Institute of Spring Technology

The greater wave energy content in deeper waters has initiated substantial research in offshore wave energy converters (WECs). However, the existing WECs are hindered by their high initial costs, primarily attributed to the demanding mechanical workloads they endure. This paper describes a novel wave energy conversion system developed at IST for deep waters (around 20-50 meters) based on a floater and a ballast, suspended by a set of cables. In the novel approach, the WEC is made up essentially by membranes, without a rigid structure, thus reducing the initial cost of investment comparing to other solutions.A simplified numerical model in the time-domain of the system based on linear theory is developed and a preliminary performance assessment under regular and irregular wave conditions (for conditions prevalent along the western coast of Portugal) is performed. Additionally, the effect of the ballast mass is considered. The results reveal the system's non-linear behavior during the floater's ascending phase and emphasize the significant influence of the ballast's mass on power production.

O presente artigo combina os aspetos tradicionais da gestão aplicada a realizações da Arquitetura, Engenharia e Construção (AEC) com os da área transdisciplinar emergente da gestão de ativos. Aborda também o papel da inovação e do empreendedorismo na afirmação da abordagem da gestão de ativos de engenharia com particular incidência no âmbito específico dos ativos construídos. Esta combinação justifica-se pelos crescentes desafios colocados na gestão de empreendimentos de infraestruturas, edifícios e instalações industriais que servem funções críticas para o funcionamento das sociedades. O envelhecimento e a natural degradação da condição deste tipo de sistemas de ativos físicos críticos implicam necessidades elevadas de investimento de renovação e modernização nas próximas décadas, exigindo a mobilização de recursos limitados que podem não estar imediatamente disponíveis. Isto tem atraído atenções para o potencial dos conceitos e princípios da gestão de ativos no domínio da Arquitetura, Engenharia e Construção (AEC) e para a necessária adaptação e inovação da abordagem clássica da gestão da construção e dos empreendimentos de construção para integrar esses mesmos conceitos e princípios.

This paper deals with the corruption and profiteering incidents and their reflections to the press which emerged in the extraordinary circumstances caused by the World War, I. In this context, the corruption and profiteering incidents that especially took place in the axis of the "Black Paw Company" were put forward in the light of the allegations in "Tasvir-i Efkar" and "kdm" newspapers. The relationship between corruption and the Committee of Union and Progress and its effects on the society had been examined.

<p>Este trabalho tem como principal objetivo verificar se diferentes linhas de costa iniciais,<br> extraídas de imagens de satélite e de sensores, influenciam os resultados da modelação da sua evolução<br> a longo prazo. Primeiramente, comparam-se as posições da linha de costa, em instantes próximos.<br> Seguidamente, determina-se em que medida a ordem de grandeza da variação inicial observada<br> influencia a evolução da linha de costa, usando o modelo numérico LITMOD. Verifica-se que as<br> imagens de satélite mais indicadas para a extração da linha de costa são as obtidas pelos sensores NIR<br> e RGB (satélite Sentinel2), concluindo-se que a morfologia da praia poderá influenciar a precisão da<br> extração da linha de costa. Ao usar o modelo LITMOD constata-se que a importância dos desvios<br> iniciais na posição da linha de costa se atenua com o tempo de simulação, embora haja um impacte<br> significativo no cálculo de sedimentos acumulados.</p>

Small-angle neutron scattering experiments, supported by molecular dynamics simulations, have been performed on a range of compositions of the [C2mim]1-x[C12mim]x[Tf2N] ionic liquid mixture system. Isotopic contrast variation, through selective deuteration of both cations, has been used to assist in fitting the data to different scattering models. These data, and subsequent fitting, show that the structure of the ionic liquid mixtures changes substantially as a function of composition. Mixtures where x < 0.32 are dominated by aggregates of amphiphilic [C12mim]+ ions in the relatively polar [C2mim][Tf2N] solvent. Compositions where x > 0.32 can be described as bicontinuous, containing networks of both polar and non-polar domains, where the C12 chains of the [C12mim]+ ions percolate through the system to form a continuous non-polar sub-phase. Temperature-dependent scattering experiments suggest that there is relatively little change in bulk structure in these liquids between 20 and 60 °C. The presence of water, however, does influence some aspects of the liquid structure in a composition that is rich in [C2mim][Tf2N] (where x = 0.24).

The BKMP conjecture (2006-2008), proposed a new method to compute closed and open Gromov-Witten invariants for every toric Calabi-Yau 3-folds, through a topological recursion based on mirror symmetry. So far, this conjecture had been verified to low genus for several toric CY3folds, and proved to all genus only for C^3. In this article we prove the general case. Our proof is based on the fact that both sides of the conjecture can be naturally written in terms of combinatorial sums of weighted graphs: on the A-model side this is the localization formula, and on the B-model side the graphs encode the recursive algorithm of the topological recursion. One can slightly reorganize the set of graphs obtained in the B-side, so that it coincides with the one obtained by localization in the A-model.Then it suffices to compare the weights of vertices and edges of graphs on each side, which is done in 2 steps: the weights coincide in the large radius limit, due to the fact that the toric graph is the tropical limit of the mirror curve. Then the derivatives with respect to K\"ahler radius coincide due to special geometry property implied by the topological recursion.

Global DNA hypomethylation affecting repeat sequences has been reported in different cancer types. Herein, we investigated the methylation levels of repetitive DNA elements in chronic lymphocytic leukemia (CLL), their correlation with the major cytogenetic and molecular features, and clinical relevance in predicting therapy-free survival (TFS). A quantitative bisulfite-PCR Pyrosequencing method was used to evaluate methylation of Alu, long interspersed nuclear elements-1 (LINE-1) and satellite-α (SAT-α) sequences in 77 untreated early-stage (Binet A) CLL patients. Peripheral B-cells from 7 healthy donors were used as controls. Methylation levels (median %5mC) were lower in B-CLLs compared with controls (21.4 vs. 25.9; 66.8 vs. 85.7; 84.0, vs. 88.2 for Alu, LINE-1 and SAT-α, respectively) (p < 0.001). Among CLL patients, a significant association was observed with 17p13.1 deletion (16.8 vs. 22.4; 51.2 vs. 68.5; 52.6 vs. 85.0, for Alu, LINE-1 and SAT-α) but not with other major genetic lesions, IgVH mutation status, CD38 or ZAP-70 expression. Follow-up analyses showed that lower SAT-α methylation levels appeared to be an independent prognostic marker significantly associated with shorter TFS. Our study extended previous limited evidences in methylation of repetitive sequences in CLL suggesting an important biological and clinical relevance in the disease.

A massively parallel simulation code, called \textit{dHybrid}, has been developed to perform global scale studies of space plasma interactions. This code is based on an explicit hybrid model; the numerical stability and parallel scalability of the code are studied. A stabilization method for the explicit algorithm, for regions of near zero density, is proposed. Three-dimensional hybrid simulations of the interaction of the solar wind with unmagnetized artificial objects are presented, with a focus on the expansion of a plasma cloud into the solar wind, which creates a diamagnetic cavity and drives the Interplanetary Magnetic Field out of the expansion region. The dynamics of this system can provide insights into other similar scenarios, such as the interaction of the solar wind with unmagnetized planets.

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Abstract The phase-coherent recording of pulsar data and subsequent software dispersion removal provide a flexible way to reach the limits of high time resolution, useful for more precise pulse timing and the study of fast signal fluctuations within a pulse. Because of the huge data rate and lack of adequate recording and computing capabilities, this technique has been used mostly only for small pulsar data sets. In recent years, however, the development of very capable, reasonably inexpensive high-speed recording systems and computers has made feasible the notion of pulsar baseband recording and subsequent processing with a workstation/computer. In this paper we discuss the development of a phase-coherent baseband processing system for radio pulsar observations. This system is based on the S2 VLBI recorder developed at ISTS/York University in Toronto, Canada. We present preliminary first results for data from the Vela pulsar, obtained at Parkes, Australia, and processed at ISTS/York University, and discuss plans for future developments.