334 research outputs found

    Status of evaluated data files for 238U in the resonance region

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    Experimental data and evaluated data libraries related to neutron induced reaction cross sections for 238U in the resonance region are reviewed. Based on this review a set of test files is produced to study systematic effects such as the impact of the upper boundary of the resolved resonance region (RRR) and the representation of the infinite diluted capture and in-elastic cross section in the unresolved resonance region (URR). A set of Benchmark experiments was selected and used to verify the test files. Based on these studies recommendations to perform a new evaluation have been defined. This report has been prepared in support to the CIELO (Collaborative International Evaluated Library Organisation) project. The objective of this project is the creation of a world-wide recognised nuclear data file with a focus on six nuclides, i.e. 1H, 16O, 56Fe, 235U, 238U and 239Pu. Within the CIELO project, the Joint Research Centre (JRC) at Geel (B) is in charge of the production of an evaluated cross section data file for neutron induced reaction of 238U in the resonance region.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

    Experience of phototherapy in dermatological praxis in complex therapy of psoriasis patients

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    Publisher Copyright: © 2016 Ilona Hartmane et al., published by De Gruyter Open 2016.Psoriasis is a chronic relapsing skin disease presenting with erythematous and papulous lesions with infiltration and extensive desquamation on the skin surface. It is a genetically determined, multifactorial dermatosis where genetic, immune, and environmental factors play significant roles in its development. In Latvia in treatment of different forms of extensively spreading psoriasis, PUVA (psoralen and ultraviolet A light therapy), a combined method, is administered, applying long-wave UVA radiation with wavelength 320-400 nm in combination with photosensibilisator 8-metoxypsoralen and medium wave length UVB radiation narrow-band phototherapy - 311 nm using specialised TL-01 lamps. The aim of our clinical investigation was to determine the efficacy of narrow-band phototherapy (UVB 311 nm) in the complex treatment of patients with different severity of extensive psoriatic lesions treated in the Clinical Centre of Skin and Sexually Transmitted Diseases. Cases of clinical data of 260 patients with widely spread psoriasis were analysed. In the Group 1 (n = 102) receiving narrow-band UVB therapy, the mean and cumulative UVB dosage was 1.8 ± 0.6 and 21.5 ± 3.8 J/cm2, respectively, whereas in Group 2 (n = 91) it was 2.2 ± 0.1 and 27.7 ± 8.0 J/cm2. To obtain clinical recovery, 18 to 30 procedures were necessary (average 22 ± 4.1) with total irradiation dose received 110 ± 4.6 J/cm2. In 67 patients of the control group, PUVA therapy was administered, and positive therapeutic efficacy was observed in all patients. Clinical recovery was obtained in 86.2% in patients of the Group 1, in 82.4% - of Group 2, and in 80% - in 67 patients of the control group. Narrow-band (311 nm) UVB phototherapy is currently one of the leading pathogenetical methods of treatment of patients with widespread psoriasis. It has high efficacy, good tolerability, does not have severe side effects and restrictions in use, in comparison with traditional PUVA therapy.publishersversionPeer reviewe

    A Perspective on the Use of NB-UVB Phototherapy vs. PUVA Photochemotherapy

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    Narrowband UVB (NB-UVB) phototherapy and psoralen-UVA (PUVA) photochemotherapy are widely used phototherapeutic modalities for a range of skin diseases. The main indication for NB-UVB and PUVA therapies is psoriasis, and other key diagnoses include atopic eczema, vitiligo, cutaneous T-cell lymphoma (CTCL), and the photodermatoses. The decision on choice of phototherapy is important and NB-UVB is usually the primary choice. NB-UVB phototherapy is a safe and effective therapy which is usually considered when topical agents have failed. PUVA requires prior psoralen sensitization but remains a highly effective mainstay therapy, often used when NB-UVB fails, there is rapid relapse following NB-UVB or in specific indications, such as pustular or erythrodermic psoriasis. This review will provide a perspective on the main indications for use of NB-UVB and PUVA therapies and provide comparative information on these important dermatological treatments

    On the use of Bayesian Monte-Carlo in evaluation of nuclear data

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    As model parameters, necessary ingredients of theoretical models, are not always predicted by theory, a formal mathematical framework associated to the evaluation work is needed to obtain the best set of parameters (resonance parameters, optical models, fission barrier, average width, multigroup cross sections) with Bayesian statistical inference by comparing theory to experiment. The formal rule related to this methodology is to estimate the posterior density probability function of a set of parameters by solving an equation of the following type: pdf(posterior) ∼ pdf(prior) × a likelihood function. A fitting procedure can be seen as an estimation of the posterior density probability of a set of parameters (referred as x→) knowing a prior information on these parameters and a likelihood which gives the probability density function of observing a data set knowing x→. To solve this problem, two major paths could be taken: add approximations and hypothesis and obtain an equation to be solved numerically (minimum of a cost function or Generalized least Square method, referred as GLS) or use Monte-Carlo sampling of all prior distributions and estimate the final posterior distribution. Monte Carlo methods are natural solution for Bayesian inference problems. They avoid approximations (existing in traditional adjustment procedure based on chi-square minimization) and propose alternative in the choice of probability density distribution for priors and likelihoods. This paper will propose the use of what we are calling Bayesian Monte Carlo (referred as BMC in the rest of the manuscript) in the whole energy range from thermal, resonance and continuum range for all nuclear reaction models at these energies. Algorithms will be presented based on Monte-Carlo sampling and Markov chain. The objectives of BMC are to propose a reference calculation for validating the GLS calculations and approximations, to test probability density distributions effects and to provide the framework of finding global minimum if several local minimums exist. Application to resolved resonance, unresolved resonance and continuum evaluation as well as multigroup cross section data assimilation will be presented

    Identification de résines végétales datant de l'Egypte ancienne par Chromatographie en phase gazeuse couplée à un spectromètre de masse

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    Trois échantillons, respectivement référencés L24, L42 et L36 provenant de la collection Victor Loret de l'Institut d'Egyptologie (Université Lyon II, Pr J.-C. Goyon), ont été analysés. Ils ont été prélevés lors de fouilles effectuées par l'archéologue J. de Morgan sur le site de Dashour dans les années 1894 et 1895. L'analyse de ces matériaux, menée par Chromatographic en Phase Gazeuse couplée à un Spectromètre de Masse (CPG/SM), a mis en évidence l'existence de véritables formulations. Le prélèvement L24 a été identifié comme étant un mélange constitué d'une résine appartenant à la famille des Ombellifères et plus précisément au genre Ferula, d'un corps gras ainsi que d'une résine de conifère.Three samples, respectively referred L24, L42 and L36 coming from the collection Victor Loret of the Egyptologic Institute (University Lyon II, Pr J.-C. Goyon), were analyzed. They were recovered from excavations at Dashour in 1894-1895 by the archaeologist J. de Morgan. The analysis of these materials carried out by Gas Chromatography coupled to a Mass Spectrometer (GC/MS) and the results show the existence of real formulations. L24 was identified as a mixture of a resin belonging to the family of Umbellifereae and more precisely to the Ferula genus, a fatty substance and a resin of conifer
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