Particle shape dependence in 2D granular media

Particle shape is a key to the space-filling and strength properties of granular matter. We consider a shape parameter $\eta$ describing the degree of distortion from a perfectly spherical shape. Encompassing most specific shape characteristics such as elongation, angularity and nonconvexity, $\eta$ is a low-order but generic parameter that we used in a numerical benchmark test for a systematic investigation of shape-dependence in sheared granular packings composed of particles of different shapes. We find that the shear strength is an increasing function of $\eta$ with nearly the same trend for all shapes, the differences appearing thus to be of second order compared to $\eta$. We also observe a nontrivial behavior of packing fraction which, for all our simulated shapes, increases with $\eta$ from the random close packing fraction for disks, reaches a peak considerably higher than that for disks, and subsequently declines as $\eta$ is further increased. These findings suggest that a low-order description of particle shape accounts for the principal trends of packing fraction and shear strength. Hence, the effect of second-order shape parameters may be investigated by considering different shapes at the same level of $\eta$.Comment: 5 pages, 8 figure

Oxidation and oxygen diffusion in Ti-6al-4V alloy: improving measurements during sims analysis by rotating the sample

Titanium alloys are attractive to the industrial world, as they offer the benefits of low density, great corrosion resistance, and relatively good strength, making them viable candidates for a multitude of applications. However, above 500 °C, oxidation and oxygen diffusion in titanium alloys need to be taken into account as they change their microstructure and then their mechanical properties. Oxidations were carried out between 600 and 750 °C on a specific titanium alloy: an a-b annealed Ti-6Al-4V. Oxidation kinetics and oxygen diffusion in the matrix were studied. SIMS analyses were realized on rotating specimens of this two-phase polycrystalline alloy in order to reduce roughness. Composition profiles along the sample thickness were compared to microhardness measurements. SIMS mappings were realized on the smooth slopes of the crater

Improving prehospital trauma management for skiers and snowboarders - need for on-slope triage?

Background Injuries from skiing and snowboarding became a major challenge for emergency care providers in Switzerland. In the alpine setting, early assessment of injury and health status is essential for the initiation of adequate means of care and transport. Nevertheless, validated standardized protocols for on-slope triage are missing. This article can assist in understanding the characteristics of injured winter sportsmen and exigencies for future on-slope triage protocols. Methods Six-year review of trauma cases in a tertiary trauma centre. Consecutive inclusion of all injured skiers and snowboarders aged >15 (total sample) years with predefined, severe injury to the head, spine, chest, pelvis or abdomen (study sample) presenting at or being transferred to the study hospital. Descriptive analysis of age, gender and injury pattern. Results Amongst 729 subjects (total sample) injured from skiing or snowboarding, 401 (55%, 54% of skiers and 58% of snowboarders) suffered from isolated limb injury. Amongst the remaining 328 subjects (study sample), the majority (78%) presented with monotrauma. In the study sample, injury to the head (52%) and spine (43%) was more frequent than injury to the chest (21%), pelvis (8%), and abdomen (5%). The three most frequent injury combinations were head/spine (10% of study sample), head/thorax (9%), and spine/thorax (6%). Fisher's exact test demonstrated an association for injury combinations of head/thorax (p < 0.001), head/abdomen (p = 0.019), and thorax/abdomen (p < 0.001). Conclusion The data presented and the findings from previous investigations indicate the need for development of dedicated on-slope triage protocols. Future research must address the validity and practicality of diagnostic on-slope tests for rapid decision making by both professional and lay first responders. Thus, large-scale and detailed injury surveillance is the future research priority

A scalable monitoring for the CMS Filter Farm based on elasticsearch

A flexible monitoring system has been designed for the CMS File-based Filter Farm making use of modern data mining and analytics components. All the metadata and monitoring information concerning data flow and execution of the HLT are generated locally in the form of small documents using the JSON encoding. These documents are indexed into a hierarchy of elasticsearch (es) clusters along with process and system log information. Elasticsearch is a search server based on Apache Lucene. It provides a distributed, multitenant-capable search and aggregation engine. Since es is schema-free, any new information can be added seamlessly and the unstructured information can be queried in non-predetermined ways. The leaf es clusters consist of the very same nodes that form the Filter Farm thus providing natural horizontal scaling. A separate central" es cluster is used to collect and index aggregated information. The fine-grained information, all the way to individual processes, remains available in the leaf clusters. The central es cluster provides quasi-real-time high-level monitoring information to any kind of client. Historical data can be retrieved to analyse past problems or correlate them with external information. We discuss the design and performance of this system in the context of the CMS DAQ commissioning for LHC Run 2

A New Event Builder for CMS Run II

Abstract. The data acquisition system (DAQ) of the CMS experiment at the CERN Large Hadron Collider (LHC) assembles events at a rate of 100 kHz, transporting event data at an aggregate throughput of 100 GB/s to the high-level trigger (HLT) farm. The DAQ system has been redesigned during the LHC shutdown in 2013/14. The new DAQ architecture is based on state-of-the-art network technologies for the event building. For the data concentration, 10/40 Gbps Ethernet technologies are used together with a reduced TCP/IP protocol implemented in FPGA for a reliable transport between custom electronics and commercial computing hardware. A 56 Gbps Infiniband FDR CLOS network has been chosen for the event builder. This paper discusses the software design, protocols, and optimizations for exploiting the hardware capabilities. We present performance measurements from small-scale prototypes and from the full-scale production system

La performance des pratiques interorganisationnelles innovantes. Proposition d'un modèle conceptuel

La collaboration entre partenaires industriels et logistiques est un pilier du Supply Chain Management (SCM). Soumis à des problématiques toujours renouvelées, le SCM implique de nouvelles pratiques de collaboration. Comment caractériser les pratiques interorganisationnelles innovantes (P2I) dans le contexte du SCM ? Quels sont leurs effets sur la performance de la supply chain ? Cet article répond à ces questions en montrant que la capacité d’innovation de l’organisation a un impact plus important sur la performance de la P2I que les conditions et le contexte de déploiement

Pratiques inter-organisationnelles innovantes (P2I) dans le Supply Chain Management : Développement et validation d'un instrument de mesure

Innover est devenu aujourd’hui un élément déterminant dans la performance des entreprises. Une des voies de l’innovation passe par le management ses relations inter-organisationnelles. Pour cela, les organisations doivent aller au-delà de la conception traditionnelle de l’innovation technologique et produit, en développant l’innovation managériale. L’émergence, ces dernières années, de pratiques de Supply Chain Management (SCM), telles que le CPFR (Collaborative Planning, Forcasting and Replenishment ), la GMA (Gestion Mutualisée des Approvisionnements), le Kanban fournisseur ou le MAF (Magasin Avancé Fournisseur), témoigne de l’engouement managérial pour ce type d’innovations et doit pousser les chercheurs à les étudier. Pour comprendre de telles pratiques, il est nécessaire de disposer d'un instrument de mesure. Or, dans le cas de notre objet d'étude, l'instrument de mesure n'existe pas, car les échelles utilisées dans la littérature sont peu adaptées. L'objectif de notre recherche est donc de développer et de valider un instrument de mesure desPratiques Inter-organisationnelles Innovantes (P2I) dans le Supply Chain Management (SCM). Cet instrument de mesure se compose de trois échelles de mesure : les conditions et le contexte de déploiement, la capacité d'innovation de l'organisation, et la performance de l'innovation. Pour chacune d'elles, nous avons suivi la démarche méthodologique canonique en trois étapes : construction, purification et validation