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We have developed a cleaning procedure for aluminum alloys for effective minimization of surface-adsorbed sub-micron particles and non-volatile residue. The procedure consists of a phosphoric acid etch followed by an alkaline detergent wash. To better understand the mechanism whereby this procedure reduces surface contaminants, we characterized the aluminum surface as a function of cleaning step using Surface Enhanced Raman Spectroscopy (SERS). SERS indicates that phosphoric acid etching re-establishes a surface oxide of different characteristics, including deposition of phosphate and increased hydration, while the subsequent alkaline detergent wash appears to remove the phosphate and modify the new surface oxide, possibly leading to a more compact surface oxide. We also studied the zeta potential of <5 micron pure aluminum and aluminum alloy 6061-T6 particles to determine how surface electrostatics may be affected during the cleaning process. The particles show a decrease in the magnitude of their zeta potential in the presence of detergent, and this effect is most pronounced for particles that have been etched with phosphoric acid. This reduction in magnitude of the surface attractive potential is in agreement with our observation that the phosphoric acid etch followed by detergent wash results in a decrease in surface-adsorbed sub-micron particulates.

Compressive and tensile stress in colloidal CdSe quantum dots (QDs) is examined using resonance Raman spectroscopy. We find that the dispersion of the longitudinal optical phonon mode with size does not follow theoretical calculations based on phonon confinement models. To account for these deviations, the presence of compressive or tensile stress in the QDs was proposed. We find that CdSe QDs prepared via a single source precursor (SSP) method exhibit compressive stress, while CdSe QDs prepared via high temperature lyothermal methods exhibit tensile stress. Evidence is provided that the SSP CdSe QDs stress is directly related to a surface effect.

The Defense Waste Processing Facility (DWPF), at the Savannah River Site is processing and immobilizing the radioactive high level waste sludge slurry at SRS into a durable borosilicate glass for final geological disposal. Each time a new batch of radioactive sludge is to be processed by the DWPF, the process flow sheet is to be tested and demonstrated to ensure an acceptable melter feed and glass can be made. These demonstrations are completed in the Shielded Cells Facility in the Savannah River National Laboratory at SRS.

The size dependent deformation potentials of CdSe quantum dots are studied by first principle and semi-empirical pseudopotentials calculations. They find that the amplitude of the quantum dot deformation potential is only slightly larger than the bulk value, and this increase is mostly caused by the off {Lambda} point deformation potentials in the bulk, which are larger in amplitude than the {Lambda} point deformation potential.

Inclusive W and Z production cross-sections have been measured by CDF and certain electroweak parameters extracted with high precision from these measurements. New results on diboson production at the Tevatron are also presented.

Run II at the Fermilab Tevatron Collider started in March 2001, and it will continue probing the high energy frontier in particle physics until the start of the LHC at CERN. The CDF collaboration at Fermilab has already stored 260 TB of data and expects to store 1PB of data in the next two years. The HEXCAF computing farm is being set up at Rutgers State University

Changes in the height of the tropopause provide a sensitive indicator of human effects on climate. A previous attempt to identify human effects on tropopause height relied on information from 'first-generation' reanalyses of past weather observations. Climate data from these initial model-based reanalyses have well-documented deficiencies, raising concerns regarding the robustness of earlier detection work that employed these data. Here, we address these concerns using information from the new second-generation ERA-40 reanalysis. Over 1979 to 2001, tropopause height increases by nearly 200 meters in ERA-40, partly due to tropospheric warming. The spatial pattern of height increase is consistent with climate model predictions of the expected response to anthropogenic influences alone, significantly strengthening earlier detection results. Atmospheric temperature changes in two different satellite datasets are more highly correlated with changes in ERA-40 than with those in a first-generation reanalysis, thus illustrating the improved quality of temperature information in ERA-40. Our results provide support for claims that human activities have warmed the troposphere and cooled the lower stratosphere over the last several decades of the 20th century, and that both of these changes in atmospheric temperature have contributed to an overall increase in tropopause height.

In the years 1998, 2000, and 2001, long-offset transientelectromagnetic (LOTEM) surveys were carried out at the active volcanoMerapi in Central Java. The measurements investigated the conductivitystructure of the volcanic edifice. Our area of interest, which is belowthe summit and the upper flanks, was investigated using horizontal andvertical magnetic field time derivative data from seventransmitter-receiver setups. Because of topography and athree-dimensional (3-D) underground structure, a 3-D interpretation isused. The method optimizes few parameters of a 3-D model by a stableleast squares joint inversion of the data, providing sufficientresolution capability. Reasonable data fits are achieved with anonhorizontally layered model featuring a very conductive basement belowdepths of 1.5 km. While hydrothermal alteration is also considered, wetentatively explain the high conductivities by aqueous solutions withrelatively high salt contents. A large magma body or a small superficialreservoir below Merapi's central volcanic complex, as discussed by otherauthors, cannot be resolved by the LOTEM data.

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Snow anomalies in the western United States (U.S.) have beenwidely investigated by many researchers due to its impact on wateravailability. This study focuses on how anomalous atmospheric circulationaffects snowpack accumulation in the western U.S. using observations andoutput from the National Center for Atmospheric Research (NCAR) CommunityClimate Model version 3 (CCM3). Our results indicate that themid-latitude atmospheric circulation anomalies induced by the ElNino-Southern Oscillation (ENSO) tend to drive winter precipitationshifts, leading to an anomalous snowpack distribution in the western U.S.The warm phase of ENSO produces increased snowpack in the Southwest,while the cold phase of ENSO generates increased snowpack in theNorthwest. Temperature has a secondary impact on the anomalous snowpackdistribution during ENSO episodes. Additionally, the non-linearatmospheric dynamics-related Pacific-North American (PNA) pattern isfound to strongly affect snow anomalies in the western U.S. independentfrom ENSO. The positive phase of the PNA pattern produces coldertemperature and stronger precipitation due to the lower pressure in theregion, leading to an above normal snowpack. Conversely, the negativephase of the PNA pattern generates warmer temperature and weakerprecipitation resulting from the higher pressure, producing a below thannormal snowpack in the western U.S. In general, the NCAR-CCM3 reproducesthe observed processes. However, model biases are identified andreported. The information provided in this …