Solid motor diagnostic instrumentation

A review of typical surveillance and monitoring practices followed during the flight phases of representative solid-propellant upper stages and apogee motors was conducted to evaluate the need for improved flight diagnostic instrumentation on future spacecraft. The capabilities of the flight instrumentation package were limited to the detection of whether or not the solid motor was the cause of failure and to the identification of probable primary failure modes. Conceptual designs of self-contained flight instrumentation packages capable of meeting these reqirements were generated and their performance, typical cost, and unit characteristics determined. Comparisons of a continuous real time and a thresholded hybrid design were made on the basis of performance, mass, power, cost, and expected life. The results of this analysis substantiated the feasibility of a self-contained independent flight instrumentation module as well as the existence of performance margins by which to exploit growth option applications

Linear LL-positive sets and their polar subspaces

In this paper, we define a Banach SNL space to be a Banach space with a certain kind of linear map from it into its dual, and we develop the theory of linear $L$-positive subsets of Banach SNL spaces with Banach SNL dual spaces. We use this theory to give simplified proofs of some recent results of Bauschke, Borwein, Wang and Yao, and also of the classical Brezis-Browder theorem.Comment: 11 pages. Notational changes since version

Ceiling-fan-integrated air conditioning: Airflow and temperature characteristics of a sidewall-supply jet interacting with a ceiling fan

Ceiling-Fan-Integrated Air Conditioning (CFIAC) is a proposed system that can greatly increase buildings’ cooling efficiency. In it, terminal supply ducts and diffusers are replaced by vents/nozzles, jetting supply air toward ceiling fans that serve to mix and distribute it within the room. Because of the fans’ air movement, the system provides comfort at higher room temperatures than in conventional commercial/ institutional/retail HVAC. We have experimentally evaluated CFIAC in a test room. This paper covers the distributions of air-speed, temperature, and calculated comfort level throughout the room. Two subsequent papers report tests of human subject comfort and ventilation effectiveness in the same experimental conditions. The room’s supply air emerged from a high-sidewall vent directed toward a ceiling fan on the jet centerline; we also tested this same jet on a fan located off to the side of the jet. Primary variables are: ceiling fan flow volumes in downward and upward directions, supply air volume, and room-vs-supply temperature difference. Velocity, turbulence, and temperature distributions are presented for vertical and horizontal transects of the room. The occupied zone is then evaluated for velocity and temperature non-uniformity, and for comfort as predicted by the ASHRAE Standard 55 elevated air speed method. We show that temperatures are well-mixed and uniform across the room for all of the fan-on configurations, for fans both within or out of the supply jet centerline. The ceiling fan flow dominates the CFIAC airflow, and even though non-uniform is capable of providing comfortable conditions throughout the occupied area of the room

Large Extra Dimension Effects on the Spin Configuration of the Top Quark Pair at e^+ e^- Colliders

Large extra dimension effects on the spin configuration of the top quark pair at the $e^+ e^-\to t\bar{t}$ process are studied. It is shown that the TeV scale quantum gravity effects cause significant deviations from the Standard Model predictions for the spin configuration in the off-diagonal basis: they lead to substantial cross sections of the like-spin states of the top quark pair, which vanish in the SM; they weaken the pure dominance of the processes, the Up-Down (Down-Up) spin states for the left-handed (right-handed) beam. In addition it is shown that the angular cut $-0.5<\cos\theta<0$ is very effective to determine the sign of the quantum gravity corrections.Comment: A discussion on the angular distribution is added with a tabl

Relations between classroom disciplinary problems and student motivation : Achievement as a potential mediator?

This study examined the relation between classroom disciplinary problems in language classes, student achievement, and three facets of student motivation: competence self-perceptions, test anxiety, and engagement. The analyses were conducted with the German sample from the Progress in International Reading Literacy Study (PIRLS) 2006 (N = 7899). The results demonstrated that discipline problems are directly and negatively related to achievement and to all motivation constructs considered. In most cases, the relation between classroom disciplinary problems and motivation constructs was mediated by verbal achievement. Boys were found to report more frequent discipline problems in classrooms than girls. This study contributes to research by assessing the impact of classroom disciplinary problems using doubly latent multilevel structural equation models in order to properly disaggregate effects occurring at the student, versus classroom level

A Nyström method for a class of integral equations on the real line with applications to scattering by diffraction gratings and rough surfaces

We propose a Nystr¨om/product integration method for a class of second kind integral equations on the real line which arise in problems of two-dimensional scalar and elastic wave scattering by unbounded surfaces. Stability and convergence of the method is established with convergence rates dependent on the smoothness of components of the kernel. The method is applied to the problem of acoustic scattering by a sound soft one-dimensional surface which is the graph of a function f, and superalgebraic convergence is established in the case when f is infinitely smooth. Numerical results are presented illustrating this behavior for the case when f is periodic (the diffraction grating case). The Nystr¨om method for this problem is stable and convergent uniformly with respect to the period of the grating, in contrast to standard integral equation methods for diffraction gratings which fail at a countable set of grating periods

Characterization of type-III secreted bacterial virulence factors that interfere with Rho-GTPase signalling

Bakterien, wie Salmonella enterica, Shigella flexneri oder pathogenen Escherichia coli verursachen Infektionskrankheiten. Um eine bakterielle Infektion zu etablieren, manipulieren Bakterien mit Hilfe von eingeschleusten Virulenzfaktoren die Signalwege der Wirtszelle. Im Rahmen dieser Arbeit habe ich mich mit den Virulenzfaktoren der WxxxE Familie befasst, die als bakterielle GEFs wirken. Mit Hilfe eines Y2H screenings wurde nach weiteren Interaktionspartnern auf Seiten des Wirtes gesucht. So konnten unter anderem deutliche Hinweise auf eine Interaktion zwischen dem humanen, Protein Rhophilin1 (RHPN1) und dem Virulenzfaktor Map aus EPEC gefunden werden. Außerdem wird gezeigt, dass der Virulenzfaktor IpgB2 (S. flexneri) mit dem Bardet-Biedl Syndrom Protein 4 (BBS4) und das bakterielle Protein SifA (S. enterica) mit der kleinen GTPase Rab9 interagieren kann. Zusammengefasst zeigt diese Arbeit, dass das Funktionsspektrum der Virulenzfaktoren weit über die einfache GEF Aktivität hinausgeht.<br/