Indian Institute of Technology Kharagpur

About: Indian Institute of Technology Kharagpur is a education organization based out in Kharagpur, India. It is known for research contribution in the topics: Natural rubber & Dielectric. The organization has 16887 authors who have published 38658 publications receiving 714526 citations.

Sequenceserver: a modern graphical user interface for custom BLAST databases

Abstract: The dramatic drop in DNA sequencing costs has created many opportunities for novel biological research. These opportunities largely rest upon the ability to effectively compare newly obtained and previously known sequences. This is commonly done with BLAST, yet using BLAST directly on new datasets requires substantial technical skills or helpful colleagues. Furthermore, graphical interfaces for BLAST are challenging to install and largely mimic underlying computational processes rather than work patterns of researchers. We combined a user-centric design philosophy with sustainable software development approaches to create Sequenceserver (http://sequenceserver.com), a modern graphical user interface for BLAST. Sequenceserver substantially increases the efficiency of researchers working with sequence data. This is due first to innovations at three levels. First, our software can be installed and used on custom datasets extremely rapidly for personal and shared applications. Second, based on analysis of user input and simple algorithms, Sequenceserver reduces the amount of decisions the user must make, provides interactive visual feedback, and prevents common potential errors that would otherwise cause erroneous results. Finally, Sequenceserver provides multiple highly visual and text-based output options that mirror the requirements and work patterns of researchers. Together, these features greatly facilitate BLAST analysis and interpretation and thus substantially enhance researcher productivity.

Complex impedance studies of sodium pyrotungstate – Na2W2O7

Abstract: Polycrystalline Na2W2O7 (anhydrous) was prepared by a solid-state reaction technique. The formation of the compound has been confirmed by X-ray powder diffraction studies and Raman spectroscopy. The unit cell structure of the material has been found to be orthorhombic of the Cmca space group. Complex impedance analysis of the material indicates the electrical conduction to be due only to the grain interior up to a temperature of 300 °C. Above 300 °C the contribution of the grain boundary to electrical conduction is more evident. The grain boundary resistance is found to decrease with increasing temperature. Impedance results also indicate that the material exhibits a negative temperature coefficient of resistance. The electrical processes in the material show temperature-dependent relaxation phenomena. The electrical conduction in the material is a thermally activated process governed by the release of space charge in close agreement with the observations made from impedance spectrum analysis. The dc conductivity of the material as evaluated from the complex impedance spectrum is observed to attain a maximum value of 1.16 × 10−6 S cm−1 at 425 °C. This is a very large increase, nearly four orders of magnitude, when compared with the room temperature conductivity of the material (3.99 × 10−10 S cm−1). (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)