Simulated Optimisation of Disordered Structures with negative Poisson’s ratios

Copyright © 2009 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Mechanics of Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Mechanics of Materials, Vol. 41 Issue 8 (2009). DOI: 10.1016/j.mechmat.2009.04.008Two-dimensional regular theoretical units that give a negative Poisson’s ratio (NPR) are well documented and well understood. Predicted mechanical properties resulting from these models are reasonably accurate in two dimensions but fall down when used for heterogeneous real-world materials. Manufacturing processes are seldom perfect and some measure of heterogeneity is therefore required to account for the deviations from the regular unit cells in this real-life situation. Analysis of heterogeneous materials in three dimensions is a formidable problem; we must first understand heterogeneity in two dimensions. This paper approaches the problem of finding a link between heterogeneous networks and its material properties from a new angle. Existing optimisation tools are used to create random two-dimensional topologies that display NPR, and the disorder in the structure and its relationship with NPR is investigated

Macromolecular theory of solvation and structure in mixtures of colloids and polymers

The structural and thermodynamic properties of mixtures of colloidal spheres and non-adsorbing polymer chains are studied within a novel general two-component macromolecular liquid state approach applicable for all size asymmetry ratios. The dilute limits, when one of the components is at infinite dilution but the other concentrated, are presented and compared to field theory and models which replace polymer coils with spheres. Whereas the derived analytical results compare well, qualitatively and quantitatively, with mean-field scaling laws where available, important differences from ``effective sphere'' approaches are found for large polymer sizes or semi-dilute concentrations.Comment: 23 pages, 10 figure

Understanding COVID-19-associated coagulopathy

COVID-19-associated coagulopathy (CAC) is a life-threatening complication of SARS-CoV-2 infection. However, the underlying cellular and molecular mechanisms driving this condition are unclear. Evidence supports the concept that CAC involves complex interactions between the innate immune response, the coagulation and fibrinolytic pathways, and the vascular endothelium, resulting in a procoagulant condition. Understanding of the pathogenesis of this condition at the genomic, molecular and cellular levels is needed in order to mitigate thrombosis formation in at-risk patients. In this Perspective, we categorize our current understanding of CAC into three main pathological mechanisms: first, vascular endothelial cell dysfunction; second, a hyper-inflammatory immune response; and last, hypercoagulability. Furthermore, we pose key questions and identify research gaps that need to be addressed to better understand CAC, facilitate improved diagnostics and aid in therapeutic development. Finally, we consider the suitability of different animal models to study CAC

Updated Nucleosynthesis Constraints on Unstable Relic Particles

We revisit the upper limits on the abundance of unstable massive relic particles provided by the success of Big-Bang Nucleosynthesis calculations. We use the cosmic microwave background data to constrain the baryon-to-photon ratio, and incorporate an extensively updated compilation of cross sections into a new calculation of the network of reactions induced by electromagnetic showers that create and destroy the light elements deuterium, he3, he4, li6 and li7. We derive analytic approximations that complement and check the full numerical calculations. Considerations of the abundances of he4 and li6 exclude exceptional regions of parameter space that would otherwise have been permitted by deuterium alone. We illustrate our results by applying them to massive gravitinos. If they weigh ~100 GeV, their primordial abundance should have been below about 10^{-13} of the total entropy. This would imply an upper limit on the reheating temperature of a few times 10^7 GeV, which could be a potential difficulty for some models of inflation. We discuss possible ways of evading this problem.Comment: 40 pages LaTeX, 18 eps figure

Adhesive Bonding of Polymeric Materials for Automotive Applications

In 1992, the Oak Ridge National Laboratory (ORNL) began a cooperative research program with the Automotive Composites Consortium (ACC) to develop technologies that would overcome obstacles to the adhesive bonding of current and future automotive materials. This effort is part of a larger Department of Energy (DOE) program to promote the use of lighter weight materials in automotive structures. By reducing the weight of current automobiles, greater fuel economy and reduced emissions can be achieved. The bonding of similar and dissimilar materials was identified as being of primary importance since this enabling technology gives designers the freedom to choose from an expanded menu of low-mass materials for structural component weight reduction. Early in the project`s conception, five key areas were identified as being of primary importance to the automotive industry

Stock Return, Volatility and Country Credit Risk: The Asia-Pacific Markets

近年來國際金融局勢詭譎多變，金融危機層出不窮，無論外資或有意投入國外股市的投資人都勢必更加小心。本研究乃針對亞太盆地國家的股票報酬率與國家信用水準變動做分析，並依開發中國家與已開發國家之別，嘗試探究其差異。本文的研究方法採用時間序列的模型(干預模型與衝擊反應分析)，檢定亞太盆地國家股票報酬率的時間序列型態，及國家信用變動對股票報酬率及其波動性的影響。實證結果顯示：1.無論開發中國家或已開發國家，其股票報酬率並不受自身股票報酬率的波動度影響，此結論恰與Baillie and Degennaro(1990)吻合。2.國家信用水準變動對股票報酬率的影響未落後達一個月之久。3.國家信用變動對已開發國家的股票報酬率及其波動度不具顯著的解釋力。4.國家信用改變對開發中國家股票報酬率及其波動度較具解釋力，但影響方向不一致，原因可能是開發中國家的投資障礙較多。5.衝擊反應分析受限於開發中國家股市資料較少及國家信用分數型態，而未有一致而明顯的結論。第一章、 緒論••••••••••••••••••••••••1第一節 研究背景與動機••••••••••••••••••••1第二節 研究目的•••••••••••••••••••••••4第三節 研究限制•••••••••••••••••••••••4第四節 研究內容與研究架構••••••••••••••••••5第二章、 文獻探討••••••••••••••••••••••7第一節 股票波動度的相關文獻•••••••••••••••••7第二節 國家風險的相關文獻••••••••••••••••••8第三節 干預分析的相關文獻••••••••••••••••••10第四節 衝擊反應分析的相關文獻••••••••••••••••12第三章、 資料來源與說明•••••••••••••••••••13第一節 太平洋盆地國家的股市資料來源與類型••••••••••13第二節 敘述統計•••••••••••••••••••••••15第三節 使用Institutional Investor的國家信用評等指標為解釋變數之因•22第四節 國家信用風險評比決定因子與過程••••••••••••24第五節 國家風險指標的有效性•••••••••••••••••25第四章、 實證結果••••••••••••••••••••••26第一節 理論架構•••••••••••••••••••••••26第二節 檢驗各國股價報酬的時間序列型態••••••••••••29第三節 變異數自身相關檢定(ARCH、GARCH檢定)••••••••38第四節 波動度解釋力檢定•••••••••••••••••••45第五節 國家信用評等解釋力檢定••••••••••••••••48第六節 衝擊反應分析•••••••••••••••••••••59第五章、 結論與後續研究建議•••••••••••••••••74第一節 結論•••••••••••••••••••••••••74第二節 後續研究建議•••••••••••••••••••••76參考文獻•••••••••••••••••••••••••••77一、 中文部份••••••••••••••••••••••••77二、 英文部份••••••••••••••••••••••••77附錄(外國專業投資機構直接投資國內狀況分析表) •••••••••80For the recent years, the global financial environment has been changing rapidly, which reminds qualified foreign institutional investors of more caution. This survey focuses on the relationship between stock returns, volatility and country credit rating changes among countries in the Asia-Pacific Basin. This research further divides the 12 sample countries into two categories, developed markets and emerging ones, and finds out the differences between both groups. The empirical methods used here are intervention analysis and impulse response analysis. The empirical results are as follows:1. The stock return and its volatility do not have statistically significant relation in both developed markets and emerging ones, which coincides with the conclusion by Baillie and Degennaro(1990).2. The impact of changes in country credit level on stock returns will work within one month; that is to say, changes in country credit level this month will affect stock returns of the current month.3. Country credit change has no impact on stock returns of the developed markets.4. Changes in country credit levels of the emerging markets have apparent influence on their stock returns but no identical signs. This may result from the common barriers existed in the emerging markets for foreign investors.5. The impulse response analysis doesn't have an apparent and agreeable result owing to the constraint of rare data

Isolation and structure of the sex-pheromone of the moth, Nudaurelia cytherea cytherea

The sex-pheromone of Nudaurelia cytherea cytherea has been isolated from the terminal segments of the female moth by solvent extraction, steam distillation, and column and gas-liquid chromatography. The structure was determined by infrared, nuclear magnetic resonance, and mass spectrometry as cis-dec-5-en-1-yl 3-methylbutanoate (isovalerate). The synthetic ester showed activity in field tests. © 1973.Articl

Survey of suspended particulate and selected elements in Kylepark, Uddingston, atmosphere

Available from British Library Document Supply Centre- DSC:7628.85(WSL-LR--620(PA)) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo