Using an Ersatz Thermosiphon Loop to Model Natural Convection Flows Inside a Shallow Enclosure (open access)

Using an Ersatz Thermosiphon Loop to Model Natural Convection Flows Inside a Shallow Enclosure

Natural convection loops (NCL) can occur when extracting energy from thermal storage with immersed heat exchangers. To assist in heat exchanger design and annual performance simulations of such systems, this paper proposes modeling an NCL with a comparatively simple ''ersatz'' thermosiphon loop (ETL). In an actual thermosiphon loop, fluid in channels or pipes flows in a closed loop, driven by a net buoyancy head which is equal to the total pressure drop. In the proposed approach, ersatz flow channels corresponding to the actual NCL flow are first defined, based upon experiment, numerical solution, or other information. The heat transfer and friction coefficients in the simplified ETL model must then be adjusted to fit these known data. The test case analyzed here is a horizontal shallow enclosure with temperature boundary conditions at both ends. A numerical solution is used to calibrate the ETL, and an analytical solution is used to extrapolate to other conditions for testing the ETL mo del predictions. It is shown that over two orders of magnitude variation in heat transfer, the calibrated ETL model predicts the heat transfer to 8% RMSD.
Date: February 20, 2001
Creator: Burch, J.D. & Gawlik, K.M.
Object Type: Article
System: The UNT Digital Library
Determination of Importance Evaluation for Exploratory Studies Facility (ESF) Subsurface Testing Activities (open access)

Determination of Importance Evaluation for Exploratory Studies Facility (ESF) Subsurface Testing Activities

This Determination of Importance Evaluation (DIE) applies to the Subsurface Exploratory Studies Facility (ESF), encompassing the Topopah Spring (TS) Loop from Station 0+00 meters (m) at the North Portal to breakthrough at the South Portal (approximately 78+77 m), and ancillary test and operation support areas including the Enhanced Characterization of the Repository Block (ECRB) Cross Drift. This evaluation applies specifically to site characterization testing activities ongoing and planned in the Subsurface ESF. ESF site characterization activities are being performed to obtain the information necessary to determine whether the Yucca Mountain Site is suitable as a geologic repository for spent nuclear fuel and high-level radioactive waste. A more detailed description of these testing activities is provided in Section 6 of this DIE. Generally, the construction and operation of excavations associated with these testing activities are evaluated in the DIE for the Subsurface ESF (CRWMS M&O 1999a) and the DIE for the ESF ECRB Cross Drift (CRWMS M&O 2000a). The scope of this DIE also entails the proposed Unsaturated Zone (UZ) Transport Test at Busted Butte. Although, not a part of the TS Loop or ECRB Cross Drift, the associated testing activities are Subsurface testing activities. Busted Butte is located to the …
Date: February 20, 2001
Creator: Byrne, C.J.
Object Type: Report
System: The UNT Digital Library
Nonlinear peculiar-velocity analysis and PCA (open access)

Nonlinear peculiar-velocity analysis and PCA

We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain {approximately}35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be of the flat {Lambda}CDM model (h = 0:65, n = 1) with only {Omega}{sub m} free. Since the likelihood is driven by the nonlinear regime, we break the power spectrum at k{sub b} {approximately} 0.2 (h{sup {minus}1} Mpc){sup {minus}1} and fit a two-parameter power-law at k > k{sub b} . This allows for an unbiased fit in the linear regime. Tests using improved mock catalogs demonstrate a reduced bias and a better fit. We find for the Mark III and SFI data {Omega}{sub m} = 0.35 {+-} 0.09 with {sigma}{sub 8}{Omega}P{sub m}{sup 0.6} = 0.55 {+-} 0.10 (90% errors). When allowing deviations from {Lambda}CDM, we find an indication for a wiggle in the power spectrum in the form of an excess near k {approximately} 0.05 and a deficiency at k {approximately} 0.1 (h{sup {minus}1} Mpc){sup {minus}1}--a cold flow which may be related to a feature indicated from redshift surveys and the second peak in the CMB anisotropy. A {chi}{sup 2} test …
Date: February 20, 2001
Creator: Dekel, A.
Object Type: Article
System: The UNT Digital Library
Ground-Coupled Heat and Moisture Transfer from Buildings; Part1: Analysis and Modeling (preprint) (open access)

Ground-Coupled Heat and Moisture Transfer from Buildings; Part1: Analysis and Modeling (preprint)

Ground-heat transfer is tightly coupled with soil-moisture transfer. The coupling is threefold: heat is transferred by thermal conduction and by moisture transfer; the thermal properties of soil are strong functions of the moisture content; and moisture phase change includes latent heat effects and changes in thermal and hydraulic properties. A heat and moisture transfer model was developed to study the ground-coupled heat and moisture transfer from buildings. The model also includes detailed considerations of the atmospheric boundary conditions, including precipitation. Solutions for the soil temperature distribution are obtained using a finite element procedure. The model compared well with the seasonal variation of measured ground temperatures.
Date: February 20, 2001
Creator: Deru, M. P. & Kirkpatrick, A. T.
Object Type: Article
System: The UNT Digital Library
Simulating Intense Ion Beams for Inertial Fusion Energy (open access)

Simulating Intense Ion Beams for Inertial Fusion Energy

The Heavy Ion Fusion (HIF) program's goal is the development of the body of knowledge needed for Inertial Fusion Energy (IFE) to realize its promise. The intense ion beams that will drive HIF targets are nonneutral plasmas and exhibit collective, nonlinear dynamics which must be understood using the kinetic models of plasma physics. This beam physics is both rich and subtle: a wide range in spatial and temporal scales is involved, and effects associated with both instabilities and non-ideal processes must be understood. Ion beams have a ''long memory'', and initialization of a beam at mid-system with an idealized particle distribution introduces uncertainties; thus, it will be crucial to develop, and to extensively use, an integrated and detailed ''source-to-target'' HIF beam simulation capability. We begin with an overview of major issues.
Date: February 20, 2001
Creator: Friedman, A
Object Type: Article
System: The UNT Digital Library
Simulating Intense Ion Beams for Inertial Fusion Energy (open access)

Simulating Intense Ion Beams for Inertial Fusion Energy

The Heavy Ion Fusion (HIF) program's goal is the development of the body of knowledge needed for Inertial Fusion Energy (IFE) to realize its promise. The intense ion beams that will drive HIF targets are rzonneutral plasmas and exhibit collective, nonlinear dynamics which must be understood using the kinetic models of plasma physics. This beam physics is both rich and subtle: a wide range in spatial and temporal scales is involved, and effects associated with both instabilities and non-ideal processes must be understood. Ion beams have a ''long memory,'' and initialization of a beam at mid-system with an idealized particle distribution introduces uncertainties; thus, it will be crucial to develop, and to extensively use, an integrated and detailed ''source-to-target'' HIF beam simulation capability. We begin with an overview of major issues.
Date: February 20, 2001
Creator: Friedman, A.
Object Type: Article
System: The UNT Digital Library
A/M Area DNAPL Characterization Report for Cores Collected in FY97 and 1Q98 and 2Q98 (open access)

A/M Area DNAPL Characterization Report for Cores Collected in FY97 and 1Q98 and 2Q98

Drilling activities were conducted in FY97 and FY98 in the A/M Area to further identify areas of pure phase DNAPL below the water table. The purpose of the work was to further understand the subsurface contaminant distribution and to identify locations below the water table where aggressive DNAPL remediation technologies should be pursued.
Date: February 20, 2001
Creator: Jerome, K. M.
Object Type: Report
System: The UNT Digital Library
Implications of Export/Import Reporting Requirements in the United States - International Atomic Energy Agency Safeguards Additional Protocol (open access)

Implications of Export/Import Reporting Requirements in the United States - International Atomic Energy Agency Safeguards Additional Protocol

The United States has signed but not ratified the US/IAEA Safeguards Additional Protocol. If ratified, the Additional Protocol will require the US to report to the IAEA certain nuclear-related exports and imports to the IAEA. This document identifies and assesses the issues associated with the US making those reports. For example, some regulatory changes appear to be necessary. The document also attempts to predict the impact on the DOE Complex by assessing the historical flow of exports and imports that would be reportable if the Additional Protocol were in force.
Date: February 20, 2001
Creator: Killinger, Mark H.; Benjamin, Eugene L. & McNair, Gary W.
Object Type: Report
System: The UNT Digital Library
Implications of Export/Import Reporting Requirements in the United States - International Atomic Energy Agency Safeguards Additional Protocol (open access)

Implications of Export/Import Reporting Requirements in the United States - International Atomic Energy Agency Safeguards Additional Protocol

The US has signed but not ratified the US/IAEA Safeguards Additional Protocol. If ratified, the Additional Protocol will require the US to report to the IAEA certain nuclear-related exports and imports to the IAEA. This document identifies and assesses the issues associated with the US making those reports. For example, some regulatory changes appear to be necessary. The document also attempts to predict the impact on the DOE Complex by assessing the historical flow of exports and imports that would be reportable if the Additional Protocol were in force.
Date: February 20, 2001
Creator: Killinger, Mark H; Benjamin, Eugene L & McNair, Gary W
Object Type: Report
System: The UNT Digital Library
Dislocation dynamics: simulation of plastic flow of bcc metals (open access)

Dislocation dynamics: simulation of plastic flow of bcc metals

This is the final report for the LDRD strategic initiative entitled ''Dislocation Dynamic: Simulation of Plastic Flow of bcc Metals'' (tracking code: 00-SI-011). This report is comprised of 6 individual sections. The first is an executive summary of the project and describes the overall project goal, which is to establish an experimentally validated 3D dislocation dynamics simulation. This first section also gives some information of LLNL's multi-scale modeling efforts associated with the plasticity of bcc metals, and the role of this LDRD project in the multiscale modeling program. The last five sections of this report are journal articles that were produced during the course of the FY-2000 efforts.
Date: February 20, 2001
Creator: Lassila, D H
Object Type: Report
System: The UNT Digital Library
Supersymmetric radiative corrections at large tan {beta} (open access)

Supersymmetric radiative corrections at large tan {beta}

In the minimal supersymmetric extension of the Standard Model (MSSM), fermion masses and Yukawa couplings receive radiative corrections at one loop from diagrams involving the supersymmetric particles. The corrections to the relation between down-type fermion masses and Yukawa couplings are enhanced by tan {beta}, which makes them potentially very significant at large tan {beta}. These corrections affect a wide range of processes in the MSSM, including neutral and charged Higgs phenomenology, rare B meson decays, and renormalization of the CKM matrix. We give a pedagogical review of the sources and phenomenological effects of these corrections.
Date: February 20, 2001
Creator: Logan, H.E.
Object Type: Article
System: The UNT Digital Library
Farm batch system and Fermi inter-process communication and synchronization toolkit (open access)

Farm batch system and Fermi inter-process communication and synchronization toolkit

Farms Batch System (FBS) was developed as a batch process management system for off-line Run II data processing at Fermilab. FBS will manage PC farms composed of up to 250 nodes and scalable to 1000 nodes with disk capacity of up to several TB. FBS allows users to start arrays of parallel processes on multiple computers. It uses a simplified resource counting method load balancing. FBS has been successfully used for more than a year at Fermilab by fixed target experiments and will be used for collider experiment off-line data processing. Fermi Inter-Process Communication toolkit (FIPC) was designed as a supplement product for FBS that helps establish synchronization and communication between processes running in a distributed batch environment. However, FIPC is an independent package, and can be used with other batch systems, as well as in a non-batch environment. FIPC provides users with a variety of global distributed objects such as semaphores, queues and string variables. Other types of objects can be easily added to FIPC. FIPC has been running on several PC farms at Fermilab for half a year and is going to be used by CDF for off-line data processing.
Date: February 20, 2001
Creator: Mandrichenko, I.V.
Object Type: Article
System: The UNT Digital Library
Heavy-Section Steel Irradiation (HSSI) Program (W6953) Monthly Letter Status Report - January 2001 - ORNL/HSSI (6953) MLSR-2001/4 (open access)

Heavy-Section Steel Irradiation (HSSI) Program (W6953) Monthly Letter Status Report - January 2001 - ORNL/HSSI (6953) MLSR-2001/4

This report is issued monthly by the staff of the Heavy-Section Steel Irradiation (HSSI) Program (JCN:W6953) to provide the Nuclear Regulatory Commission (NRC) staff with summaries of technical highlights, important issues, and financial and milestone status within the program. This report gives information on several topics corresponding to events during the reporting month: (1) overall project objective, (2) technical activities, (3) meetings and trips, (4) publications and presentations, (5) property acquired, (6) problem areas, and (7) plans for the next reporting period. Next the report gives a breakdown of overall program costs as well as cost summaries and earned-value-based estimates for performance for the total program and for each of the eight program tasks. The seven tasks correspond to the 189, dated March 23, 1998, and modified by the inclusion of the former ''Embrittlement Data Base and Dosimetry Evaluation'' Program, JCN 6164 in March, 1999. The final part of the report provides financial status for all tasks and status reports for selected milestones within each task. The task milestones address the period from October 2000 to March 2003, while the individual task budgets address the period from October 2000 to February 2001. Beginning in October, 1992, the monthly business calendar …
Date: February 20, 2001
Creator: Rosseel, T. M.
Object Type: Report
System: The UNT Digital Library