2,438 research outputs found

    Pioneering Metallurgy: The origins of iron and steel making in the Southern Indian subcontinent Telangana Field Survey Interim Report 2011

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    A chapter from this report ("From the macroscopic to the microscopic: some scientific insights") is in ORE: http://hdl.handle.net/10871/17744British Council UKIER

    Ferromagnetically correlated clusters in semi-metallic Ru2NbAl Heusler alloy

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    In this work, we report the structural, magnetic and electrical and thermal transport properties of the Heusler-type alloy Ru2NbAl. From the detailed analysis of magnetization data, we infer the presence of superparamagnetically interacting clusters with a Pauli paramagnetic background, while short-range ferromagnetic interaction is developed among the clusters below 5 K. The presence of this ferromagnetic interaction is confirmed through heat capacity measurements. The relatively small value of electronic contribution to specific heat, gamma (~2.7 mJ/mol-K2), as well as the linear nature of temperature dependence of Seebeck coefficient indicate a semi-metallic ground state with a pseudo-gap that is also supported by our electronic structure calculations. The activated nature of resistivity is reflected in the observed negative temperature coefficient and has its origin in the charge carrier localization due to antisite defects, inferred from magnetic measurements as well as structural analysis. Although the absolute value of thermoelectric figure of merit is rather low (ZT = 5.2*10-3) in Ru2NbAl, it is the largest among all the reported non-doped full Heusler alloys.Comment: 25 pages, 14 figure

    Extensional viscosity of copper nanowire suspensions in an aqueous polymer solution

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    Suspensions of copper nanowires are emerging as new electronic inks for next-generation flexible electronics. Using a novel surface acoustic wave driven extensional flow technique we are able to perform currently lacking analysis of these suspensions and their complex buffer. We observe extensional viscosities from 3 mPa\cdots (1 mPa\cdots shear viscosity) to 37.2 Pa\cdots via changes in the suspension concentration, thus capturing low viscosities that have been historically very challenging to measure. These changes equate to an increase in the relative extensional viscosity of nearly 12,200 times at a volume fraction of just 0.027. We also find that interactions between the wires and the necessary polymer additive affect the rheology strongly. Polymer-induced elasticity shows a reduction as the buffer relaxation time falls from 819 to 59 μ\mus above a critical particle concentration. The results and technique presented here should aid in the future formulation of these promising nanowire suspensions and their efficient application as inks and coatings.Comment: 7 pages, 5 figures, under review for Soft Matter RS

    Study of drug utilization pattern in the department of radiotherapy in a tertiary care teaching hospital

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    Background: Drug utilization studies are an important tool in evaluating the rationality of therapeutic practice and also it is said to improvise the therapeutic use of drugs. The present study will be undertaken to evaluate the drug utilization pattern in the department of Radiotherapy.Methods: This was a prospective, observational study that was undertaken in the department of Radiotherapy in a tertiary care teaching hospital. The study was conducted for a period of 6 months after obtaining permission from Institutional Ethical Committee. The study was conducted among cancer patients undergoing radiotherapy. The data was collected from the patient case records and was analyzed as per the WHO prescribing indicators.Results: In the present study it was observed that the average number of drugs prescribed per encounter was 7.7. The drugs prescribed by generic name were 41.4%. Percentage of encounters with an antibiotic prescribed was 100. Percentage of encounters with an injection prescribed was 20.5%. Percentage of drugs prescribed from essential drugs list was 35.8%.Conclusions: Drug utilization studies helps in modifying the prescription pattern and helps in making the drug usage more rational

    Motility induced changes in viscosity of suspensions of swimming microbes in extensional flows

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    Suspensions of motile cells are model systems for understanding the unique mechanical properties of living materials which often consist of ensembles of self-propelled particles. We present here a quantitative comparison of theory against experiment for the rheology of such suspensions. The influence of motility on viscosities of cell suspensions is studied using a novel acoustically-driven microfluidic capillary-breakup extensional rheometer. Motility increases the extensional viscosity of suspensions of algal pullers, but decreases it in the case of bacterial or sperm pushers. A recent model [Saintillan, Phys. Rev. E, 2010, 81:56307] for dilute active suspensions is extended to obtain predictions for higher concentrations, after independently obtaining parameters such as swimming speeds and diffusivities. We show that details of body and flagellar shape can significantly determine macroscale rheological behaviour.Comment: 12 pages, 1 appendix, 7 figures, submitted to Soft Matter - under revie

    Post Prandial Hypertriglyceridemia as a Risk Factor for Macro Vascular Complications in Type 2 Diabetes Mellitus

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    The study “postprandial hypertriglyceridemia as a risk factor for macro vascular complications in type 2 diabetes mellitus” was a case control study conducted on patients visiting the out patient department of Government Rajaji Hospital, Madurai. Sixty eight patients with type 2 diabetes mellitus and 22 healthy controls were included in the study. Selected patients and controls underwent clinical and biochemical evaluation including blood sugar, lipid profile and cardiac function to detect the presence of macro vascular complications of diabetes. Selected patients and subjects were subjected to a high fat meal and plasma triglycerides were measured two and four hours after fat challenge. It was observed that post load hypertriglyceridemia correlated better than fasting triglycerides in patients with macro vascular complications. It was also observed that persistent postprandial hypertriglyceridemia was observed in diabetic patients with complications

    An Expert System Architecture to Detect System-Level Automotive EMC Problems

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    Improving EMC in automobiles requires methods to detect potential problems early in the design process. Issues involved in the development of a system-level automotive EMC expert system are explored. The proposed system would help identify problems with radiation and immunity, crosstalk, placement of modules, component grounding and EMC testing. The architecture of the expert system has been developed. The system architecture is designed to allow rapid analysis of automobile designs, to point out potential problems and to suggest possible solutions
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