The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50-60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

The Next Generation Nuclear Plant (NGNP) is a high temperature gas-cooled reactor that will be capable of producing hydrogen, electricity and/or high temperature process heat for industrial use. The project has initiated the conceptual design phase and when completed will demonstrate the viability of hydrogen generation using nuclear produced process heat. This paper explains how industry and the U.S. Government are cooperating to advance nuclear hydrogen technology. It also describes the issues being explored and the results of recent R&D including materials development and testing, thermal-fluids research, and systems analysis. The paper also describes the hydrogen production technologies being considered (including various thermochemical processes and high-temperature electrolysis).

Lithium borohydride, magnesium hydride and the 2:1 'destabilized' ball milled mixtures (2LiBH{sub 4}:MgH{sub 2}) underwent liquid phase hydrolysis, gas phase hydrolysis and air oxidation reactions monitored by isothermal calorimetry. The experimentally determined heats of reaction and resulting products were compared with those theoretically predicted using thermodynamic databases. Results showed a discrepancy between the predicted and observed hydrolysis and oxidation products due to both kinetic limitations and to the significant amorphous character of observed reaction products. Gas phase and liquid phase hydrolysis were the dominant reactions in 2LiBH{sub 4}:MgH{sub 2} with approximately the same total energy release and reaction products; liquid phase hydrolysis displayed the maximum heat flow for likely environmental exposure with a peak energy release of 6 (mW/mg).

The hyperfine-induced 2s2p {sup 3}P{sub 0}-2s{sup 2} {sup 1}S{sub 0} transition rate for Be-like {sup 47}Ti{sup 18+} was recently measured in a storage-ring experiment by Schippers et al. [Phys. Rev. Lett. 98, 033001 (2007)]. The measured value of 0.56(3) s{sup -1} is almost 60% larger than the theoretical value of 0.356 s{sup -1} from a multiconfiguration Dirac-Fock calculation by Marques et al. [Phys. Rev. A 47, 929 (1993)]. In this work, we use a large-scale relativistic configuration-interaction method to calculate these hyperfine-induced rates for ions with Z = 6-92. Coherent hyperfine-quenching effects between the 2s2p {sup 1,3}P{sub 1} states are included in a perturbative as well as a radiation damping approach. Contrary to the claims of Marques et al., contributions from the {sup 1}P{sub 1} state are substantial and lead to a hyperfine-induced rate of 0.67 s{sup -1}, in better agreement with, though larger than, the measured value.

In order to efficiently perform particle simulations in systems with widely varying magnetization, we have developed a 'drift-Lorentz mover', which interpolates between full particle dynamics and drift kinetics in such a way as to preserve a physically correct gyroradius and particle drifts for both large and small ratios of the timestep to the cyclotron period. In order to extend applicability of the mover to systems with plasma frequency exceeding the cyclotron frequency - such as one may have with fully neutralized drift compression of a heavy ion beam - we have developed an implicit version of the mover. A first step in this direction, in which the polarization charge was added to the field solver, was described previously. Here we describe a fully implicit algorithm (which is analogous to the direct-implicit method for conventional particle-in-cell simulation), a stability analysis of it, its implementation in the WARP code, and several tests of the resultant code. The fully implemented version is electrostatic; we are beginning development of an electromagnetic version, and describe also the status of that effort.

Automated front-end sample preparation technologies can significantly enhance the sensitivity and reliability of biodetection assays [1]. We are developing advanced sample preparation technologies for biowarfare detection and medical point-of-care diagnostics using microfluidic systems with continuous sample processing capabilities. Here we report an electrophoretically assisted acoustic focusing technique to rapidly extract and enrich viral and bacterial loads from 'complex samples', applied in this case to human nasopharyngeal samples as well as simplified surrogates. The acoustic forces capture and remove large particles (> 2 {micro}m) such as host cells, debris, dust, and pollen from the sample. We simultaneously apply an electric field transverse to the flow direction to transport small ({le} 2 {micro}m), negatively-charged analytes into a separate purified recovery fluid using a modified H-filter configuration [Micronics US Patent 5,716,852]. Hunter and O'Brien combined transverse electrophoresis and acoustic focusing to measure the surface charge on large particles, [2] but to our knowledge, our work is the first demonstration combining these two techniques in a continuous flow device. Marina et al. demonstrated superimposed dielectrophoresis (DEP) and acoustic focusing for enhanced separations [3], but these devices have limited throughput due to the rapid decay of DEP forces. Both acoustic standing waves and electric fields …

Pyrgeometers are used to measure the atmospheric longwave irradiance throughout the ARM program sites. Previous calibrations of pyrgeometers using ARM/Eppley/NREL blackbody were consistent, but introduced a difference in the historical clear sky measured irradiance. This difference was believed to be in the order of 12 W/m2. In this poster we show the improvements to the blackbody and calibration methodology by comparing our results to the results of a group of pyrgeometers that were recently calibrated against the World Infrared Standard Group, in the World Radiation Center, Davos/Switzerland.

Highly crystalline samples of LiMnPO{sub 4} and its analogs with partial substitution of Mn by divalent Mg, Cu, Zn, and Ni were prepared by hydrothermal synthesis and characterized by x-ray diffraction and infrared spectroscopy. Chemical oxidation produced two-phase mixtures of the initial phases LiMn{sub (1-y)}M{sub y}PO{sub 4} and the delithiated forms, Li{sub y}Mn{sub (1-y)}M{sub y}PO{sub 4}, all with the olivine structure. The extent of oxidation depended upon the quantity of oxidizing agent used and on the identity of the substituent ions. Mg, Ni and Cu were found to increase the level of delithation relative to that in pure LiMnPO{sub 4}. Mg was also shown to reduce the tendency of the oxidized phase to absorb water.

Two-channel final-state interaction problem is exactly solved and applied to the B meson decay.

This paper presents the influence of conventional wind turbine blade-pitch control actions on the pitch damping of a wind turbine supported by an offshore floating barge with catenary moorings.

The background in the BaBar detector is especially high during injection, when most components are actually having reduced voltages. The situation is worse for the beam in High Energy Ring (HER) when the LER beam is present. It was found that the transverse feedback system plays an important role when stacking more charge on top of existing bunches. Lowering the feedback gain helped and it was realized later that the best scenario would be to gate off the feedback for only the one bunch, which got additional charge injected into it. The explanation is that the blown-up, but centered, original HER bunch plus the small injected off-axis bunch (each with half the charge) would stay in the ring if not touched, but the feedback system sees half the offset and wants to correct it, therefore disturbing and scraping the blown-up part.

High β plasmas in the National Spherical Torus Experiment (NSTX) operate in the overdense regime, allowing the electron Bernstein wave (EBW) to propagate and be strongly absorbed/emitted at the electron cyclotron resonances. As such, EBWs may provide local electron heating and current drive. For these applications, efficient coupling between the EBWs and electromagnetic waves outside the plasma is needed. Thermal EBW emission (EBE) measurements, via oblique B-X-O double mode conversion, have been used to determine the EBW transmission efficiency for a wide range of plasma conditions on NSTX. Initial EBE measurements in H-mode plasmas exhibited strong emission before the L-H transition, but the emission rapidly decayed after the transition. EBE simulations show that collisional damping of the EBW prior to the mode conversion (MC) layer can significantly reduce the measured EBE for Te < 20 eV, explaining the observations. Lithium evaporation was used to reduce EBE collisional damping near the MC layer. As a result, the measured B-X-O transmission efficiency increased from < 10% (no Li) to 60% (with Li), consistent with EBE simulations.

The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.

A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light Source at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output recording camera. With an initial wavelength range of 1500–4500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera array’s sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled …

The feasibility to coat large SNF/HLW containers with a structurally amorphous material (SAM) was demonstrated on sub-scale models fabricated from Type 316L stainless steel. The sub-scale model were coated with SAM 1651 material using kerosene high velocity oxygen fuel (HVOF) torch to thicknesses ranging from 1 mm to 2 mm. The process parameters such as standoff distance, oxygen flow, and kerosene flow, were optimized in order to improve the corrosion properties of the coatings. Testing in an electrochemical cell and long-term exposure to a salt spray environment were used to guide the selection of process parameters.

The Java Metadata Facility is introduced by Java Specification Request (JSR) 175 [1], and incorporated into the Java language specification [2] in version 1.5 of the language. The specification allows annotations on Java program elements: classes, interfaces, methods, and fields. Annotations give programmers a uniform way to add metadata to program elements that can be used by code checkers, code generators, or other compile-time or runtime components. Annotations are defined by annotation types. These are defined the same way as interfaces, but with the symbol {at} preceding the interface keyword. There are additional restrictions on defining annotation types: (1) They cannot be generic; (2) They cannot extend other annotation types or interfaces; (3) Methods cannot have any parameters; (4) Methods cannot have type parameters; (5) Methods cannot throw exceptions; and (6) The return type of methods of an annotation type must be a primitive, a String, a Class, an annotation type, or an array, where the type of the array is restricted to one of the four allowed types. See [2] for additional restrictions and syntax. The methods of an annotation type define the elements that may be used to parameterize the annotation in code. Annotation types may have default …

Laboratory experiments were conducted at gas turbine and atmospheric conditions (0.101 < P{sub 0} < 0.810 MPa, 298 < T{sub 0} < 580K, 18 < U{sub 0} < 60 m/s) to characterize the overall behaviors and emissions of the turbulent premixed flames produced by a low-swirl injector (LSI) for gas turbines. The objective was to investigate the effects of hydrogen on the combustion processes for the adaptation to gas turbines in an IGCC power plant. The experiments at high pressures and temperatures showed that the LSI can operate with 100% H{sub 2} at up to {phi} = 0.5 and has a slightly higher flashback tolerance than an idealized high-swirl design. With increasing H{sub 2} fuel concentration, the lifted LSI flame begins to shift closer to the exit and eventually attaches to the nozzle rim and assumes a different shape at 100% H{sub 2}. The STP experiments show the same phenomena. The analysis of velocity data from PIV shows that the stabilization mechanism of the LSI remains unchanged up to 60% H{sub 2}. The change in the flame position with increasing H{sub 2} concentration is attributed to the increase in the turbulent flame speed. The NO{sub x} emissions show a log …

Previous lattice designs for the Next Linear Collider Main Damping Rings [1] have met the specifications for equilibrium emittance, damping rate and dynamic aperture. Concerns about the effects of the damping wiggler on the beam dynamics [2] led to the aim of reducing the total length of the wiggler to a minimum consistent with the required damping rate, so high-field dipoles were used to provide a significant energy loss in the arcs. However, recent work has shown that the wiggler effects may not be as bad as previously feared. Furthermore, other studies have suggested the need for an increased momentum compaction (by roughly a factor of four) to raise the thresholds of various collective effects. We have therefore developed a new lattice design in which we increase the momentum compaction by reducing the field strength in the arc dipoles, compensating the loss in damping rate by increasing the length of the wiggler. The new lattice again meets the specifications for emittance, damping rate and dynamic aperture, while having the benefit of significantly higher thresholds for a number of instabilities.

The reality of multi-core hardware has made concurrent programs pervasive. Unfortunately, writing correct concurrent programs is dif#2;cult. Addressing this challenge requires advances in multiple directions, including concurrency bug detection, concurrent program testing, concurrent programming model design, etc. Designing effective techniques in all these directions will signi#2;cantly bene#2;t from a deep understanding of real world concurrency bug characteristics. This paper provides the #2;rst (to the best of our knowledge) comprehensive real world concurrency bug characteristic study. Specifically, we have carefully examined concurrency bug patterns, manifestation, and #2;x strategies of 105 randomly selected real world concurrency bugs from 4 representative server and client opensource applications (MySQL, Apache, Mozilla and OpenOf#2;ce). Our study reveals several interesting #2;ndings and provides useful guidance for concurrency bug detection, testing, and concurrent programming language design. Some of our #2;ndings are as follows: (1) Around one third of the examined non-deadlock concurrency bugs are caused by violation to programmers' order intentions, which may not be easily expressed via synchronization primitives like locks and transactional memories; (2) Around 34% of the examined non-deadlock concurrency bugs involve multiple variables, which are not well addressed by existing bug detection tools; (3) About 92% of the examined concurrency bugs can be reliably …

Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum ina cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16 100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32 200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable"sensitive volumes."

Binary Pt/Pd nanoparticles were synthesized by localized overgrowth of Pd on cubic Pt seeds for the investigation of electrocatalytic formic acid oxidation. The binary particles exhibited much less self-poisoning and a lower activation energy relative to Pt nanocubes, consistent with the single crystal study.

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Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a 50 m section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center.

Experiment E949 at Brookhaven National Laboratory studied the rare decay K{sup +}-->pi{sup +} nu{ovr {nu}} and other processes with an exposure of 1.77 x 10{sup 12} k{sup +}'s. The data were analyzed using a blind analysis technique yielding one candidate event with an estimated background of 0.30 {+-} 0.03 events. Combining this result with the observation of two candidate events by the predecessor experiment E787 gave the branching ratio B(K{sup +}-->pi{sup +} nu{ovr {nu}}) = (1.47{sub -0.89}{sup +1.30}) x 10{sup -10}, consistent with the standard model prediction of (0.74 {+-} 0.20) x 10{sup -10}. This is a more detailed report of results previously published [V.V. Anisimovsky et al., Phys. Rev. Lett. 93, 031801 (2004)].