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Evaluation of Residual Stresses Induced by High Speed Milling Using an Indentation Method

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Modern Mechanical Engineering 2012年第4期2卷 143-150页

作者： Felipe Díaz Claudio Mammana Armando Guidobono departamento de ingeniería Electromecánica—departamento de ingeniería industrial Facultad Regional Rafaela División Metrología Dimensional Centro Regional Rosario (INTI) Rosario Argentina

In this work, a recently developed method based on the change of distance between collinear indents is used to evaluate different states of residual stress, which were generated in samples of AA 6082-T6 and AA 7075-T6 aluminium alloys milled at high speed. One of the advantages of this method, which needs a universal measuring machine, is not requiring neither the use of specific equipment nor highly skilled operators. Also, by integrating an indentation device to the mentioned machine, the absolute error of measurement can be reduced. In results obtained in samples subjected to different cutting conditions it is observed a correlation between the stress values and the depth of cut, showing the AA 6082-T6 alloy higher susceptibility to be stressed. Furthermore, the high sensitivity of the method allowed detecting very small differences in the values reached by different normal components in the zones corresponding to climb and conventional cutting. It is important to note that these differences were similar for both evaluated alloys. Finally, the directions associated with the principal components of residual stress, where maximum local plastic stretching occurs, were found to be strongly dependent on the rolling direction prior to machining.

关键词： Residual Stresses High Speed Milling Indentation Methods Aluminium Alloys Principal Directions

Reassessment of Prejanopterus curvirostris, a Basal Pterodactyloid Pterosaur from the Early Cretaceous of Spain

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Acta Geologica Sinica(English Edition) 2012年第6期86卷 1389-1401页

作者： Xabier PEREDA-SUBERBIOLA Fabien KNOLL José Ignacio RUIZ-OMEACA Julio COMPANY Fidel TORCIDA FERNNdeZ-BALDOR Universidad del País Vasco/Euskal Herriko Unibertsitatea Facultad de Cienciay TecnologíaDpto.Estratigrafíay Paleontología departamento de Paleobiología Museo Nacional de Ciencias Naturales-CSIC Museo del Jurásico de Asturias (MUJA) departamento de Geología Universidad de Oviedo departamento de ingeniería del Terreno Universidad Politécnica de Valencia Colectivo Arqueológico-Paleontológico de Salas (C.A.S.) Museo de Dinosaurios

Prejanopterus curvirostra, from the Early Cretaceous of La Rioja province, was the first pterosaur genus and species described from Spain. The material comprises disarticulated cranial and postcranial remains from several individuals. The fossil-bearing bed is assigned to the lacustrine Leza Formation （eastern Cameros Basin, NW margin of the Iberian Range）. This unit is regarded as either Berriasian-Valanginian or Barremian-Aptian. Prejanopterus curvirostris （specific name emended） was originally diagnosed on the basis of several characters of which the most significant was a lateral curvature of the rostrum. Re-examination of the holotype （rostrum） and paratype （partial rostrum with teeth） indicates that there is no genuine sideways bend of the preserved premaxilla-maxilla segments, but a slight dorsal curvature. Prejanopterus is characterized by a unique combination of characters： an emended diagnosis is provided. In contrast with previous estimates, the wing span of Prejanopterus was probably not much （if ever） in excess of 2 m. A phylogenetic analysis suggests that Prejanopterus is a basal pterodactyloid positioned between Pterodactylus and Cycnorhamphus- Gallodactylus. Prejanopterus represents the first evidence of Pterodactylidae in the Early Cretaceous of the Iberian Peninsula.

关键词： Pterosauria Prejanopterus Leza Formation Early Cretaceous La Rioja Spain

Recovering information in probabilistic quantum teleportation

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Frontiers of physics 2019年第6期14卷 9-13页

作者： Luis Roa Andrea Espinoza Ariana Munoz Maria L·Ladron de Guevara departamento de Física Universidad de ConcepciónCasilla 160-CConcepciónChile departamento de Física Universidad Católica del NorteAngamos 0610AntofagastaChile Facultad de ingeniería Universidad Autónoma de Chile5 Poniente 1670TalcaChile

In this paper we redesign the probabilistic teleportation scheme considered in ***.A 61,034301(2000)by Wan-Li Li et al.,where the optimal state extraction protocol complements the basic teleportation process with a partially entangled pure state channel,in order to transfer the unknown state with fidelity *** that scheme,where the information of the unknown state is lost if the state extraction fails,our proposal teleports exactly and optimally an unknown state,and allows to recover faithfully that state when the process has not *** order to study the resilience of the scheme,we apply it to the teleportation problem through a quantum channel in a mixed state with pure *** find that a successful process transfers an unfaithful state,namely,the outcome state acquires the decoherence of the channel,but the unknown state is recovered by the sender with fidelity 1 if the teleportation *** addition,in this case,the fidelity of the teleported state has quantum features only if the channel has an amount of entanglement different from zero.

关键词： quantum information teleportation

A New Model for Spreading Malware over SMS Using Network Automata

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Communications and Network 2023年第4期15卷 120-143页

作者： Erick Iván Medina-Salas Ana Lilia Laureano-Cruces Ma. Elena Lárraga-Ramírez Posgrado en Ciencia e ingeniería de la Computación UNAM México City México departamento de Sistemas UAM-A México City México Laboratoire Informatique d’Avignon Avignon France Instituto de ingeniería UNAM México City México

By the year 2026, it is estimated that the number of smartphone users in Mexico will be approximately 118.1 million. Each smartphone has the functionality of sending and receiving SMS (Short Message Service) messages, which pose a significant threat to all users, as it makes any device vulnerable to a malware attack. In particular, worm-type malware takes advantage of this means of communication in order to spread. Studying the dynamics of malware propagation can help understand and prevent massive contagion between mobile devices. In this work, a model based on Network Automata and compartmental epidemiological models is presented, aiming to simulate, analyze and study the spread of worm-like malware through sending SMS on smartphones.

关键词： Cellular Automaton Malware Spread Complex Systems Network Automaton

Strain Influence on the Precipitation Kinetic Nb-V Microalloyed HSLA Steel

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Journal of Iron and Steel Research(International) 2011年第S1期18卷 278-281页

作者： Cartaya Elio Armando Cabrera José María Prado José Manuel departamento de Ciencia de Materiales e ingeniería Metalúrgica ETSEIBUniversidad Politécnica de Catalu a Av.Diagonal 64708028 BarcelonaSpain departamento de Manufactura y Materiales Facultad de Ingeniería MecánicaUniversidad de Oriente90400 Santiago de CubaCuba Fundación CTM Centro Tecnológico Av.Bases de Manresa 108242 ManresaSpain

The strain induced effect on the precipitation kinetics of a high strength low alloy (HSLA) steel microalloyed with Nb-V was *** stress relaxation method was employed to determine the dependence of the precipitation-time-temperature curves (PTT) on previous *** tests were performed over a temperature range of 850 to 1150 oC at a constant strain rate of 0.1 s-1 at three deformation levels,namely 5,15 and 25 *** emission scanning electron microscopy (FESEM) was used to study the progress of precipitation on samples obtained by interrupted relaxation test at different *** display the acceleration kinetics at increasing *** models are discussed and compared with the present experimental results.

关键词： strain induced precipitation kinetic HSLA stress relaxation PTT

Spectrophotometric determination of the formation constants of Calcium(Ⅱ) complexes with 1,2-ethylenediamine,1,3-propanediamine and 1,4-butanediamine in acetonitrile

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Green Energy & Environment 2017年第1期2卷 51-57页

作者： Jacqueline González González Mónica Nájera-Lara Varinia López-Ramírez Juan Antonio Ramírez-Vázquez José J.N.Segoviano-Garfias Programa de Maestría en Biociencias División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca Colegio del Nivel Medio Superior de Salamanca(ENMS) departamento de ingeniería Bioquímica Instituto Tecnológico Superior de Irapuato (ITESI) departamento de Ciencias Ambientales División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca

In this work, with the purpose to explore the coordination chemistry of calcium complexes which could work as a partial model of manganese-calcium cluster, a spectrophotometric study to evaluate the stability of the complexes: Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine in acetonitrile, were carried on. By processing the spectrophotometric data with the HypSpec program allows the determination of the formation constants. The logarithmic values of the formation constants obtained for Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine were log β_(110) = 4.69, log β_(110)= 5.25 and log β_(110) = 4.072, respectively.

关键词： Calcium(Ⅱ)complexes Solution equilibria Artificial photosynthesis Absorbance molar Speciation

In vivo evaluation of additively manufacturedmulti-layered scaffold for the repair of large osteochondral defects

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Bio-design and Manufacturing 2022年第3期5卷 481-496页

作者： Maryam Tamaddon Gordon Blunn Rongwei Tan Pan Yang Xiaodan Sun Shen-Mao Chen Jiajun Luo Ziyu Liu Ling Wang Dichen Li Ricardo Donate Mario Monzón Chaozong Liu Institute of Orthopaedic and Musculoskeletal Science Royal National Orthopaedic HospitalUniversity College LondonStanmore HA74LPUK School of Pharmacy and Biomedical Sciences University of PortsmouthPortsmouth PO12DTUK Guangdong Engineering Research Center of Implantable Medical Polymer Shenzhen Lando Biomaterials Co.Ltd.Shenzhen 518107China School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710054China departamento de ingeniería Mecánica Grupo de Investigación en Fabricación Integrada y AvanzadaUniversidad de Las Palmas de Gran CanariaCampus Universitario de Tafira s/n35017 Las PalmasSpain

The repair of osteochondral defects is one of the major clinical challenges in ***-established osteochondral tissue engineering methods have shown promising results for the early treatment of small ***,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the *** this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion *** developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite *** microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle *** 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage *** histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control *** genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control *** findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.

关键词： Osteochondral scaffold Large animal Additive manufacturing Porous titanium

Performance evaluation of lateral canopy shakers with catch frame for continuous harvesting of oranges for juice industry

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International Journal of Agricultural and Biological Engineering 2020年第3期13卷 88-93,F0002页

作者： Rafael R.Sola-Guirado Sergio Castro-Garcia Gregorio L.Blanco-Roldán Jesús A.Gil-Ribes Emilio J.González-Sánchez Universidad de Córdoba Departamento de Ingeniería RuralE.T.S.I.Agronómica y de MontesCampus de RabanalesCtra.Nacional IV Km 396CordobaSpain

Citrus is mainly oriented to fresh consumption,and harvesting is usually performed ***,the high cost of harvesting and the low availability of labour can compromise the profitability of the crop when it is destined to juice *** development of citrus mechanical harvesting for industrial processing is conditioned to reach a high fruit removal efficiency,with a reduced damage to both fruit and *** current machines available are very large,requiring extensive plantations with long rows of trees to be *** this study,two lateral canopy shakers equipped with a catch frame were evaluated to harvest independently both sides of the hedge on intensive citrus plantations with the main objective of determining their performance and *** lateral canopy shakers tested were three tractor-drawn machines,one commercial machine and two *** tested machines reached a mean value of 78%of fruit ***,the prototypes,equipped with a catch frame,were able to recover a mean value of 70%of *** the results were promising,for achieving an efficient result,the application of this harvesting technology still requires a process of improvement,and the adaptation of both the machine and the *** machines should reduce the amount of post-harvest ground fruit(5.9%-10.4%).Tree damages generated by the contact of the catch frame with the trunk and the metal rods with main branches were the most ***,it is still necessary to increase the ground speed of the machinery and improving the design of the rods,regulating the rod penetrating deep in the canopy to improve the fruit recovery and limit the damage caused to the trees.

关键词： harvester mechanical harvesting fruit removal tree damage Citrus sinensis L.Osbeck

Comparison of *** oxygen plasma and chemical treatments for surface modifications of Ti6Al4V

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Bio-design and Manufacturing 2019年第2期2卷 65-75页

作者： María Elena Alemán.Domínguez Zaida Ortega Antonio N.Benítez Aday Romero.Pérez Ling Wang Ruymán Santana.Farré Francisco Rodríguez.Esparragón departamento de ingeniería de Procesos Universidad de Las Palmas de Gran CanariaCampus universitario de Tafira Baja35017 Las Palmas de Gran CanariaSpain departamento de ingeniería Mecánica Universidad de Las Palmas de Gran CanariaCampus universitario de Tafira Baja35017 Las Palmas de Gran CanariaSpain State Key Laboratory for Manufacturing System Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityScience and Technology Park of Xi’an Jiaotong UniversityYanta DistrictXi’an City 710054Shaanxi ProvincePeople’s Republic of China Research Unit Dr.Negrín University Hospital35019 Las PalmasCanary IslandsSpain

Different treatments were conducted over Ti6Al4V samples in order to produce a surface modification to increase cell attachment and *** surface treatments evaluated in this study were as follows:etching with sulfuric acid/hydrochloric acid,oxidizing with hydrogen peroxide and low-pressure oxygen plasma *** contrast to other works found in the literature,this research conducts a comparison between different chemical and physical treatments in terms of different assays for surface characterization:X-ray diffraction,scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy,water contact angle,release of vanadium ions and cell viability tests(MTT)of human osteoblasts(hFOB 1.19).Cell morphology over the different substrates was also studied by SEM *** was found that plasma and peroxide treatments increase the O/Ti ratio at the titanium surface and provide an increase in cell *** the other hand,acid etching provides a superhydrophilic surface which is not able to improve the cell attachment of human osteoblasts.

关键词： Surface activation Titanium alloys Surface functionalization Low-pressure plasma