Multibody modelling of a TB31 and a TB32 crash test with vertical portable concrete barriers: model verification and sensitivity analysis.

In this article the multibody simulation software package MADYMO for analysing and optimizing occupant safety design was used to model crash tests for Normal Containment barriers in accordance with EN 1317. The verification process was carried out by simulating a TB31 and a TB32 crash test performed on vertical portable concrete barriers and by comparing the numerical results to those obtained experimentally. The same modelling approach was applied to both tests to evaluate the predictive capacity of the modelling at two different impact speeds. A sensitivity analysis of the vehicle stiffness was also carried out. The capacity to predict all of the principal EN1317 criteria was assessed for the first time: the acceleration severity index, the theoretical head impact velocity, the barrier working width and the vehicle exit box. Results showed a maximum error of 6% for the acceleration severity index and 21% for theoretical head impact velocity for the numerical simulation in comparison to the recorded data. The exit box position was predicted with a maximum error of 4°. For the working width, a large percentage difference was observed for test TB31 due to the small absolute value of the barrier deflection but the results were well within the limit value from the standard for both tests. The sensitivity analysis showed the robustness of the modelling with respect to contact stiffness increase of ±20% and ±40%. This is the first multibody model of portable concrete barriers that can reproduce not only the acceleration severity index but all the test criteria of EN 1317 and is therefore a valuable tool for new product development and for injury biomechanics research.

Estimation of the hydraulic conductivity of soils improved with vertical drains

In this study, some limitations associated with modeling the hydraulic conductivity of soil improved with vertical drains are discussed. In addition, some limitations of conventional methodologies for deducing the hydraulic conductivity from oedometer or Rowe cell tests are investigated. An alternative approach for estimating the hydraulic conductivity in soils improved by vertical drains is discussed. This methodology will allow for simpler finite element modeling of consolidation due to vertical drains. The effectiveness of this technique has been demonstrated using a field study.

Evaluation of infilled frames: an updated in-plane-stiffness macro-model considering the effects of vertical loads

The influence of masonry infills on the in-plane behaviour of RC framed structures is a central topic in the seismic evaluation and retrofitting of existing buildings. Many models in the literature use an equivalent strut member in order to represent the infill but, among the parameters influencing the equivalent strut behaviour, the effect of vertical loads acting on the frames is recognized but not quantified. Nevertheless a vertical load causes a non-negligible variation in the in-plane behaviour of infilled frames by influencing the effective volume of the infill. This results in a change in the stiffness and strength of the system. This paper presents an equivalent diagonal pin-jointed strut model taking into account the stiffening effect of vertical loads on the infill in the initial state. The in-plane stiffness of a range of infilled frames was evaluated using a finite element model of the frame-infill system and the cross-section of the strut equivalent to the infill was obtained for different levels of vertical loading by imposing the equivalence between the frame containing the infill and the frame containing the diagonal strut. In this way a law for identifying the equivalent strut width depending on the geometrical and mechanical characteristics of the infilled frame was generalized to consider the influence of vertical loads for use in the practical applications. The strategy presented, limited to the initial stiffness of infilled frames, is preparatory to the definition of complete non-linear cyclic laws for the equivalent strut.

The Vertical Distribution and Evolution of Slam Pressure on an Oscillating Wave Surge Converter

The accurate definition of the extreme wave loads which act on offshore structures represents a significant challenge for design engineers and even with decades of empirical data to base designs upon there are still failures attributed to wave loading. The environmental conditions which cause these loads are infrequent and highly non-linear which means that they are not well understood or simple to describe. If the structure is large enough to affect the incident wave significantly further non-linear effects can influence the loading. Moreover if the structure is floating and excited by the wave field then its responses, which are also likely to be highly non-linear, must be included in the analysis. This makes the description of the loading on such a structure difficult to determine and the design codes will often suggest employing various tools including small scale experiments, numerical and analytical methods, as well as empirical data if available.
Wave Energy Converters (WECs) are a new class of offshore structure which pose new design challenges, lacking the design codes and empirical data found in other industries. These machines are located in highly exposed and energetic sites, designed to be excited by the waves and will be expected to withstand extreme conditions over their 25 year design life. One such WEC is being developed by Aquamarine Power Ltd and is called Oyster. Oyster is a buoyant flap which is hinged close to the seabed, in water depths of 10 to 15m, piercing the water surface. The flap is driven back and forth by the action of the waves and this mechanical energy is then converted to electricity.
It has been identified in previous experiments that Oyster is not only subject to wave impacts but it occasionally slams into the water surface with high angular velocity. This slamming effect has been identified as an extreme load case and work is ongoing to describe it in terms of the pressure exerted on the outer skin and the transfer of this short duration impulsive load through various parts of the structure.
This paper describes a series of 40th scale experiments undertaken to investigate the pressure on the face of the flap during the slamming event. A vertical array of pressure sensors are used to measure the pressure exerted on the flap. Characteristics of the slam pressure such as the rise time, magnitude, spatial distribution and temporal evolution are revealed. Similarities are drawn between this slamming phenomenon and the classical water entry problems, such as ship hull slamming. With this similitude identified, common analytical tools are used to predict the slam pressure which is compared to that measured in the experiment.

FRENKEL-KONTOROVA DOMAIN-WALL PHASE-TRANSITIONS IN AN ADSORBED LAYER - POTASSIUM ON CO(10(1)OVER-BAR-0)

As the potassium fractional coverage of a cobalt {1010BAR} surface is increased over the range 0.2 to 0.6 monolayer the adlayer passes through a series of phase transitions. A commensurate phase is formed at exactly 0.5 monolayer, and corresponds to adatoms bonded in high-symmetry hollow sites on the unreconstructed cobalt surface, with an effective adatom radius lying between the ionic and covalent radii of potassium. A detailed structural study shows that the structural transitions can be characterised within a one-dimensional Frenkel-Kontorova model, with small lateral displacements of adatoms away from hollow sites in the low and high coverage phases. The low coverage phases progress from a distributed vacancy structure to a low density domain-wall structure; while the high coverage phase formed above half a monolayer is a high density asymmetric domain-wall structure.

High Strength Thermoplastic Bonding for Multi-channel, Multi-layer Lab-on-Chip Devices for Ocean and Environmental applications

A solvent-vapour thermoplastic bonding process is reported which provides high strength bonding of PMMA over a large area for multi-channel and multi-layer microfluidic devices with shallow high resolution channel features. The bond process utilises a low temperature vacuum thermal fusion step with prior exposure of the substrate to chloroform (CHCl3) vapour to reduce bond temperature to below the PMMA glass transition temperature. Peak tensile and shear bond strengths greater than 3 MPa were achieved for a typical channel depth reduction of 25 µm. The device-equivalent bond performance was evaluated for multiple layers and high resolution channel features using double-side and single-side exposure of the bonding pieces. A single-sided exposure process was achieved which is suited to multi-layer bonding with channel alignment at the expense of greater depth loss and a reduction in peak bond strength. However, leak and burst tests demonstrate bond integrity up to at least 10 bar channel pressure over the full substrate area of 100 mm x 100 mm. The inclusion of metal tracks within the bond resulted in no loss of performance. The vertical wall integrity between channels was found to be compromised by solvent permeation for wall thicknesses of 100 µm which has implications for high resolution serpentine structures. Bond strength is reduced considerably for multi-layer patterned substrates where features on each layer are not aligned, despite the presence of an intermediate blank substrate. Overall a high performance bond process has been developed that has the potential to meet the stringent specifications for lab-on-chip deployment in harsh environmental conditions for applications such as deep ocean profiling.

Analytical model for bar-end cover separation failure in RC beams strengthened with near-surface mounted FRP

The flexural performance of RC beams can be improved using the near-surface mounted (NSM) FRP strengthening technique. A likely failure mode of such FRP-strengthened RC beams is bar-end cover separation which involves the detachment of the NSM FRP reinforcement together with the concrete cover along the level of the steel tension reinforcement. This paper presents a new analytical strength model for this failure mode. The proposed strength model and two existing strength models for this failure mode are compared with test results to demonstrate the superior performance of the new analytical model.

BAR domains as sensors of membrane curvature:the amphiphysin BAR structure

The BAR (Bin/amphiphysin/Rvs) domain is the most conserved feature in amphiphysins from yeast to human and is also found in endophilins and nadrins. We solved the structure of the Drosophila amphiphysin BAR domain. It is a crescent-shaped dimer that binds preferentially to highly curved negatively charged membranes. With its N-terminal amphipathic helix and BAR domain (N-BAR), amphiphysin can drive membrane curvature in vitro and in vivo. The structure is similar to that of arfaptin2, which we find also binds and tubulates membranes. From this, we predict that BAR domains are in many protein families, including sorting nexins, centaurins, and oligophrenins. The universal and minimal BAR domain is a dimerization, membrane-binding, and curvature-sensing module.

Membrane fission is promoted by insertion of amphipathic helices and is restricted by crescent BAR domains

Shallow hydrophobic insertions and crescent-shaped BAR scaffolds promote membrane curvature. Here, we investigate membrane fission by shallow hydrophobic insertions quantitatively and mechanistically. We provide evidence that membrane insertion of the ENTH domain of epsin leads to liposome vesiculation, and that epsin is required for clathrin-coated vesicle budding in cells. We also show that BAR-domain scaffolds from endophilin, amphiphysin, GRAF, and β2-centaurin limit membrane fission driven by hydrophobic insertions. A quantitative assay for vesiculation reveals an antagonistic relationship between amphipathic helices and scaffolds of N-BAR domains in fission. The extent of vesiculation by these proteins and vesicle size depend on the number and length of amphipathic helices per BAR domain, in accord with theoretical considerations. This fission mechanism gives a new framework for understanding membrane scission in the absence of mechanoenzymes such as dynamin and suggests how Arf and Sar proteins work in vesicle scission.

Establishing the Evidence Bar for Molecular Diagnostics in Personalised Cancer Care

While personalised cancer medicine holds great promise, targeting therapies to the biological characteristics of patients is limited by the number of validated biomarkers currently available. The implementation of biomarkers has undergone many challenges with few biomarkers reaching cancer patients in the clinic. There have been many biomarkers that have been published and claimed to be therapeutically useful, but few become part of the clinical decision-making process due to technical, validation and market access issues. To reduce this attrition rate, there is a significant need for policy makers and reimbursement agencies to define specific evidence requirements for the introduction of biomarkers into clinical practice. Once these requirements are more clearly defined, in an analogous manner to pharmaceuticals, researchers and diagnostic companies can better focus their biomarker research and development on meeting these specific requirements, which should lead to the more rapid introduction of new molecular oncology tests for patient benefit.

Dual Classification Revisited: Rodney Needham and Vertical Asymmetry aboard Scottish Trawlers

Drawing on ethnographic data collected while working as a deckhand on two Scottish trawlers, this article analyses the spatialisation of social, religious and economic inequalities that marked relations between crew members while they hunted for prawns in the North Sea. Moreover, it explores these inequalities as a wider feature of life in Gamrie, Aberdeenshire, a Brethren and Presbyterian fishing village riven by disparities in wealth and religion. Inequalities identified by fishermen at sea mirrored those identified by residents onshore, resulting in fishing boats being experienced as small 'floating villages'. Drawing on the work of Rodney Needham, this article suggests that these asymmetries can be traced along a vertical axis, with greater to lesser wealth and religiosity moving from top/above to bottom/below. The article seeks to understand the presence and persistence of these hierarchies at sea and on land, by revisiting dual classification within anthropological theory.

Insucesso escolar: causas e consequências no contexto do Agrupamento Vertical de Ourique (período 1999/2000 a 2007/2008)

O presente estudo, de carácter quantitativo e qualitativo, assenta na temática do insucesso escolar. O mesmo foi orientado pela questão de partida que o perspectivou: “Quais as causas, consequências e dimensão do fenómeno do insucesso escolar nos alunos que iniciaram, em 1999/2000, a sua escolaridade, no concelho de Ourique? Baseados no quadro conceptual de um estudo de caso, seleccionámos uma “coorte” de alunos, que entrevistámos, com vista a inteirarmo-nos das experiências e situações reais que os conduziram a situações de insucesso escolar procurando dar resposta aos seguintes objectivos: 1) avaliar, quantitativamente, o insucesso escolar na população discente seleccionada; 2) identificar as, eventuais, causas do insucesso escolar verificado; 3) identificar as, eventuais, consequências do insucesso escolar verificado; 4) avaliar possíveis intervenções no sentido de mitigar o fenómeno do insucesso escolar. Para tal, analisámos o percurso escolar de um universo de 46 alunos, entre 1999/2000 e 2007/08, tendo verificado que 24 desses alunos vivenciaram episódios de insucesso escolar, ao longo do seu trajecto académico. Destes, entrevistámos 12 alunos, tendo essa abordagem possibilitado ir de encontro aos nossos objectivos. Através da análise e interpretação dos dados recolhidos, concluímos que: 1) a taxa de insucesso escolar é superior a 50%, na coorte de alunos que iniciaram a sua escolaridade, no ano lectivo 1999/00, no concelho de Ourique; 2) há uma forte participação dos pais e encarregados de educação nas vivências escolares dos alunos (80% do total da amostra); 3) o número médio de retenções, nos alunos com episódios de insucesso escolar, é de 1,5 retenções; 4) o 7.º ano de escolaridade é o ano em que se verifica um maior número de retenções, seguido do 4.º ano de escolaridade; 5) a maioria dos alunos (58,3%) encontra-se relativamente distante do seu meio familiar; 6) um número significativo de alunos com episódios de insucesso escolar (83,3%) referiu que recebe apoio da família; 7) a incapacidade individual foi a causa do insucesso escolar mais referida/inferida pelos entrevistados; 8) evidenciou-se que retenções precoces induzem a retenções posteriores; 9) a importância do 1.º Ciclo é relevante, quando os entrevistados indicam que a falta de apoio no 1.º Ciclo terá induzido a situações futuras de insucesso escolar. No final deste trabalho são efectuadas propostas que possam potenciar futuras investigações, nomeadamente de investigação acção, promovendo intervenção; ### Abstract: The schools failure: The causes of consequences in context the Agrupamento Vertical de Ourique The present study, of quantitative and qualitative content, is based on the thematic of the failure rate in schools. The study was oriented towards the fundamental issue which has been put in perspective: “What are the causes, consequences and dimension of the phenomena of the failure rate in schools that can be seen in the students that started in 1999/2000 their school education in the municipality of Ourique?” Based on the conceptual framework of a study case, we selected a group of students, which we interviewed, in order to know about the real experiences and situations that led them to situations of school failure, trying to give answers and to achieve the following goals: 1) to evaluate quantitatively the school failure of the selected students population; 2) to identify the eventual causes of the verified school failure; 3) to identify the eventual consequences of the verified school failure; 4) to evaluate the possible interventions in order to minimize the school failure phenomena. Therefore, we analysed the school path of an amount of 46 students between 1999/2000 and 2007/2008 and we reached the conclusion that 24 of those students experienced episodes of school failure. We interviewed 12 of those 24 and that approach permitted us to reach our goals. Through the analysis and the interpretation of the collected data we conclude that: 1) the rate of school failure is over 50% in the group of students that started their schooling in the school year 1999/2000 in the municipality of Ourique; 2) there is a strong participation of parents and tutors in the students’ school life( 80% of the sample); 3) the average number of retention in the students with episodes of school failure is 1, 5 retentions; 4) the 7th grade is the one in which we verify the highest number of retentions followed by the 4th grade ; 5) the majority of the students (53,8%) are far away from their family environment; 6) a significant number of students with episodes of school failure (83,3%) referred that they get support from their family; 7) the individual incapacity was the most referred/inferred cause of school failure by the ones who were interviewed ; 8) it became an evidence that early retentions lead to future retentions; 9) the importance of the basic education is relevant when the interviewed students show that the lack of support in the basic education should have led to future situations of school failure. At the end of this work we present some proposals that can lead to future investigation, namely of investigation/action promoting intervention.

O envolvimento da família na escola e no sucesso educativo das crianças: o caso dos 3º e 4º anos de escolaridade do agrupamento vertical de Colos (2004/2005)

Este trabalho pretende analisar a relação entre o envolvimento da família e o sucesso educativo das crianças. A hipótese principal foi construída para testar as teorias de Ana Henderson (1987), Davies (1989) e Epstein (2002). A primeira parte deste trabalho é constituída pelo enquadramento teórico, onde se abordam a problemática da relação escola/família, da participação e do sucesso e insucesso dos alunos. A segunda parte é constituída pela metodologia, análise e interpretação dos dados e análise e discussão dos resultados, onde estão incluídas as conclusões e as sugestões. O estudo foi feito nas escolas do 1° Ciclo do Agrupamento Vertical de Colos, relativamente aos alunos do 3° e 4° ano, no ano lectivo de 2004/2005. A amostra foi constituída por 67 pais e a recolha de informação foi feita através de um questionário. O tratamento de dados foi feito de forma estatística utilizando o SPSS, Os resultados do presente estudo levam-nos a concluir que os pais têm uma fraca participação na escola e que o sucesso educativo dos alunos não depende da participação dos pais na sua vida académica, não se confirmando a hipótese formulada para dar resposta à pergunta inicial. Concluímos ainda que, quanto maior é a distância entre a casa dos alunos e a escola frequentada, melhores resultados e menos retenções estes exibem ao longo do seu percurso escolar. /ABSTRACT - This work intends to analyse the relation between the role of the family and the educational success of children. The main assumption was built to test the theories of Ana Anderson (1987), Davies (1989) and Epstein (2002). The first part of the essay includes the theoretical framing where the subject of the relation school/family is approached. The second part contains the methodology, analysis and interpretation of data and the analysis and discussion of the results, which includes the conclusions and the suggestions. This survey was made in the Primary Schools of “Agrupamento Vertical de Colos”, among students of the third and fourth grades in the school year of 2004/2005. The sample was made of sixty-seven parents and the data was gathered by a questionnaire. The treatment of this data was made statistically by using SPSS. The results of this survey take us to the conclusion that parents have a low participation in school and that the educative success of students does not depend on their parents’ participation in their academic life. So, the hypothesis formulated to answer the initial question is not confirmed. We can also conclude that, the longer the distance between the students' home and the school they attend, the better the results and fewer times they fail in their school life.