Fracture Gradient
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Influences of Growth Velocity and Fe Content on Microstructure, Microhardness and Tensile Properties of Directionally Solidified Al-1.9Mn-xFe Ternary Alloys
In this study, influences of growth velocity and composition (Fe content) on the microstructure (rod spacing) and mechanical properties (microhardness, ultimate tensile strength and fracture surface) of Al-Mn-Fe ternary alloys have been investigated. Al-1.9 Mn-xFe (x=0.5, 1.5 and 5 wt. %) were prepared using metals of 99.99% high purity in the vacuum atmosph
Mat. Res.. Publicado em: 11/05/2017
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2. Workhardening behaviour and microstructural analysis of failed austenitic manganese steel crusher jaws
This study focussed on the work hardening behaviour and microstructure of austenitic manganese steel relative to premature failure of crusher jaws. Samples of sound and failed crusher jaws were taken, the change with depth from the working surface to the sample core was measured and their microstructures observed. The study revealed a sharp hardness gradient
Mat. Res.. Publicado em: 03/09/2013
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3. Novo método para estimativa do gradiente de fratura para poços de petróleo
The development of oil wells drilling requires additional cares mainly if the drilling is in offshore ultra deep water with low overburden pressure gradients which cause low fracture gradients and, consequently, difficult the well drilling by the reduction of the operational window. To minimize, in the well planning phases, the difficulties faced by the dril
Publicado em: 2010
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4. Fadiga térmica de ferros fundidos brancos multicomponentes. / Thermal fatigue of multicomponent white cast iron.
The effects of the volume fraction of eutectic carbides and of the matrix hardness on the thermal fatigue resistance of multicomponent white cast iron were investigated. Alloys Fe-4Cr-V-2Mo-2W-2C, V ranging from 5 to 8 wt% and Fe-4Cr-8V-Mo-2W-2C, Mo ranging from 2 to 5 wt % were used. Disc shaped samples were quench and tempered for obtaining two matrix micr
Publicado em: 2003
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5. Estudo hidrologico, hidrogeologico e geofisico no municipio de Itamonte-MG
The principal objective of this dissertation was to use hydrological, hydrogeological and geophysica1 techniques to study the behavior of springs in a hydrographic microbasin; a secondary objective was the verification of the usefulness of a geophysical technique for the location of bore wells in crysta11ine rocks in embasement areas. The area studied is loc
Publicado em: 2001
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6. Compartment syndrome as a complication of a stab wound to the thigh: a case report and review of the literature
Acute compartment syndrome of the thigh is a rare but potentially devastating condition, in which the pressure within the osseofascial compartment rises above the capillary perfusion gradient, leading to cellular anoxia, muscle ischaemia and death. Early diagnosis and treatment is essential to prevent long term disability. It is most often associated with cr
BMJ Group.
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7. Incorporation of influenza virus M-protein into liposomes.
M-protein from influenza virus vaccine was purified by sodium dodecyl sulfate-gel chromatography and incorporated into liposomes by solubilization with octylglucoside and subsequent dialysis. Liposomes containing M-protein formed a distinct population with a density of 1.22 g/ml on sucrose-gradient centrifugation, regardless of the net charge on the liposome
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8. Distribution of crystals in the superficial zone of elderly human articular cartilage of the femoral head in subcapital fracture.
Crystal distribution in articular cartilage of femoral heads resected at hip arthroplasty for fracture of the femoral neck was examined in 10 patients (77-91 years) by computerised image analysis of electron micrographs. Crystal content of the zenith did not differ from that of the infrafoveal region of the femoral head in the superficial 0.5 mm of the carti
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9. Characterization of outer membranes isolated from Treponema pallidum, the syphilis spirochete.
Previous freeze-fracture electron microscopy (EM) studies have shown that the outer membrane (OM) of Treponema pallidum contains sparse transmembrane proteins. One strategy for molecular characterization of these rare OM proteins involves isolation of T. pallidum OMs. Here we describe a simple and extremely gentle method for OM isolation based upon isopycnic
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10. Relationship of aggregated intramembranous particles to water permeability in vasopressin-treated toad urinary bladder.
It has been previously demonstrated with freeze-fracture electron microscopy that vasopressin induces specific structural alterations of the luminal membrane of granular cells from toad urinary bladder in a dose-dependent fashion. These alterations consist of aggregated intramembranous particles and are observed both in the presence and absence of an osmotic
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11. Shape change and physical properties of giant phospholipid vesicles prepared in the presence of an AC electric field.
Giant unilamellar vesicles with diameters ranging from 10 to 60 microns were obtained by the swelling of phospholipid bilayers in water in the presence of an AC electric field. This technique leads to a homogeneous population of perfectly spherical and unilamellar vesicles, as revealed by phase-contrast optical microscopy and freeze-fracture electron microsc
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12. Some Characteristics of the Outer Membrane Material Released by Growing Enterotoxigenic Escherichia coli
The high-molecular-weight material released into the medium by Escherichia coli AP1, an enterotoxigenic strain of porcine origin, has been isolated and resolved into two clearly distinct fractions, based on sucrose density gradient and differential centrifugation, chemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and freeze-fractu