200 research outputs found

    Finite elements prediction of thermal stresses in work roll of hot rolling mills

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    AbstractA simplified numerical approach based on finite elements to compute thermal stresses occurring in work roll of hot rolling mills is here proposed. To decrease both the complexity of the analysis and the computational effort, this approach implements a plane finite element model of the work roll alone, loaded on its surface by the rotating thermal actions due to the cyclic sequence of the conductive heating caused by the contact with hot strip and cooling provided by water jets. Results from thermal analysis are preliminary compared to an analytical solution available in the literature and then applied as thermal input in the subsequent mechanical finite elements simulations, which provide thermal stress in the work roll and the elastic-plastic evolution of elements, close to the work roll surface

    Proposal of a Modelling of the Innovation Process in an International Manufacturing Company

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    Nowadays, to cope with the competition, and to ensure the durability of their activities, companies have to be able to innovate. Manufacturing companies operating in a B2B market often perceive innovation as a technological result. However, innovation is often more characterized as a process. The needs of the users, and not only the technology, can achieve innovation. In this context, our paper intends to determine how to involve better the users in the innovation process of an international manufacturing company, which is, according to us, representative of the current manufacturing companies. The aim of our research paper is to help manufacturing companies to manage innovation led by users, and to implement their innovation process so that they will be able to set up specific tools for each action of the process. The study proposes a diagram-based language Structured Analysis and Design Technique (SADT) that is based on the normative guide FD X50-271 of the French national organization for standardization (AFNOR). The SADT model we propose usefully complements this guide, to make the innovation process more understandable, practical and operational, for manufacturing companies, which are often helpless when faced with the subject. A critical analysis of the model we propose completed in a manufacturing company through semi-structured interviews of the innovation team and questionnaire for all the employees shows the application of the model in the company

    Proposition d’un outil d’aide au diagnostic du syndrome du canal carpien pour les acteurs de la santĂ© au travail

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    Les acteurs de la santĂ© au travail sont confrontĂ©s Ă  un manque d’outils quantitatifs de suivi et de diagnostic du syndrome du canal carpien (SCC). Pour rĂ©pondre Ă  ce manque, un outil de diagnostic du SCC est proposĂ© dans cette communication. Il est composĂ© de deux tests : le test de la roue qui consiste Ă  dĂ©tecter des encoches sur une roue en mouvement et le test de la poutre qui dĂ©tecte un niveau de sensibilitĂ© Ă  une force exercĂ©e sur un doigt concernĂ© par le SCC. Deux Ă©tudes expĂ©rimentales ont Ă©tĂ© conduites pour valider cet appareil. La premiĂšre Ă©tude montre que les mesures effectuĂ©es avec l’appareil sont rĂ©pĂ©tables, la seconde vise Ă  Ă©tudier la sensibilitĂ© et la spĂ©cificitĂ© de l’outil en comparaison avec une Ă©tude Ă©lectrodiagnostique. Les rĂ©sultats montrent que l’appareil de dĂ©tection du SCC a un excellent pouvoir discriminant permettant d’identifier les sujets sains et les sujets atteints du SCC.People involved with occupational health at work are faced with a lack of quantitative tools to monitor and diagnose Carpal Tunnel Syndrome (CTS). In order to fill this gap, we developed a device for rapid CTS diagnosis which is composed of two complementary quantitative tests: the wheel test, which consists in detecting notches on a rotating wheel, and the beam test, which consists in detecting various forces exerted on a finger. We conducted two experimental studies to validate this device. The first one demonstrated the repeatability of the measures. The second one studied the sensitivity and specificity of our tool as compared to an electro-diagnosis test. The results show that our CTS detection device has excellent discriminatory power that allows practitioners to differentiate between healthy and CTS-affected subjects.Los actores de la salud en el trabajo se enfrentan a una falta de herramientas cuantitativas de seguimiento y de diagnĂłstico del sĂ­ndrome del tĂșnel carpiano (STC). Como respuesta a esa limitante, se propone una herramienta de diagnĂłstico del STC compuesta de dos exĂĄmenes : el examen de la rueda, que consiste en detectar las muescas de una rueda en movimiento y el examen de la viga, que detecta un nivel de sensibilidad a una fuerza ejercida sobre un dedo afectado por el STC. Dos estudios experimentales fueron realizados para validar este dispositivo. El primero muestra que las medidas efectuadas con el equipo son repetibles ; el segundo busca estudiar la sensibilidad y la especificidad de la herramienta en comparaciĂłn con un estudio de electrodiagnĂłstico. Los resultados muestran que el dispositivo de detecciĂłn del STC tiene un excelente poder discriminante, permitiendo identificar los sujetos sanos y los sujetos afectados por el STC

    Seasonal response of benthic foraminifera to anthropogenic pressure in two stations of the Gulf of Trieste (northern Adriatic Sea, Italy): the marine protected area of Miramare versus the Servola water sewage outfall

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    A seasonal survey of living benthic foraminifera was performed in 2013 in the Gulf of Trieste (N Adriatic Sea) to compare two marine coastal sites with different degrees of anthropogenic influence. An assessment of ecological quality statuses showed that the station located near the end of an urban pipeline (Ser station), has worse ecological conditions than the site located in a protected marine area (Res station) all year around. Stressed conditions at Ser station were mainly related to high contents of total organic carbon (TOC) and Zn in the bioavailable fraction, which were a limiting factor for the studied foraminiferal communities. Ammonia tepida, Bolivina spp., and Bulimina spp., which characterised this station, were the most tolerant taxa of the studied assemblage. Conversely, Elphidium spp., H. depressula, N. iridea, Quiqueloculina spp., R. nana and Textularia spp., could be considered less tolerant species as they benefitted from the less stressful conditions recorded at Res station, despite slightly higher concentrations of some potentially toxic elements (PTEs), especially Pb, being recorded in this station in comparison to Ser station. Furthermore, foraminiferal assemblages were found to be quite resilient over an annual cycle, being able to recover from a seasonal unbalanced state to a mature one. The beginning of spring and latest summer would be the best period to assess the ecological quality status to avoid any under- or overestimation of the health of the environment

    Vers une méthodologie de développement d'outils de réalité virtuelle pour faciliter la convergence métiers en conception de produits centrée sur l'homme

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    La conception concourante de produits matĂ©riels centrĂ©e sur l homme est basĂ©e sur une collaboration entre le concepteur mĂ©canicien, l ergonome et le designer industriel. Cette collaboration souvent difficile peut ĂȘtre facilitĂ©e par l utilisation d objets intermĂ©diaires de conception, tels que la RĂ©alitĂ© Virtuelle (RV). NĂ©anmoins, bien que largement utilisĂ©e dans l industrie, la RV souffre d un dĂ©ficit d acceptation de la part des concepteurs de produits. Dans le cadre de ces travaux, nous proposons d utiliser la RV sous la forme d outils immersifs d assistance Ă  la convergence multidisciplinaire dĂ©veloppĂ©s selon une dĂ©marche anthropocentrĂ©e en fonction des besoins spĂ©cifiques Ă  chaque projet de conception de produits. Afin d optimiser les dĂ©lais de dĂ©veloppement, nous proposons une mĂ©thodologie de conception d applications immersive dĂ©diĂ©e : la mĂ©thodologie ASAP(As Soon As Possible). Une premiĂšre sĂ©rie expĂ©rimentale a Ă©tĂ© conduite dans le cadre de contrats industriels d Ă©tudes et de recherche afin de valider la faisabilitĂ© de la mĂ©thodologie et l efficacitĂ© des outils dĂ©veloppĂ©s.Une deuxiĂšme sĂ©rie expĂ©rimentale a Ă©tĂ© effectuĂ©e sur plus de 50 sujets dans le cadre de projets, cette fois, pĂ©dagogiques qui ont nĂ©cessitĂ© le dĂ©veloppement de 12 applications. Elle a permis de valider quantitativement l influence des outils immersifs sur l efficacitĂ© perçue des phases de convergence interdisciplinaires ainsi que l influence de l approche proposĂ©e sur l acceptation de la RV par les concepteurs de produits. Ces travaux de thĂšse prĂ©sentent une premiĂšre approche qui, selon nous, permettra Ă  terme, de faire Ă©voluer l usage de la RV vers une intĂ©gration plus forte au sein des processus de conception de produits avec, par exemple, une plus large utilisation des applications immersives de modĂ©lisation 3D, rĂ©elles sources d innovation.Human centered and concurring product design is based on the collaboration between mechanical engineers, human factor experts and industrial designers. This collaboration is often difficult and can be eased through the use of intermediary objects such as Virtual Reality (VR). Nevertheless, even though VR is widely used in the industry, it suffers from a lack of acceptance by product designers. In the context of this research work, we suggest to use VR in the form of immersive multidisciplinary convergence support tools. These tools are developed in accordance with an anthropocentered approach, as a function of each specific product design project s needs. In order to optimize development times, we propose a dedicated immersive software design methodology : the ASAP methodology (As Soon As Possible). A first experiment, aiming to demonstrate the feasibility of the ASAP methodology and the effectiveness of the implemented immersive tools, has been conducted in the context of industrial product design projects. A second experiment, involving more than 50 participants, has been conducted in the context of educational product design projects and led to the development of 12 immersivetools. It demonstrated quantitatively the contribution of immersive tools to the perceived effectiveness of interdisciplinary convergence phases and the contribution of the ASAP methodology on the acceptation of VR by product designers. This research work describes a first approach that could, according to us, allow abetter integration of VR within product design processes.BELFORT-UTBM-SEVENANS (900942101) / SudocSudocFranceF

    Microbial processing of sedimentary organic matter at a shallow LTER site in the northern Adriatic Sea: an 8-year case study

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    Benthic prokaryotes are the key-players in C-cycling at the sediment-seawater interface, one of the largest biologically active interfaces on Earth. Here, microbial-mediated processes, such as the degradation of organic matter and the incorporation of mobilized C into microbial biomass, depend on several factors such as environmental temperature and substrate availability, especially in shallow sediments at mid-high latitudes where seasonal fluctuations of these variables occur. In the present study, four degradative activities (ÎČ-glucosidase, lipase, chitinase and aminopeptidase), Heterotrophic C Production (HCP), Total Organic C (TOC), Total Nitrogen (TN) and Biopolymeric C (BPC) were investigated seasonally from April 2010 to April 2018 in the surface sediments of a shallow Long-Term Ecological Research (LTER) station of the northern Adriatic Sea. Significant temperature-dependences were described by Arrhenius-type equations for HCP and each of the degradative activities tested with the exception of aminopeptidase. The relatively low apparent Activation Energies suggested that these microbial-mediated processes were enhanced by the availability of palatable substrates over the study period. Nevertheless, a clear and tight dependence from such substrates was detected only for aminopeptidase, the most pronounced degradative activity observed. TN was identified by the stepwise multiple regression analysis as the environmental variable that mainly drove this exoenzymatic activity. Enhanced aminopeptidase rates mirrored peaks of TN that seemed, in turn, linked to the seasonal proliferation of benthic microalgae. By supplying prokaryotes with promptly available substrates, these autotrophs, represented mainly by diatoms, seemed to play an important role in the C-cycling regulation at the studied LTER station

    Stressing the Ubiquitin-Proteasome System without 20S Proteolytic Inhibition Selectively Kills Cervical Cancer Cells

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    Cervical cancer cells exhibit an increased requirement for ubiquitin-dependent protein degradation associated with an elevated metabolic turnover rate, and for specific signaling pathways, notably HPV E6-targeted degradation of p53 and PDZ proteins. Natural compounds with antioxidant properties including flavonoids and triterpenoids hold promise as anticancer agents by interfering with ubiquitin-dependent protein degradation. An increasing body of evidence indicates that their α-ÎČ unsaturated carbonyl system is the molecular determinant for inhibition of ubiquitin-mediated protein degradation up-stream of the catalytic sites of the 20S proteasome. Herein we report the identification and characterization of a new class of chalcone-based, potent and cell permeable chemical inhibitors of ubiquitin-dependent protein degradation, and a lead compound RAMB1. RAMB1 inhibits ubiquitin-dependent protein degradation without compromising the catalytic activities of the 20S proteasome, a mechanism distinct from that of Bortezomib. Treatment of cervical cancer cells with RAMB1 triggers unfolded protein responses, including aggresome formation and Hsp90 stabilization, and increases p53 steady state levels. RAMB1 treatment results in activation of lysosomal-dependent degradation pathways as a mechanism to compensate for increasing levels of poly-ubiquitin enriched toxic aggregates. Importantly, RAMB1 synergistically triggers cell death of cervical cancer cells when combined with the lysosome inhibitor Chloroquine

    UCS protein function is partially restored in the Saccharomyces cerevisiae she4 mutant with expression of the human UNC45-GC, but not UNC45-SM

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    A dedicated UNC45, Cro1, She4 (UCS) domain-containing protein assists in the Hsp90-mediated folding of the myosin head. Only weak sequence conservation exists between the single UCS protein of simple eukaryotes (She4 in budding yeast) and the two UCS proteins of higher organisms (the general cell and striated muscle UNC45s; UNC45-GC and UNC45-SM, respectively). In vertebrates, UNC45-GC facilitates cytoskeletal functions, whereas the 55% identical UNC45-SM assists assembly of the contractile apparatus of cardiac and skeletal muscles. A Saccharomyces cerevisiae she4Δ mutant, totally lacking any UCS protein, was engineered to express as its sole Hsp90 either the Hsp90α or the Hsp90ÎČ isoforms of human cytosolic Hsp90. A transient induction of the human UNC45-GC, but not UNC45-SM, could rescue the defective endocytosis in these she4Δ cells at 39 °C, irrespective of whether they possessed Hsp90α or Hsp90ÎČ. UNC45-GC-mediated rescue of the localisation of a Myo5-green fluorescent protein (GFP) fusion to cortical patches at 39 °C was more efficient in the yeast containing Hsp90α, though this may relate to more efficient functioning of Hsp90α as compared to Hsp90ÎČ in these strains. Furthermore, inducible expression of UNC45-GC, but not UNC45-SM, could partially rescue survival at a more extreme temperature (45 °C) that normally causes she4Δ mutant yeast cells to lyse. The results indicate that UCS protein function has been most conserved-yeast to man-in the UNC45-GC, not UNC45-SM. This may reflect UNC45-GC being the vertebrate UCS protein that assists formation of the actomyosin complexes needed for cytokinesis, cell morphological change, and organelle trafficking-events also facilitated by the myosins in yeast

    Myosin Assembly, Maintenance and Degradation in Muscle: Role of the Chaperone UNC-45 in Myosin Thick Filament Dynamics

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    Myofibrillogenesis in striated muscle cells requires a precise ordered pathway to assemble different proteins into a linear array of sarcomeres. The sarcomere relies on interdigitated thick and thin filaments to ensure muscle contraction, as well as properly folded and catalytically active myosin head. Achieving this organization requires a series of protein folding and assembly steps. The folding of the myosin head domain requires chaperone activity to attain its functional conformation. Folded or unfolded myosin can spontaneously assemble into short myosin filaments, but further assembly requires the short and incomplete myosin filaments to assemble into the developing thick filament. These longer filaments are then incorporated into the developing sarcomere of the muscle. Both myosin folding and assembly require factors to coordinate the formation of the thick filament in the sarcomere and these factors include chaperone molecules. Myosin folding and sarcomeric assembly requires association of classical chaperones as well as folding cofactors such as UNC-45. Recent research has suggested that UNC-45 is required beyond initial myosin head folding and may be directly or indirectly involved in different stages of myosin thick filament assembly, maintenance and degradation

    Cellular and Molecular Networking Within the Ecosystem of Cancer Cell Communication via Tunneling Nanotubes

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    Intercellular communication is vital to the ecosystem of cancer cell organization and invasion. Identification of key cellular cargo and their varied modes of transport are important considerations in understanding the basic mechanisms of cancer cell growth. Gap junctions, exosomes, and apoptotic bodies play key roles as physical modalities in mediating intercellular transport. Tunneling nanotubes (TNTs)—narrow actin-based cytoplasmic extensions—are unique structures that facilitate direct, long distance cell-to-cell transport of cargo, including microRNAs, mitochondria, and a variety of other sub cellular components. The transport of cargo via TNTs occurs between malignant and stromal cells and can lead to changes in gene regulation that propagate the cancer phenotype. More notably, the transfer of these varied molecules almost invariably plays a critical role in the communication between cancer cells themselves in an effort to resist death by chemotherapy and promote the growth and metastases of the primary oncogenic cell. The more traditional definition of “Systems Biology” is the computational and mathematical modeling of complex biological systems. The concept, however, is now used more widely in biology for a variety of contexts, including interdisciplinary fields of study that focus on complex interactions within biological systems and how these interactions give rise to the function and behavior of such systems. In fact, it is imperative to understand and reconstruct components in their native context rather than examining them separately. The long-term objective of evaluating cancer ecosystems in their proper context is to better diagnose, classify, and more accurately predict the outcome of cancer treatment. Communication is essential for the advancement and evolution of the tumor ecosystem. This interplay results in cancer progression. As key mediators of intercellular communication within the tumor ecosystem, TNTs are the central topic of this article
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