Proton irradiation effects on 2Gb flash memory (open access)

Proton irradiation effects on 2Gb flash memory

The authors report total ionizing dose and single event effects on 2Gb Samsung flash memory devices after exposure to 200 MeV protons to various doses up to 83 krad(Si). They characterize observed failures and single event upsets on 22 devices from two different lots. Devices from both lots are robust to greater than 20 krad(Si) although they see evidence for lot-to-lot variation where only one lot appears robust up to about 50 krad(Si). Single event upsets are observed at a relatively low rate and are consistent with single isolated bit flips within registers that transfer bits to and from the flash memory cells.
Date: August 18, 2004
Creator: Wester, William; Nelson, Charles & Marriner, John
Object Type: Article
System: The UNT Digital Library
REACTION MECHANISMS OF MAGNESIUM SILICATES WITH CARBON DIOXIDE IN MICROWAVE FIELDS (open access)

REACTION MECHANISMS OF MAGNESIUM SILICATES WITH CARBON DIOXIDE IN MICROWAVE FIELDS

The objective of the investigation was to determine whether microwave fields would enhance the reactions of CO{sub 2} with silicates that are relevant to the sequestration of carbon dioxide. Three sets of experiments were conducted. (1) Serpentine and CO{sub 2} were reacted directly at one atmosphere pressure in a microwave furnace. Little reaction was observed. (2) Serpentine was dehydroxylated in a microwave furnace. The reaction was rapid, reaching completion in less than 30 minutes. A detailed investigation of this reaction produced an S-shaped kinetics curve, similar to the kinetics from dehydroxylating serpentine in a resistance furnace, but offset to 100 C lower temperature. This set of experiments clearly demonstrates the effect of microwaves for enhancing reaction kinetics. (3) Reactions of serpentine with alkaline carbonates and in acid solution were carried out in a microwave hydrothermal apparatus. There was a greatly enhanced decomposition of the serpentine in acid solution but, at the temperature and pressure of the reaction chamber (15 bars; 200 C) the carbonates did not react. Overall, microwave fields, as expected, enhance silicate reaction kinetics, but higher CO{sub 2} pressures are needed to accomplish the desired sequestration reactions.
Date: February 18, 2004
Creator: White, William B.; Silsbee, Michael R. & Kearns, B. Joe
Object Type: Report
System: The UNT Digital Library
The Debt Limit: The Ongoing Need for Increases (open access)

The Debt Limit: The Ongoing Need for Increases

The surpluses over the four fiscal years 1998-2001 reduced debt held by the public by $448 billion. More than offsetting this debt reduction, the surpluses credited to debt-holding government accounts (which generally must invest the surpluses in federal debt), increased their holdings by $853 billion over the same period. The combination ($853 billion minus $448 billion) raised total federal debt by $405 billion. During 2002, debt subject to limit increased enough to reach the then current statutory debt limit, $5.95 trillion, in early April and again in May 2002. Congress passed and the President signed legislation (P.L. 108-24) increasing the limit to $6.4 trillion in June 2002.
Date: November 18, 2004
Creator: Winters, Philip D.
Object Type: Report
System: The UNT Digital Library
Co2 geological sequestration (open access)

Co2 geological sequestration

Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a …
Date: November 18, 2004
Creator: Xu, Tianfu
Object Type: Article
System: The UNT Digital Library
Difference between BPM reading one bunch and the average of multi-bunch in Booster (open access)

Difference between BPM reading one bunch and the average of multi-bunch in Booster

Differences caused by BPM reading one bunch and multi-bunch average need to be well understood before the beam parameters, such as the synchrotron tune, betatron tune, and chromaticity, are extracted from those BPM data. It is easy to perform such a study using numerical simulation other than modifying the BPM electronics.
Date: August 18, 2004
Creator: Yang, Xi
Object Type: Report
System: The UNT Digital Library
First-order Isostructural Mott transition in highly-compressed MnO (open access)

First-order Isostructural Mott transition in highly-compressed MnO

We present evidence for an isostructural, first-order Mott transition in MnO at 105 {+-} 5 GPa, based on high-resolution x-ray emission spectroscopy and angle-resolved x-ray diffraction data. The pressure-induced structural/spectral changes provide a coherent picture of MnO phase transitions from paramagnetic B1 to antiferromagnetic distorted B1 at 30 GPa, to paramagnetic B8 at 90 GPa, and to diamagnetic B8 at 105 {+-} 5 GPa. The last is the Mott transition, accompanied by a complete loss of magnetic moment, an {approx}6.6% volume collapse and a visual appearance change to metallic luster consistent with recent resistivity measurements.
Date: June 18, 2004
Creator: Yoo, C
Object Type: Article
System: The UNT Digital Library
The Higgs Working Group: Summary report (open access)

The Higgs Working Group: Summary report

In this working group we have investigated the prospects for Higgs boson searches at the Tevatron and LHC and, in particular, the potential of these colliders to determine the Higgs properties once these particles have been found. The analyses were done in the framework of the Standard Model (SM) and its supersymmetric extensions as the minimal (MSSM) and next-to-minimal (NMSSM) supersymmetric extensions. The work for the discovery potential of the LHC mainly concentrated on the difficult regions of previous analyses as those which are plagued by invisible Higgs decays and Higgs decays into supersymmetric particles. Moreover, the additional signatures provided by the weak vector-boson fusion process (WBF) have been addressed and found to confirm the results of previous analyses. A major experimental effort has been put onto charged Higgs boson analyses. The final outcome was a significant improvement of the discovery potential at the Tevatron and LHC than previous analyses suggested. For an accurate determination of Higgs boson couplings, the theoretical predictions for the signal and background processes have to be improved. A lot of progress has been made during and after this workshop for the gluon-fusion gg {yields} H + (0, 1, 2jets) and the associated t{bar t}H production …
Date: March 18, 2004
Creator: al., D. Cavalli et
Object Type: Article
System: The UNT Digital Library
The Beyond the standard model working group: Summary report (open access)

The Beyond the standard model working group: Summary report

In this working group we have investigated a number of aspects of searches for new physics beyond the Standard Model (SM) at the running or planned TeV-scale colliders. For the most part, we have considered hadron colliders, as they will define particle physics at the energy frontier for the next ten years at least. The variety of models for Beyond the Standard Model (BSM) physics has grown immensely. It is clear that only future experiments can provide the needed direction to clarify the correct theory. Thus, our focus has been on exploring the extent to which hadron colliders can discover and study BSM physics in various models. We have placed special emphasis on scenarios in which the new signal might be difficult to find or of a very unexpected nature. For example, in the context of supersymmetry (SUSY), we have considered: how to make fully precise predictions for the Higgs bosons as well as the superparticles of the Minimal Supersymmetric Standard Model (MSSM) (parts III and IV); MSSM scenarios in which most or all SUSY particles have rather large masses (parts V and VI); the ability to sort out the many parameters of the MSSM using a variety of signals …
Date: March 18, 2004
Creator: al., G. Azuelos et
Object Type: Article
System: The UNT Digital Library
Pulser for the Tevatron electron lens gun (open access)

Pulser for the Tevatron electron lens gun

To compensate for beam-beam interaction in Tevatron, an ''electron lens'' is considered to be an effective instrument. When a bunch of electrons with energy in the range (10-16) kV is overlapping with a bunch of antiprotons, the resulting focusing force for antiprotons can be adjusted by changing the electron beam current and by profiling its radial distribution. There exist several scenarios of how the system must function. According to one of them, an electron gun that supplies electrons must be fed by voltage pulses that follow with the frequency of antiproton bunches circulating in the Tevatron, which is about 2.5 MHz. To provide focusing tailored for each individual antiproton bunch, a modulator of the gun (pulser) must allow pulse-to-pulse voltage change. This report will cover main approaches to a design of a pulser for use with the gun of the Tevatron Electron Lens.
Date: May 18, 2004
Creator: al., Iouri Terechkine et
Object Type: Article
System: The UNT Digital Library
Fiber positioning and MRS response (open access)

Fiber positioning and MRS response

This paper provides experimental results on the dependence of the output signal from small-area silicon photodetectors, such as MRS (Metal-Resistive layer-Semiconductor) photodiodes, on the fiber alignment.
Date: May 18, 2004
Creator: al., Pavel Polozov et
Object Type: Report
System: The UNT Digital Library
Corrosion Behavior of Titanium Grade 7 in Fluoride-Containing NaCl Brines (open access)

Corrosion Behavior of Titanium Grade 7 in Fluoride-Containing NaCl Brines

Titanium Grade 7 (UNS R52400) is a titanium-based alloy with 0.12-0.25% Pd. The addition of the small amount of palladium is to ennoble the corrosion potential of Ti, thus improving the corrosion resistance of titanium in reducing environments. In most aqueous environments, Ti and Ti alloys demonstrate excellent corrosion resistance due to the protective oxide film that forms spontaneously and remains stable on the surface. However, Ti and Ti alloys are susceptible to corrosion in fluoride-containing environments due to the formation of complexes such as TiF{sub 6}{sup 2-} and TiF{sub 6}{sup 3-}, which are stable and soluble in electrolyte solutions. Without the presence of fluoride, only slight effects from [Cl{sup -}], pH and temperature have been reported [1]. It has been reported that the kinetics of passive corrosion of titanium in neutral solutions and controlled by the migration of the defects in the oxide across the surface film [2]. Thus, the increase in thickness and improvement in film properties, by thermal oxidation, would lead to a significant decrease in the susceptibility to film breakdown and in the passive corrosion rate. This report summarizes recent experiment results in studies of the environmental influence on the corrosion behavior of Titanium Grade 7 …
Date: May 18, 2004
Creator: unknown
Object Type: Article
System: The UNT Digital Library
The NCAA and Due Process: Legal Issues (open access)

The NCAA and Due Process: Legal Issues

None
Date: August 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Nuclear Arms Control: The U.S.-Russian Agenda (open access)

Nuclear Arms Control: The U.S.-Russian Agenda

None
Date: October 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Open Ocean Aquaculture (open access)

Open Ocean Aquaculture

None
Date: August 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Private Rights of Action and the Wiretap Act: The “DirecTV” Litigation (open access)

Private Rights of Action and the Wiretap Act: The “DirecTV” Litigation

None
Date: August 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Sexual Harassment, Constructive Discharge, and Employers’ Affirmative Defenses: The U.S. Supreme Court Decision in Pennsylvania State Police v. Suders (open access)
Social Security: The Government Pension Offset (open access)

Social Security: The Government Pension Offset

None
Date: February 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Taxpayer Protection and IRS Accountability Act of 2003, H.R. 1528, and Tax Administration Good Government Act, S. 882 (open access)

Taxpayer Protection and IRS Accountability Act of 2003, H.R. 1528, and Tax Administration Good Government Act, S. 882

None
Date: June 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Visa Waiver Program (open access)

Visa Waiver Program

None
Date: October 18, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library