Energy-based modelling of adhesive wear in the mixed lubrication regime

Adhesive wear in dry contacts is often described using the Archard or Fleischer model. Both provide equations for the determination of a wear volume, taking the load, the sliding path and a set of material parameters into account. While the Fleischer model is based on energetic approaches, the Archard formulation uses an empirical factor-the wear coefficient-describing the intensity of wear. Today, a numerical determination of the wear coefficient is already possible and both approaches can be deduced to a local accumulation of friction energy. The aim of this work is to enhance existing energy-based wear models into the mixed lubrication regime. Therefore, the pressure distribution within the contact area will be determined numerically taking real surface topographies into account. The emerging contact area will be divided into one part of solid and a second part of elastohydrodynamically lubricated (EHL) contacts. Based on the resulting pressure and shear stress distribution, the formation of micro cracks within the loaded volume will be described. Determining a critical number of load cycles for each asperity, a locally resolved wear coefficient will be derived and the local wear depth calculated

A mechanosensory receptor required for food texture detection in Drosophila.

Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition. Compared with our understanding of the chemosensory assessment of food, little is known about the mechanisms of texture detection. Here we show that Drosophila melanogaster can discriminate food texture, avoiding substrates that are either too hard or too soft. Manipulations of food substrate properties and flies' chemosensory inputs indicate that texture preferences are revealed only in the presence of an appetitive stimulus, but are not because of changes in nutrient accessibility, suggesting that animals discriminate the substrates' mechanical characteristics. We show that texture preference requires NOMPC, a TRP-family mechanosensory channel. NOMPC localizes to the sensory dendrites of neurons housed within gustatory sensilla, and is essential for their mechanosensory-evoked responses. Our results identify a sensory pathway for texture detection and reveal the behavioural integration of chemical and physical qualities of food

Satellite Water Column Data for Hydrography

Optical-band satellite images selected for satellite-derived bathymetry (SDB) analysis require clear water with low turbidity. As a result, image selection processes exclude images with excess turbidity regardless of cause. Images with water-column turbidity contain valuable information. Under certain conditions, vortex patterns in navigable waters are present in satellite imagery. Although vortex-induced turbidity excludes these images from SDB processing, the presence and shape of these vortices contain information relevant to hydrography. In this observational study, we use two case studies to describe vortex patterns and environmental conditions leading to their formation and then explore novel hydrographic survey applications of these phenomena.Las imágenes satelitales de banda óptica seleccionadas para el análisis debatimetría derivada de satélites (SDB) requieren agua clara con una baja turbidez.Como resultado, los procesos de selección de imágenes excluyen las imágenescon exceso de turbidez, independientemente de la causa.Las imágenes con turbidez en la columna de agua contienen información valiosa.En determinadas condiciones, los patrones de vórtices en aguas navegables estánpresentes en las imágenes satelitales. Aunque la turbidez inducida por losvórtices excluye estas imágenes del procesado SDB, la presencia y la forma deestos vórtices contienen información relevante para la hidrografía. En este estudiode observación, utilizamos dos estudios de casos para describir los patrones delos vórtices y las condiciones ambientales que llevan a su formación y luegoexploramos nuevas aplicaciones de estos fenómenos a los levantamientoshidrográficos.Les images satellitaires en bande optique sélectionnées pour l'analyse de labathymétrie dérivée par satellite (SDB) nécessitent une eau claire et de faibleturbidité. Par conséquent, les processus de sélection d'images excluent les imagesprésentant une turbidité excessive, quelle qu'en soit la cause.Les images qui montrent la turbidité dans la colonne d'eau contiennent desinformations précieuses. Dans certaines conditions, les images satellitairesmontrent des tourbillons dans les eaux navigables. Bien que la turbidité induite parles tourbillons exclue ces images du traitement SDB, la présence et la forme deces tourbillons contiennent des informations pertinentes pour l'hydrographie. Danscette étude basée sur l'observation, nous utilisons deux études de cas pour décrireles configurations des tourbillons et les conditions environnementales qui ontconduit à leur formation, puis nous explorons de nouvelles applications de cesphénomènes pour les levés hydrographiques

A Comparison of Time-Memory Trade-Off Attacks on Stream Ciphers

Contains fulltext : 117176.pdf (preprint version ) (Open Access

The impact of participation in online cancer communities on patient reported outcomes:Systematic review

Background: In recent years, the question of how patients’ participating in online communities affects various patient reported outcomes (PROs) has been investigated in several ways. Objectives: This study aimed to systematically review all relevant literature identified using key search terms, with regard to, first, changes in PROs for cancer patients who participate in online communities and, second, the characteristics of patients who report such effects. Methods: A computerized search of the literature via PubMed (MEDLINE), PsycINFO (5 and 4 stars), Cochrane Central Register of Controlled Trials, and ScienceDirect was performed. Last search was conducted in June 2017. Studies with the following terms were included: (cancer patient) and (support group or health communities) and (online or Internet). A total of 21 studies were included and independently assessed by 2 investigators using an 11-item quality checklist. Results: The methodological quality of the selected studies varied: 12 were of high quality, eight were of adequate quality, and only one was of low quality. Most of the respondents were women (about 80%), most with breast cancer; their mean age was 50 years. The patients who were active in online support groups were mostly younger and more highly educated than the nonusers. The investigated PROs included general well-being (ie, mood and health), anxiety, depression, quality of life, posttraumatic growth, and cancer-related concerns. Only marginal effects—that is, PRO improvements—were found; in most cases they were insignificant, and in some cases they were contradictory. Conclusions: The main shortcoming of this kind of study is the lack of methodological instruments for reliable measurements. Furthermore, some patients who participate in online communities or interact with peers via Internet do not expect to measure changes in their PROs. If cancer survivors want to meet other survivors and share information or get support, online communities can be a trustworthy and reliable platform to facilitate opportunities or possibilities to make this happen. Keywords: cancer; survivors; patient reported outcomes; Internet; support group