Article on the role of hypoxia in the evolution and development of the cardiovascular system.

Article discussing the linear free energy relationship correlations for enthalpies of solvation of organic solutes into room-temperature ionic liquids based on the Abraham model with ion-specific equation coefficients.

The notion of formalized music implies that a musical composition can be described in mathematical terms. In this article we explore some formal aspects of music and propose a framework for an abstract approach.

Three basic core material types for sandwich structure applications are studied. The three two-dimensional pattern types are: honeycomb, triangular cells, and a new configuration involving star type cells. The specific critical properties of stiffness and strength type are identified and studied, both theoretically and experimentally.

Experiments are being developed to shock compress metal foils in the solid state to study the material strength under high compression. The x-ray drive has been characterized and hydrodynamics experiments performed to study growth of the Rayleigh-Taylor (RT) instability in Al foils at a peak pressure of about 1.8 Mbar. Pre-imposed modulations with an initial wavelength of lo-50 pm, and amplitude of 0.5 pm show growth. Variation in the growth factors may be a result of shot-shot variation in preheating of the Al sample due to emission from the plasma in the hohlraum target

Alumina ceramics, in which berlinite (aluminum orthophosphate, AlPO{sub 4}) is the bonding phase, were synthesized at 150 C. Differential thermal analysis of a mixture of Al{sub 2}O{sub 3} and H{sub 3}PO{sub 4} solution indicated that a minimum temperature of 118 C was necessary for a chemical reaction to occur. Therefore, we hydrothermally cured a mixture of Al{sub 2}O{sub 3} and H{sub 3}PO{sub 4} solution between 130 C and 150 C to form a hard and dense berlinite-bonded alumina ceramic. The intermediate phase of aluminum phosphate hydrate (AlH{sub 3}(PO{sub 4}){sub 2}H{sub 2}O) was also identified. Physical and mechanical properties of this material are discussed.

Gamma-radiation is frequently used as an analysis and characterization signal to monitor material in the nuclear fuel processing cycle. The selection as a diagnostic is self-evident since the radiation is ubiquitous, characteristic of the isotopes present, and sufficiently penetrating so that measurements may be made remotely. However, save through detector proximity or minimal collimation, the directional nature of the radiation is generally not used in traditional nondestructive assay (NDA) measurements. To demonstrate the additional information available, we used GRIS, the Gamma-Ray Imaging Spectrometer, at the K-25 and Portsmouth gaseous diffusion plants. In this facility, UF{sub 6} gas is enriched in heated equipment and piping which run inside an insulated housing. Occasionally, the process develops uranium deposits due to leakage of wet air or environmental changes within the housing that cause solidification of the process gas. When such deposits occur, traditional NDA techniques frequently require costly and time-consuming entry within the heat shielding to obtain precise information on the deposit unavailable from outside the shielding. In this paper we discuss GRIS, the gamma-ray imaging technique it uses, and present the results of measurements obtained on fuel processing equipment.

Simple methods for the cooling of the second crystals of cryogenically cooled undulator and wiggler double crystal monochromators are described. Copper braids between the first and second crystals are used to cool the second crystals of the double crystal monochromators. The method has proved successful for an undulator monochromator and we describe a design for a wiggler monochromator.

A laser guide star adaptive optics system is being built for the W. M. Keck Observatory`s 10-meter Keck II telescope. Two new near infra-red instruments will be used with this system: a high-resolution camera (NIRC 2) and an echelle spectrometer (NIRSPEC). The authors describe the expected capabilities of these instruments for high-resolution astronomy, using adaptive optics with either a natural star or a sodium-layer laser guide star as a reference. They compare the expected performance of these planned Keck adaptive optics instruments with that predicted for the NICMOS near infra-red camera, which is scheduled to be installed on the Hubble Space Telescope in 1997.

We are in the process of developing and building a laser system as the first in a series of a new generation of diode-pumped solid-state Inertial Confinement Fusion (ICF) lasers at LLNL (see Fig. 1 below). This laser system named �Mercury� will be the first integrated demonstration of a scalable laser architecture compatible with advanced high energy density (HED) physics applications. Primary performance goals include 10% efficiencies at 10 Hz and a 1- 10 ns pulse with lo energies of 100 J and with 2(omega)J/3(omega) frequency conversion.

Article on an experimental and theoretical study of the reaction between NH(X3Σ–) + SO(X3Σ–).

Accurate predictions of the performance of frequency conversion requires knowledge of the spatial variation of departures from the phase-matching condition in the converter crystals. This variation is caused by processes such as crystal growth and crystal surface finishing. Gravitational sag and mounting configurations also lead to deformation and stresses which cause spatially varying departures from the phase-matching condition. We have modeled the effect of gravitational forces on conversion efficiency performance of horizontal converter crystals and have shown for the NIF mounting configurations that gravity has very little effect on conversion efficiency. Keywords: Frequency conversion, ICF, Nonlinear optics, KDP crystals

This STI product consists of the Program/Abstracts book that was prepared for the participants in the Sixth International Conference on Biophysics and Synchrotron Radiation that was held August 4-8, 1998, at the Advanced Photon Source, Argonne National Laboratory. This book contains the full conference program and abstracts of the scientific presentations.

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Computers transfer data in a number of different ways. Whether through a serial port, a parallel port, over a modem, over an ethernet cable, or internally from a hard disk to memory, some data will be lost. To compensate for that loss, numerous error detection and correction algorithms have been developed. One of the most common error correction codes is the Reed-Solomon code, which is a special subset of BCH (Bose-Chaudhuri-Hocquenghem) linear cyclic block codes. In the AURA project, an unmanned aircraft sends the data it collects back to earth so it can be analyzed during flight and possible flight modifications made. To counter possible data corruption during transmission, the data is encoded using a multi-block Reed-Solomon implementation with a possibly shortened final block. In order to maximize the amount of data transmitted, it was necessary to reduce the computation time of a Reed-Solomon encoding to three percent of the processor's time. To achieve such a reduction, many code optimization techniques were employed. This paper outlines the steps taken to reduce the processing time of a Reed-Solomon encoding and the insight into modern optimization techniques gained from the experience.

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Fast Z-pinch technology developed on the Z machine at Sandia National Laboratories can produce up to 230 TW of thermal x-ray power for applications in inertial confinement fusion (ICF) and weapons physics experiments. During implosion, these Z-pinches develop Rayleigh-Taylor (R-T) instabilities which are very difficult to diagnose and which functionally diminish the overall pinch quality. The Power-Space-Time (PST) instrument is a newly configured diagnostic for measuring the pinch power as a function of both space and time in a Z-pinch. Placing the diagnostic at 90 degrees from the Z-pinch axis, the PST provides a new capability in collecting experimental data on R-T characteristics for making meaningful comparisons to magneto-hydrodynamic computer models. This paper is a summary of the PST diagnostic design. By slit-imaging the Z-pinch x-ray emissions onto a linear scintillator/fiber-optic array coupled to a streak camera system, the PST can achieve {approximately}100 {micro}m spatial resolution and {approximately}1.3 ns time resolution. Calculations indicate that a 20 {micro}m thick scintillating detection element filtered by 1,000 {angstrom} of Al is theoretically linear in response to Plankian x-ray distributions corresponding to plasma temperatures from 40 eV to 150 eV, By calibrating this detection element to x-ray energies up to 5,000 eV, the PST …

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