The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher …

A field investigation of unsaturated flow through a lithophysal unit of fractured welded tuff containing lithophysal cavities has been initiated. To characterize flow in this spatially heterogeneous medium, a systematic approach has been developed to perform tests in boreholes drilled at regular intervals in an underground tunnel (drift). In this paper, we describe the test equipment system that has been built for this purpose. Since the field-scale measurements, of liquid flow in the unsaturated, fractured rocks, require continuous testing for periods of days to weeks, the control of test equipment has been fully automated, allowing operation with no human presence at the field site. Preliminary results from the first set of tests are described. These tests give insight into the role of the matrix (perhaps also lithophysal cavities) as potential storage during the initial transient flow prior to the breakthrough of water at the drift crown, as well as the role of connected fractures that provide the subsequent quasi-steady flow. These tests also reveal the impact of evaporation on seepage into the drift.

The purpose of this calculation is to quantify previously unquantified uncertainties associated with the Drift Degradation Analysis (BSC 2001b). The results from this calculation will support the development of a technical report to document supplemental science and performance analyses. This calculation has been developed according to the guidance provided by the ''Technical Work Plan for EBS Department Modeling FY 01 Work Activities'' (BSC 2001a). The specific objective of this calculation is to perform sensitivity studies to assess the impact of the following parameters on rock fall results: (1) parameter M, a multiplier of fracture trace lengths sampled from field data; (2) Terzaghi correction factor for subhorizontal fractures; and (3) number of Monte Carlo simulations. The scope of this calculation includes using the fracture data inputs from the ''Drift Degradation Analysis'' (BSC 2001b) as input to the Discrete Region Key Block Analysis (DRKBA) numerical code. Outputs from this program includes the expected quantities and size distributions of failed rock blocks. This calculation is applicable to unsupported drifts without backfill. This calculation is associated with the engineering and performance analysis activities of the Engineered Barrier System Department, and was developed in accordance with AP-3.12Q, ''Calculations''.

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit 168 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 168 consists of a group of twelve relatively diverse Corrective Action Sites (CASs 25-16-01, Construction Waste Pile; 25-16-03, MX Construction Landfill; 25-19-02, Waste Disposal Site; 25-23-02, Radioactive Storage RR Cars; 25-23-18, Radioactive Material Storage; 25-34-01, NRDS Contaminated Bunker; 25-34-02, NRDS Contaminated Bunker; CAS 25-23-13, ETL - Lab Radioactive Contamination; 25-99-16, USW G3; 26-08-01, Waste Dump/Burn Pit; 26-17-01, Pluto Waste Holding Area; 26-19-02, Contaminated Waste Dump No.2). These CASs vary in terms of the sources and nature of potential contamination. The CASs are located and/or associated wit h the following Nevada Test Site (NTS) facilities within three areas. The first eight CASs were in operation between 1958 to 1984 in Area 25 include the Engine Maintenance, Assembly, and Disassembly Facility; the Missile Experiment Salvage Yard; the Reactor Maintenance, Assembly, and Disassembly Facility; the Radioactive Materials Storage Facility; and the Treatment Test Facility Building at Test Cell A. Secondly, the three CASs located in …

The use of sprayed flammable fluids as solvents in dissolution and cleaning processes demand detailed understanding of ignition and fire hazards associated with these applications. When it is not feasible to inert the atmosphere in which the spraying process takes place, then elimination of all possible ignition sources must be done. If operators are involved in the process, the potential for human static build-up and ultimate discharge is finite, and it is nearly impossible to eliminate. The specific application discussed in this paper involved the use of heated Dimethyl Sulfoxide (DMSO) to dissolve high explosives (HE). Search for properties of DMSO yielded data on flammability limits and flash point, but there was no published information pertaining to the minimum energy for electrical arc ignition. Due to the sensitivity of this procedure, The Hazards Control Department of Lawrence Livermore National Laboratory (LLNL) was tasked to determine the minimum ignition energy of DMSO aerosol and vapor an experimental investigation was thus initiated. Because there were no electrical sources in spray chamber, Human Electro-Static Discharge (HESD) was the only potential ignition source. Consequently, the electrostatic generators required for this investigation were designed to produce electrostatic arcs with the defined voltage and current pulse …

Currently, data of interest to microbial researchers is spread across hundreds of web-accessible data sources, each with a unique interface and data format. Researchers interact with a few of these sites when they analyze their data, but are not able to utilize the majority of them on a regular basis. There are two significant challenges that must be overcome to integrate this environment and allow researchers to efficiently perform data analysis across the entire set of relevant data, or at least a significant portion of it. The first is to provide consistent access to the large numbers of distributed, heterogeneous data sets that are currently distributed over the web. The second is to define the semantics of the data provided by the individual sites in such a way that semantic conflicts can be identified and, ideally, resolved. The first step in establishing any integrated environment, from a data warehouse to a multi-database system, is provide consistent access to all of the relevant sources. While the type of access required will vary based on the integration strategy chosen--for example federated systems use query-based access while warehouses may prefer access to the underlying database--the essence of this challenge remains the same. Thus, …

Significant changes in materials properties of siloxane based polymers can be obtained by the addition of inorganic fillers. In silica-filled polydimethylsiloxane (PDMS) based composites the mechanism of this reinforcing behavior is presumably hydrogen bonding between surface hydroxyls and backbone siloxane species. We have chosen to investigate in detail the effect of chemisorbed and physisorbed water on the interfacial structure and dynamics in silica-filled PDMS based composites. Toward this end, we have combined molecular dynamics simulations and experimental studies employing DMA and Nh4R analysis. Our results suggest that the polymer-silica contact distance and the mobility of interfacial polymer chains significantly decreased as the hydration level at the interface was reduced. The reduced mobility of the PDMS chains in the interfacial domain reduced the overall, bulk, motional properties of the polymer, thus causing an effective ''stiffening'' of the polymer matrix. The role of the long-ranged Coulombic interactions on the structural features and chain dynamics of the polymer were also examined. Both are found to be strongly influenced by the electrostatic interactions as identified by the bond orientation time correlation function and local density distribution functions. These results have important implications for the design of nanocomposite silica-siloxane materials.

We have been performing basic materials science research on materials for anodes and cathodes in electrochemical cells. The work is a mix of electrochemical measurements and analysis of the materials by transmission electron microscopy and x-ray diffractometry. At present, our experimental work involves only materials for Li storage, but we have been finishing papers from our previous work on hydrogen-storage materials.

This report discusses the problems of release of items from facilities and installations where radiation-based activities have been carried out. Several situations are reviewed and their release problems are discussed in detail. Particular attention is devoted to the assessment of the activity of the items to be released. A correct assessment of the activity will help the decision about the final use of the items removed from the radiation-related facility, either re-use, entering the public market, recycling, disposal and storage under different procedures. Even the final destination of the building which hosted the facility needs to be decided on the basis of an accurate assessment of the residual activity. The assessment of the activity, besides being fundamental in guaranteeing a safe approach to the procedures related to the release may result in a substantial profit. This is the case of items whose level of activity is so low that they can be put on the public market, reused or recycled for final product subject to very stringent radiation safety requirements. It will be shown that detector techniques play a fundamental role in the release process. In particular, the low-level counting techniques are fundamental in establishing whether or not the unrestrained …

Airborne hazardous plumes inadvertently released during nuclear/chemical/biological incidents are mostly of unknown composition and concentration until measurements are taken of post-accident ground concentrations from plume-ground deposition of constituents. Unfortunately, measurements often are days post-incident and rely on hazardous manned air-vehicle measurements. Before this happens, computational plume migration models are the only source of information on the plume characteristics, constituents, concentrations, directions of travel, ground deposition, etc. A mobile ''lighter than air'' (LTA) system is being developed at Oak Ridge National Laboratory that will be part of the first response in emergency conditions. These interactive and remote unmanned air vehicles will carry light-weight detectors and weather instrumentation to measure the conditions during and after plume release. This requires a cooperative computationally organized, GPS-controlled set of LTA's that self-coordinate around the objectives in an emergency situation in restricted time frames. A critical step before an optimum and cost-effective field sampling and monitoring program proceeds is the collection of data that provides statistically significant information, collected in a reliable and expeditious manner. Efficient aerial arrangements of the detectors taking the data (for active airborne release conditions) are necessary for plume identification, computational 3-dimensional reconstruction, and source distribution functions. This report describes the application …