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Marble epistyles under shear: an experimental study of the role of “Relieving Space”

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Frontiers of Structural and Civil engineering 2019年第4期13卷 767-786页

作者： e. D. PASiOU i. STAVRAKAS D. TRiANTiS S. K. KOURKOULiS Department of Mechanics Laboratory of Testing and Materials National Technical University of Athens Athens 15773 Greece Department of electronics Laboratory of Electrical Characterization of Materials and Electronic Devices Technological Edu-cational Institution of Athens Athens 12210 Greece

The mechanical response of mutually interconnected epistyles is studied experimentally. The specimens are made of two marble blocks connected to each other with an “i”-shaped titanium connector placed in grooves sculptured on the blocks and covered with cementitious material. The specific way of connecting epistyles simulates the one used by scientists restoring the ancient “connections” of the epistyles of the Parthenon Temple. This “connection”, although designed to sustain mainly tensile loading, undertakes, also, shear load, in case of excitations imposing to the epistyles displacements normal to the connector’s axis. Attention is focused to enlighten the role of a novel design technique aiming to relieve the stress field around the connector. According to this technique, part of the connector’s web is left uncovered, forming the so-called “Relieving Space”, assisting the unconstrained deformation of the connector. Both traditional and innovative sensing techniques were employed in an effort to obtain data from the interior of the three-material-complex (marble-cementitious material-titanium). Analysis of the data indicated that the “Relieving Space” reduces the overall stiffness of the system, protecting marble in case of over-loading. Moreover, it was concluded that the innovative techniques employed provide pre-failure indicators well in advance of the catastrophic failure of the specimens.

关键词： monuments of cultural he.i.a.e marble epistyles pressure stimulated currents acoustic emission digital image correlation

Many-body interatomic Potentials for Computer Simulation of Physical Processes in Metals and Alloys

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Journal of Materials Science & Technology 1998年第5期14卷 429-433页

作者： Kuznetsov, V.M. Rudenskii, G.e. Kadyrov, R.i. Kaminskii, P. institute of Strength Physics and Material Science Russian Academy of Sciences Siberian Branch 634048 Tomsk Academicheskii av. 2/1 Russian Federation

A model of binding forces in metals and alloys, based on the density functional theory and accounted effects of the many-body interactions, was proposed. The developed method can be easily applied for study of metals and alloys by the molecular dynamics simulation. The potentials of interatomic interactions have been found by the proposed method and applied for calculations of equation of state, elastic moduli and phonon dispersion in metals Ni, Al, and alloys NiAl, Ni//3Al. Results of the calculations are in good agreement with known experimental data both for pure metals and alloys. (edited author abstract) 16 Refs.

关键词： Nickel

Bistability in Coupled Oscillators exhibiting Synchronized Dynamics

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Communications in Theore.i.a. Physics 2010年第5期53卷 815-824页

作者： O.i.Olusola U.e.Vincent A.N.Njah J.A.Olowofela Department of Physics University of Agriculture Department of Physics Lancaster University institut fur Theoretische Physik Technische Universitt Clausthal Department of Physics Olabisi Onabanjo University

We report some new results associated with the synchronization behavior of two coupled double-well Duffing oscillators （DDOs）. Some sufficient algebraic criteria for global chaos synchronization of the drive and response DDOs via linear state error feedback control are obtained by means of Lyapunov stability theory. The synchronization is achieved through a bistable state in which a periodic attractor co-exists with a chaotic attractor. Using the linear perturbation analysis, the prevalence of attractors in parameter space and the associated bifurcations are examined. Subcritical and supercritical Hopf bifurcations and abundance of Arnold tongues -- a signature of mode locking phenomenon are found.

关键词： chaos synchronization Duffing oscillator bistability Lyapunov stability theory

THe WAVe eQUATiON APPROACH TO THe TWO-DiMeNSiONAL iNVeRSe PROBLeM FOR A GeNeRAL BOUNDeD DOMAiN WiTH PieCeWiSe SMOOTH MiXeD BOUNDARY CONDiTiONS

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Acta Mathematica Scientia 2001年第2期21卷 171-181页

作者： e.M.e.Zayed, i.H.Abdel-Halim Mathematics Department, Faculty of Science, Zagazig University, Zagazig, egypt e-mail: emezayed@*** & ismhalim@*** Mathematics Department Faculty of Science Zagazig University Zagazig Egypt

The spectral distribution exp( ), where {} are the eigenvalues of the negative Laplacian -△=- in the (x^1,x^2)-plane, is studied for a variety of domains, where -∞< t <∞ and i=(1/2)(-1) . The dependence of (t)on t... 详细信息

The spectral distribution exp( ), where {} are the eigenvalues of the negative Laplacian -△=- in the (x^1,x^2)-plane, is studied for a variety of domains, where -∞i=(1/2)(-1) . The dependence of (t)on the connectivity of a domain and the boundary conditions are analyzed. Particular attention is given to a general bounded domain Ω in R^2 with a smooth boundary Ω, where a finite number of piecewise smooth Dirichlet, Neumann and Robin boundary conditions on the piecewise smooth parts Γj(j = 1,……,n) of Ω are considered such that Some geometrical properties of Ω(e.g., the area of Ω, the total lengths of the boundary, the curvature of its boundary, etc.) are determined, from the asymptotic expansions of (t) for |t| → 0.

关键词： inverse problem spectral distribution wave equation eigenvalues

Feeding a Saccharomyces cerevisiae fermentation product improves udder health and immune response to a Streptococcus uberis mastitis challenge in mid-lactation dairy cows

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Journal of Animal Science and Biotechnology 2021年第4期12卷 1351-1369页

作者： M.Vailati-Riboni D.N.Coleman V.Lopreiato A.Alharthi R.e.Bucktrout e.Abdel-Hamied i.Martinez-Cortes Y.Liang e.Trevisi i.Yoon J.J.Loor Department of Animal Sciences and Division of Nutritional Sciences University of IllinoisUrbanaUrbanaIL 61801USA Department of Animal Sciences Food and Nutrition(DIANA)UniversitàCattolica del Sacro Cuore29122 PiacenzaItaly Department of Animal Production College of Food and Agriculture SciencesKing Saud UniversityRiyadh 11451Saudi Arabia Department of Animal Medicine Faculty of Veterinary MedicineBeni-Suef UniversityBeni-Suef 62511Egypt Agricultural and Animal Production Department UAM-Xochimilco04960 Mexico CityMexico Diamond V Cedar RapidsIAUSA

Background:We aimed to characterize the protective effects and the molecular mechanisms of action of a Saccharomyces cerevisiae fermentation product(NTK)in response to a mastitis *** mid-lactation multiparous Holstein cows(n=9/group)were fed the control diet(CON)or CON supplemented with 19 g/d NTK for 45 d(phase 1,P1)and then infected in the right rear quarter with 2500 CFU of Streptococcus uberis(phase 2,P2).After 36-h,mammary gland and liver biopsies were collected and antibiotic treatment started until the end of P2(9 d post challenge).Cows were then followed until day 75(phase 3,P3).Milk yield(MY)and dry matter intake(DMi)were recorded *** samples for somatic cell score were collected,and rectal and udder temperature,heart and respiration rate were recorded during the challenge period(P2)together with blood samples for metabolite and immune function *** were analyzed by phase using the PROC MiXeD procedure in *** were used for transcriptomic analysis via RNA-sequencing,followed by pathway ***:DMi and MY were not affected by diet in P1,but an interaction with time was recorded in P2 indicating a better recovery from the challenge in NTK compared with *** reduced rectal temperature,somatic cell score,and temperature of the infected quarter during the *** data supported these findings,as NTK supplementation upregulated mammary genes related to immune cell antibacterial function(e.g.,CATHL4,NOS2),epithelial tissue protection(***17C),and anti-inflammatory activity(e.g.,ATF3,BAG3,ieR3,G-CSF,GRO1,ZFAND2A).Pathway analysis indicated upregulation of tumor necrosis factorα,heat shock protein response,and p21 related pathways in the response to mastitis in NTK *** pathways for detoxification and cytoprotection functions along with the tight junction pathway were also upregulated in NTK-fed ***:Overall,results highlighted molecular networks involved in the protective effect

关键词： Dairy cow Mastitis RNA-sequencing Saccharomyces cerevisiae fermentation product Udder health

influence of processing route on microstructure and wear resistance of fly ash reinforced AZ31 magnesium matrix composites

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Journal of Magnesium and Alloys 2019年第1期7卷 155-165页

作者： i.Dinaharan S.C.Vettivel M.Balakrishnan e.T.Akinlabi Department of Mechanical engineering Science University of JohannesburgAuckland Park Kingsway CampusJohannesburg 2006 GautengSouth Africa Department of Mechanical engineering Chandigarh College of Engineering and TechnologyChandigarh 160019India Department of Mechanical engineering Nehru Institute of Engineering and TechnologyCoimbatore 641105 Tamil NaduIndia

Utilizing fly ash(FA)as reinforcement for magnesium matrix composites(MMCs)brings down the production cost and the land *** alloy AZ31 was reinforced with FA particles(10 vol.%)successfully by two different processing methods namely conventional stir casting and friction stir processing(FSP).The microstructural features were observed using optical microscope,scanning electron microscope and electron backscatter *** sliding wear behavior was tested using a pin-on-disc wear *** stir cast composite showed inhomogeneous particle dispersion and coarse grain *** of the FA particles decomposed and reacted with the matrix alloy to produce unde.i.a.le ***,FSP composite showed superior particle dispersion and fine,equiaxed grains by dynamic *** particles encountered disintegration but there was no interfacial *** composite demonstrated higher strengthening and wear resistance to that of stir cast *** morphology of the worn surface and the wear debris were studied in detail.

关键词： Magnesium matrix composite Stir casting Friction stir processing Fly ash Wear

Predatory pollinator deception： Does the orchid mantis resemble a model species？

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Current Zoology 2014年第1期60卷 90-103页

作者： J.C. O'HANLON G. i. HOLWeLL M.e. HeRBeRSTeiN Department of Biological Sciences Macquarie University North Ryde 2109 Australia School of Biological Sciences University of Auckland Auckland 1142 New Zealand

Cases of imperfect or non-model mimicry are common in plants and animals and challenge intuitive assumptions about the nature of directional selection on mimics. Many non-rewarding flower species do not mimic a particular species, but at- tract pollinators through ＇generalised food deception＇. Some predatory animals also attract pollinators by resembling flowers, perhaps the most well known, yet least well understood, is the orchid mantis Hymenopus coronatus. This praying mantis has been hypothesised to mimic a flower corolla and we have previously shown that it attracts and captures pollinating insects as prey. Predatory pollinator deception is relatively unstudied and whether this occurs through model mimicry or generalised food decep- tion in the orchid mantis is unknown. To test whether the orchid mantis mimics a specific model flower species we investigated similarities between its morphology and that of flowers in its natural habitat in peninsular Malaysia. Geometric morphometrics were used to compare the shape of mantis femoral lobes to flower petals. Physiological vision models were used to compare the colour of mantises and flowers from the perspective of bees, flies and birds. We did not find strong evidence for a specific model flower species for the orchid mantis. The mantis＇ colour and shape varied within the range of that exhibited by many flower pet- als rather than resembling one type in particular. We suggest that the orchid mantis resembles an average, or generalised flower-like stimulus. Thus predatory pollinator deception in the orchid mantis is likely to function as a form of generalised food deception, as opposed to model mimicry .

关键词： Mimicry Orchid mantis Hymenopus coronatus Generalised food deception Aggressive mimicry

TDS-eh graph analysis： a new water quality index and rural water supply implications of a river affected by mining in south-eastern Nigeria

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Frontiers of earth Science 2012年第1期6卷 66-74页

作者： i.C.eZeKWe A.O.AiSUBeOGUN G.N.CHiMA e.ODUBO Department of Geography and environmental Management Niger Delta UniversityWilberforce IslandPMB 071Yenegoa Nigeria Department of Geography and Planning Abia State UniversityPMB 2000UturuNigeria

The ivo River Basin of south-eastern Nigeria is a water scarce and mining region, which suffers from water scarcity. The influence of mining activities on the quality of the ivo River and its capacity for community water supply was investigated. Also the efficacy of TDS-eh graph in explaining water quality was presented. Results indicated that the TDS-eh graph highlights subtle che.i.a. relationships which control water quality and provide a simple but generic pollution index for rapid water quality assessment. it was also discovered that the ivo River could become an adequate alternative to groundwater as a source of rural water supply in the study area with an estimated average daily discharge of 6726000L and a rural population of less than 200000 persons. The ivo River meets the WHO drinking water standards in 20 physico- che.i.a. water quality parameters （pH, temperature, conductivity, turbidity, salinity, TDS, eh, alkalinity, chloride, nitrate, sulfate, phosphate, calcium, magnesium, iron, manganese, zinc, lead and cadmium） analyzed and can therefore （with little treatment） provide up to 133.4% of average community water demand and 83.8% of maximum community water demand. The. impact of mining on ivo River quality was found to have been moderated by the presence of carbonate rocks which may have enhanced the precipitation of heavy metals from the river.

关键词： TDS-eh graph water quality mining ruralwater supply ivo River Nigeria

investigation of the transformation of organic matter of carbonate deposits of the Semiluksky-Mendymsky horizon under hydrothermal conditions

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Petroleum 2024年第2期10卷 216-223页

作者： S.M.Petrov A.i.Lakhova e.G.Moiseeva A.G.Safiulina institute of Petroleum Chemistry and NanotechnologiesKazan National Research Technological UniversityKazan420015Russia institute of Geology and Oil and Gas Technologies Kazan Federal UniversityKazan420008Russia

The paper presents the results of studies on the transformation of the organic matter of siliceous-clayey carbonate rocks of the Semiluksko-Mendymsky horizon of the Romashkino oil field in a hydrothermal fluid for an hour(with a water-to-rock ratio of 33)at 340℃and 380℃and pressu res of 17 and 20 *** a result of hydrothermal treatment,at 340℃and 17 MPa,based on nitrogen porosimetry and electron microscopy data,transformations of rock-forming minerals in the rock are *** lead to an increase in the volume and average diameter of mesopores in it and the formation of micropores,as well,which improve its filtration *** the same time,the amount of kerogen in the composition of the organic matter decreases and the yield of the petroleum hydrocarbon extract increases,in which,according to the SARA analysis,the content of asphaltenes increases and the content of resins,aromatic and saturated hydrocarbons *** the composition of aroatic hydrocarbons,the proportion of a lkyltri methyl benzenes and dibenzothiophenes increases,phenanthrene homologues appear,and in the composition of saturated hydrocarbons,the amount of iso-structure alkanes decreases relative to the content of linear *** the temperature and pressure of the hydrothermal fluid to 380℃and 20 MPa increases the degree of kerogen conversion from 12.4%to 23.6%.At the same time,changes occurring in the component composition of petroleum hydrocarbon extracts remains similar to the experiments carried out at 340℃and 17 MPa;the content of naphthalenes decreases,the content of dibenzothiophenes increases and C_(11)-C_(17),C_(19)-C_(22)alkyltrimethylbenzenes *** to iR spectroscopy,with increasing temperature and pressure of the hydrothermal fluid the intensity of the absorption bands of the aromatic ring,aliphatic fragments,and oxygen-containing groups increases in resins;the structural-group composition of asphaltenes changes little:aromaticity and the content of conde

关键词： Carbonate deposits Organic matter Hydrothermal fluid Mobile hydrocarbons