What is absolutely continuous spectrum?

This note is an expanded version of the author's contribution to the Proceedings of the ICMP Santiago, 2015, and is based on a talk given by the second author at the same Congress. It concerns a research program devoted to the characterization of the absolutely continuous spectrum of a self-adjoint operator H in terms of the transport properties of a suitable class of open quantum systems canonically associated to H

Integrated support structure

This Major Qualifying Project is part of the Advanced Space Design Program at WPI. The goal is to design a support structure for a NASA GetAway Special experimental canister. The payload integration, weight, volume, and structural integrity of the canister as specified by NASA guidelines were studied. The end result is a complete set of design drawings with interface drawings and data to specify the design and leave a base on which the next group can concentrate

Experimental Study of Longitudinally Stiffened Web Channels Subjected Predominantly to Shear

The Direct Strength Method (DSM) of design of cold-formed sections has recently been extended in the North American Specification for Cold-Formed Steel Structural Members-NAS S100:2012 to include shear. The two new features of the DSM rules for shear researched are the effect of full-section shear buckling as opposed to web-only shear buckling and Tension Field Action (TFA). The prequalified sections in the rules include sections with flat webs and webs with small intermediate longitudinal stiffeners. In order to extend the range to larger intermediate stiffeners as occurs in practice, a series of fourteen shear tests have been performed at the University of Sydney for C-sections with rectangular stiffeners of varying sizes. Six different types of stiffeners were tested with an additional preferred plain section. Each type of sections was tested twice to ensure accuracy. As the web stiffener sizes increase, the shear buckling and strength of the sections are expected to improve accordingly. However, the tests show that the shear ultimate strengths only increase slightly in association with the respective increase of stiffener sizes. The test results are compared with the DSM design rules for shear and found to be lower than those predicted by the DSM curve for shear with TFA. The test failures were observed mainly due to the combined bending and shear modes. The effect of the bending is therefore significant and starts to govern when the shear capacity is significantly strengthened by adding the large longitudinal web stiffener. The test results are subsequently plotted against the DSM interaction curves between bending and shear where the interaction is found to be significant. Modifications and recommendations for prequalified sections with longitudinally stiffened web channels in shear are proposed in the paper

Nouveau concept de séchage et de fumage artisanal des aliments : application en milieu de pêche artisanale au Gabon

L’objet de cette étude est de présenter la conception détaillée et la fabrication d’un fumoir à poissons dont les spécificités permettent de répondre aux besoins de PED (pays en développement) côtiers tropicaux liés au traitement de poissons fraîchement péchés. Cette technique de séchage et fumage correspond à un mode de conservation traditionnel en Afrique subsaharienne et permet l’exportation des produits finis. Le dispositif de fumage proposé ici est autonome en ce sens qu’il fonctionne sans électricité et ne nécessite que l’utilisation de bois de combustion et de bois de pyrolyse ; il est de plus modulaire et réalisable avec les matériaux et les outils standards de la maçonnerie et de la chaudronnerie. Il permet de séparer en deux phases distinctes, les opérations de séchage et de fumage. Le séchage des poissons se fait par convection, conduction et rayonnement à partir des conduites de fumées. De ce fait, nous avons une chaleur uniforme au sein de l'enceinte. Le système de fumage permet d'obtenir une teneur des benzo (a) pyrène recommandé par les organismes internationaux.Mots-clés : bois, conception, fumage, PED, poissons, séchage.New concept of drying and smoking of artisanal foods : application in middle of artisanal fishing in GabonThe purpose of this study is to present the detailed design and construction of a fish smokehouse whose characteristics can meet the needs of tropical coastal developing countries related to the treatment of freshly caught fish. This technique of drying and smoking is a traditional way of conservation in subSaharan Africa and allows the export of finished products. The smoking device proposed here is autonomous in the sense that it works without electricity and requires only the wooden use of combustion and wood of pyrolysis; it is of more modular and built with materials and standard tools of the masonry and the boilermaking. He allows to separate in two different phases, the operations of drying and smoking. The drying of fishes is made by convection, conduction and radiation with smoke ducts. Therefore, we have a uniform heat within the smokehouse. The system of smoking allows to obtain a content of benzo ( a ) pyrène recommended by the international bodies.Keywords : wood, design, smoking, PED, fish, drying

Ruthenium(II) and Iridium(III) complexes featuring NHC-Sulfonate chelate

International audienc

Objective determination of the predefined duration of a constant-load diagnostic tests in arterial claudication

OBJECTIVE: The predefined duration to arbitrarily stop the tests during constant-load treadmill exercise is a subject of debate and widely variable in the literature. We hypothesized that the upper and lower limits for predefined durations of constant-load 3.2 km/hour 10% grade tests could be derived from the distribution of walking distances observed on a treadmill in a population of subjects referred for claudication or from the optimal cutoff point distance on a treadmill to confirm a limitation self-reported by history.METHODS: We conducted a retrospective analysis using a referral center, institutional practice, and ambulatory patients. We studied 1290 patients (86% male), 62.1 +/- 11.2 years of age, 169 +/- 8 cm height, 75.7 +/- 14.2 kg weight. Patients performed a standard constant-load treadmill test: 3.2 km hour(-1), 10% slope, maximized to 1000 meters (approximately 20 minutes). We analyzed the maximal walking distance self-reported (MWD(SR)) by history and the maximal walking distance measured on the treadmill (MWD(TT)). Patients reporting MWD(SR) >or=1000 meters were considered unlimited by history. RESULTS: Only 197 patients (15.3%) completed the 20-minute treadmill test. Among the 504 patients who did not stop before 250 meters, 47.8% stopped within the next 250 meters (were unable to walk 500 meters). This proportion falls to 7.5% among the 213 patients who did not stop before 750 meters. When the final goal was to estimate whether the treadmill test can discriminate patients with or without limitation by history, area under the receiver operating characteristic (ROC) curve was 0.809 +/- 0.016 (95% confidence interval [CI], 0.778-0.841; P < .0001), the best diagnostic performance was attained for an MWD(TT) of 299 meters (approximately 6.15 minutes). CONCLUSION: In patients undergoing constant-load treadmill exercise with a protocol of 3.2 km hour(-1) and 10% slope: a predefined duration of 7 minutes could be proposed as a lower limit for the predefined duration of the tests specifically if one aims at confirming the limitation by history with treadmill testing. Owing to the low risk that patients that could walk 750 meters (approximately 15 minutes) will have to stop in the next 250 meters, 15 minutes seems a reasonable upper limit for the predefined test duration in clinical routine

Experimental study of Taylor's hypothesis in a turbulent soap film

An experimental study of Taylor's hypothesis in a quasi-two-dimensional turbulent soap film is presented. A two probe laser Doppler velocimeter enables a non-intrusive simultaneous measurement of the velocity at spatially separated points. The breakdown of Taylor's hypothesis is quantified using the cross correlation between two points displaced in both space and time; correlation is better than 90% for scales less than the integral scale. A quantitative study of the decorrelation beyond the integral scale is presented, including an analysis of the failure of Taylor's hypothesis using techniques from predictability studies of turbulent flows. Our results are compared with similar studies of 3D turbulence.Comment: 27 pages, + 19 figure

Social Functioning and Self-Esteem in Young People with Disabilities Participating in Adapted Competitive Sport

Aims: The aim of this study was to investigate social functioning quality of life and self-esteem in young people with disabilities taking part in adapted competitive sport.Method: A sample of 496 athletes (mean age 16 years 4 months, range: 9 years to 20 years 9 months) was obtained from the 540 participants (91.8%) involved in a French national championship. The main outcome measurements were a social functioning inventory (PedsQL 4.0 social functioning) and a self-esteem inventory in physical areas (physical self inventory 6 PSI-6). Results: The mean PedsQL SF score was 74.6 (SD: 17.7). Comparisons of PedsQL SF according to gender, age, self mobility and training revealed no significant differences between the groups. PedsQL SF was weakly but significantly correlated with all subscales of the PSI-6 in the total population. PSI-6 scores were significantly different between boys and girls, with better self-esteem for boys on general self-esteem (7.7 vs. 6.9, p=0.018), physical condition (6.8 vs. 6.0, p=0.023) and attractive body subscores (6.5 vs. 5.1, p<0.001). Conclusion: Social functioning scores were significantly higher in this population than in the samples of young people with disabilities available in the literature. Interactions between self-concept, social functioning quality of life and participation in adapted sport activities require further studies