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Neural Network-Based Second Order Reliability Method(NNBSORM)for Laminated Composite Plates in Free Vibration

Computer Modeling in engineering & Sciences 2018年第4期115卷 105-129页

作者： mena e.tawfik Peter L.Bishay edward e.Sadek Aerospace engineering Department Faculty of EngineeringCairo UniversityEgypt Mechanical and Aerospace engineering Department Rutgersthe State University of New JerseyNew BrunswickNJUSA Mechanical engineering Department College of Engineering and Computer ScienceCalifornia State UniversityNorthridgeCAUSA.

Monte Carlo Simulations(MCS),commonly used for reliability analysis,require a large amount of data points to obtain acceptable accuracy,even if the Subset Simulation with Importance Sampling(SS/IS)methods are *** Second Order Reliability Method(SORM)has proved to be an excellent rapid tool in the stochastic analysis of laminated composite structures,when compared to the slower MCS ***,SORM requires differentiating the performance function with respect to each of the random variables involved in the *** most suitable approach to do this is to use a symbolic solver,which renders the simulations very slow,although still faster than ***,the inability to obtain the derivative of the performance function with respect to some parameters,such as ply thickness,limits the capabilities of the classical *** this work,a Neural Network-Based Second Order Reliability Method(NNBSORM)is developed to replace the finite element algorithm in the stochastic analysis of laminated composite plates in free *** of the ability to obtain expressions for the first and second derivatives of the NN system outputs with respect to any of its inputs,such as material properties,ply thicknesses and orientation angles,the need for using a symbolic solver to calculate the derivatives of the performance function no longer *** proposed approach is accordingly much faster,and easily allows for the consideration of ply thickness *** present analysis showed that dealing with ply thicknesses as random variables results in 37%increase in the laminate’s probability of failure.

关键词： Reliability analysis artificial neural network composite laminates subset simulation importance sampling Monte Carlo

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A Note on extreme Points in Dual Spaces

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Acta Mathematica Sinica,english Series 2013年第3期29卷 471-476页

作者： Juan Francisco mena-JURADO Juan Carlos NAVARRO-PASCUAL Departamento de Análisis Matemático Facultad de Ciencias Universidad de Granada Departamento de lgebra y Análisis Matemático Universidad de Almería

Given a normed space X it can be easily proven that every extreme point in Bx＊, the unit ball of X＊, is the restriction of an extreme point in Bx Our purpose is to study when the restrictions of extreme points in B... 详细信息

关键词： extreme point Ll-predual M-ideal

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Governance in the exploration of global and regional determinants of ICT development

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International Journal of Innovation Studies 2024年第2期8卷 132-153页

作者： Charles S.Saba Simplice A.Asongu Nicholas Ngepah Yolande e.Ngoungou School of economics College of Business and EconomicsUniversity of JohannesburgJohannesburgSouth Africa Department of econornic&Data Science New Uzbekistan University54 Mustaili AvenueTashkent100007Uzbekistan University of Yaounde 2 SoaCameroon

The present study assesses how governance affects information and communication technology(IcT)at the global level contingent on macroeconomic policy factors such as trade,foreign direct investment(FDI),manufacturing value added,and agricultural value *** study focuses on 183 countries from 2003 to 2021,and the empirical evidence is based on the generalized method of moments(GMM).The following main findings are *** the full sample,governance unconditionally promotes ICT development,while trade openness(industrial added value)moderates governance to promote(dampen)ICT *** sub-Saharan Africa,only trade openness effectively moderates governance to induce an overall positive effect on ICT,while in the Middle east and North Africa(mena)region,all policy variables moderate governance for an overall positive incidence on ICT sector *** findings for the mena region are confirmed in the europe and Central Asia(eCA)region,with the exception of the moderating role of industrial added value,which engenders an overall negative *** the east and South Asia and the Pacific(eSAP)countries,one overall positive incidence is apparent in the role of trade openness,while net negative effects are established from the moderating roles of industrial added value and agricultural added *** the American sub-sample,a positive(negative)net effect is apparent from the role of industrial added value(trade)in moderating the incidence of gover-nance on ICT sector ***,policy implications are discussed.

关键词： ICT Governance Trade FDI Industry Agriculture

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Host-parasite interactions in perpetual darkness:Macroparasite diversity in the cavefish Astyanax mexicanus

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Zoological Research 2023年第4期44卷 782-792页

作者： Ana Santacruz David Hernández-mena Ramses Miranda-Gamboa Gerardo Pérez-Ponce De León Claudia Patricia Ornelas-García Departamento de Zoología Instituto de BiologíaUniversidad Nacional Autónoma de MéxicoMéxico City CP 04510México Departamento de Sistemas y Procesos Naturales Escuela Nacional de Estudios Superiores Unidad MéridaUcúYucatán CP 97357México Instituto de energías Renovables Universidad Nacional Autónoma de MéxicoTemixcoMorelos CP 62580México Colección Nacional de Peces Departamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoMéxico City CP 04510México Stowers Institute for Medical Research Kansas CityMO 64110USA

Astyanax mexicanus has repeatedly colonized cave environments,displaying evolutionary parallelisms in many troglobitic *** being a model system for the study of adaptation to life in perpetual darkness,the parasites that infect cavefish are practically *** this study,we investigated the macroparasite communities in 18 cavefish populations from independent lineages and compared them with the parasite diversity found in their sister surface fish populations,with the aim of better understanding the role that parasites play in the colonization of new *** the cavefish populations,we identified 13 parasite taxa,including a subset of 10 of the 27 parasite taxa known for the surface *** infecting the cavefish belong to five taxonomic groups,including trematodes,monogeneans,nematodes,copepods,and *** are the most dominant group,found in 14 *** macroparasites include species with direct life cycles and trophic transmission,including invasive ***,paired comparisons indicate higher parasite richness in the cavefish than in the surface *** variation in parasite composition across the caves suggests historical and geographical contingencies in the host-parasite colonization process and potential evolution of local *** base-line data on parasite diversity in cavefish populations of *** provides a foundation to explore the role of divergent parasite infections under contrasting ecological pressures(cave *** environments)in the evolution of cave adaptive traits.

关键词： Adaptation Metazoan parasites Niche change Parasite assemblage Prevalence

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Biochar from grape pomace,a waste of vitivinicultural origin,is effective for root-knot nematode control

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Biochar 2023年第1期5卷 519-541页

作者： Ángela Martínez-Gómez Maria Fe Andrés Ángel Barón-Sola Fernando e.Díaz-Manzano Ibraheem Yousef Ismael F.mena elena Díaz Óscar Gómez-Torres Azucena González-Coloma Luis e.Hernández Carolina escobar Facultad de Ciencias Ambientales y Bioquímica Universidad de Castilla-La ManchaToledoSpain Departamento de Protección Vegetal Instituto Ciencias Agrarias CSICMadridSpain Departamento de Biología Universidad Autónoma de MadridMadridSpain CeLLS ALBA Carrer del Llum 2-2608290Cerdanyola del VallèsBarcelonaSpain Departamento de Ingeniería Química Universidad Autónoma de MadridMadridSpain Faculty of Chemical Sciences&Technologies Chemical Engineering DepartmentAv.Camilo JoséCela1213071University of Castilla-La ManchaCiudad RealSpain

Root-knot nematodes(RKNs)are obligate endoparasites that feed on their host plants to complete its life cycle,representing a major threat to agriculture and economy *** development of new management strategies becomes essential as effective chemical nematicides are progressively being ***,we analysed grape pomace-derived biochars,pyrolysed at 350°C(BC350)and 700°C(BC700),focusing on their potential for RKN *** thermal treatment of grape pomace caused an increase in the concentration of carbon and plant macro-and micronutrients,which were largely present in a water-soluble *** radiation-based Fourier transform infrared microspectroscopy data showed a general loss of carboxylic functional groups during pyrolysis,partially contributing to the alkalinisation of both biochars,mostly in *** electron microscopy coupled with energydispersive X-ray spectroscopy analysis revealed a highly porous structure filled with different crystals composed of elements such as K,Ca,Mg,P,Si or Al,which could be a suitable environment for the growth of ***-derived aqueous extracts showed phytotoxicity to tomato seedlings at high concentrations,and disappeared upon dilution,but no toxic effect was observed on the nematode’s infective ***,the infective and reproductive traits of a Meloidogyne javanica population in tomato were significantly reduced(*** masses and eggs per plant)in washed-biochar-treated soil in pots(0.75%;BC350W).Therefore,the large amount of grape waste generated after wine production can be transformed into a valuable product such as biochar,effective for RKNs control,thus reducing the waste management problem and contributing to a circular economy.

关键词： Biochar Grape pomace Tomato Root-knot nematode control Meloidogyne spp.

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Green Gold—Dirty Gold, Tadó, Dept. Chocó, Colombia

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Natural Resources 2015年第11期6卷 534-542页

作者： William e. Brooks Julio Andrés Sierra-Giraldo Franciso mena Palacios Geologist Reston VA USA Herbario FAUC Universidad de Caldas Manizales Colombia Joyero William Chin Quibdó Colombia

In place of mercury, small-scale alluvial gold miners in Tadó, Dept. Chocó, Colombia produce “green gold” (oroverde) using locally available plant extracts. The leaves of Balso (Ochroma pyramidale) and Malva (Hibiscus furcellatus) are crushed by hand and are mixed with water to make a foamy liquid that is added to the gold pan (batea) instead of mercury. After the plant extract is added, the gold, magnetite, and other heavy minerals sink and the lighter minerals are floated out of the gold pan. For final clean-up, a combination of other methods may be used. However, ICP (Inductively Coupled Plasma) analyses indicate that even green gold contains 208 - 4530 ppm Hg—this mercury may have been released from dragas or other small-scale gold mining operations that continue to use mercury;coal burning;volcanism;or native mercury released from cinnabar occurrences. ICP also indicates 308 - 106,000 ppm Ag and 452 - 585 ppm Pt.

关键词： Green Gold Mercury Geochemistry Plants Colombia

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A new physical simulation tool to predict the interface of dissimilar aluminum to steel welds performed by friction melt bonding

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Journal of Materials Science & Technology 2019年第9期35卷 2048-2057页

作者： T.Sapanathan N. Jimenez-mena I. Sabirov M.A. Monclus J.M. Molina-Aldaregui P. Xia L. Zhao A. Simar Institute of Mechanics Materials and Civil EngineeringUCLouvain1348 Louvain-la-NeuveBelgium IMDeA Materials Institute Calle Eric Kandel 228906 GetafeMadridSpain Universidad Politicnica de Madrid E.T.S. de Ingenieros de Caminos28040 MadridSpain

Optimization of the intermetallic layer thickness and the suppression of interfacial defects are key elements to improve the load bearing capacity of dissimilar joints. However, till date we do not have a systematic tool to investigate the dissimilar joints and the intermetallic properties produced by a welding condition. Friction Melt Bonding (FMB) is a recently developed technique for joining dissimilar metals that also does not exempt to these challenges. The FMB of DP980 and A16061-T6 was investigated using a new physical simulation tool, based on Gleeble thermo-mechanical simulator, to understand the effect of individual parameter on the intermetallic formation. The proposed method demonstrates its capability in reproducing the intermetallic characteristics, including the thickness of intermetallic bonding layer, the morphology and texture of its constituents (Fe2AU and Fe4Ali3), as well as their nanohardness and reduced modulus. The advantages of physical simulation tool can enable novel developing routes for the development of dissimilar metal joining processes and facilitate to reach the requiring load bearing capacity of the joints.

关键词： Physical simulation Interface Intermetallics Nanoindentation Joining

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Hopf Bifurcation Control in a Lorenz Type System

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Journal of Applied Mathematics and Physics 2018年第8期6卷 1704-1719页

作者： P. e. Calderon-Saavedra e. Munoz-Aguirre J. Alvarez-mena S. Gomez-Perez Universidad del Tolima Ibagué Colombia Universidad Veracruzana Veracruz Mexico

In this paper Hopf bifurcation control is implemented in order to change the bifurcation from supercritical to subcritical in a differential equations system of Lorenz type. To achieve this purpose: first, a region of parameters is identified where the system has a supercritical Hopf bifurcation;second, a class of non-linear feedback control laws is proposed;finally, it is shown that there are control laws which the disturbed system undergoes subcritical Hopf bifurcation.

关键词： Lorenz Type Systems Bifurcation Control Hopf Bifurcation Control Subcritical and Supercritical Hopf Bifurcation

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Research on arbuscular mycorrhizae in Cuba:a historical review and future perspectives

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Studies in Fungi 2021年第1期6卷 240-262页

作者： Furrazola e Torres-Arias Y Ojeda-Quintana L Fors RO Rodríguez-Rodríguez R Ley-Rivas JF mena A González-González S Berbara RLL Queiroz MB Hamel C Goto BT Instituto de ecología y Sistemática CITMA Carretera Varona 11835 e/Oriente y LinderoLa Havana 19CalabazarBoyerosLa HavanaCuba CUM Cumanayagua Universidad de Cienfuegos“Carlos R.Rodríguez”CienfuegosCuba Universidade Federal Rural do Rio de Janeiro Instituto de AgronomiaSeropedicaRJBrazil Instituto Nacional de Ciencias Agropecuarias(INCA) Gaveta Postal 1San Joséde las LajasMayabequeCuba Universidad de Temuco Chile Programa de Pós-graduação em Sistemática e evolução CBUniversidade Federal do Rio Grande do NorteCampus Universitário59072-970NatalRNBrazil Quebec Research and Development Centre Agriculture and Agri-Food Canada2560 Hochelaga BlvdQuebec CityQCCanada G1V 2J3

This review presents the development of researches on arbuscular mycorrhizae(AM)conducted in Cuba,a tropical Caribbean island rich in *** key findings from this work are highlighted and presented as a stepping stone for future *** research has contributed to understand the diversity and functionality of AM in several tropical ecosystems,mainly evergreen forests,agroecosystems,sand dunes and *** were conducted in 10 out of 16 provinces reported 79 AM species,representing 25%of the known species *** researchers have a great deal of expertise in Glomeromycota taxonomy and have described 11 new species,of which six were not reported elsewhere in the ***,important studies conducted in Cuba have shed light on the mycotrophic plants,the role of AM in forest ecosystems,and their use in crop *** contribution of AM to ecosystem processes is a priority line of *** and multidisciplinary researches are necessary to define the role of AM symbioses and improve biogeochemical *** created Cuban Mycorrhizal Research Network will help to coordinate validation campaigns for various biofertilizers with training courses for Cuban farmers to disseminate the key results on *** the challenges for Cuban mycorrhizologists,molecular(genomic)techniques,stable isotopes and nuclear magnetic resonance should also be included as priority lines of research in the future.

关键词： Arbuscular mycorrhizal fungi diversity ecosystems mycorrhizal research symbiotic associations

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Prevalence of hepatocarcinoma-related hepatitis B virus mutants in patients in grey zone of treatment

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World Journal of Gastroenterology 2019年第38期25卷 5883-5896页

作者： Ana Isabel Gil-García Antonio Madejón Irene Francisco-Recuero Ana López-López emiliana Villafranca Miriam Romero Araceli García Antonio Olveira Rocío mena Juan Ramón Larrubia Javier García-Samaniego Hepatology Unit Hospital Universitario La PazMadrid 28046Spain Centro de Investigación Biomédica en Red Instituto de Salud Carlos IIIMadrid 28029Spain Instituto de Investigación del Hospital Universitario la Paz Madrid 28046Spain Biochemistry Department Faculty of MedicineUniversidad Autónoma de MadridMadrid 28029Spain Instituto de Genética Médica y Molecular Hospital Universitario La PazMadrid 28046Spain Translational Hepatology Unit Hospital General Universitario de GuadalajaraGuadalajara 19002Castilla-La ManchaSpain

BACKGROUND Antiviral treatment of patients with chronic hepatitis B(CHB)in the grey zone of treatment comands risk management in order to optimize the health *** this sense,the identification of HBV mutants related with an increased risk of hepatocellular carcinoma(HCC)could be useful to identify subpopulations with potential indication of antiviral *** To analyze the prevalence/persistence of hepatitis B virus(HBV)preS and basal core promoter(BCP)/precore/core variants associated to HCC development in CHB patients in the grey *** Work was designed as a longitudinal retrospective study,including 106 plasma samples from 31 patients with CHB in the grey zone of treatment:Hepatitis B e antigen negative,HBV-DNA levels between 12-20000 IU/mL,normal or discordant transaminase levels during follow up and mild/moderate necroinflammatory activity in liver biopsy or Fibroscan(up to 9.5 kPa).Serum HBVDNA was tested using the Abbott Real Time HBV Assay and the BCP/precore/core and the hepatitis B surface antigen(HBsAg)coding regions were analyzed in positive samples by PCR/bulk-sequencing to identify the HCCrelated HBV *** High-risk HCC related mutants were detected in 24(77%)patients:19(61%)in the BCP/precore/core,and 7(23%)in the HBsAg coding region(2 preS1 and 5 preS2 deletions).The prevalence of preS deletions was genotype-dependent:3/5(60%)patients with preS2 deletions and 1/2 with preS1 deletions were infected with the HBV-e *** HBV-e was the most prevalent in sub-Saharan patients,a correlation between preS deletions and ethnicity was also found:6/8(75%)sub-Saharan vs 1/19(5%)Caucasian patients had preS deletions(P=0.00016).Remarkably,this correlation was maintained in those patients infected with HBV-A,a minor genotype in sub-Saharan patients:2/2 patients infected with HBV-A from West Africa vs 0/6 of Caucasian origin had preS *** HCC related variants were the major strains and persisted over time(up to 48 mo).Pa

关键词： Hepatitis B virus Hepatocellular carcinoma PreS deletions Hepatitis B virus treatment Grey zone

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