Twenty years of experience with carbon/ceramic brakes: Status and perspectives

Carbon/ceramic brakes can be regarded as a successful spin-off from space technology to terrestrial applications. First attempts in the nineties of last century started to use carbon fiber reinforced silicon carbide (C/SiC) as heat sink materials in high performance brake systems. Originally, these materials were developed for thermal protection systems (TPS) of spacecraft. Meanwhile, LSI-derived C/C-SiC composites have proven their outstanding performance for frictional applications by demonstrating high and stable coefficients of friction and low wear rates. Today, these ceramic composite materials are used in series products for high performance brake systems in automotive and industrial applications (e.g. brake discs, pads for emergency brakes of elevators). High coefficients of friction which are constant over a wide range of sliding velocities and pressures have been achieved with appropriate counterpart materials. Specific modifications of the C/C-SiC microstructure in terms of matrix composition, fiber dimension and thermophysical properties were necessary and result in composite materials which differ widely from the original TPS-material. The development of an automotive brake system comprising C/C-SiC brake discs and organic based pads led to a lifetime brake which makes a brake disc change obsolete. The further success of these innovative materials, however, is strongly dependent on the reduction of the production costs and the development of light-weight ceramic brakes with life cycle costs (LCC) comparable to the current cast iron brakes. The presentation describes the development and evolution of carbon/ceramic brake discs and pads over the last twenty years, summarizes the state-of-the-art, and gives a perspective to future demands and challenges in process technology and material development

Regularized Newton Methods for X-ray Phase Contrast and General Imaging Problems

Like many other advanced imaging methods, x-ray phase contrast imaging and tomography require mathematical inversion of the observed data to obtain real-space information. While an accurate forward model describing the generally nonlinear image formation from a given object to the observations is often available, explicit inversion formulas are typically not known. Moreover, the measured data might be insufficient for stable image reconstruction, in which case it has to be complemented by suitable a priori information. In this work, regularized Newton methods are presented as a general framework for the solution of such ill-posed nonlinear imaging problems. For a proof of principle, the approach is applied to x-ray phase contrast imaging in the near-field propagation regime. Simultaneous recovery of the phase- and amplitude from a single near-field diffraction pattern without homogeneity constraints is demonstrated for the first time. The presented methods further permit all-at-once phase contrast tomography, i.e. simultaneous phase retrieval and tomographic inversion. We demonstrate the potential of this approach by three-dimensional imaging of a colloidal crystal at 95 nm isotropic resolution.Comment: (C)2016 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibite

Betreibermodell einer Forschungsinfrastruktur für die Entwicklung intelligenter Mobilitätsdienste im realen Verkehrsumfeld

Mit der Anwendungsplattform Intelligente Mobilität (AIM) steht am Institut für Verkehrssystemtechnik des Deutschen Zentrums für Luft- und Raumfahrt e.V. (DLR) ein umfassender Baukasten für die Entwicklung und prototypische Erprobung intelligenter Mobilitätsdienste und neuer Verkehrsinfrastrukturkomponenten, sowie zugehöriger Software zur Verfügung. Mit dem langfristigen Betrieb der Forschungsinfrastruktur bis geht das DLR weit über den Rahmen konventioneller Forschungsprojekte mit temporär betriebenen Anlagen hinaus. Die geschaffene Forschungsinfrastruktur steht für gemeinsame Projekte mit Partnern aus Industrie und Wissenschaft zur Verfügung. Die Wiederverwendung vorhandener Bausteine führt zu einer Kosten- und Zeitersparnis in der praktischen Demonstration wissenschaftlicher Erkenntnisse. Dieser Beitrag stellt die besonderen Herausforderungen eines dauerhaften Betriebes einer Forschungsinfrastruktur im öffentlichen Straßenraum dar

Advancing liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry toward ultra-high-throughput analysis

Label-free high-throughput screening using mass spectrometry has the potential to provide rapid large-scale sample analysis at a speed of more than one sample per second. Such speed is important for compound library, assay and future clinical screening of millions of samples within a reasonable time frame. Herein, we present a liquid atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) setup for high-throughput large-scale sample analysis (>5 samples per second) for three substance classes (peptides, antibiotics and lipids). Liquid support matrices (LSM) were used for the analysis of standard substances as well as complex biological fluids (milk). Throughput and analytical robustness were mainly dependent on the complexity of the sample composition and the current limitations of the commercial hardware. However, the ultimate limits of liquid AP-MALDI in sample throughput can be conservatively estimated to be beyond 10-20 samples per second. This level of analytical speed is highly competitive compared with other label-free MS methods, including electrospray ionization and solid state MALDI, as well as MS methods using multiplexing by labelling, which in principle can also be used in combination with liquid AP-MALDI MS

A finite-step method for estimating the spanwise lift distribution of wings in symmetric, yawed, and rotary flight at low speeds

The finite-step method was programmed for computing the span loading and stability derivatives of trapezoidal shaped wings in symmetric, yawed, and rotary flight. Calculations were made for a series of different wing planforms and the results compared with several available methods for estimating these derivatives in the linear angle of attack range. The agreement shown was generally good except in a few cases. An attempt was made to estimate the nonlinear variation of lift with angle of attack in the high alpha range by introducing the measured airfoil section data into the finite-step method. The numerical procedure was found to be stable only at low angles of attack

Slender body theory programmed for bodies with arbitrary cross section

A computer program developed for determining the subsonic pressure, force, and moment coefficients for a fuselage-type body using slender body theory is described. The program is suitable for determining the angle of attack and sideslipping characteristics of such bodies in the linear range where viscous effects are not predominant. Procedures developed which are capable of treating cross sections with corners or regions of large curvature are outlined

Características Estruturais e Funções das Redes Sociais Significativas de Mulheres Ex-Abrigadas

The aim of this qualitative study was to understand the structural characteristics and functions of the significant social networks of women subjected to violence, after their stay in a shelter. Six women admitted to a shelter in southern Brazil participated in the study. Semi-structured interviews and Network Maps were used for data collection. Data were organized and analyzed according to Grounded Theory, using the software Atlas.ti 7.0. Medium and large networks were found, with a high degree of affective proximity and the predominance of family members. The main functions were Emotional Support, and Cognitive Guidance and Advice. Participants were considerably empowered by reactivating their significant social networks and resignifying the quality of their relational bond with them.O objetivo deste estudo qualitativo foi compreender as características estruturais e funções  das redes sociais significativas de mulheres que sofreram violência, após a passagem por uma casa-abrigo. Participaram seis mulheres que haviam sido acolhidas numa casa-abrigo da região Sul do Brasil. Para coleta de dados, utilizou-se a entrevista semiestruturada e o Mapa de Redes. A organização e análise dos dados tiveram como referência a Grounded Theory e o software Atlas.ti 7.0. Observaram-se redes de tamanho médio e grande, com maior grau de proximidade afetiva e predomínio de membros da família. As principais funções foram apoio emocional e guia cognitivo e de conselhos. Destaca-se o empoderamento das participantes em reativar e ressignificar a qualidade do vínculo relacional com suas redes sociais significativas.O objetivo deste estudo qualitativo foi compreender as características estruturais e funções  das redes sociais significativas de mulheres que sofreram violência, após a passagem por uma casa-abrigo. Participaram seis mulheres que haviam sido acolhidas numa casa-abrigo da região Sul do Brasil. Para coleta de dados, utilizou-se a entrevista semiestruturada e o Mapa de Redes. A organização e análise dos dados tiveram como referência a Grounded Theory e o software Atlas.ti 7.0. Observaram-se redes de tamanho médio e grande, com maior grau de proximidade afetiva e predomínio de membros da família. As principais funções foram apoio emocional e guia cognitivo e de conselhos. Destaca-se o empoderamento das participantes em reativar e ressignificar a qualidade do vínculo relacional com suas redes sociais significativas.O objetivo deste estudo qualitativo foi compreender as características estruturais e funções das redes sociais significativas de mulheres que sofreram violência, após a passagem por uma casa-abrigo. Participaram seis mulheres que haviam sido acolhidas numa casa-abrigo da região Sul do Brasil. Para coleta de dados, utilizou-se a entrevista semiestruturada e o Mapa de Redes. A organização e análise dos dados ocorreram com base na Grounded Theory e contou com o auxílio do software Atlas.ti 7.0. Observaram-se redes de tamanho médio e grande, com maior grau de proximidade afetiva e predomínio de membros da família. As principais funções foram apoio emocional e guia cognitivo e de conselhos. Destaca-se o empoderamento das participantes em reativar e ressignificar a qualidade do vínculo relacional com suas redes sociais significativas

Violência no contexto familiar

A primeira unidade mostra a família como um sistema relacional dinâmico, a estrutura e dinâmica familiar, os diferentes tipos de fronteiras familiares e as mudanças ao longo de seu ciclo vital. A segunda unidade apresenta as repercussões da violência no sistema familiar: conceituação e características de sua sustentação nas diferentes fases do ciclo vital da família, a intergeracionalidade da violência e a violência familiar na perspectiva do Modelo Ecológico. A terceira unidade trata das condições de intervenção junto às famílias que vivem e convivem com a violência, a necessidade de reconhecimento dos pressupostos profissionais para o trabalho com a violência familiar, os conhecimentos e as reflexões necessárias para uma postura profissional diferenciada e para fundamentar as práticas, o planejamento e a organização profissional no processo de intervenção familiar, os aspectos necessários para uma escuta qualificada, os instrumentos de intervenção que favorecem o trabalho das equipes de saúde no acolhimento das famílias em situação de violência – o genograma e mapa de redes.1.0Ministério da Saúd

Improved molecular descriptors based on the optimization of correlation weights of local graph invariants

We report the calculation of boiling points for several alkyl alcohols through the use of improved molecular descriptors based on the optimization of correlation weights of local invariants of graphs. As local invariants we have used the presence of different chemical elements (i.e. C, H, and O) and the existence of different vertex degree values (i.e. 1, 2, 3 and 4). The inherent flexibility of the chosen molecular descriptor seems to be rather suitable to obtain satisfactory enough predictions of the property under study. Comparison with other similar approximation reveals a very good behavior of the present method. The use of higher order polynomials do not seem to be necessary to improve results regarding the simple linear fitting equations. Some possible future extensions are pointed out in order to achieve a more definitive conclusion about this approximation