We describe the development and demonstration of a high-repetition-rate-capable dual-channel (DC) x-ray spectrometer designed for high-intensity laser-plasma experiments (≥1×1021 W/cm2). The spectrometer, which operates at high repetition rates, is limited only by the refresh rate of targets and the camera's frame rate. It features two channels, each equipped with a flat highly oriented pyrolytic graphite (HOPG) crystal and a unique detector plane, allowing it to resolve two distinct x-ray bands: approximately 7-10 and 10-13 keV.
View Article and Find Full Text PDFWe present the development of a flexible tape-drive target system to generate and control secondary high-intensity laser-plasma sources. Its adjustable design permits the generation of relativistic MeV particles and x rays at high-intensity (i.e.
View Article and Find Full Text PDFThe importance of psychological well-being (PWB) is widely acknowledged in global policy and has important ramifications for health, performance, and engagement among sport performers. Despite this compelling knowledge, little is known about PWB in close sport relationships. We aimed to explore the interpersonal antecedents, transfer mechanisms, and outcomes of PWB within and among athletes, coaches, and sport psychology practitioners (SPPs).
View Article and Find Full Text PDFThe PROBIES diagnostic is a new, highly flexible, imaging and energy spectrometer designed for laser-accelerated protons. The diagnostic can detect low-mode spatial variations in the proton beam profile while resolving multiple energies on a single detector or more. When a radiochromic film stack is employed for "single-shot mode," the energy resolution of the stack can be greatly increased while reducing the need for large numbers of films; for example, a recently deployed version allowed for 180 unique energy measurements spanning ∼3 to 75 MeV with <0.
View Article and Find Full Text PDFA novel dual-energy fast neutron imaging technique is presented using short-pulse laser-driven neutron sources to leverage their inherent adaptive spectral control to enable 3D volume segmentation and reconstruction. Laser-accelerated ion beams incident onto secondary targets create directional, broadband, MeV-class neutrons. Synthetic radiographs are produced of multi-material objects using ion and neutron spectra derived from analytic and numerical models.
View Article and Find Full Text PDFA plasma mirror platform was developed for the OMEGA-EP facility to redirect beams, thus enabling more flexible experimental configurations as well as a platform that can be used in the future to improve laser contrast. The plasma mirror reflected a short pulse focusing beam at 22.5° angle of incidence onto a 12.
View Article and Find Full Text PDFWe present a deep learning based framework for real-time analysis of a differential filter based x-ray spectrometer that is common on short-pulse laser experiments. The analysis framework was trained with a large repository of synthetic data to retrieve key experimental metrics, such as slope temperature. With traditional analysis methods, these quantities would have to be extracted from data using a time-intensive and manual analysis.
View Article and Find Full Text PDFX-ray and neutrons are commonly used to image inertial confinement fusion implosions, providing key diagnostic information on the fuel assembly of burning deuterium-tritium (DT) fuel. The x-ray and neutron data provided are complementary as the production of neutrons and x-rays occurs from different physical processes, but typically these two images are collected from different views with no opportunity for co-registration of the two images. Neutrons are produced where the DT fusion fuel is burning; X-rays are produced in regions corresponding to high temperatures.
View Article and Find Full Text PDFA Chan-Lam reaction has been used to prepare N-alkenyl-α,β-unsaturated nitrones, which undergo a subsequent thermal rearrangement to the corresponding tri- and tetrasubstituted pyridines. The optimization and scope of these transformations is discussed. Initial mechanistic experiments suggest a reaction pathway involving oxygen transfer followed by cyclization.
View Article and Find Full Text PDFNeutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments.
View Article and Find Full Text PDFThe atmosphere and ionosphere of Venus have been studied in the past by spacecraft with remote sensing or in situ techniques. These early missions, however, have left us with questions about, for example, the atmospheric structure in the transition region from the upper troposphere to the lower mesosphere (50-90 km) and the remarkably variable structure of the ionosphere. Observations become increasingly difficult within and below the global cloud deck (<50 km altitude), where strong absorption greatly limits the available investigative spectrum to a few infrared windows and the radio range.
View Article and Find Full Text PDFAlthough 2-dimensional echocardiography with adjunct intravenous contrast media improves endocardial visualization and enhances quality of spectral Doppler signals, widespread use of contrast agents has not occurred for various reasons. Results from this study indicate that discretionary use of contrast media will enhance endocardial and Doppler signal visualization scores without an impact on total procedure duration, lending credence to an argument for a lower threshold for discretionary use of contrast media.
View Article and Find Full Text PDFDelayed splenic rupture, though uncommon, is a recognised clinical condition and is associated with a significant mortality rate. In the vast majority of cases the patient re-presents with abdominal symptoms and/or signs of acute intraperitoneal haemorrhage. A case is presented of delayed splenic rupture presenting with jaundice attributable to intra-abdominal clot lysis.
View Article and Find Full Text PDFBackground: The aim was to assess the role of plasma Big Endothelin (ET) 1 levels as a marker of disease presence and stage in colorectal adenocarcinoma.
Methods: Big ET-1 was measured in the plasma of 37 patients with colorectal cancer. Preoperative systemic plasma levels of Big ET-1 in patients with cancer were compared with levels in 20 age- and sex-matched controls.
Infect Control Hosp Epidemiol
October 1998
Objectives: To establish the concentration of isopropanol that exerts the same immediate and sustained effects as n-propanol 60% v/v in surgical scrubbing, and to assess the performance of the test method proposed as the European standard in parallel experiments.
Design: Isopropanol at concentrations of 70%, 80%, and 90% v/v was tested in comparison with n-propanol 60%, the proposed reference preparation, in the draft method proposed by the European standard. A Latin square design was used with four balanced blocks of five volunteers each in four experimental runs that were spaced by intervals of 1 week each.
A bistatic radar experiment in 1994, involving reception on Earth of a specularly reflected, linearly polarized 13-centimeter-wavelength signal transmitted from the Magellan spacecraft in orbit around Venus, has established that the surface materials viewed at low and intermediate altitudes on Venus have a relative dielectric permittivity of 4.0 ± 0.5.
View Article and Find Full Text PDFEpidemiol Infect
December 1995
The efficacy of sodium hypochlorite was assessed against human immunodeficiency virus type 1 suspended in low (8% v/v) or high (80% v/v) concentrations of serum or in a high (80%) concentration of blood. In the presence of 8% serum, 100 p.p.
View Article and Find Full Text PDFIn the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon.
View Article and Find Full Text PDFA common assertion in the literature is that Langhans cells in placental villi decline in number during gestation but this is a misinterpretation which may be caused by the greater growth of villous surface area compared with trophoblast volume. To test this possibility, human placentae were collected at 12-41 weeks of gestation for a cross-sectional study on the packing density of nuclei within villous trophoblast. Numbers of nuclei in the cyto- and syncytiotrophoblast were estimated using a design-based stereological device, the physical disector (parallel pairs of sections).
View Article and Find Full Text PDFAlcohols are commonly used as disinfectants for skin, surfaces and immersion of some medical instruments. Measurements of the activity of alcohols against human immunodeficiency virus type 1 (HIV-1) must take account of the compatibility of neutralizers used to stop the disinfectant reaction, and of toxicity to the cell line used to detect residual virus. We have developed protocols to measure the efficacy of alcohols against HIV in suspension and dried onto surfaces in the presence of high and low protein concentrations.
View Article and Find Full Text PDFA cross-sectional sample of human placentae was collected at 12-41 wk, and growth mechanisms within villous subcompartments (trophoblast epithelium, stroma and fetal capillary endothelium) were assessed using state-of-the-art design-based stereological methods. Physical disectors (adjacent pairs of sections) were used to count nuclei in syncytiotrophoblast and in cells of the cytotrophoblast, stroma and endothelium. The volumes of trophoblast and stroma and the surface areas and lengths of capillaries were employed to assess the overall growth of each compartment.
View Article and Find Full Text PDFProcedures used for cleaning/disinfection of fibreoptic bronchoscopes and incidents of mycobacterial contamination were assessed by postal questionnaire. Information supplied by the Infection Control Doctor in 129 of 198 hospitals (65.2%) was used to audit local practice for compliance with national guidelines.
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