Thermal oxydation during extrusion of polyolefins

International audienceThe thermal oxidation during extrusion of polyethylene was studied under inert gas (nitrogen and CO2) and compared with extrusion under air atmosphere. A strong reduction of degradation rate was found by optical observation and by infrared analyses. A mechanism for the change of color is proposed

Air-fuel-ratio control of engine system with unknown input observer

This paper presents an alternative control to maintain the air-fuel-ratio (AFR) of port-injected spark ignition (SI) engines at certain value, i.e. stoichiometric value, to improve the fuel economy. We first reformulate the AFR regulation problem as a tracking control for the injected fuel mass flow rate, which can simplify the control synthesis when the fuel film dynamics are taken into account. The unknown engine parameters and dynamics can be lumped as an unknown signal, and then compensated by incorporating the unknown input observer into the control design. Only the measurable air mass flow rate through throttle, manifold pressure and temperature, and the universal exhaust gas oxygen (UEGO) sensor are utilized. Simulations based on a mean-value engine model (MVEM) illustrate that the proposed control can achieve satisfactory transient and steady-state performance with strong robustness when the engine is operated in varying speed conditions

Congenital coronary artery anomalies silent until geriatric age: non-invasive assessment, angiography tips, and treatment

Coronary artery anomalies (CAAs) may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, functional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs: computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional significance is mandatory for deciding how to manage CAAs: non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities

Classifying radius fractures with X-ray and tomography imaging

INTRODUÇÃO: Este estudo avaliou a confiabilidade interobservador da radiografia simples versus tomografia computadorizada para as classificações Universal e AO em fraturas do rádio distal. PACIENTES e MÉTODOS: Cinco observadores classificaram 21 fraturas do rádio distal utilizando radiografias e tomografias independentemente. O índice Kappa foi utilizado para estabelecer o nível de concordância entre os observadores. RESULTADOS: A confiabilidade interobservador da classificação Universal foi moderada e a confiabilidade interobservador da classificação AO foi baixa. Reduzindo a clas-sificação AO a nove categorias e às três categorias básicas houve melhora do nível de confiabilidade para "moderado". Não houve diferença entre a confiabilidade interobservador da classificação Universal baseada em imagens radiográficas em comparação com a classificação Universal baseada em imagens tomográficas. A confiabilidade interobservador da classificação AO baseada em radiografias simples foi significativamente maior que a confiabilidade interobservador da classificação AO baseada apenas em tomografias computadorizadas. CONCLUSÃO: A partir destes dados, concluímos que classificar fraturas do rádio distal utilizando tomografias computadorizadas sem o auxílio das radiografias simples não traz benefício.INTRODUCTION: This study evaluated the interobserver reliability of plain radiograpy versus computed tomography (CT) for the Universal and AO classification systems for distal radius fractures. PATIENTS AND METHODS: Five observers classified 21 sets of distal radius fractures using plain radiographs and CT independently. Kappa statistics were used to establish a relative level of agreement between observers for both readings. RESULTS: Interobserver agreement was rated as moderate for the Universal classification and poor for the AO classification. Reducing the AO system to 9 categories and to its three main types reliability was raised to a "moderate" level. No difference was found for interobserver reliability between the Universal classification using plain radiographs and the Universal classification using computed tomography. Interobserver reliability of the AO classification system using plain radiographs was significantly higher than the interobserver reliability of the AO classification system using only computed tomography. CONCLUSION: From these data, we conclude that classification of distal radius fractures using CT scanning without plain radiographs is not beneficial

Use of gastrocnemius muscle on treatment of infected injuries of the knee

OBJETIVO: Avaliar prospectivamente o emprego do retalho do músculo gastrocnêmio no tratamento de lesões infectadas do joelho. MÉDOTOS: foram operados 12 pacientes, onze do sexo masculino, com idade variando de 19 a 78 anos, média de 55 anos. A cobertura com músculo gastrocnêmio medial foi realizada em 11 pacientes, e lateral em um. A média de desbridamentos pré-operatórios foi de 3,2 procedimentos, variando de um a nove. RESULTADOS: todos os retalhos sobreviveram. O agente etiológico mais comum foi o S. aureus, em 54,5%. Após seguimento médio de 20,08 meses (13 a 31), todos os pacientes apresentam cobertura estável sem sinais ou sintomas de reinfecção. CONCLUSÃO: a utilização do músculo gastrocnêmio no tratamento de lesões infectadas do joelho proporcionou bons resultados com baixa morbidade.OBJECTIVE: to prospectively evaluate the use of gastrocnemius muscle flap in the treatment of knee infected injuries. METHODS: twelve patients were operated on: eleven males with ages ranging from 19 to 78 years, mean: 55 years. Coverage of injuries with medial gastrocnemius muscle was accomplished in 11 patients and a lateral in 1. The mean number of preoperative surgical debridement procedures was 3.2, ranging from 1 to 9. RESULTS: all flaps survived. The most common etiological agent was S. aureus, in 54.5%. After a mean follow-up of 20.08 months (13 to 31), all patients show stable coverage without recurrence of infection signs or symptoms. CONCLUSION: gastrocnemius muscle use in knee infected injuries treatment presented good results and low morbity rates

Characterizing early cancer biology through multiplexed and multiscale super-resolution microscopy technique development

This thesis work highlights technique development and emerging applications for improving super-resolution microscopy (SRM) throughput, analysis and applications in studying early cancer biology

A Classification Model for Reusable Software Components

TIris paper presents work which has been carried out in the ESF-ROSE project (referred to as ROSE in the remainder of this paper). Funded under the Eureka programme (Eureka is the famous interjection used by Archimedes in his bath and not an acronym), the ESF project (Eureka Software Factory) aims at providing a highly effective software manufacturing environment The use of the wordfactory in the software context has very little connection to traditional assemblyline factories. Instead, a Software Factory is a factory in the modem sense providing Computer Integrated Software Manufacturing with emphasis on integration. A software factory covers the total software production process, including all technical and managerial tasks, with a high degree of automation and resource utilization. The ROSE project is a collaborative effon involving MATRA Espace, the software house Serna Group (France), and the University of Dortmund (Federal Republic of Gennany). Pan of the work on classification is the Ph.D. research of author Eric Rames. The main goals of the ROSE project (Reuse Of SoftwarE) are: • to analyze and to define in a comprehensive way the concept of software reuse; • to develop an environment for the reuse of software components within a factory. A precondition for reuse in software development is the existence of libraries of reusable software components. In order to suppon reuse, the collection must contain not only the components themselves, but also be accessible by a system that provides descriptions of the components and retrieval mechanisms so that users may match their specific requirements against these descriptions. Indexing reusable software components according to a classification scheme allows reusers to have a better understanding and more efficient access to the libraries' contents. Therefore a classification scheme is built so that it represents selection criteria the reuser might have. These indexes would be searchable and keyed to retrievable software descriptions. Based on retrievals, users may then access the actual software. Building such a collection is a domain analysis process [PRI90] that includes activities such as: • Identification of software components that should be reusable and description in terms of reusable software components. • Definition of a classification scheme appropriate for indexing and retrieving the reusable software components. TIris paper focuses on the latter topic and how it is performed in the ROSE project. A case study carried out from the aerospace domain is then presented. A discussion of ongoing and future work will conclude this paper

Simulation of Bose-Einstein effect using space-time aspects of Lund string fragmentation model

The experimentally observed enhancement of number of close boson pairs in e+e- collisions is reproduced by local weighting according to the quantum mechanical prescriptions for production of identical bosons. The space-time picture of the process, inherently present in the Lund fragmentation model, is explicitly used. The model is used to check systematic errors in the W mass measurements due to the Bose-Einstein effect. The possibility of direct implementation of the Bose-Einstein effect into string fragmentation is discussed.Comment: 26 pages, Latex, 17 figures in PS format attache