None

None

None

The large electron affinity of InN, close to 6 eV and the largest of any III-V semiconductor, creates a strong driving force for native donor formation, both in the bulk and at surfaces and interfaces. Moreover, all InN surfaces, regardless of crystal orientation or doping, have been observed to have a surface accumulation layer of electrons, which interferes with standard electrical measurements. For these reasons, until recently, it was uncertain whether or not compensation by donor defects would prevent “real” p-type activity (i.e. existence of sufficiently shallow acceptors and mobile holes). A coordinated experimental approach using a combination of electrical (Hall effect) and electrothermal (Seebeck coefficient) measurements will be described that allows definitive evaluation of carrier transport in InN. In Mg-doped InN films, the sensitivity of thermopower to bulk hole conduction, combined with modeling of the parallel conducting layers (surface/bulk/interface), enables quantitative measurement of the free hole concentration and mobility. In undoped (n-type) material, combined Hall and thermopower measurements, along with a considering of the scattering mechanisms, leads to a quantitative understanding of the crucial role of charged line defects in limiting electron transport.

We discuss linear and nonlinear optical wave propagation in a left-handed medium (LHM) or medium of negative refraction (NRM). We use the approach of characterizing the medium response totally by a generalized electric polarization (with a dielectric permittivity {tilde {var_epsilon}}(w, {rvec k})) that can be decomposed into a curl and a non-curl part. The description has a one-to-one correspondence with the usual approach characterizing the LHM response with a dielectric permittivity {var_epsilon}<0 and a magnetic permeability {mu}<0. The latter approach is less physically transparent in the optical frequency region because the usual definition of magnetization loses its physical meaning. Linear wave propagation in LHM or NRM is characterized by negative refraction and negative group velocity that could be clearly manifested by ultra-short pulse propagation in such a medium. Nonlinear optical effects in LHM can be predicted from the same calculations adopted for ordinary media using our general approach.

This paper introduces a hierarchy of electron pseudomoment fluid equations that is used to derive electron Landau damping of ion acoustic waves.

Seismic stress analyses of plant piping systems usually ignore the possibility of reduced joint strength due to weld imperfections. This paper presents a method that might be used to assess the impact of weld imperfections in a piping system, provided that limited destructive examination of welded joints is possible. A probability distribution function of weld quality is developed from the destructive examination, and this is combined with an experimentally determined relationship between weld quality and reduced strength. This latter is the result of uniaxial tensile testing of specimens with controlled imperfections. A seismic stress probability distribution function is determined by conventional seismic analysis. The above quantities are used to quantify the conditional failure probability of the imperfect weld. Effect of imperfection distribution within a given weld on the probability of failure is discussed.

A surface resistivity survey was conducted on the Hanford Site over a waste disposal trench that received a large volume of liquid inorganic waste. The objective of the survey was to map the extent of the plume that resulted from the disposal activities approximately 50 years earlier. The survey included six resistivity transects of at least 200m, where each transect provided two-dimensional profile information of subsurface electrical properties. The results of the survey indicated that a low resistivity plume resides at a depth of approximately 25-44 m below ground surface. The target depth was calibrated with borehole data of pore-water electrical conductivity. Due to the high correlation of the pore-water electrical conductivity to nitrate concentration and the high correlation of measured apparent resistivity to pore-water electrical conductivity, inferences were made that proposed the spatial distribution of the apparent resistivity was due to the distribution of nitrate. Therefore, apparent resistivities were related to nitrate, which was subsequently rendered in three dimensions to show that the nitrate likely did not reach the water table and the bounds of the highest concentrations are directly beneath the collection of waste sites.

In a previous humorous note entitled 'Twelve Ways to Fool the Masses,' I outlined twelve common ways in which performance figures for technical computer systems can be distorted. In this paper and accompanying conference talk, I give a reprise of these twelve 'methods' and give some actual examples that have appeared in peer-reviewed literature in years past. I then propose guidelines for reporting performance, the adoption of which would raise the level of professionalism and reduce the level of confusion, not only in the world of device simulation but also in the larger arena of technical computing.

The Genome-Linked Application for Metabolic Maps (GLAMM) is a unified web interface for visualizing metabolic networks, reconstructing metabolic networks from annotated genome data, visualizing experimental data in the context of metabolic networks, and investigating the construction of novel, transgenic pathways. This simple, user-friendly interface is tightly integrated with the comparative genomics tools of MicrobesOnline. GLAMM is available for free to the scientific community at glamm.lbl.gov.

The fission reaction has been observed with high energy accelerator projectiles for elements as light as tantalum but has not been reported for medium weight elements. The present note presents evidence for the occurrence of reactions which are probably most properly described by the term 'fission' and which seem to occur with very small yield throughout the region where this type of reaction is only slightly exoergic or even endoergic with respect to mass balance. In the course of detailed investigation of the spallation of copper and the variation of the product yields with energy of the bombarding particle the threshold for formation of radioactive Cl{sup 38} (38-minute half-life) from elemental studied. The energetically most economical way in which Cl{sup 38} might be spallation reactions is by emission from the bombarded copper nucleus of nucleons in groups such as alpha-particles instead of single nucleons 0 The energetic requirements for the reaction Cu{sup 63}(p,pn6a)Cl{sup 38}, in which the maximum number of alpha-particles are emitted, include (1) the mass difference between the reactants and the products and (2) the excitation energy which the alpha-particles must have in order to pass over the coulombic barrier, Since the reaction is endoergic with respect to …

A method is described for determination of free acid in solutions containing the hydrolyzable ions Al (III), Cr(III), Fe(III), Hg(II), Ni(II), Th(IV), and U(VI). The concentration of the sample is calculated either by solving three simultaneous Nernst equations, by the Gran plot procedure, or by means of a microprocessor pH meter. Molar concentrations of metal ion up to 2.5 times that of the acid can be tolerated. The method has been applied to analysis of nuclear processing solutions that contain Pu(III), in addition to the ions listed above.

The detection capabilities of the new U-232/Th-228 source are comparable to those of the Na-24 source. The main benefit in using the new source is the ease of operation. Elimination of the neutron activation step required for Na-24 sources saves about 24 hours in planning, scheduling, and executing. With the new U-232/Th-228 source, the monitor can be put in operation in less than 15 minutes. The long half-life of the U-232/Th-228 source also eliminates the need to record calibration and measurement times, as required for decay corrections when using a Na-24 source.

Ten heat pump water heaters (HPWH) were placed in an environmentally controlled test facility and run through a durability test program of approximately 7300 duty cycles (actual cycles accumulated ranged from 6640 to 8324 for the ten units). Five of the units were upgraded integral types (HPWH mounted on storage tank, no pump) from the same manufacturer as those tested in our first durability program in 2001 (Baxter and Linkous, 2002). The other five were ''add-on'' type units (HPWH with circulation pump plumbed to a separate storage tank) from another manufacturer. This durability test was designed to represent approximately 7-10 years of normal operation to meet the hot water needs of a residence. The integral units operated without incident apart from two control board failures. Both of these were caused by inadvertent exposure to very hot and humid (>135 F dry bulb and >120 F dew point) conditions that occurred due to a test loop failure. It is not likely that any residential water heater would be installed where such conditions were expected so these failures are not considered a long-term reliability concern. Two of the integral HPWHs featured a condensate management system (CMS) option that effectively eliminated any need …

None

This document summarizes the information on the historical uses, present status, and the sampling and analysis results of waste stored in Tank 241-AW-102. This report supports the requirements of the Tri-Party Agreement Milestone M-44-05.

The objectives of this project are to design, assemble, test, and demonstrate a prototype Internal Reflection Sensor (IRS) for the cone penetrometer. The sensor will ultimately be deployed during site characterization with the goal of providing real-time, in situ detection of NonAqueous Phase Liquids (NAPLs) in the subsurface. In the first phase of this program, we have designed and assembled an IRS module that interfaces directly to a standard cone penetrometer system. Laboratory tests demonstrated that the sensor responds in real-time to a wide variety of free phase NAPLs without interference from natural materials such as water and soil of various types or dissolved contaminants. In a preliminary field test, the sensor was able to locate NAPLs at thin, discrete depths in a soil test pit when deployed with a cone penetrometer. Ruggedness of the device was tested with a series of penetrometer pushes to the depth of refusal at a clean location. There was no visible damage to the sensor and its performance did not change in the course of these experiments. Based on the successes of the Phase I program, it is recommended that the project proceed to full-scale demonstration in Phase II.

This document summarizes the information on the historical uses, present status, and the sampling and analysis results of waste stored in Tank 241-B-109. This tank has been listed on the Organic Salts Watch List. This-report supports the requirements of the Tri-Party Agreement Milestone M 44-10.

This document describes the testing performed by ARD Environmental, Inc., and Los Alamos Technical Associates of the LATA/ARD Advanced Sluicing System, in support of ACTR Phase 1 activities. Testing was to measure the impact force and pressures of sluicing streams at three different distances, as measured by the Government supplied load cell. Simulated sluicing of large simulated salt cake and hard pan waste coupons was also performed. Due to operational difficulties experienced with the Government supplied load cell, no meaningful results with respect to sluice stream impact pressure distribution or stream coherence were obtained. Sluice testing using 3000 psi salt cake simulants measured waste retrieval rates of approximately 12 Ml/day (17.6 ft{sup 3}/hr). Rates as high as 314 m{sup 3}/day (463 ft{sup 3}/hr) were measured against the lower strength salt cake simulants.

Long reach arms represent one of the options available for deployment of end effectors which can be used in the retrieval of radioactive waste, from the Hanford single shell tanks. The versatility of an arm based deployment system is such that it has the potential to improve the performance of a wide range of end effectors compared with stand-alone or other deployment methods. The long term reliability and availability of the deployment system is central to the timely completion of a waste retrieval program. However, concerns have been expressed over the dynamic performance of long reach arms and it is essential that an arm based system can cope with operational dynamic loads generated by end effectors. The test program conducted set out to measure static and dynamic loads and responses from a representative arm and sluicer, with the objective of extrapolating the data to a long reach arm system, that can be used for in-tank waste retrieval. As an arm with an appropriate reach was not available, the test program was undertaken to measure dynamic characteristics of a Magnox Electric 18 ft multi-link, hydraulically actuated SNAKES manipulator. This is the longest reach unit in service, albeit only one third of …

Magnetic switching offers an alternative to overcoming the rep-rate and life limitations of the spark gaps in the ETA/ATA induction accelerators. The principle has been applied for many years to radar modulators but at much lower power levels and longer pulse lengths. Comparatively recent developments in magnetic materials together with some optimal circuits have made it possible to go well beyond the state of the art. A magnetic modulator has been built which steps up and compresses a 25 kV, 5 ..mu..s pulse into a 250 kV, 50 ns pulse. A second magnetic modulator has been built and installed to replace four Blumleins and spark gaps in order to provide triggers for the complete ETA injector and accelerator. The paper outlines some practical and theoretical considerations affecting the design of the magnetic pulse generator.

Preparation of enriched fuel elements and target (N) elements for a full H-Reactor E-N demonstration loading was authorized in April, 1960. The objective of this loading was to demonstrate the feasibility of operating a Hanford reactor economically as a plutonium-tritium producer to increase over-all conversion ratio and diversify product output. Irradiation of the E-N load began in May, 1961 and was completed in January, 1962.

Although there are many differences between the High-Temperature Gas Cooled Reactor (HTGR) concepts being developed in the US and the High Temperature Reactor (HTR) concepts in the Federal Republic of Germany (FRG), the coated fuel particles are very similar. Significant benefits are achievable through cooperative research and exchange of information and data on the fuel performance and radionuclide retention in the coated fuel particles. This draft report describes cooperative work on HTGR safety research as agreed to in the "USA/FRG Umbrella Agreement for Cooperation in GCR Development: Safety Research Subprogram Plan," specifically, this work was conducted under Project Work Statement (PWS) S-6 titled "Fission Product Retention in Fuel," 9 refs., 12 figs., 4 tabs.

None