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1.
A new seismic support device and its application in piping systems is described. The device, E-BAR (patented), can be cost effectively used for snubber replacement programs, mitigation of hydraulic transients, pipe whip and as a thermal stop. The device has pre-set gaps to allow free thermal movement. During a seismic or other dynamic load event, if the pipe movement exceeds the gap dimension, the device acts as an elastic or elastic-plastic restraint. The device also has a unique design feature for not exceeding the restraint force beyond a specified limit design value. To analyze piping systems with gap supports having elastic-plastic characteristics, modal analysis procedures for both response spectrum and time history methods are developed. The comparison of responses obtained from the procedures with nonlinear time history analysis and test results available in the literature shows excellent correlation. A pilot program conducted for snubber replacement with E-BARs demonstrates that the limit force feature of E-BAR makes them very attractive for snubber replacement. This is because a particular E-BAR with a specified limit design force can be selected, such that, the E-BAR replacing the snubber does not require any modifications be made to the existing support steel and hardware. 相似文献
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The results of X-rays, electrical resistivities and magnetic studies performed on Y−x
Zr
x
Ba2Cu3Ot7−δ and Y1−2x
Zr
x
Eu
x
Ba2Cu3O7−δ superconducting compounds, in the temperature range 4.2–500 K and external fields up to 50 kOe are reported. The presence
of zirconium decreases the superconducting transition temperatures,T
c. BelowT
c, the hysteresis loops narrow when the zirconium content increases. From the magnetization curves, the critical current densities
were determined. A time dependence of the magnetizations of logarithmic form was found. The flux-pinning energy was estimated
to beU ≃0.03 eV. Above the transition temperatures, Y−x
Zr
x
Ba2Cu3Ot7−δ samples show a Pauli-type paramagnetism, while Y1−2x
Zr
x
Eu
x
Ba2Cu3O7−δ compounds have, in addition, temperature-dependent contributions to the magnetic susceptibilities. The effective europium
moments are ∼3.40 μB suggesting that the ion is in (+3) valence state. 相似文献
5.
The nonsimilar and self-similar flows for the steady natural convection over a vertical heated surface in a saturated porous medium with mass transfer using non-Darcy model have been studied under boundary layer approximations. The differential equations governing both the nonsimilar and self-similar flows have been solved numerically using an implicit finite-difference scheme developed by Keller. The results indicate that both heat transfer and velocity field are appreciably affected by the modified Grashof number and mass transfer except that the effect of the modified Grashof number on the heat transfer for large suction is very small. It is found that the maximum velocity occurs at the wall and it increases as the modified Grashof number or injection increases. 相似文献
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Nicotin und Ioan D. Vldescu 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1938,75(5):450-457
Ohne Zusammenfassung 相似文献
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Neural Computing and Applications - The impact of viscous dissipation in hybrid nanofluid plays a prominent role in industrial applications, for instance, in polymer processing flows and... 相似文献
10.
Maria Bercea Silvia Ioan Bogdan C. Simionescu Cristofor I. Simionescu 《Polymer Bulletin》1992,27(5):571-575
Summary Systematic studies on solution properties of ultrahigh molecular weight polymers showed the existence of some special features as compared to usual length polymers. The paper discusses the possible appearance of branched structures in the polymerization process, structures able to influence the mentioned features. From experimental data on poly(methyl methacrylate), poly(butyl methacrylate) and polyacrylonitrile it appears that branching can be excluded, and the very high molecular weight domain considered may be responsible for the modifications observed in the molecular weight dependences on 2>, A2 or []. 相似文献