87,740 research outputs found
Lubrication handbook
Information on lubricants from government reports, military specifications, qualified parts lists, and suppliers of commercial lubricants has been consolidated in one source. Handbook includes data on chemical and physical properties of solid, bonded solid, and liquid lubricants; dispersions and composites; and greases, oils, and hydraulic fluids
Strain-age cracking in Rene 41 alloy
Weldability test determines the effects of material and process variables on the occurrence of strain-age cracking, and demonstrates effective and practical means for its reduction. Studies consist of tensile, impact, and stress-rupture tests
In-migrants and exclusion in east African rangelands: access, tenure and conflict
East African rangelands have a long history of population mobility linked to competition over key resources, negotiated access, and outright conflict. Both in the literature and in local discourse, in-migration is presented as leading to increased competition, driving poverty and social exclusion on the one hand, and conflict and violence on the other. Current analyses in developing countries identify economic differences, ethnic fault lines, ecological stresses and a breakdown in state provision of human and constitutional rights as factors in driving conflict. The present paper explores this interaction of in-migration and conflict with respect to Kenyan and Tanzanian pastoralist areas and populations. Using quantitative and qualitative methods, patterns of resource access and control in Kenya and Tanzania Maasailand are explored in terms of the ways land and livestock are associated with migration status, ethnicity and wealth or political class. Contrasts and similarities between the two national contexts are used to develop a better understanding of the ways these factors operate under different systems of tenure and access. The conclusion briefly considers implications of these patterns, their potential for exacerbating poverty, and policies for minimising social exclusion and conflict in East African rangelands. / Abstract in French: Les prairies d'Afrique orientale connaissent depuis longtemps une mobilité des populations, liée aux problèmes de concurrence pour les ressources clés, d'accès négocié et de conflits pures et simples. Dans la littérature comme dans le discours local, l'immigration interne est présentée comme cause de concurrence accrue, motrice de pauvreté et d'exclusion sociale d'une part, et de conflit et de violence d'autre part. Des analyses menées actuellement dans les pays en développement identifient comme facteurs moteurs de conflit des écarts économiques, des failles ethniques, des tensions écologiques et une détérioration des droits humains et constitutionnels. Cet article examine l'interaction entre immigration interne et conflit au sein des régions et populations pastorales du Kenya et de la Tanzanie. Il utilise des méthodes quantitatives et qualitatives pour étudier les modèles d'accès et de contrôle des ressources dans le pays masaï du Kenya et de la Tanzanie en termes d'association des terres et du bétail au statut d'immigration, à l'ethnicité et à la catégorie de richesse ou politique. Les contrastes et similarités entre les deux contextes nationaux servent à mieux comprendre le mode de fonctionnement de ces facteurs dans des régimes fonciers et systèmes d'accès différents. La conclusion examine brièvement les implications de ces modèles, leur capacitéà exacerber la pauvreté et les politiques de minimisation de l'exclusion sociale et des conflits dans les prairies d'Afrique orientale
Irrelevant Exceptional Divisors for Curves on a Smooth Surface
Given a singular curve on a smooth surface, we determine which exceptional
divisors on the minimal resolution of that curve contribute toward its jumping
numbers.Comment: Added reference to Favre & Jonsson and a slight extension of the
comment immediately following Definition 2.
Search for Contact Interactions in the Dimuon Final State at ATLAS
The Standard Model has been successful in describing many fundamental aspects
of particle physics. However, there are some remaining puzzles that are not
explained within the context of its present framework. We discuss the
possibility to discover new physics in the ATLAS Detector via a four-fermion
contact interaction, much in the same way Fermi first described Weak
interactions. Using a simple ratio method on dimuon events, we can set a 95%
C.L. lower limit on the effective scale Lambda = 7.5 TeV (8.7 TeV) for the
constructive Left-left Isoscalar Model of quark compositeness with 100 pb^-1
(200 pb^-1) of data at sqrt{s} = 10 TeV.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July
2009, eConf C09072
Research on graphite reinforced glass matrix composites
A broad group of fibers and matrices were combined to create a wide range of composite properties. Primary material fabrication procedures were developed which readily permit the fabrication of flat plate and shaped composites. Composite mechanical properties were measured under a wide range of test conditions. Tensile, flexure mechanical fatigue, thermal fatigue, fracture toughness, and fatigue crack growth resistance were evaluated. Selected fiber-matrix combinations were shown to maintain their strength at up to 1300 K when tested in an inert atmosphere. Composite high temperature mechanical properties were shown to be limited primarily by the oxidation resistance of the graphite fibers. Composite thermal dimensional stability was measured and found to be excellent
Arlis/ANZ 2.0
We've all been hearing about Web 2.0 and Library 2.0 lately. But just what are they all about, and is there anything there that Arlis/ANZ can take advantage of in order to better go about its business? Can there, should there, be an Arlis/ANZ 2.0? Arlis/ANZ, the Arts Libraries Society of Australia and New Zealand, is preparing to review it's online prescence. The Arlis/ANZ website is now three years old, and has been well maintained during that time. However it has not yet been systematically reviewed in terms of content, functionality, and strategic direction. The Arlis/ANZ Website version 'One' will be redeveloped into Arlis/ANZ Website version 'Two'. Although much of that review will concentrate on the structure, look and feel of the site, the review process offers an opportunity to incorporate Web 2.0 developments. By incorporating that 'best' of Web 2.0 in a strategic manner, Arlis/ANZ 2.0 - the website - has powerful potential to contribute toward the strength, cohesion and ongoing development of Arlis/ANZ 2.0 - the Society
Method of purifying metallurgical grade silicon employing reduced pressure atmospheric control
A method in which a quartz tube is charged with chunks of metallurgical grade silicon and/or a mixture of such chunks and high purity quartz sand, and impurities from a class including aluminum, boron, as well as certain transition metals including nickel, iron, and manganese is described. The tube is then evacuated and heated to a temperature within a range of 800 C to 1400 C. A stream of gas comprising a reactant, such as silicon tetrafluoride, is continuously delivered at low pressures through the charge for causing a metathetical reaction of impurities of the silicon and the reactant to occur for forming a volatile halide and leaving a residue of silicon of an improved purity. The reactant which included carbon monoxide gas and impurities such as iron and nickel react to form volatile carbonyls
Constraining the Surface Inhomogeneity and Settling Times of Metals on Accreting White Dwarfs
Due to the short settling times of metals in DA white dwarf atmospheres, any
white dwarfs with photospheric metals must be actively accreting. It is
therefore natural to expect that the metals may not be deposited uniformly on
the surface of the star. We present calculations showing how the temperature
variations associated with white dwarf pulsations lead to an observable
diagnostic of the surface metal distribution, and we show what constraints
current data sets are able to provide. We also investigate the effect that
time-variable accretion has on the metal abundances of different species, and
we show how this can lead to constraints on the gravitational settling times.Comment: 4 pages, 5 figures, accepted for publication in the Astrophysical
Journal Letters, updated reference
Two neutron decay of 16Be
Recently, the first example of two-neutron decay from the ground state of an
unbound nucleus, Be, was seen. Three-body methods are ideal for exactly
treating the degrees of freedom important for these decays. Using a basis
expansion over hyperspherical harmonics and the hyperspherical R-matrix method,
we construct a realistic model of Be in order to investigate its decay
mode and the role of the two-neutron interaction. The neutron-Be
interaction is constrained using shell model predictions. We obtain a ground
state for Be that is over-bound by approximately 1 MeV with a width of
approximately 0.23 MeV. This suggests, that for such systems, the three-body
force needs to be repulsive.Comment: 4 pages, 1 figure, contribution to the proceedings for the 21st
International Conference on Few Body Problems in Physics, Chicago, Illinois,
US
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