Circular Capacitance Micromachined Ultrasonic Transducer

Capacitance micromachined ultrasonic transducers (CMUTs) have become an attractive alternative to the piezoelectric transducers, especially in air-coupled nondestructive evaluation (NDE) and ultrasound medical imaging flow metering,  micro/nanoelectronics, and industrial cleaning, etc. These are similar to other capacitance transducers as these employ a vibrating membrane to send and receive ultrasound in air and water. This paper describes the theory and design of a circular micromachined ultrasonic transducer which could lead to a CMUT with many advantages, including less loading effect. The software programs (Intellisuite 8.2 and MATLAB 7.0) were used to model a single cell of CMUT. The simulations-based studies of the critical parameters like collapse voltage and snapback voltage, which influence the operation of the CMUTs to a large extent, has been discussed. Small signal equivalent circuit model for the circular CMUT has been discussed and the program (SPICE) has been used for the simulation of the small signal equivalent circuit.Defence Science Journal, 2009, 59(6), pp.627-633, DOI:http://dx.doi.org/10.14429/dsj.59.156

Synthesis and biological evaluation of thiazolidinedione derivatives of chalcones and flavones as antihyperglycemic and antidyslipidemic agents

A series of chalcone and flavone derivatives (6a-d, 9a-f) based on 2,4-thiazolidinedione have been synthesized and evaluated for in vivo antihyperglycemic activity in sucrose loaded (SLM) and streptozotocin (STZ) induced diabetic animal models and also for antidyslipidemic activity in the triton model. Compounds 9d, 9e, and 9f exhibited potent blood glucose-lowering activity in both SLM and STZ models. Compounds 6c, 6d, and 9c, 9e, and 9f showed moderate lipid-lowering activity. The selected most potent compounds 6d and 9e were also studied in db/db mice for both antihyperglycemic and antidyslipidemic activity

Synthesis and biological evaluation of thiazolidinedione derivatives of chalcones and flavones as antihyperglycemic and antidyslipidemic agents

579-588A series of chalcone and flavone derivatives (6a-d, 9a-f) based on 2,4-thiazolidinedione have been synthesized and evaluated for in vivo antihyperglycemic activity in sucrose loaded (SLM) and streptozotocin (STZ) induced diabetic animal models and also for antidyslipidemic activity in the triton model. Compounds 9d, 9e, and 9f exhibited potent blood glucose-lowering activity in both SLM and STZ models. Compounds 6c, 6d, and 9c, 9e, and 9f showed moderate lipid-lowering activity. The selected most potent compounds 6d and 9e were also studied in db/db mice for both antihyperglycemic and antidyslipidemic activity

Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic

Development, Testing and Characterization of Al NanoTiCp Composites through Powder Metallurgy Techniques

In the present scenario, weight diminution and strength enrichment are the main requirements for escalating the application of a nano composite material in different sectors. Several industrial sectors, such as automobile, defense and aerospace, are making various components of nano composites with the help of powder metallurgy processing. In this study, Al nanoTiCp composites (2, 4 and 6 wt %) were contrived through modified powder metallurgy (PM) techniques with the help of Cold Isostatic Compaction process (CIP). The mechanical properties such as density, porosity, micro-hardness, compressive strength and indirect tensile strength were increasing with the reinforcement of nanoTiCp particles up to 4 wt % in Al metal matrix composites. Nevertheless, clustering of nanoTiCp particles were found at 6 wt %, which is also observed in SEM images

MrdH, a Novel Metal Resistance Determinant of Pseudomonas putida KT2440, Is Flanked by Metal-Inducible Mobile Genetic Elements▿ †

We report here the identification and characterization of mrdH, a novel chromosomal metal resistance determinant, located in the genomic island 55 of Pseudomonas putida KT2440. It encodes for MrdH, a predicted protein of ∼40 kDa with a chimeric domain organization derived from the RcnA and RND (for resistance-nodulation-cell division) metal efflux proteins. The metal resistance function of mrdH was identified by the ability to confer nickel resistance upon its complementation into rcnA mutant (a nickel- and cobalt-sensitive mutant) of Escherichia coli. However, the disruption of mrdH in P. putida resulted in an increased sensitivity to cadmium and zinc apart from nickel. Expression studies using quantitative reverse transcription-PCR showed the induction of mrdH by cadmium, nickel, zinc, and cobalt. In association with mrdH, we also identified a conserved hypothetical gene mreA whose encoded protein showed significant homology to NreA and NreA-like proteins. Expression of the mreA gene in rcnA mutant of E. coli enhanced its cadmium and nickel resistance. Transcriptional studies showed that both mrdH and mreA underwent parallel changes in gene expression. The mobile genetic elements Tn4652 and IS1246, flanking mrdH and mreA were found to be induced by cadmium, nickel, and zinc, but not by cobalt. This study is the first report of a single-component metal efflux transporter, mrdH, showing chimeric domain organization, a broad substrate spectrum, and a location amid metal-inducible mobile genetic elements