The aging tests conducted so far showed that duct tape tends to degrade in its performance as the joint it is applied to requires a geometrical description of a higher number of space dimensions (1-D, 2-D, 3-D). One-dimensional joints are the easiest to seal with duct tape, and thus the least to experience failure. Two-dimensional joints, such as the flexible duct core-to-collar joints tested in this study, are less likely to fail than three-dimensional collar-to-plenum joints, as the shrinkage could have a positive effect in tightening the joint. Three-dimensional joints are the toughest to seal and the most likely to experience failure. The 2-D flexible duct core-to-collar joints passed the six-month period of the aging test in terms of leakage, but with the exception of the foil-butyl tape, showed degradation in terms hardening, brittleness, partial peeling, shrinkage, wrinkling, delamination of the tape layers, flaking, cracking, bubbling, oozing and discoloration. The baking test results showed that the failure in the duct tape joints could be attributed to the type of combination of the duct tape and the material it is applied to, as the duct tape behaves differently with different substrates. Overall, the foil-butyl tape (Tape 4) had the best results, …

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This report compiles in a single source the Kd values measured with Hanford sediment for radionuclides and toxic compounds that have the greatest potential for driving risk to human health and safety in the vadose zone and groundwater at the Hanford Site.

By assuming a general isotropic pressure distribution P = P (y,a), where y and a are three-dimensional scalar functions labeling the field lines with B = -y x -a, we have derived a set of MHD eigenmode equations for both global MHD modes and field line resonances (FLR). Past MHD theories are restricted to isotropic pressures with P = P (y only). The present formulation also allows the plasma mass density to vary along the field line. The linearized ideal-MHD equations are cast into a set of global differential equations from which the field line resonance equations of the shear Alfvin waves and slow magnetosonic modes are naturally obtained for general three-dimensional magnetic field geometries with flux surfaces. Several new terms associated with the partial derivative of P with respect to alpha are obtained. In the FLR equations, a new term is found in the shear Alfvin FLR equation due to the geodesic curvature and the pressure gradient in the poloidal flux surface. The coupling between the shear Alfvin waves and the magnetosonic waves is through the combined effects of geodesic magnetic field curvature and plasma pressure as previously derived. The properties of the FLR eigenfunctions at the resonance field …

Numerical solutions for field line resonances (FLR) in the magnetosphere are presented for three-dimensional equilibrium magnetic fields represented by two Euler potentials as B = -j Y -a, where j is the poloidal flux and a is a toroidal angle-like variable. The linearized ideal-MHD equations for FLR harmonics of shear Alfvin waves and slow magnetosonic modes are solved for plasmas with the pressure assumed to be isotropic and constant along a field line. The coupling between the shear Alfvin waves and the slow magnetosonic waves is via the combined effects of geodesic magnetic field curvature and plasma pressure. Numerical solutions of the FLR equations are obtained for a quiet time magnetosphere as well as a disturbed time magnetosphere with a thin current sheet in the near-Earth region. The FLR frequency spectra in the equatorial plane as well as in the auroral latitude are presented. The field line length, magnetic field intensity, plasma beta, geodesic curvature and pressure gradient in the poloidal flux surface are important in determining the FLR frequencies. In general, the computed shear Alfvin FLR frequency based on the full MHD model is larger than that based on the commonly adopted cold plasma model in the beq > …

In this work we present temperature diagnostics of an expanding laser-produced argon plasma. A short-pulse (35fs) laser with an intensity of I = 10{sup 17}W/cm{sup 2} deposits {approx} 100 mJ of energy into argon clusters. This generates a hot plasma filament that develops into a cylindrically expanding shock. We develop spectral diagnostics for the temperatures of the argon plasma in the shock region and the preionized region ahead of the shock. A collisional-radiative model is applied to explore line intensity ratios derived from Ar II - Ar IV spectra that are sensitive to temperatures in a few eV range. The results of hydrodynamic simulations are employed to derive a time dependent radiative transport calculation that generates the theoretical emission spectra from the expanding plasma.

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Sub-Saharan Africa has been far more severely affected by AIDS than any other part of the world. The United Nations reports that 25.3 million adults and children are infected with the HIV virus in the region, which has about 10% of the world's population but more than 70% of the worldwide total of infected people. This report discusses this issue in detail, including the cause of the African AIDS epidemic, the social and economic consequences, response and treatment, and U.S. policy.

LBNL is pursuing a multi-divisional initiative that has this year further developed design studies and the scientific program for a facility dedicated to the production of x-ray pulses with ultra-short time duration. Our proposed x-ray facility [1] has the short x-ray pulse length ({approx};60 fs FWHM) necessary to study very fast dynamics, high flux (approximately 1011 photons/sec/0.1 percentBW) to study weakly scattering systems, and tuneability over 1-10 keV photon energy. The photon production section of the machine accomodates seven 2m long undulators and six 2T field dipole magnets. The x-ray pulse repetition rate of 10 kHz is matched to studies of dynamical processes (initiated by ultra-short laser pulses) that typicaly have a long recovery time or are not generally cyclic or reversible and need time to allow relaxation, replacement, or flow of the sample. The technique for producing ultra-short x-ray pulses uses relatively long electron bunches to minimise high-peak-current collective effects, and the ultimate x-ray duration is achieved by a combination of bunch manipulation and optical compression.

Accurate timing of ultrafast x-ray probe pulses emitted from a synchrotron radiation source with respect to a pump laser exciting processes in the sample under study is critical for the investigation of structural dynamics in the femtosecond regime. We describe a scheme for synchronizing femtosecond x-ray pulses relative to a pump laser. X-ray pulses of <100 fs duration are generated from a proposed source based on a recirculating superconducting linac [1,2,3]. Short x-ray pulses are obtained by a process of electron pulse compression, followed by transverse temporal correlation of the electrons, and ultimately x-ray pulse compression. Timing of the arrival of the x-ray pulse with respect to the pump laser is found to be dominated by the operation of the deflecting cavities which provide the transverse temporal correlation of the electrons. The deflecting cavities are driven from a highly stable RF signal derived from a modelocked laser oscillator which is also the origin of the pump l aser pulses.

The A2 LITE is a 2 liter, 2000 MPa, 750 K ultra-high pressure (UHP) vessel used to demonstrate UHP technology and to provide an air flow for wind tunnel nozzle development. It is the largest volume UHP vessel in the world. The design is based on a 100:1 pressure intensification using a hydraulic ram as a low pressure driver and a three-layer compound cylinder UHP section. Active control of the 900 mm piston stroke in the 63.5 mm bore permits pressure-time profiles ranging from static to constant pressure during flow through a 1 mm throat diameter nozzle for 1 second.

In this paper we study the validity of coupling impedance bench measurements for distributed impedances, comparing the commonly used log formula to the result obtained applying a modified version of Bethe's theory of diffraction to a long slot in a coaxial beam pipe. The equations found provide a quantitative expression for the influence of the wire thickness used in the measurement of the real and imaginary part of the longitudinal impedance. The precision achievable in an actual measurement is therefore discussed. The method presented has also been applied in the presence of lumped impedances [1].

We present a study of the single-bunch beam break up (BBU) instability for a proposed x-ray facility, based on a recirculating linac, to be built in Berkeley. The effects of injection errors, both position and angle, and of misalignments in the linac are investigated. We propose possible methods for limiting the consequent emittance increase.

Fe{sub 2}VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe{sub 2}VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy measurements showed that the carrier density and scattering time had little sample-to-sample variation or temperature dependence for near-stoichiometric samples. FTIR and DC resistivity suggest that the transport properties of Fe{sub 2}VAl are influenced by both localized and delocalized carriers, with the former primarily responsible for the negative temperature coefficient of resistivity. Magnetization measurements reveal that near-stoichiometric samples have superparamagnetic clusters with at least two sizes of moments. X-ray photoemission from Fe core level showed localized magnetic moments on site-exchanged Fe. They conclude that in Fe{sub 2}VAl, antisite disorder causes significant modification to the semi-metallic band structure proposed by LDA calculations. With antisite disorder considered, they are now able to explain most of the physical properties of Fe{sub 2}VAl.

This report describes the air pathway effects of Hanford Site operations from 1991 through 2000 on local air quality.

Alkali metal aluminohydrides have high potential as solid hydrogen storage materials. They have been known for their irreversible dehydrogenation process below 100 atm until Bogdanovic et al [1, 2] succeeded in the re-hydrogenation of NaAlH{sub 4} below 70 atm. They achieved 4 wt.% H{sub 2} reversible capacity by doping NaAlH{sub 4} with Ti and/or Fe organo-metalic compounds as catalysts. This suggests that other alkali and, possibly alkaline earth metal aluminohydrides can be used for reversible hydrogen storage when modified by proper dopants. In this research, Zr{sub 27}Ti{sub 9}Ni{sub 38}V{sub 5}Mn{sub 16}Cr{sub 5}, LaNi{sub 4.85}Sn{sub 0.15}, Al{sub 3}Ti, and PdCl{sub 2} were combined with LiAlH{sub 4} by ball-milling to study whether or not LiAlH{sub 4} is capable to both absorb and desorb hydrogen near ambient conditions. X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy were employed for sample characterizations. All four compounds worked as catalysts in the dehydrogenation reactions of both LiAlH{sub 4} and Li{sub 3}AlH{sub 6} by inducing the decomposition at lower temperature. However, none of them was applicable as catalyst in the reverse hydrogenation reaction at low to moderate hydrogen pressure.

The prescription of the initial conditions and the final conditions for a thermal accident for Type B packages are different for differing regulations. This paper presents an analytical method for estimating the effect of the boundary conditions on post-fire peak internal package temperatures. Results are given for several boundary conditions for a Type B drum-type package.

We have performed a series of experiments examining shock propagation in low density aerogels. High-pressure ({approx}100 kbar) shock waves are produced by detonating high explosives. Radiography is used to obtain a time sequence imaging of the shocks as they enter and traverse the aerogel. We compress the aerogel by impinging shocks waves on either one or both sides of an aerogel slab. The shock wave initially transmitted to the aerogel is very narrow and flat, but disperses and curves as it propagates. Optical images of the shock front reveal the initial formation of a hot dense region that cools and evolves into a well-defined microstructure. Structures observed in the shock front are examined in the framework of hydrodynamic instabilities generated as the shock traverses the low-density aerogel. The primary features of shock propagation are compared to simulations, which also include modeling the detonation of the high explosive, with a 2-D Arbitrary Lagrange Eulerian hydrodynamics code The code includes a detailed thermochemical equation of state and rate law kinetics. We will present an analysis of the data from the time resolved imaging diagnostics and form a consistent picture of the shock transmission, propagation and instability structure.

The corrosion resistance of Alloy 22 (UNS No.: N06022) was studied in 5 M CaCl{sub 2} electrolyte at various temperatures. Potentiodynamic polarization was used to examine the electrochemical behavior and measure the key potentials. Alloy 22 was found to be susceptible to localized corrosion in this high chloride [10M Cl{sup -}] environment at temperatures as low as 6O C.

In its current design, the high-level nuclear waste containers include an external layer of Alloy 22 (Ni-22Cr-13Mo-3W-3Fe). Since over their lifetime, the containers may be exposed to multi-ionic aqueous environments, a potential degradation mode of the outer layer could be environmentally assisted cracking (EAC). The objective of the current research was to characterize the effect of applied potential and temperature on the susceptibility of Alloy 22 to EAC in simulated concentrated water (SCW) using the slow strain rate test (SSRT). Results show that Alloy 22 may suffer EAC at applied potentials approximately 400 mV more anodic than the corrosion potential (E{sub corr}).

This study reports on the second phase (Phase II) of USGS research activities in support of DOE contract DE-AC22-95PC95101 ''Toxic Substances From Coal Combustion--A Comprehensive Assessment'', funded under DOE Interagency Agreement DE-AI22-95PC95145. The purpose of the study was to provide a quantitative and semi-quantitative characterization of the modes of occurrence of trace elements in coal samples investigated under Phase II, including (1) Ohio 5/6/7, an Ohio bituminous coal sample blended from the No.5, No.6, and No.7 beds; (2) North Dakota, a lignite sample from the Falkirk Mine, Underwood, ND, and (3) Wyodak, a sub-bituminous coal sample from the Cordero Mine, Gillette, WY. Samples from these coal beds were selected for their range in rank and commercial applicability. Results of this research provide basic information on the distribution of elements in Phase II coal samples, information needed for development of a commercial predictive model for trace-element behavior during coal combustion.

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Our proposed source for production of ultra-short (less than 100 fs FWHM) x-ray pulses utilizes a scheme for manipulation of the relatively long ({approx}2 ps) electron bunch in transverse phase-space, followed by compression of the emitted x-ray pulse in crystal optics [1]. In order to compress the x-ray pulses, RF cavities operating in a dipole mode (TM{sub 110}-like) are required to deflect the head and tail of a 2.5 GeV bunch in opposite directions. For a 2 ps duration electron bunch, an 8.5 MV deflecting voltage is required at a RF frequency of 3.9 GHz. In this paper, we will present a preliminary cavity design based on numerical simulations performed by MAFIA and URMEL codes. Seven-cell superconducting {pi} mode dipole RF cavities are proposed to provide the necessary deflecting voltage. Due to the presence of beam iris, the cavities operate in a hybrid mode where TM and TE like modes co-exist. Even on the beam axis, both magnetic and electric fields contribute to the transverse kick. Lower order monopole modes (LOMs) in the cavities may cause energy spread of the electron beam and need to be damped. The effects of the LOMs on beam dynamics are estimated. Possible damping schemes …