Annually laminated sediments (varves) offer an effective means of acquiring high-quality paleoenvironmental records. However, the strength of a varve chronology can be compromised by a number of factors, such as missing varves, ambiguous laminations, and human counting error. We assess the quality of a varve chronology for the last three millennia from Steel Lake, Minnesota, through comparisons with nine AMS {sup 14}C dates on terrestrial plant macrofossils from the same core. These comparisons revealed an overall 8.4% discrepancy, primarily because of missing/uncountable varves within two stratigraphic intervals characterized by low carbonate concentrations and obscure laminations. Application of appropriate correction factors to these two intervals results in excellent agreement between the varve and {sup 14}C chronologies. These results, together with other varve studies, demonstrate that an independent age-determination method, such as {sup 14}C dating, is usually necessary to verify, and potentially correct, varve chronologies.

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Numerical weather prediction (NWP) models and atmospheric dispersion models rely on parameterizations of planetary boundary layer height. In the case of a stable boundary layer, errors in boundary layer height estimation can result in gross errors in boundary-layer evolution and in prediction of turbulent mixing within the boundary layer. We use large-eddy simulations (LES) of moderately stable boundary layers to characterize the effects of various physical processes on stable boundary layers. The stable boundary layer height is assumed to be a function of surface friction velocity, geostrophic wind, Monin-Obukhov length, and the strength of the temperature inversion atop the stable boundary layer. This temperature inversion induces gravity waves with a frequency determined by the strength of the temperature inversion.

There are underappreciated limitations of the conversion of {sup 14}C-ages to the fixed, calendrical time-scale that bear directly upon our understanding of the dynamic climate system, or the relationship between the collapse of one civilization and it's neighbor's. In this paper we present a quantitative assessment of the limits of {sup 14}C-geochronology and calibration onto the absolute calendrical time-scale over the Holocene. We take into account not only the inherent limitations of the {sup 14}C-calendar calibration curve, but also analytical uncertainties.

Atmospheric CO{sub 2} concentration ([CO{sub 2}]) is expected to rise from a current level of 372 {micro}mol mol{sup -1} to about 550 {micro}mol mol{sup -1} by the middle of the century (Prentice 2001). Accumulation of foliar carbohydrates is one of the most pronounced and universal changes observed in the leaves of C{sub 3} plants grown at elevated [CO{sub 2}] (Drake et al 1997). Carbohydrates are the product of photosynthetic cells and the substrate for sink metabolism. However, carbohydrates are not just substrates, changes in the composition and pool size of foliar carbohydrates have the potential to communicate source-sink balance and a role for carbohydrates in the regulation of the expression of many plant genes is well established (Koch 1996). Importantly, carbohydrate feedback is thought to be the mechanism through which long-term exposure to elevated [CO{sub 2}] leads to a reduction in carboxylation capacity (Rogers et a1 199S, Long et al 2004). Foliar sugar content has recently been linked to an increased susceptibility of soybeans to insect herbivory (Hamilton et al submitted). In addition increases in the C:N ratio of leaf litter of plants grown at elevated [CO{sub 2}] has been implicated in negative feedbacks on ecosystem productivity (Oechel et al …

We have performed two sets of experiments looking at laser-driven radiating blast waves. In one set of experiments the effect of a drive laser's passage through a background gas on the hydrodynamical evolution of blast waves was examined. It was found that the laser's passage heats a channel in the gas, creating a region where a portion of the blast wave front had an increased velocity, leading to the formation of a bump-like protrusion on the blast wave. The second set of experiments involved the use of regularly spaced wire arrays to induce perturbations on a blast wave surface. The decay of these perturbations as a function of time was measured for various wave number perturbations and found to be in good agreement with theoretical predictions.

The groundwater at the Nevada Test Site (NTS) contains many long-lived radionuclides, including {sup 99}Tc (technetium) and {sup 129}I (iodine), as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesized a body of data collected on the distribution of {sup 99}Tc and {sup 129}I in groundwater to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations up to forty years and under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results of our study show that Tc does not necessarily exist as a mobile and conservative species TcO{sub 4}{sup -}, as has been commonly assumed. This conclusion is corroborated by recent in situ redox potential measurements, which show that groundwaters at multiple locations of the NTS are not oxidizing, and mobility of reduced Tc species (TcO{sub 2} {center_dot} nH{sub 2}O) is greatly decreased. Speciation of iodine and its associated reactivity is also complex in the groundwater at the NTS, and its effect on the mobility of iodine should be the subject of future studies.

We present the status and initial images of a positrontomograph for prostate imaging that centers a patient between a pair ofexternal curved detector banks (ellipse: 45 cm minor, 70 cm major axis).The distance between detector banks adjusts to allow patient access andto position the detectors as closely as possible for maximum sensitivitywith patients of various sizes. Each bank is composed of two axial rowsof 20 CTI PET Systems HR+ block detectors for a total of 80 modules inthe camera. Compared to an ECAT HR PET system operating in 3D mode, ourcamera uses about one-quarter the number of detectors and hasapproximately the same sensitivity for a central point source, becauseour detectors are close to the patient. The individual detectors areangled in the plane to point towards the prostate to minimize resolutiondegradation in that region. The detectors are read out by modified CTIdata acquisition electronics. We have completed construction of thegantry and electronics, have developed detector calibration and dataacquisition software, and are taking coincidence data. We demonstratethat we can clearly visualize a "prostate" in a simple phantom.Reconstructed images of two phantoms are shown.

Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near …

Traditionally building simulation models are used at the design phase of a building project. These models are used to optimize various design alternatives, reduce energy consumption and cost. Building performance assessment for the operational phase of a buildings life cycle is sporadic, typically working from historical metered data and focusing on bulk energy assessment. Building Management Systems (BMS) do not explicitly incorporate feedback to the design phase or account for any changes, which have been made to building layout or fabric during construction. This paper discusses a proposal to develop an Industry Foundation Classes (IFC) compliant data visualization tool Building Performance Indicator (BuildingPI) for performance metric and performance effectiveness ratio evaluation.

During periods of drought when surface water supplies are severely limited, wildland forest fires tend to become more frequent and often can grow into major fires that threaten valuable timber, real estate, and even human lives. Fire-fighting crews are critically dependent upon accurate and timely weather data to help ensure that individuals are not inadvertently exposed to dangerous conditions and to enhance normal fire-fighting activities. To that end, the use of an eye-safe, portable lidar for remote wildland fire and smoke detection is described.

Current methods do not allow for sampling of in situ water from unsaturated fractures in low-moisture environments. A novel cryogenic coring technique based on the method developed by Simon and Cooper (1996) is used to collect in situ water in unsaturated fractures. This method uses liquid nitrogen as the drilling fluid, which can freeze the fracture water in place while coring. Laboratory experiments are conducted to demonstrate that water in an unsaturated fracture can be frozen and collected using cryogenic coring.

CIRCE (Coherent InfraRed CEnter) is a proposal for a new electron storage ring to be built at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL). The ring design is optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. Among others, CIRCE operation includes three interesting CSR modes: ultra stable, femtosecond laser slicing and broadband bursting. CSR allows CIRCE to generate an extremely high flux in the terahertz frequency region. The many orders of magnitude increase in the intensity over that presently achievable by conventional sources, has the potential to enable new science experiments. The characteristics of CIRCE and of the different modes of operation are described in this paper.

The new silicon detector design for CDF relies on advanced packaging solutions in order to attain the strict small size and low mass requirements dictated by the experiment's physics program. The silicon strip detector at CDF is composed of overlaying silicon sensors in the form of a barrel around the colliding beam. The electronic instrumentation (sensors, readout and transceiver chips) is assembled into the staves of this barrel. In this paper we describe the development of the mini port card (MPC). The MPC is located at one of the ends of the stave, and it is responsible for signal translation and repetition from the readout chips to and from the data acquisition system (DAQ). The MPC's development has taken two approaches that use different technologies. One of the approaches uses BeO as the board substrate (BeO-MPC), while the other approach uses a hybrid rigid-flexible polyimide substrate (Poly-MPC). We present test results of pre-production parts, each one assembled with a different MPC packaging technology. Complete thermal and electrical characterization of the MPC is shown, and the advantages and disadvantages of both technologies, as well as their influence in the overall system performance, are presented.

BL 7.2 is a new beamline at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed in the storage ring in August 2003 and commissioning with the ALS electron beam followed immediately after. In this paper the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization.

U.S. Department of Energy (DOE) nuclear facilities are categorized by the level of hazard they pose to workers, the general public, and the environment. This paper applies the methodology outlined in DOE-STD-1027-92 and interpreted in recent DOE guidance to a nuclear material storage facility at the Savannah River Site to reduce the category of the facility to below HC-3.

We show that CP asymmetries in b {yields} s hadronic decays are potentially affected by the presence of massive color-octet particles strongly coupled to the third generation quarks. Theories with warped extra dimensions provide natural candidates in the Kaluza-Klein excitations of gluons in scenarios where flavor-breaking by bulk fermion masses results in the localization of fermion wave-functions. Topcolor models, in which a new gauge interaction leads to top-condensation and a large top mass, also result in the presence of these color-octet states with TeV masses. We find that large effects are possible in modes such as B {yields} {phi}K{sub s}, B {yields} {eta}{prime}K{sub s} and B {yields} {pi}{sup 0}K{sub s} among others.

We present recent developments in design concepts for LUX - a source of ultra-short synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science [1]. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1-10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, independently tunable harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and resistive wall wakefields. Timing jitter between pump lasers and x-ray pulses is minimized by …

Residual radioactive waste was removed from Tank 18F in the F-Area Tank Farm at Savannah River Site (SRS), using the advanced design mixer pump (ADMP). Known as a slurry pump, the ADMP is a 55 foot long pump with an upper motor mounted to a steel super structure, which spans the top of the waste tank. The motor is connected by a long vertical drive shaft to a centrifugal pump, which is submerged in waste near the tank bottom. The pump mixes, or slurries, the waste within the tank so that it may be transferred out of the tank. Tank 18F is a 1.3 million gallon, 85 foot diameter underground waste storage tank, which has no internal components such as cooling coils or structural supports. The tank contained a residual 47,000 gallons of nuclear waste, consisting of a gelatinous radioactive waste known as sludge and particulate zeolite. The prediction of the ADMP success was based on nearly twenty five years of research and the application of that research to slurry pump technology. Many personnel at SRS and Pacific Northwest National Laboratories (PNNL) have significantly contributed to these efforts. This report summarizes that research which is pertinent to the ADMP performance …

CIRCE (Coherent InfraRed Center) at the Advanced Light Source, Lawrence Berkeley National Lab (LBNL), is a proposal for a new electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. One of the main requirement for this special mode of operation is the capability of the ring of operating at small momentum compaction values. In this regime, the longitudinal dynamics becomes strongly nonlinear and an accurate control of the higher order energy dependent terms of the momentum compaction is necessary. The lattice for CIRCE allows controlling the seterms up to the third order. The paper describes the lattice and presents the calculated performances in terms of momentum acceptance, dynamic aperture , lifetime and momentum compaction tune capabilities.

The Savannah River Site (SRS) is currently in the process of Deactivation and Decommissioning (D and D) several processing areas. This paper addresses the Material Control and Accountability (MC and A) activities that were developed and implemented to downgrade the material balance area (MBA) from an active Category I facility to an inactive Category IV MBA. MC and A downgrade requirements developed address topical areas that can impact final facility closure milestones. Final operational activities to process the remaining nuclear material in the facility needed to be coordinated with MC and A closure activities to minimize the amount of time and cost associated with the closure of the facility. MC and A activities that needed to be addressed included; the decommissioning of process areas, transfer of accountable nuclear material to other facilities, the material hold-up measurements required once process areas were shut down, the access requirements to nuclear material during the final processing and simultaneous closure of processing areas, the usage of enhanced material surveillance requirements to improve the utilization of Operations personnel, the updating and record retention for accountability records, the transition to a lower category MBA for final deactivation activities which included phasing out security force personnel, and …

Head-tail asymmetry has been observed in the longitudinal beam profiles in the Fermilab Recycler Ring where protons or antiprotons are stored in rf barrier buckets. The asymmetry is caused by the distortion of the rf potential well in the presence of resistive impedance. Gaussian energy distribution can fit the observed asymmetric beam profile but not without discrepancy. It can also fit the measured energy distribution. On the other hand, generalized elliptic distribution gives a better fit to the beam profile. However, it fails to reproduce the observed energy distribution.

Continuing advancements in software and hardware technology are providing facilities the opportunity for improvements in the areas of safety, regulatory compliance, administrative control, data collection, and reporting. Implementing these changes to improve plant operating efficiency can also create many challenges which include but are not limited to: justifying cost, planning for scalability, implementing applications across varied platforms, integrating multitudes of proprietary vendor applications, and creating a common vision for diverse process improvement projects. The Defense Programs (DP) facility at the Savannah River Site meets these challenges on a daily basis. Like many other plants, DP, has room for improvement when it comes to effective and clear communication, data entry, data storage, and system integration. Specific examples of areas targeted for improvement include: shift turnover meetings using system status data one to two hours old, lockouts and alarm inhibits performed on points on the Distributed Control System (DCS) and tracked in a paper logbook, disconnected systems preventing preemptive correction of regulatory compliance issues, and countless examples of additional task and data duplication on independent systems. Investment of time, money, and careful planning addressing these issues are already providing returns in the form of increased efficiency, improved plant tracking and reduced cost …

Waste removal from 49 underground storage tanks located in two tank farms involves three steps: bulk waste removal, water washing to remove residual waste, and in some cases chemical cleaning to remove additional residual waste. Not all waste can be completely removed by these processes-resulting in some residual waste loading following cleaning. Completely removing this residual waste would be prohibitively expensive; therefore, it will be stabilized by filling the tanks with grout. Acceptable residual waste loading inventories were determined using one-dimensional groundwater transport modeling to predict future human exposure based on several scenarios. These modeling results have been incorporated into a geographic information systems (GIS) application for rapid evaluation of various tank closure options.