of Temperature Of High Potential Bodies.

In this paper we have presented a low cost, simple and robust mechatronic system for the measurement of temperature in extreme conditions. It is specially designed for the protection of high potential parts of power transformers and switch gears under faulty operating conditions

Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere

Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector; morning and dayside auroras; auroral plasma formation; electrodynamic coupling with the thermosphere; and auroral electron interaction with the atmosphere