Feasibility demonstration for electroplating ultra-thin polyimide film

The effect of electrodeposition variables on film thickness was investigated using a dilute polyimide solution as a bath into which aluminum (as foil or as a vapor deposited coating) was immersed. The electrodeposited film was dried for 2 hours at 93 C (primarily to remove solvent) and cured for 18 hours at 186 C. Infrared studies indicate that imide formation (curing) occurs at 149 C under vacuum. From a conceptual viewpoint, satisfactory film metallized on one side can be obtained by this method. The cured ultra thin polyimide film exhibits properties equivalent to those of commercial film, and the surface appearance of the strippable polyimide film compares favorably with that of a sample of commercial film of thicker gauge. The feasibility of manufacturing approximately one million sq m of ultra thin film capable of being joined to fabricate an 800 m by 9 800 m square from starting material 0.5 to 1 m wide for space erectable structures was demonstrated

Topological pressure of simultaneous level sets

Multifractal analysis studies level sets of asymptotically defined quantities in a topological dynamical system. We consider the topological pressure function on such level sets, relating it both to the pressure on the entire phase space and to a conditional variational principle. We use this to recover information on the topological entropy and Hausdorff dimension of the level sets. Our approach is thermodynamic in nature, requiring only existence and uniqueness of equilibrium states for a dense subspace of potential functions. Using an idea of Hofbauer, we obtain results for all continuous potentials by approximating them with functions from this subspace. This technique allows us to extend a number of previous multifractal results from the $C^{1+\epsilon}$ case to the $C^1$ case. We consider ergodic ratios $S_n \phi/S_n \psi$ where the function $\psi$ need not be uniformly positive, which lets us study dimension spectra for non-uniformly expanding maps. Our results also cover coarse spectra and level sets corresponding to more general limiting behaviour.Comment: 32 pages, minor changes based on referee's comment

Hydrostratigraphy, groundwater flow, and nitrate transport within the Abbotsford Sumas aquifer, Whatcom County, Washington

From April 1997 to January 1999, a water quality study in a four square mile area in northern Whatcom County was conducted by the Geology Department and the Institute for Watershed Studies at Western Washington University. As part of this study, this thesis focused on characterizing the hydrostratigraphy, groundwater flow directions and flow velocities and developing a groundwater model using MODFLOW and Boss GMS version 2.0 (GMS) to simulate groundwater flow and nitrate transport within this area. Monthly groundwater levels and water quality data were collected and analyzed from 21 domestic wells and one piezometer in the field and at Western Washington University’s Institute for Watershed Studies State Certified Laboratory. This thesis used data collected from April 1997 to August 1998 which was divided into six seasons. To characterize the hydrostratigraphy, five geologic cross sections were constructed from well logs in the study area using Autocad. Six geologic units were identified, which were grouped into two hydrostratigraphic units defined as the Sumas Aquifer and the Sumas Aquitard. The Sumas Aquifer in this area is an unconfined aquifer ranging in thickness from 180 feet in the northeast portion of the study area to 80 feet in the southeast portion of the study area. The Sumas Aquifer is a heterogeneous mixture of gravel and sand with some scattered silt and clay lenses and displays good hydraulic continuity. The average hydraulic conductivity for the Sumas Aquifer was determined to be 929 feet/day. The Sumas Aquitard is primarily a clay layer underlying the Sumas Aquifer interpreted as Bellingham glaciomarine drift. The Sumas Aquitard also consists of scattered lenses of clay and or silt interpreted as ice contact and lacustrine deposits. Water table contour maps were created using the computer program Surfer version 6.0 (Surfer) for each of the six seasons using seasonally averaged water level data. A separate water table contour map was generated using the results of a groundwater model simulation. Groundwater flow directions determined from both sets of water table contours showed an overall northwest to southeast trend with the exception of the northwest portion of the study area which showed a south to southwest trend shifting to a southeast trend in the southeast portion of the study area. Groundwater flow velocity determined from seasonal water table contour maps using Surfer was approximately 20.0 feet/day in the northwest to southeast direction. The approximate travel time from the international border to the southern end of the study area in the direction of groundwater flow determined using field data was 1.8 years. Groundwater flow velocity using the model simulation was approximately 25 feet/day. The approximate travel time from the international border to the southern end of the study area in the direction of groundwater flow using GMS was approximately 1.5 years. Groundwater levels varied from season to season with the largest average difference of 4.4 feet (throughout the study area) occurring between Spring 1997 and Fall 1997. The greatest variation in water level in any one well due to seasonal recharge was 7.8 feet between Spring 1997 and Fall 1998 at well 3. Well 1 was the only well having a correlation between rising water levels and elevated nitrates. Two dimensional nitrate contours were created for each of the six seasons using seasonally averaged monthly nitrate data. Two dimensional nitrate contours indicate that the highest concentrations were dovm-gradient from large dairies and fertilized crops within the study area. Water quality data and two-dimensional nitrate contours indicate that most of the contamination in the central portion of the study area is localized and likely coming from sources up-gradient of wells 9, 14, and 18. However, elevated nitrates in wells 5, 6, and 7 in the northeast portion of the study area are attributed to sources across the international border in Canada. A groundwater model was developed for the study area using MODFLOW and GMS. Three nitrate transport simulations were created using GMS and a transport model (MT3D). A 50 mg/L spike of nitrate was entered into the model domain at selected points for one day. The nitrate spikes created contaminant plumes which were contoured at the end of one year for scenarios one and three, and at the end of six months for scenario two. Comparing nitrate transport simulations with nitrate concentrations obtained in the field revealed correlations of elevated nitrates from known up-gradient loading sources. Nitrate transport simulations indicate that large nitrate concentrations in the north and south central portions of the study area are likely caused by local source loading rather than source loading in Canada (specifically wells 14, and 18). However, transport simulations also suggest that the relatively stable elevated nitrate concentrations in the northwest (specifically wells 1 and 2) and northeast (specifically wells 5 and 6) portions of the study area are likely caused from sources across the international border in Canada

Non-convulsive status epilepticus induced by tiagabine in a patient with pseudoseizure

Tiagabine, a novel GABA reuptake inhibitor, has been reported to induce non-convulsive status epilepticus (NCSE) in patients with epilepsy. We report a 27 year old female with history of pseudoseizure documented by video-EEG monitoring who presented confusion while on 56 mg per day of tiagabine. Electroencephalography showed generalized sharp and slow wave discharges, consistent with NCSE. The NCSE was terminated by lorazepam and did not recur after tiagabine was discontinued. This case report suggests that tiagabine may induce NCSE in patients without epilepsy

Cavitation-induced ignition of cryogenic hydrogen-oxygen fluids

The Challenger disaster and purposeful experiments with liquid hydrogen (H2) and oxygen (Ox) tanks demonstrated that cryogenic H2/Ox fluids always self-ignite in the process of their mixing. Here we propose a cavitation-induced self-ignition mechanism that may be realized under these conditions. In one possible scenario, self-ignition is caused by the strong shock waves generated by the collapse of pure Ox vapor bubble near the surface of the Ox liquid that may initiate detonation of the gaseous H2/Ox mixture adjacent to the gas-liquid interface. This effect is further enhanced by H2/Ox combustion inside the collapsing bubble in the presence of admixed H2 gas

Evaluation of Chemical Composition and Particle Size Gradation of Evaporation-Reducing, Monolayer-Forming Materials

Initial field testing began shortly after the arrival of materials in August, 1964. The field experiments were designed to evaluate the effects of the long-chain alcohol C20 and particle size gradation on the effectiveness of evaporation retardants when applied by aerial techniques. The materials which were tested at Utah Lake are listed below

Equipment and Techniques for Aerial Application of Evaporation-Reducing Monlayer-Forming Materials to Lakes and Reservoirs

The authors wish to express their gratitude and sincere appreciation to the many organizations and individual who assisted in this research effort. The U. S. Bureau of Reclamation has sponsored the investigation of aerial application equipment and techniques. U.S. Bureau of Reclamation personnel concerned with the evaporation reduction research program have b en most cooperative in supporting the efforts at Utah State University. The Reeder Flying Service has worked with Utah State University in the developn1 pilot of aerial application equipment since the inception of the project in 1961. Mr. Charles Reeder ha been very cooperative throughout the research program. Mr. Kenneth Jewkes, pilot and mechanic, ha aid d materially in the success of the equipment development. The efforts and interest displayed by Mr. Don Larson during flight and application test have been very much appreciated. The Commissioner of Utah Lake, Mr. David 1. Gardner, has assisted in the research efforts at Utah Lake. The effort of Mr. Dave Rowley, Price River Commissioner, and Mr. Francis Strange, caretaker at Scofield Reservoir, were very much appreciated. The continued cooperation of the Salmon River Canal Company, has aided in the success of the research program. Many of the staff at Utah State University have participated in the aerial application research effort . The initial developments by Mr. Glen Stringham of the spray equipment, and subsequent contributions of Mr. Earl Israel en in developing the powder dispensing unit are acknowledged. Professor Duane Chadwick and Mr. Don Griffin have undertaken the development of the radio altimeter. Me rs. Edwin Olsen, Derle Thorpe, and Eugene Israel. en have assisted during application tests. The illustration contained in this report, together with the cover design, were prepared by Mr. Joe England. The effort of Mr . C. W. Lauritzen, editor, and Miss Barbara South, secretary, have materially aided in the preparation of the report