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The effect of carbon nanotubes and polypropylene fibers on bond of reinforcing bars in strain resilient cementitious composites

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Frontiers of Structural and Civil Engineering 2016年第2期10卷 214-223页

作者： Souzana P. TASTANI Maria S. KONSTA-GDOUTOS, Stavroula j. PANTAZOPOULOU victor BALOPOULOS Department of Civil Engineering Democritus University oJ Thrace Vas. Sofias Street #12 Xanthi 67100 Greece

Stress transfer between reinforcing bars and concrete is engaged through rib translation relative to concrete, and comprises longitudinal bond stresses and radial pressure. The radial pressure is equilibrated by hoop tension undertaken by the concrete cover. Owing to concrete＇s poor tensile properties in terms of strength and deformability, the equilibrium is instantly released upon radial cracking of the cover along the anchorage with commensurate abrupt loss of the bond strength. Any improvement of the matrix tensile properties is expected to favorably affect bond in terms of strength, resilience to pullout slip, residual resistance and controlled *** aim of this paper is to investigate the local bond of steel bars developed in adverse tensile stress conditions in the concrete cover. In the tests, the matrix comprises a novel, strain resilient cementitious composite （SRCC） reinforced with polypropylene fibers （PP） with the synergistic action of carbon nano-tubes （CNT）. Local bond is developed over a short anchorage length occurring in the constant moment region of a four-point bending short beam. Parameters of investigation were the material structure （comprising a basic control mix, reinforced with CNTs and/or PP fibers） and the age of testing. Accompanying tests used to characterize the cementitious material were also conducted. The test results illustrate that all the benefits gained due to the synergy between PP fibers and CNTs in the matrix, namely the maintenance of the multi-cracking effect with time, the increased strength and deformability as well as the highly increased material toughness, were imparted in the recorded bond response. The local bond response curves thus obtained were marked by a resilient appearance exhibiting sustained strength up to large levels of controlled bar-slip; the elasto-plastic bond response envelope was a result of the confining synergistic effect of CNTs and the PP fibers, and it occurred even without bar yielding.

关键词： carbon nanotubes strain resilient cementitious composite polypropylene fibers tensile bending bond

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Molecular identification and population dynamics of two species of Pemphigus （Homoptera： Pemphidae） on cabbage

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Insect Science 2009年第2期16卷 115-124页

作者： Naiqi Chen Tong-Xian Liu Mamoudou Setamou j. victor French Eliezer S. Louzada Department of Entomology Texas AgriLife Research Texas A&M University System Weslaco Citrus Center Texas A&M University- Kingsville Citrus Center Weslaco TX 78596 USA

The poplar petiole gall aphid, Pemphiguspopulitransversus Riley, has been one of the maj.r pests on cruciferous vegetable in the Rio Grande Valley （LRGV） of Texas since the late 1940s. It normally migrates from poplar trees to cruciferous vegetables in the fall, and migrates back to the trees in early spring of the coming year. Some root-feeding aphids were found on cruciferous vegetables in late spring and early summer in 1998 and the following years. Those aphids have been identified as Pemphigus obesinymphae Moran. This discovery completely changed the current knowledge about the root-feeding aphids on cruciferous vegetables in the LRGV. Due to their small size, morphological and feeding similarities between P. populitransversus and P. obesinymphae, their identification and distinction are difficult. In this study, random amplification of polymorphic DNA （RAPD） and amplified fragment length polymorphism （AFLP） were used to distinguish these two species over a period of time when the two species occurred together, or separately, in cabbage fields. The two species occurred on cabbage at different times of the year, and overlapped from October to j.ne. From May to October, both species migrated to their primary hosts. The apterous aphids found on cabbage in winter contained mainly P. obesinymphae, whereas in early spring more apterous P. populitransversus were recovered. The root-feeding aphids would feed on cabbage plants as long as this host was available even during the hot, dry summer in the LRGV, although their populations were generally low. Both RAPD and AFLP techniques were efficient in discriminating the two species that showed obviously genetic variability. These molecular techniques confirmed the existence of the two aphid species in apterous samples collected from the soil in cabbage fields in the LRGV, and the results performed by RAPD were confirmed by AFLP. Furthermore, the results suggest that RAPD technique was a better choice despite its reproducib

关键词： AFLP cabbage identification RAPD root aphid

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Hepatic rupture secondary to HELLP syndrome: outcomes in three cases

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World j.urnal of Emergency Medicine 2024年第1期15卷 56-58页

作者： Salvador gomez-Carro Ruben R.Lozano-Salazar Kassandra Santos-Zaldívar victor Andres Villasuso-Alcocer Nina Méndez-Domínguez O'Horan General Hospital Merida 97000Mexico Highly Specialized Hospital of the Yucatan Peninsula Merida 97134Mexico National Institute of Perinatology.Mexico City 11000 Mexico

Hypertensive disorders of pregnancy,including chronic hypertension,gestational hypertension,and preeclampsia,are the most common complications in pregnant women,affecting approximately 15%of pregnancies.[1,2]Hemolysis,elevated liver enzymes,and low platelet count(HELLP syndrome)can occur in 0.2%-0.6%of all pregnancies,and 10%-15%of patients are diagnosed with preeclampsia.[3,4]Among its severe complications,liver hematoma is remarkable and may lead to liver *** identification of HELLP syndrome is crucial for proper therapeutic management and to avoid fatal outcomes[4,5]since when a hepatic hematoma occurs,the risk of rupture increases to 12%.[3,5]

关键词： rupture HELLP hypertension pregnancy

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Mass-Based Environmental Factor and Energy Assessment of Microwave-Assisted Synthesized Transition Metal Nanostructures

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American j.urnal of Analytical Chemistry 2024年第6期15卷 201-218页

作者： victor j. Law School of Mechanical and Materials Engineering University College Dublin Dublin Ireland

This paper describes mass-based energy phase-space proj.ction of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The proj.ction uses process energy budget (measured in kj. on the horizontal axes and process density (measured in kj.−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.

关键词： Microwave-Assisted Synthesis Transition Metals Nanostructures Allometry Scaling Power-Law Signature Green Chemistry

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Mass Spectrometric Analyses Reveal a Central role for Ubiquitylation in Remodeling the Arabidopsis Proteome during Photomorphogenesis

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Molecular Plant 2017年第6期10卷 846-865页

作者： victor Aguilar-Hernandez Do-Young Kim robert j. Stankey Mark Scalf Lloyd M. Smith Richard D. Vierstra Department of Biology Washington University in St. Louis Campus Box 1137 One Brookings Drive St. Louis MO 63130 USA Department of Genetics 425-G Henry Mall Department of Chemistry 1101 University Avenue University of Wisconsin-Madison Madison WI 53706 USA Advanced Bio Convergence Center Pohang Technopark Gyeong-Buk South Korea 37668

The switch from skotomorphogenesis to photomorphogenesis is a key developmental transition in the life of seed plants. While much of the underpinning proteome remodeling is driven by light-induced changes in gene expression, the proteolytic removal of specific proteins by the ubiquitin-26S proteasome system is also likely paramount. Through mass spectrometric analysis of ubiquitylated proteins affinity-purified from etiolated Arabidopsis seedlings before and after red-light irradiation, we identified a number of influential proteins whose ubiquitylation status is modified during this switch. We observed a substantial enrichment for proteins involved in auxin, abscisic acid, ethylene, and brassinosteroid signaling, peroxisome function, disease resistance, protein phosphorylation and light perception, including the phytochrome （Phy） A and phototropin photoreceptors. Soon after red-light treatment, PhyA becomes the dominant ubiquitylated species, with ubiquitin attachment sites mapped to six lysines. A PhyA mutant protected from ubiquitin addition at these sites is substantially more stable in planta upon photoconversion to Pfr and is hyperactive in driving photomorphogenesis. However, light still stimulates ubiquitylation and degradation of this mutant, implying that other attachment sites and/or proteolytic pathways exist. Collectively, we expand the catalog of ubiquitylation targets in Arabidopsis and show that this post- translational modification is central to the rewiring of plants for photoautotrophic growth.

关键词： Arabidopsis ubiquitin mass spectrometry photomorphogenesis phytochrome degradation

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Assessment of k–ε models using tetrahedral grids to describe the turbulent flow field of a PBT impeller and validation through the PIV technique

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Chinese j.urnal of Chemical Engineering 2018年第5期26卷 942-956页

作者： victor X. Mendoza-Escamilla Alej.ndro Alonzo-Garcia Helvio R. Mollinedo Israel Gonzalez-Neria j. Antonio Yanez-Varela Sergio A. Martinez-Delgadillo Depto. Electronica Universidad Autonoma Metropolitana Azcapotzalco Av. San Pablo 180 Azcapotzalco CP 07740 Mexico D.F. Mexico CONACyT-Centro de Ingenierfa y Desarrollo Industrial Av. Piaya Pie de la Cuesta 702 Desarrollo San Pablo 76125 Queretaro Qro. Mexico UPIITA Instituto Politecnico Nacional Av. IPN 2580 G.A. Madero CP 07340 Mexico D.F. Mexico Depto. Ciencias Basicas Universidad Autonoma Metropolitana Azcapotzalco Av. San Pablo 180 Azcapotzalco CP 07740 Mexico D.F Mexico

In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has an impact on the convergence and solution in STRs, and they are used in mixing, multiphase modeling or as starting solution of transient models as DES and LES. Although there are several studies with the pitched blade turbine(PBT) impeller, most of them used the Standard model as representative of all k–ε models, using structured hexahedral grids composed of low number of cells, and in some cases under axial symmetry ***, in this work the assessment of the Standard, RNG and Realizable models to describe the turbulent flow field of this impeller, using the Multiple Reference Frame(MRF) and Sliding Mesh(SM) approaches with tetrahedral domains in dense grids, is presented. This kind of cell elements is especially suitable to reproduce complex geometries. Flow velocities and turbulent parameters were verified experimentally by PIV and torque measurements. The three models were capable of predicting fairly the pumping number, the power number based on torque, and velocities. Although the RNG improved the predictions of the turbulent kinetic energy and dissipation rate, the Realizable model presented better performance for both approaches. All models failed in the prediction of the total dissipation rate, and a dependence of its value on the number of cells for the MRF was found.

关键词： Tetrahedral grids PIV Turbulent flow k-ε models Stirred vessel

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Finite Element Analysis of Residual Stress and Distortion in an Eccentric Ring Induced by Quenching

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材料热处理学报 2004年第05B期25卷 746-751页

作者： LI M. victor Portland State University PO Box 751-ME Portland OR 97207-075J USA

The residual stresses and distortion induced by quenching in an eccentric ring were investigated in this study with finite element method. The ring was made of AISI 52100 steel. A fully coupled 3D temperature-displacement analysis was performed to simulate heat transfer, phase transformations, and mechanical stresses and strains during the heating and subsequent quenching processes. Commercial FEA package ABAQUS/Standard 6.4 was used for the analyses along with user subroutines developed by the authors to model the thermal and mechanical constitutive behavior. The simulation results show that transformation plasticity plays an important role on the residual stress distribution.

关键词：残余应力有限元分析变形偏心环相变塑性

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Increasing effect of metamorphism on rock properties

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International j.urnal of Mining Science and Technology 2015年第2期25卷 205-211页

作者： Akinbinu victor Abioye Department of Mining Engineering Federal University of Technology

This work studied the effect of increasing degree of metamorphism on the properties of *** properties investigated are the physical,mechanical and dynamic *** are important inputs in the design of many mining and civil engineering techniques such as in tunnelling,slope stability and dynamic activities associated with seismicity and *** work compared the degree of metamorphism examined through petrographic studies of the Transvaal Sequence in South Africa with the properties of the *** study shows that as the effect metamorphism increases,the state of stress,compaction of grains,cementation and the brittleness of the rocks *** addition,increase in the metamorphic effect increases the value of the rock *** degree of metamorphism of an outcrop is the key factor influencing its property *** the metamorphism effect of an outcrop may act as a guide to its engineering properties.

关键词： Geology of rock rock property Brittleness Fragmentation and metamorphism

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Malignant cardiac metastasis from breast cancer: Imaging contribution to surgical attitude

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Case Reports in Clinical Medicine 2013年第8期2卷 450-453页

作者： victor j. ovej.ro-gomez L. Martin-Cuesta V. Alij. j. Villalba j. rodríguez-Cabello j. Perez j. M. Baj.-Arenas Department of Cardiology Hospital Sierrallana de Torrelavega Torrelavega Spain Department of Gynaecology Hospital Sierrallana de Torrelavega Torrelavega Spain Department of Medical Oncology Hospital Sierrallana de Torrelavega Torrelavega Spain Department of Radiology Hospital Sierrallana de Torrelavega Torrelavega Spain Department of Surgery Hospital Sierrallana de Torrelavega Torrelavega Spain

Metastasic cardiac disease from the breast is rarely diagnosed in the lifetime. It has a poor prognosis and limited management. Both echocardiography and computerized tomography (CT) should be the first imaging studies in suspicion of this entity. Other diagnostic methods should be based on the possibilities of treatment although a histopathological analysis of the metastasic mass is needed to confirm the diagnosis. Magnetic resonance imaging (MRI) could be useful to complete a morphological and functional evaluation in case of surgical removal.

关键词： Cancer Breast Metastasis Cardiac Imaging

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Influence of Weather Conditions on the Surface Morphology and Wetting Behaviour of Superhydrophobic Quaking Aspen Leaves

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American j.urnal of Plant Sciences 2013年第5期4卷 61-68页

作者： j. j. victor U. Erb Department of Materials Science and Engineering University of Toronto Toronto Canada.

The effects of different environmental conditions on the wetting properties and surface morphology of surperhydrophobic quaking aspen leaves harvested during the 2011 growth season are examined. During this particular season quaking aspen leaves were not able to retain their superhydrophobic properties and associated surface structure features as they have usually been able to do in other years. Representative scanning electron microscopy images and wetting property measurements of quaking aspen leaf surfaces harvested throughout this season are presented and discussed with the obj.ctive of linking weather induced environmental stresses that occurred in 2011 to the sudden and unusual reduction in non-wetting properties and drastic changes in leaf surface structure. Erosion and regeneration rates of leaf wax crystals and the impact that environmental factors can have on these are considered and used to explain the occurrence of these unexpected changes.

关键词： Quaking Aspen Leaves Superhydrophobic Surface Structure Wax Crystal Erosion/Regeneration Weather Conditions

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