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The effects of large-scale (with Legendre modes ≲10) asymmetries in OMEGA direct-drive implosions caused by laser illumination nonuniformities (beam-power imbalance and beam mispointing and mistiming), target offset, and variation in target-layer thickness were investigated using the low-noise, three-dimensional Eulerian hydrodynamic code ASTER. Simulations indicate that these asymmetries can significantly degrade the implosion performance. The most important sources of the asymmetries are the target offsets ( ∼10 to 20 μm), beam-power imbalance ( σrms∼10%), and variations ( ∼5%) in target-layer thickness. Large-scale asymmetries distort implosion cores, resulting in a reduced hot-spot confinement and an increased residual kinetic energy of implosion targets. The ion temperature inferred from the width of simulated neutron spectra is influenced by bulk fuel motion in the distorted hot spot and can result in up to an ∼1-keV increase in apparent temperature. Similar temperature variations along different li...

Sb 0.2 Bi 1.8 Te 3 single crystals have been grown by the zone melting and Bridgman–Stockbarger methods. The freezing interface temperature gradients of 90°C/cm and 45°C/cm, respectively, have been found to yield the best quality crytals obtainable at the growth rate of 0.35 cm/h. The crystals have been characterized by the powder XRD technique. The crystals grown by the zone melting method have been observed to exhibit certain typical features on their top free surfaces. A new dislocation etchant has been developed to give reproducible etch-pitting on the cleavage surface. Tests of this dislocation etchant have been carried out successfully and the etchant has been used to obtain dislocation density in the crystals.

InBi 0.8 Sb 0.2 single crystals have been grown by zone melting method. The freezing interface temperature gradient of 30°C/cm has been found to yield the best quality crystals obtainable at growth velocity 1.0 cm/hr. Triangular features have been obtained on the free surface of the as grown crystal. A new dislocation etchant based on nitric acid has been found to give reproducible etch-pitting on the cleavage surface. Standard tests for a dislocation etchant have been carried out and results are reported.

Here we present experimental results on laser-driven ion accel- eration from relativistically transparent, overdense plasmas in the break-out afterburner (BOA) regime. Experiments were preformed at the Trident ultra-high contrast laser facility at Los Alamos National Laboratory, and at the Texas Petawatt laser facility, located in the University of Texas at Austin. It is shown that when the target becomes relativistically transparent to the laser, an epoch of dramatic acceleration of ions occurs that lasts until the electron density in the expanding target reduces to the critical density in the non-relativistic limit. For given laser parameters, the optimal target thickness yielding the highest maximum ion energy is one in which this time window for ion acceleration overlaps with the intensity peak of the laser pulse. A simple analytic model of relativistically induced transparency is presented for plasma expansion at the

Experimental data are presented for laser-driven carbon C6+ ion-acceleration, verifying 2D-PIC studies for multi-species targets in the Break-Out Afterburner regime. With Trident's ultra-high contrast at relativistic intensities of 5 × 1020 W/cm2 and nm-scale diamond targets, acceleration of carbon ions has been optimized by using target laser-preheating for removal of surface proton contaminants. Using a high-resolution wide angle spectrometer, carbon C6+ ion energies exceeding 1 GeV or 83 MeV/amu have been measured, which is a 40% increase in maximum ion energy over uncleaned targets. These results are consistent with kinetic plasma modeling and analytic theory.

We present experimental data and PIC simulations on laser driven ion acceleration in the relativistic transparent regime. We measured carbon C6+ ions energies exceeding 1GeV and proton energies exceeding 100MeV. Conversion efficiency of laser light into ions, beam shape and scaling laws are presented for this regime and compared to the Target Normal Sheath acceleration and Radiation pressure acceleration regime.

Fourth-order cross-correlation of the laser pulse is obtained from the spectral interferogram produced from the laser pulse and a self-created reference pulse. High dynamic range contrast measurement (60 dB) is demonstrated by measuring an imposed pre-pulse.

A Particle X-ray Temporal Diagnostic (PXTD) has been implemented on OMEGA for simultaneous time-resolved measurements of several nuclear products as well as the x-ray continuum produced in High Energy Density Plasmas and Inertial Confinement Fusion implosions. The PXTD removes systematic timing uncertainties typically introduced by using multiple instruments, and it has been used to measure DD, DT, D3He, and T3He reaction histories and the emission history of the x-ray core continuum with relative timing uncertainties within ±10-20 ps. This enables, for the first time, accurate and simultaneous measurements of the x-ray emission histories, nuclear reaction histories, their time differences, and measurements of Ti(t) and Te(t) from which an assessment of multiple-ion-fluid effects, kinetic effects during the shock-burn phase, and ion-electron equilibration rates can be made.

We present results from the comparison of high-resolution three-dimensional (3D) simulations with data from the implosions of inertial confinement fusion capsules with separated reactants performed on the OMEGA laser facility. Each capsule, referred to as a “CD Mixcap,” is filled with tritium and has a polystyrene (CH) shell with a deuterated polystyrene (CD) layer whose burial depth is varied. In these implosions, fusion reactions between deuterium and tritium ions can occur only in the presence of atomic mix between the gas fill and shell material. The simulations feature accurate models for all known experimental asymmetries and do not employ any adjustable parameters to improve agreement with experimental data. Simulations are performed with the RAGE radiation-hydrodynamics code using an Implicit Large Eddy Simulation (ILES) strategy for the hydrodynamics. We obtain good agreement with the experimental data, including the DT/TT neutron yield ratios used to diagnose mix, for all burial depths of the deuterated shell layer. Additionally, simulations demonstrate good agreement with converged simulations employing explicit models for plasma diffusion and viscosity, suggesting that the implicit sub-grid model used in ILES is sufficient to model these processes in these experiments. In our simulations, mixing is driven by short-wavelength asymmetries and longer-wavelength features are responsible for developing flows that transport mixed material towards the center of the hot spot. Mix material transported by this process is responsible for most of the mix (DT) yield even for the capsule with a CD layer adjacent to the tritium fuel. Consistent with our previous results, mix does not play a significant role in TT neutron yield degradation; instead, this is dominated by the displacement of fuel from the center of the implosion due to the development of turbulent instabilities seeded by long-wavelength asymmetries. Through these processes, the long-wavelength asymmetries degrade TT yield more than the DT yield and thus bring DT/TT neutron yield ratios into agreement with experiment. Finally, we present a detailed comparison of the flows in 2D and 3D simulations.

We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR~15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.

Capsules driven with polar drive [1, 2] on the National Ignition Facility [3] are being used [4] to study mix in convergent geometry. In preparation for experiments that will utilize deuterated plastic shells with a pure tritium fill, hydrogen-filled capsules with copper- doped deuterated layers have been imploded on NIF to provide spectroscopic and nuclear measurements of capsule performance. Experiments have shown that the mix region, when composed of shell material doped with about 1% copper (by atom), reaches temperatures of about 2 keV, while undoped mixed regions reach about 3 keV. Based on the yield from these implosions, we estimate the thickness of CD that mixed into the gas as between about 0.25 and 0.43 μm of the inner capsule surface, corresponding to about 5 to 9 μg of material. Using 5 atm of tritium as the fill gas should result in over 1013 DT neutrons being produced, which is sufficient for neutron imaging [5].

International audience; Bright femtosecond x-ray beams, with energies up to a few hundreds of keV, have been produced from Betatron oscillations and Compton scattering in a laser-plasma accelerator. The potential of Betatron radiation for phase contrast imaging has been demonstrated. (C) 2011 Optical Society of America

One of the major goals of research for laser-plasma accelerators is the realization of compact sources of femtosecond X-rays. In particular, using the modest electron energies obtained with existing laser systems, Compton scattering a photon beam off a relativistic electron bunch has been proposed as a source of high-energy and high-brightness photons. However, laser-plasma based approaches to Compton scattering have not, to date, produced X-rays above 1 keV. Here, we present a simple and compact scheme for a Compton source based on the combination of a laser-plasma accelerator and a plasma mirror. This approach is used to produce a broadband spectrum of X-rays extending up to hundreds of keV and with a 10,000-fold increase in brightness over Compton X-ray sources based on conventional accelerators. We anticipate that this technique will lead to compact, high-repetition-rate sources of ultrafast (femtosecond), tunable (X- through gamma-ray) and low-divergence (~1 degree) photons from source sizes on the order of a micrometre., 6 pages, 5 figures

Bright and high-energy femtosecond x-ray beams were produced from Betatron oscillations and Compton scattering in laser-plasma accelerators. Their use as a diagnostic for laser-plasma accelerators and for applications was demonstrated.

Non-linear pulse cleaning is used along with an OPA front end and improved stretcher designs to improve pre-pulse contrast on the high intensity short pulse beam line of the Trident Laser.

Bi–Sb single crystals (with Sb concentration varied up to 30 at. %) have been subjected to impact loading in the form of dynamic indentation on their (111) cleavage planes. The resulting mechanical twins are the theme of this report. The tensile and compressive stresses developed by the spherical indenter employed have been differentiated with respect to their role in producing the twins. While the twins produced in the crystals with Sb ≤15 at. % are interpreted as being due to tensile stresses, those in the crystals with Sb>15 at. % are found to be due to compressive stresses.

Relevant to laser based electron/ion accelerations, a single shot second harmonic generation frequency resolved optical gating (FROG) system has been developed to characterize laser pulses (80 J, ∼600 fs) incident on and transmitted through nanofoil targets, employing relay imaging, spatial filter, and partially coated glass substrates to reduce spatial nonuniformity and B-integral. The device can be completely aligned without using a pulsed laser source. Variations of incident pulse shape were measured from durations of 613 fs (nearly symmetric shape) to 571 fs (asymmetric shape with pre- or postpulse). The FROG measurements are consistent with independent spectral and autocorrelation measurements.

We demonstrate the use of low-gain optical parametric amplification (OPA) as a means of improving temporal contrast to a detection-limited level 10(-10). 250 microJ, 500 fs pulses of 1053 nm are frequency doubled and subsequently restored to the original wavelength by OPA with10% efficiency.

The acceleration of electrons from ultra-thin foils using high-intensity lasers has recently gained high interest due to the outstanding characteristics of the generated electron beam observed in particle-in-cell simulations. Here, the generation of a relativistic electron bunch of ultra-high density was demonstrated which may be well-suited for the generation of ultra-short coherent x-ray radiation via Thomson back-scattering2.

The high contrast front-end for the 200 TW Trident laser has shown in recent experiments the importance roles that Amplified Spontaneous Emission (ASE) and prepulse contrast play in laser-ion acceleration. Ion energies above 58 MeV with efficiencies of greater than 5% into ions above 4 MeV have been observed even at modest intensities, on par with the Nova Petawatt results2 at half the intensity1, and a fifth of the energy and power, at an intrinsic laser ASE contrast of ≫ 10−7. Scalings for, laser energy, intensity, and target thickness are presented and compared to other empirical scalings and theories, including results of the new ultra-high contrast ≫10−10 Optical Parametric Chirped-Pulse Amplification (OPCPA) front-end system3.

Laser-driven particle acceleration has been under intense investigation for the last decade and is of particular interest for key applications such as medical physics, fast ignition and inertial confinement fusion. The dominant ion acceleration mechanism is known as target normal sheath acceleration (TNSA); although easy accessible it suffers from a low energy conversion efficiency. Recently reported maximum ion energies1 are in the range of a few tens of MeV, which is well below the energies needed for most applications. Recently proposed acceleration mechanisms utilize ultra-high contrast laser pulses and ultra-thin solid targets allowing for generation of ions in the GeV range from intense laser-plasma interaction. A high laser contrast suppresses pre-ionization of the solid target by any pre-pulses or laser pedestals and in theory enables acceleration beyond TNSA in regimes such as the break-out afterburner (BOA)2 or radiation pressure acceleration (RPA).

An experimental investigation was conducted to study the interaction of combined modes of loading on crack instability in the presence of the opening and sliding modes of stress intensity factors, the opening and tearing modes of stress intensity factors, and all three modes of stress intensity factors. Through-cracked and surface-cracked flat and round specimens, and round notched bar specimens fabricated from high strength 4340 steel were used for the investigation. The results are evaluated to determine fracture criteria under the combined modes of stress intensity factors for the 4340 steel. These results are compared with the results of other investigators obtained for different materials.

International audience; Energetic electron beams accelerated in a laser-produced plasma wakefield cavity can generate collimated beams of X-ray radiation. The oscillation of the electrons in the plasma cavity produces synchrotron-like emission, called betatron radiation. On the basis of state of the art experiments, we discuss the potentiality of this source in terms of spectral brigthness and flux. These characteristics are compared to existing and planned X-ray sources in both laser and accelerator communities.

International audience; This Letter aims to demonstrate the ultrafast nature of laser produced betatron radiation and its potential for application experiments. An upper estimate of the betatron x-ray pulse duration has been obtained by performing a time-resolved x-ray diffraction experiment: The ultrafast nonthermal melting of a semiconductor crystal (InSb) has been used to trigger the betatron x-ray beam diffracted from the surface. An x-ray pulse duration of less than 1 ps at full width half-maximum (FWHM) has been measured with a best fit obtained for 100 fs FWHM.

Polar-direct-drive experiments conducted at the National Ignition Facility [E. I. Moses, Fusion Sci. Technol. 54, 361 (2008)] performed at laser irradiance between 1 and 2×1015 W/cm2 exhibit increased hard x-ray emission, decreased neutron yield, and reduced areal density as the irradiance is increased. Experimental x-ray images at the higher irradiances show x-ray emission at the equator, as well as degraded symmetry, that is not predicted in hydrodynamic simulations using flux-limited energy transport, but that appear when non-local electron transport together with a model to account for cross beam energy transfer (CBET) is utilized. The reduction in laser power for equatorial beams required in the simulations to reproduce the effects of CBET on the observed symmetry also reproduces the yield degradation consistent with experimental data.

We report recent results of experiments in which relativistic optical effects play an important role, at peak laser intensities above 1019 W/cm2. These effects are leading to novel radiation sources, all with femtosecond pulse durations: (1) the generation of optical photons by means of pulse compression via relativistic cross‐phase modulation, (2) ponderomotive deflection of laser accelerated electron beams, and (3) the generation of well‐collimated keV‐energy x‐ray beams by means of either Thomson scattering or betatron oscillations in ion channels.

Collimated beams of radiation can now be generated in the X‐ray spectral range using laser systems. These new tools may provide efficient probing radiation for the analysis of dense plasmas and ultrafast atomic dynamics phenomena in the matter. Using relativistic laser‐matter interaction, we have shown that X‐ray radiation can be emitted within a collimated 20 mrad cone, in the spectral range of few keV, and with the additional unique properties to be ultrafast (100 fs timescale) and perfectly synchronized with the driving laser system.

Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

Ion acceleration from relativistic laser solid interactions has been of particular interest over the last decade. While beam profiles have been studied for target normal sheath acceleration (TNSA), such profiles have yet to be described for other mechanisms. Here, experimental data is presented, investigating ion beam profiles from acceleration governed by relativistic transparent laser plasma interaction. The beam shape of carbon C6+ ions and protons has been measured simultaneously with a wide angle spectrometer. It was found that ion beams deviate from the typical Gaussian-like shape found with TNSA and that the profile is governed by electron dynamics in the volumetric laser?plasma interaction with a relativistically transparent plasma; due to the ponderomotive force electrons are depleted from the center of the laser axis and form lobes affecting the ion beam structure. The results are in good agreement with high resolution three-dimensional-VPIC simulations and can be used as a new tool to experimentally distinguish between different acceleration mechanisms.

To determine the age related prevalence of Varicella Zoster Virus (VZV) antibodies in India.This was a cross sectional multicentric study performed in 4 major cities of India: Calcutta (outpatients), Mumbai (outpatients), Lucknow (walk-in patients to a diagnostic laboratory, orphanage and factory workers) and Bangalore (outpatients and walk-in patients to a diagnostic laboratory).A total of 1609 volunteers from birth to 40 years of age were included into the study. IgG antibodies against VZV were determined using commercial kits (ELISA-Enzygnost).Overall seroprevalence of anti VZV antibodies was 68. 22percnt. The age related seroprevalence rate of anti VZV antibodies was 29percnt in the age group of 1-5 years, 51.1percnt in 5-10 years, 71.7percnt in 11-15 years, 79.8percnt in 16-20 years, 88.1percnt in 21-30 years and 91.1percnt in 31-40 years.A significant proportion of adolescents and adults are susceptible to varicella in India, as in other tropical countries

The Trident laser facility at Los Alamos National Laboratory (LANL) has served for more than 20 years as an important tool in inertial confinement fusion (ICF) and Material Dynamics research. An energy and power upgrade of the short-pulse beam line to 100J / 200 TW was made in 2007 and contrast improvements have been made continually since. The combination of this powerful new short-pulse beamline with the two flexible long pulse beamlines, and a total of three different target areas, makes Trident a highly flexible and versatile research tool for high energy density laboratory plasma (HEDLP) research. The newest “Dial-a-Contrast” (DaC) features are described, along with nominal performance of the laser at the presently available highest contrast.

There is a strong correlation between gingival inflammation and clinical and sub-clinical ascorbic acid deficiency. This has created a demand for a handy diagnostic test to detect the ascorbic acid deficiency. The aim of this work was to find out the efficacy of one such test, i.e. the modified Lingual Ascorbic Acid Test (LAAT). To find out the significance of ths LAAT, it was compared with plasma ascorbic acid levels and then confirmed statistically. Our findings suggest that with this simple, reliable and inexpensive method, the dental practitioners can conveniently assess the ascorbic acid status of their patients.

Research on fusion fast ignition (FI) initiated by laser-driven ion beams has made substantial progress in the last years. Compared with electrons, FI based on a beam of quasi-monoenergetic ions has the advantage of a more localized energy deposition, and stiffer particle transport, bringing the required total beam energy close to the theoretical minimum. Due to short pulse laser drive, the ion beam can easily deliver the 200 TW power required to ignite the compressed D–T fuel. In integrated calculations we recently simulated ion-based FI targets with high fusion gain targets and a proof of principle experiment [1]. These simulations identify three key requirements for the success of ion-driven fast ignition (IFI): (1) the generation of a sufficiently high-energetic ion beam (≈400–500 MeV for C), with (2) less than 20% energy spread at (3) more than 10% conversion efficiency of laser to beam energy. Here we present for the first time new experimental results, demonstrating all three parameters in separate experiments. Using diamond nanotargets and ultrahigh contrast laser pulses we were able to demonstrate >500 MeV carbon ions, as well as carbon pulses with ΔE/E < 20%. The first measurements put the total conversion efficiency of laser light into high energy carbon ions on the order of 10%.

CRA9015 Background: Hot flashes are a common symptom during the menopause transition or following breast cancer treatment that can negatively impact the quality of life for many women. Preliminary data have suggested that flaxseed, a rich source of dietary lignans, may be a potentially effective treatment for hot flashes. Methods: A phase III randomized, placebo controlled trial was conducted to evaluate the efficacy of flaxseed in reducing hot flashes. Postmenopausal women were randomly assigned to a flaxseed bar (providing 410 mg of lignans) for 6 weeks vs a placebo bar. Participants completed daily prospective, self report hot flash diaries during the baseline week and then began eating one study bar per day for 6 weeks, while continuing to record their daily hot flashes. The intra-patient difference in hot flash activity between baseline and the last treatment week was the primary endpoint. Side effects of the bars were evaluated through self report and CTC assessment. Results: Between October and December 2009, 188 women were enrolled onto this trial. Mean hot flash scores were reduced by 4.9 units in the flaxseed group and 3.5 in the placebo group (p=0.29). In both groups, a little over a third of the women received a 50% reduction in their hot flash scores. Only one side effect was significantly different between groups, that being grade 1 pruritis, which was more common (7%) in the placebo group versus 1% in the flaxseed group. Both groups reported increased abdominal distension, flatulence, diarrhea and nausea. Adherence and ability to detect treatment assignment did not differ between groups. Conclusions: The results of this trial do not support the use of 410 mg of flaxseed lignans for the reduction of hot flashes. The gastrointestinal side effects seen in both groups were likely due to the fiber content in the flaxseed and placebo bars.

Kinetic simulations of break-out-afterburner (BOA) ion acceleration from nm-scale targets are examined in a longer pulse length regime than studied previously. It is shown that when the target becomes relativistically transparent to the laser, an epoch of dramatic acceleration of ions occurs that lasts until the electron density in the expanding target reduces to the critical density in the non-relativistic limit. For given laser parameters, the optimal target thickness yielding the highest maximum ion energy is one in which this time window for ion acceleration overlaps with the intensity peak of the laser pulse. A simple analytic model of relativistically induced transparency is presented for plasma expansion at the time-evolving sound speed, from which these times may be estimated. The maximum ion energy attainable is controlled by the finite acceleration volume and time over which the BOA acts.

9027 Background: Hot flashes (HFs) occur in approximately 2/3 of androgen-deprived men. There is limited data on treatment from prospective intervention studies. Methods: Eligible androgen-deprived...

In recent experiments at the Trident laser facility, quasi-monoenergetic ion beams have been obtained from the interaction of an ultraintense, circularly polarized laser with a diamond-like carbon target of nm-scale thickness under conditions of ultrahigh laser pulse contrast. Kinetic simulations of this experiment under realistic laser and plasma conditions show that relativistic transparency occurs before significant radiation pressure acceleration and that the main ion acceleration occurs after the onset of relativistic transparency. Associated with this transition are a period of intense ion acceleration and the generation of a new class of ion solitons that naturally give rise to quasi-monoenergetic ion beams. An analytic theory has been derived for the properties of these solitons that reproduces the behavior observed in kinetic simulations and the experiments.

A novel ion wide angle spectrometer (iWASP) has been developed, which is capable of measuring angularly resolved energy distributions of protons and a second ion species, such as carbon C(6 +), simultaneously. The energy resolution for protons and carbon ions is better than 10% at ∼50 MeV/nucleon and thus suitable for the study of novel laser-ion acceleration schemes aiming for ultrahigh particle energies. A wedged magnet design enables an acceptance angle of 30°(∼524 mrad) and high angular accuracy in the μrad range. First, results obtained at the LANL Trident laser facility are presented demonstrating high energy and angular resolution of this novel iWASP.

Five hundred children below the age of 12 years suffering from lung tuberculosis viz., primary complex (PC) or progressive primary complex (PPC) were studied. Diagnosis was based on Kenneth Jones criteria; selected cases having score of 5 or more. One hundred and eighty cases of PC were given A-1 (6 RH) regimen, while 312 cases of PPC were given A-2 (2SHRZ/4 RH) or A-3 (2 SRH/4 RH) or A-4 (2 RHE/4 RH) regimen. Follow-up was done for 6 months after completing the treatment to observe the relapse rate. In cases of PC, 6 RH regimen appeared adequate and cheaper with no relapse rate. In cases of PPC with short course chemotherapy, compliance of patients had been very good. Relapse rate was up to 13% which is acceptable. Drug toxicity was very low.

International audience; This paper presents the complete characterization of a kilo-electron-volt laser-based x-ray source. The main parameters of the electron motion (amplitude of oscillations and initial energy) in the laser wakefield have been investigated using three independent methods relying on spectral and spatial properties of this betatron x-ray source. First we will show studies on the spectral correlation between electrons and x-rays that is analyzed using a numerical code to calculate the expected photon spectra from the experimentally measured electron spectra. High-resolution x-ray spectrometers have been used to characterize the x-ray spectra within 0.8–3 keV and to show that the betatron oscillations lie within 1 µm. Then we observed Fresnel edge diffraction of the x-ray beam. The observed diffraction at the center energy of 4 keV agrees with the Gaussian incoherent source profile of full width half maximum

Critical strain energy release rates GIc for interlaminar fracture were determined under pure mode I loading conditions for tougher thermoset material systems AS6/2220-3 and AS6/5245C. GIc values were determined with constant-width, double-cantilever beam specimens for room temperature (RT)/dry, RT/wet, and -75°F/dry conditions. The critical strain energy release rates GTc under mixed mode I-II loading conditions were also determined for these materials with cracked lap shear (CLS) specimens for RT/dry and RT/wet conditions. Both AS6/2220-3 and AS6/5245C material systems have significantly higher interlaminar fracture toughness compared to currently used composite systems such as T300/5208. Delamination growth rates dtf/d/V were also determined experimentally for the above material systems under pure mode I and mixed mode I-II loading conditions for the above-mentioned environmental conditions. Delamination growth rates were plotted and correlated with the maximum applied strain energy release rate G! or GT. Growth rate equations were determined for each material and environmental condition. Delamination growth rates were also compared with those of the T300/5208 system. da/d/Vfor AS6/5245C for RT/wet environment is significantly higher than that for RT/dry conditions. Striation markings were observed for CLS specimens. Delamination growth rates vs from striations correlated very well with those from visually observed crack length data.

The laser/flash photolysis-resonance fluorescence technique was employed to study the kinetics of the reaction OH + COS →k1 products. Complicating secondary reactions involving COS photofragments were eliminated by using 193 nm laser photolysis of HNO3 as a source of OH. The rate constant was found to be much slower than previous measurements indicated. Based on our experiments, the upper limit for k1 at 298K is 8.8 × 10−15 cm³molecule−1s−1. Our results suggest that the title reaction is only a minor COS degradation pathway in the troposphere.

Approximate stress intensity factors (SIF’s) are derived for through-the-thickness cracks originating at an interference fit fastener- (IFF-) filled hole in a uniaxially loaded plate. SIF’s are determined using a previously formulated procedure of deriving approximate SIF’s from the normal stress distribution at the location of the crack in an uncracked plate. An approximate elastic-plastic solution for the normal stress distribution is derived for a uniaxially loaded plate containing an IFF-filled hole. Stress distributions obtained from the approximate solution compare well with those obtained from elastic-plastic finite element analyses for various loading conditions, interference levels and fastener plate material combinations. SIF’s for through cracks at IFF’s are presented graphically for various ratios of crack length to hole radius and diametral interference to hole diameter, applied uniaxial stresses and the plate-fastener material combinations. Finally, these SIF’s are used to predict residual cyclic lives of test specimens containing through cracks at IFF’s. Agreement between the calculated and actual lives is very good.

SummaryThe net assimilation rates (NAR) of three genotypes of cotton differing in their growth habit were studied under different spacings. The NARs of a very bushy type, G 67, and a comparatively less spreading type, IAN 560, were the same but that of a compact type, IAN 579, was twice as much when the leaf area index (LAI) was one. Though subsequently in G 67 and IAN 560 NAR under varying spacings either decreased less rapidly or remained steady, the decrease was nearly Hnear with increasing LAI. However, for IAN 579 dependence of NAR on LAI was generally positive indicating genotypic improvement. Under different spacings the leaf-density dependance of NAR appeared to have been decreased in IAN 560, but was nearly absent in IAN 579 with more efficiency towards increasing the yield of seed cotton.

The flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the reaction OH + CS/sub 2/ ..-->.. products (k/sub 1/) over the temperature range 251-363 K. Complicating secondary reactions involving CS/sub 2/ photofragments were eliminated only when the photoflash was filtered by 10 torr cm of CS/sub 2/ and SF/sub 6/ was used as the buffer gas. The rate constant was found to be much slower than previous measurements indicated. Based on our experiments, upper limits for k/sub 1/ (in units of 10/sup -15/ cm/sup 3/ molecule/sup -1/s/sup -1/) are 9.9 at 251 K, 1.5 at 297 K, and 1.6 at 363 K. Our results suggest that the title reaction is unimportant as a source for COS in the atmosphere.

Chemical kinetics for the decomposition of vitamin A, vitamin B1, sodium pantothenate, folic acid and vitamin B12 were studied at higher temperatures in the case of two multi-vitamin preparations. Vitamin A, vitamin B1 and sodium pantothenate were found to decompose in accordance with the first order reaction at higher temperatures, whereas folic acid and vitamin B12 did not follow first order kinetics. It was concluded that, in the cases of multivitamin preparations, accelerated study at higher temperatures was feasible only in the case of vitamin A, vitamin B1 and sodium pantothenate.

Stress intensity magnification factors for an elliptical crack embedded in a finite thickness plate subjected to tensile and bending loading are estimated by judicious use of analytical results obtained previously. These analytical results involve the stress intensity magnification factors for an embedded elliptical crack approaching the free surface of a semi-infinite solid and pressurized by a constant or by a linearly varying pressure. The resultant stress intensity magnification factors for the elliptical crack in a plate are presented in graphical forms for various crack aspect ratios, eccentricity, and proximity factors.