Low-inductance axial flux BLDC motor drive for more electric aircraft

As aircraft technology is moving towards more electric architecture, use of electric motors in aircraft is increasing. Axial flux BLDC motors (brushless DC motors) are becoming popular in aero application because of their ability to meet the demand of light weight, high power density, high efficiency and high reliability. Axial flux BLDC motors, in general, and ironless axial flux BLDC motors, in particular, come with very low inductance Owing to this, they need special care to limit the magnitude of ripple current in motor winding. In most of the new more electric aircraft applications, BLDC motor needs to be driven from 300 or 600 Vdc bus. In such cases, particularly for operation from 600 Vdc bus, insulated-gate bipolar transistor (IGBT)-based inverters are used for BLDC motor drive. IGBT-based inverters have limitation on increasing the switching frequency, and hence they are not very suitable for driving BLDC motors with low winding inductance. In this study, a three-level neutral point clamped (NPC) inverter is proposed to drive axial flux BLDC motors. Operation of a BLDC motor driven from three-level NPC inverter is explained and experimental results are presented.

Toward More Precise Radiotherapy Treatment of Lung Tumors

A computational framework for modeling the respiratory motion of lung tumors provides a 4D parametric representation that tracks, analyzes, and models movement to provide more accurate guidance in the planning and delivery of lung tumor radiotherapy.

A little more gauge mediation and the light Higgs mass

We consider minimal models of gauge mediated supersymmetry breaking with an extra U(1) factor in addition to the Standard Model gauge group. A U(1) charged, Standard Model singlet is assumed to be present which allows for an additional NMSSM like coupling, lambda HuHdS. The U(1) is assumed to be flavour universal. Anomaly cancellation in the MSSM sector requires additional coloured degrees of freedom. The S field can get a large vacuum expectation value along with consistent electroweak symmetry breaking. It is shown that the lightest CP even Higgs boson can attain mass of the order of 125 GeV. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).

Foliar Extrafloral Nectar of Humboldtia brunonis (Fabaceae), a Paleotropic Ant-plant, is Richer than Phloem Sap and More Attractive than Honeydew

The ant-plant Humboldtia brunonis secretes extrafloral nectar (EFN) despite the lack of antiherbivore protection from most ants. EFN was richer in composition than phloem sap and honeydew from untended Hemiptera on the plant, suggesting that EFN could potentially distract ants from honeydew, since ants rarely tended Hemiptera on this plant.

A taxonomic mystery for more than 180 years: the identity and systematic position of Brachysaura minor (HARDWICKE & GRAY, 1827)

Brachysaura is a monotypic genus of agamid lizard found in the Indian subcontinent; the identity and systematic position of B. minor has been long debated, and it has at times been subsumed into Agama, Charasia and Laudakia, with some authors suggesting affinities to Calotes. We constructed nuclear and mitochondrial phylogenetic trees including Brachysaura and allied agamid genera to resolve its phylogenetic position. We also compared osteology and external morphology with the genera Agama, Calotes and Laudakia. Hemipenial morphology was compared with Calotes and some other agamids from South Asia. Both nuclear and mitochondrial phylogenies demonstrate that Brachysaura is nested within the widespread South and Southeast Asian genus Calotes, with which it also shares certain external morphological, osteological and hemipenial characters. Adaptations to ground dwelling in Brachysaura minor has resulted in unique modifications to its body plan, which is likely why generic allocation has been long confused. This study also highlights the need for an integrated systematic approach to resolve taxonomic ambiguity in Asian agamids.

No More HF: Teflon-Assisted Ultrafast Removal of Silica to Generate High-Surface-Area Mesostructured Carbon for Enhanced CO2 Capture and Supercapacitor Performance

An innovative technique to obtain high-surface-area mesostructured carbon (2545m(2)g(-1)) with significant microporosity uses Teflon as the silica template removal agent. This method not only shortens synthesis time by combining silica removal and carbonization in a single step, but also assists in ultrafast removal of the template (in 10min) with complete elimination of toxic HF usage. The obtained carbon material (JNC-1) displays excellent CO2 capture ability (ca. 26.2wt% at 0 degrees C under 0.88bar CO2 pressure), which is twice that of CMK-3 obtained by the HF etching method (13.0wt%). JNC-1 demonstrated higher H-2 adsorption capacity (2.8wt%) compared to CMK-3 (1.2wt%) at -196 degrees C under 1.0bar H-2 pressure. The bimodal pore architecture of JNC-1 led to superior supercapacitor performance, with a specific capacitance of 292Fg(-1) and 182Fg(-1) at a drain rate of 1Ag(-1) and 50Ag(-1), respectively, in 1m H2SO4 compared to CMK-3 and activated carbon.

No More HF: Teflon-Assisted Ultrafast Removal of Silica to Generate High-Surface-Area Mesostructured Carbon for Enhanced CO2 Capture and Supercapacitor Performance

An innovative technique to obtain high-surface-area mesostructured carbon (2545m(2)g(-1)) with significant microporosity uses Teflon as the silica template removal agent. This method not only shortens synthesis time by combining silica removal and carbonization in a single step, but also assists in ultrafast removal of the template (in 10min) with complete elimination of toxic HF usage. The obtained carbon material (JNC-1) displays excellent CO2 capture ability (ca. 26.2wt% at 0 degrees C under 0.88bar CO2 pressure), which is twice that of CMK-3 obtained by the HF etching method (13.0wt%). JNC-1 demonstrated higher H-2 adsorption capacity (2.8wt%) compared to CMK-3 (1.2wt%) at -196 degrees C under 1.0bar H-2 pressure. The bimodal pore architecture of JNC-1 led to superior supercapacitor performance, with a specific capacitance of 292Fg(-1) and 182Fg(-1) at a drain rate of 1Ag(-1) and 50Ag(-1), respectively, in 1m H2SO4 compared to CMK-3 and activated carbon.

Tiempo kairológico y tradición oculta: la recepción de Walter Benjamin por parte de Hannah Arendt

Introducción: "La investigación titulada Tiempo kairológico y tradición oculta. La recepción del pensamiento de Walter Benjamin por parte de Hannah Arendt propone el esclarecimiento de las cuestiones y de las actitudes teóricas que Hannah Arendt tomó, selectivamente, de Walter Benjamin. Ambos comparten la conciencia del colapso moral y político de la Europa de entreguerras, no menos que la desconfianza ante las categorías de juicio transmitidas por una tradición, a la que no juzgaban vinculante. Discuten los mecanismos compulsivos de la lógica y los juzgan estériles e impropios para comprender y valorar. Impugnan un concepto de historia al que consideran obsoleto e indebido para discernir el significado de las acciones e inadecuado para dar cuenta de la novedad y el acontecimiento. En consecuencia, ambos recalan en “el fragmento y la ruina”, y enaltecen eventos olvidados y des-asidos del contexto referencial habitual. Así, presentan una historiografía fragmentada, compatible con una concepción del tiempo como origen y acontecimiento o, también, como disrupción de la linealidad cronológica. A esta noción llamamos tiempo kairológico..."

Fieles divorciados, segundas uniones more coniugale y administración de la penitencia y la eucaristía

Resumen: La vida sacramental de los fieles divorciados, que viven en una segunda unión a modo matrimonial o también llamados “vueltos a casar” en un tema que viene reflexionándose en la Iglesia. Si bien con diversas acentuaciones, se confirma la importancia de que toda reflexión cuente con un marco de profunda renovación espiritual, a la luz del misterio de Cristo, con quien el cristiano está llamado a conformarse.

Hannah Arendt y Walter Benjamin : masa, multitud, populacho

Resumen: Hannah Arendt y Walter Benjamin examinan los fenómenos asociativos de masa, multitud y populacho. Ambos sustraen tales grupos del ámbito político y los sitúan en el ámbito social. En Los orígenes del totalitarismo, Arendt indaga la noción de populacho o mob en el contexto del fenómeno imperialista. Asocia el carácter del populacho con el de la clase burguesa y posiciona ambos grupos en la emergencia de los nacionalismos tribales, ambos antecesores del totalitarismo. La masa es consustancial con los regímenes totalitarios. La apatía cívica, el cinismo y el derrumbe de las costumbres burguesas no alcanzan para explicar el fenómeno totalitario. El hombre masa ha perdido incluso el interés por sí mismo y el gusto por las asociaciones no partidarias. Walter Benjamin reflexiona literariamente los fenómenos de la bohème y de la multitud (crowd), a través de la poesía de Baudelaire y los relatos de Poe. El primer grupo incluye los conspiradores profesionales, cuyo aislamiento y resentimiento los emparenta con los miembros del mob. La falta de pertenencia y la ausencia de vínculos los conduce al activismo, sin un programa de acción. En el contexto de su reflexión sobre el fenómeno de la multitud, Benjamin indaga el impacto de las condiciones de vida moderna en las conductas automatizadas de los individuos. Los comportamientos reflejos, las respuestas automatizadas y los clichés, son las notas que también Arendt encuentra en el hombre “normal” y diluido en la masa, como lo evidenció la conducta de Eichmann durante el proceso en Jerusalén