Striation Spacing
Mostrando 1-7 de 7 artigos, teses e dissertações.
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1. Estudo da inferência de carregamento em histórias de vôos simulados na liga de Al aeronáutico SAE-AMS 7475 T7351 / Loading study of inference in a simulated flights history using an SAE-AMS 7475 T7351 aluminum alloy.
The loading inference and the fractographic reconstruction of fatigue crack propagation rate in simulated flight stories, as Twist, mini-Twist, Falstaff and mini-Falstaff were investigated in this work. The studied material was an aluminum alloy SAE-AMS 7475 T7351. Tensile and hardness tests were carried out in order to determine mechanical properties, as we
Publicado em: 2007
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2. Correlação de estrias de fadiga com espectro de cargas em liga de Al aeronáutica SAE-AMS 7475 T 7351. / Correlation of fatigue striation spacing to loading history in aeronautic Al alloy, AMS 7475 T7351.
This work discusses the relationship between striation spacing, i.e. the microscopic crack propagation rate, SL (local) e SP (projected), as measured in post-mortem fractographic inspection of fatigue fractured surfaces, and the macroscopic crack propagation rate, da/dN, as monitored during fatigue crack growth tests. Compact tensile specimens C(T) were extr
Publicado em: 2003
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3. Control of sarcomere length in skinned muscle fibres of Rana temporaria during mechanical transients.
A new technique is described for high-speed measurement of striation spacing of single skinned muscle fibres. A galvanometer mirror directs helium-neon laser light on to the muscle fibre at a variable angle. Light diffracted by the cross-striations is collected by a position-sensitive photodetector. The incident angle necessary to centre the diffracted light
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4. Isolation and visualization of active presynaptic filaments of recA protein and single-stranded DNA.
In the presence of ATP, recA protein forms a presynaptic complex with single-stranded DNA that is an obligatory intermediate in homologous pairing. Presynaptic complexes of recA protein and circular single strands that are active in forming joint molecules can be isolated by gel filtration. These isolated active complexes are nucleoprotein filaments with the
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5. DNA packing in stable lipid complexes designed for gene transfer imitates DNA compaction in bacteriophage
The structure of complexes made from DNA and suitable lipids (lipoplex, Lx) was examined by cryo-electron microscopy (cryoEM). We observed a distinct concentric ring-like pattern with striated shells when using plasmid DNA. These spherical multilamellar particles have a mean diameter of 254 nm with repetitive spacing of 7.5 nm with striation of 5.3 nm width.
The National Academy of Sciences.
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6. Factors influencing the ascending limb of the sarcomere length-tension relationship in rabbit skinned muscle fibres.
1. The length dependence of Ca2+-activated tension within the ascending limb of the length-tension relationship, corresponding to sarcomere lengths below about 2.25 micron, was investigated in skinned fibres from rabbit psoas muscle. At high [Ca2+] a shallow phase and then a steep phase of tension decline were observed as sarcomere length was reduced, while
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7. Cross-bridge kinetics in the presence of MgADP investigated by photolysis of caged ATP in rabbit psoas muscle fibres.
1. The interaction between MgADP and rigor cross-bridges in glycerol-extracted single fibres from rabbit psoas muscle has been investigated using laser pulse photolysis of caged ATP (P3-1(2-nitrophenyl)ethyladenosine 5'-triphosphate) in the presence of MgADP and following small length changes applied to the rigor fibre. 2. Addition of 465 microM-MgADP to a r