Search

Thin-walled cylindrical shells are widely used as silos, liquid tanks, marine structures, and industrial chemical plants. In such applications, the shells are mostly exposed to liquids. Corrosion occurs on surfaces when shells are filled with low-pH liquids. Corroded material loss decreases the thickness of the shells which in turn lessens their buckling capacity. The current study primarily aims to investigate the effects of corrosion on the buckling capacity of thin-walled cylindrical shells subjected to uniform external pressure. The model shells were half- or full-filled with 5% and 10% HCl (Hydrochloric Acid) solutions for corrosion. In order to attenuate the negative effects of corrosion, the cylinders were coated with varying sizes of Carbon Fiber-Reinforced Polymer (CFRP) sheets. A total of 12 models of 800 x 400 x 0:45 mm in dimension were investigated in this research. The perfect non-corroded models were employed to compare the behavior of all models under study. The obtained results indicated that corrosion would cause a significant decrease in the buckling capacity of thin-walled cylindrical shells. It should be noted that the acid ratio, filling rate, and surface area coated with CFRP fabrics considerably affected the buckling capacity of cylinders. To be specific, coating the cylinders with one layer of CFRP moderated the buckling capacity loss. [ABSTRACT FROM AUTHOR]

Résumé: L'étude du microbiote digestif a connu un regain d'intérêt avec l'avènement des techniques moléculaires, en particulier la métagénomique. La culturomics (culture microbienne à haut débit avec identification des colonies par Maldi-TOF) a démontré sa complémentarité avec la métagénomique pour une étude exhaustive du microbiote. Les principales études de métagénomique ont révélé une augmentation de la biodiversité, avec en particulier une augmentation des Spirochaetes et des Prevotella chez les sujets d'origine africaine par rapport aux sujets occidentaux. Les études portant sur la malnutrition ont démontré une réduction de l'ensemble des bactéries et en particulier des bactéries anaérobies et des archées méthanogènes. Sur les 1162 bactéries isolées par étude de culturomics, 476 ont été isolées seulement de prélèvements d'origine autre que d'Afrique, 445 ont été isolées en commun et 241 bactéries n'ont été isolées qu'à partir de prélèvements d'origine africaine dont 68 nouvelles espèces. La poursuite d'études du microbiote africain par culturomics et métagénomique permettra d'élucider s'il existe une spécificité de certaines bactéries et si elles peuvent avoir un rôle dans certaines pathologies telles que la malnutrition. The interest in studying gut microbiota has been rekindled with the advent of molecular techniques, in particular, metagenomics. Culturomics (high throughput microbial culture with identification of the colonies by Maldi-TOF) has demonstrated its complementarity with metagenomics for comprehensive study of the microbiota. The main metagenomic studies have revealed an increase in biodiversity, with in particular an increase of Spirochaetes and Prevotella in subjects of African origin compared with Western subjects. Studies on malnutrition have shown a reduction of all bacteria and in particular of anaerobic bacteria and methanogenic archaea. Of the 1,162 bacteria isolated by culturomics studies, 476 were isolated only from non-African samples, 445 were isolated in African and non-African groups, and 241 bacteria were isolated from samples of African origin including 68 new species. Further studies of African microbiota by culturomics and metagenomics will make it possible to assess whether some bacteria have particular specificities and if these might play a role in certain pathologies such as malnutrition. [ABSTRACT FROM AUTHOR]

Arenaviridae comprises 23 recognized virus species with a bipartite ssRNA genome and an ambisense coding strategy. The virions are enveloped and include nonequimolar amounts of each genomic RNA species, designated L and S, coding for four ORFs (N, GPC, L, and Z). The arenavirus Junín (JUNV) is the etiological agent of Argentine Hemorrhagic Fever, an acute disease with high mortality rate. It has been proposed that Z is the functional counterpart of the matrix proteins found in other negative stranded enveloped RNA viruses. Here we report the optimized expression of a synthetic gene of Z protein, using three expression systems (two bacterial and a baculoviral one). One of these recombinant proteins was used to generate antibodies. A bioinformatic analysis was made where Z was subdivided into three domains. The data presented contributes methodologies for Z recombinant production and provides the basis for the development of new experiments to test its function. [ABSTRACT FROM AUTHOR]