Thermoelectric efficiency of topological insulators in a magnetic field

We study the thermoelectric properties of three-dimensional topological insulators in magnetic fields with many holes (or pores) in the bulk. We find that at high density of these holes in the transport direction the thermoelectric figure of merit, ZT, can be large due to the contribution of the topologically protected conducting surfaces and the suppressed phonon thermal conductivity. By applying an external magnetic field a subgap can be induced in the surface states spectrum. We show that the thermoelectric efficiency can be controlled by this tunable subgap leading to the values of ZT much greater than 1. Such high values of ZT for reasonable system parameters and its tunability by magnetic field make this system a strong candidate for applications in heat management of nanodevices, especially at low temperatures.Comment: 9 pages, 4 figures, Proceedings of MMM 201

The feeding behaviour and Plasmodium infection of Anopheles mosquitoes in southern Ethiopia in relation to use of insecticide-treated livestock for malaria control.

Anopheles arabiensis and An. quadriannulatus species B mosquitoes were collected at sites of human and livestock housing and analysed for blood feeding patterns and infection with malaria sporozoites. A low percentage of human blood meals at some sites suggested that zooprophylaxis could be effective in reducing challenge from Plasmodium falciparum

Characterization of bulk MgB2 synthesized by infiltration and growth

Superconducting MgB2 has been synthesized successfully by a modified infiltration and growth (IG) technique. The ambient pressure technique is relatively simple and scalable to complex shaped bulks. The extent of MgB 2 phase formation has been found to be influenced strongly by the IG process time and/or temperature, and this is found to reflect in the X-ray diffraction patterns, magnetization measurements, and microhardness. Scanning electron microscopy images show a bimodal particle size distribution with 20-50 nm sized fine precipitates in the inter particle region. A critical current density of 400 kA cm-2 was measured at 5 K.KACST-Cambridge Research Centre, Cambridge, U.K

Urgensi Pendidikan Non Formal Terhadap Pendidikan Leadership

Bangsa yang mampu menemukan cara untuk mengamalkan moralnya, berdasarkan etos yang bangsa tersebut miliki sendiri dan tetap dengan berbagi dan saling mengisi, dan berhubungan dengan bangsa lain, diyakini akan mampu bertahan didalam dunia yang semakin kompleks. Untuk mejadikan bangsa seperti itu diperlukan masyarakat yang paham akan makna kepemimpinan. Sehingga diperlukan sebuah sistem pendidikan kepemimpinan. Semua lembaga nonformal mempunyai kesempatan yang sama untuk menciptakan sistem dan melakukannya secara terorganisasi. Tulisan berikut akan berupaya memberikan paparan tentang peran setrategis lembaga-lembaga nonformal dalam melakukan proses pendidikan kepemimpinan. Pendidikan dan latihan kepemimpinan di lembaga pendidikan nonformal bisa di lakukan dengan dua model, yaitu : model integrasi (integration model) dan model terpisah. Materi pendidikan kepemimpinan dapat dikategorikan dalam beberapa pokok materi yaitu : idiologi, kenegaraan dan kebangsaan; prilaku organisasi; komunikasi massa; pemecahan masalah dan pengambilan keputusan; manajemen konflik dan motivasi berprestasi

On the role of magnetic reconnection in jet/accretion disk systems

The most accepted model for jet production is based on the magneto-centrifugal acceleration out off an accretion disk that surrounds the central source (Blandford & Payne, 1982). This scenario, however, does not explain, e.g., the quasi-periodic ejection phenomena often observed in different astrophysical jet classes. de Gouveia Dal Pino & Lazarian (2005) (hereafter GDPL) have proposed that the large scale superluminal ejections observed in microquasars during radio flare events could be produced by violent magnetic reconnection (MR) episodes. Here, we extend this model to other accretion disk systems, namely: active galactic nuclei (AGNs) and young stellar objects (YSOs), and also discuss its role on jet heating and particle acceleration.Comment: To be published in the IAU Highlights of Astronomy, Volume 15, XXVII IAU General Assembly, August 2009, Ian F. Corbett et al., eds., 201

Dynamic modelling and applications for passenger car powertrains

Torsional finite elements for direct, geared, branched and grounded connections are presented. For a simple three-degrees-of-freedom powertrain model the finite elements are defined and the global system assembly is detailed. The appropriateness of the finite element method for powertrain systems is illustrated via examples for modelling manual, automatic and continuously variable transmissions. The use of custom elements is discussed for an element for toroid-roller contact and for a two-stage planetary gear set. A test rig is presented and model verification is discussed

Evaluating tools to support a new practical classification of diabetes: excellent control may represent misdiagnosis and omission from disease registers is associated with worse control.

To conduct a service evaluation of usability and utility on-line clinical audit tools developed as part of a UK Classification of Diabetes project to improve the categorisation and ultimately management of diabetes

FLAGCAL:A flagging and calibration package for radio interferometric data

We describe a flagging and calibration pipeline intended for making quick look images from GMRT data. The package identifies and flags corrupted visibilities, computes calibration solutions and interpolates these onto the target source. These flagged calibrated visibilities can be directly imaged using any standard imaging package. The pipeline is written in "C" with the most compute intensive algorithms being parallelized using OpenMP.Comment: 15 Pages, 6 figures, 2 Tables, Accepted for publication in the Experimental Astronomy Journa