Resource Type

Country

191 Matching Results

Results open in a new window/tab.

Plasma-Enhanced SCR of NOx in Simulated Heavy-Duty Exhaust: Sulfur, Hydrocarbon, and Temperature Effects (open access)

Plasma-Enhanced SCR of NOx in Simulated Heavy-Duty Exhaust: Sulfur, Hydrocarbon, and Temperature Effects

None
Date: August 20, 2000
Creator: Aardahl, C. L.
System: The UNT Digital Library
Influence of EGR on Component Durability (open access)

Influence of EGR on Component Durability

None
Date: August 20, 2000
Creator: Abi-Akar, Hind
System: The UNT Digital Library
Numerical and Experimental Studies of HCCI combustion (open access)

Numerical and Experimental Studies of HCCI combustion

None
Date: August 20, 2000
Creator: Aceves, Salvador M.
System: The UNT Digital Library
Detection of Pancreatic Cancer miRNA with Biocompatible Nitrogen-Doped Graphene Quantum Dots (open access)

Detection of Pancreatic Cancer miRNA with Biocompatible Nitrogen-Doped Graphene Quantum Dots

Article detects the presence of a specific pancreatic cancer-derived miRNA (pre-miR-132) using the fluorescence properties of biocompatible nitrogen-doped graphene quantum dots (NGQDs) synthesized using a bottom-up approach from a single glucosamine precursor. This non-invasive approach allows cancer-specific miRNA detection to facilitate early diagnosis of various forms of cancer.
Date: August 20, 2022
Creator: Ajgaonkar, Ryan; Lee, Bong; Valimukhametova, Alina; Nguyen, Steven; Gonzalez-Rodriguez, Roberto; Coffer, Jeffery et al.
System: The UNT Digital Library
Commissioning of the LCLS Linac and Bunch Compressors (open access)

Commissioning of the LCLS Linac and Bunch Compressors

The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through the first bunch compressor, was commissioned in the spring and summer of 2007. The second phase of commissioning, including the second bunch compressor and various main linac modifications, was completed in January through August of 2008. We report here on experience gained during this second phase of machine commissioning, including the injector, the first and second bunch compressor stages, the linac up to 14 GeV, and beam stability measurements. The final commissioning phase, including the undulator and the long transport line from the linac, is set to begin in December 2008, with first light expected in July 2009.
Date: August 20, 2008
Creator: Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma#, P. et al.
System: The UNT Digital Library
Smart Engines Via Advanced Model Based Controls (open access)

Smart Engines Via Advanced Model Based Controls

A ''new'' process for developing control systems - Less engine testing - More robust control system - Shorter development cycle time - ''Smarter'' approach to engine control - On-board models describe engine behavior - Shorter, systematic calibration process - Customer and legislative requirements designed-in.
Date: August 20, 2000
Creator: Allain, Marc
System: The UNT Digital Library
Review of 2XIIB project (open access)

Review of 2XIIB project

A review is given of the 2X project, including project history and recent results, with the intent that both those new to CTR engineering and those people familiar with its progress will benefit. The current 2XII Program plan is reviewed, with emphasis on the major device fabrication underway at the present time. This construction consists primarily of a new magnet for 2XII, and has been designated 2XIIB. The injection of a 800-A neutral beam is described. The final portion of the paper is a progress report and a summary of cost estimates and scheduling. (auth)
Date: August 20, 1973
Creator: Anderson, C.J.
System: The UNT Digital Library
Review of 2XIIB project (open access)

Review of 2XIIB project

From fifth sympoaium on engineering problems of fusion research; Princeton, New Jersey, USA (6 Nov 1973). A review is given of the 2X project, including project history and recent results, with the irtent that both those new to controlled thermonuclear research engineering and those people familiar with its progress will benefit. The current 2XII program plan is reviewed, with emphasis on the major device fubrication underway at the present time. This construction consiats primarily of a new magnet for 2XII, and has been designated 2XIIB. The injection of a 600A neutral beam is described. The ftnal portion of the paper is a progress report and a summary of cost estimates and scheduling. (MOW)
Date: August 20, 1973
Creator: Anderson, C.J.
System: The UNT Digital Library
Update of Time-Dependent CP Asymmetry Measurements in b to c-cbar-s Decays (open access)

Update of Time-Dependent CP Asymmetry Measurements in b to c-cbar-s Decays

We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465 {+-} 5) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II B factory. The time-dependent CP asymmetry parameters measured from J/{psi}K{sub S}{sup 0}, J/{psi}K{sub L}{sup 0}, {psi}(2S)K{sub S}{sup 0}, {chi}{sub c1}K{sub S}{sup 0}, {eta}{sub c}K{sub S}{sup 0}, and J/{psi}K*{sup 0} decays are: (1) C{sub f} = 0.026 {+-} 0.020(stat) {+-} 0.016(syst); and (2) S{sub f} = 0.691 {+-} 0.029(stat) {+-} 0.014(syst).
Date: August 20, 2008
Creator: Aubert, B.
System: The UNT Digital Library
Evidence for CP violation in B0 to J/Psi pi0 Decays (open access)

Evidence for CP violation in B0 to J/Psi pi0 Decays

None
Date: August 20, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
System: The UNT Digital Library
Electrically-Assisted Turbocharger Development for Performance and Emissions (open access)

Electrically-Assisted Turbocharger Development for Performance and Emissions

Turbocharger transient lag inherently imposes a tradeoff between a robust engine response to transient load shifts and exhaust emissions. By itself, a well matched turbocharger for an engine has limited flexibility in improving this transient response. Electrically-assisted turbocharging has been seen as an attractive option to improve response and lower transient emissions. This paper presents the results of a multi-year joint CRADA between DDC and ORNL. Virtual lab diesel simulation models characterized the performance improvement potential of an electrically assisted turbocharger technology. Operating requirements to reduce transient duration between load shift time by up to 50% were determined. A turbomachine has been conceptualized with an integrated motor-generator, providing transient burst boost plus energy recovery capability. Numerous electric motor designs were considered, and a prototype motor was developed, fabricated, and is undergoing tests. Power controls have been designed and fabricated.
Date: August 20, 2000
Creator: Bailey, Milton
System: The UNT Digital Library
Development of mixed-conducting ceramic membrane for hydrogen separation. (open access)

Development of mixed-conducting ceramic membrane for hydrogen separation.

The Office of Fossil Energy of the US Department of Energy is formulating ''Vision 21,'' a program aimed at developing technologies for highly efficient power and coproduction plants that discharge almost no pollutants and close the carbon cycle. An integrated gasification combined cycle (IGCC) system is a likely modular component of a Vision 21 coproduction plant. IGCC technology is ideally suited for the coproduction of electricity and high-quality transportation fuel and/or a host of high-value chemicals. As part of the IGCC system, high-temperature membranes for separating hydrogen from coal gasification and other partial-oxidation-product streams are being considered. Thin and dense ceramic membranes fabricated from mixed protonic and electronic conductors provide a simple, efficient means for separating hydrogen from gas streams. Dense mixed-conducting ceramic membranes effect transport via ion- and electron-conducting mechanisms. Because these membranes have no interconnected porosity, selectively for hydrogen is nearly 100%. Hydrogen separation is achieved in a nongalvanic mode, i.e., without the need for electrodes and external power supply to drive the separation. BaCeO{sub 3}-based materials exhibit protonic conductivity that is significantly higher than its electronic conductivity. To enhance the electronic conductivity and increase hydrogen permeation, we have fabricated BaCeO{sub 3}-containing cermet membranes and used them in …
Date: August 20, 1999
Creator: Balachandran, U.; Dorris, S. E. & Lee, T. H.
System: The UNT Digital Library
Experiments and Analysis of DPF Loading and Regeneration (open access)

Experiments and Analysis of DPF Loading and Regeneration

Particulate filter system consists of a filter and a regeneration strategy Commercial filters are very effective at removing PM, but regeneration is a challenge. In addition to removal of PM if is important to reduce other pollutants including NO, from diesel engine exhaust Particulate filter regeneration strategy can include catalysts, fuel additives, engine control, and fuel injection Regeneration 5M?-500 C without catalyst Near 350 C with fuel additive or catalyst coated DPF
Date: August 20, 2000
Creator: Balakrishnan, Krishnan
System: The UNT Digital Library
A fourth order accurate adaptive mesh refinement method forpoisson's equation (open access)

A fourth order accurate adaptive mesh refinement method forpoisson's equation

We present a block-structured adaptive mesh refinement (AMR) method for computing solutions to Poisson's equation in two and three dimensions. It is based on a conservative, finite-volume formulation of the classical Mehrstellen methods. This is combined with finite volume AMR discretizations to obtain a method that is fourth-order accurate in solution error, and with easily verifiable solvability conditions for Neumann and periodic boundary conditions.
Date: August 20, 2004
Creator: Barad, Michael & Colella, Phillip
System: The UNT Digital Library
Study of alpha-decay damage in a glass-bonded, sodalite ceramic waste. (open access)

Study of alpha-decay damage in a glass-bonded, sodalite ceramic waste.

A glass-bonded, sodalite ceramic waste form that contains fission products, uranium, and plutonium is intended for disposition in a geologic repository. Over the many years the waste is expected to be in the repository, there is a potential for waste form degradation due to alpha decay damage. To investigate the effects of alpha-decay damage in glass-bonded, sodalite ceramic waste forms, several waste forms were produced with a {sup 238}Pu loading of 1.8 weight percent. This loading is roughly ten times greater than the plutonium loading for all isotopes in the waste form intended for the repository. Due to the higher specific activity of {sup 238}Pu as well as a higher fraction of total plutonium, the same number of alpha decays per gram of material has been achieved after four years as a waste form of nominal composition after ten thousand years. This paper describes the results of different tests near the completion of a four-year study. Trends of these {sup 238}Pu-doped waste forms include volume expansion of crystalline phases and possible increases in the release rates of several elements in the chemical durability tests. There have not yet been any indications of macroscopic swelling by density measurements, amorphization by x-ray …
Date: August 20, 2002
Creator: Barber, T. L.; DiSanto, T.; Frank, S. M.; Goff, K. M.; Johnson, S. G.; Jue, J.-F. et al.
System: The UNT Digital Library
Study of neutron noise from reflected, metal assemblies with criticality safety applications in mind (open access)

Study of neutron noise from reflected, metal assemblies with criticality safety applications in mind

The author studied the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. The calculated multiplication factors of the assemblies are 0.59, 0.74, 0.82, and 0.92. The author studied three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. They are: (1) variance-to-mean ratio of the counts in a time bin (V/M); (2) covariance-to-mean ratio of the counts in a common time bin from two different detectors (C/M); and (3) covariance-to-mean ratio of the counts from a single detector in two adjacent time bins of equal length, which the author calls the serial-covariance-to-mean ratio (SC/M). The performances of the three discriminators were not greatly different, but a hierarchy did emerge: SC/M greater than or equal to V/M greater than or equal to C/M. An example of some results: in the neighborhood of k = 0.6 the ..delta..k required for satisfactory discrimination varies from about 3% to 7% as detector solid angle varies from 19% to 5%. In the neighborhood of k = 0.8 the corresponding ..delta..ks are 1% and 2%. The noise analysis techniques studied …
Date: August 20, 1985
Creator: Barnett, C. S.
System: The UNT Digital Library
Comparative genomic analysis reveals a distant liver enhancer upstream of the COUP-TFII gene (open access)

Comparative genomic analysis reveals a distant liver enhancer upstream of the COUP-TFII gene

COUP-TFII is a central nuclear hormone receptor that tightly regulates the expression of numerous target lipid metabolism genes in vertebrates. However, it remains unclear how COUP-TFII itself is transcriptionally controlled since studies with its promoter and upstream region fail to recapitulate the genes liver expression. In an attempt to identify liver enhancers in the vicinity of COUP-TFII, we employed a comparative genomic approach. Initial comparisons between humans and mice of the 3,470kb gene poor region surrounding COUP-TFII revealed 2,023 conserved non-coding elements. To prioritize a subset of these elements for functional studies, we performed further genomic comparisons with the orthologous pufferfish (Fugu rubripes) locus and uncovered two anciently conserved non-coding sequences (CNS) upstream of COUP-TFII (CNS-62kb and CNS-66kb). Testing these two elements using reporter constructs in liver (HepG2) cells revealed that CNS-66kb, but not CNS-62kb, yielded robust in vitro enhancer activity. In addition, an in vivo reporter assay using naked DNA transfer with CNS-66kb linked to luciferase displayed strong reproducible liver expression in adult mice, further supporting its role as a liver enhancer. Together, these studies further support the utility of comparative genomics to uncover gene regulatory sequences based on evolutionary conservation and provide the substrates to better understand the …
Date: August 20, 2004
Creator: Baroukh, Nadine; Ahituv, Nadav; Chang, Jessie; Shoukry, Malak; Afzal, Veena; Rubin, Edward M. et al.
System: The UNT Digital Library
Electrical conductivity of fluid oxygen at high pressures (open access)

Electrical conductivity of fluid oxygen at high pressures

Electrical conductivities of fluid oxygen were measured between 30 and 80 GPa at a few 1000 K. These conditions were achieved with a reverberating shock wave technique. The measured conductivities were several orders of magnitude lower than measured previously on the single shock Hugoniot because of lower temperatures achieved under shock reverberation. Extrapolation of these data suggests that the minimum metallic conductivity of a metal will be reached near 100 GPa.
Date: August 20, 1999
Creator: Bastea, M; Mitchell, A C & Nellis, W J
System: The UNT Digital Library
Parental transgenerational epigenetic inheritance related to dietary crude oil exposure in Danio rerio (open access)

Parental transgenerational epigenetic inheritance related to dietary crude oil exposure in Danio rerio

Article investigating the transgenerational inheritance from both parental lines in zebrafish. Adult zebrafish were separated into female and male groups exposed for 21 days to either a control diet or to a diet containing water accommodated fractions of crude oil. To determine the maternal and paternal influence on their offspring, the authors evaluated responses from molecular to whole organismal levels in both generations.
Date: January 22, 2020
Creator: Bautista, Naim M.; Crespel, Amélie; Crossley, Janna; Padilla, Pamela A. & Burggren, Warren W.
System: The UNT Digital Library
Liquid Cryogen Absorber for MICE* (open access)

Liquid Cryogen Absorber for MICE*

The Muon Ionization Cooling Experiment (MICE) will test ionization cooling of muons. In order to have effective ionization cooling, one must use an absorber that is made from a low-z material. The most effective low z materials for ionization cooling are hydrogen, helium, lithium hydride, lithium and beryllium, in that order. In order to measure the effect of material on cooling, several absorber materials must be used. This report describes a liquid-hydrogen absorber that is within a pair of superconducting focusing solenoids. The absorber must also be suitable for use with liquid helium. The following absorber components are discussed in this report; the absorber body, its heat exchanger, the hydrogen system, and the hydrogen safety. Absorber cooling and the thin windows are not discussed here.
Date: August 20, 2005
Creator: Baynham, D. E.; Bish, P.; Bradshaw, T. W.; Cummings, M. A.; Green, M. A.; Ishimoto, S. et al.
System: The UNT Digital Library
The Influence of Light Weight Materials on Fuel Economy and Emissions in Heavy Duty Diesel Engine (open access)

The Influence of Light Weight Materials on Fuel Economy and Emissions in Heavy Duty Diesel Engine

Technologies being developed that will allow for the substitution of aluminum for cast iron in engine heads and blocks, while maintaining performance and durability. Development of lightweight diesel engine technology: funded by NAVY, DOE and TACOM
Date: August 20, 2000
Creator: Becker, Paul C.
System: The UNT Digital Library
NOX REDUCTION FOR LEAN EXHAUST USING PLASMA ASSISTED CATALYSIS (open access)

NOX REDUCTION FOR LEAN EXHAUST USING PLASMA ASSISTED CATALYSIS

Currently CARB estimates on road diesel vehicles contribute 50% of the NOX and 78% of the particulates being discharged from mobile sources. Diesel emissions obviously must be reduced if future air quality targets are to be met. A critical technological barrier exists because there are no commercial technologies available, which can reduce NOX from diesel (lean), exhaust containing 5-15% O2 concentration. One promising approach to reducing NOX and particulates from diesel exhaust is to use a combination of plasma with catalyst. Plasma can be generated thermally or non-thermally. Thermal plasma is formed by heating the system to an exceedingly high temperature (>2000 C). High temperature requirements for plasma makes thermal plasma inefficient and requires skillful thermal management and hence is considered impractical for mobile applications. Non-thermal plasma directs electrical energy into the creation of free electrons, which in turn react with gaseous species thus creating plasma. A combination of non-thermal plasma with catalysts can be referred to Plasma Assisted Catalysts or PAC. PAC technology has been demonstrated in stationary sources where non-thermal plasma catalysis is carried out in presence of NH3 as a reductant. In stationary applications NO is oxidized to HNO3 and then into ammonium nitrate where it is …
Date: August 20, 2000
Creator: Bhatt, B.
System: The UNT Digital Library
Nuclear weapons, nuclear effects, nuclear war (open access)

Nuclear weapons, nuclear effects, nuclear war

This paper provides a brief and mostly non-technical description of the militarily important features of nuclear weapons, of the physical phenomena associated with individual explosions, and of the expected or possible results of the use of many weapons in a nuclear war. Most emphasis is on the effects of so-called ``strategic exchanges.``
Date: August 20, 1991
Creator: Bing, G. F.
System: The UNT Digital Library
Use of induction linacs with nonlinear magnetic drive as high average power accelerators (open access)

Use of induction linacs with nonlinear magnetic drive as high average power accelerators

The marriage of induction linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 Mev/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator is under construction at Lawrence Livermore National Laboratory (LLNL) to allow us to demonstrate some of these concepts. Progress on this project is reported here.
Date: August 20, 1984
Creator: Birx, D. L.; Cook, E. G.; Hawkins, S. A.; Newton, M. A.; Poor, S. E.; Reginato, L. L. et al.
System: The UNT Digital Library