Through Weld Inspection of Wrought Stainless Steel Piping Using Phased-Array Ultrasonic Probes. (open access)

Through Weld Inspection of Wrought Stainless Steel Piping Using Phased-Array Ultrasonic Probes.

A study was conducted to assess the ability of phased-array ultrasonic techniques to detect and accurately determine the size of flaws from the far-side of wrought austenitic piping welds. Far-side inspections of these welds are currently performed on a “best effort” basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, four circumferential welds in 610mm diameter, 36mm thick ASTM A-358, Grade 304 vintage austenitic stainless steel pipe were examined. The welds were fabricated with varied welding parameters; both horizontal and vertical pipe orientations were used, with air and water backing, to simulate field welding conditions. A series of saw cuts, electro-discharge machined (EDM) notches, and implanted fatigue cracks were placed into the heat affected zones of the welds. The saw cuts and notches range in depth from 7.5% to 28.4% through-wall. The implanted cracks ranged in depth from 5% through wall to 64% through wall. The welds were examined with two phased-array probes, a 2.0 MHz transmit-receive longitudinal wave array and a 2.0 MHz transmit-receive shear wave array. These examinations showed that both phased-array transducers were able to detect and accurately length-size, but not depth size, all of the notches and …
Date: August 5, 2004
Creator: Anderson, Michael T.; Cumblidge, Stephen E. & Doctor, Steven R.
Object Type: Article
System: The UNT Digital Library
Coefficient of Thermal Expansion of the Beta and Delta Polymorphs of HMX (open access)

Coefficient of Thermal Expansion of the Beta and Delta Polymorphs of HMX

Dimensional changes related to temperature cycling of the beta and delta polymorphs of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) are important for a variety of applications. The coefficient of thermal expansion (CTE) of the beta and delta phases are measured and reported in this work over a temperature range of -20 C to 215 C. In addition, dimensional changes associated with the phase transition were measured, both through the transition and back down. Initially, differential scanning calorimetry (DSC) was used to investigate back conversion of the delta phase to the beta phase polymorph. The most successful approach was first to measure the amount of the beta to delta conversion, then after a given cooling period a repeat analysis, to measure the heat consumed by a second pass through the beta to delta phase transition. In addition, TMA is used to measure the dimensional change of a 0.20-gram sample of HMX during its initial heating and then three days later during a 2nd heating. This HMX shows the beta to delta phase transition a second time, thereby confirming the back conversion from delta to beta phase HMX.
Date: August 5, 2004
Creator: Weese, R K; Burnham, A K & Maienschein, J L
Object Type: Article
System: The UNT Digital Library
cctbx news: Geometry restraints and other new features (open access)

cctbx news: Geometry restraints and other new features

None
Date: August 5, 2004
Creator: Grosse-Kunstleve, Ralf W.; Afonine, Pavel V. & Adams, Paul D.
Object Type: Article
System: The UNT Digital Library
Decanting of Neutralized H-Canyon Unirradiated Nuclear Material High Activity Waste Streams (open access)

Decanting of Neutralized H-Canyon Unirradiated Nuclear Material High Activity Waste Streams

An option to dispose of the High Activity Waste (HAW) stream from the processing of unirradiated materials directly to Saltstone is being evaluated to conserve High Level Waste (HLW) tank farm space and to reduce the future production of HLW glass logs. To meet the Saltstone Waste Acceptance Criteria (WAC), decanting the supernate from precipitated solids was proposed to reduce mercury and radionuclide levels in the waste. Only the caustic supernate will then be sent to Saltstone. Verification that the Saltstone WAC will be met has involved a series of laboratory studies using surrogate and actual HAW solutions from H-Canyon. The initial experiment involved addition of sodium hydroxide (NaOH) to a surrogate HAW test solution and subsequent decanting of the supernate away from the precipitated solids. The chemical composition of the surrogate solution was based on a composition defined from analyses of actual HAW solutions generated during dissolution of unirradiated nuclear materials in H-Canyon [1]. Results from testing the surrogate HAW solution were reported in Reference [2]. Information obtained from the surrogate test solution study was used to define additional experiments on actual HAW solutions obtained from H-Canyon. These experiments were conducted with samples from three different batches of HAW …
Date: August 5, 2004
Creator: BRONIKOWSKI, MICHAELG.
Object Type: Report
System: The UNT Digital Library
Mechanical design and engineering of the 3.9 GHZ, 3rd harmonic SRF system at Fermilab (open access)

Mechanical design and engineering of the 3.9 GHZ, 3rd harmonic SRF system at Fermilab

The mechanical development of the 3.9 GHz, 3rd Harmonic SRF System is summarized to include: the development of a full scale copper prototype cavity structure; the design of the niobium 3 cell and niobium 9 cell structures; the design of the helium vessel and cryostat; the HOM coupler design; and a preliminary look at the main coupler design. The manufacturing processes for forming, rolling, and e-beam welding the HOM coupler, cavity cells, and end tubes are also described. Due to the exotic materials and manufacturing processes used in this type of device, a cost estimate for the material and fabrication is provided. The 3rd harmonic design is organized via a web-based data management approach.
Date: August 5, 2004
Creator: al., Don Mitchell et
Object Type: Article
System: The UNT Digital Library
Development of the third harmonic SC cavity at Fermilab (open access)

Development of the third harmonic SC cavity at Fermilab

The third harmonic 3.9 GHz superconducting cavity was recently proposed by DESY for a new generation of high brightness photo-injector (TTF photoinjector-2) to compensate nonlinear distortion of the longitudinal phase space due to RF curvature of the 1.3 GHz TESLA cavities [1,2]. Installation of the 3rd harmonic cavity will allow us to generate ultra-short (<50 {micro}m rms) highly charged electron bunches with an extremely small transverse normalized emittance (<1 {micro}m). This is required to support a new generation of linear colliders, free electron lasers and synchrotron radiation sources. In this paper we present the current status of the 3rd harmonic cavity being developed at Fermilab. We discuss the design procedure, the building and testing of the copper and niobium half-cells and components, the design of input and HOM couplers.
Date: August 5, 2004
Creator: al., Nikolay Solyak et
Object Type: Article
System: The UNT Digital Library
Regulation of Development and Nitrogen Fixation in Anabaena (open access)

Regulation of Development and Nitrogen Fixation in Anabaena

The nitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 is being used as a simple model of microbial development and pattern formation in a multicellular prokaryotic organism. Anabaena reduces atmospheric nitrogen to ammonia in highly specialized, terminally differentiated cells called heterocysts. Anabaena is an important model system because of the multicellular growth pattern, the suspected antiquity of heterocyst development, and the contribution of fixed nitrogen to the environment. We are especially interested in understanding the molecular signaling pathways and genetic regulation that control heterocyst development. In the presence of an external source of reduced nitrogen, the differentiation of heterocysts is inhibited. When Anabaena is grown on dinitrogen, a one-dimensional developmental pattern of single heterocysts separated by approximately ten vegetative cells is established to form a multicellular organism composed of two interdependent cell types. The goal of this project is to understand the signaling and regulatory pathways that commit a vegetative cell to terminally differentiate into a nitrogen-fixing heterocyst. Several genes identified by us and by others were chosen as entry points into the regulatory network. Our research, which was initially focused on transcriptional regulation by group 2 sigma factors, was expanded to include group 3 sigma factors and their regulators …
Date: August 5, 2004
Creator: Golden, James W.
Object Type: Report
System: The UNT Digital Library
Strontium-90 Liquid Concentration Solubility Correlation in the Hanford Tank Waste Operations Simulator (open access)

Strontium-90 Liquid Concentration Solubility Correlation in the Hanford Tank Waste Operations Simulator

A new correlation was developed to estimate the concentration of strontium-90 in a waste solution based on total organic carbon. This correlation replaces the strontium-90 wash factors, and when applied in the Hanford Tank Waste Operations Simulator, significantly reduced the estimated quantity of strontium-90 in the delivered low-activity waste feed. This is thought to be a more realistic estimate of strontium-90 than using the wash-factor method.
Date: August 5, 2004
Creator: Hohl, T. H.; Place, D. E. & Wittman, R. S.
Object Type: Report
System: The UNT Digital Library
''CPT Theorem'' for Accelerators (open access)

''CPT Theorem'' for Accelerators

In this paper we attempt to reveal common features in evolution of various colliders' luminosity over commissioning periods. A simplified formula, ''CPT theorem'' or CP = T, is proposed which relates the time needed for commissioning T, the ''complexity'' of the machine C and performance increase goal P.
Date: August 5, 2004
Creator: Shiltsev, Vladimir
Object Type: Article
System: The UNT Digital Library
Results and Commissioning Issues From an Automated Demand Response Pilot (open access)

Results and Commissioning Issues From an Automated Demand Response Pilot

This paper describes a research project to develop and test Automated Demand Response hardware and software technology in large facilities. We describe the overall project and some of the commissioning and system design problems that took place. Demand Response (DR) is a set of activities to reduce or shift electricity use to improve the electric grid reliability purposes, manage electricity costs, and ensure that customers receive signals that encourage load reduction during times when the electric grid is near its capacity. There were a number of specific commissioning challenges in conducting this test including software compatibility, incorrect time zones, IT and EMCS failures, and hardware issues. The knowledge needed for this type of system commissioning combines knowledge of building controls with network management and knowledge of emerging information technologies.
Date: August 5, 2004
Creator: Piette, Mary Ann; Watson, Dave; Sezgen, Osman & Motegi, Naoya
Object Type: Article
System: The UNT Digital Library
Preparation of Peptide p-Nitroanilides using an Aryl Hydrazine Solid Support (open access)

Preparation of Peptide p-Nitroanilides using an Aryl Hydrazine Solid Support

Peptide p-nitroanilides are useful compounds for studying protease activity, however the poor nucleophilicity of p-nitroaniline makes their preparation difficult. We describe a new efficient approach for the Fmoc-based synthesis of peptide p-nitroanilides using an aryl hydrazine resin. Mild oxidation of the peptide hydrazide resin yields a highly reactive acyl diazene, which efficiently reacts with weak nucleophiles. We have prepared several peptide p-nitroanilides, including substrates for the Lethal Factor protease from B. anthracis.
Date: August 5, 2004
Creator: Kwon, Y; Welsh, K; Mitchell, A R & Camarero, J A
Object Type: Article
System: The UNT Digital Library
A Prehistorical Record of Cultural Eutrophication from Crawford Lake, Canada (open access)

A Prehistorical Record of Cultural Eutrophication from Crawford Lake, Canada

Cultural eutrophication--the process by which human activities increase nutrient input rates to aquatic ecosystems and thereby cause undesirable changes in surface-water quality--is generally thought to have begun with the start of the industrial era. The prehistoric dimension of human impacts on aquatic ecosystems remains relatively undescribed, particularly in North America. Here we present fossil plankton data (diatoms and rotifers), organic and inorganic carbon accumulations, and carbon isotope ratios from a 1000-yr sediment core record from Crawford Lake, Ontario, Canada. The data documents increased nutrient input to Crawford Lake caused by Iroquoian horticultural activity from A.D. 1268 to 1486 and shows how this increased nutrient input elevated lake productivity, caused bottom-water anoxia, and irreversibly altered diatom community structure within just a few years. Iroquoian settlement in the region declined in the fifteenth century, yet diatom communities and lake circulation never recovered to the predisturbance state. A second phase of cultural eutrophication starting in A.D. 1867, initiated by Canadian agricultural disturbance, increased lake productivity but had comparatively less of an impact on diatom assemblages and carbon-storage pathways than the initial Iroquoian disturbance. This study deepens our understanding of the impact of cultural eutrophication on lake systems, highlights the lasting influence of initial …
Date: August 5, 2004
Creator: Ekdahl, E J; Teranes, J; Guilderson, T; Turton, C L; McAndrews, J H; Wittkop, C A et al.
Object Type: Article
System: The UNT Digital Library
Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry (open access)

Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry

Even-order Legendre polynomial (PN) expansion approximations of the neutron transport equation have historically seen only limited practical application. Research in the last decade [1] has resolved one of the historical theoretical objections [2] to the use of even-order PN approximations in planar geometry, namely the ambiguity in the prescription of boundary conditions as a result of an odd number of unknowns. This research also demonstrated the P2 approximation to be more accurate than the P1 approximation in planar geometry away from boundary layers and material interfaces. Neither the P1 nor the P2 approximation is convincingly more accurate near material interfaces. This progress motivated the reexamination of the multidimensional simplified P2 (SP2) approximation [3], the development of P2 approximations for planar geometry stochastic transport problems [4], and the examination of the P2 and SP2 approximations as a synthetic acceleration technique for the discrete ordinates equations.
Date: August 5, 2004
Creator: Brantely, P S
Object Type: Article
System: The UNT Digital Library
Accuracy of Density Functional Theory for First-Principles Simulations of Water (open access)

Accuracy of Density Functional Theory for First-Principles Simulations of Water

None
Date: August 5, 2004
Creator: Schwegler, E.; Grossman, J.; Draeger, E.; Allesch, M.; Gygi, F. & Galli, G.
Object Type: Article
System: The UNT Digital Library
Application of Neutron Correlation Techniques to Warhead Authentication: Feasibility and Conceptual Requirements?Monte Carlo Simulations and Statistical Analysis (open access)

Application of Neutron Correlation Techniques to Warhead Authentication: Feasibility and Conceptual Requirements?Monte Carlo Simulations and Statistical Analysis

We explore the feasibility of using Feynman moments as attributes of fissile material in warhead authentication measurements. We present results of computer simulations of neutron correlation measurements to validate and inform the application of the method to measurements in an arms control scenario. We establish the robustness of the method for use in automated measuring equipment that protects classified or sensitive data using an information barrier. Drawing from our results, we define high-level requirements to govern the design process, and guide the construction of a prototype.
Date: August 5, 2004
Creator: Frank, M. I. & Wolford, J. K.
Object Type: Report
System: The UNT Digital Library
An Upgrade for the Advanced Light Source (open access)

An Upgrade for the Advanced Light Source

One of the first third-generation synchrotron light sources, the ALS, has been operating for almost a decade at Berkeley Lab, where experimenters have been exploiting its high brightness for forefront science. However, accelerator and insertion-device technology have significantly changed since the ALS was designed. As a result, the performance of the ALS is in danger of being eclipsed by that of newer, more advanced sources. The ALS upgrade that we are planning includes full-energy, top-off injection with higher storage-ring current and the replacement of five first-generation insertion devices with nine state-of-the art insertion devices and four new application-specific beamlines now being identified in a strategic planning process. The upgrade will help keep the ALS at the forefront of soft x-ray synchrotron light sources for the next two decades.
Date: August 5, 2004
Creator: Chemla, Daniel S.; Feinberg, Benedict; Hussain, Zahid; Kirz,Janos; Krebs, Gary F.; Padmore, Howard A. et al.
Object Type: Article
System: The UNT Digital Library
The QCD/SM Working Group: Summary Report (open access)

The QCD/SM Working Group: Summary Report

Among the many physics processes at TeV hadron colliders, we look most eagerly for those that display signs of the Higgs boson or of new physics. We do so however amid an abundance of processes that proceed via Standard Model (SM) and in particular Quantum Chromodynamics (QCD) interactions, and that are interesting in their own right. Good knowledge of these processes is required to help us distinguish the new from the known. Their theoretical and experimental study teaches us at the same time more about QCD/SM dynamics, and thereby enables us to further improve such distinctions. This is important because it is becoming increasingly clear that the success of finding and exploring Higgs boson physics or other New Physics at the Tevatron and LHC will depend significantly on precise understanding of QCD/SM effects for many observables. To improve predictions and deepen the study of QCD/SM signals and backgrounds was therefore the ambition for our QCD/SM working group at this Les Houches workshop. Members of the working group made significant progress towards this on a number of fronts. A variety of tools were further developed, from methods to perform higher order perturbative calculations or various types of resummation, to improvements in …
Date: August 5, 2004
Creator: al., M. Dobbs et
Object Type: Article
System: The UNT Digital Library
Baseline information development for energy smart schools -- applied research, field testing and technology integration (open access)

Baseline information development for energy smart schools -- applied research, field testing and technology integration

The original scope of work was to obtain and analyze existing and emerging data in four states: California, Florida, New York, and Wisconsin. The goal of this data collection was to deliver a baseline database or recommendations for such a database that could possibly contain window and daylighting features and energy performance characteristics of Kindergarten through 12th grade (K-12) school buildings (or those of classrooms when available). In particular, data analyses were performed based upon the California Commercial End-Use Survey (CEUS) databases to understand school energy use, features of window glazing, and availability of daylighting in California K-12 schools. The outcomes from this baseline task can be used to assist in establishing a database of school energy performance, assessing applications of existing technologies relevant to window and daylighting design, and identifying future R&D needs. These are in line with the overall project goals as outlined in the proposal. Through the review and analysis of this data, it is clear that there are many compounding factors impacting energy use in K-12 school buildings in the U.S., and that there are various challenges in understanding the impact of K-12 classroom energy use associated with design features of window glazing and skylight. First, …
Date: August 5, 2004
Creator: Xu, Tengfang & Piette, Mary Ann
Object Type: Report
System: The UNT Digital Library
Overview of the Coupled Model Intercomparison Project (CMIP) (open access)

Overview of the Coupled Model Intercomparison Project (CMIP)

The Coupled Model Intercomparison Project (CMIP) is designed to allow study and intercomparison of multi-model simulations of present-day and future climate. The latter are represented by idealized forcing of compounded 1% per year CO2 increase to the time of CO2 doubling near year 70 in simulations with global coupled models that contain, typically, components representing atmosphere, ocean, sea ice and land surface. Results from CMIP diagnostic subprojects were presented at the Second CMIP Workshop held at the Max Planck Institute for Meteorology in Hamburg, Germany, in September, 2003. Significant progress in diagnosing and understanding results from global coupled models has been made since the First CMIP Workshop in Melbourne, Australia in 1998. For example, the issue of flux adjustment is slowly fading as more and more models obtain stable multi-century surface climates without them. El Nino variability, usually about half the observed amplitude in the previous generation of coupled models, is now more accurately simulated in the present generation of global coupled models, though there are still biases in simulating the patterns of maximum variability. Typical resolutions of atmospheric component models contained in coupled models is now usually around 2.5 degrees latitude-longitude, with the ocean components often having about twice …
Date: August 5, 2004
Creator: Meehl, Gerald A.; Covey, Curt; McAvaney, Bryant; Latif, Mojib & Stouffer, Ronald J.
Object Type: Article
System: The UNT Digital Library