177 research outputs found

    A Review and Analysis of the Thermal Exposure in Large Compartment Fire Experiments

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    Developments in the understanding of fire behaviour for large open-plan spaces typical of tall buildings have been greatly outpaced by the rate at which these buildings are being constructed and their characteristics changed. Numerous high-profile fire-induced failures have highlighted the inadequacy of existing tools and standards for fire engineering when applied to highly-optimised modern tall buildings. With the continued increase in height and complexity of tall buildings, the risk to the occupants from fire-induced structural collapse increases, thus understanding the performance of complex structural systems under fire exposure is imperative. Therefore, an accurate representation of the design fire for open-plan compartments is required for the purposes of design. This will allow for knowledge-driven, quantifiable factors of safety to be used in the design of highly optimised modern tall buildings. In this paper, we review the state-of-the-art experimental research on large openplan compartment fires from the past three decades. We have assimilated results collected from 37 large-scale compartment fire experiments of the open-plan type conducted from 1993 to 2019, covering a range of compartment and fuel characteristics. Spatial and temporal distributions of the heat fluxes imposed on compartment ceilings are estimated from the data. The complexity of the compartment fire dynamics is highlighted by the large differences in the data collected, which currently complicates the development of engineering tools based on physical models. Despite the large variability, this analysis shows that the orders of magnitude of the thermal exposure are defined by the ratio of flame spread and burnout front velocities (VS / VBO), which enables the grouping of open-plan compartment fires into three distinct modes of fire spread. Each mode is found to exhibit a characteristic order of magnitude and temporal distribution of thermal exposure. The results show that the magnitude of the thermal exposure for each mode are not consistent with existing performance-based design models, nevertheless, our analysis offers a new pathway for defining thermal exposure from realistic fire scenarios in large open-plan compartments

    Améliorer la qualité technologique, nutritionnelle et sanitaire du bléiologique. Principaux leviers agronomiques et technologiques

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    Communication lors du colloque "DinABio 2013", 13 et 14 novembre 2013 Ă  Tours (Fance)The organic bread wheat market has been diversified over time through the emergence of different sale channels. Processors require organic bread wheat of higher quality and safety in order to meet the consumers’ demand. The overall objective of the AGTEC-Org project was to identify agronomical and technological ways to improve the performance of organic wheat and flour. The findings would contribute to enhanced baking quality and nutritional value of organic flour, as well as prevention of mycotoxin contamination. The project involved 9 research centers or universities from 5 European countries for a total budget of about 1.5 million €. More than 400 experimental treatments were analyzed from 23 agronomic trials and 4 lab-experiments on food technology. Choice of cultivar is an efficient way to obtain higher grain quality. Intercropping legumes (grain or forage) improves weed control and N availability for wheat crop or succeeding crop. Green manure can be an effective alternative to farmyard manure. Fertilization with organic fertilizers improves yield and quality when water is available. Reduced tillage affects soil fertility and wheat yield but has little effects on grain quality. Milling process strongly influences flour characteristics. Stone milling improves the nutritive value and flour characteristics remain very stable independently of the milling yield. However, stone milling slightly raises DON levels. Characteristics of flour produced by means of roller milling appear very dependent on milling yield, instead. Increasing milling yield with the aim of enriching nutritional quality has a detrimental effect on either safety (DON) or bread-making quality (bread volume). Debranning before milling has a very positive impact on flour safety by reducing its DON content by 50 %.Les acteurs de la filiĂšre blĂ© biologique panifiable font face Ă  divers enjeux complĂ©mentaires voire parfois contradictoires. Les agriculteurs et transformateurs souhaitent augmenter les niveaux de production tout en satisfaisant prioritairement les attentes des consommateurs pour une alimentation de meilleure qualitĂ© nutritionnelle et sanitaire, plus durable et plus respectueuse de l’environnement. Le projet europĂ©en AGTEC-Org a eu pour objectif d’identifier les leviers agronomiques et technologiques permettant d’amĂ©liorer conjointement la productivitĂ© et la qualitĂ© des blĂ©s et des farines biologiques. Il a rĂ©uni agronomes, technologues et Ă©conomistes issus de 9 centres de recherche et universitĂ©s europĂ©ennes pour un budget total de 1,5 M€. Plus de 400 traitements expĂ©rimentaux ont Ă©tĂ© analysĂ©s Ă  partir de 23 expĂ©rimentations agronomiques et 4 expĂ©rimentations technologiques. Le choix de la variĂ©tĂ© est un moyen efficace pour obtenir une qualitĂ© de grain supĂ©rieure. L’insertion de lĂ©gumineuses (grain ou fourrage) dans le blĂ© amĂ©liore la compĂ©tition avec les adventices et la nutrition azotĂ©e du blĂ© et/ou de la culture de printemps suivante. L’utilisation rĂ©guliĂšre d’engrais vert peut ĂȘtre une alternative pour compenser l’absence de fumiers sur l’exploitation. La fertilisation organique amĂ©liore le rendement et la qualitĂ© des blĂ©s lorsque la nutrition hydrique est assurĂ©e. La suppression du labour peut affecter la fertilitĂ© du sol et le rendement du blĂ© alors qu’elle n’intervient pas sur la qualitĂ© du grain. Le mode de broyage (meule de pierre vs cylindres) influence fortement les caractĂ©ristiques technologiques, la sĂ©curitĂ© sanitaire et la valeur nutritionnelle de la farine. Le broyage sur meule amĂ©liore la composition nutritionnelle mais augmente aussi la prĂ©sence de certains contaminants. Les caractĂ©ristiques de la farine broyĂ©e sur meule de pierre sont moins influencĂ©es par le rendement en mouture. Au contraire, les caractĂ©ristiques de la farine obtenue par cylindre apparaissent trĂšs dĂ©pendantes du rendement en mouture. Augmenter le rendement en farine dans l’objectif d’enrichir la qualitĂ© nutritionnelle rĂ©duit aussi bien la sĂ©curitĂ© sanitaire (DON) que la qualitĂ© boulangĂšre (volume du pain). Le dĂ©corticage des grains avant broyage diminue les risques sanitaires en rĂ©duisant le taux de mycotoxines (DON) de 50%

    Improving baking quality, nutritional value and safety of organic winter wheat / Améliorer la qualité technologique, nutritionnelle et sanitaire du blé biologique, Principaux leviers agronomiques et technologiques

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    The organic bread wheat market has been diversified over time through the emergence of different sale channels. Processors require organic bread wheat of higher quality and safety in order to meet the consumers’ demand. The overall objective of the AGTEC-Org project was to identify agronomical and technological ways to improve the performance of organic wheat and flour. The findings would contribute to enhanced baking quality and nutritional value of organic flour, as well as prevention of mycotoxin contamination. The project involved 9 research centers or universities from 5 European countries for a total budget of about 1.5 million €. More than 400 experimental treatments were analyzed from 23 agronomic trials and 4 lab-experiments on food technology. Choice of cultivar is an efficient way to obtain higher grain quality. Intercropping legumes (grain or forage) improves weed control and N availability for wheat crop or succeeding crop. Green manure can be an effective alternative to farmyard manure. Fertilization with organic fertilizers improves yield and quality when water is available. Reduced tillage affects soil fertility and wheat yield but has little effects on grain quality. Milling process strongly influences flour characteristics. Stone milling improves the nutritive value and flour characteristics remain very stable independently of the milling yield. However, stone milling slightly raises DON levels. Characteristics of flour produced by means of roller milling appear very dependent on milling yield, instead. Increasing milling yield with the aim of enriching nutritional quality has a detrimental effect on either safety (DON) or bread-making quality (bread volume). Debranning before milling has a very positive impact on flour safety by reducing its DON content by 50 %

    The dynamics of experiential learning: Microprocesses and adaptation in a professional service INV

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    In international new ventures (INVs), experiential learning happens in quick succession and across a wide number of diverse contexts. Yet, we lack an empirical understanding of the microprocesses through which INVs learn and adapt in their foreign expansion. Understanding those microprocesses is important because timely adaptation can save the venture time and resources, thus promoting sustainable growth. In this study, we investigate the dynamics of experiential learning and adaptation in the internationalisation process of an INV in the professional service sector. Findings from our study illustrate that the firm applies deliberate experiential learning by developing, revising, and finalising criteria for important dimensions in the international growth process, and adapts its internationalisation practices accordingly. We further show that deliberate experiential learning is predicated on an actively and closely monitored learning process, involving critical evaluation, adjustment of criteria, and acceptance of affordable mistakes, as opposed to learning by defaul

    CTIP2 Expression in Human Head and Neck Squamous Cell Carcinoma Is Linked to Poorly Differentiated Tumor Status

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    We have demonstrated earlier that CTIP2 is highly expressed in mouse skin during embryogenesis and in adulthood. CTIP2 mutant mice die at birth with epidermal differentiation defects and a compromised epidermal permeability barrier suggesting its role in skin development and/or homeostasis. CTIP2 has also been suggested to function as tumor suppressor in cells, and several reports have described a link between chromosomal rearrangements of CTIP2 and human T cell acute lymphoblast leukemia (T-ALL). The aim of the present study was to look into the pattern of CTIP2 expression in Head and Neck Squamous Cell Carcinoma (HNSCC).In the present study, we analyzed CTIP2 expression in human HNSCC cell lines by western blotting, in paraffin embedded archival specimens by immunohistochemistry (IHC), and in cDNA samples of human HNSCC by qRT-PCR. Elevated levels of CTIP2 protein was detected in several HNSCC cell lines. CTIP2 staining was mainly detected in the basal layer of the head and neck normal epithelium. CTIP2 expression was found to be significantly elevated in HNSCC (p<0.01), and increase in CTIP2 expression was associated with poorly differentiated tumor status. Nuclear co-localization of CTIP2 protein and cancer stem cell (CSC) marker BMI1 was observed in most, if not all of the cells expressing BMI1 in moderately and poorly differentiated tumors.We report for the first time expression of transcriptional regulator CTIP2 in normal human head and neck epithelia. A statistically significant increase in the expression of CTIP2 was detected in the poorly differentiated samples of the human head and neck tumors. Actual CTIP2, rather than the long form of CTIP2 (CTIP2(L)) was found to be more relevant to the differentiation state of the tumors. Results demonstrated existence of distinct subsets of cancer cells, which express CTIP2 and underscores the use of CTIP2 and BMI1 co-labeling to distinguish tumor initiating cells or cancer stem cells (CSCs) from surrounding cancer cells

    Gastrointestinal stromal tumours: ESMO-EURACAN-GENTURIS Clinical Practice Guidelines for diagnosis, treatment and follow-up

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    Gastrointestinal stromal tumours (GISTs) are malignant mesenchymal tumours with a variable clinical behaviour, marked by differentiation towards the interstitial cells of Cajal. GISTs belong to the family of soft tissue sarcomas (STSs) but are treated separately due to their peculiar histogenesis, clinical behaviour and specific therapy. This European Society for Medical Oncology (ESMO)–European Reference Network for Rare Adult Solid Cancers (EURACAN)–European Reference Network for Genetic Tumour Risk Syndromes (GENTURIS) Clinical Practice Guideline (CPG) will cover GISTs while other STSs are covered in the ESMO–EURACAN–European Reference Network for Paediatric Oncology (ERN PaedCan)–GENTURIS STS CPG
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