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Evaluation of mixed mode-Ⅰ/Ⅱ criteria for fatigue crack propagation using experiments and modeling

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Chinese Journal of Aeronautics 2018年第7期31卷 1525-1534页

作者： Oguzhan DEmIR Ali O.AYhAN Sedat IRIC hüseyin LEKESIZ Department of mechanical Engineering Sakarya University Department of mechanical Engineering Bilecik S?eyh Edebali University Department of mechanical Engineering Bursa Technical University

In this study, in-plane mixed mode-Ⅰ/Ⅱ fatigue crack growth simulations and experiments are performed for the Al 7075-T651 aluminum alloy which is widely used in the aerospace industry. Tests are carried out under different mode mixity ratios to evaluate the applicability of a fracture criterion developed in a previous study to mixed mode-Ⅰ/Ⅱ fatigue crack growth *** obtained from the analyses and experiments are compared with existing and developed criteria in terms of crack growth lives. Compact Tension Shear（CTS） specimens, which enable mixed mode loading with loading devices under different loading angles, are used in the simulations and experiments. In an effort to model and simulate the actual conditions in the experiments, crack surfaces of fractured specimens are scanned, crack paths are modeled exactly, and contacts are defined between the contact surfaces of a specimen and the loading device for each crack propagation step in the analyses. having computed the mixed mode stress intensity factors from the numerical analyses, propagation life cycles are predicted by existing and the developed mixed mode-Ⅰ/Ⅱ criteria and then compared with experimental results.

关键词： Crack propagation Fatigue crack growth simulation Fatigue crack growth test Fracture mechanics mixed mode-Ⅰ/Ⅱ

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Algebra Colloquium 2020年第2期27卷 193-198页

作者： S.m.Robati Department of mathematics Faculty of Science Imam Khomeini International UniversityQazvinIran

Let G be a group,and let →/ΓC(G) be a digraph whose vertices are the nontrivial conjugacy classes of G and there is an arc from a vertex C to a vertex C' if and only if C≠C' and(C)■(C').In this paper,we characteri... 详细信息

关键词： conjugacy classes posets graphs finite groups

Is Li-ESWT effective in diabetic patients with severe erectile dysfunction?

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Asian Journal of Andrology 2022年第5期24卷 521-524页

作者： müslüm Ergün Osman Akyüz Department of Urology School of MedicineAtlas UniversityIstanbul 34200Turkey

Noninvasive low-intensity extracorporeal shockwave treatment(Li-ESWT)has been widely used to treat erection *** is no clear information regarding either the selection of patients for the treatment or the treatment *** this study,we aimed to investigate the efficacy of extracorporeal shockwave therapy in diabetic patients with severe erectile dysfunction(International Index of Erectile Function-5[IIEF-5]scores of 5 to 7).Sixty-three diabetes mellitus patients with erectile dysfunction having IIEF-5 scores of 5 to 7 and not showing a recovery of potency despite phosphodiesterase type 5 inhibitor therapy for the past 6 months were included in the *** patients were evaluated based on their IIEF-5 scores and Erection hardness Scale *** IIEF-5 score(mean±standard deviation[s.d.])increased from 5.29±1.67 to 5.56±1.85,with a difference of 0.27±0.18(P>0.05).The Erection hardness Scale scores(mean±s.d.),on the other hand,increased from 1.46±0.50 to 1.48±0.50,with a difference of 0.02±0(P>0.05).In conclusion,the response to phosphodiesterase type 5 inhibitors did not change after extracorporeal shockwave treatment in diabetes mellitus patients with severe erectile dysfunction(IIEF-5 scores of 5 to 7).

关键词： diabetes mellitus International Index of Erectile Function-5 score low-intensity extracorporeal shockwave treatment severe erectile dysfunction

Ternary supramolecular quantum-dot network flocculation for selective lectin detection

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Nano Research 2016年第7期9卷 1904-1912页

作者： maria Oikonomou Junyou Wang Rui Rijo Carvalho Aldrik h. Velders Laboratory of BioNanoTechnology WageningenUR Dreijenplein 6 6703 HB Wageningen the Netherlands micronit microfluidics B.V. Colosseum 15 7521 PV Enschede the Netherlands Interventional molecular Imaging Laboratory Department of Radiology Leiden University Medical Center 2333 ZA Leiden the Netherlands

We present a versatile, tuneable, and selective nanoparficle-based lectin biosensor, based on flocculation of ternary supramolecular nanoparticle networks （NPN）, formed through the sequential binding of three building blocks. The three building blocks are ^-cyclodextrin-capped CdTe quantum dots, tetraethylene glycol-tethered mannose-adamantane cross-linkers （ADTEGman）, and the tetravalent lectin Concanavalin A （ConA）. The working principle of this selective sensor lies in the dual orthogonal molecular interactions of the linker, uniting adamantane-^-cyclodextrin and mannose-lectin interaction motifs, respectively. Only when the lectin is present, sequential binding takes place, leading to in situ self-organization of the sensor through the formation of ternary supramolecular networks. monitoring the loss of fluorescence signal of the quantum dots in solution, caused by controlled network formation and consecutive flocculation and sedimentation, leads to selective, qualitative, and quantitative lectin detection. Fluorescent sedimented networks can be observed by the naked eye or under UV illumination for a lectin concentration of up to 10 8 m. Quantitative detection is possible at 100 min with a lower detection limit of approximately 5 × 10 ^-8 m.

关键词： supramolecular cyclodextrin quantum dot sensor lectin flocculation

Biorefinery of Rice husk to Obtain Functionalized Bioactive Compounds

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Journal of Renewable materials 2019年第4期7卷 313-324页

作者： m.Lopretti N.Lecot A.Rodriguez G.Lluberas F.Orozco L.Bolaños G.montes De Oca h.Cerecetto J.Vega-Baudrit Laboratorio de Técnicas Nucleares Aplicadas a Bioquímica y Biotecnología Centro de Investigaciones Nucleares-Facultad de CienciasMataojo 2055Montevideo CP 11400Uruguay Área de Radiofarmacia Centro de Investigaciones Nucleares-Facultad de CienciasMataojo 2055Montevideo CP 11400Uruguay Química Bioanalítica Instituto Polo Tecnológico de Pando-Facultad de QuímicaUdelaRBy Pass de Pando y Ruta 8Pando-Canelones CP 91000Uruguay Laboratorio de Nacional de Nanotecnología-CeNAT-CONARE Costa Rica 1174-1200San JoséCP 10109Costa Rica Laboratorio de Polímeros POLIUNA-Escuela de Química Universidad NacionalHerediaSan JoséCP 86-3000Costa Rica

The biomass industrialization valorisation of grains and cereals is considered an opportunity for the countries where agro-industrial activity is one of its main economic activities,rendering new higher-value products with a concomitant solution to waste accumulation *** that end,in this work we describe and characterise bioactive compounds generation from rice husk by semisolid fermentation,obtained from 500 g of the material at room temperature and 60%humidity with mixed cultures of Phanerochaete chrysosporium and Gloeophyllum *** extract was evaluated in different situations:murine mammary tumour cells(4T1),normal cells(NIh 3T3)and in Lactobacillus acidophilus,and Trichoderma *** results exhibited that the extract inhibited 4T1 cells at concentrations higher than 20μg/mL,but did not inhibit normal cells,and displayed germicide activity after 3 days *** propose that these functionalized compounds have a potential application in industry/agriculture/medicine obtained from rice husk waste.

关键词： Biorefinery rice husk bioactive compounds valorisation of biomass veratryl alcohol

A novel process for sorting fine-sized sulphide minerals by biocoagulation

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中国有色金属学会会刊：英文版 2008年第6期18卷 1473-1479页

作者： h. Z. KUYUmCU J. PINKA T. BIELIG Department of mechanical Process Engineering and Solids Processing Technical University of Berlin Sekr. BH 11 Strasse des 17. Juni 135 10623 Berlin Germany

基于一个过程设计想法，在柏林的技术大学的调查证实微生物的 biocoagulation 和稳固的粒子将是一个新方法产生对排序合适的更粗糙的粒子。微生物的选择 biocoagulation 的过程，分别地例如酵母喜欢 Saccharomyces cerevisiae 和 Yarrow... 详细信息

基于一个过程设计想法，在柏林的技术大学的调查证实微生物的 biocoagulation 和稳固的粒子将是一个新方法产生对排序合适的更粗糙的粒子。微生物的选择 biocoagulation 的过程，分别地例如酵母喜欢 Saccharomyces cerevisiae 和 Yarrowia lipolytica，并且例如象方铅矿和闪锌矿一样的矿物质，微分散固体作为一个新奇排序过程的一个基础被分析了。因此，特别微生物的房间表面的特征例如静电的费用和细胞外的聚合物质的作文，以及他们对选择 biocoagulation 的影响被学习。在 10 m 下面的微生物和硫醚粒子有效地凝结的试验性的调查表演。而且，筹款对有选择地形成的 biocoagulates 的分离合适。与设计的列筹款，令人满意的恢复率被到达。

关键词：硫矿拣选生物凝固微生物

microstructural Characterization of the Shear Bands in Fe-Cr-Ni Single Crystal by EBSD

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Journal of materials Science & Technology 2008年第6期24卷 819-828页

作者： huajie YANG J.h.Zhang Yongbo XU marc Andre＇ meyers Shenyang National Laboratoryof materials Sciences Institute of Metal Researchl Chinese Academy of Sciences Shenyang 110016 China University of California San Diego La Jolla CA92093-0411 USA

An investigation has been made into the microstructural characterization of the shear bands generated under high-strain rate （≈10^4 s^-1） deformation in Fe-15%Cr-15%Ni single crystal by EBSD-SEm （electron backscatter diffraction-scanning electron microscopy）, TEm （transmission electron in microscopy） and hREm （high- resolution electron microscopy）. The results reveal that the propagation of the shear band exhibits an asymmetrical behavior arising from inhomogenous distribution in plasticity in the bands because of different resistance to the collapse in different crystallographic directions; The γ-ε-α′phase transformations may take place inside and outside the bands, and these martensitic phases currently nucleate at intersections either between the twins and deformation bands or between the twins and ε-sheet. Investigation by EBSD shows that recrystallization can occur in the bands with a grain size of an average of 0.2μm in diameter. These nano-grains are proposed to attribute to the results of either dynamic or static recrystallization, which can be described by the rotational recrystallization mechanism. Calculation and analysis indicate that the strain rate inside the shear band can reach 2.50×10^6 s^-1, which is higher, by two or three orders of magnitude, than that exerted dynamically on the specimen tested.

关键词： high-strain rate deformation Adiabatic shear band Electron backscatter diffraction (EBSD) Recrystallization Fe-Cr-Ni single crystal

Implementation aspects of a phase-field approach for brittle fracture

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Frontiers of Structural and Civil Engineering 2019年第2期13卷 417-428页

作者： G.D.hUYNh X.,ZhUANG h.NGUYEN-XUAN Institute of Continuum mechanics Leibniz-Universitat Hannover30167 HannoverGermany Center for Interdisciplinary Research in Technology Ho Chi Minh CityUniversity of Technology (HUTEH)Ho Chi Minh City Vietnam

This paper provides a comprehensive overview of a phase-field model of fracture in solid mechanics setting. We start reviewing the potential energy governing the whole process of fracture including crack initiation, branching or merging. Then, a discretization of system of equation is derived, in which the key aspect is that for the correctness of fracture phenomena, a split into tensile and compressive terms of the strain energy is performed, which allows crack to occur in tension, not in compression. For numerical analysis, standard finite element shape functions are used for both primary fields including displacements and phase field. A staggered scheme which solves the two fields of the problem separately is utilized for solution step and illustrated with a segment of Python code.

关键词： phase-field modeling FEm staggered scheme fracture

In vivo antiplasmodial and in vitro antioxidant property of stem bark extracts of haematostaphis barteri

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Asian Pacific Journal of Tropical Biomedicine 2015年第6期5卷 444-448页

作者： johnson Nyarko Boampong Akua Afryie Karikari Elvis Ofori Ameyaw Department of Biomedical and Forensic Sciences University of Cape Coast

Objective: To evaluate the antimalarial and antioxidant properties of stem bark extracts of haematostaphis barteri(h. barteri).methods: The prophylactic activity of the plant was performed by dosing mice with sulfadoxine-pyrimethamine(1.2 mg/kg), aqueous extract(30, 100, 300 mg/kg) and dichloromethane/methanol(D/m)(30, 100, 300 mg/kg) extracts of h. barteri for 3 days. On the 4th day, the mice were inoculated with Plasmodium berghei. The parasite density was estimated for each mouse 72 h post-parasite inoculation. The curative activity of the plant was also performed by inoculating mice with Plasmodium berghei. Three days later, they were treated with artemether-lumefantrine(4 mg/kg), aqueous and D/m extracts of h. barteri stem bark for 5 days. The in vitro antioxidant property of the aqueous extract was determined by using the reducing power, nitric oxide and total antioxidant capacity assays. Results: The aqueous extract exerted significant(P hylactic antimalarial activities. The D/m extract exhibited significant curative(P hylactic antiplasmodial ef ect. The aqueous extract exhibited in vitro antioxidant property with IC50’s of(0.930 ± 0.021) mg/mL,(0.800 ± 0.001) mg/mL and(0.22 ± 0.05) mg/mL in the total antioxidant capacity, reducing power and nitric oxide assays. histological assessment of the liver of aqueous and D/m treated animals did not reveal any sign of ***: h. barteri is not toxic which exerted significant curative antiplasmodial ef ects but the prophylactic property was however fraction dependent. The mechanism of the antiplasmodial activity of h. barteri may partly be mediated by its antioxidant property.

关键词： malaria Parasitemia haematostaphis barteri Antioxidants Phytochemicals