The development of new, low-cost perfluoroalkylether fluids with excellent low and high-temperature properties

A series of perfluoroalkylether (PFAE) fluids were synthesized by direct fluorination. Viscosity-temperature properties, oxidation stabilities, oxidation-corrosion properties, and lubricity were determined. The fluids were tested in the presence of common elastomers to check for compatibility. The bulk modulus of each was measured to determine if any could be used as nonflammable aircraft hydraulic fluid. It was determined that as the carbon to oxygen ratio decreases, the viscometric properties improve, the fluids may become poor lubricants, the bulk modulus increases, the surface tension increases, and the fluid density increases. The presence of difluoromethylene oxide units in the polymer does not seriously lower the oxidation and oxidation-corrosion stabilities as long as the difluoromethylene oxide units are separated by other units

The preparation of new perfluoroether fluids exhibiting excellent thermal-oxidative stabilities

A series of low molecular weight perfluoroalkylethers (PFAE) were synthesized by direct fluorination. Viscosity-temperature properties and oxidation stabilities were determined. Viscosity-temperature correlations indicated that increases in branching and increases in the size of the branching substituent caused a deterioration in viscometric properties (i.e., an increase in ASTM slope). In addition, increasing the ratio of carbon to oxygen in these compounds also increased the ASTM slope. Preliminary oxidation stability tests indicated that highly branched PFAE fluids. (i.e., those containing quaternary carbons) may be less stable than either those containing a single trifluoromethyl pendant group or those containing no branching at all

Direct observation of substitutional Ga after ion implantation in Ge by means of extended x-ray absorption fine structure

We present an experimental lattice location study of Ga atoms in Ge after ion implantation at elevated temperature (250°C). Using extended x-rayabsorption fine structure (EXAFS) experiments and a dedicated sample preparation method, we have studied the lattice location of Ga atoms in Ge with a concentration ranging from 0.5 at. % down to 0.005 at. %. At Ga concentrations ≤0.05 at.%, all Ga dopants are substitutional directly after ion implantation, without the need for post-implantation thermal annealing. At higher Ga concentrations, a reduction in the EXAFS amplitude is observed, indicating that a fraction of the Ga atoms is located in a defective environment. The local strain induced by the Ga atoms in the Ge matrix is independent of the Ga concentration and extends only to the first nearest neighbor Ge shell, where a 1% contraction in bond length has been measured, in agreement with density functional theory calculations.We acknowledge the support from the Research Foundation Flanders, the epi-team from imec, the KU Leuven GOA 09/06 project, the IUAP program P6/42 and the Australian Research Council. S.C. acknowledges support from OCAS NV by an OCAS-endowed chair at Ghent University

Physical and chemical properties of some new perfluoropolyalkylether lubricants prepared by direct fluorination

A series of perfluoropolyalkylether (PFPAE) fluids was synthesized by direct fluorination. Viscosity-temperature properties, oxidation stabilities, oxidation-corrosion properties, bulk modulus, lubricity, surface tension and density were measured. It was shown that as the carbon to oxygen ratio in the polymer repeating unit decreases, the viscometric properties improve, the fluids may become poorer boundary lubricants, the bulk modulus increases, the surface tension increases and the fluid density increases. The presence of difluoromethylene oxide units in the polymer does not significantly lower the oxidation and oxidation-corrosion stabilities as long as the difluoromethylene oxide units are separated by other units

Fish and Feminists

Summary Despite apparent acceptance of gender analysis within development organizations, this is still only rarely translated into gender?sensitive practice. The language of gender and development is adopted, but is accompanied by a subtle shift into ‘projects for women’. The article considers the problem through a case study of a programme in one international development organization – the FAO. The programme promotes small scale fish farming in southern Africa, and gender issues have gained a high profile in its stated aims. The case study traces the articulation of gender issues from headquarters to a pilot project in Luapula Province, Zambia. RESUME La pisciculture au féminin En dépit de l'acceptation apparemment répandue de l'analyse du genre dans les organisations développementales, il est rare que cette analyse soit consacrée dans des pratiques qui respectent le genre. S'il est vrai que le langage du genre et du développement est adopté, l'on constate d'un autre côté un décalage subtil vers les “projets pour femmes”. Le présent article s'adresse à ce problème par le biais d'une étude de cas basée sur un programme mené par une organisation internationale de développement – la FAO. Le programme concerné organise des projets de pisciculture de petite envergure en Afrique australe, et les questions du genre occupent une place d'importance dans ses objectifs déclarés. L'étude de cas trace l'articulation des questions du genre à partir du siège et jusqu'à un projet pilote organisé dans la province de Luapula en Zambie. RESUMEN ‘Fish and feminists’ A pesar de la aparente aceptación del análisis de género dentro de las organizaciones de desarrollo, esta aceptación rara vez se traduce en prácticas sensibles a la cuestión. Se adopta el lenguaje de género y desarrollo, pero al mismo tiempo se produce un sutil cambio de dirección hacia proyectos para la mujer. Este artículo considera el problema a través del estudio de un programa de una organización internacional de desarrollo – la FAO. Este programa promueve piscifactorías en pequeña escala en Africa del Sur, y los tópicos de género han ganado mucha importancia ensus objetivos establecidos. El estudio de este caso analiza paso a paso la articulación de las cuestiones de género desde las oficinas centrales hasta un proyecto piloto en la provincia de Luapula, en Zambia

An efficient algorithm to calculate intrinsic thermoelectric parameters based on Landauer approach

The Landauer approach provides a conceptually simple way to calculate the intrinsic thermoelectric (TE) parameters of materials from the ballistic to the diffusive transport regime. This method relies on the calculation of the number of propagating modes and the scattering rate for each mode. The modes are calculated from the energy dispersion (E(k)) of the materials which require heavy computation and often supply energy relation on sparse momentum (k) grids. Here an efficient method to calculate the distribution of modes (DOM) from a given E(k) relationship is presented. The main features of this algorithm are, (i) its ability to work on sparse dispersion data, and (ii) creation of an energy grid for the DOM that is almost independent of the dispersion data therefore allowing for efficient and fast calculation of TE parameters. The inclusion of scattering effects is also straight forward. The effect of k-grid sparsity on the compute time for DOM and on the sensitivity of the calculated TE results are provided. The algorithm calculates the TE parameters within 5% accuracy when the K-grid sparsity is increased up to 60% for all the dimensions (3D, 2D and 1D). The time taken for the DOM calculation is strongly influenced by the transverse K density (K perpendicular to transport direction) but is almost independent of the transport K density (along the transport direction). The DOM and TE results from the algorithm are bench-marked with, (i) analytical calculations for parabolic bands, and (ii) realistic electronic and phonon results for $Bi_{2}Te_{3}$.Comment: 16 Figures, 3 Tables, submitted to Journal of Computational electronic

Особенности фразеологического варианта в английском, немецком и шведском языках

Объект исследования – фразеология английского, немецкого и шведского языков, предмет изучения – характер вариантности ФЕ, цель исследования – выявление изоморфизма структурной организации германской фразеологии и вариантности посредством выполнения задач сопоставительного анализа, позволяющего выделить различные типы вариантов ФЕ в каждом из рассматриваемых германских языков

New Forms of Development: Branding Innovative Ideas and Bidding for Foreign Aid in the Maternal and Child Health Service in Nepal

Nepal has been receiving foreign aid since the early 1950s. Currently, the country’s health care systemis heavily dependent on aid, even for the provision of basic health services to its people. Globally, the mechanismfor the dispersal of foreign aid is becoming increasingly complex. Numerous stakeholders are involved at variouslevels: donors, intermediary organisations, project-implementing partners and the beneficiaries, engaging not onlyin Nepal but also globally. To illustrate how branding and bidding occurs, and to discuss how this process hasbecome increasingly vital in securing foreign aid to run MCH activities in Nepal

Extracellular MRP8/14 is a regulator of beta 2 integrin-dependent neutrophil slow rolling and adhesion

Myeloid-related proteins (MRPs) 8 and 14 are cytosolic proteins secreted from myeloid cells as proinflammatory mediators. Currently, the functional role of circulating extracellular MRP8/14 is unclear. Our present study identifies extracellular MRP8/14 as an autocrine player in the leukocyte adhesion cascade. We show that E-selectin-PSGL-1 interaction during neutrophil rolling triggers Mrp8/14 secretion. Released MRP8/14 in turn activates a TLR4-mediated, Rap1-GTPase-dependent pathway of rapid beta 2 integrin activation in neutrophils. This extracellular activation loop reduces leukocyte rolling velocity and stimulates adhesion. Thus, we identify Mrp8/14 and TLR4 as important modulators of the leukocyte recruitment cascade during inflammation in vivo