Mechanical properties of phenine nanotubes

Phenine Nanotubes (PhNT) are cylinder-shaped molecules synthetized from 1,3,5-trisubstituted benzene ring building blocks that can form tubular segments of different sizes. Small nanotube segments have been recently synthetized, and efforts are being made to increase the nanotubes’ length by adding more “phenine” units. To the authors’ best knowledge, a complete characterization of the mechanical properties of these nanotubes has not yet been accomplished. In this work, Reax and AIREBO forcefields were used to model armchair and zigzag PhNTs and Molecular Dynamics simulations were employed to determine their mechanical properties for tensile, compressive, bending and twisting loadings. It was found that PhNTs have a much lower Young’s modulus (about 30%) and tensile strengths (about 45%) than carbon nanotubes (CNTs), but can endure longer tensile strains without breaking apart. Although possessing a lower bending and twisting stiffness than CNTs, PhNT have highly flexible sidewalls due to their superior porosity, and therefore can withstand higher angles of twist and angles of bend without breaking bonds. This extra flexibility; extended porosity; possibility for heteroatom doping and reasonable strength, make PhNTs very promising candidates for a wide range of applications, such as sensing, ionic transistors or molecular sieving. Finally, a brief study on the application of elastic continuum shell formulas to predict the critical stress (compression), critical moment (bending) and critical torque (twisting) is also presented

Aplicação experimental de um diferenciador semântico ao teste de Rorschach

Inexistent

Instrumentação axial e radial em ensaios triaxiais no domínio das pequenas deformações

A maior parte das deformações dos solos ocorre para níveis de deformação entre 0.01 % a 0.5 %, tornando-se fundamental uma correcta caracterização do comportamento dos solos e geomateriais para este domínio de pequenas deformação. Para a determinação do comportamento geotécnico nestes domínios, é indispensável nos ensaios triaxiais a utilização de instrumentação local para a eliminação de erros derivados do efeito de confinamento do provete, de fenómenos de flexão e deformação do sistema de ensaio. Uma técnica de instrumentação eficaz e de baixo custo consiste na utilização de Local Deformation Transducer (LDT). Neste artigo apresenta-se a sua eficiência na monitorização de ensaios triaxiais monotónicos a trajectória controlada, e cíclicos, ilustrando-se métodos para o registo da deformação radia. São ainda ilustrados casos de estudo com o intuito de validar a sua eficiência, nomeadamente ensaios em trajectória de tensões controladas e ensaios cíclicos

The cyclic triaxial test as tool to quantify coarse non-conventional materials response

Sustainable waste management requires efficient dealing to protect landfill and reduce waste deposits. For that it becomes necessary to improve material characterization, using performance based tests, to estimate waste reuse as construction material. Several mechanical tests exist which make possible to use numerical tools to estimate reversible and irreversible behaviour of non-conventional coarse material, as industrial waste. From the available tests, the large-scale cyclic triaxial test is commonly used since it is the simple one to implement and allows the study of the irreversible behaviour, an import factor for materials to be used in roadway and railway infrastructures. The large-scale cyclic triaxial test is an equipment that exists on several important laboratories, in Europe, USA and Asia. This paper describes a large cyclic triaxial test facility developed at Centre for Waste Valorisation (Campus of University of Minho), able to study coarse aggregates/waste materials with grain size particles up to 50 mm

Precision triaxial equipment for the evaluation of the elastic behavior of soils

Samples of a sandy soil reconstituted by Proctor compaction were investigated under different isotropic and anisotropic stress paths for different initial stress states in the p-q space using a triaxial apparatus developed for this purpose. The equipment uses a triaxial cell with sample instrumentation for accurate measurements of the stress and strain states. The tendencies of the limit of the elastic domain were analyzed. Several initial stress states and stress paths were investigate in order to quantify key tendencies. Results show that the limit of the elastic domain of the studied soil depends on the initial stress state and on the applied stress path.University of Illinois at Urbana-Champaig, Illinois Center for Transportation, Center of Excellence for Airport Pavement Research, University of Illinois Railroad Engineering Program, Illinois Department of Transportation, U.S. Department of Transportation, Federal Aviation Administration, Association of American Railroads, Transportation Research Board, American Society of Civil Engineer

Selecting a Software Tool for ITIL using a Multiple Criteria Decision Analysis Approach

The opportunity to improve service quality using ITIL has led many organizations to invest in the implementation of this framework. Selecting a software tool for ITIL is still one of the most difficult decisions due to lack of meaningful evaluation criteria and guidelines to help on that decision, making this, one of the most important and error-triggering steps in this way. A multi-criteria value model to evaluate software tools for ITIL using a multi-criteria decision analysis (MCDA) approach based on MACBETH is then proposed to address this problem. A focus on the functionality of the tool to extract criteria from the literature to assess four representative software solutions for ITIL in the market is made along with its demonstration in a company of the bank sector. Finally, using Moody and Shanks Framework, the proposed method is evaluated showing that is suitable for evaluating software tools for ITIL

Critérios e prioridades para a gestão financeira no Serviço Nacional de Saúde

Introdução: O Serviço Nacional de Saúde tem sofrido nos últimos 30 anos fortes críticas na sua gestão financeira - para muitos tem havido uma continuada redução orçamental ou um claro desinvestimento financeiro (e humano) levando a que se verificasse uma degradação da qualidade do serviço prestado. Ora, a necessidade de reduzir os gastos com a saúde levanta questões sobre medidas efetivas de contenção da despesa. O estabelecimento de prioridades em saúde deve ser considerado nas opções estratégicas que garantam a sustentabilidade. A priorização deve ser explícita e sistemática e a perspetiva da população deve ser considerada. O objetivo desta dissertação é o perceber a perspetiva da população no que se refere ao racionamento e ao estabelecimento de grupos prioritários na saúde Metodologia: Com base num paradigma positivista foi realizado um estudo descritivocorrelacional e transversal. A população em estudo são indivíduos portugueses com idade igual ou superior a 18 anos. A amostra foi aleatória incluindo 400 indivíduos. Resultados: Da amostra utilizada, verificou-se que em geral os inquiridos discordam da existência de um limite de gastos no SNS e consideram como meios de financiamento adicional o aumento das receitas com a lotaria e os jogos da sorte bem como dos impostos sobre o tabaco e o álcool. A sua perceção é de que os profissionais de saúde são o grupo profissional mais influente na forma como o dinheiro é gasto no SNS. Concordam com a definição de grupos prioritários, que seriam os idosos e as crianças. Sobre as áreas prioritárias elegem as relacionadas com a melhoria dos resultados em saúde tais como, a prestação de cuidados de saúde eficientes, aumentar o número de anos de vida com qualidade, e redução das desigualdades no acesso. Conclusões: O estabelecimento de prioridades na saúde é complexo e deve incorporar todas as ações de clarificação e validação das decisões. Este processo deve sempre englobar todos os atores sociais com o cidadão no centro do modelo de prestação de cuidados de saúde.Introduction: In the last 30 years, the National Health Service has suffered strong criticism in its financial management - for many there has been a continuous reduction in budget or a clear financial (and human) disinvestment, leading to a degradation of the quality of the service provided. The need to reduce health spending raises questions about effective measures to contain expenditure. The establishment of health priorities should be considered in the strategic options that guarantee sustainability. The prioritization must be explicit and systematic and the population perspective must be considered. The objective of this dissertation is to perceive the population's perspective regarding rationing and the establishment of priority health groups. Methodology: Based on a positivist paradigm, a descriptive-correlational and crosssectional study was carried out. The study population are Portuguese individuals aged 18 years or over. The sample was random including 400 individuals. Results: From the sample used, it was found that in general the respondents disagree about the existence of a spending limit in the NHS and accept as an additional means of financing the increase in lottery and gambling revenues as well as taxes on tobacco and alcohol. The respondent’s perception is that health professionals are the most influential professional group in the way money is spent in the NHS. They agree on the definition of priority groups, that would be the elderly and the children. Priority areas include those related to improving health outcomes such as the provision of efficient health care, increasing the number of quality years of life, and reducing inequalities in the access to it. Conclusions: The establishment of priorities in health is complex and should incorporate all actions for clarification and validation of decisions. This process should always involve all social actors with the citizen at the center of the model of health care delivery

Impact of the Fourth Industrial Revolution on the Health Sector: A Qualitative Study

Objectives: The Fourth Industrial Revolution is changing the way health is understood, transforming the methods of treatment and diagnosis as well as the relationship between health professionals and patients and altering the management and organization of health systems. The main objective of this study was to explore the impact that the Fourth Industrial Revolution is having on the health sector. Methods: Conducting interviews consisting of four questions with 10 professionals who had experience working in the health sector to gain their insights and to obtain information to meet the general objective of the study as well as its specific objectives. Results: From the analysis of the respondents’ responses, it was possible to create five dimensions developed by the topics most addressed by respondents, namely, impact on healthcare efficiency and effectiveness, impact on government action, impact on human resources, impact on health system organization, and financial impact on the health sector. Conclusions: Although the Fourth Industrial Revolution is still at an early stage, it has been concluded that it is having a major positive impact on the health sector. For the effective and efficient implementation of these disruptive technologies, a global interaction between governments, health professionals, stakeholders, and society is essential to make this change possible.info:eu-repo/semantics/publishedVersio

A Computer Tool for 3D Shape Recovery of Fruits

Characterizing a fruit’s mechanical behavior is an important step towards reducing economic losses due to bruising. Several 3D scanning technologies allow to obtain the external geometry of a fruit, but no easily accessible tools exist for the acquisition of the geometry of internal structures such as the core. We propose a low-cost destructive method for tomographic reconstruction of a fruit from scanned slices. A method for overcoming the difficulties in registering the different images is also presented.info:eu-repo/semantics/publishedVersio

Study on guardrail post behavior located on organic soil using simplified experimental and numerical methods

For the purpose of road safety, it is vital to reduce the severity of road accidents and increase safety around the roadway area by deploying guardrails. In case of a car crash, a guardrail post must be deformable so that such restraint is not too abrupt due to the occupant’s sensitivity. Soil type influences on the guardrail post behavior have been a somewhat unfounded variable due to the high soil heterogeneity and challenging interpretation of its real implications on the safety of guardrail systems. Since little attention is concentrated on evaluating the guardrail post behavior through simplified procedures, this article aims to provide a simplified experimental and numerical approach to study the behavior of guardrail posts located on organic soil. Results of laboratory and in-situ tests indicated that guardrail posts behavior located on organic soil depends on section orientation, driving depth, and loading speed. To confirm and compare the in-situ tests, simplified numerical simulations through Plaxis 3D software were carried out, and data from numerical modeling approved the accuracy of in-situ results.The authors acknowledge the financial support by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020; and ANI through national funds (Portugal 2020), under project “BARROD - Barreiras de Segurança Rodoviária”, reference 33497