Pore compressibility in rocks (open access)

Pore compressibility in rocks

The unjacketed core compressibility in a porous rock is the change in pore volume due to change in pore pressure for constant differential pressure. This parameter affects how the saturated bulk modulus of a rock is related to the drained frame modulus and the pore fluid compressibility. Recent measurements of poroelastic constants and effective medium theories are used to estimate how the pore compressibility depends on effective stress and how uncertainty in the pore compressibility affects uncertainty in Gassmann' equation estimates of the saturated bulk modulus. Results for Berea sandstone and for models of sand-clay mixtures show that the estimate of the change in the saturated bulk modulus due to substitution of different fluids in the rock may differ in size by a factor of two or more if the pore compressibility is approximately equal to the fluid compressibility instead of the grain compressibility. In general, the order of magnitude and sign of the pore compressibility cannot be determined from solid and fluid compressibility information alone.
Date: June 5, 1998
Creator: Berge, P A
Object Type: Article
System: The UNT Digital Library
The Argonne boundary layer experiments facility : using minisodars to complement a wind profiler network. (open access)

The Argonne boundary layer experiments facility : using minisodars to complement a wind profiler network.

The Argonne Boundary Layer Experiments (ABLE) facility, located in south central Kansas, east of Wichita, is devoted primarily to investigations of and within the planetary boundary layer (PBL), including the dynamics of the mixed layer during both day and night; effects of varying land use and land form; the interactive role of precipitation, runoff, and soil moisture; storm development; and energy budgets on scales of 10 to 100 km. Located entirely within the Walnut River watershed, ABLE provides intense measurements within the northeast quadrant (Fig. 1) of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) of the Atmospheric Radiation Measurement (ARM) Program (Stokes and Schwarz, 1994). By combining the continuous measurements of ABLE with ancillary continuous measurements of, for example, the ARM and the Global Energy Water cycle Experiment (GEWEX) (Kinster and Shukla, 1990) programs, ABLE provides a platform within which shorter, more intensive studies, such as those conducted by the Cooperative Atmosphere-Surface Exchange Studies (CASES) Program, can realize the full benefit of a wide variety of atmospheric measurements on many scales; this allows the study of hypothesized features of PBL development and dynamics, including frontal dynamics, nocturnal boundary development and breakdown, urban heat island effects, precipitation enhancement, …
Date: June 5, 1998
Creator: Coulter, R. L.
Object Type: Article
System: The UNT Digital Library
Federal Emergency Management Information System (FEMIS) Bill of Materials (BOM) for FEMIS version 1.4.5 (open access)

Federal Emergency Management Information System (FEMIS) Bill of Materials (BOM) for FEMIS version 1.4.5

This document describes the hardware and software required for the Federal Emergency Management Information System version 1.4.5 (FEMIS v1.4.5). The FEMIS system is designed for a single Chemical Stockpile Emergency Preparedness Program (CSEPP) site that has multiple Emergency Operations Centers (EOCs). Each EOC has personal computers (PCs) that emergency planners and operations personnel use to do their jobs. These PCs are connected via a local area network (LAN) to servers that provide EOC-wide services. Each EOC is interconnected to other EOCs via a Wide Area Network (WAN). A UNIX server provides a platform to support the Oracle relational database management system (RDBMS) distributed by Pacific Northwest National Laboratory (PNNL), ARC/INFO geographic information system (GIS) capabilities (optional), basic file management services, the evacuation model (ESIM), the data exchange interface (DEI), and the notification service. FEMIS is a client/server system where much of the application software is located in the client PC. This client software includes the FEMIS application, government furnished dispersion and evacuation models, and Commercial-Off-The-Shelf (COTS) software applications, including the ArcView GIS and Microsoft Project (electronic planning). Several configurations are possible at a CSEPP site. In this document, a site is understood to include several installations of FEMIS, including the …
Date: June 5, 1998
Creator: Fangman, P.M.; Gerhardstein, L.H. & Homer, B.J.
Object Type: Report
System: The UNT Digital Library
Spatial filter lens design for the main laser of the National Ignition Facility (open access)

Spatial filter lens design for the main laser of the National Ignition Facility

The National Ignition Facility (NIF), being designed and constructed at Lawrence Livermore National Laboratory (LLNL), comprises 192 laser beams The lasing medium is neodymium in phosphate glass with a fundamental frequency (1{omega}) of 1 053{micro}m Sum frequency generation in a pair of conversion crystals (KDP/KD*P) will produce 1 8 megajoules of the third harmonic light (3{omega} or {lambda}=351{micro}m) at the target The purpose of this paper is to provide the lens design community with the current lens design details of the large optics in the Main Laser This paper describes the lens design configuration and design considerations of the Main Laser The Main Laser is 123 meters long and includes two spatial filters one 13 5 meters and one 60 meters These spatial filters perform crucial beam filtering and relaying functions We shall describe the significant lens design aspects of these spatial filter lenses which allow them to successfully deliver the appropriate beam characteristic onto the target For an overview of NIF please see ``Optical system design of the National Ignition Facility,`` by R Edward English. et al also found in this volume.
Date: June 5, 1998
Creator: Korniski, R. J., Optics 1 Inc, Westlake Village, CA
Object Type: Article
System: The UNT Digital Library
Reduction of B-Integral Accumulation in Lasers (open access)

Reduction of B-Integral Accumulation in Lasers

A pulsed laser is provided wherein the B-integral accumulated in the laser pulse is reduced using a semiconductor wafer. A laser pulse is generated by a laser pulse source. The laser pulse passes through a semiconductor wafer that has a negative nonlinear index of refraction. Thus, the laser pulse accumulates a negative B-integral. The laser pulse is then fed into a laser amplification medium, which has a positive nonlinear index of refraction. The laser pulse may make a plurality of passes through the laser amplification medium and accumulate a positive B-integral during a positive non-linear phase change. The semiconductor and laser pulse wavelength are chosen such that the negative B-integral accumulated in the semiconductor wafer substantially cancels the positive B-integral accumulated in the laser amplification medium. There may be additional accumulation of positive B-integral if the laser pulse passes through additional optical mediums such as a lens or glass plates. Thus , the effects of self-phase modulation in the laser pulse are substantially reduced.
Date: June 5, 1998
Creator: Meyerhofer, David D. & Konoplev, Oleg A.
Object Type: Patent
System: The UNT Digital Library
Removal of bird contamination in wind profiler signal spectra. (open access)

Removal of bird contamination in wind profiler signal spectra.

The problem of bird interference with radar performance is as old as radar itself; however, the problem specific to wind profiler operation has not drawn the attention of researchers until the last 5 or 6 years. Since then, the problem has been addressed in many publications and several ways to solve it have been indicated. Recent advances in radar hardware and software made the last generation of profilers much more immune to bird contamination. However, many older profilers are still in use; errors in averaged (hourly) winds due to bird interference may be as high as 15 m/s. The objective of the present study is to develop a practical method to derive mean winds from averaged spectral data of a 915-MHz wind profiler under the condition of bird contamination.
Date: June 5, 1998
Creator: Pekour, M. S.
Object Type: Article
System: The UNT Digital Library