http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Dynamic analysis of trusses including the effect of local modes
Levy, Eldad,Eisenberger, Moshe Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.7 No.1
The dynamic analysis of trusses using the finite element method tends to overlook the effect of local member dynamic behavior on the overall response of the complete structure. This is due to the fact that the lateral inertias of the members are omitted from the global inertia terms in the structure mass matrix. In this paper a condensed dynamic stiffness matrix is formulated and used to calculate the exact dynamic properties of trusses without the need to increase the model size. In the examples the limitations of current solutions are presented together with the exact results obtained from the proposed method.
Photoluminescence of heavily doped, compensated Si:P, B
Levy, Miguel,Yu, P. Y.,Zhang, Youzhu,Sarachik, M. P. 순천대학교 기초과학연구소 1994 基礎科學硏究誌 Vol.5 No.-
We present a systematic experimental investigation of the photoluminescence of heavily doped, compensated Si:P,B. The spectra broaden as the doping levels are increased, as expected. The spectral weights of the no-phonon peak and the phonon-assisted transitions vary with compensation and with excitation intensity. In contrast with the simple superposition of high-level and low-level spectra found for uncompensated material, increasing the input power for heavily doped, compensated Si produces a strong, continuous shift in energy of the entire spectrum in an essentially rigid way. A logarithmic power dependence found for the two most heavily doped samples is consistent with an exponential band tail. Deviations from this behavior are found for two samples with lower concentration and compensation. We suggest that these deviations may signal the onset of a minimum in the density of states that occurs when the acceptor (donor) band begins to separate from the host valence (conduction) band as the dopant concentration is reduced.
Rayleigh-Ritz optimal design of orthotropic plates for buckling
Levy, Robert Techno-Press 1996 Structural Engineering and Mechanics, An Int'l Jou Vol.4 No.5
This paper is concerned with the structural optimization problem of maximizing the compressive buckling load of orthotropic rectangular plates for a given volume of material. The optimality condition is first derived via variational calculus. It states that the thickness distribution is proportional to the strain energy density contrary to popular claims of constant strain energy density at the optimum. An engineers physical meaning of the optimality condition would be to make the average strain energy density with respect to the depth a constant. A double cosine thickness varying plate and a double sine thickness varying plate are then fine tuned in a one parameter optimization using the Rayleigh-Ritz method of analysis. Results for simply supported square plates indicate an increase of 89% in capacity for an orthotropic plate having 100% of its fibers in $0^{\circ}$ direction.
Levy, Richard H.,Dunbar, Gavin B.,Vandergoes, Marcus J.,Howarth, Jamie D.,Kingan, Tony,Pyne, Alex R.,Brotherston, Grant,Clarke, Michael,Dagg, Bob,Hill, Matthew,Kenton, Evan,Little, Steve,Mandeno, Darc Copernicus GmbH 2018 Scientific drilling Vol.24 No.-
<P><p><strong>Abstract.</strong> A new annually resolved sedimentary record of Southern Hemisphere mid-latitude hydroclimate was recovered from Lake Ohau, South Island, New Zealand, in March 2016. The Lake Ohau Climate History (LOCH) project acquired cores from two sites (LOCH-1 and -2) that preserve sequences of laminated mud that accumulated since the lake formed <span class='inline-formula'>∼</span><span class='thinspace'></span>17<span class='thinspace'></span>000 years ago. Cores were recovered using a purpose-built barge and drilling system designed to recover soft sediment from thick sedimentary sequences in lake systems up to 150<span class='thinspace'></span>m deep. This system can be transported in two to three 40<span class='thinspace'></span>ft long shipping containers and is suitable for use in a range of geographic locations. A comprehensive suite of data has been collected from the sedimentary sequence using state-of-the-art analytical equipment and techniques. These new observations of past environmental variability augment the historical instrumental record and are currently being integrated with regional climate and hydrological modelling studies to explore causes of variability in extreme/flood events over the past several millennia.</p> </P>
Beneficial Effects of Flavonoids on Skeletal Muscle Health: A Systematic Review and Meta-Analysis
Levy Munguı´a,Cristian Gonza´lez,Andre´s Portilla,Eduardo Meaney,Francisco Villarreal,Nayelli Na´jera,Guillermo Ceballos 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.5
Skeletal muscle (SkM) is a highly dynamic tissue that responds to physiological adaptations or pathological conditions, and SkM mitochondria play a major role in bioenergetics, regulation of intracellular calcium homeostasis, pro-oxidant/antioxidant balance, and apoptosis. Flavonoids are polyphenolic compounds with the ability to modulate molecular pathways implicated in the development of mitochondrial myopathy. Therefore, it is pertinent to explore its potential application in conditions such as aging, disuse, denervation, diabetes, obesity, and cancer. To evaluate preclinical and clinical effects of flavonoids on SkM structure and function. We performed a systematic review of published studies, with no date restrictions applied, using PubMed and Scopus. The following search terms were used: “flavonoids” OR “flavanols” OR “flavones” OR “anthocyanidins” OR “flavanones” OR “flavan-3-ols” OR “catechins” OR “epicatechin” OR “(−)-epicatechin” AND “skeletal muscle.” The studies included in this review were preclinical studies, clinical trials, controlled clinical trials, and randomized-controlled trials that investigated the influence of flavonoids on SkM health. Three authors, independently, assessed trials for the review. Any disagreement was resolved by consensus. The use of flavonoids could be a potential tool for the prevention of muscle loss. Their effects on metabolism and on mitochondria function suggest their use as muscle regulators.