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The Omega-Loop Lid Domain of Phosphoenolpyruvate Carboxykinase is Essential for Catalytic Function
Abstract Not Provided
Stress and Strain Modeling of Low Temperature Cofired Ceramic (LTCC) Seal Frame and Lid.
Abstract not provided.
Stress and Strain Modeling of Low Temperature Cofired Ceramic (LTCC) Seal Frame and Lid.
Abstract not provided.
Gold-Tin Solder Wetting Behavior for Package Lid Seals: A Case Study.
Abstract not provided.
INSTRUMENTED LID FOR MONITORING SNF IN DRY STORAGE - 21281
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Enhancement of the sensitivity of the light-induced drift effect to interatomic interaction potentials using a mixture of two buffer gases
Based on five different nonempirical (calculated ab initio) interaction potentials for pairs of colliding Li – Ne particles and three different interaction potentials for pairs of colliding Li – Ar particles, we have theoretically investigated the spectral features of the light-induced drift (LID) rate of Li atoms in the buffer Ne gas in a mixture of buffer Ne + Ar gases. The calculations of LID of Li atoms in the buffer Ne gas for two interaction potentials predict anomalous LID and, as a result, strong sensitivity of the spectral shape of the LID lines to the differences in these potentials. For three other potentials (out of the five in question), the shape of the LID line of Li atoms in Ne is insensitive to the shape of the potential, since calculations with these potentials predict a normal LID effect. In this case, as it turned out, by adding a small fraction (approximately 10 %) of Ar to Ne, one can go from normal LID to anomalous LID and thereby radically increase the sensitivity of the LID line shape of Li atoms to the difference in these interaction potentials. The results obtained enable high-precision testing of the interatomic interaction potentials in experiments on anomalous LID. (nonlinear optical phenomena)
REGULATORY TESTING AND POSTTEST ANALYSIS OF THE DPP-3 TYPE B SHIPPING CONTAINER FOR NCT AND HAC TESTS
The safe transportation of radioactive material using appropriately designed and certified transportation packages is important to protect the public and environment. Therefore, a comprehensive and rigorous system of packaging requirements are required. The purpose of this test protocol is to determine the effects of drop testing on package performance in a Type B shipping package (DPP-3). Required physical tests for the DPP-3 package include normal conditions of transport and hypothetical accident conditions test requirements. The preparation, regulatory testing, and post-test evaluation of a Type B shipping package tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements will be presented. Six packages were tested and the responses when subjected to the HAC sequence of free drop, puncture, and thermal tests according to 10 CFR 71.73 were measured. The posttest helium leak test showed a leak rate less than 1 × 10-7 He-cc/sec which means that the containment boundary was maintained after the regulatory testing, therefore maintaining a leak tight environment. To determine the amount of change in the package performance measurements, statistical analyses were conducted using SPSS version 26. The null hypothesis of the testing was that there would not be a change in the measurements from pre to post-testing large enough to find statistical significance. Therefore, a finding of statistical significance indicated too much variability in the package design and was deemed an unfavorable finding. A repeated measures t-test was used to analyze the drum lids and CV torques. A one-way ANOVA was used to analyze height and diameter packages. Results of the repeated measures t-test indicated that all six containment vessel lid torques were statistically significant. However only three out of the six drum lid torques were statistically significant. Therefore, design of the lids caused more variability than necessary when subjected to the following drop tests: 1.) horizontal and cold; 2.) vertical lid down; and 3.) corner with lid up. Results of the one-way ANOVA analysis on height indicated that four out of the six CTUs were statistically significant. Thus, design of the CTUs caused more variability then necessary when subjected to the following drop tests: 1.) horizontal hot; 2.) horizontal cold; 3.) corner lid up; and 4.) corner lid down. Results of the one-way ANOVA analysis on diameter indicated that all six CTUs were statistically significant. Thus, design of the CTUs caused more variability then necessary when subjected to all of the tests. The DPP-3 design has been shown to be an acceptable design for the transport of radioactive materials. However, results of the statistical analysis reveal a possible improvement in package and test design to reduce variability in package performance measurement before and after testing.
Influence of defects on the femtosecond laser damage resistance of multilayer dielectric gratings
Multilayer dielectric (MLD) gratings with high diffraction efficiency and a high laser-induced damage (LID) threshold for pulse compressors are key to scaling the peak and average power of chirped pulse amplification lasers. However, surface defects introduced by manufacturing, storage, and handling processes can reduce the LID resistance of MLD gratings and impact the laser output. The underlying mechanisms of such defect-initiated LID remain unclear, especially in the femtosecond regime. In this Letter, we model dynamic processes in interactions of a 20-fs near-infrared (NIR) laser pulse and a MLD grating design in the presence of cylindrically symmetrical nodules and particle contaminants and cracks at the surface. Utilizing a dynamic model based on a 2D finite difference in time domain (FDTD) field solver coupled with photoionization, electron collision, and refractive index modification, we study the simulation results for the damage site distribution initiated by defects of various types and sizes and its impact on the LID threshold of the grating design.
Syracuse Univesity Test Report On Uptake Factor Resulting From A Dropped Storage Container - Phase II
Under certain circumstances, powder from an accidently dropped container can become airborne and inhaled by people nearby such as those who are moving the containers. The inhaled fine particles can deposit on respiratory tracts and lungs, causing asthma, lung cancer, and other acute respiratory illnesses and chronic symptoms. The objective of this study was to develop a standard procedure to measure the airborne concentrations of different size particles within the vicinity of a dropped container where a significant portion of the contained powder is ejected. Tungsten oxide (WO 3 ) was selected in this study to represent relatively heavy powders (7.16 g/cm 3 specific gravity for WO 3 ). A typical can with the outer dimensions of 4.25” diameter and 4.875” tall was used as the container. The powder was dropped in two different configurations: 1) contained within a can covered by a lid that has a 0.25” diameter hole, and 2) contained within a can without a lid. The packing volume of the powder was 51.4 in 3 (842.7 cm 3 ) and the target mass was 1936 g. The tests were carried out in a full-scale stainless steel environmental chamber with an interior volume of 852 ft 3 (24.1 m3). The chamber system includes an internal recirculation loop with a rectangular air diffuser and 10 variable frequency drive fans to provide a typical room air recirculation flow pattern. Two air filters were installed in the chamber air supply duct and return duct to achieve the required low background particle concentration. The initial chamber air conditions were set at 70°F (± 5°F) and 50% (± 10%) RH. A supporting frame and releasing device were designed and built to trigger consistently the dropping of the can. The particle sampling inlet was placed 5 ft above the floor and 6 inches laterally away from the can’s falling path. Concentrations of particles between 0.5 μm and 20 μm were recorded in units of mass and number of particles per unit volume. The data acquisition rate was once every 2 seconds during the first 2 hours. A test procedure was developed and verified. A total of thirty two drop tests were performed, eight in Phase I and twenty four in Phase II, covering variations in dropping height (8 ft or 4 ft from the floor), room air movement (0.25-0.30 m/s or 0.10-0.15 m/s near the ceiling), landing scenario (on a flat plate or a block), and lid condition (¼” lid hole or no lid). There were ten tests with flat plate and ¼” lid hole, ten tests with flat plate no lid and twelve tests with block no lid.
Convection in Icy Satellites: Implications for Habitability and Planetary Protection
Solid-state convection and endogenic resurfacing in the outer ice shells of the icy Galilean satellites (especially Europa) may contribute to the habitability of their internal oceans and to the detectability of any biospheres by spacecraft. If convection occurs in an ice I layer, fluid motions are confined beneath a thick stagnant lid of cold, immobile ice that is too stiff to participate in convection. The thickness of the stagnant lid varies from 30 to 50% of the total thickness of the ice shell, depending on the grain size of ice. Upward convective motions deliver approximately 10(exp 9) to 10(exp 13) kg yr(sup -1) of ice to the base of the stagnant lid, where resurfacing events driven by compositional or tidal effects (such as the formation of domes or ridges on Europa, or formation of grooved terrain on Ganymede) may deliver materials from the stagnant lid onto the surface. Conversely, downward convective motions deliver the same mass of ice from the base of the stagnant lid to the bottom of the satellites ice shells. Materials from the satellites surfaces may be delivered to their oceans by downward convective motions if material from the surface can reach the base of the stagnant lid during resurfacing events. Triggering convection from an initially conductive ice shell requires modest amplitude (a few to tens of kelvins) temperature anomalies to soften the ice to permit convection, which may require tidal heating. Therefore, tidal heating, compositional buoyancy, and solid-state convection in combination may be required to permit mass transport between the surfaces and oceans of icy satellites. Callisto and probably Ganymede have thick stagnant lids with geologically inactive surfaces today, so forward contamination of their surfaces is not a significant issue. Active convection and breaching of the stagnant lid is a possibility on Europa today, so is of relevance to planetary protection policy.
Self-sealing container for protecting air sensitive samples
A self-sealing container, used for transferring one or more air sensitive samples between vacuum systems, includes a housing with a cavity that holds the sample(s), and a lid disposed on top of the housing. The lid is configured to interface with the housing to form a seal over the cavity when the lid is closed. At least two flexure systems, each coupled to the housing and the lid, are disposed on opposing sides of the housing. The flexure systems apply forces to the lid that move the lid horizontally and vertically above the housing, into an open position. A pneumatic actuator, movably coupled to the housing and the lid, that is actuated by a change in ambient pressure. When actuated, it applies forces that move the lid horizontally and vertically to the closed position, in opposition to and in excess of the forces applied by the flexure systems.
Pattern bonded finned cold plate
An apparatus includes a fin pack of parallel plates that protrude from a base, a lid attachable to the fin pack opposite the base, and a brazing material painted onto the lid only in a plurality of wettable regions. The lid is positioned against the fin pack, opposite the base, with portions of the plurality of regions contacting edges of the parallel plates. The lid is brazed to the fin pack without intrusion of the brazing material between the parallel plates. This is accomplished by obtaining a lid to be attached to a fin pack of parallel plates that protrude from a base, painting the lid with the brazing material only in a plurality of wettable regions, positioning the lid against the fin pack, opposite the base, with portions of the plurality of regions contacting edges of the parallel plates, and brazing the lid to the fin pack.
Preliminary results of the on-demand vortex-generator experiments
This is a report on the continuation of our experimental investigations (Saddoughi 1994) of 'on-demand' vortex generators. Conventional vortex generators as found on aircraft wings are mainly for suppression of separation during the off-design conditions. In cruise they perform no useful function and exert a significant drag penalty. Therefore, replacement of fixed rectangular or delta-wing generators by devices that could be activated when needed would be of interest. Also in our previous report, we described one example of an 'on-demand' device, which was developed by Jacobson & Reynolds (1995) at Stanford University, suitable for manufacture by micro-electro-mechanical technology. This device consists of a surface cavity elongated in the stream direction and covered with a lid cantilevered at the upstream end. The lid, which is a metal sheet with a sheet of piezoelectric ceramic bonded to it, lies flush with the boundary. On application of a voltage the ceramic expands or contracts; however, adequate amplitude can be obtained only by running at the cantilever resonance frequency and applying amplitude modulation: for 2.5 mm x 20 mm cantilevered lids, they obtained maximum tip displacements of the order of 100 pm. Thus fluid is expelled from the cavity through the gap around the lid on the downstroke. They used an asymmetrical gap configuration and found that periodic emerging jets on the narrow side induced periodic longitudinal vorticity into the boundary layer. Their device was used to modify the inner layer of the boundary layer for skin-friction reduction. The same method could be implemented for the replacement of the conventional vortex generators; however, to promote mixing and suppress separation we needed to deposit longitudinal vortices into the outer layer of the boundary layer, which required a larger vortex generator than the device built by Jacobson & Reynolds. Our vortex generator was built with a mechanically-driven cantilevered lid with an adjustable frequency. The device was made about ten times the size of Jacobson & Reynolds', the shape or size of the cavity and lid (28 mm x 250 mm) could be easily changed. The cavity depth, the cantilever-tip displacement, and the maximum lid frequency were 20 mm, 10 mm, and 60 Hz respectively. Our vortex generator was mounted on a turntable so that its yaw angle could be changed. Finally, tests over a range of ratios of vortex generator size to boundary-layer thickness could be carried out simply by changing the streamwise location of the device.
Revealing the Mechanism of Light-Induced Degradation and Regeneration of p-type Cz-Si
The goal of this SIPS project was to develop advanced spectroscopic tools to explore boron- oxygen related defects in p-type Czochralski (Cz) monocrystalline Si (c-Si) to inform processing strategies to permanently suppress these defects and improve cell efficiency. Our work can be divided into three categories: (a) establishment of surface passivation and fast-firing protocols for light induced degradation (LID) and regeneration in p-Cz Si; (b) sample preparation and identification of spectral features for LID and hydrogen in c-Si with vibrational and electron spin resonance (ESR) spectroscopies; (c) demonstration of the interrelation between high-temperature thermal annealing, which breaks nuclei for oxygen precipitates in LID and regeneration. To our knowledge, this is the first study that has identified LID defects using ESR. The magnetic properties of the LID defects will be invaluable in validating the structure of the LID defects through atomistic simulations. The results generated from this project were disseminated through conference presentations and proceedings, and a peer reviewed publication. The tools developed in this project will be used to study other forms of degradation in c-Si including light and elevated-temperature induced degradation in p-type Cz Si and process induced degradation in n-type Cz Si.
Pipe Overpack Container Fire Testing: Phase II-B
The Pipe Overpack Container (POC) was developed at Rocky Flats to transport plutonium residues with higher levels of plutonium than standard transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) for disposal. In 1996 Sandia National Laboratories (SNL) conducted a series of tests to determine the degree of protection POCs provided during storage accident events. One of these tests exposed four of the POCs to a 30-minute engulfing pool fire. This test resulted in one of the POCs generating sufficient internal pressure to pop off its drum lid and expose the top of the pipe container (PC) to the fire environment. The initial contents of the POCs were inert materials that would not generate large internal pressure within the PC if heated. However, POCs are now being used to store combustible Transuranic (TRU) waste at Department of Energy (DOE) sites. At the request of DOE's Office of Environmental Management (EM) and National Nuclear Security Administration (NNSA), SNL started conducting a new series of fire tests in 2015 to examine whether PCs with combustibles would reach a temperature that could result in: (1) decomposition of inner contents and (2) subsequent generation of sufficient gas to cause the PC to over-pressurize and release its inner contents. In 2016, Phase II of the tests showed that POCs tested in a pool fire failed within 3 minutes of ignition with the POC lid ejecting. These POC lids were fitted with a NUCFIL-019DS filter and revealed that this specific filter did not relieve sufficient pressure to prevent lid ejection. In the Fall of 2017, Phase II-A was conducted to expose POCs to a 30-minute pool fire with similar configurations to those tested in Phase II, except that the POC lids were fitted with an UltraTech (UT) 9424S filter instead. That specific filter was chosen because of its design to help relieve internal pressure during the fire and thus prevent lid ejection. In Phase II-A, however, setups of two POCs stacked upon one another were never tested, which led to this phase of tests, Phase II-B. This report will describe the various tests conducted in Phase II-B, present results from these tests, and implications for the POCs based on the test results will be discussed.