bluuebunny/crossref_metadata_2025 huggingface dataset:
MGuard Embolic Protection Stent – The Importance of Thrombus Management in ST-elevation Myocardial Infarction Primary Percutaneous Coronary Intervention
Authors: Mountfort Katrina , Costa Ricardo , Abizaid Alexandre , Fajadet Jean , Lotan Chaim , Kornowski Ran , Dudek Dariusz , Henriques Jose PS , Amoroso Giovanni ,   Medical Writer, Radcliffe Cardiology, 7/8 Woodlands Farm, Cookham Dean, Berks, SL6 9PN. E: katsmountfort@virginmedia.com,   Dante Pazzanese Institute, Sao Paulo, Brazil,   Dante Pazzanese Institute, Sao Paulo, Brazil,   Clinique Pasteur, Toulouse, France,   Hadassah-Hebrew University Hospital, Jerusalem, Israel,   Rabin Medical Center, Petach Tikva, Israel,   Department of Interventional Cardiology, Jagiellonian University, Krakow, Poland,   Academic Medical Centre, Amsterdam, The Netherlands,   Onze Lieve Vrouwe Gasthuis Hospital, Amsterdam, The Netherlands
Published: September 2014

Distal embolisation of atherothrombotic material is a frequent consequence of percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI). This causes microvascular occlusions, leading to a further reduction in myocardial reperfusion. The MGuard™ embolic protection stent (EPS) features a unique polymer micronet mesh coating. When used in acute STEMI, the MGuard EPS shows significant improvement in myocardial flow and ST resolution, even in complicated clinical cases vs the standard approach with conventional bare metal or drug-eluting stents. Data from the andomised Safety and Efficacy Study of MGuard Stent After a Heart Attack (MASTER II) trial and from a real-life registry have shown the efficacy and safety of the MGuard in primary PCI. This report of the proceedings of a symposium at EuroPCR, 20–23 May 2014, Paris, France, discussed clinical trial data, as well as a number of clinical cases, illustrating the utility of the MGuard EPS in difficult situations.
Bioresorbable Scaffolds
Authors: Panaich Sidakpal , Schreiber Theodore , Grines Cindy ,   Department of Cardiology, Detroit Medical Center, Michigan, US,   Department of Cardiology, Detroit Medical Center, Michigan, US,   Department of Cardiology, Detroit Medical Center, Cardiovascular Institute, 311 Mack Ave, Detroit, MI 48201, US. E: cgrines@dmc.org
Published: September 2014

Percutaneous coronary intervention (PCI) has undergone major advances including the evolution in stent technology, from bare metal stents (BMS), to their drug eluting counterparts, to the development of bioresorbable scaffolds (BRS). The primary notion of BRS was to facilitate complete vascular healing and restore normal endothelial function following the resorption of stent scaffold while providing equivalent mechanical properties of a metallic drug eluting stents (DES) in the earlier stages. BRS provide attractive physiologic advancements over the existing DES and have shown promising results in initial clinical studies albeit with small sample sizes. Their use has been primarily restricted to patients recruited in clinical trials with limited real-world applicability. Thus, data from larger randomised control trials is awaited. The major objective of this article is to review the evidence on BRS and identify their clinical applicability in current interventional practice.
Meeting the Unmet – The Cre8 Polymer-free Drug-eluting Stents Technology
Authors: Mountfort Katrina , Carrié Didier , Valgimigli Marco , Sardella Gennaro , Banai Shmuel , Romaguera Rafael , Stella Pieter ,   Medical Writer, Radcliffe Cardiology, 7/8 Woodlands Farm, Cookham Dean, Berks, SL6 9PN. E: katsmountfort@virginmedia.com,   Centre Hospitalier Universitaire Rangueil, Toulouse, France,   The University Hospital of Ferrara, Ferrara, Italy,   Policlinico “Umberto I,” “Sapienza” University, Rome, Italy,   Tel Aviv Medical Center, Tel Aviv, Israel,   Hospital Universitari de Bellvitge-IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain,   University Medical Centre Utrecht, The Netherlands
Published: September 2014

The use of first-generation drug-eluting stents (DES) has been associated with safety concerns such as very late stent thrombosis. Today, with the release of newer DES, there is a need for comparative studies of percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) to demonstrate their value in patients with high risk of restenosis such as diabetic patients. In a satellite symposium presented at EuroPCR 2014, the Cre8™ DES was discussed. The Cre8 device has a number of unique clinical features, including polymer-free technology, abluminal reservoir technology and bio-inducer surface that ensure effective neointima suppression and rapid endothelialisation. The efficacy of the Cre8 DES has been demonstrated in the International randomised comparison between DES Limus Carbostent and Taxus drug-eluting stents in the treatment of de novo coronary lesions (NEXT) randomised clinical study, with equivalent efficacy in the diabetic and general populations, a unique finding. Ongoing clinical studies such as Investig8 and the Tel Aviv Medical Center (TLVMC) Cre8 study have confirmed the efficacy of the device in patient populations with a high proportion of diabetic patients. The Demonstr8 randomised trial has shown almost complete Cre8 strut coverage at three months with a numerical advantage versus bare metal stent (bare metal stents [BMS] – comparator device) at one month. In addition, use of the Cre8 DES may enable a shorter duration of dual antiplatelet therapy (DAPT) following PCI. The Cre8 DES therefore represents a significant advance in stent technology and may be particularly useful in challenging clinical settings
Evidence for Benefit of Percutaneous Coronary Intervention for Chronically Occluded Coronary Arteries (CTO) – Clinical and Health Economic Outcomes
Authors: Rawlins John , Wilkinson James , Curzen Nick ,   Wessex Cardiothoracic Centre, University Hospital Southampton NHS Trust,   Wessex Cardiothoracic Centre, University Hospital Southampton NHS Trust,   Wessex Cardiothoracic Centre, Cardiothoracic Department, University Hospital Southampton, Tremona Road, SO16 6YD. E: nick.curzen@uhs.nhs.uk; Faculty of Medicine, University of Southampton
Published: September 2014

Percutaneous revascularisation of a coronary chronic total occlusion (CTO) remains one of the technical frontiers of interventional cardiology. CTOs are common, and yet intervention is only attempted in 10 % of cases. CTO procedures are perceived to be technically challenging, lengthy, associated with significant risk and have only limited data to support the practise. Recent technical advances have dramatically increased the success rate, shortened procedural time and improved clinical outcomes. The aim of this article is to critically examine the data that supports CTO intervention, including specifically an appraisal of procedural safety, benefit and overall cost effectiveness.
Percutaneous Treatment of Coronary Chronic Total Occlusions Part 1: Rationale and Outcomes
Authors: Galassi Alfredo , Grantham Aaron , Kandzari David , Lombardi William , Moussa Issam , Thompson Craig , Werner Gerald , Chambers Charles , Brilakis Emmanouil ,   University of Catania, Catania, Italy,   Saint Luke’s Mid America Heart Institute and University of Missouri Kansas City, Missouri, US,   Piedmont Heart Institute, Atlanta, Georgia, US,   University of Washington, Seattle, US,   Mayo Clinic, Jacksonville, Florida, US,   Boston Scientific, Natick, Massachusetts, US,   Klinikum Darmstadt, Darmstadt, Germany,   Penn State University College of Medicine, Hershey, Pennsylvania, US,   VA North Texas Health Care System, The University of Texas Southwestern Medical Center at Dallas, Division of Cardiology (111A), 4500 S. Lancaster Rd, Dallas, TX, US 75216. E: esbrilakis@gmail.com
Published: September 2014

Coronary chronic total occlusions (CTOs) are commonly encountered in patients with coronary artery disease. Compared to patients without coronary CTOs, those with CTO have worse clinical outcomes and lower likelihood of complete coronary revascularisation. Successful CTO percutaneous coronary intervention (PCI) can significantly improve angina and improve left ventricular function. Although currently unproven, successful CTO PCI might also reduce the risk for arrhythmic events in patients with ischaemic cardiomyopathy, provide better tolerance of future acute coronary syndrome, and possibly improve survival. Evaluation by a heart team comprised of both interventional and non-interventional cardiologists and cardiac surgeons is important for determining the optimal revascularisation strategy in patients with coronary artery disease and CTOs. Ad hoc CTO PCI is generally not recommended, so as to allow sufficient time for (a) discussion with the patient about the indications, goals, risks, and alternatives to PCI; (b) careful procedural planning; and (c) contrast and radiation exposure minimisation. Use of drug-eluting stents is recommended for CTO PCI, given the lower rates of angiographic restenosis compared to bare metal stents.
Percutaneous Treatment of Coronary Chronic Total Occlusion Part 2: Technical Approach
Authors: Galassi Alfredo , Grantham Aaron , Kandzari David , Lombardi William , Moussa Issam , Thompson Craig , Werner Gerald , Chambers Charles , Brilakis Emmanouil ,   University of Catania, Catania, Italy,   Saint Luke’s Mid America Heart Institute and University of Missouri Kansas City, Missouri, US,   Piedmont Heart Institute, Atlanta, Georgia, US,   University of Washington, Seattle, US,   Mayo Clinic, Jacksonville, Florida, US,   Boston Scientific, Natick, Massachusetts, US,   Klinikum Darmstadt, Darmstadt, Germany,   Penn State University College of Medicine, Hershey, Pennsylvania, US,   VA North Texas Health Care System, The University of Texas Southwestern Medical Center at Dallas, Division of Cardiology (111A), 4500 S. Lancaster Rd, Dallas, TX, US 75216. E: esbrilakis@gmail.com
Published: September 2014

Dual injection is recommended for nearly all chronic total occlusion (CTO) percutaneous coronary intervention (PCI) to determine the optimal crossing strategy and guide wire advancement into the distal true lumen. Strategies that provide enhanced guide catheter support (such as long sheaths, large-bore guiding catheters, use of guide catheter extensions, and anchor techniques) are important for maximising the success rate and efficiency of CTO PCI. Use of a microcatheter or over-the-wire balloon is strongly recommended in CTO PCI for enhancing the penetrating power of the guidewire, enabling change in tip shape and allowing guidewire change (stiff CTO guidewires are not optimal for crossing non-occluded coronary segments). Adherence to a procedural strategy that standardises CTO technique and facilitates procedural success is recommended. Such a strategy would permit stepwise decision-making for antegrade and retrograde methods; inform guidewire selection; and incorporate alternative approaches for instances of initial failure. Given the paucity of long-term outcomes with use of novel crossing techniques (antegrade dissection/re-entry and retrograde), antegrade wire escalation is the preferred CTO crossing technique, if technically feasible. Using measures to minimise radiation exposure (including but not limited to use of 7.5 frames per second fluoroscopy and use of low magnification) and contrast administration is recommended. CTO PCI is best performed at centres with dedicated CTO PCI experience and expertise. Use of crossing difficulty prediction tools, such as the J-CTO score, can facilitate the selection of cases with a high likelihood of quick crossing that can be attempted at less experienced centres.
New Advances in Chronic Total Occlusions
Authors: Konstantinidis Nikolaos , Pighi Michele , Kilic Ismail Dogu , Serdoz Roberta , Sianos Georgios , Di Mario Carlo ,   National Institute for Health Research (NIHR) Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, London, United Kingdom; 1st Cardiology Department, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece,   National Institute for Health Research (NIHR) Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, London, United Kingdom,   National Institute for Health Research (NIHR) Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, London, United Kingdom,   National Institute for Health Research (NIHR) Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, London, United Kingdom,   1st Cardiology Department, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece,   National Institute for Health Research (NIHR) Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust, NIHR Cardiovascular BRU, Royal Brompton Hospital, Sydney Street, London SW3 6NP. E: c.dimario@rbht.nhs.uk
Published: September 2014

Coronary chronic total occlusions (CTOs) still represent the greatest technical challenge that interventional cardiologists face. CTOs remain seriously undertreated with percutaneous techniques, far below their prevalence. One reason for the low uptake was the suboptimal CTO percutaneous coronary intervention (PCI) success rates over a long period of time. During the last years, dedicated groups of experts in Japan, Europe and United States fostered the development and standardisation of modern CTO recanalisation techniques, along with providing focused training and proctorship worldwide. As a result, dedicated operators achieved success rates far beyond 90 %, while coping with lesions of increasing complexity. A series of studies, mainly retrospective and observational in nature, explored the prognostic impact of CTO PCI, revealing that successful lesion recanalisation is related to improved patient outcome and anginal status; further evidence from randomised trials is on the way. The following review reports on the most recent advances in the field of CTO recanalisation, in an attempt to promote a more balanced approach in patients with chronically occluded coronary arteries and encourage more operators to cope with these inherently complex lesions.
Contemporary Techniques for Coronary Chronic Total Occlusions Revascularisation: Sharing Experience in a Global World
Authors: Mountfort Katrina , Büttner Heinz Joachim , Yamane Masahisa , Reifart Nicolaus , Escaned Javier , Sianos Georgios , Goktekin Omer , Garbo Roberto ,   Medical Writer, Radcliffe Cardiology, 7/8 Woodlands Farm, Cookham Dean, Berks, SL6 9PN. E: katsmountfort@virginmedia.com,   Universitaets-Herzzentrum Freiburg, Bad Krozingen, Germany,   Sayama Hospital, Saitama, Japan,   Main Taunus Kliniken, Bad Soden, Germany,   Clinico San Carlos University Hospital, Madrid, Spain,   AHEPA University Hospital, Thessaloniki, Greece,   Bezmialem Vakıf University, Istanbul, Turkey,   Ospedale San Giovanni Bosco, Torino, Italy
Published: September 2014

Chronic total occlusions (CTO) are the most challenging lesions treated by interventional cardiologists. A symposium at EuroPCR 2014 discussed factors influencing the success of percutaneous intervention (PCI) in CTO. Current treatment paradigms suggest that one or two vessel disease should be treated by PCI while three-vessel disease requires surgery if complete revascularisation cannot be achieved with PCI. In patients with CTO and multi-vessel disease timing is key, and evidence of ischaemic burden and expected completeness of revascularisation is required before PCI is undertaken. Other factors affecting procedural success include the available equipment and expertise of the operator. Flexiblity in strategy selection is also important as it is frequently necessary to switch strategies during the procedure. The presentation included two live cases that illustrated the complexity of this procedure.
Çocukların vücut ağırlığı ve görünümleri ile iştahları hakkındaki ebeveyn değerlendirmelerinin nesnel ölçütlerle ilişkisi?
Authors: Peker Emel , Topaloğlu Naci , Şahin Erkan Melih , Eşsizoğlu Ertan , Uludağ Ayşegül , Güngör Selen , Ağaoğlu Hasret
Published: September 2014

Amaç: Ebeveynlerin çoğunun çocuklarının vücut ağırlığı ya da iştahları ile ilgili endişelerinin olması çok yaygın bir durumdur. Hekimler ebeveynlerin çocukları hakkındaki yargılarına güvenmezler. Bu çalışmada ebeveynlerin, çocuklarının vücut ağırlığı ve görünümleri hakkındaki görsel algısı ile iştahları hakkındaki yargılarının, çocuklarının ve kendilerinin beden kitle indeksi (BKİ) gibi nesnel ölçütlerle karşılaştırmalı olarak incelenmesi amaçlanmıştır.Yöntem: Çanakkale Onsekiz Mart Üniversitesi Tıp Fakültesi Eğitim ve Araştırma Hastanesi Çocuk Sağlığı ve Hastalıkları Polikliniğine Ocak-Şubat 2012 tarihleri arasında herhangi bir yakınma ile başvuran, ortalama yaşları 6,4±2,8 (2-14 yaş arası) olan 150 çocuk ile anne veya babaları çalışmaya alındı. Ebeveyn ve çocukların BKİ değerleri ile çocukların yaşa göre BKİ persentilleri hesaplandı. Ebeveynlerden, çocuklarının iştahını nasıl değerlendirdikleri sorulup, çocuklarının görünümünü yaş grupları ve cinsiyete göre beden gelişimi için hazırlanmış zayıftan obeze değişen 7 setlik resimlerden uygun bulduklarıyla eşleştirmeleri istendi.Bulgular: Çocukların gerçek BKİ persentil aralıklarıyla karşılaştırıldığında, ebeveynlerin görseller üzerinden yaptığı eşleştirmelerde 55 (%36,7) çocuğun olduğundan daha zayıf değerlendirildiği görüldü. İki değerlendirme arasındaki fark ebeveynlerin veya çocuğun cinsiyetine göre farklılık oluşturmuyordu ve çocuğun yaşı, ebeveyn eğitimi veya BKİ değeri ile korele değildi.Sonuç: Ebeveynlerin çocuklarının vücut ağırlığı ve iştahı hakkındaki algıları ve değerlendirmeleri çocuğun durumunu nesnel olarak yansıtmamaktadır. Ebeveynlerle çocukların vücut ağırlığı ve iştahları hakkında konuşmak çocuk sağlığı danışmanlığının temel parçalarından biri haline getirilmelidir.
Bedside lung ultrasound versus chest X-ray use in the emergency department
Authors: Ünlüer Erden , Karagöz Arif
Published: September 2014

Acute dyspnoea is one of the most common reasons patients present to the emergency departments (ED). In most cases, the physical examination and bedside radiographs are inconclusive, resulting in the need for more sophisticated diagnostics. These diagnostics may delay treatment or expose the patient to unnecessary radiation. Here, we present the case of a dyspnoeic patient with a normal chest X-ray. The patient was diagnosed with pneumonia by bedside lung ultrasound (BLUS). BLUS revealed bilateral pleural effusion, which was more significant on the right side of the thorax. The right lower lung lobe was consolidated and quad, sinusoid and shred signs were present on BLUS. Chest X-rays demonstrated normal findings. Based on this discrepancy, computerised tomography (CT) of the chest was ordered. A consolidated right lower lung lobe was clearly appreciated with bilateral pleural effusion. However, this finding was not observed on the chest X-ray. Because of the dynamic nature of the disease process, we were able to diagnose pathological changes in the lung earlier with the use of BLUS. In conclusion, this modality may replace the chest X-ray in the ED because it can be used bedside, has high accuracy, and minimal cost.
Non-linear dynamical analysis of imperfect functionally graded material shallow shells
Authors: Bich Dao Huy , Long Vu Do
Published: September 2014

Dynamical behaviors of functionally graded material shallow shells with geometrical imperfections are studied in this paper. The material properties are graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents of the material. The motion, stability and compatibility equations of these structures are derived using the classical shell theory. The non-linear equations are solved by the Newmark's numerical integration method. The non-linear transient responses of cylindrical and doubly-curved shallow shells subjected to excited external forces are obtained and the dynamic critical buckling loads are evaluated based on the displacement responses using the criterion suggested by Budiansky and Roth. Obtained results show the essential influence of characteristics of functionally graded materials on the dynamical behaviors of shells.
Inverse kinematic and dynamic analysis of redundant measuring manipulator BKHN-MCX-04
Authors: Khang Nguyen Van , Dien Nguyen Phong , Vinh Nguyen Van , Nam Tran Hoang
Published: September 2014

This paper deals with the problem of inverse kinematics and dynamics of a measuring manipulator with kinematic redundancy which was designed and manufactured at Hanoi University of Technology for measuring the geometric tolerance of surfaces of machining components. A comparison between the calculation result and the experimental measurement is also presented.
Static analysis of laminated and sandwich composite plates based on simple refined higher-order displacement theory
Authors: Tu Tran Minh
Published: September 2014

A simple refined higher-order displacement theory is used for the static analysis of laminated and sandwich plates. Both analytical and finite element solutions are developed. Numerical examples of laminated and sandwich plates are given for different thickness ratios, length-to-thickness ratios to illustrate the accuracy of the present formulation by comparing the present results with results already available in the literature.
Finite element modelling and experimental study on static deflection and vibration of piezoelectric composite plates
Authors: Thinh Tran Ich , Ngoc Le Kim
Published: September 2014

A finite-element model based on the First-Order Shear Deformation Theory is developed for the static flexural shape and vibration control of a glass fibre/polyester composite plate bonded piezoelectric actuator and sensor patches. The piezoelectric's mass and stiffness are taken into account in the present model. A simple negative velocity feedback control algorithm coupling direct and converse piezoelectric effects are used to actively control the dynamic response of an integrated structure through a closed control loop. The static analysis and active vibration suppression control of a cantilever composite plate are performed as a numerical example to validate the proposed model. The Newmark-\(\beta\) method is used in the numerical simulation to calculate the dynamic response of the piezolaminated composite plate. The numerical results are presented with discussion and in good agreement with carried out experiments.
Velocity of long bubbles transported by a liquid in horizontal channel
Authors: Hien Ha Ngoc , Fabre Jean
Published: September 2014

The influence of flowing liquid on the motion of long bubbles in horizontal channel is studied theoretically. The method of Benjamin (1968) is extended to the case of moving liquid: the liquid is inviscid, the surface tension is ignored and the liquid motion at infinity is characterized its velocity profile. The exact solutions for the bubble velocity and the liquid film thickness are given under an integral form. An approximate analytical solution can be found when the mean liquid velocity is weak enough versus the drift velocity. Two cases are investigated: the Couette flow and the Poiseuille flow. At first order, the two cases lead to identical solutions. The influence of the velocity distribution appears only at the second order.
Non-linear vibration of functionally graded shallow spherical shells
Authors: Bich Dao Huy , Hoa Le Kha
Published: September 2014

The present paper deals with the non-linear vibration of functionally graded shallow spherical shells. The properties of shell material are graded in the thickness direction according to the power law distribution in terms of volume fractions of the material constituents. In the derived governing equations geometric non-linearity in all strain-displacement relations of the shell is considered. From the deformation compatibility equation and the motion equation a system of partial differential equations for stress function and deflection of shell is obtained. The Galerkin method and Runge-Kutta method are used for dynamical analysis of shells to give expressions of natural frequencies and non-linear dynamic responses. Numerical results show the essential influence of characteristics of functionally graded materials and dimension ratios on the dynamical behaviors of shells.
Optimal fuzzy control using hedge algebras of a damped elastic jointed inverted pendulum
Authors: Le Bui Hai , Trung Tran Duc , Lan Vu Nhu
Published: September 2014

In this paper, three controllers including OFCHA (optimal fuzzy control using hedge algebras-HAs), FCHA (fuzzy control using HAs) and CFC (conventional fuzzy control) are designed. Our attention is paid to the stability in the vertical position of a damped-elastic-jointed inverted pendulum subjected to a time-periodic follower force. Different values of the pendulum length are considered. Simulation results are exposed to illustrate the effect of OFCHA in comparison with FCHA and CFC.
A 6DOF super element for nonlinear analysis of composite frames with partial interaction and semi-rigid connections
Authors: Bao Nghi Le Luong , Cong Thanh Bui
Published: September 2014

This paper presents a displacement-based finite element formulation for nonlinear analysis of steel - concrete composite planar frames subjected to combined action of gravity and lateral loads. A 6DOF super element is proposed for modeling composite beam, allowing for partial interaction between the steel beam and the concrete slab, semi-rigid nature of beam to column composite connection and material nonlinearity. The load control method and the displacement control method are utilized for tracing the structural equilibrium paths, and the direct method is utilized for solving the nonlinear problem. Numerical examples, concerning a two-span continuous composite beam, a portal composite frame and a six-storey composite frame, are performed. The results are compared with experience data or theoretical results from other studies and are discussed for influences of the factors mentioned above on behaviour of composite beams and composite frames.
Cast3M implementation of the extended finite element method for cohesive crack
Authors: Giang Nguyen Truong , Nhu Ngo Huong
Published: September 2014

In this paper, the finite element for cohesive crack for quasi-brittle materials is constructed by the displacement discontinuities in the element. The algorithm of construction and procedures for involving this finite element into code Cast3M are presented. The numerical calculations in fracture mechanics are presented to demonstrate the benefits of the proposed implementation.
Finite element simulation of strain localization in inelastic solids by energy relaxation
Authors: Trinh B. T. , Hackl K.
Published: September 2014

A new approach for the treatment of strain localization in inelastic material is proposed. It is based on energy minimization principles associated with micro-structure developments. Shear bands are treated as micro-shearing of rank-one laminates.  It is assumed that the thickness of the shear band represented by its volume fraction tends to zero, and the energy inside the shear band is a function of the norm of the strain field. The existence of shear bands in the structure leads to an ill-posed problem which can be solved by means of energy relaxation. The performance of the proposed concept is demonstrated through numerical simulation of tension test under plane strain conditions. Numerical results show that mesh sensitivity can be completely removed.
Generalized continuum overall modelling of periodic composite structures
Authors: Trinh Duy Khanh , Forest Samuel
Published: September 2014

Classical homogenization methods fail to reproduce the overall response of composite structures when macroscopic strain gradients become significant. Generalized continuum models like Cosserat, strain gradient and micromorphic media, can be used to enhance the overall description of heterogeneous materials when the hypothesis of scale separation is not fulfilled. We show in the present work how the higher order elasticity moduli can be identified from suitable loading conditions applied to the unit cell of a periodic composite. The obtained homogeneous substitution generalized continuum is used then to predict the response of a composite structure subjected to various loading conditions. Reference finite element computations are performed on the structure taking all the heterogeneities into account. The overall substitution medium is shown to provide improved predictions compared to standard homogenization. In particular the additional boundary conditions required by generalized continua makes it possible to better represent the clamping conditions on the real structure.
About the choice of a plastic-like model for shape memory alloys
Authors: Lexcellent C. , Laydi R. M.
Published: September 2014

The aim of this paper is to examine the impact of the choice of plasticity theory-inspired model in the prediction of the shape of phase transformation domains. In this field a comparison is made between Huber-Von Mises based model and an another integrating the non-symmetry between tension and compression.  The yield surface of phase transformation initiation for a homogeneous body under proportional biaxial loading is discussed. A transport of these surfaces in the space of the "effective transformation strain of martensite tensor" is given.
Standard gradient models and crack simulation
Authors: Son Nguyen Quoc , Giang Nguyen Truong
Published: September 2014

The standard gradient models have been intensively studied in the literature, cf. Fremond (1985) or Gurtin (1991) for various applications in plasticity, damage mechanics and phase change analysis. The governing equations for a solid have been introduced essentially from an extended version of the virtual equation. It is shown here first that these equations can also be derived from the formalism of energy and dissipation potentials and appear as a generalized Biot equation for the solid. In this spirit, the governing equations for higher gradient models can be straightforwardly given. The interest of gradient models is then discussed in the context of damage mechanics and crack simulation. The phenomenon of strain localization in a time-dependent or time-independent process of damage is explored as a convenient numerical method to simulate the propagation of cracks, in relation with some recent works of theliterature, cf. Bourdin & Marigo [3], Lorentz & al  [5], Henry & al [12].
Homogenization of an interface highly oscillating between two concentric ellipses
Authors: Tung Do Xuan , Vinh Pham Chi , Tung Nguyen Kim
Published: September 2014

The main purpose of this paper is to find the homogenized equation and the associate continuity conditions in the explicit form of a boundary-value problem in a two-dimensional domain with an interface oscillating rapidly between two concentric ellipses. This boundary-value problem originates from various problems in practical applications. By the homogenization method and following the technique presented recently by Vinh and Tung [P. C. Vinh and D. X. Tung, Mech. Res.Comm. 37 (2010), 285-288; P. C. Vinh, D. X. Tung, ASME J. Appl. Mech., 78 (2011), 041014-1;  P. C. Vinh and D. X. Tung, Acta Mech. 218 (2011), 333-348], the homogenized equation and the associate continuity conditions in the explicit form are derived.
Solving nonlinear stability problem of imperfect functionally graded circular cylindrical shells under axial compression by Galerkin's method
Authors: Dung Dao Van , Hoa Le Kha
Published: September 2014

This paper presents an analytical approach to analyze the nonlinear stability of thin closed circular cylindrical shells under axial compression with material properties varying smoothly along the thickness in the power and exponential distribution laws. Equilibrium and compatibility equations are obtained by using Donnel shell theory taking into account the geometrical nonlinearity in von Karman and initial geometrical imperfection.  Equations to find the critical load and the load-deflection curve are established by Galerkin's method. Effects of buckling modes, of imperfection, of dimensional parameters and of volume fraction indexes to buckling loads and postbuckling load-deflection curves of cylindrical shells are investigated. In case of perfect cylindrical shell, the present results coincide with the ones of the paper  [13] which were solved by Ritz energy method.
Calculation of nonlinear vibrations of piecewise-linear systems using the shooting method
Authors: Khang Nguyen Van , Cuong Hoang Manh , Minh Tuan Nguyen Thai
Published: September 2014

In this paper, an explicit formulation of the shooting scheme for computation of multiple periodic attractors of a harmonically excited oscillator which is asymmetric with both stiffness and viscous damping piecewise linearities is derived. The numerical simulation by the shooting method is compared with that by the incremental harmonic balance method (IHB method), which shows that the shooting method is in many respects distinctively advantageous over the incremental harmonic balance method.
Calculating the aerodynamics of vertical axis wind turbines
Authors: Ngoc Hoang Thi Bich
Published: September 2014

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.
Isogeometric analysis of two-dimensional piezoelectric structures
Authors: Truong Hoang H. , Thai Chien H. , Nguyen-Xuan H.
Published: September 2014

The isogeometric analysis (IGA) that integrates Computer Aided Design(CAD) and Computer Aided Engineering (CAE) is found so far the effectively numerical tool for the analysis of a variety of practical problems. In this paper, we develop further the NURBS based isogeometric analysis framework for piezoelectric structures.The method employs the NURBS basis functions in both geometry representation and analysis. The main advantages of the present method are capable of handling the exactgeometry of conic sections and making the flexibility of refinement and degree elevationwith an arbitrary continuity of basic functions. These features results in high accuracy of approximate solutions for practical applications, especially piezoelectric problems. Three numerical examples are provided to validate excellent performance of the present method.
On two-field NURBS-based isogeometric formulation for incompressible media problems
Authors: Loc Tran Vinh , Chien Thai Hoang , Hung Nguyen Xuan
Published: September 2014

This paper presents u-p mixed formulation relied on the framework of NURBS-based Isogeometric approach (IgA) for incompressible problems. In mixed method, displacement (velocity) field is approximated using NURBS basis functions with one order higher than that of pressure one. Being different from the standard FEM, the IgA allows to increase (or decrease) easily the order and continuous derivative of interpolated functions. As a result, a family of NURBS elements, which satisfies the inf-supcondition, is obtained. Benchmark examples are given to validate the excellent performance of the method.
Stable control of networked robot subject to communication delay, packet loss, and out-of-order delivery
Authors: Phung Manh Duong , Tran Thuan Hoang , Tran Quang Vinh
Published: September 2014

Stabilization control of networked robot system faces uncertain factors caused by the network. Our approach for this problem consists of two steps. First, the Lyapunov stability theory is employed to derive control laws that stabilize the non-networked robot system. Those control laws are then extended to the networked robot system by implementing a predictive filter between the sensor and controller. The filter compensates influences of the network to acquire accurate estimate of the system state and consequently ensures the convergence of the control laws. The optimality of the filter in term of minimizing the mean square error is theoretically proven. Many simulations and experiments have been conducted. The result confirmed the validity of the proposed approach.
Umbrales para la determinación de la brecha digital: comparativa entre regiones desarrolladas
Authors: Mendoza-Ruano Juan-José , Caldera-Serrano Jorge
Published: September 2014

Este trabajo tiene como objetivo principal establecer una escala porcentual que sirva de base metodológica para determinar la existencia o no de brecha digital entre regiones tecnológicamente desarrolladas. Una vez analizada la literatura científica observamos un claro déficit al no contar con una base estudiada que determine bajo qué parámetros se puede hablar de Brecha Digital al realizar la comparativas entre zonas. Además, contextualizamos el tema con una breve descripción de los conceptos básicos para el estudio, como son el de Sociedad de la Información, y en mucha mayor profundidad, la Brecha Digital. Las escalas planteadas son válidas para zonas geográficas de un nivel desarrollado en tecnologías de la información y la comunicación, no siendo un trabajo válido para zonas subdesarrolladas o en vías de transformación tecnológica. Se plantea por tanto cuatro niveles de brecha digital que corresponden con las siguientes escalas porcentuales: 1%-5%, 6%-10%, 11%-15%, más de 16%, respectivamente.
Actitudes y percepciones de los docentes universitarios en el proceso de adopción de una innovación: la iniciativa OpenCourseWare en la Universidad de Valencia, España
Authors: Margaix-Fontestad Lourdes , González-Teruel Aurora , Abad-García Maria Francisca
Published: September 2014

El proyecto OpenCourseWare, repositorio de recursos educativos en abierto, se inició en la Universidad de Valencia en 2008 y en 2009, sólo incluía 10 asignaturas, ninguna de ellas del área de Ciencias de la Salud. El objetivo de este trabajo es investigar las actitudes de los docentes de esta área así como sus percepciones con relación a este repositorio para determinar cuáles son las estrategias necesarias para extender su uso. Se parte de la teoría de la difusión de las innovaciones de Rogers y de un enfoque cualitativo a través del muestreo teórico, entrevistas semiestructuradas y codificación abierta. Los resultados indican la existencia de dos grandes grupos de profesores. Los adoptantes tempranos con una predisposición alta a participar en la iniciativa y con una percepción positiva de sus atributos y los mainstream o corriente principal más reacios a participar y con una percepción negativa respecto a alguno de sus atributos. La identificación de las características de estos dos grandes grupos marca las líneas de acción y de investigación futura en el ámbito del marketing y difusión, formación, sensibilización y motivación para extender el uso del OpenCourseWare.
Bibliometric factors associated with h-index of Peruvian researchers with publications indexed on Web of Science and Scopus databases
Authors: Vílchez-Román Carlos
Published: September 2014

The objective of this article is: a) to identify Peruvian researchers with high, medium and low impact factor according to Web of Science and Scopus databases; b) to identify the bibliometric factor with the highest influence on h-index of Peruvian esearchers; c) to compare h-index between Web of Science and Scopus, at an individual and institutional level. Data were collected from Web of Science and Scopus (189 Peruvian researchers, 28 institutions on Web of Science and 33 on Scopus), between September 1823, 2013. Then, institutional registries were created and linear regression analysis with stepwise procedure was run to identify bibliometric factors with higher influence on the h-index of Peruvian researchers. Web of Science and Scopus showed interesting simmilarities in the h-index of Peruvian academic institutions. At individual level, documents indexed in citation database had the highest influence on the h-index. Regression model identified bibliometric factors with higher influence on the h-index of Peruvian researchers, however further large scale studies are needed to improve external validity.
La comunicación científica en Uruguay: estudio de las publicaciones de los investigadores activos del Sistema Nacional de Investigadores (2009-2010)
Authors: Picco Paola , Aguirre-Ligüera Natalia , Maldini Juan , Simón Lucía , Petroccelli Patricia , Fontans Exequiel , Fager José , Gladys Ceretta María
Published: September 2014

Se estudia el fenómeno de la comunicación científica en Uruguay considerando las publicaciones declaradas en los Currícula Vitae por parte de los investigadores que integran el Sistema Nacional de Investigadores de la Agencia Nacional de Investigación e Innovación de Uruguay. Se construye una base de datos ad-hoc, en la que se registran los datos relativos a las siguientes variables: área de conocimiento, tipo de publicación, tipo de responsabilidad, idioma, lugar de publicación, soporte, arbitraje e indización. El análisis de los datos se realiza a partir de una aproximación cuantitativa, con métodos estadísticos descriptivos. Los datos se procesan mediante un software para análisis estadístico. En consonancia con la literatura se encuentra que los patrones de comunicación varían de acuerdo al área de conocimiento. Se concluye que los Currícula Vitae, a pesar de sus limitaciones, son una fuente rica para abordar el estudio de la producción científica en su conjunto, y que estos trabajos son complementarios a los estudios bibliométricos realizados a partir de bases de datos internacionales que permiten estudiar otros aspectos.
Taxonomias navegacionais em sítios de comércio eletrônico: critérios para avaliação
Authors: Cavalcante Raphael da Silva , Bräscher Marisa
Published: September 2014

Este artigo apresenta o resultado da pesquisa de mestrado que teve como objetivo propor e validar um conjunto de critérios para a avaliação de taxonomias navegacionais utilizadas em sítios de comércio eletrônico. A escolha do ambiente de aplicação considera o uso difundido das taxonomias nos sítios referidos. Em seu percurso metodológico, a pesquisa apresenta revisão de literatura, na qual se discutem aspectos teóricos acerca de taxonomias e comércio eletrônico. Dessa forma, são definidos dois critérios de avaliação: a Comunicabilidade e a Organização. A amostra selecionada para a aplicação dos critérios compõe-se de cinco lojas virtuais. O resultado da avaliação revela-se heterogêneo, com lojas classificadas com menções entre regular e excelente. Finalmente, os insumos obtidos são considerados consistentes e os critérios são validados. Reconhece-se a construção de taxonomias como uma atividade subjetiva, mas defende que recomendações mínimas devem ser consideradas.
Fontes de informação na Web: apropriação, uso e disseminação da informação étnico-racial no movimento negro da Paraíba
Authors: Silva Leyde Klebia Rodrigues da , Aquino Mirian de Albuquerque
Published: September 2014

O artigo analisa como o Movimento Negro do Estado da Paraíba faz a apropriação das fontes de informação na Web e usa-as na perspectiva de disseminação da informação étnico-racial. As fontes de informação podem ser utilizadas como um canal de disseminação da informação étnico-racial para auxiliar os grupos sociais e etnicamente invisibilizados na atual sociedade da informação-conhecimento-aprendizagem-comunicação, em cujo local o preconceito, a discriminação e o racismo fazem parte do cotidiano dos sujeitos. O universo da pesquisa foi o Movimento Negro Organizado da Paraíba, e os participantes foram quatro ativistas desse movimento: o Núcleo de Estudantes Negras e Negros da Universidade Federal da Paraíba e a Organização de Mulheres Negras na Paraíba. Os resultados mostraram que a ferramenta mais utilizada para veicular a informação é o e-mail. Conclui-se que a apropriação das fontes de informação já utilizadas deve servir como um espaço virtual de armazenamento da informação produzida.
Adaptação transcultural do Teste de Conhecimento Emocional: avaliação neuropsicológica das emoções
Authors: Andrade Nara Côrtes , Abreu Neander , Menezes Igor , Mello Cláudia Berlim de , Duran Victor Riccio , Moreira Narena de Alencar
Published: September 2014

As emoções desempenham um papel central nas relações das crianças e déficits na compreensão de emoções têm sido associados a diversos transtornos neuropsiquiátricos na infância. Entretanto, verifica-se uma escassez de instrumentos psicológicos disponíveis no Brasil que avaliem esta habilidade. O presente estudo teve por objetivo adaptar transculturalmente o Teste de Conhecimento Emocional (EMT). O instrumento original foi traduzido por uma equipe de pesquisadores bilíngues e posteriormente retraduzido para o inglês. As versões preliminares foram julgadas pelos autores do instrumento e por juízes brasileiros especialistas. A versão final foi aplicada em uma amostra de 50 crianças entre três e seis anos de idade e respondida por nove juízes de três estados brasileiros. Os resultados mostram uma boa equivalência semântica, além de bons níveis de concordância quanto às respostas (κ= 0,88, Z=95,2, p<0,001). A versão final do EMT mostrou-se adequada e satisfatória.
Andarilhos de estrada e os serviços sociais de assistência
Authors: Nascimento Eurípedes Costa do , Justo José Sterza
Published: September 2014

Este artigo tem por finalidade discutir os serviços assistenciais que algumas instituições oferecem aos andarilhos de estrada, procurando refletir, também, o que eles representam no contexto social contemporâneo. Participaram desta pesquisa quatro dirigentes de instituições assistenciais no Estado de São Paulo, por meio de um roteiro de entrevista semi-estruturado. Os dados foram analisados a partir da técnica de análise de conteúdo. Os relatos mostraram que os serviços oferecidos se estruturam de acordo com os interesses políticos do Estado na administração e fixação desses sujeitos para os territórios da marginalidade social onde o saber médico exerce uma função estratégica sob essas subjetividades. Os resultados indicam a necessidade de ampliar o debate em torno das políticas assistenciais a fim de se implementar um serviço desvinculado da tendência homogeneizadora do saber médico, levando em consideração os próprios indivíduos portadores de história e singularidade sem a incidência da normalização.
Atribuições de causalidade para o desempenho escolar e resiliência em estudantes
Authors: Garcia Natália Rodovalho , Boruchovitch Evely
Published: September 2014

Este artigo tem como objetivo analisar as atribuições de causalidade para o sucesso e para o fracasso escolar e a resiliência em estudantes do ensino fundamental, bem como verificar se existem relações entre esses construtos na amostra. Participaram do estudo 275 alunos do 5º ao 9º ano, de ambos os sexos, de uma escola pública de uma cidade do interior do Estado de Minas Gerais. Os dados foram coletados por meio de duas escalas do tipo likert e analisados de acordo com os procedimentos da estatística descritiva e inferencial. Os estudantes relataram atribuir causas internas e controláveis ao desempenho escolar, para ambas as situações de sucesso e fracasso, e reportaram as características principais da resiliência. Foi encontrada correlação significante, positiva e de magnitude forte, entre as atribuições de causalidade e a resiliência. Os resultados são discutidos em termos de suas implicações educacionais.