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Chemical Safety Alert: Anhydrous Ammonia Theft

Description: This publication of Alert presents the Environmental Protection Agency's analysis of anhydrous ammonia as used for agricultural fertilizer and industrial refrigerant.
Date: March 2000
Creator: United States. Environmental Protection Agency. Office of Solid Waste and Emergency Response.
Partner: UNT Libraries Government Documents Department


Description: The Energy Information Administration's (EIA's) National Energy Modeling System (NEMS) Freight Truck Stock Adjustment Model (FTSAM) was created in 1995 relying heavily on input data from the 1992 Economic Census, Truck Inventory and Use Survey (TIUS). The FTSAM is part of the NEMS Transportation Sector Model, which provides baseline energy projections and analyzes the impacts of various technology scenarios on consumption, efficiency, and carbon emissions. The base data for the FTSAM can be updated every five years as new Economic Census information is released. Because of expertise in using the TIUS database, Oak Ridge National Laboratory (ORNL) was asked to assist the EIA when the new Economic Census data were available. ORNL provided the necessary base data from the 1997 Vehicle Inventory and Use Survey (VIUS) and other sources to update the FTSAM. The next Economic Census will be in the year 2002. When those data become available, the EIA will again want to update the FTSAM using the VIUS. This report, which details the methodology of estimating and extracting data from the 1997 VIUS Microdata File, should be used as a guide for generating the data from the next VIUS so that the new data will be as compatible as possible with the data in the model.
Date: November 16, 2000
Creator: Davis, S.C.
Partner: UNT Libraries Government Documents Department

Polymethylsilsesquioxanes through base-catalyzed redistribution of oligomethylhydridosiloxanes

Description: There has been an increasing amount of interest in silsesquioxanes and polysilsesquioxanes. They have been used as models for silica surfaces and have been shown to have great potential for several industrial applications. Typical synthesis of polysilsesquioxanes involves the hydrolysis of organotricholorosilanes and/or organotrialkoxysilanes in the presence of acid or base catalysts, usually in the presence of organic solvents.
Date: April 4, 2000
Partner: UNT Libraries Government Documents Department

A validation process for multi-phase reacting flow CFD code

Description: Computational fluid dynamic (CFD) code calculates flow properties for the analysis of a flow system. Flow properties are computed based on conservation principles and various phenomenological models. The accuracy of the computed flow properties highly depends on the validity of the models and the degree of numerical convergence. Validation of a CFD code is essential for application of an engineering system. Multiphase reacting flows are common in industrial applications and few CFD code are available. A CFD code was developed for the simulation of multiphase reacting flows. A validation process was also developed for such a CFD code. The validation was performed for several cases. Examples of industrial devices which are multiphase reacting flow systems include catalytic cracking reactors, glass melting furnaces, coal-fired combustors, and diesel engines.
Date: May 9, 2000
Creator: Chang, S. L.; Zhou, C. Q. & Petrick, M.
Partner: UNT Libraries Government Documents Department

Enrique: A case study of a gifted computer user

Description: The author has been investigating the affective and intellectual views that gifted children have about computers. These studies have used various methodological approaches in order to develop a broad perspective on the issues involved in this topic. The author has used survey instruments (Sesko, 1998) and interview techniques (Sesko, 1999) to capture both statistical and narrative data. The objective of this study is to explore in depth the interactions that one student has with the machine and its applications. The driver for this and the previous studies was the paucity of research in the area of gifted and talented children and their involvement with what has become the primary intellectual tool of the century (Turkel, 1984). The second reason is that it has been posited that the intellectual characteristics of gifted children should enable those who are interested in computers to achieve a high level of proficiency with either computer applications or programming. Further, the ability to learn things at a young age should allow gifted children who use computers to develop a large variety of computer-based activities. The author has shown evidence to support these ideas in previous work. Finally, as Hausman (1985) claims, facilities with computers should allow these children to create new activities for using computers. The author found no published research to demonstrate whether they do; but still believes the results of this case study strongly support Hausman's contentions.
Date: March 17, 2000
Creator: Sesko, S C
Partner: UNT Libraries Government Documents Department

The Fermilab computing farms in 1999

Description: The farms in 1999 changed in two major ways. First, PC's running Linux continued to expand and this allowed for the reduction of the SGI and IBM components of the farms. Second, the first large farms for CDF and D0 Run II were purchased and installed in 1999. Simultaneously, a large increment for non-Run II computing was made. The farms continue to provide large CPU resources for those experiments and calculations which benefit from this type of computing (large CPU, low I/O, dedicated resources). Farms usage will continue to increase given the demands of the user community (reflecting the scientific program) and the preparation for and beginning of Run II.
Date: May 10, 2000
Creator: al., Marina Albert et
Partner: UNT Libraries Government Documents Department

NCSL National Measurement Interlaboratory Comparison Database requirements

Description: With the recent development of an International Comparisons Database which provides worldwide access to measurement comparison data between National Measurement Institutes, there is currently renewed interest in developing a database of comparisons for calibration laboratories within a country. For many years, the National Conference of Standards Laboratories (NCSL), through the Measurement Comparison Programs Committee, has sponsored Interlaboratory Comparisons in a variety of measurement areas. This paper will discuss the need for such a National database which catalogues and maintains Interlaboratory Comparisons data. The paper will also discuss future requirements in this area.
Date: April 20, 2000
Partner: UNT Libraries Government Documents Department

Computing Farms

Description: High energy physics, nuclear physics, space sciences, and many other fields have large challenges in computing. In recent years, PCs have achieved performance comparable to the high-end UNIX workstations, at a small fraction of the price. The authors review the development and broad applications of commodity PCs as the solution to CPU needs, and look forward to the important and exciting future of large scale PC computing.
Date: April 10, 2000
Creator: Yeh, G.P.
Partner: UNT Libraries Government Documents Department

Single transverse mode selectively oxidized vertical cavity lasers

Description: Vertical cavity surface emitting lasers (VCSELs) which operate in multiple transverse optical modes have been rapidly adopted into present data communication applications which rely on multi-mode optical fiber. However, operation only in the fundamental mode is required for free space interconnects and numerous other emerging VCSEL applications. Two device design strategies for obtaining single mode lasing in VCSELs based on mode selective loss or mode selective gain are reviewed and compared. Mode discrimination is attained with the use of a thick tapered oxide aperture positioned at a longitudinal field null. Mode selective gain is achieved by defining a gain aperture within the VCSEL active region to preferentially support the fundamental mode. VCSELs which exhibit greater than 3 mW of single mode output power at 850 nm with mode suppression ratio greater than 30 dB are reported.
Date: April 26, 2000
Partner: UNT Libraries Government Documents Department

Laser beam shaping techniques

Description: Industrial, military, medical, and research and development applications of lasers frequently require a beam with a specified irradiance distribution in some plane. A common requirement is a laser profile that is uniform over some cross-section. Such applications include laser/material processing, laser material interaction studies, fiber injection systems, optical data image processing, lithography, medical applications, and military applications. Laser beam shaping techniques can be divided into three areas: apertured beams, field mappers, and multi-aperture beam integrators. An uncertainty relation exists for laser beam shaping that puts constraints on system design. In this paper the authors review the basics of laser beam shaping and present applications and limitations of various techniques.
Date: March 16, 2000
Creator: Dicky, Fred M.; Weichman, Louis S. & Shagam, Richard N.
Partner: UNT Libraries Government Documents Department

Final Report: International Symposium on Environmental Biotechnology

Description: This meeting included technical presentations of state-of-the-art research which were integrated with tutorials and workshops by practicing technologies in the broad field of environmental biotechnology. This meeting was designed to be, in every respect, truly global. Over 150 excellent abstracts from around the world were accepted. For example, presentations were heard from technical workers in Southeast Asia, Russia, China, Europe, North Africa, India, and the US. By having these selected presenters, as well as identified experienced tutors with focused workshops, all participants benefited from this interactive symposium. A number of social events further promoted informal exchange of ideas, discussions of technical problems, and exploration of new applications. This international symposium on environmental biotechnology was on the campus of Northeastern University but all Boston area universities were included and participated using designed conference Co-Chairs. This symposium, with an attendance of several hundred people, was considered a major success. Workers with experience in one area of environmental biotechnology learned from the wealth of established backgrounds of those in other areas of environmental biotechnology. To formally disseminate conference results, it was pre-arranged that all technical presentations were reviewed for formal publications.
Date: March 20, 2000
Creator: Wise, Donald L.
Partner: UNT Libraries Government Documents Department

Voice and Data Network of Convergence and the Application of Voice over IP

Description: This paper looks at emerging technologies for converging voice and data networks and telephony transport over a data network using Internet Protocols. Considered are the benefits and drivers for this convergence. The paper describes these new technologies, how they are being used, and their application to Sandia.
Date: November 1, 2000
Creator: Eldridge, J. M.
Partner: UNT Libraries Government Documents Department

Rapid Prototyping of Patterned Multifunctional Nanostructures

Description: The ability to engineer ordered arrays of objects on multiple length scales has potential for applications such as microelectronics, sensors, wave guides, and photonic lattices with tunable band gaps. Since the invention of surfactant templated mesoporous sieves in 1992, great progress has been made in controlling different mesophases in the form of powders, particles, fibers, and films. To date, although there have been several reports of patterned mesostructures, materials prepared have been limited to metal oxides with no specific functionality. For many of the envisioned applications of hierarchical materials in micro-systems, sensors, waveguides, photonics, and electronics, it is necessary to define both form and function on several length scales. In addition, the patterning strategies utilized so far require hours or even days for completion. Such slow processes are inherently difficult to implement in commercial environments. The authors present a series of new methods of producing patterns within seconds. Combining sol-gel chemistry, Evaporation-Induced Self-Assembly (EISA), and rapid prototyping techniques like pen lithography, ink-jet printing, and dip-coating on micro-contact printed substrates, they form hierarchically organized silica structures that exhibit order and function on multiple scales: on the molecular scale, functional organic moieties are positioned on pore surfaces, on the mesoscale, mono-sized pores are organized into 1-, 2-, or 3-dimensional networks, providing size-selective accessibility from the gas or liquid phase, and on the macroscale, 2-dimensional arrays and fluidic or photonic systems may be defined. These rapid patterning techniques establish for the first time a link between computer-aided design and rapid processing of self-assembled nanostructures.
Date: July 18, 2000
Partner: UNT Libraries Government Documents Department

Medical applications of nuclear physics and heavy-ion beams

Description: Isotopes and accelerators, hallmarks of nuclear physics, are finding increasingly sophisticated and effective applications in the medical field. Diagnostic and therapeutic uses of radioisotopes are now a $10B/yr business worldwide, with over 10 million procedures and patient studies performed every year. This paper will discuss the use of isotopes for these applications. In addition, beams of protons and heavy ions are being more and more widely used clinically for treatment of malignancies. To be discussed here as well will be the rationale and techniques associated with charged-particle therapy, and the progress in implementation and optimization of these technologies for clinical use.
Date: August 1, 2000
Creator: Alonso, Jose R.
Partner: UNT Libraries Government Documents Department

Optical patterning of photosensitive thin film silica mesophases

Description: Photosensitive films incorporating molecular photoacid generators compartmentalized within a silica-surfactant mesophase were prepared by an evaporation-induced self-assembly process. UV-exposure promoted localized acid-catalyzed siloxane condensation, enabling selective etching of unexposed regions, thereby serving as a resistless technique to prepare patterned mesoporous silica. The authors also demonstrated an optically-defined mesophase transformation (hexagonal {r_arrow} tetragonal) and patterning of refractive index and wetting behavior. Spatial control of structure and function on the macro- and mesoscales is of interest for sensor arrays, nano-reactors, photonic and fluidic devices, and low dielectric constant films. More importantly, it extends the capabilities of conventional lithography from spatially defining the presence or absence of film to spatial control of film structure and function.
Date: February 9, 2000
Partner: UNT Libraries Government Documents Department


Description: Inelastic x-ray scattering (IXS) provides high-pressure research with an arsenal of analytical capabilities for key measurements that were previously unattainable, and high pressure research provides IXS with numerous applications where the technique has unique advantages over other methods. High-pressure investigations can now be conducted using non-resonant IXS, resonant IXS, nuclear resonant IXS, and x-ray emission spectroscopy with energy resolutions of 100 meV to 1 eV for electronic transitions and 1 to 10 meV for phonon studies. By pressure-tuning materials over a wide range, we are able to investigate fundamental physics of electron gases, strongly correlated electron systems, high-energy electronic excitations, and phonons in energy and momentum space. The results will have a profound influence on materials applications as well as providing basic information for understanding the deep interior of the Earth and other planets.
Date: August 28, 2000
Creator: MAO, H.K.; HEMLEY, J. & KAO, C.C.
Partner: UNT Libraries Government Documents Department