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Critical dimension sensitivity to post-exposure bake temperaturevariation in EUV photoresists

Description: Chemically amplified resists depend upon the post-exposure bake (PEB) process to drive the deprotection reactions (in positive resists) that lead to proper resist development. For this reason they often exhibit critical dimension (CD) sensitivity to PEB temperature variation. In this work the effects of variation in different aspects of the PEB step on post-develop CD are studied for two extreme ultraviolet (EUV) photoresists. The spatial and temporal temperature uniformity of the PEB plate is measured using a wireless sensor wafer. Programmed variations in the bake plate temperature set point are then used to measure the CD sensitivity to steady state temperature variation. In addition, the initial temperature ramp time is modified using a thin sheet of polyimide film between the wafer and the bake plate. This allows for measurement of the CD sensitivity to transient temperature variation. Finally, the bake time is adjusted to measure the CD sensitivity to this parameter.
Date: January 11, 2005
Creator: Cain, Jason P.; Naulleau, Patrick & Spanos, Costas J.
Partner: UNT Libraries Government Documents Department

Numerical studies of enthalpy and CO2 transients in two-phasewells

Description: Numerical studies of enthalpy and CO2 transients for wellscompleted in composite reservoir systems are carried out. Both constantrate and constant pressure production are considered. The results showthat relatively small variations in hydrologic parameters and vaporsaturation can have large effects on the enthalpy and CO2 content of theproduced fluids. Field data are presented that illustrate the theoreticalresults obtained.
Date: April 1, 1984
Creator: Bodvarsson, Gudmundur S.
Partner: UNT Libraries Government Documents Department

Measured strain in Nb3Sn coils during excitation and quence

Description: The strain in a high field Nb{sub 3}Sn coil was measured during magnet assembly, cool-down, excitation and spot heater quenches. Strain was measured with a full bridge strain gauge mounted directly over the turns and impregnated with the coil. Two such coils were placed in a 'common coil' fashion capable of reaching 11 T at 4.2 K. The measured steady state strain in the coil is compared with results obtained using the FEM code ANSYS. During quenches, the transient strain (due to temperature rise) was also measured and compared with the calculated mechanical time response to a quench.
Date: June 1, 2005
Creator: Caspi, S.; Barlett, S.E.; Dietderich, D. R.; Ferracin, P.; Gourlay, S. A.; Hannaford, C. R. et al.
Partner: UNT Libraries Government Documents Department


Description: Included in the conference proceedings are 69 papers grouped into the categories on the experimental and theoretical aspects of the scattering law,'' of spectra ln lattices and infinite media, and of transient and asymptotic phenomena. One paper in each of the categories is a summary of the material presented by the other papers in that group. Separate abstracts have been prepared for 52 papers, and 15 papers have been previously abstracted in NSA. (M.P.G.)
Date: October 31, 1963
Partner: UNT Libraries Government Documents Department

An analytical solution for transient radial flow through unsaturated fractured porous media

Description: This paper presents analytical solutions for one-dimensional radial transient flow through horizontal, unsaturated fractured rock formation. In these solutions, unsaturated flow through fractured media is described by a linearized Richards' equation, while fracture-matrix interaction is handled using the dual-continuum concept. Although linearizing Richards' equation requires a specially correlated relationship between relative permeability and capillary pressure functions for both fractures and matrix, these specially formed relative permeability and capillary pressure functions are still physically meaningful. These analytical solutions can thus be used to describe the transient behavior of unsaturated flow in fractured media under the described model conditions. They can also be useful in verifying numerical simulation results, which, as demonstrated in this paper, are otherwise difficult to validate.
Date: February 13, 2004
Creator: Wu, Yu-Shu & Pan, Lehua
Partner: UNT Libraries Government Documents Department

Analyses of coupled hydrological-mechanical effects during drilling of the FEBEX tunnel at Grimsel

Description: This paper presents analyses of coupled hydrological-mechanical (HM) processes during drilling of the FEBEX tunnel, located in fractured granite at Grimsel, Switzerland. Two and three-dimensional transient finite-element simulations were performed to investigate HM-induced fluid-pressure pulses, observed in the vicinity of the FEBEX tunnel during its excavation in 1995. The results show that fluid-pressure responses observed in the rock mass during TBM drilling of the FEBEX tunnel could not be captured using current estimates of regional stress. It was also shown that the measured pressure responses can be captured in both two and three-dimensional simulations if the stress field is rotated such that contraction (compressive strain rate) and corresponding increases in mean stress occur on the side of the drift, where increased fluid pressure spikes were observed.
Date: September 2, 2003
Creator: Rutqvist, J.; Rejeb, A.; Tijani, M. & Tsang, C.-F.
Partner: UNT Libraries Government Documents Department

Gas Releases During Saltcake Dissolution for Retrieval of Single-Shell Tank Waste

Description: It is possible to retrieve a large fraction of soluble waste from the Hanford single-shell waste tanks (SST) by dissolving it with water. This retrieval method will be demonstrated in U-107 and S-112 in the next few years. If saltcake dissolution proves practical and effective, many of the saltcake SSTs may be retrieved by this method. Many of the SSTs retain a large volume of flammable gas that will be released into the tank headspace as the waste dissolves. This report describes the physical processes that control dissolution and gas release. Calculation results are shown describing the headspace hydrogen concentration transient during dissolution. The observed spontaneous and induced gas releases from SSTs is summarized and the dissolution of the crust layer in SY-101 is discussed as a recent example of full-scale dissolution of saltcake containing a very large volume of retained gas. The report concludes that the dissolution rate is self limiting and gas release rates are relatively low.
Date: July 31, 2001
Creator: Stewart, Charles W
Partner: UNT Libraries Government Documents Department

Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

Description: This report describes a new initiative to strengthen the technical defensibility of predictions made with the Hanford site-wide groundwater flow and transport model. The focus is on characterizing major uncertainties in the current model. PNNL will develop and implement a calibration approach and methodology that can be used to evaluate alternative conceptual models of the Hanford aquifer system. The calibration process will involve a three-dimensional transient inverse calibration of each numerical model to historical observations of hydraulic and water quality impacts to the unconfined aquifer system from Hanford operations since the mid-1940s.
Date: May 2001
Creator: Cole, Charles R.; Bergeron, Marcel P.; Wurstner, Signe K.; Thorne, Paul D.; Orr, Samuel & Mckinley, Mathew I.
Partner: UNT Libraries Government Documents Department

Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996--Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer

Description: The baseline three-dimensional transient inverse model for the estimation of site-wide scale flow parameters, including their uncertainties, using data on the transient behavior of the unconfined aquifer system over the entire historical period of Hanford operations, has been modified to account for the effects of basalt intercommunication between the Hanford unconfined aquifer and the underlying upper basalt confined aquifer. Both the baseline and alternative conceptual models (ACM-1) considered only the groundwater flow component and corresponding observational data in the 3-Dl transient inverse calibration efforts. Subsequent efforts will examine both groundwater flow and transport. Comparisons of goodness of fit measures and parameter estimation results for the ACM-1 transient inverse calibrated model with those from previous site-wide groundwater modeling efforts illustrate that the new 3-D transient inverse model approach will strengthen the technical defensibility of the final model(s) and provide the ability to incorporate uncertainty in predictions related to both conceptual model and parameter uncertainty.
Date: August 29, 2001
Creator: Vermeul, Vince R; Cole, Charles R; Bergeron, Marcel P; Thorne, Paul D & Wurstner, Signe K
Partner: UNT Libraries Government Documents Department

A Multisensor system for the detection and characterization of UXOMM-0437

Description: A prototype active electromagnetic system has been developedfor detecting and characterizing UXO. The system employs two orthogonalvertical loop transmitters and a pair of horizontal loop transmittersspaced apart vertically by 0.7 m. Eight vertical field detectors aredeployed in the plane of each of the horizontal loops and are arranged tomeasure offset vertical gradients of the fields. The location andorientation of the three principal polarizabilities of a target can berecovered from a single position of the transmitter-receiver system.Further characterization of the target is obtained from the broadbandresponse. The system employs a bipolar half sine pulse train currentwaveform and the detectors are dB/dt induction coils designed to minimizethe transient response of the primary field pulse. The target transientis recovered in a 40 mu-sec to 1.0 msec window. The ground responseimposes an early time limit on the time window and system/ambient noiselimits the late time response. Nevertheless for practical transmittermoments and optimum receivers the size and the ratio of conductivity topermeability canbe accurately recovered. The prototype system hassuccessfully recovered the depths and polarizabilities of ellipsoidaltest targets.
Date: June 1, 2006
Creator: Gasperikova, Erika; Becker, A.; Morrison, H.F. & Smith, J.T.
Partner: UNT Libraries Government Documents Department


Description: Water hammer during multi-phase flow is rather complex, but in some cases an upper limit to the pressure surge magnitude during water hammer can be estimated. In the case considered here, a two mile long pipeline with a single high point was permitted to partially drain. Due to gravitational effects, air bubbles up through the pipe line to its highest point, but the time required for air to reach the top of the pipe is rather long. Consequently, some transients caused by valve operations are affected by air entrapment and some are not. The intent of this research was to investigate the complex interactions between air, water vapor, and liquid during water hammer in a long pipe with one end of the pipe open to atmospheric conditions. To understand the system dynamics, experimental data was obtained from a long pipeline with an open end and also from a short, transparent tube. Transient calculations were performed for valve closures and pump operations as applicable. The limitations of available calculation techniques were considered in detail.
Date: June 9, 2008
Creator: Leishear, R
Partner: UNT Libraries Government Documents Department

Hydrogen adsorption on Ru(001) studied by Scanning TunnelingMicroscopy

Description: The adsorption of hydrogen on Ru(001) was studied by scanning tunneling microscopy at temperatures around 50 K. Hydrogen was found to adsorb dissociatively forming different ordered structures as a function of coverage. In order of increasing coverage {theta} in monolayers (ML) these were ({radical}3 x {radical}3)r30{sup o} at {theta} = 0.3 ML; (2 x 1) at {theta} = 0.50 ML, (2 x 2)-3H at {theta} = 0.75, and (1 x 1) at {theta} = 1.00. Some of these structures were observed to coexist at intermediate coverage values. Close to saturation of 1 ML, H-vacancies (unoccupied three fold fcc hollow Ru sites) were observed either as single entities or forming transient aggregations. These vacancies diffuse and aggregate to form active sites for the dissociative adsorption of hydrogen.
Date: January 18, 2008
Creator: Tatarkhanov, Mous; Rose, Franck; Fomin, Evgeny; Ogletree, D.Frank & Salmeron, Miquel
Partner: UNT Libraries Government Documents Department

Ultrafast Enhancement of Ferromagnetism via Photoexcited Holes inGaMnAs

Description: We report on the observation of ultrafast photo-enhanced ferromagnetism in GaMnAs. It is manifested as a transient magnetization increase on a 100-ps time scale, after an initial sub-ps demagnetization. The dynamic magnetization enhancement exhibits a maximum below the Curie temperature {Tc} and dominates the demagnetization component when approaching {Tc}. We attribute the observed ultrafast collective ordering to the p-d exchange interaction between photoexcited holes and Mn spins, leading to a correlation-induced peak around 20K and a transient increase in {Tc}.
Date: February 17, 2007
Creator: Wang, J.; Cotoros, I.; Dani, K.M.; Liu, X.; Furdyna, J.K. & Chemla, D.S.
Partner: UNT Libraries Government Documents Department

Hydrogen Transport in Copper

Description: Hydrogen interaction with oxygen in copper exerts a significant influence on the apparent hydrogen diffusivity and the quantity of hydrogen absorbed. Correlation of the amount of absorbed tritium with oxygen content and dependence of permeation transients on both oxygen content and prior treatment indicate that both reversible and irreversible interactions occur between hydrogen and dissolved oxygen. This paper discusses results of that study.
Date: October 23, 2001
Creator: Caskey, G. R., Jr.
Partner: UNT Libraries Government Documents Department

Thermal, Electrical and Mechanical Response to a Quench in Nb3Sn Superconducting Coils

Description: During a quench, significant temperatures can arise as a magnet's stored energy is dissipated in the normal zone. Temperature gradients during this process give rise to localized strains within the coil. Reactive forces in the magnet structure balance the electromagnetic and thermal forces and maintain on equilibrium. In this paper we present a complete 3D finite element analysis of a racetrack coil. Specifically, the analysis focuses on thermal, electrical and mechanical conditions in a 10T Nb{sub 3}Sn coil built and tested as part of LBNL's Subscale Magnet Program. The study attempts to simulate time history of the temperature and voltage rise during quench propagation. The transient thermal stress after the quench is then evaluated and discussed.
Date: October 1, 2003
Creator: Ferracin, P.; Caspi, S.; Chiesa, L.; Gourlay, S.A.; Hafalia, R.r.; Imbasciati, L. et al.
Partner: UNT Libraries Government Documents Department

Development of Novel, Simple Multianalyte Sensors for Remote Environmental Analysis

Description: Advancement of our polymerized crystalline colloidal array chemical sensing technology. They have dramatically advanced their polymerized crystalline colloidal array chemical sensing technology. They fabricated nonselective sensors for determining pH and ionic strength. They also developed selective sensors for glucose and organophosphorus mimics of nerve gas agents. They developed a trace sensor for cations in water which utilized a novel crosslinking sensing motif. In all of these cases they have been able to theoretically model their sensor response by extending hydrogel volume phase transition theory. They also developed transient sampling methods to allow their ion sensing methods to operate at high ionic strengths. They also developed a novel optrode to provide for simple sampling.
Date: February 18, 2003
Creator: Asher, Sanford A.
Partner: UNT Libraries Government Documents Department

A Preliminary Low-Frequency Electromagnetic Analysis of a Flux Concentrator

Description: The objective of this investigation was to conduct a quick, preliminary transient magnetostatic analysis of a Brechna-type[1] flux concentrator to determine its feasibility for collecting positrons in the International Linear Collider. The magnetostatic transient module of Maxwell 3D, Version 10, from the Ansoft Corporation was used to model the flux concentrator.
Date: June 7, 2006
Creator: Mayhall, D J
Partner: UNT Libraries Government Documents Department