Ranjan K. Singh

Bio: Ranjan K. Singh is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Raman spectroscopy & Liquid crystal. The author has an hindex of 20, co-authored 134 publications receiving 1465 citations. Previous affiliations of Ranjan K. Singh include Schiller International University & University of Würzburg.

Syntheses, spectral, X-ray and DFT studies of 5-benzyl-N-phenyl-1,3,4 -thiadiazol-2-amine, 2-(5-phenyl-1,3,4-thiadiazol-2-yl) pyridine and 2

Abstract: New compounds 5-benzyl-N-phenyl-1,3,4-thiadiazol-2-amine (Bptha, 1), 2-(5-phenyl-1,3,4-thiadiazol2-yl) pyridine (Pthp, 2) and 2-(5-methyl-1,3,4-thiadiazole-2-ylthio)-5-methyl-1,3,4-thiadiazole (Mtmth, 3) have been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray data. The structure of compounds 1, 2 and 3 are stabilized via intramolecular as well as intermolecular hydrogen bonding and crystallize in monoclinic system with space group P 1, P21/n and P 1, respectively. During the course of reaction, the substituted thiosemicarbazide/thiohydrazide get cyclized into the corresponding thiadiazole in the presence of manganese(II) nitrate via loss of H2O to yield compounds 1 and 2. However condensation occurred in the case of 5-methyl-1,3,4-thiadiazole-2-thiol which yielded 2-(5-methyl-1,3,4-thiadiazole-2-ylthio)-5-methyl-1,3,4-thiadiazole (3) by loss of one mole of H2S from two moles of 5-methyl-1,3,4-thiadiazole-2-thiol in the presence of manganese(II) acetate. The geometry optimization has been performed using DFT method and geometrical parameters thus obtained for the compounds have been compared with their single crystal X-ray data. The negative values of HOMO and LUMO energies for the molecules indicate that they are stable. The electronic transition from the ground state to the excited state due to a transfer of electrons from the HOMO to LUMO levels is mainly associated with the p ��� p transition.

Genetic Engineering: Altering the Threads of Life

Abstract: Over the past 30 years, the field of genetic engineering has grown in a spectacular manner. The methods involved in genetic engineering which were earlier considered cumbersome and involved sophisticated instrumentation have now became a common drill within the laboratories throughout the world. This rising technology is now involved in almost every aspect of biological research. Its application includes medical diagnosis, paternity disputes, forensic analysis, genome sequencing, etc. In the recent years, this technology has attained a large-scale attention, and now the commercial products developed using genetic engineering are known worldwide. The technique of genetic engineering is solely based on genetic information, which is encoded by the DNA in the form of genes. Through genetic engineering the genes can be introduced or manipulated within the host to develop products of value and importance, for treatment of genetic disorders, and to achieve other goals. The present chapter explains the techniques involved in genetic engineering and rDNA technology and its importance in revolutionizing different fields. The objective of this chapter is to highlight the basic principle and methodology involved in genetic engineering and its role in human welfare.

An overview of the phytosynthesis of various metal nanoparticles.

Abstract: Nanotechnology is an emerging branch of science wherein various valuable molecules with altered properties can be synthesized and utilized for numerous technological applications. Nowadays, nanotechnology is the preferred tool for the agriculture, food, and medicine industries. However, consistent accumulation of toxic by-products during the synthesis of nanoparticles from the established physical and chemical methods imposes an unprecedented danger to the environment and human well-being. The biological route for the synthesis of nanoparticles offers a potential option over the conventional chemical synthesis process due to the involvement of non-toxic and environmentally friendly materials, such as plants, fungi, bacteria, etc. Phytosynthesis, a type of biological synthesis, utilizes various combinations of secondary metabolites from different plant parts (whole plant, leaves, fruit peel, root, bark, seeds, and stem) for non-toxic and environmentally friendly nanoparticles fabrication. Non-toxic and environmentally friendly secondary metabolites derived from plants are the sources of reducing and capping agents during the biosynthesis of nanoparticles which proceeds in a controlled manner with desired characteristics. Phytosynthesis of nanoparticles is also a simple, economic, durable, and reproducible process. The present article is a comprehensive depiction of the synthesis of different metal nanoparticles from diverse plant species.

Surface-enhanced Raman spectroscopy (SERS): progress and trends

Abstract: Surface-enhanced Raman spectroscopy (SERS) combines molecular fingerprint specificity with potential single-molecule sensitivity. Therefore, the SERS technique is an attractive tool for sensing molecules in trace amounts within the field of chemical and biochemical analytics. Since SERS is an ongoing topic, which can be illustrated by the increased annual number of publications within the last few years, this review reflects the progress and trends in SERS research in approximately the last three years. The main reason why the SERS technique has not been established as a routine analytic technique, despite its high specificity and sensitivity, is due to the low reproducibility of the SERS signal. Thus, this review is dominated by the discussion of the various concepts for generating powerful, reproducible, SERS-active surfaces. Furthermore, the limit of sensitivity in SERS is introduced in the context of single-molecule spectroscopy and the calculation of the 'real' enhancement factor. In order to shed more light onto the underlying molecular processes of SERS, the theoretical description of SERS spectra is also a growing research field and will be summarized here. In addition, the recording of SERS spectra is affected by a number of parameters, such as laser power, integration time, and analyte concentration. To benefit from synergies, SERS is combined with other methods, such as scanning probe microscopy and microfluidics, which illustrates the broad applications of this powerful technique.

Solar-driven reforming of lignocellulose to H 2 with a CdS/CdO x photocatalyst

Abstract: This work was supported by the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development), the OMV Group (to E.R.), the EPSRC (DTA studentships for D.W.W. and T.E.R), the Isaac Newton Trust, the German Research Foundation (to M.F.K.), the World Premier Institute Research Center Initiative (WPI), MEXT, Japan (to K.L.O.) and a Marie Curie Research fellowship (to K.H.L., GAN 701192 - VSHER).

Organic Photoreceptors for Imaging Systems

Abstract: Xerographic photoreceptors charge acceptance and dark discharge photoinduced discharge photogeneration theories photogeneration in organic solids charge transport theories charge transport in polymers and related materials experimental techniques photoreceptor preparation photoreceptors fatigue summary and future requirements.

Assessing Genetic Risks: Implications for Health and Social Policy

Abstract: Ed Lori B Andrews, Jane E Fullarton, Neil A Holtzman, Arno G Motulsky National Academy Press, £28.95, pp 338 ISBN 0-309-04798-6 Genetic screening tends to serve as a flypaper on which our hovering fears of a Brave New World alight and stick. In the future of all-conquering genetic technology, who should be screened for what and by whom? Here is a dense report, compiled by a committee of the great and the good, with hundreds of recommendations for action and inaction. How much …