EVOLUTION MICROSTRUCTURALE ET MECANIQUE D’UN ACIER FAIBLEMENT ALLIE A FAIBLE POURCENTAGE ENCARBONE AVANT ET APRES EMBOUTISSAGE

Cette étude est réaliséesur le métal de base, ensuite après emboutissage à froid sous une pression de 200 bars. Le but de cette investigation est l'étude de l’évolution microstructurale et mécanique d’un acier industriel faiblement allié à faible pourcentage en carbone utilisé pour la fabrication des réservoirs àgaz par la SNS BAG Batna.Le vifde ce travail est de montrer que le procédé d’emboutissage à froid à un effet important, notre attention sera ciblé sur l’évolution duparamètre mécanique de dureté le long des emboutis par une analyse de l’acier deson état de livraison et après emboutissage. Des observations de microscopie électronique à balayage (MEB) montrent les différences de structures qui se manifestent par un grossissement des grains et avec l’usage de la diffraction des Rayons X (DRX), nous confirmons les changements structurels qui s’opèrent, les résultats obtenus nous ramène à déduire que l’emboutissage à froid affecte la taille de grain de la structure de cet acier et cela se répercute sur les propriétés mécaniques. This study is realized into base metal, then after cold stamping process under 200 Bars pressure. The goal of this investigation is to follow the microstructural evolution and mechanical properties of industrial low carbon steel used in the gas store manufacture by SNS BAG Batna factory. In this work we saw the important effect of cold stamping process and more importance is given to the hardness parameter in order to show the structural change between base metal and cold stamping metal, scanning electronic microscopy observations shows more structural differences obvious by a grain magnification and by using Xray diffraction we confirm this structural changes.The obtain results let us concluded that cold stamping process affect the grain size of low carbon steel structural form and affect also their mechanical properties

Systemic Inflammatory Response Syndrome from Nitrofurantoin: A Case Report

BACKGROUND: Nitrofurantoin is an antibiotic that is commonly used and preferred to treat lower urinary tract infections due to its relatively safe adverse effects profile. However, with the increased emphasis on antibiotic stewardship, it is important to recognize the rare, yet serious adverse effects profile of this medication. One of the rare adverse reactions is the development of systemic inflammatory response syndrome from nitrofurantoin. CASE REPORT: We present a case of a 66-year-old woman who developed a classic systemic inflammatory response syndrome, including leukocytosis and fevers, after 2 repeated exposures to nitrofurantoin after a urological procedure. The patient had an initial infectious workup which was negative. A suspected adverse reaction to nitrofurantoin was suspected and the patient was found to have complete resolution of symptoms with discontinuation of the drug and with supportive treatment. CONCLUSIONS: This case demonstrates that although nitrofurantoin is known to be relatively well tolerated, clinicians should still be aware of the adverse reactions, including a potential systemic inflammatory response, from nitrofurantoin use. This information should be used to educate patients going forward on potential adverse effects to be aware of

Analyse par diffraction neutrons de la texture d’un acier industriel à faible pourcentage en carbone avant et après emboutissage

Résumé : Dans ce travail, une analyse de texture par diffraction neutrons avant et après déformation mécanique par le procédé d’emboutissage d’un acier faiblement allié et à faible pourcentage en carbone (0,19%) à été étudié, cet acier est destiné à la fabrication des réservoirs à gaz.          Pour réaliser notre objectif deux types de spécimens ont été investis, le premier concerne le métal de base à son état de livraison et le second après son passage à la presse sous une force de 200 tonnes soit après le procédé d’emboutissage. La fibre α et la fibre γ ont été clairement  identifiés ainsi que leurs composantes.           Ce travail représente une contribution quantitative dans l’étude de ce type d’acier industriel par l’usage de la caractérisation des diffractions neutrons et l’analyse ODF des neutrons.Mots clés : Diffraction Neutrons- aciers à faible pourcentage en carbone- texture- emboutissage

EMPIRICAL MODELS FORLOSSES CALCULATION IN A RECTANGULAR DUCT EQUIPPED BYARTIFICIALROUGHNESS

The objective of this work is to find empirical models linking load losses to the geometric characteristics of artificial roughness called baffles and different modes of provisions of these fluids in the vein of a rectangular channel.An experimental design was set up to measure the lossesLoadcausedby baffles between the upstream and downstream of the channel. The experimental measurements made have enabled us to establish empirical relationships to evaluate losses in accordance with load losses configuration and arrangement of baffles and for different flow regimes

THEORETICAL APPROACH ON THE STUDY OF TURBULENT WATER FLOW OVER SMOOTH AND L-SHAPED RIBLETS SURFACES

A very important research effort has been developed at many world laboratories these last years in order to reduce the friction drag. For the aircraft and the submarine applications, friction contributes respectively for about 50% and 70% of the total resistance. The use of surface modifications riblets as a means of reducing viscous drag on a body has potential aerodynamic and hydrodynamic applications. In the present study, the theoretical approach allow to determine the velocity field, the wall shear stress, the local skin friction, the boundary layer thickness, the laminar sub layer thickness and the dimensionless drag coefficient. The results found, indicate that the presence of L-shaped riblets surfaces provide changes in the characteristics of the turbulent boundary layer, which are in favor of wall skin friction. Un effort très important a été fourni ces dernières années à travers les laboratoires du monde dans le domaine de la réduction de traînée visqueuse. Pour les avions de transport et les sous marins, la traînée visqueuse contribue respectivement d’environ 50% à 70% de la résistance totale. L’utilisation des modifications au niveau de la surface est un moyen efficace pour réduire la traînée visqueuse dans les applications aérodynamique et hydrodynamique. Dans cette étude, l’approche théorique permis de déterminer le champ de vitesse, la contrainte de cisaillement à la paroi, le coefficient de frottement local, l’épaisseur de la couche limite, l’épaisseur de la sous couche visqueuse et finalement le coefficient non dimensionnel de traînée sont représentés. Les résultats trouvés ont montré que la présence des rainures en lames " L " fournie des changements dans les caractéristiques de la couche limite turbulente, qui sont en faveur du coefficient de frottement pariétal

EMPIRICAL MODELS FOR LOSSES CALCULATION IN A RECTANGULAR DUCT EQUIPPED BY ARTIFICIAL ROUGHNESS

The objective of this work is to find empirical models linking load losses to the geometric characteristics of artificial roughnesscalled baffles and different modes of provisions of these fluids in the vein of a rectangular channel.An experimental design was set up to measure the losses Load caused by baffles between the upstream and downstream of thechannel. The experimental measurements made have enabled us to establish empirical relationships to evaluate losses inaccordance with load losses configuration and arrangement of baffles and for different flow regimes

Early virological response to HIV treatment: can we predict who is likely to experience subsequent treatment failure? Results from an observational cohort study, London, UK

INTRODUCTION: For people living with HIV, the first antiretroviral treatment (ART) regimen offers the best chance for a good virological response. Early identification of those unlikely to respond to first‐line ART could enable timely intervention and increase chances of a good initial treatment response. In this study we assess the extent to which the HIV RNA viral load (VL) at 1 and 3 months is predictive of first‐line treatment outcome at 6 months. METHODS: All previously ART‐naive individuals starting ART at two London centres since 2000 with baseline (−180 to 3 days) VL >500 c/mL had a VL measurement between 6 and 12 months after starting ART, and at least one at month 1 (4–60 days) or month 3 (61–120 days) were included. Lack of treatment response was defined as (i) VL >200 copies/mL at 6 months or (ii) VL >200 copies/mL at 6 months or simultaneous switch in drugs from at least two different drug classes before 6 months. The association with VL measurements at 1 and 3 months post‐ART; change from pre‐ART in these values; and CD4 count measurements at 1 and 3 months were assessed using logistic regression models. The relative fit of the models was compared using the Akaike information criterion (AIC). RESULTS: A total of 198 out of 3258 individuals (6%) experienced lack of treatment response at 6 months (definition i), increasing to 511 (16%) for definition (ii). Those with a 1‐month (day 4–60 window) VL of 100,000 copies/ml had a 4%, 8%, 23% and 24% chance, respectively, of subsequently experiencing treatment non‐response at 6 months (definition (i)). When considering the 3‐month (day 61–120 window) VL, the chances of subsequently experiencing treatment non‐response were, respectively, 3%, 25%, 67% and 75%. Results were similar for definition (ii). CONCLUSIONS: Whilst 3‐month VL provides good discrimination between low and high risk of treatment failure, 1‐month VL does not. Presence of a VL >10,000 copies/ml after 3 months of ART is a cutoff above which individuals are at a sufficiently higher risk of non‐response that they may be considered for intervention

DYNAMICAL STUDY OF THE FLOW ALONG A TWO-DIMENSIONAL CHANNELWITH A RIGHT ANGLED BEND

A two-dimensional incompressible laminar flow passing through a constant width channel with a ninety-degree turn is investigated. Based on the flow separation and recirculation phenomena downstream of the inner corner , a model profile for the axial velocity component is chosen. Concerning the channel segments upstream and downstream of the previous corner, the insertion of the velocity profiles (incorporating a distortion profile function) in the Navier-Stocks equations and the use of the integral method lead to a linear differential equation for the previous function. Whereas, the corresponding previous differential equation is not linear in the corner region. The analytical and numerical solutions for the first and last equations respectively are obtained and the Reynolds number Re as well as recirculation bubble effects on the flow variables are presented for () 540 Re 100 ≤ ≤ ; the experimental range of flow visualisation and measurement )L'écoulement incompressible, laminaire et bidimensionnel le long d'une conduite coudée à 90° a été étudié. En se basant sur le phénomène de séparation et de recirculation just après le coude, un modèle de profil de la composante de vitesse axiale est choisie. Concerant les deux parties en amant et en aval du coude, l'introduction du profile de vitesse (introduction du profil de la function de deformation) à l'interieur des équations de "Navier Stocks" et l'utilisation de la méthode intégrale menent à une équation différentielle linéaire dont l'inconnue est bien la fonction de déformation. Alors que, l'équation différentielle précédente est non linéaire au niveau du coude. Les solutions analytique et numérique respectivement pour la première et la dernière équation différentièlle sont obtenues. L'effet du nombre de Reynolds aussi bien de la bulle de recirculation sur les variables de l'écoulement est présenté pour 100 Re 540 ≤< (plage expérimentale de mesure et visualization)

An interactive website to aid young women's choice of contraception: feasibility and efficacy RCT

Background: Effective use of contraception can reduce numbers of unintended pregnancies, but misunderstandings and concerns about contraception abound. Increasingly, women seek health-care information online. / Objectives: To develop an interactive website to aid informed choice of contraceptive method, including long-acting reversible contraception (Phase I), and test its effectiveness in a parallel, single-blind randomised trial (Phase II). Approval came from London – Camden & King’s Cross Research Ethics Committee (reference 17/LO/0112). / Setting and participants: For both phases, women aged 15–30 years were recruited from general practice, sexual health services, maternity services, community pharmacies and an abortion service. / Design: In Phase I, we conducted three systematic literature reviews, a review of YouTube (YouTube, LLC, San Bruno, CA, USA) videos about contraception, and focus groups and interviews with young women to explore barriers to and concerns and misperceptions about contraception. We then iteratively co-designed an interactive website, Contraception Choices [URL: www.contraceptionchoices.org (accessed June 2020)], with young women and a software company. In Phase II, we evaluated the website through a randomised trial that began as a feasibility trial. Early demand for Contraception Choices stimulated a design change from a feasibility to an efficacy trial, with follow-up for clinical outcomes at 3 and 6 months. A randomisation list was incorporated into the trial software program to allocate participants to the intervention (website) or control group (standard care). / Intervention: Contraception Choices is a co-designed, evidence-based, interactive website to aid informed choice of contraception. It provides information about different methods, addresses common concerns and offers tailored contraceptive options in response to individual preferences. / Main outcome measures: Qualitative – participant views and experience of the intervention, assessed through qualitative interviews. Quantitative primary outcomes – follow-up rate at 6 months in the initial feasibility trial, using a long-acting reversible contraception method, and satisfaction with contraceptive method at 6 months in the efficacy trial. / Results: A total of 927 women were randomised online to the website (n = 464) or control group (n = 463), of whom 739 (80%) provided follow-up data at 6 months [786 women (85%) provided data at 3 and/or 6 months that were included in the analysis of primary outcomes]. There was little difference between groups in the proportion using long-acting reversible contraception at 6 months [30.4% intervention vs. 31.0% control, adjusted odds ratio after imputation 0.87 (95% confidence interval 0.60 to 1.27)] or in satisfaction with contraceptive method [proportion being ‘satisfied’ or ‘very satisfied’, 82.6% intervention vs. 82.1% control, adjusted odds ratio 0.93 (95% confidence interval 0.69 to 1.25)]. Qualitative evaluation indicated highly positive views about the website and increased knowledge of contraceptive methods that could dispel misperceptions. Women appreciated having information tailored to their specific needs and felt better prepared before consultations. / Limitations: We did not include intermediate measures, such as knowledge of contraceptive methods, intention to change method or confidence in discussing contraception with a health-care professional, which may have indicated other benefits of using the website. In future, the website should be studied in different settings (e.g. schools and in routine practice) to see whether or not it improves the quality or efficiency of contraceptive consultations. / Conclusions: Our systematic review indicated wide-ranging influences on women’s use of contraception globally. The website, Contraception Choices, was very popular with young women and contraception service providers. It was not associated with statistically significant differences in use of long-acting reversible contraception or satisfaction with contraceptive method at 6 months. / Trial registration: Current Controlled Trials ISRCTN13247829. / Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 56. See the NIHR Journals Library website for further project information