Design of microwave heating equipment for laboratory applications

Includes bibliographical references.General purpose pressure vessels for digestion in microwave ovens have been developed and their applications investigated. The vessels were manufactured from PTFE and polypropylene and included a safety valve. The easily manufactured vessels were found to be reliable for a wide range of samples. A small vessel of 10 ml capacity, also constructed from PTFE and polypropylene, was developed for very small samples. These were used for the digestion of blood. A design for a simple modification of microwave ovens for use in the laboratory has been investigated. A Sharp microwave oven was lined with polypropylene and an extraction system that worked by the Venturi effect was used to remove the fumes from the cavity of the oven. This modification was found to be adequate to prevent corrosion of the oven and to provide the necessary safety features required for a laboratory system. In another modification, a thermocouple and a controller were used for maintaining the temperatures of the samples. Ports were available at the top of the cavity for insertion of suitable vessels for a variety of investigations. A computer-controlled waveguide has been designed for general laboratory applications. The temperature of the samples could be monitored and controlled. The waveguide was used for investigating sample digestions and the heating characteristics of a wide range of materials. A cylindrical applicator has been developed for the microwave heating of large (ca. 300- 600 ml) samples. Temperature monitoring and control was achieved through the use of a thermocouple and a computer. The instrument was found useful for many laboratory investigations involving relatively large samples. A new applicator has been developed for the even heating of multiple laboratory samples. The vessels (tubes) were introduced into the multimode cavity through ports. A choke was developed to allow rotation of the ports and the samples inside the cavity. Vapours could be extracted from the vessels outside the cavity using a fume extraction system. This system was found to be safe in terms of microwave leakages and yielded very good evenness of heating

Photoproduction of pi+ pi- pairs in a model with tensor-pomeron and vector-odderon exchange

We consider the reaction (gamma p) to (pi+ pi- p) at high energies. Our description includes dipion production via the resonances rho, omega, rho-prime and f2, and via non-resonant mechanisms. The calculation is based on a model of high energy scattering with the exchanges of photon, pomeron, odderon and reggeons. The pomeron and the C=+1 reggeons are described as effective tensor exchanges, the odderon and the C=-1 reggeons as effective vector exchanges. We obtain a gauge-invariant version of the Drell-Soeding mechanism which produces the skewing of the rho-meson shape. Starting from the explicit formulae for the matrix element for dipion production we construct an event generator which comprises all contributions mentioned above and includes all interference terms. We give examples of total and differential cross sections and discuss asymmetries which are due to interference of C=+1 and C=-1 exchange contributions. These asymmetries can be used to search for odderon effects. Our model is intended to provide all necessary theoretical tools for a detailed experimental analysis of elastic dipion production for which data exist from fixed target experiments, from HERA, and are now being collected by LHC experiments.Comment: 49 page

Peut-on prendre la mesure du risque silice ? Enquêtes santé, enquêtes travail et outils de veille sanitaire

La communication présente les champs de recherche, les sources, les méthodes et quelques premiers résultats du projet SILICOSIS piloté par Paul-André Rosental au Centre d’études européennes de Sciences Po, soutenu et financé par le Conseil européen de la recherche (European Research Council, ERC) pour la période 2012-2017. SILICOSIS est un projet de recherche qui fait collaborer étroitement l’histoire, la médecine, la statistique, la sociologie et l’épidémiologie. La silicose, pathologie causée par l’inhalation de silice cristalline, est la maladie professionnelle la plus mortelle de l’histoire (Rosental, 2008, 2013 ; Rosental, Devinck, 2007 ; Carnevale et al., 2012). Elle continue de causer des dégâts sanitaires considérables en lien avec les activités industrielles dans les pays développés mais aussi, de manière croissante, dans les pays émergents. Les travaux historiques montrent à quel point la silicose doit sa définition médicale même à des négociations impliquant, à partir des années 1930 et sous l’égide du Bureau international du Travail (BIT), des États, des syndicats d’employeurs et de salariés, des institutions chargées de la protection sociale. Ces travaux permettent de mieux comprendre les fondements du sous-repérage et de la sous-déclaration massifs de cette pathologie, en particulier du fait de confusions diagnostiques avec des maladies non reconnues comme d’origine professionnelle ou industrielle. La communication privilégie un aspect justifiant le caractère interdisciplinaire du projet : il s’agit d’interroger les classifications médicales contemporaines pour réévaluer la prévalence de la silicose aujourd’hui, en explorant des pistes de recherche qui mettent également au jour des mécanismes liés à l’exposition à la silice cristalline – et pas seulement par voie d’inhalation –, pour un ensemble de pathologies inflammatoires systémiques (Koeger et al., 1995) dont l’étiologie est inconnue et l’épidémiologie hétérogène. Ces pathologies (sarcoïdose (Vincent, Lièvre, 2002), lupus érythémateux disséminé (Parks et al., 2002), sclérodermie (Haustein, Ziegler, 1985), polyarthrite rhumatoïde par exemple), tout en étant rares si l’on retient le critère d’une prévalence inférieure à 1/2000, touchent plusieurs dizaines de milliers de personnes en France et sont, pour partie d’entre elles (polyarthrite rhumatoïde, lupus, sclérodermie), inscrites à la liste des affections de longue durée (ALD) exonérantes. À la question : « quelle est la prévalence, d’origine professionnelle ou non, de l’exposition à la silice cristalline, et quelle est la prévalence des pathologies – silicose mais pas seulement – qui en résultent ? », aucune source ne fournit le matériau d’une réponse exhaustive ou représentative de la population générale. C’est notamment ce manque que soulignent les travaux épidémiologiques et à visée de surveillance sanitaire qui débouchent sur la construction de « matrices emplois-expositions » centrées sur les expositions professionnelles à l’inhalation de silice cristalline (Delabre et al., 2010 ; Groupe de travail Matgéné, 2010 ; Luce et al., 2007 ; Luce et al., 2006). L’équipe du projet SILICOSIS se propose de rassembler et de confronter des sources qui, imparfaites ou partiellement aveugles sur la question à traiter, diverses par la nature des données qu’elles fournissent et les méthodes d’analyse qu’elles mettent en oeuvre, peuvent collaborer de façon dynamique : enquête statistique et historique sur archives ; travail qualitatif par entretiens et montage d’une enquête statistique en ligne auprès de médecins pour évaluer les pratiques diagnostiques et de prise en charge ; recherches médicales menées dans le laboratoire de minéralopathologie de l’hôpital saint-Joseph-saint Luc de Lyon ; enquêtes statistiques « santé » et « travail » françaises mesurant les liens entre santé et travail sous des angles qui s’ignorent souvent mutuellement (Cavalin & Célérier, 2012a) ; données administratives de santé. Celles-ci (données du Système national d’information inter-régimes de l’assurance maladie – SNIIRAM – ou du Programme de médicalisation des systèmes d’information – PMSI) permettent, au moins à des fins de cadrage et dans un domaine où les prévalences sont faibles, de tester des hypothèses sur des échantillons exhaustifs

Burden, timing and causes of maternal and neonatal deaths and stillbirths in sub-Saharan Africa and South Asia: Protocol for a prospective cohort study

OBJECTIVES: The AMANHI mortality study aims to use harmonized methods, across eleven sites in eight countries in South Asia and sub–Saharan Africa, to estimate the burden, timing and causes of maternal, fetal and neonatal deaths. It will generate data to help advance the science of cause of death (COD) assignment in developing country settings. METHODS: This population–based, cohort study is being conducted in the eleven sites where approximately 2 million women of reproductive age are under surveillance to identify and follow–up pregnancies through to six weeks postpartum. All sites are implementing uniform protocols. Verbal autopsies (VAs) are conducted for deaths of pregnant women, newborns or stillbirths to confirm deaths, ascertain timing and collect data on the circumstances around the death to help assign causes. Physicians from the sites are selected and trained to use International Classification of Diseases (ICD) principles to assign CODs from a limited list of programmatically–relevant causes. Where the cause cannot be determined from the VA, physicians assign that option. Every physician who is trained to assign causes of deaths from any of the study countries is tested and accredited before they start COD assignment in AMANHI. IMPORTANCE OF THE AMANHI MORTALITY STUDY: It is one of the first to generate improved estimates of burden, timing and causes of maternal, fetal and neonatal deaths from empirical data systematically collected in a large prospective cohort of women of reproductive age. AMANHI makes a substantial contribution to global knowledge to inform policies, interventions and investment decisions to reduce these deaths

The deep-sea macrobenthos on the continental slope of the northwestern Mediterranean Sea: a quantitative approach

As part of the ECOMARGE operation (J.G.O.F.S. France), macrobenthic assemblages in the Toulon Canyon were described and quantified on the basis of sampling carried out between 250 and 2000 m depth on the Mediterranean continental slope. Results show that Mediterranean bathyal assemblages are made up mainly of continental shelf eurybathic species. The qualitative and quantitative composition of populations varies with depth on the slope and also varies with station position at equivalent depth, whether on the flanks or in the canyon channel. Various analyses have provided evidence on the factors responsible for this population distribution pattern. No single factor emerges as predominant, but rather a group of factors, which are related to the nature and origin of sediments and more particularly their grain size distribution, geochemical composition and mode of transportation and sedimentation (benthic nepheloid or originating from the water column), act in conjunction to determine the pattern. Comparison with ocean continental slopes shows that in the Mediterranean Sea the absence of tidal current modifies the trophic structure of the macrobenthic assemblages, which are characterized by a dominance of surface and subsurface deposit feeders as compared to a dominance of suspension feeders and carnivores in the upper and median part of the slope in the ocean. Surface dumping of dredge spoil at the canyon head and channelling of waste induces an increase of organic matter and pollutant concentrations in sediment from the upper part of the canyon channel but does not give rise to any marked population degradation

Exhaust emissions of regulated and unregulated pollutants of passenger cars

Exhaust emissions of VOC speciation, aldehydes and other carbonyl compounds, polyaromatics and regulated pollutants are measured using a vehicle bench on a sample of passenger cars. 30 diesel and gasoline cars are tested, complying with ECE 1504 to Euro 3 emission standards, according to 10 real-world driving cycles based on European driving behaviour, with some of them adapted to vehicle size. The emission results of this large-scale measurement campaign show the influence of vehicle technology and driving behaviour on the emission of 100 individual pollutants. In addition, the results are discussed per VOC group and compared with other studies. The influence of the successive emission standards on the emission factors is very positive in most of cases. However, whereas hot CO2 is almost stable, diesel hot NOx, diesel hot and cold VOC, and the 6 most carcinogenic gasoline PAH have increased with standards. Diesel vehicles are less pollutant for CO, HC, CO2, VOC, but more pollutant for NOx and PAH. The distribution of VOC species per molecular family highlights the fact that monoaromatics make up the biggest share (~88 and 62 % resp. for gasoline and diesel vehicles). The second family is the alkanes which contribute resp. 8 and 9% of the total mass of measured VOC. The majority of volatile PAH is observed in the gaseous phase, but the least volatile and the carcinogenic PAH are adsorbed more in particulate phase