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This paper evaluates in-soil tensile load-strain characteristics of geogrids with the help of a custom designed and developed in-soil tensile setup in the laboratory. Displacement controlled in-soil tensile tests were carried out to evaluate the effect of normal stress, soil type, and presence of sand-sandwiched layer, on the tensile load-strain characteristics of geogrid. Confinement of geogrid within the soil and application of normal stress were found to increase the mobilized tensile load and secant tensile stiffness of geogrid. Secant stiffness improvement factors were determined to quantify the improvement in tensile load-strain characteristics of geogrid under confinement, on comparison to in-isolation values. Geogrid was observed to exhibit lower secant tensile stiffness when embedded in marginal soil, moist-compacted at wet of optimum. However, the concept of sand-sandwiched geogrid was found to improve the tensile load-strain behaviour of geogrids embedded in marginal soil compacted at wet of optimum. 相似文献
34.
A. Jallipalli G. Balakrishnan S. H. Huang T. J. Rotter K. Nunna B. L. Liang L. R. Dawson D. L. Huffaker 《Nanoscale research letters》2009,4(12):1458-1462
We report structural analysis of completely relaxed GaSb epitaxial layers deposited monolithically on GaAs substrates using
interfacial misfit (IMF) array growth mode. Unlike the traditional tetragonal distortion approach, strain due to the lattice
mismatch is spontaneously relieved at the heterointerface in this growth. The complete and instantaneous strain relief at
the GaSb/GaAs interface is achieved by the formation of a two-dimensional Lomer dislocation network comprising of pure-edge
(90°) dislocations along both [110] and [1-10]. In the present analysis, structural properties of GaSb deposited using both
IMF and non-IMF growths are compared. Moiré fringe patterns along with X-ray diffraction measure the long-range uniformity
and strain relaxation of the IMF samples. The proof for the existence of the IMF array and low threading dislocation density
is provided with the help of transmission electron micrographs for the GaSb epitaxial layer. Our results indicate that the
IMF-grown GaSb is completely (98.5%) relaxed with very low density of threading dislocations (105 cm−2), while GaSb deposited using non-IMF growth is compressively strained and has a higher average density of threading dislocations
(>109 cm−2). 相似文献
35.
Jaydeep Balakrishnan Chun-Hung Cheng Kin-Chuen Ho Kum Khiong Yang 《Journal of Manufacturing Systems》2009
U-lines have been adopted in many manufacturing settings as part of JIT implementation. In this paper, we examine the applicability of existing straight-line heuristics for obtaining a balance on a U-line. We modify 13 single-pass heuristics and study the effectiveness of various heuristics under different problem conditions. An extensive computational study is carried out to help identify the best heuristics. In addition, we compare recent U-line procedures with a single-pass heuristic using some literature problems. Based on a single-pass heuristic, we compare the configurations of a straight- and U-line. 相似文献
36.
Manoj Gaur Jaya Lohani R. Raman V.R. Balakrishnan P. Raghunathan S.V. Eswaran 《Synthetic Metals》2010,160(19-20):2061-2064
Diode devices (glass/ITO/polymer/Al) have been fabricated using poly (3-hexylthiophene) (P3HT) crosslinked with two different biaryl crosslinkers. Crosslinking was performed by exposing the thin films with different wt% of crosslinker to UV irradiation and progress of crosslinking was monitored by IR spectroscopy. An increase in hole mobility of two orders of magnitude has been observed after crosslinking. 相似文献
37.
Quantum-dot cellular automata (QCA) is one of the promising nextgeneration fabrics for circuits. Coplanar wire crossings are one of the more elegant features of this new low-power computing paradigm. Proposed are coplanar wire crossovers using a single type of QCA cells, which has significant implications in fabrication and fault tolerance. 相似文献
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Panel count data usually refer to data arising from studies on recurrent events in which the subjects under study are followed
or observed only periodically rather than continuously. In such situations, an objective of interest is about the occurrence
of some events that can occur multiple times or repeatedly and the studies resulting in this type of information are often
referred to as event history studies. There are many fields such as medical studies, reliability experiments and social sciences
wherein panel count data are encountered commonly. This article reviews basic concepts about panel count data, some common
issues and questions of interest regarding them as well as the corresponding statistical procedures that are suitable for
their analysis. In particular, we will discuss an estimation of the mean function of the underlying counting process characterizing
the occurrence of the events, comparison of several processes and analysis of multiple state panel count data. Some discussion
is also presented of situations involving dependent or informative observation processes. 相似文献
40.
For the half-logistic distribution the maximum likelihood method does not provide an explicit estimator for the scale parameter based on either complete or right-censored samples. The authors provide a simple method of deriving an explicit estimator by approximating the likelihood function. The bias and variance of this estimator are studied, and it is shown that this estimator is as efficient as the best linear unbiased estimator. An example to illustrate the method is presented 相似文献