Investigations of Localized Corrosion of Stainless Steel after Exposure to Supercritical CO2 (open access)

Investigations of Localized Corrosion of Stainless Steel after Exposure to Supercritical CO2

Severe localized corrosion of a 316 stainless steel autoclave occurred during investigating Type H Portland cement stability in 0.16 M CaCl{sub 2} + 0.02 M MgCl{sub 2} + 0.82 M NaCl brine in contact with supercritical CO{sub 2} containing 4% O{sub 2}. The system operated at 85 C and pressure of 29 MPa. However, no corrosion was observed in the same type of autoclave being exposed to the same environment, containing Type H Portland cement cylindrical samples, also operating at pressure of 29 MPa but at 50 C. The operation time for the 85 C autoclave was 53 days (1272 hours) while that for the 50 C autoclave was 66 days (1584 hours). Debris were collected from the base of both autoclaves and analyzed by X-ray diffraction (XRD). Corrosion products were only found in the debris from the 85 C autoclave. The cement samples were analyzed before and after the exposure by X-ray florescence (XRF) methods. Optical microscopy was used to estimate an extent of the 316 stainless steel corrosion degradation.
Date: March 11, 2012
Creator: Ziomek-Moroz, M.; O’Connor, W. & Bullard, S.
System: The UNT Digital Library
Advanced Combustion (open access)

Advanced Combustion

The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).
Date: March 11, 2013
Creator: Holcomb, Gordon R.
System: The UNT Digital Library
Mask roughness induced LER control and mitigation: aberrations sensitivity study and alternate illumination scheme (open access)

Mask roughness induced LER control and mitigation: aberrations sensitivity study and alternate illumination scheme

Here we conduct a mask-roughness-induced line-edge-roughness (LER) aberrations sensitivity study both as a random distribution amongst the first 16 Fringe Zernikes (for overall aberration levels of 0.25, 0.50, and 0.75nm rms) as well as an individual aberrations sensitivity matrix over the first 37 Fringe Zernikes. Full 2D aerial image modeling for an imaging system with NA = 0.32 was done for both the 22-nm and 16-nm half-pitch nodes on a rough mask with a replicated surface roughness (RSR) of 100 pm and a correlation length of 32 nm at the nominal extreme-ultraviolet lithography (EUVL) wavelength of 13.5nm. As the ideal RSR value for commercialization of EUVL is 50 pm and under, and furthermore as has been shown elsewhere, a correlation length of 32 nm of roughness on the mask sits on the peak LER value for an NA = 0.32 imaging optic, these mask roughness values and consequently the aberration sensitivity study presented here, represent a worst-case scenario. The illumination conditions were chosen based on the possible candidates for the 22-nm and 16-nm half-pitch nodes, respectively. In the 22-nm case, a disk illumination setting of {sigma} = 0.50 was used, and for the 16-nm case, crosspole illumination with {sigma} = …
Date: March 11, 2011
Creator: McClinton, Brittany M. & Naulleau, Patrick P.
System: The UNT Digital Library
Probing the isothermal (delta)->(alpha)' martensitic transformation in Pu-Ga with in situ x-ray diffraction (open access)

Probing the isothermal (delta)->(alpha)' martensitic transformation in Pu-Ga with in situ x-ray diffraction

The time-temperature-transformation (TTT) curve for the {delta} {yields} {alpha}{prime} isothermal martensitic transformation in a Pu-1.9 at. % Ga alloy is peculiar because it is reported to have a double-C curve. Recent work suggests that an ambient temperature conditioning treatment enables the lower-C curve. However, the mechanisms responsible for the double-C are still not fully understood. When the {delta} {yields} {alpha}{prime} transformation is induced by pressure, an intermediate {gamma}{prime} phase is observed in some alloys. It has been suggested that transformation at upper-C temperatures may proceed via this intermediate phase, while lower-C transformation progresses directly from {delta} to {alpha}{prime}. To investigate the possibility of thermally induced transformation via the intermediate {gamma}{prime} phase, in situ x-ray diffraction at the Advanced Photon Source was performed. Using transmission x-ray diffraction, the {delta} {yields} {alpha}{prime} transformation was observed in samples as thin at 30 {micro}m as a function of time and temperature. The intermediate {gamma}{prime} phase was not observed at -120 C (upper-C curve) or -155 C (lower-C curve). Results indicate that the bulk of the {alpha}{prime} phase forms relatively rapidly at -120 C and -155 C.
Date: March 11, 2010
Creator: Jeffries, J. R.; Blobaum, K. M.; Schwartz, A. J.; Cynn, H.; Yang, W. & Evans, W. J.
System: The UNT Digital Library
Effects of Anisotropic Coherency Strains on Intercalation in Phase-Separating Crystals (open access)

Effects of Anisotropic Coherency Strains on Intercalation in Phase-Separating Crystals

None
Date: March 11, 2010
Creator: Stanton, L G & Bazant, M Z
System: The UNT Digital Library
NEAR INFRARED REFLECTANCE SPECTROSCOPY AS A PROCESS SIGNATURE IN URANIUM OXIDES (open access)

NEAR INFRARED REFLECTANCE SPECTROSCOPY AS A PROCESS SIGNATURE IN URANIUM OXIDES

None
Date: March 11, 2012
Creator: Plaue, J W; Klunder, G L; Czerwinski, K R & Hutcheon, I D
System: The UNT Digital Library
Replicated mask surface roughness effects on EUV lithographic pattering and line edge roughness (open access)

Replicated mask surface roughness effects on EUV lithographic pattering and line edge roughness

To quantify the roughness contributions to speckle, a programmed roughness substrate was fabricated with a number of areas having different roughness magnitudes. The substrate was then multilayer coated. Atomic force microscopy (AFM) surface maps were collected before and after multilayer deposition. At-wavelength reflectance and total integrated scattering measurements were also completed. Angle resolved scattering based power spectral densities are directly compared to the AFM based power spectra. We show that AFM overpredicts the roughness in the picometer measurements range. The mask was then imaged at-wavelength for the direct characterization of the aerial image speckle using the SEMATECH Berkeley Actinic Inspection Tool (AIT). Modeling was used to test the effectiveness of the different metrologies in predicting the measured aerial-image speckle. AIT measured contrast values are 25% or more than the calculated image contrast values obtained using the measured rms roughness input. The extent to which the various metrologies can be utilized for specifying tolerable roughness limits on EUV masks is still to be determined. Further modeling and measurements are being planned.
Date: March 11, 2011
Creator: George, Simi A.; Naulleau, Patrick P.; Gullikson, Eric M.; Mochi, Iacopo; Salmassi, Farhad; Goldberg, Kenneth A. et al.
System: The UNT Digital Library
22X mask cleaning effects on EUV lithography process and lifetime (open access)

22X mask cleaning effects on EUV lithography process and lifetime

For this paper, we evaluated the impact of repetitive cleans on a photomask that was fabricated and patterned for extreme ultraviolet lithography exposure. The lithographic performance of the cleaned mask, in terms of process window and line edge roughness, was monitored with the SEMATECH Berkeley micro-exposure tool (MET). Each process measurement of the cleaned mask was compared to a reference mask with the same mask architecture. Both masks were imaged on the same day in order to eliminate any process-related measurement uncertainties. The cleaned mask was periodically monitored with atomic force microscopy (AFM) measurements and pattern widths were monitored using scanning electron microscopy (SEM). In addition, reflectivity changes were also tracked with the aid of witness plate measurements. At the conclusion of this study, the mask under evaluation was cleaned 22 times; with none of the evaluation techniques showing any significant degradation in performance.
Date: March 11, 2011
Creator: George, Simi A.; Chen, Robert J.; Baclea-an, Lorie Mae & Naulleau, Patrick P.
System: The UNT Digital Library
Structural dynamics and ssDNA binding activity of the three N-terminal domains of the large subunit of Replication Protein A from small angle X-ray scattering (open access)

Structural dynamics and ssDNA binding activity of the three N-terminal domains of the large subunit of Replication Protein A from small angle X-ray scattering

Replication Protein A (RPA) is the primary eukaryotic ssDNA binding protein utilized in diverse DNA transactions in the cell. RPA is a heterotrimeric protein with seven globular domains connected by flexible linkers, which enable substantial inter-domain motion that is essential to its function. Small angle X-ray scattering (SAXS) experiments on two multi-domain constructs from the N-terminus of the large subunit (RPA70) were used to examine the structural dynamics of these domains and their response to the binding of ssDNA. The SAXS data combined with molecular dynamics simulations reveal substantial interdomain flexibility for both RPA70AB (the tandem high affinity ssDNA binding domains A and B connected by a 10-residue linker) and RPA70NAB (RPA70AB extended by a 70-residue linker to the RPA70N protein interaction domain). Binding of ssDNA to RPA70NAB reduces the interdomain flexibility between the A and B domains, but has no effect on RPA70N. These studies provide the first direct measurements of changes in orientation of these three RPA domains upon binding ssDNA. The results support a model in which RPA70N remains structurally independent of RPA70AB in the DNA bound state and therefore freely available to serve as a protein recruitment module.
Date: March 11, 2010
Creator: Pretto, Dalyir I.; Tsutakawa, Susan; Brosey, Chris A.; Castillo, Amalchi; Chagot, Marie-Eve; Smith, Jarrod A. et al.
System: The UNT Digital Library
Soft X-ray absorption spectra of aqueous salt solutions with highly charged cations in liquid microjets (open access)

Soft X-ray absorption spectra of aqueous salt solutions with highly charged cations in liquid microjets

X-ray absorption spectra of 1M aqueous solutions of indium (III) chloride, yttrium (III) bromide, lanthanum (III) chloride, tin (IV) chloride and chromium (III) chloride have been measured at the oxygen K-edge. Relatively minor changes are observed in the spectra compared to that of pure water. SnCl{sub 4} and CrCl{sub 3} exhibit a new onset feature which is attributed to formation of hydroxide or other complex molecules in the solution. At higher energy, only relatively minor, but salt-specific changes in the spectra occur. The small magnitude of the observed spectral changes is ascribed to offsetting perturbations by the cations and anions.
Date: March 11, 2010
Creator: Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; Drisdell, Walter S.; Smith, Jared D. & Saykally, Richard J.
System: The UNT Digital Library
Internal Energies of Ion-Sputtered Neutral Tryptophan and Thymine Molecules Determined by Vacuum Ultraviolet Photoionization (open access)

Internal Energies of Ion-Sputtered Neutral Tryptophan and Thymine Molecules Determined by Vacuum Ultraviolet Photoionization

Vacuum ultraviolet photoionization coupled to secondary neutral mass spectrometry (VUV-SNMS) of deposited tryptophan and thymine films are performed at the Chemical Dynamics Beamline. The resulting mass spectra show that while the intensity of the VUV-SNMS signal is lower than the corresponding secondary ion mass spectroscopy (SIMS) signal, the mass spectra are significantly simplified in VUV-SNMS. A detailed examination of tryptophan and thymine neutral molecules sputtered by 25 keV Bi3 + indicates that the ion-sputtered parent molecules have ~;;2.5 eV of internal energy. While this internal energy shifts the appearance energy of the photofragment ions for both tryptophan and thymine, it does not change the characteristic photoionizaton efficiency (PIE) curves of thymine versus photon energy. Further analysis of the mass spectral signals indicate that approximately 80 neutral thymine molecules and 400 tryptophan molecules are sputtered per incident Bi3 + ion. The simplified mass spectra and significant characteristic ion contributions to the VUV-SNMS spectra indicate the potential power of the technique for organic molecule surface analysis.
Date: March 11, 2010
Creator: Zhou, Jia; Takahashi, Lynelle; Wilson, Kevin R.; Leone, Stephen R. & Ahmed, Musahid
System: The UNT Digital Library
Out of band radiation effects on resist patterning (open access)

Out of band radiation effects on resist patterning

Our previous work estimated the expected out-of-band (OOB) flare contribution at the wafer level assuming that there is a given amount of OOB at the collector focus. We found that the OOB effects are wavelength, resist, and pattern dependent. In this paper, results from rigorous patterning evaluation of multiple OOB-exposed resists using the SEMATECH Berkeley 0.3-NA MET are presented. A controlled amount of OOB is applied to the resist films before patterning is completed with the MET. LER and process performance above the resolution limit and at the resolution limits are evaluated and presented. The results typically show a negative impact on LER and process performance after the OOB exposures except in the case of single resist formulation, where resolution and performance improvement was observed.
Date: March 11, 2011
Creator: George, Simi A . & Naulleau, Patrick P.
System: The UNT Digital Library
Absorber height effects on SWA restrictions and 'Shadow' LER (open access)

Absorber height effects on SWA restrictions and 'Shadow' LER

None
Date: March 11, 2011
Creator: McClinton, Brittany M.; Naulleau, Patrick P. & Wallow, Thomas
System: The UNT Digital Library
50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL (open access)

50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL

In support of X-band photoinjector development efforts at LLNL, a 50 MW test station is being constructed to investigate structure and photocathode optimization for future upgrades. A SLAC XL-4 klystron capable of generating 50 MW, 1.5 microsecond pulses will be the high power RF source for the system. Timing of the laser pulse on the photocathode with the applied RF field places very stringent requirements on phase jitter and drift. To achieve these requirements, the klystron will be powered by a state of the art, solid-state, high voltage modulator. The 50 MW will be divided between the photoinjector and a traveling wave accelerator section. A high power phase shifter is located between the photoinjector and accelerator section to adjust the phasing of the electron bunches with respect to the accelerating field. A variable attenuator is included on the input of the photoinjector. The distribution system including the various x-band components is being designed and constructed. In this paper, we will present the design, layout, and status of the RF system.
Date: March 11, 2011
Creator: Marsh, R A; Anderson, S G; Barty, C J; Beer, G K; Cross, R R; Ebbers, C A et al.
System: The UNT Digital Library
Net Hydrogenation of Pt-NHPh Bond Is Catalyzed by Elemental Pt (open access)

Net Hydrogenation of Pt-NHPh Bond Is Catalyzed by Elemental Pt

This article discusses the net hydrogenation of Pt-NHPh bond catalyzed by elemental Pt.
Date: March 11, 2010
Creator: Webb, Joanna R.; Pierpont, Aaron W.; Munro-Leighton, Colleen; Gunnoe, T. Brent; Cundari, Thomas R., 1964- & Boyle, Paul D.
System: The UNT Digital Library
Study of Ether-, Alcohol-, or Cyano-Functionalized Ionic Liquids Using Inverse Gas Chromatography (open access)

Study of Ether-, Alcohol-, or Cyano-Functionalized Ionic Liquids Using Inverse Gas Chromatography

This article discusses the study of ether-, alcohol, or cyano-functionalized ionic liquids using inverse gas chromatography.
Date: March 11, 2010
Creator: Revelli, Anne-Laure; Mutelet, Fabrice; Jaubert, Jean-Noël; Garcia-Martinez, Marina; Sprunger, Laura M.; Acree, William E. (William Eugene) et al.
System: The UNT Digital Library
Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident (open access)

Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident

Paper describes studying aiming to evaluate changes in pilot aircraft-assisted suicide risks, i.e., a copycat effect, in the U.S. and Germany after the Germanwings 2015 incident in the French Alps.
Date: March 11, 2018
Creator: Laukkala, Tanja; Vuorio, Alpo; Bor, Robert; Budowle, Bruce; Navathe, Pooshan; Pukkala, Eero et al.
System: The UNT Digital Library
Modified embedded atom method study of the mechanical properties of carbon nanotube reinforced nickel composites (open access)

Modified embedded atom method study of the mechanical properties of carbon nanotube reinforced nickel composites

Article on a modified embedded atom method study of the mechanical properties of carbon nanotube reinforced nickel composites.
Date: March 11, 2010
Creator: Uddin, Jamal; Baskes, Michael I.; Srivilliputhur, Srinivasan; Cundari, Thomas R., 1964- & Wilson, Angela K.
System: The UNT Digital Library
Social Reward Questionnaire (SRQ): development and validation (open access)

Social Reward Questionnaire (SRQ): development and validation

Article discusses study which led to the development of the Social Reward Questionnaire (SRQ), a measure of individual differences in the value of different social rewards.
Date: March 11, 2014
Creator: Foulkes, Lucy; Viding, Essi; McCrory, Eamon J. & Neumann, Craig S.
System: The UNT Digital Library
Composition of the Earth's Inner Core from High-pressure Sound Velocity Measurements in Fe-Ni-Si alloys (open access)

Composition of the Earth's Inner Core from High-pressure Sound Velocity Measurements in Fe-Ni-Si alloys

None
Date: March 11, 2010
Creator: Antonangeli, D.; Siebert, J.; Badro, J.; Farber, D. L.; Fiquet, G.; Morard, G. et al.
System: The UNT Digital Library