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Alloy X-750 was exposed to a 480 °C CO-CO 2 reducing gas mixture at an oxygen partial pressure below the NiO dissociation pressure. Post-exposure analytical transmission electron microscopy (ATEM) analysis confirmed the occurrence of preferential intergranular oxidation (PIO) and internal oxidation which resulted in the formation of Ni nodules. Thus, reducing CO-CO 2 mixtures can promote PIO in Alloy X-750, similar to Alloy 600 exposed to similar oxygen partial pressure but in H 2 -steam environment. In Alloy X-750, intergranular oxidation of Ti and Al were observed to occur prior to Cr oxidation, while the presence of intergranular Cr carbides hinders PIO penetration depth. • CO-CO2 mixtures can promote internal and intergranular oxidation in X-750. • Results are similar to observed in Alloy 600 exposed to H2-steam. • Intergranular oxidation front is led by Ti and Al. [ABSTRACT FROM AUTHOR]

Oxidation experiments on Alloy X-750 were performed in reducing CO-CO 2 mixtures to assess the possibility of preferential intergranular oxidation (PIO) in relation to CANDU garter-spring spacers. The testing environments simulate hypothetical off-chemistry scenarios, promoting the oxidation of the alloying elements, but not Ni. Surface and cross-section microscopy corroborated by Auger electron spectroscopy confirmed the occurrence of internal and intergranular oxidation in Alloy X-750, accompanied by Ni nodule expulsion to the surface. Results are qualitatively similar to observations in Alloy 600 exposed to 480°C hydrogenated steam, used as an accelerated environment for primary water stress corrosion cracking (PWSCC) testing. [ABSTRACT FROM AUTHOR]

Solution-annealed Alloy 600 samples were tested under active load conditions in a superheated low pressure H 2 -steam environment over a range of oxidising potentials relevant to Primary Water Stress Corrosion Cracking (PWSCC). Increased SCC susceptibility was observed for potentials the more reducing than the Ni/NiO transition where a deeper Preferential Intergranular Oxidation (PIO) occurred. Advanced microstructural analysis clearly showed that SCC initiated along the grain boundaries that exhibited Diffusion-Induced Grain Boundary Migration (DIGM), as well as enrichments in Al and Ti. Rather than the result of a single dominant mechanism, the initiation of SCC in Ni-base alloys involves the synergistic interactions between DIGM and the formation of Al- and Ti-enriched oxides, promoting PIO that can fracture with applied stress. Image, graphical abstract [ABSTRACT FROM AUTHOR]

This present work introduces a new understanding of the precursors events to Stress Corrosion Cracking (SCC) initiation in nuclear power plant components, exploring the role of grain boundary migration and Preferential Intergranular Oxidation (PIO). In this work, a systematic evaluation of Alloy 600 exposed in low pressure H 2 -steam over a range of oxidizing potentials in the vicinity of the Ni/NiO transition has revealed a notable decrease in PIO for conditions more oxidizing than the Ni/NiO transition, whilst local diffusion-induced grain boundary migration occurs irrespective of the oxidizing potential. Thus, grain boundary migration in itself is not a unique signature for PIO and SCC incubation, but it is necessary for the development of PIO and it represents a critical acceleration factor for more reducing conditions (such as those in pressurised water reactors) where oxide film instability allows for the initiation of PIO. It is also shown that Al/Ti enrichments that develop along the migrated GBs correlate with the occurrence of PIO when the alloy develops a non-protective external oxide. Image 1 [ABSTRACT FROM AUTHOR]

Thermally-treated Alloy 600 coupons were tested in pressurized water reactor simulated primary water at 320 °C and in high-pressure superheated steam at 400 °C to study the effect of a "semi-continuous" network of intergranular carbides on the stress corrosion cracking "precursors events": preferential intergranular oxidation (PIO) and diffusion-induced grain boundary migration (DIGM). The intergranular carbides were partially consumed due to the environmental exposure, whereby the Cr released from the carbides contributed to the formation of the external oxide layer that limited both PIO and DIGM. The results were compared with previous studies in which similar coupons were exposed to H 2 -steam. • Thermally-treated Alloy 600 was exposed to PWR simulated primary water and high pressure steam. • Thermally-treated Alloy 600 is susceptible to intergranular oxidation. • The intergranular Cr-rich M 7 C 3 carbides were susceptible to decomposition • Carbide decomposition provides Cr for the formation of a dense surface Cr 2 O 3. • The oxidation behaviour is comparable to that observed in superheated H 2 -steam. [ABSTRACT FROM AUTHOR]

Abstract: Generation of high intensity and well collimated multi-energetic proton beams from laser–matter interaction extends the possibility to use protons as a diagnostic tool to image imploding target in Inertial Confinement Fusion (ICF) experiments. Due to the very large mass densities reached during implosion, protons traveling through the target undergo a very large number of collisions. Therefore the analysis of experimentally obtained proton images requires care and accurate numerical simulations using both hydrodynamic and Monte Carlo codes. The impact of multiple scattering needs to be carefully considered by taking into account the exact stopping power for dense matter and for the underdense plasma corona. In our paper, density, temperature and ionization degree profiles of the imploding target are obtained by 2D hydrodynamic simulations performed using CHIC code. Proton radiography images are simulated using the Monte Carlo code (MCNPX; adapted to correctly describe multiple scattering and plasma stopping power) in order to reconstruct the complete hydrodynamic history of the imploding target. Finally we develop a simple analytical model to study the performance of proton radiography as a function of initial experimental parameters, and identify two different regimes for proton radiography in ICF. [Copyright &y& Elsevier]

An experiment was done at the Rutherford Appleton Laboratory (Vulcan laser petawatt laser) to study fast electron propagation in cylindrically compressed targets, a subject of interest for fast ignition. This was performed in the framework of the experimental road map of HiPER (the European high power laser energy research facility project). In the experiment, protons accelerated by a picosecond-laser pulse were used to radiograph a 220 μm diameter cylinder (20 μm wall, filled with low density foam), imploded with ∼200 J of green laser light in four symmetrically incident beams of pulse length 1 ns. Point projection proton backlighting was used to get the compression history and the stagnation time. Results are also compared to those from hard x-ray radiography. Detailed comparison with two-dimensional numerical hydrosimulations has been done using a Monte Carlo code adapted to describe multiple scattering and plasma effects. Finally we develop a simple analytical model to estimate the performance of proton radiography for given implosion conditions. [ABSTRACT FROM AUTHOR]

Abstract: A three dimensional, time dependent, quantum model for an FEL with a laser wiggler, based on a discrete Wigner function formalism taking into account the longitudinal momentum quantization, is presented. Starting from the exact quantum treatment, a motion equation for the Wigner function coupled to the self-consistent radiation field is derived in the realistic limit in which the normalized electron beam emittance is much larger than the Compton wavelength quantum limit. The model describes the three-dimensional spatial and temporal evolution of the electron and radiation beams, including diffraction, propagation, laser wiggler, emittance and quantum recoil effects. It can be solved numerically and reduces to the three-dimensional Maxwell–Vlasov model in the classical limit. We discuss the experimental requirements for a quantum X-ray FEL with a laser wiggler, presenting preliminary numerical results and parameters for a possible future experiment. [Copyright &y& Elsevier]

In order to evaluate the prevalence of gestational diabetes mellitus (GDM) and the presence of risk factors for GDM, we conducted a retrospective study of a cohort of Italian women. In addition, we compared universal versus selective screening to validate the ADA''s recommendations in our population. From June 1st, 1995 to December 31st, 2001, universal screening for GDM was performed in 3950 women. The glucose challenge test (GCT) was positive (GCT+) in 1389 cases (35.2%). The 1-h glucose level after GCT enabled us to diagnose GDM directly in 24 pregnant women. Oral glucose tolerance test (OGTT) was performed in 1221 GCT+ women (144 cases with GGT+ dropped out) and GDM was diagnosed in 284 (23.2%) of them. OGTT was also performed in 391 randomly chosen, women from the GCT negative (GCT−) group. In this last group 25 (6.3%) women had GDM. Thus, the total number of subjects with GDM was 333 out of 3806 with a prevalence of 8.74% in the entire cohort. Assuming that the rate of GDM observed in the random sample of GCT− women is applicable to the whole group of 2561 GCT− women, then 161 GCT− patients could also have GDM. This will further increase the estimated prevalence for the whole cohort up to 12.3% (i.e. 469 out of 3806 pregnant women). There were 236 (5.6%) women with a low risk for GDM (normal weight, age less than 25 years and without a family history of diabetes). In this group we found 34 cases and five cases with positive screening test and GDM, respectively. Thus, if we excluded low risk women from the screening test, as suggested by ADA recommendations, only five women with GDM would have been missed. However, about 95% of our population were at medium or high risk for GDM and, therefore, would have been screened. The rate of GDM was significantly higher in women with a positive history of diabetes, increasing age, previous pregnancies, pre-pregnancy overweight and short stature. After logistic regression analysis, GDM diagnosis was significantly correlated with age (P<0.0001), pre-pregnancy BMI (P<0.0001), weight gain (P<0.0001) and family history of diabetes (P<0.01). [Copyright &y& Elsevier]

• Machining processes affect the near surface region microstructure of A182. • Machining processes affect the EAC initiation threshold stress of A182 in BWR. • The machining-induced deformation structure affect the EAC initiation and growth. • The EAC initiation susceptibility at 1 × 10−7 s−1 shows that SP > STI > RS > SAM. The effects of four machining surface preparations on the environmentally-assisted cracking (EAC) initiation and early crack growth were evaluated for Alloy 182 flat tapered specimens exposed to a simulated boiling water reactor (BWR) environment under constant extension rate tensile test conditions. Results showed that the apparent EAC critical threshold stress for initiation was highly dependent on the surface treatment. Detailed microstructural characterization revealed the nature of the machining-induced deformation associated with the four surface treatments. Surface treatments affected the surface oxidation during exposure in the simulated BWR environment. The machining-induced deformation structure affected the EAC initiation susceptibility. [ABSTRACT FROM AUTHOR]

• Alloy 690SA and Alloy 690 T T exhibited similar oxidation behaviour in H 2 -steam. • A surface Cr 2 O 3 layer limited preferential intergranular oxidation on Alloy 690. • Diffusion-induced grain boundary migration occurred in both TT and SA conditions. • Al and Ti enrichments were detected on the surface of the newly migrated area. Oxidation experiments were performed on Alloy 690 in a low pressure H 2 -steam environment at 480 °C to investigate the effects of the microstructure and thermal treatment on the "precursors events" associated with Primary Water Stress Corrosion Cracking. Advanced analytical electron microscopy characterisation revealed that the Alloy 690 did not exhibit preferential intergranular oxidation but rather only diffusion-induced grain boundary migration promoted by the formation of an external Cr 2 O 3 oxide layer for both material conditions (solution-annealed vs. thermally-treated). These data demonstrate that for Alloy 690 the diffusion-induced grain boundary migration is a necessary but not sufficient condition for preferential intergranular oxidation. [ABSTRACT FROM AUTHOR]

Comments on the impact of multiproduct and multimarket managed care plans on the health care market in the United States. Competition in such market environments; Purchasing of coverage by individual and group buyers; Distribution channels of health plans; Market response to consumers' needs in the future.

Using one-dimensional, long-timescale particle-in-cell simulations, we study the processes of ion acceleration from the interaction of ultraintense ( 10 20 W cm − 2 ), ultrashort (30 fs) laser pulses with near-critical, nonuniform gas targets. The considered initially neutral, nitrogen gas density profiles mimic those delivered by an already developed noncommercial supersonic gas shock nozzle: they have the generic shape of a narrow (20 μ m wide) peak superimposed on broad (∼1 mm, ∼ 180 μ m scale length), exponentially decreasing ramps. While keeping its shape constant, we vary its absolute density values to identify the interaction conditions leading to collisionless shock-induced ion acceleration in the gas density ramps. We find that collisionless electrostatic shocks (CES) form when the laser pulse is able to shine through the central density peak and deposit a few 10% of its energy into it. Under our conditions, this occurs for a peak electron density between 0.35 n c and 0.7 n c . Moreover, we show that the ability of the CES to reflect the upstream ions is highly sensitive to their charge state and that the laser-induced electron pressure gradients mainly account for shock generation, thus highlighting the benefit of using sharp gas profiles, such as those produced by shock nozzles. [ABSTRACT FROM AUTHOR]

Shock Ignition is a two-step scheme to reach Inertial Confinement Fusion, where the precompressed fuel capsule is ignited by a strong shock driven by a laser pulse at an intensity in the order of 10 16 W/cm 2 . In this report we describe the results of an experiment carried out at PALS laser facility designed to investigate the origin of hot electrons in laser-plasma interaction at intensities and plasma temperatures expected for Shock Ignition. A detailed time- and spectrally-resolved characterization of Stimulated Raman Scattering and Two Plasmon Decay instabilities, as well as of the generated hot electrons, suggest that Stimulated Raman Scattering is the dominant source of hot electrons via the damping of daughter plasma waves. The temperature dependence of laser plasma instabilities was also investigated, enabled by the use of different ablator materials, suggesting that Two Plasmon Decay is damped at earlier times for higher plasma temperatures, accompanied by an earlier ignition of SRS. The identification of the predominant hot electron source and the effect of plasma temperature on laser plasma interaction, here investigated, are extremely useful for developing the mitigation strategies for reducing the impact of hot electrons on the fuel ignition. [ABSTRACT FROM AUTHOR]

Controlling the divergence of laser-driven fast electrons is compulsory to meet the ignition requirements in the fast ignition inertial fusion scheme. It was shown recently that using two consecutive laser pulses one can improve the electron-beam collimation. In this paper we propose an extension of this method by using a sequence of several laser pulses with a gradually increasing intensity. Profiling the laser-pulse intensity opens a possibility to transfer to the electron beam a larger energy while keeping its divergence under control. We present numerical simulations performed with a radiation hydrodynamic code coupled to a reduced kinetic module. Simulation with a sequence of three laser pulses shows that the proposed method allows one to improve the efficiency of the double pulse scheme at least by a factor of 2. This promises to provide an efficient energy transport in a dense matter by a collimated beam of fast electrons, which is relevant for many applications such as ion-beam sources and could present also an interest for fast ignition inertial fusion. [ABSTRACT FROM AUTHOR]

We studied the transport of an intense electron beam produced by high intensity laser pulses through metals and insulators. Targets were irradiated at two different intensities, 1017 W/cm2 and 1019 W/cm2, at the laser facility Xtreme Light XL-III in Beijing, a Ti:Sa laser source emitting 40 fs pulses at 800 nm. The main diagnostic was Cu-Kα fluorescence imaging. Images of Kα spots have been collected for those two laser intensities, for different target thickness, and for different materials. Experimental results are analyzed taking into account both collisional and collective effects as well as refluxing at the edge of the target. The target temperature is evaluated to be Tc ∼ 6 eV for intensity I = 1017 W/cm2 (for all the tested materials: plastic, aluminium, and copper), and Tc ∼ 60 eV in aluminium and 120 eV in titanium for intensity I = 1019 W/cm2. [ABSTRACT FROM AUTHOR]

The relativistic laser-driven electron transport in partially or fully ionized matter has been investigated in many recent experiments. The high laser intensity achievable today (up to 1020 W/cm2) allows to generate electron current density above 1011 A/cm2. In this regime, electromagnetic effects start to be dominant over collisional ones. In this context, we have developed a simple 2D model for the fast electron transport accounting for (1) electric effects on the electron penetration range and (2) the electron refluxing in thin foils. We compare our model with those existing in literature and with some recent experimental results on fast electron transport in matter. The model predicts a maximum value for the electron penetration range in the region where the collisional and the resistive effects are comparable. [ABSTRACT FROM AUTHOR]

This study characterizes the opacifiers and colouring agents used in the glazed bricks of Persepolis (mid-first millennium bc) and the Mannean site of Tepe Rabat in north-western Iran (eighth to seventh centuries bc). Various analytical studies show that lead antimonate and brizziite (NaSbO3) were used as the yellow and white opacifiers in the glazes of Persepolis and Tepe Rabat. Brizziite is shown to be incorporated in the white, green and turquoise glazes, and is also associated with lead antimonate and CaSb2O6 in some yellow and white opacifiers. The simultaneous formation of these opacifiers in one glaze might have been accidental. A possible connection between the Achaemenid glaze industry and the Mannean glaze production at Tepe Rabat is discussed. [ABSTRACT FROM AUTHOR]

Strong electromagnetic pulses (EMPs) are generated from intense laser interactions with solid-density targets and can be guided by the target geometry, specifically through conductive connections to the ground. We present an experimental characterization by time- and spatial-resolved proton deflectometry of guided electromagnetic discharge pulses along wires including a coil, driven by 0.5 ps, 50 J, 1019 W/cm2 laser pulses. Proton-deflectometry allows us to time-resolve first the EMP due to the laser-driven target charging and then the return EMP from the ground through the conductive target stalk. Both EMPs have a typical duration of tens of ps and correspond to currents in the kA-range with electric-field amplitudes of multiple GV/m. The sub-mm coil in the target rod creates lensing effects on probing protons due to both magnetic- and electric-field contributions. This way, protons of the 10 MeV-energy range are focused over cm-scale distances. Experimental results are supported by analytical modeling and high-resolution numerical particle-in-cell simulations, unraveling the likely presence of a surface plasma, in which parameters define the discharge pulse dispersion in the non-linear propagation regime. [ABSTRACT FROM AUTHOR]

Fluid targets are attractive for laser-driven ion acceleration at high-repetition-rate laser facilities. In particular, liquid targets have several interesting features since they can regenerate in situ and are debris-free (or little) and operate at a high repetition rate. Here, we report high-repetition-rate MeV-range proton acceleration by the interaction of the VEGA-2 laser system with a micrometer-thick water sheet target in a high vacuum (10âˆ'4 mbar) environment. The water target was running continuously at this pressure for 4 h and more than 1000 shots were performed. Two different water thicknesses were studied, and we measured a continuous proton distribution with energies up to 3.5 MeV. Experimental results are compared with the literature and existing scaling laws. [ABSTRACT FROM AUTHOR]

Fast ignition requires a precise knowledge of fast electron propagation in a dense hydrogen plasma. In this context, a dedicated HiPER (High Power laser Energy Research) experiment was performed on the VULCAN laser facility where the propagation of relativistic electron beams through cylindrically compressed plastic targets was studied. In this paper, we characterize the plasma parameters such as temperature and density during the compression of cylindrical polyimide shells filled with CH foams at three different initial densities. X-ray and proton radiography were used to measure the cylinder radius at different stages of the compression. By comparing both diagnostics results with 2D hydrodynamic simulations, we could infer densities from 2 to 11 g/cm3 and temperatures from 30 to 120 eV at maximum compression at the center of targets. According to the initial foam density, kinetic, coupled (sometimes degenerated) plasmas were obtained. The temporal and spatial evolution of the resulting areal densities and electrical conductivities allow for testing electron transport in a wide range of configurations. [ABSTRACT FROM AUTHOR]

Abstract: We derive a 1D quantum model for the free electron laser in terms of a Wigner function for the electron beam. We consider both the case of an unbounded space coordinate, for which the momentum is continuous, and the case of a periodic space coordinate, for which the momentum is discrete. The Wigner model extends the Schrödinger model, previously considered, since it also describes the evolution of a mixed state. Furthermore, the Wigner model shows explicitly the classical limit when the quantum FEL parameter is large. This model is also the starting point for a future extension to a 3D description of the electron dynamics. The results obtained here are also valid for the quantum description of the collective atomic recoil laser. [Copyright &y& Elsevier]

To determine the predictive value of serum triglyceride levels (TG) for neonatal weight in pregnant women with positive diabetic screening but normal glucose tolerance.We enrolled 180 pregnant Caucasian women with positive diabetic screening. All women underwent a 3-h 100-g oral glucose tolerance test (OGTT) at 27th ± 4 week of gestation. At the time of OGTT, we measured: fasting plasma glucose, fasting lipids profile and determined ApoE polymorphisms to evaluate the effects on lipid levels. In 83 women with normal glucose tolerance and at term delivery we evaluated the association between maternal serum TG, specific maternal parameters known to affect fetal growth and newborn weight.Based on OGTT, gestational diabetes mellitus (GDM) was diagnosed in 36 women (20%), impaired glucose tolerance (IGT) in 23 (13%), and normal glucose tolerance (NGT) in 121 (67%). Serum TG concentration was significantly higher in women with GDM (2.47 ± 0.77 mmol/l) as compared with NGT (1.99 ± 0.64 mmol/l) or IGT (1.98 ± 0.81 mmol/l) (P < 0.01). ApoE3 allelic frequency was 86%, ApoE2 and ApoE4 were 5 and 9%, respectively. We found no clear-cut association between apoE genotype and serum TG concentration. Macrosomia and LGA newborns were more frequent in IGT than in GDM or NGT (P < 0.01). In the 83 women with positive diabetic screening but normal glucose tolerance who delivered at term, the incidence of LGA infants was significantly higher in those with TG levels higher than the 75th percentile (> 2.30 mmol/l) (21%) than in mothers who had normal TG levels (4.5%) (P < 0.05). Pre-pregnancy BMI (r2 = 0.067), weight gain during pregnancy (r2 = 0.062), fasting serum TG (r2 = 0.09), and 2-h post-OGTT glucose levels (r2 = 0.044) were all associated with neonatal body weight (allP < 0.05 or less). However, on a multiple regression analysis, only pre-pregnancy BMI (F-test = 7.26,P < 0.01), and fasting serum TG (F-test = 4.07,P < 0.01) were independently associated with birth weight.Pre-pregnancy BMI and fasting maternal serum TG determined in the last trimester of gestation were independently associated with neonatal birth weight in women with normal glucose tolerance, but positive screening test. TG levels measured in the third trimester of pregnancy are independent of the genetic polymorphism of ApoE.Diabet. Med. (2004) [ABSTRACT FROM AUTHOR]

We report on the development of a highly directional, narrow energy band, short time duration proton beam operating at high repetition rate. The protons are generated with an ultrashort-pulse laser interacting with a solid target and converted to a pencil-like narrow-band beam using a compact magnet-based energy selector. We experimentally demonstrate the production of a proton beam with an energy of 500 keV and energy spread well below 10 % , and a pulse duration of 260 ps. The energy loss of this beam is measured in a 2 μ m thick solid Mylar target and found to be in good agreement with the theoretical predictions. The short time duration of the proton pulse makes it particularly well suited for applications involving the probing of highly transient plasma states produced in laser-matter interaction experiments. This proton source is particularly relevant for measurements of the proton stopping power in high energy density plasmas and warm dense matter. [ABSTRACT FROM AUTHOR]

The article explores the integrated quantitative particle-induced x-ray emission (PIXE) and energy dispersive x-ray (EDX) spectroscopy using a laser-driven particle source. It mentions that PIXE and EDX spectroscopy has been widely used in different scientific and technological fields. It discusses that development of a compact and multifunctional apparatus for the elemental analysis of materials based on a laser-driven particle source.

Fusion energy research is delivering impressive new results emerging from different infrastructures and industrial devices evolving rapidly from ideas to proof-of-principle demonstration and aiming at the conceptual design of reactors for the production of electricity. A major milestone has recently been announced in laser fusion by the Lawrence Livermore National Laboratory and is giving new thrust to laser-fusion energy research worldwide. Here we discuss how these circumstances strongly suggest the need for a European intermediate-energy facility dedicated to the physics and technology of laser-fusion ignition, the physics of fusion materials and advanced technologies for high-repetition-rate, high-average-power broadband lasers. We believe that the participation of the broader scientific community and the increased engagement of industry, in partnership with research and academic institutions, make most timely the construction of this infrastructure of extreme scientific attractiveness. [ABSTRACT FROM AUTHOR]

X-ray phase contrast imaging (XPCI) is more sensitive to density variations than X-ray absorption radiography, which is a crucial advantage when imaging weakly-absorbing, low-Z materials, or steep density gradients in matter under extreme conditions. Here, we describe the application of a polychromatic X-ray laser-plasma source (duration ~0.5 ps, photon energy >1 keV) to the study of a laser-driven shock travelling in plastic material. The XPCI technique allows for a clear identification of the shock front as well as of small-scale features present during the interaction. Quantitative analysis of the compressed object is achieved using a density map reconstructed from the experimental data. [ABSTRACT FROM AUTHOR]

A prototype of a highly adjustable Kirkpatrick-Baez (KB) microscope has been designed, built, and tested in a number of laser driven x-ray experiments using the high power (200 TW) VEGA-2 laser system of the Spanish Centre for Pulsed Lasers (CLPU). The presented KB version consists of two, perpendicularly mounted, 500 μm thick silicon wafers, coated with a layer of platinum, a few tens of nanometers thick. Unlike the usual millimeter thick glass substrate, this design allows for a larger bending flexibility and large adjustment range. According to simulations, this KB microscope offers broadband multikiloelectron volt reflection spectra (1 eV–20 keV), allowing more spectral tunability than conventional Bragg crystals. In addition to be vacuum compatible, this prototype is characterized by a relatively small size (21 cm × 31 cm × 27 cm) and permits remote control and modification both of the radii of curvature (down to 10 m) and of the grazing incidence angle (up to 60 mrad). A few examples of focusing performance tests and experimental results are discussed. [ABSTRACT FROM AUTHOR]

Micro-Raman spectroscopic technique allowed the characterization of organic and inorganic pigments of different colours sampled from a rock-art shelter named Abrigo del Aguila , located in the district of Badajoz, Cabeza del Buey (Extremadura – Spain). Micro-Raman analyses has been coupled with SEM observation and elemental analyses (EDS). The white and the black colours, used for non-representative figures, have been identified respectively as anatase and amorphous carbon, while two different type of red pigment has been found on figurative representations. The darker one, sampled, from a sun-figure, comprises an indeterminate organic compound beside of hematite. The second one, sampled from an anthropomorphic figure, is of a brilliant red and only hematite has been recognized in it. [ABSTRACT FROM AUTHOR]

The reliability of Fricke gel dosimeters in form of layers for measurements aimed at the characterization of epithermal neutron beams has been studied. By means of dosimeters of different isotopic composition (standard, containing 10 B or prepared with heavy water) placed against the collimator exit, the spatial distribution of gamma and fast neutron doses and of thermal neutron fluence are attained. In order to investigate the accuracy of the results obtained with in-air measurements, suitable MC simulations have been developed and experimental measurements have been performed utilizing Fricke gel dosimeters, thermoluminescence detectors and activation foils. The studies were related to the epithermal beam designed for BNCT irradiations at the research reactor LVR-15 (Řež). The results of calculation and measurements have revealed good consistency of gamma dose and fast neutron 2D distributions obtained with gel dosimeters in form of layers. In contrast, noticeable modification of thermal neutron fluence is caused by the neutron moderation produced by the dosimeter material. Fricke gel dosimeters in thin cylinders, with diameter not greater than 3 mm, have proved to give good results for thermal neutron profiling. For greater accuracy of all results, a better knowledge of the dependence of gel dosimeter sensitivity on radiation LET is needed. [ABSTRACT FROM AUTHOR]

Fricke–xylenol–orange gel has shown noticeable potentiality for in-phantom dosimetry in epithermal or thermal neutron fields with very high fluence rate, as those characteristic of nuclear research reactors. Fricke gels in form of layers give the possibility of achieving spatial distribution of gamma dose, fast neutron dose and dose due to charged particles generated by thermal neutron reactions. The thermal neutron fluence has been deduced from the dose coming from the charge particles emitted by neutron reactions with the isotope 10 B. Some measurements have been performed for improving the information on the relative sensitivity of Fricke gel dosimeters to the particles produced by 10 B reactions, because at present the precision of dose evaluations is limited by the scanty knowledge about the dependence of the dosimeter sensitivity on the radiation LET. For in-air measurements, the dosimeter material can produce an enhancement of thermal neutron fluence. Measurements and Monte Carlo calculations have been developed to investigate the importance of this effect. [ABSTRACT FROM AUTHOR]

In an experiment at the laser facility ECLIPSE of the CELIA laboratory, University of Bordeaux, we measure the reflectivity of spherically bent crystals that are commonly used to investigate the propagation of fast electrons through the Kα radiation they generate in matter. The experimental reflectivity compares well with predictions from a ray-tracing code that takes into account the specific geometry, although the crystals seem to suffer from aging problems. [ABSTRACT FROM AUTHOR]

This paper explores the processes involved in the production of prehistoric paintings using inorganic pigmentation. The focus for discussion involves a number of rock-shelter sites that contain rock art within the western part of the Iberian Peninsula, with particular reference to the sites that contain Schematic rock art. A direct date cannot be obtained on rock art that is made with inorganic pigments. However, sampling and subsequent analysis has clearly shown that pigments were produced using tried and tested recipes that involved the use of sometimes organic binders. This paper will explore the chemical and mineralogical qualities of sampled pigments from a selected number of sites within Spain and Portugal and suggest that pigmentation was more than just applying paint to rock. [ABSTRACT FROM AUTHOR]

We describe an experiment performed at the LULI laser facility using an advanced radiographic technique that allowed obtaining 2D, spatially resolved images of a shocked buried-code-target. The technique is suitable for applications on Fast Ignition as well as Warm Dense Matter research. In our experiment, it allowed to show cone survival up to Mbar pressures and to measure the shock front velocity and the fluid velocity associated to the laser-generated shock. This allowed obtaining one point on the shock polar of porous carbon. [ABSTRACT FROM AUTHOR]

The source conditions of volcanic plumes and collapsing fountains are investigated by means of large-scale experiments. In the experiments, gas-particle jets issuing from a cylindrical conduit are forced into the atmosphere at different mass flow rates. Dense jets (high particle volumetric concentration, e.g., C > 0.01) generate collapsing fountains, whose height scales with the squared exit velocity. This is consistent with Bernoulli's equation, which is a good approximation if air entrainment is negligible. In this case, kinetic energy is transformed into potential energy without any significant loss by friction with the atmosphere. The dense collapsing fountain, on hitting the ground, generates an intense shear flow similar to a pyroclastic density current. Dilute hot jets (low particle volumetric concentration, e.g., C < 0.01) dissipate their initial kinetic energy at much smaller heights than those predicted by Bernoulli's equation. This is an indication that part of the total mechanical energy is lost by friction with the atmosphere. Significant air entrainment results in this case, leading to the formation of a buoyant column (plume) from which particles settle similarly to pyroclastic fallout. The direct measurement of entrainment coefficient in the experiments suggests that dense collapsing fountains form only when air entrainment is not significant. This is a consequence of the large density difference between the jet and the atmosphere. Cold dilute experiments result in an entrainment coefficient of about 0.06, which is typical of pure jets of fluid dynamics. Hot dilute experiments result in an entrainment coefficient of about 0.11, which is typical of thermally buoyant plumes. The entrainment coefficients obtained by experiments were used as input data in numerical simulations of fountains and plumes. A numerical model was used to solve the classic top-hat system of governing equations, which averages the field variables (e.g., column velocity and density) across the column. The maximum heights calculated with the model agree well with those observed experimentally, showing that our entrainment coefficients are compatible with a top-hat model. Dimensional analysis of the experimental data shows that a value of 3 for the source densimetric Froude number characterizes the transition between dense collapsing fountains and dilute plumes. This value delimits the source conditions (exit velocity, conduit radius, and particle volumetric concentration) for pyroclastic flow (<3) and fallout (>3). [ABSTRACT FROM AUTHOR]

Abstract: Extensions of the standard stopping model (SSM) for ion projectiles interacting with dense targets of timely concern for ICF and WDM are reviewed. They include multiple scattering on partially degenerate electrons, low velocity ion slowing down in demixing H–He mixtures within Jovian planets core or multiionic target such as Kapton. [Copyright &y& Elsevier]

Pyroclastic density currents (PDCs) generated during the Plinian eruption of the Pomici di Avellino (PdA) of Somma–Vesuvius were investigated through field and laboratory studies, which allowed the detailed reconstruction of their eruptive and transportation dynamics and the calculation of key physical parameters of the currents. PDCs were generated during all the three phases that characterised the eruption, with eruptive dynamics driven by both magmatic and phreatomagmatic fragmentation. Flows generated during phases 1 and 2 (EU1 and EU3pf, magmatic fragmentation) have small dispersal areas and affected only part of the volcano slopes. Lithofacies analysis demonstrates that the flow-boundary zones were dominated by granular-flow regimes, which sometimes show transitions to traction regimes. PDCs generated during eruptive phase 3 (EU5, phreatomagmatic fragmentation) were the most voluminous and widespread in the whole of Somma–Vesuvius’ eruptive history, and affected a wide area around the volcano with deposit thicknesses of a few centimetres up to more than 25 km from source. Lithofacies analysis shows that the flow-boundary zones of EU5 PDCs were dominated by granular flows and traction regimes. Deposits of EU5 PDC show strong lithofacies variation northwards, from proximally thick, massive to stratified beds towards dominantly alternating beds of coarse and fine ash in distal reaches. The EU5 lithofacies also show strong lateral variability in proximal areas, passing from the western and northern to the eastern and southern volcano slopes, where the deposits are stacked beds of massive, accretionary lapilli-bearing fine ash. The sedimentological model developed for the PDCs of the PdA eruption explains these strong lithofacies variations in the light of the volcano’s morphology at the time of the eruption. In particular, the EU5 PDCs survived to pass over the break in slope between the volcano sides and the surrounding volcaniclastic apron–alluvial plain, with development of new flows from the previously suspended load. Pulses were developed within individual currents, leading to stepwise deposition on both the volcano slopes and the surrounding volcaniclastic apron and alluvial plain. Physical parameters including velocity, density and concentration profile with height were calculated for a flow of the phreatomagmatic phase of the eruption by applying a sedimentological method, and the values of the dynamic pressure were derived. Some hazard considerations are summarised on the assumption that, although not very probable, similar PDCs could develop during future eruptions of Somma–Vesuvius. [ABSTRACT FROM AUTHOR]

Abstract: A Free-Electron Laser (FEL) operating in the quantum regime can provide a compact and monochromatic X-ray source. Here we review the basic principles of a high-gain quantum FEL starting from noise, with special emphasis on the self-amplified spontaneous emission (SASE) mode operation. In the first part, the full quantum theory of the N-particle and single-radiation-mode FEL Hamiltonian is presented. Quantum effects such as cooperative gain, discrete spectrum and line narrowing are described, both in the multi-particle and in the second quantization formalism. In the second part, propagation effects (i.e. slippage) are described and the main features of the quantum SASE regime are discussed. The broad and spiky radiation spectrum observed in the classical SASE reduces in the quantum regime to a series of narrow lines, associated to sequential transitions between adjacent momentum states. A simple interpretation of the discrete nature of the spectrum and of the line width of the single spike observed in the quantum regime is presented. [Copyright &y& Elsevier]

Abstract: A compact tunable source of soft X-rays could be realized combining a state-of-the-art electron source with an intense counter-propagating laser pulse. If the source is operated in the quantum regime, the theoretical model predicts high monochromaticity (single-spike) and unprecedented temporal coherence for the emitted radiation. Here we present numerical simulations of the complete quantum model for an Free Electron Laser (FEL) with a laser wiggler in three spatial dimensions, based on a discrete Wigner function formalism taking into account the longitudinal momentum quantization. The numerical model includes the complete spatial and temporal evolution of the electron and radiation beams, with an explicit description of diffraction, propagation, laser wiggler profile and emittance effects. The contribution of each interaction term is studied independently, and the 3D results are contrasted with the 1D quantum FEL model neglecting transverse effects. Finally the parameter space for possible experiments is characterized, and a particular experimental case is discussed in detail. [Copyright &y& Elsevier]

Abstract: To assess whether HbA1c and plasma glucose predicts abnormal fetal growth, 758 pregnant women attending 5 Diabetic Centers were screened for gestational diabetes mellitus (GDM). On glucose challenge (GCT) at 24–27 weeks of gestation (g.w.), negative cases formed the normal control group (N1). Positive cases took an oral glucose tolerance test (OGTT): those found negative were classed as false positives screening test (N2); if they had an OGTT result at least as high as their normal glucose levels, they were classed as having one abnormal glucose value (OAV) at OGTT; two values as GDM. HbA1c was assayed on the day of GCT. We considered fetal macrosomia, large for gestational age (LGA), ponderal index and mean growth percentile. Mean age, pre-pregnancy BMI, fasting plasma glucose (FPG) and HbA1c were progressively higher from N1 to GDM patients. The newborn of N2 mothers were heavier than those with N1 or GDM. The mean growth percentile was significantly higher in N2 than in N1. More LGA babies were born to OAV than to N1 or N2 women. Macrosomia and ponderal index did not differ significantly in the four groups. At logistic regression only plasma glucose at GCT could predict LGA babies and a ponderal index above 2.85. At risk analysis, GDM and OAV significantly predicted LGA babies, and GDM a ponderal index >2.85. In conclusion, FPG at GCT could predict fetal overgrowth and plasma glucose >85mg/dl doubles the risk of LGA infants. HbA1c at 24–27g.w. does not predict fetal overgrowth. Mild alterations in glucose tolerance correlate with fetal overgrowth and needs monitoring and treatment. [Copyright &y& Elsevier]

Abstract: In this paper we specify the experimental parameters required to operate a Free Electron Laser with a laser wiggler in the Angstrom region. Both the quantum and the classical regimes are discussed. The quantum regime of SASE can be reached with more realistic parameters than the classical one. The fundamental feature of the quantum SASE is the extremely narrow single-line radiation spectrum, whose line width can be four orders of magnitude smaller than the bandwidth of the classical spiky SASE spectrum. [Copyright &y& Elsevier]

OBJECTIVE: The aim of this article was to define the metabolic phenotype of pregnant women with one abnormal value (OAV) during an oral glucose tolerance test (OGTT) and to test whether OAV could be considered metabolically comparable to gestational diabetes mellitus (GDM) or a specific entity between GDM and normal pregnancy. RESEARCH DESIGN AND METHODS: After 100-g 3-h OGTTs, 4,053 pregnant women were classified as having GDM, OAV, or normal glucose tolerance (NGT). Those with OAV were subdivided into three subgroups: fasting hyperglycemia (one abnormal value at fasting during an OGTT), 1-h hyperglycemia (one abnormal value at 1 h during an OGTT [1h-OAV]), or 2- or 3-h hyperglycemia (one abnormal value at 2 or 3 h during an OGTT). As derived from the OGTT, we measured insulin sensitivity (insulin sensitivity index [ISI] Matsuda) and insulin secretion (homeostasis model assessment for the estimation of beta-cell secretion [HOMA-B], first- and second-phase insulin secretion). The product of the first-phase index and the ISI was calculated to obtain the insulin secretion-sensitivity index (ISSI). RESULTS: GDM was diagnosed in 17.9% and OAV in 18.7% of pregnant women; women with GDM and OAV were older and had higher BMI and serum triglyceride levels than those with NGT (all P < 0.05). Women with NGT had the highest ISI followed by those with OAV (-21.7%) and GDM (-32.1%). HOMA-B results were comparable with those for OAV and GDM but significantly (P < 0.01) lower than those for NGT; first- and second-phase insulin secretion appeared progressively reduced from that in women with NGT to that in women with OAV and GDM (P < 0.01). ISSI was higher in women with NGT than in women with either OAV (-34%) or GDM (-51.7%) (P < 0.001). Among OAV subgroups, the 1h-OAV subgroup showed the lowest ISSI (P < 0.05). CONCLUSIONS: OAV and GDM are clinically indistinguishable, and both groups are different from women with NGT. Women with GDM and OAV showed impaired insulin secretion and insulin sensitivity, although these defects are more pronounced in women with GDM. Compared with other OAV subgroups, 1h-OAV could be considered a more severe condition. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses a study on gestational diabetes among pregnant Caucasian women.

Objectives: The aim of the present study was to evaluate the prevalence of alexithymia and its relationships with psychopathological features and suicide risk in a sample of adult patients with a DSM-IV diagnosis of paranoid schizophrenia. Method: A mixed male-female sample of 60 subjects (30 males and 30 females) was evaluetd with the following rating scales: Toronto Alexithymia Scale (TAS-20), Scale for the Assessment of Negative Symptoms (SANS), Scale for the Assessment of Positive Symptoms (SAPS), Calgary Depression Scale for Schizophrenia (CDSS), Scale for Suicidal Ideation (SSI), State-Trait Anxiety Inventory (STAI). RESULTS. 22 subjects (36.7%) were categorized as alexithymic (TAS-20 scores ≥ 61). Alexithymics showed more severe negative and depressive symptoms and increased suicide risk than nonalexithymics. However, the results of a linear regression with SSI score as dependent variable showed that Difficulty in Identifying and Describing Feelings dimensions of TAS-20 and higher CDSS scores were significantly associated with higher scores on the Scale for Suicide Ideation. Conclusions: The presence of alexithymia in schizophrenia may be related to higher risk of suicide ideation and more severe depressive symptoms, independently by the severity of positive and negative symptoms. However, results are preliminary and limitations must be considered. [ABSTRACT FROM AUTHOR]