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Critical interfaces in body armour systems

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Defence Technology（防务技术） 2021年第6期17卷 1887-1894页

作者： Ian g.Crouch Ulverston Armour Solutions UlverstonLA127BJCumbriaUK

The ballistic performance,and behaviour,of an armour system is governed by two major sets of variables,geometrical and *** these,the consistency of performance,especially against small arms ammunition,will depend upon the consistency of the properties of the constituent *** a body armour system for example,fibre diameter,areal density of woven fabric,and bulk density of ceramic are examples of critical parameters and monitoring such parameters will form the backbone of associated quality control *** is often overlooked,because it can fall into the User’s domain,are the interfaces that exist between the various products;the carrier,the Soft Armour Insert(SAI),and the one or two hard armour plates(HAP1 and HAP2).This is especially true if the various products are sourced from different suppliers.

关键词： Interfaces Body armour Body armor Ceramic armour UHMWPE Aramids Ballistic fibres Fabrics Interfacial materials Hard armour plates Soft vests

Trajectory predictions of new lift separation sabots

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Defence Technology（防务技术） 2021年第4期17卷 1361-1373页

作者： Sreelal Mohanan Rajesh g Department of Aerospace Engineering Indian Institute of Technology MadrasChennaiTamilnadu600036India

This paper presents a modified analytical model to evaluate the trajectories of various lift separation sabot *** aerodynamic forces acting on the sabot surfaces during a supersonic flight are modeled in the present analytical model by incorporating the pressures on the windward side of the sabot due to the detached/attached shock and its reflections and then integrated using the 3-DoF dynamical *** trajectory and the aerodynamic coefficients were obtained for these configurations at a projectile Mach number of *** sabot configurations,which include two new designs,are compared with each other and with the conventional free flight trajectory data of the conventional *** mechanical interaction between the sabot and projectile is also addressed in the present *** comparison shows that the new designs with the aerodynamic surfaces close to the center of gravity,lift-off from the projectile with minimal mechanical interaction compared to a conventional sabot.

关键词： Lift separation Sabot Trajectory Shock reflection

Bianchi type I in f(T) gravitational theories

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Chinese Physics B 2016年第5期25卷 58-64页

作者： M I Wanas g g L Nashed O A Ibrahim Astronomy Department Faculty of Science Cairo University Cairo Egypt Centre for Theoretical Physics The British University in Egypt El-Sherouk City Egypt Mathematics Department Faculty of Science Ain Shams University Cairo Egypt Egyptian Relativity group (ERg) Giza Egypt

A tetrad field that is homogeneous and anisotropic which contains two unknown functions A（t） and B（t） of cosmic time is applied to the field equations of f（T）, where T is the torsion scalar, T = T~μ_（νρ）S_μ^（νρ）. We calculate the equation of continuity and rewrite it as a product of two brackets, the first is a function of f（T） and the second is a function of the two unknowns A（t） and B（t）. We use two different relations between the two unknown functions A（t） and B（t） in the second bracket to solve it. Both of these relations give constant scalar torsion and solutions coincide with the de Sitter one. So,another assumption related to the contents of the matter fields is postulated. This assumption enables us to drive a solution with a non-constant value of the scalar torsion and a form of f（T） which represents ΛCDM.

关键词： f(T) gravitational theory Bianchi type I special solutions

Investigation on 3Dt wake flow structures of swimming bionic fish

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Acta Mechanica Sinica 2012年第5期28卷 1494-1508页

作者： g.-X.Shen g.-K.Tan g.-J.Lai Fluid Mechanics Institute Beihang University

A bionic experimental platform was designed for the purpose of investigating time accurate three-dimensional flow field, using digital particle image velocimetry （DSPIV）. The wake behind the flapping trail of a robotic fish model was studied at high spatial resolution. The study was performed in a water channel. A robot fish model was designed and built. The model was fixed onto a rigid support frame- work using a cable-supporting method, with twelve stretched wires. The entire tail of the model can perform prescribed motions in two degrees of freedom, mainly in carangiform mode, by driving its afterbody and lunate caudal fin respectively. The DSPIV system was set up to operate in a trans- lational manner, measuring velocity field in a series of parallel slices. Phase locked measurements were repeated for a number of runs, allowing reconstruction of phase average flow field. Vortex structures with phase history of the wake were obtained. The study reveals some new and complex three-dimensional flow structures in the wake of the fish, including ＂reverse hairpin vortex＂ and ＂reverse Karman S-H vortex rings＂, allowing insight into physics of this complex flow.

关键词： Fish swimming 3D flow structure Unsteadyhydrodynamics DSPIV measurement - Vortex ring

Assessing fire severity in Turkey's forest ecosystems using spectral indices from satellite images

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Journal of Forestry Research 2023年第6期34卷 1747-1761页

作者： Coşkun Okan güney Ahmet Mert Serkan gülsoy Department of Forest Fires Aegean Forestry Research Institute35430 IzmirTurkey Department of Wildlife Ecology and Management Faculty of ForestryIsparta University of Applied Science32260 IspartaTurkey Department of Soil Science and Ecology Faculty of ForestryIsparta University of Applied Science32260 IspartaTurkey

Fire severity classifications determine fire damage and regeneration potential in post-fire areas for effective implementation of restoration *** fire damage varies according to vegetation and fire characteristics,regional assessment of fire severity is *** objectives of this study were:(1)to test the performance of different satellite imagery and spectral indices,and two field—measured severity indices,CBI(Composite Burn Index)and geoCBI(geometrically structured Composite Burn Index)to assess fire severity;(2)to calculate classification thresholds for spectral indices that performed best in the study areas;and(3)to generate fire severity maps that could be used to determine the ecological impact of forest *** large fires in Pinus brutia(Turkish pine)and Pinus nigra *** ***(Anatolian black pine)—dominated forests during 2020 and 2021 were selected as study *** results show that geoCBI provided more reliable estimates of field—measured fire severity than *** Sentinel-2 and Landsat-8/OLI images performed similarly well,MODIS performed *** severity classification thresholds were determined for Sentinel-2 based RdNBR,dNBR,dSAVI,dNDVI,and dNDMI and Landsat-8/OLI based dNBR,dNDVI,and *** several spectral indices,the highest accuracy for fire severity classification was found for Sentinel-2 based RdNBR(72.1%)and Landsat-8/OLI based dNBR(69.2%).The results can be used to assess and map fire severity in forest ecosystems similar to those in this study.

关键词： Remote sensing Forest fire Fire severity Spectral indices Composite burn index

Suppression of Self-Discharge in Aqueous Supercapacitor Devices Incorporating Highly Polar Nanofiber Separators

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Energy & Environmental Materials 2023年第3期6卷 74-86页

作者： Wesley g.Buxton Simon g.King Vlad Stolojan Advanced Technology Institute University of SurreyGuildford SurreyGU27XHUK

One of the major problems limiting the applications of electric double-layer(EDLC)supercapacitor devices is their inability to maintain their cell voltage over a significant ***-discharge is a spontaneous decay in charged energy,often resulting in fully depleted devices in a matter of ***,a new method for suppressing this self-discharge phenomenon is proposed by using directionally polarized piezoelectric electrospun nanofiber films as separator *** engineering of polyvinylidene fluoride(PVDF)nanofiber films containing a small concentration of sodium dodecyl sulfate(SDS)results in a high proportion of polarβphases,reaching 380.5%of the total *** polarity into the separator material provides a reverse-diode mechanism in the device,such that it drops from an initial voltage of 1.6 down to 1 V after 10 h,as opposed to 0.3 V with a nonpolarized,commercial separator ***,the energy retained for the polarized separator is 37%and 4%for the nonpolarized separator,making supercapacitors a more attractive solution for long-term energy storage.

关键词： piezoelectric polar nanofibers PVDF separators self-discharge supercapacitors

Effects of precommercial thinning intensity on growth of Fagus orientalis Lipsky stands over 6 years

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Journal of Forestry Research 2022年第3期33卷 937-947页

作者： Deniz güney Fahrettin Atar İbrahim Turna Alkan günlü Department of Forest Engineering Faculty of ForestryKaradeniz Technical UniversityTrabzon61080Turkey Department of Forest Engineering Faculty of ForestryÇankırıKaratekin UniversityÇankırıTurkey

Determining the most suitable intensities for precommercial thinning (PCT) in oriental beech (Fagus orientalis) stands, which cover substantial areas in Turkey and have a high economic and ecological value, is essential to provide higher economic return and obtain well-formed stems. The effects of various rates of PCT interventions on the growth characteristics of natural stands, located in the northern part of Turkey, were explored to determine appropriate thinning rates;24 experimental PCT plots (4 PCT rates × 3 replications × 2 sites) were established in young thicket-stage stands and four precommercial thinning rates such as light (1 – 1.5 m spacing), moderate (1.5−2.0 m spacing) and heavy (2.5–3.0 m spacing) thinning, including a control plot (i.e., untreated), were applied. At the end of the 2007 and 2010 growing seasons, the diameter and height of the trees were measured and growth analyzed based on the 3-year and 6-year incremental growth. PCT levels were found to have significant (P ght, total basal area and total volume increment at the end of each period. The mean diameter and height increment proportionally increased with increasing PCT intensity in the third and the sixth year. In both sites, the moderate PCT provided the greatest total basal area and total volume increment. The early results indicate that the moderate PCT (1.5–2 m spacing) boosted stand development over time.

关键词： Tending operation Stand development Precommercial thinning Thicket stage

Embedded Atom Method-Based geometry Optimization Aspects of Body-Centered Cubic Metals

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Chinese Physics Letters 2013年第5期30卷 112-115页

作者： M.güler E.güler Department of Physics Hitit University19030 CorumTurkey

We present embedded atom method-based geometry optimization calculations for Fe, Cr, Mo, Nb, Ta, V and W body-centered cubic metals with Finnis–Sinclair potentials. After the optimization, we determine their typical elastic constants, bulk modulus, shear modulus, Young's modulus, Poisson's ratios, elastic wave velocities and cohesive energies. Additionally, we perform a benchmark between the experiments and the available density functional theory results. In general, our results show a good consistency with previous findings on the elastic and cohesive energy properties of the considered metals.

关键词： modulus optimization cubic

Role of sex hormones in the modulation of cholangiocyte function

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World Journal of gastrointestinal Pathophysiology 2010年第2期1卷 50-62页

作者： Romina mancinelli Paolo Onori Sharon DeMorrow Heather Francis Shannon glaser Antonio Franchitto guido Carpino gianfranco Alpini Eugenio gaudio Department of Human Anatomy University of Rome "La Sapienza" Department of Experimental Medicine University of L'Aquila Scott and White Digestive Disease Research Center Texas A&M Health Science CenterCollege of Medicine Department of Health Science University of Rome "Foro Italico"Rome 00135Italy Research Central Texas Veterans Health Care System

Over the last years,cholangiocytes,the cells that line the biliary tree,have been considered an important object of study for their biological properties which involves bile formation,proliferation,injury repair,fibrosis and *** proliferation occurs in all pathologic conditions of liver injury where it is associated with inflammation and *** these processes,biliary cells start to secrete different cytokines,growth factors,neuropeptides and hormones which represent potential mechanisms for cross talk with other liver *** studies suggest that hormones,and in particular,sex hormones,play a fundamental role in the modulation of the growth of this compartment in the injured liver which functionally conditions the progression of liver *** the mechanisms of action and the intracellular pathways of these compounds on cholangiocyte pathophysiology will provide new potential strategies for the management of chronic liver *** purpose of this review is to summarize the recent findings on the role of sex hormones in cholangiocyte proliferation and biology.

关键词： Biliary epithelium Sex hormones Cholestatic diseases