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Mars ascent propulsion options for small sample return vehicles (open access)

Mars ascent propulsion options for small sample return vehicles

None
Date: May 12, 1997
Creator: Whitehead, J. C., LLNL
Object Type: Article
System: The UNT Digital Library
Gas core nuclear rocket feasibility project (open access)

Gas core nuclear rocket feasibility project

The next giant leap for mankind will be the human exploration of Mars. Almost certainly within the next thirty years, a human crew will brave the isolation, the radiation, and the lack of gravity to walk on and explore the Red planet. However, because the mission distances and duration will be hundreds of times greater than the lunar missions, a human crew will face much greater obstacles and a higher risk than those experienced during the Apollo program. A single solution to many of these obstacles is to dramatically decrease the mission duration by developing a high performance propulsion system. The gas core nuclear rocket (GCNR) has the potential to be such a system. The gas core concept relies on the use of fluid dynamic forces to create and maintain a vortex. The vortex is composed of a fissile material which will achieve criticality and produce high power levels. By radiatively coupling to the surrounding fluids, extremely high temperatures in the propellant and, thus, high specific impulses can be generated. The ship velocities enabled by such performance may allow a 9 month round trip, manned Mars mission to be considered. Alternatively, one might consider slightly longer missions in ships that …
Date: September 1997
Creator: Howe, S. D.; DeVolder, B.; Thode, L. & Zerkle, D.
Object Type: Article
System: The UNT Digital Library
Modeling human risk: Cell & molecular biology in context (open access)

Modeling human risk: Cell & molecular biology in context

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with …
Date: June 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Final Report: Experimental Investigation of Nonlinear Plasma Wake-Fields (open access)

Final Report: Experimental Investigation of Nonlinear Plasma Wake-Fields

We discuss the exploration of the newly proposed blowout regime of the plasma wakefield accelerator and advanced photoinjector technology for linear collider applications. The plasma wakefield experiment at ANL produced several ground-breaking results in the physics of the blowout regime. The photoinjector R and D effort produced breakthroughs in theoretical, computational, and experimental methods in high brightness beam physics. Results have been published.
Date: October 31, 1997
Creator: Rosenzweig, J.
Object Type: Report
System: The UNT Digital Library
The Europa Ocean Discovery mission (open access)

The Europa Ocean Discovery mission

Since it was first proposed that tidal heating of Europa by Jupiter might lead to liquid water oceans below Europa`s ice cover, there has been speculation over the possible exobiological implications of such an ocean. Liquid water is the essential ingredient for life as it is known, and the existence of a second water ocean in the Solar System would be of paramount importance for seeking the origin and existence of life beyond Earth. The authors present here a Discovery-class mission concept (Europa Ocean Discovery) to determine the existence of a liquid water ocean on Europa and to characterize Europa`s surface structure. The technical goal of the Europa Ocean Discovery mission is to study Europa with an orbiting spacecraft. This goal is challenging but entirely feasible within the Discovery envelope. There are four key challenges: entering Europan orbit, generating power, surviving long enough in the radiation environment to return valuable science, and complete the mission within the Discovery program`s launch vehicle and budget constraints. The authors will present here a viable mission that meets these challenges.
Date: June 1, 1997
Creator: Edwards, B.C.; Chyba, C.F. & Abshire, J.B.
Object Type: Article
System: The UNT Digital Library
Oil and Gas R&D Programs (open access)

Oil and Gas R&D Programs

This publication describes the major components of the research and development programs of the Department of Energy`s Office of Natural Gas and Petroleum Technology. These programs are commonly referred to collectively as the `Oil and Gas Program.` This document provides customers with a single source of information describing the details of the individual technology program components. This document reflects the results of a planning cycle that began in early 1996 with the development of a scenario analysis for the programs, followed by the development of the coordinated strategic plan. The technology program plans, which are the most recent products of the planning cycle, expand on the program descriptions presented in the coordinated strategic plan, and represent an initial effort to coordinate the Oil and Gas Program exploration and production programs and budgets. Each technology program plan includes a `roadmap` that summarizes the progress of the program to the present and indicates its future direction. The roadmaps describe the program drivers, vision, mission, strategies, and measures of success. Both the individual technology program plans and the strategic plan are dynamic and are intended to be updated regularly.
Date: March 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
US crude oil, natural gas, and natural gas liquids reserves 1996 annual report (open access)

US crude oil, natural gas, and natural gas liquids reserves 1996 annual report

The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1996, as well as production volumes for the US and selected States and State subdivisions for the year 1996. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil …
Date: December 1, 1997
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Shallow 3-D vertical seismic profiling around a contaminant withdrawal well on the Lawrence Livermore National Laboratory Site (open access)

Shallow 3-D vertical seismic profiling around a contaminant withdrawal well on the Lawrence Livermore National Laboratory Site

One of the major problems associated with ground water contaminant remediation is well placement. Optimal-placement of wells requires an accurate knowledge of geologic structure and stratigraphy in the near surface sediments and rock (0 to 100 m). Without the development of remote imaging provided by geophysical techniques, the required spacing between treatment wells may be less than 2 m in order to be confident that all contaminant reservoirs had been remediated. One method for characterizing geologic structure and stratigraphy in the near surface is vertical seismic profiling (VSP), a technique often used on deep exploration wells to calibrate surface seismic reflection data. For near-surface applications, VSP data can be acquired efficiently using an array of hydrophones lowered into a fluid-filled borehole (Milligan et al, 1997). In this paper we discuss the acquisition and processing of a 3-D VSP collected at a shallow remediation site located on the grounds of the Lawrence Livermore National Laboratory (LLNL) near Livermore, California. The site was used by the United States Navy as an air training base. At this time, initial releases of hazardous materials to the environment occurred in the form of solvents [volatile organic compounds (VOCs)] that were used for the cleaning of …
Date: January 30, 1997
Creator: Rector, J.; Bainer, R.; Milligan, P. & Tong, C.
Object Type: Report
System: The UNT Digital Library
University Press (Beaumont, Tex.), Vol. 74, No. 23, Ed. 1 Wednesday, November 19, 1997 (open access)

University Press (Beaumont, Tex.), Vol. 74, No. 23, Ed. 1 Wednesday, November 19, 1997

Semiweekly newspaper from Lamar University in Beaumont, Texas that includes local, national, and campus news along with advertising.
Date: November 19, 1997
Creator: Andris, Tonya
Object Type: Newspaper
System: The Portal to Texas History
The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 14, Ed. 1 Thursday, July 10, 1997 (open access)

The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 14, Ed. 1 Thursday, July 10, 1997

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date: July 10, 1997
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Wynnewood Gazette (Wynnewood, Okla.), Vol. 94, No. 40, Ed. 1 Thursday, January 9, 1997 (open access)

The Wynnewood Gazette (Wynnewood, Okla.), Vol. 94, No. 40, Ed. 1 Thursday, January 9, 1997

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date: January 9, 1997
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History
Robust tracking with spatio-velocity snakes: Kalman filtering approach (open access)

Robust tracking with spatio-velocity snakes: Kalman filtering approach

Using results from robust Kalman filtering, the author presents a new Kalman filter-based snake model for tracking of nonrigid objects in combined spatio-velocity space. The proposed model is the stochastic version of the velocity snake, an active contour model for combined tracking of position and velocity of nonrigid boundaries. The proposed model uses image gradient and optical flow measurements along the contour as system measurements. An optical-flow based measurement error is used to detect and reject image measurements which correspond to image clutter or to other objects. The method was applied to object tracking of both rigid and nonrigid objects, resulting in good tracking results and robustness to image clutter, occlusions and numerical noise.
Date: June 1, 1997
Creator: Peterfreund, N.
Object Type: Report
System: The UNT Digital Library
The Chickasha Star (Chickasha, Okla.), Vol. 95, No. 163, Ed. 1 Saturday, January 4, 1997 (open access)

The Chickasha Star (Chickasha, Okla.), Vol. 95, No. 163, Ed. 1 Saturday, January 4, 1997

Newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: January 4, 1997
Creator: Settle, David
Object Type: Newspaper
System: The Gateway to Oklahoma History
The velocity snake: Deformable contour for tracking in spatio-velocity space (open access)

The velocity snake: Deformable contour for tracking in spatio-velocity space

The author presents a new active contour model for boundary tracking and position prediction of nonrigid objects, which results from applying a velocity control to the class of elastodynamical contour models, known as snakes. The proposed control term minimizes an energy dissipation function which measures the difference between the contour velocity and the apparent velocity of the image. Treating the image video-sequence as continuous measurements along time, it is shown that the proposed control results in an unbiased tracking. This is in contrast to the original snake model which is proven to be biased due to the image (object) velocity, thus resulting in high sensitivity to image clutter. The motion estimation further allows for position prediction of nonrigid boundaries. Based on the proposed control approach, the author proposes a new class of real time tracking contours, varying from models with batch-mode control estimation to models with real time adaptive controllers.
Date: June 1, 1997
Creator: Peterfreund, N.
Object Type: Report
System: The UNT Digital Library
The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 25, Ed. 1 Thursday, September 25, 1997 (open access)

The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 25, Ed. 1 Thursday, September 25, 1997

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date: September 25, 1997
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 81, No. 186, Ed. 1 Friday, July 4, 1997 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 81, No. 186, Ed. 1 Friday, July 4, 1997

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: July 4, 1997
Creator: Harden, Andrea
Object Type: Newspaper
System: The Gateway to Oklahoma History
Chickasha Daily Express (Chickasha, Okla.), Vol. 107, No. 123, Ed. 1 Monday, August 18, 1997 (open access)

Chickasha Daily Express (Chickasha, Okla.), Vol. 107, No. 123, Ed. 1 Monday, August 18, 1997

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: August 18, 1997
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
A comparison of three redundancy resolution methods (open access)

A comparison of three redundancy resolution methods

The report performs an analytical comparison of three redundancy resolution methods developed by researchers at the Oak Ridge National Laboratory that obtain solutions for the joint velocities for a redundant manipulator based on its kinematic velocity model with an (m x n) Jacobian matrix of full rank m(< n): (i) the Input Relegation Control (IRC) Method; the Belmans and Culioli (B and C) method; and an extension of the B and C method termed Full Space Parameterization (FSP). The report is organized as follows: the three methods are reviewed in section 2. The comparison of the IRC and B and C methods is presented in section 3. The IRC and FSP methods are compared in section 4. The unification of the B and C and FSP null space parameterizations and joint velocity solution methods is discussed in section 5. Constraint free representations of the B and C and FSP joint velocity solutions are derived in terms of the IRC basis and compared to IRC in Appendix A. A summary and conclusion are provided in the final section.
Date: October 1, 1997
Creator: Unseren, M.A. & Reister, D.B.
Object Type: Report
System: The UNT Digital Library
The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 23, Ed. 1 Thursday, September 11, 1997 (open access)

The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 23, Ed. 1 Thursday, September 11, 1997

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date: September 11, 1997
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History
An improved method for calculating self-motion coordinates for redundant manipulators (open access)

An improved method for calculating self-motion coordinates for redundant manipulators

For a redundant manipulator, the objective of redundancy resolution is to follow a specified path in Cartesian space and simultaneously perform another task (for example, maximize an objective function or avoid obstacles) at every point along the path. The conventional methods have several drawbacks: a new function must be defined for each task, the extended Jacobian can be singular, closed cycles in Cartesian space may not yield closed cycles in joint space, and the objective is point-wise redundancy resolution (to determine a single point in joint space for each point in Cartesian space). The author divides the redundancy resolution problem into two parts: (1) calculate self-motion coordinates for all possible positions of a manipulator at each point along a Cartesian path and (2) determination of optimal self-motion coordinates that maximize an objective function along the path. This paper will discuss the first part of the problem. The path-wise approach overcomes all of the drawbacks of conventional redundancy resolution methods: no need to define a new function for each task, extended Jacobian cannot be singular, and closed cycles in extended Cartesian space will yield closed cycles in joint space.
Date: April 1, 1997
Creator: Reister, D.B.
Object Type: Report
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 82, No. 247, Ed. 1 Tuesday, July 1, 1997 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 82, No. 247, Ed. 1 Tuesday, July 1, 1997

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: July 1, 1997
Creator: Diehl, Don
Object Type: Newspaper
System: The Gateway to Oklahoma History
A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object (open access)

A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object

The report reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restricts the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and …
Date: September 1, 1997
Creator: Unseren, M.A.
Object Type: Report
System: The UNT Digital Library
Businesslike Government: Lessons Learned From America's Best Companies (open access)

Businesslike Government: Lessons Learned From America's Best Companies

Book containing recommendations and lessons learned from many of America's best companies on how the federal government can improve its efficiency and customer focus.
Date: October 1997
Creator: Gore, Al, 1948-
Object Type: Book
System: The UNT Digital Library
The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 37, Ed. 1 Thursday, December 18, 1997 (open access)

The Wynnewood Gazette (Wynnewood, Okla.), Vol. 95, No. 37, Ed. 1 Thursday, December 18, 1997

Weekly newspaper from Wynnewood, Oklahoma that includes local, state, and national news along with advertising.
Date: December 18, 1997
Creator: unknown
Object Type: Newspaper
System: The Gateway to Oklahoma History