Science.gov

Sample records for bumps precision extraction

  1. Procedures For Making Precision CH Bumps On Capsules

    SciTech Connect

    Letts, S; Fearon, E; Buckley, S; Klingmann, J; Cook, B

    2004-11-10

    Recently we were asked to produce target capsules with bumps on the surface. The bumps were to test the effects of fill tubes in future targets. The bumps desired were to be Gaussian in shape and from 60 to 40 {micro}m in diameter and from 1 to 6 {micro}m high. The capsules had a nominal diameter of 500 {micro}m. The approach we used was to align a precision aperture to the capsule and coat through the aperture onto the capsule surface using plasma polymer coating. The bumps were characterized using optical microscopy, Wyko interferometry, and AFM sphere mapping.

  2. NSRL Extraction Bump Control in the Booster

    SciTech Connect

    Brennan,L.

    2008-10-01

    Due to inadequacies in the user interface of the booster orbit control system, a number of new tools were developed. The first priority was an accurate calculation of the winding currents given specific displacements at each extraction septa. Next, the physical limits of the power supplies ({+-}600 amps) needed to be taken into account. In light of this limit, a system is developed that indicates to the user what the allowed values of one bump parameter are once the other two have been specified. Finally, techniques are developed to account for the orbit behavior once power supplies are requested to exceed their {+-}600 amp limit. This includes a recalculation of bump parameters and a calculation of the amplitude of the residuals. Following this, possible areas for further development are outlined. These techniques were computationally developed in Mathematica and tested in the Methodical Accelerator Design (MAD) program before they were implemented into the control system. At the end, a description of the implementation of these techniques in a new interface is described. This includes a depiction of the appearance and functionality of the graphical user interface, a description of the input and output flow, and an outline of how each important calculation is performed.

  3. Apparatus for Precise Indium-Bump Bonding of Microchips

    NASA Technical Reports Server (NTRS)

    Wild, Larry; Mulder, Jerry; Alvarado, Nicholas

    2005-01-01

    An improved apparatus has been designed and built for use in precise positioning and pressing of a microchip onto a substrate (which could, optionally, be another microchip) for the purpose of indium-bump bonding. The apparatus (see figure) includes the following: A stereomicroscope, A stage for precise positioning of the microchip in rotation angle (theta) about the nominally vertical pressing axis and in translation along two nominally horizontal coordinate axes (x and y), and An actuator system that causes a bonding tip to press the microchip against the substrate with a precisely controlled force. In operation, the microscope and the stage are used to position the microchip under the bonding tip and to align the indium bumps on the chip and the substrate, then the actuator system is used to apply a prescribed bonding force for a prescribed time. The improved apparatus supplants a partly similar prior apparatus that operated with less precision and repeatability, producing inconsistent and unreliable bonds. Results of the use of the prior apparatus included broken microchips, uneven bonds, and bonds characterized, variously, by overcompression or undercompression. In that apparatus, the bonding force was generated and controlled by use of a micrometer head positioned over the center of a spring-loaded scale, and the force was applied to the microchip via the scale, which was equipped for digital readout of the force. The inconsistency of results was attributed to the following causes: It was not possible to control the bonding force with sufficient precision or repeatability. Particularly troublesome was the inability to control the force at levels less than the weight of 150 g. Excessive compliance in the spring-loaded scale, combined with deviations from parallelarity of the substrate and bonding-tip surfaces, gave rise to nonuniformity in the pressure applied to the microchip, thereby generating excessive stresses and deformations in the microchip. In the

  4. The AGS New Fast Extracted Beam System orbit bump pulser

    SciTech Connect

    Chang, J.S.; Soukas, A.V.

    1993-01-01

    The AGS New Fast Extracted Beam System (New FEB) is designed for RHIC injection and the g-2 experiment, performing single bunch multiple extraction at the prf of 20 to 100 Hz up to 12 times per AGS cycle. Capacitor-discharge pulsers are required to produce local orbit bumps at the fast kicker and ejector magnet locations. These pulsers have to deliver half-sine current pulses at 1 KA peak with a base width of 5 msec. The discharge voltage will require approximately 800V with a [plus minus]0.1% accuracy. Direct charging will require a charger too costly and difficult to build because of the high prf. An alternative charging system is being developed to take advantage of the 1.5 sec idle time between each group of pulses. The charger power supply ratings and regulation requirements are thus greatly reduced. The system analysis and results from a prototype will be presented.

  5. The AGS New Fast Extracted Beam System orbit bump pulser

    SciTech Connect

    Chang, J.S.; Soukas, A.V.

    1993-06-01

    The AGS New Fast Extracted Beam System (New FEB) is designed for RHIC injection and the g-2 experiment, performing single bunch multiple extraction at the prf of 20 to 100 Hz up to 12 times per AGS cycle. Capacitor-discharge pulsers are required to produce local orbit bumps at the fast kicker and ejector magnet locations. These pulsers have to deliver half-sine current pulses at 1 KA peak with a base width of 5 msec. The discharge voltage will require approximately 800V with a {plus_minus}0.1% accuracy. Direct charging will require a charger too costly and difficult to build because of the high prf. An alternative charging system is being developed to take advantage of the 1.5 sec idle time between each group of pulses. The charger power supply ratings and regulation requirements are thus greatly reduced. The system analysis and results from a prototype will be presented.

  6. Orbit bump by DC magnets and halo collimation for the RCS extraction

    NASA Astrophysics Data System (ADS)

    Tang, J. Y.

    2007-06-01

    The beam loss during the single turn extraction from a Rapid Cycling Synchrotron (RCS) with high beam power is of important concern. The extraction kickers are usually designed to have exigent total strength to avoid the beam loss. This will increase the construction cost or reduce the kickers' availability during operation. This paper introduces a method employing DC bump magnets and beam collimation during the early acceleration stage in order to reduce the requirement to the extraction kickers and the beam loss at the extraction. The orbit bump at the extraction septum produced by small DC magnets will collapse during the acceleration, and this will lower the requirement of the orbit separation by the kickers. At the same time, the similar orbit bump at the transverse collimators will allow the beam cleaning in the early acceleration stage and result in much smaller beam emittance at the extraction. The combined effect gives the low beam loss extraction with significantly lower kicker strength. The different ways of applying the method in the China Spallation Neutron Source are also presented.

  7. Precision Photometry of Long Period Variable Stars: Flares and Bumps in the Night (Poster abstract)

    NASA Astrophysics Data System (ADS)

    Mais, D.

    2015-06-01

    (Abstract only) Mira variable stars are a broad class of stars, which encompass spectroscopic classes of type M, S, and C. These stars are closely related in terms of their long term variability, position on the Hertzsprung-Russell diagram their intermediate mass (from ~0.8 to ~8 solar mass) and the fact that class M evolves into the S and C type stars as certain stages of shell burning around the core proceeds. Recently, evidence has accumulated to suggest that Mira variables may go through flare up stages which result in brightening on the order of several tenths of a magnitude or more and may last hours to days in length. Very little is known about these events, indeed it is not clear that these events are real. In order to address the reality of these events, we established an automated acquisition/analysis of a group of 108 Mira variables in order to obtain the densest coverage of the periods to better constrain the potential flare-ups. Telescope control scripts were put in place along with real time analysis. This allowed for unattended acquisition of data on every clear night, all night long, in the V, R, and I photometric bands. In addition, during the course of the night multiple determinations are often obtained for a given star. The light curves of many of the program stars show a Cepheid-like bump phenomenon, however these appear on the ascending part of the light curve. In general, these bumps appear in longer period Mira's (>350 days). Bumps are not obvious or easily seen in VISUAL data records, although slope changes during rising phase are seen in some cases. So far, greater than 100,000 magnitude determinations have been obtained, many closely spaced in time. This should help to further constrain the potential occurrences of flare-up events.

  8. Weak bump quasars

    NASA Technical Reports Server (NTRS)

    Mcdowell, Jonathan C.; Elvis, Martin; Wilkes, Belinda J.; Willner, Steven P.; Oey, M. S.

    1989-01-01

    The recent emphasis on big bumps dominating the UV continuum of quasars has obscured the facts that bump properties vary widely and that there are objects in which no such component is evident. As part of a survey of quasar continuum spectra, a class of quasars is identified in which the optical-UV continuum big bump feature appears to be weak or absent, relative to both IR and X-ray. These weak bump quasars are otherwise normal objects and constitute a few percent of the quasar population.

  9. Precision of the CAESAR scan-extracted measurements.

    PubMed

    Robinette, Kathleen M; Daanen, Hein A M

    2006-05-01

    Three-dimensional (3D) body scanners are increasingly used to derive 1D body dimensions from 3D whole body scans for instance, as input for clothing grading systems to make made-to-measure clothing or for width and depth dimensions of a seated workstation. In this study, the precision of the scanner-derived 1D dimensions from the CAESAR survey, a multinational anthropometric survey, was investigated. Two combinations of scanning teams with 3D whole body scanners were compared, one called the US Team and the other the Dutch Team. Twenty subjects were measured three times by one scanner and one team, and three times by the other combination. The subjects were marked prior to scanning using small dots, and the linear distances between the dots were calculated after processing the scans. The mean absolute difference (MAD) of the repetitions was calculated and this was compared to reported acceptable errors in manual measurements from the US Army's ANSUR survey when similar measurements were available. In addition, the coefficient of variation (CV) was calculated for all measurements. The results indicate that the CAESAR scan-extracted measurements are highly reproducible; for most measures the MAD is less than 5mm. In addition, more than 93% of the MAD values for CAESAR are significantly smaller than the ANSUR survey acceptable errors. Therefore, it is concluded that the type of scan-extracted measures used in CAESAR are as good as or better than comparable manual measurements. Scan-extracted measurements that do not use markers or are not straight-line distances are not represented here and additional studies would be needed to verify their precision. PMID:16202970

  10. Weak bump quasars

    NASA Technical Reports Server (NTRS)

    Wilkes, B. J.; Mcdowell, J.

    1994-01-01

    Research into the optical, ultraviolet and infrared continuum emission from quasars and their host galaxies was carried out. The main results were the discovery of quasars with unusually weak infrared emission and the construction of a quantitative estimate of the dispersion in quasar continuum properties. One of the major uncertainties in the measurement of quasar continuum strength is the contribution to the continuum of the quasar host galaxy as a function of wavelength. Continuum templates were constructed for different types of host galaxy and individual estimates made of the decomposed quasar and host continua based on existing observations of the target quasars. The results are that host galaxy contamination is worse than previously suspected, and some apparent weak bump quasars are really normal quasars with strong host galaxies. However, the existence of true weak bump quasars such as PHL 909 was confirmed. The study of the link between the bump strength and other wavebands was continued by comparing with IRAS data. There is evidence that excess far infrared radiation is correlated with weaker ultraviolet bumps. This argues against an orientation effect and implies a probable link with the host galaxy environment, for instance the presence of a luminous starburst. However, the evidence still favors the idea that reddening is not important in those objects with ultraviolet weak bumps. The same work has led to the discovery of a class of infrared weak quasars. Pushing another part of the envelope of quasar continuum parameter space, the IR-weak quasars have implications for understanding the effects of reddening internal to the quasars, the reality of ultraviolet turnovers, and may allow further tests of the Phinney dust model for the IR continuum. They will also be important objects for studying the claimed IR to x-ray continuum correlation.

  11. New magic angle bumps and magic translation bumps

    SciTech Connect

    Seeman, J.

    1983-10-28

    SLC beams of opposite charge can be transversely deflected in the same direction by RF fields in the accelerating cavities caused by girder tilts, coupler-asymmetries, or manufacturing errors. A symmetric deflection can be corrected by a magic angle bump if the deflection is located adjacent to one of the linac quadrupoles. However, if the deflection is located between quadrupoles, two magic angle bumps or a magic angle bump and a magic translation bump are needed for the correction. Several examples of translation bumps are included. A new magic angle bump is also presented which is longitudinally compressed and has significantly reduced particle excursions. Finally, if new correctors are added midway along the girders so that the number of correctors are doubled, then the longitudinal extent and the maximum particle excursion of these new magic bumps can be further reduced.

  12. Optimization of Indium Bump Morphology for Improved Flip Chip Devices

    NASA Technical Reports Server (NTRS)

    Jones, Todd J.; Nikzad, Shouleh; Cunningham, Thomas J.; Blazejewski, Edward; Dickie, Matthew R.; Hoenk, Michael E.; Greer, Harold F.

    2011-01-01

    Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place.

  13. Study of bump bonding technology

    SciTech Connect

    Selcuk Cihangir et al.

    2003-10-17

    Pixel detectors proposed for the new generation of hadron collider experiments will use bump-bonding technology based on either indium or Pb/Sn solder to connect the front-end readout chips to the silicon pixel sensors. We have previously reported large-scale tests of the yield using both indium and Pb/Sn solder bump [1]. The conclusion is that both seem to be viable for pixel detectors. We have also carried out studies of various effects (e.g. storage over long period, effect of heating and cooling, and radiation) on both types of bump bonds using daisy-chained parts on a small scale [2], [3]. Overall, these tests showed little changes in the integrity of the bump connections. Nevertheless, questions still remain on the long-term reliability of the bumps due to thermal cycle effects, attachment to a substrate with a different coefficient of thermal expansion (CTE), and radiation.

  14. The bumps on the hippocampus

    NASA Astrophysics Data System (ADS)

    Gao, Yi; Ver Hoef, Lawrence

    2016-03-01

    The hippocampus has been the focus of more imaging research than any other subcortical structure in the human brain. However a feature that has been almost universally overlooked are the bumpy ridges on the inferior aspect of the hippocampus, which we refer to as hippocampal dentation. These bumps arise from folds in the CA1 layer of Ammon's horn. Similar to the folding of the cerebral cortex, hippocampal dentation allows for greater surface area in a confined space. However, while quantitative studies of radiologic brain images have been advancing for decades, examining numerous approaches to hippocampal segmentation and morphology analysis, virtually all published 3D renderings of the hippocampus show the under surface to be quite smooth or mildly irregular; we have rarely seen the characteristic bumpy structure in the reconstructed 3D scene, one exception being the 9.4T postmortem study. This is presumably due to the fact that, based on our experience with high resolution images, there is a dramatic degree of variability in hippocampal dentation between individuals from very smooth to highly dentated. An apparent question is, does this indicate that this specific morphological signature can only be captured using expensive ultra-high field techniques? Or, is such information buried in the data we commonly acquire, awaiting a computation technique that can extract and render it clearly? In this study, we propose a super-resolution technique that captures the fine scale morphometric features of the hippocampus based on common T1-weighted 3T MR images.

  15. Beam Based Calibration of Slow Orbit Bump in the NSLS Booster

    SciTech Connect

    Yang, X.; Shaftan, T.; Rose, J.

    2009-05-04

    The orbit bumps in NSLS booster are used to move the beam orbit within 2mm of the extraction septum aperture on a time scale of millisecond at extraction in order to reduce the requirement on the amplitude of the fast extraction kicker. This may cause charge losses since before extraction, the beam stays on the distorted orbit for thousands of revolutions. In order to find the optimal orbit bump setpoint, which brings the maximum distortion at the extraction position and minimum distortions everywhere else, we developed an extraction model and performed an experiment to validate it. Afterwards, the model was applied to optimize the extraction process.

  16. Precision and Selection of Extraction Methods of Aphelenchid Nematodes from Maritime Pine Wood, Pinus pinaster L.

    PubMed

    Penas, Ana C; Diias, Luis S; Mota, Manuel M

    2002-03-01

    Four extraction methods for Bursaphelenchus xylophilus and other aphelenchid nematodes were compared on the number of nematodes per gram recovered, and on the precision of the mean number of nematodes per gram of pine wood. The number of nematodes per gram recovered by each method, in addition to its inherent shortcomings when the actual number of nematodes is unknown, failed to provide clear rankings among the extraction methods. The precision of the mean number of nematodes per gram did provide clear guidelines for selection. Selection of the method may be based on prior knowledge about the range of nematodes to be expected or the independence of precision from the mean number of nematodes. PMID:19265909

  17. Shadows for bump-mapped surfaces

    SciTech Connect

    Max, N.L.

    1985-11-05

    Bump mapping produces realistic shading by perturbing normal vectors to a surface, but does not show the shadows that the bumps cast on nearby parts of the same surface. In this paper, these shadows are found from precomputed tables of horizon angles, listing, for each position entry, the elevation of the horizon in a sampled collection of directions. These tables are made for bumps on a standard flat surface, and then a transformation is developed so that the same tables can be used for an arbitrary curved parameterized surface patch. This necessitates a new method for scaling the bump size to the patch size. 7 refs., 8 figs.

  18. Computer tomography-based precision inspection and shape extraction using facet model

    NASA Astrophysics Data System (ADS)

    Wang, Wenjian; Wu, Xiaogu; Wee, William G.

    2000-01-01

    We apply the facet mode to extract edge and surface information from computed tomography (CT) images for precision inspection and shape extraction. First we explore the application of the facet model in a 3D filter design. A 3D directional-derivative-based surface detector is developed to extract surface points from the CT images. Subpixel accuracy is achieved by locating the zeros of the 3D second directional derivative along the estimated gradient direction. Then we develop a precision inspection system to take turbine blade wall width measurements from CT images and compare them to the corresponding optical measurements. Least mean squares methods are used to enhance prediction accuracy with the adaptive property of increasing accuracy when additional variable data are available. The system accuracy is within 3 mil. Unverified measurements are adjusted based on the verified measurements, and experiments show increasing accuracy of the adjusted measurements as additional verified measurements are available. Also, quantitative analysis of a trapezoid-shaped workpiece is performed. The results indicate that the CT system performance is affected by the structure and size of a workpiece. We also present an algorithm to extract 3D shapes from detected surface points interactively and use them for visual inspection.

  19. Condensation on Slippery Asymmetric Bumps

    NASA Astrophysics Data System (ADS)

    Park, Kyoo-Chul; Kim, Philseok; Aizenberg, Joanna

    Controlling dropwise condensation by designing surfaces that enable droplets to grow rapidly and be shed as quickly as possible is fundamental to water harvesting systems, thermal power generation, distillation towers, etc. However, cutting-edge approaches based on micro/nanoscale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach based on principles derived from Namib desert beetles, cacti, and pitcher plants that synergistically couples both aspects of condensation and outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bump geometry in promoting condensation, we show how to maximize vapor diffusion flux at the apex of convex millimetric bumps by optimizing curvature and shape. Integrating this apex geometry with a widening slope analogous to cactus spines couples rapid drop growth with fast directional transport, by creating a free energy profile that drives the drop down the slope. This coupling is further enhanced by a slippery, pitcher plant-inspired coating that facilitates feedback between coalescence-driven growth and capillary-driven motion. We further observe an unprecedented six-fold higher exponent in growth rate and much faster shedding time compared to other surfaces. We envision that our fundamental understanding and rational design strategy can be applied to a wide range of phase change applications.

  20. Process for Patterning Indium for Bump Bonding

    NASA Technical Reports Server (NTRS)

    Denis, Kevin

    2012-01-01

    An innovation was created for the Cosmology Large Angular Scale Surveyor for integration of low-temperature detector chips with a silicon backshort and a silicon photonic choke through flipchip bonding. Indium bumps are typically patterned using liftoff processes, which require thick resist. In some applications, it is necessary to locate the bumps close to high-aspect-ratio structures such as wafer through-holes. In those cases, liftoff processes are challenging, and require complicated and time-consuming spray coating technology if the high-aspect-ratio structures are delineated prior to the indium bump process. Alternatively, processing the indium bumps first is limited by compatibility of the indium with subsequent processing. The present invention allows for locating bumps arbitrarily close to multiple-level high-aspect-ratio structures, and for indium bumps to be formed without liftoff resist. The process uses the poor step coverage of indium deposited on a silicon wafer that has been previously etched to delineate the location of the indium bumps. The silicon pattern can be processed through standard lithography prior to adding the high-aspect-ratio structures. Typically, high-aspectratio structures require a thick resist layer so this layer can easily cover the silicon topography. For multiple levels of topography, the silicon can be easily conformally coated through standard processes. A blanket layer of indium is then deposited onto the full wafer; bump bonding only occurs at the high points of the topography.

  1. Smooth transitions between bump rendering algorithms

    SciTech Connect

    Becker, B.G. Max, N.L. |

    1993-01-04

    A method is described for switching smoothly between rendering algorithms as required by the amount of visible surface detail. The result will be more realism with less computation for displaying objects whose surface detail can be described by one or more bump maps. The three rendering algorithms considered are bidirectional reflection distribution function (BRDF), bump-mapping, and displacement-mapping. The bump-mapping has been modified to make it consistent with the other two. For a given viewpoint, one of these algorithms will show a better trade-off between quality, computation time, and aliasing than the other two. Thus, it needs to be determined for any given viewpoint which regions of the object(s) will be rendered with each algorithm The decision as to which algorithm is appropriate is a function of distance, viewing angle, and the frequency of bumps in the bump map.

  2. Condensation on slippery asymmetric bumps.

    PubMed

    Park, Kyoo-Chul; Kim, Philseok; Grinthal, Alison; He, Neil; Fox, David; Weaver, James C; Aizenberg, Joanna

    2016-03-01

    Controlling dropwise condensation is fundamental to water-harvesting systems, desalination, thermal power generation, air conditioning, distillation towers, and numerous other applications. For any of these, it is essential to design surfaces that enable droplets to grow rapidly and to be shed as quickly as possible. However, approaches based on microscale, nanoscale or molecular-scale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach--based on principles derived from Namib desert beetles, cacti, and pitcher plants--that synergistically combines these aspects of condensation and substantially outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bumpy surface geometry in promoting condensation, and using theoretical modelling, we show how to maximize vapour diffusion fluxat the apex of convex millimetric bumps by optimizing the radius of curvature and cross-sectional shape. Integrating this apex geometry with a widening slope, analogous to cactus spines, directly couples facilitated droplet growth with fast directional transport, by creating a free-energy profile that drives the droplet down the slope before its growth rate can decrease. This coupling is further enhanced by a slippery, pitcher-plant-inspired nanocoating that facilitates feedback between coalescence-driven growth and capillary-driven motion on the way down. Bumps that are rationally designed to integrate these mechanisms are able to grow and transport large droplets even against gravity and overcome the effect of an unfavourable temperature gradient. We further observe an unprecedented sixfold-higher exponent of growth rate, faster onset, higher steady-state turnover rate, and a greater volume of water collected compared to other surfaces. We envision that this fundamental understanding and rational design strategy can be

  3. Condensation on slippery asymmetric bumps

    NASA Astrophysics Data System (ADS)

    Park, Kyoo-Chul; Kim, Philseok; Grinthal, Alison; He, Neil; Fox, David; Weaver, James C.; Aizenberg, Joanna

    2016-03-01

    Controlling dropwise condensation is fundamental to water-harvesting systems, desalination, thermal power generation, air conditioning, distillation towers, and numerous other applications. For any of these, it is essential to design surfaces that enable droplets to grow rapidly and to be shed as quickly as possible. However, approaches based on microscale, nanoscale or molecular-scale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach—based on principles derived from Namib desert beetles, cacti, and pitcher plants—that synergistically combines these aspects of condensation and substantially outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle’s bumpy surface geometry in promoting condensation, and using theoretical modelling, we show how to maximize vapour diffusion fluxat the apex of convex millimetric bumps by optimizing the radius of curvature and cross-sectional shape. Integrating this apex geometry with a widening slope, analogous to cactus spines, directly couples facilitated droplet growth with fast directional transport, by creating a free-energy profile that drives the droplet down the slope before its growth rate can decrease. This coupling is further enhanced by a slippery, pitcher-plant-inspired nanocoating that facilitates feedback between coalescence-driven growth and capillary-driven motion on the way down. Bumps that are rationally designed to integrate these mechanisms are able to grow and transport large droplets even against gravity and overcome the effect of an unfavourable temperature gradient. We further observe an unprecedented sixfold-higher exponent of growth rate, faster onset, higher steady-state turnover rate, and a greater volume of water collected compared to other surfaces. We envision that this fundamental understanding and rational design strategy can be

  4. HIGH-PRECISION BIOLOGICAL EVENT EXTRACTION: EFFECTS OF SYSTEM AND OF DATA

    PubMed Central

    Cohen, K. Bretonnel; Verspoor, Karin; Johnson, Helen L.; Roeder, Chris; Ogren, Philip V.; Baumgartner, William A.; White, Elizabeth; Tipney, Hannah; Hunter, Lawrence

    2013-01-01

    We approached the problems of event detection, argument identification, and negation and speculation detection in the BioNLP’09 information extraction challenge through concept recognition and analysis. Our methodology involved using the OpenDMAP semantic parser with manually written rules. The original OpenDMAP system was updated for this challenge with a broad ontology defined for the events of interest, new linguistic patterns for those events, and specialized coordination handling. We achieved state-of-the-art precision for two of the three tasks, scoring the highest of 24 teams at precision of 71.81 on Task 1 and the highest of 6 teams at precision of 70.97 on Task 2. We provide a detailed analysis of the training data and show that a number of trigger words were ambiguous as to event type, even when their arguments are constrained by semantic class. The data is also shown to have a number of missing annotations. Analysis of a sampling of the comparatively small number of false positives returned by our system shows that major causes of this type of error were failing to recognize second themes in two-theme events, failing to recognize events when they were the arguments to other events, failure to recognize nontheme arguments, and sentence segmentation errors. We show that specifically handling coordination had a small but important impact on the overall performance of the system. The OpenDMAP system and the rule set are available at http://bionlp.sourceforge.net. PMID:25937701

  5. Bumps in Small-World Networks

    PubMed Central

    Laing, Carlo R.

    2016-01-01

    We consider a network of coupled excitatory and inhibitory theta neurons which is capable of supporting stable spatially-localized “bump” solutions. We randomly add long-range and simultaneously remove short-range connections within the network to form a small-world network and investigate the effects of this rewiring on the existence and stability of the bump solution. We consider two limits in which continuum equations can be derived; bump solutions are fixed points of these equations. We can thus use standard numerical bifurcation analysis to determine the stability of these bumps and to follow them as parameters (such as rewiring probabilities) are varied. We find that under some rewiring schemes bumps are quite robust, whereas in other schemes they can become unstable via Hopf bifurcation or even be destroyed in saddle-node bifurcations. PMID:27378897

  6. Protective effects of aged garlic extract against bromobenzene toxicity to precision cut rat liver slices.

    PubMed

    Wang, B H; Zuzel, K A; Rahman, K; Billington, D

    1998-04-01

    Precision-cut liver slices from phenobarbital-treated rats were incubated for up to 8 h with the industrial solvent and hepatotoxin bromobenzene at a final concentration of 1 mM. Phenobarbital pretreatment potentiates bromobenzene hepatotoxicity by inducing those P450 isoforms responsible for the formation of the active hepatotoxin, namely bromobenzene-3,4-oxide. A reduction in cell viability was indicated by a decrease in the K+, ATP and glutathione content of the slices and the increased release of the intracellular enzymes, lactate dehydrogenase and alanine aminotransferase, into the medium. Furthermore, levels of lipid peroxidation as judged by the formation of thiobarbituric acid reactive substances, were increased approximately 5-fold. Aged garlic extract (AGE) at concentrations of 1-5% (v/v) reduced the toxicity of bromobenzene in a concentration-dependent manner as judged by all of the parameters of viability studied, with the exception of lipid peroxidation which was reduced to control levels even at the lowest concentration of garlic extract used. AGE was found to cause partial inhibition of cytochrome P450 when assayed as both 7-ethoxycoumarin O-deethylase and 7-pentoxyresorufin O-depentylase activities, but even the highest concentration used inhibited both activities by less than 50%. It is suggested that the hepatoprotective effects of AGE are due primarily to the reduced glutathione-sparing properties of its constituents, most probably its organosulphur compounds. PMID:9674969

  7. The 3000 A bump in quasars

    NASA Technical Reports Server (NTRS)

    Oke, J. B.; Shields, G. A.; Korycansky, D. G.

    1984-01-01

    New observations of the 3000 A bump in quasars are presented and some simple considerations regarding its physical origin are addressed. Absolute spectrophotometry of 30 quasars with redshifts between 0.53 and 0.70 was obtained with the multichannel spectrometer on the 5 m Hale telescope with a rest wavelength coverage of 2000-5000 A. The continuum observations are well represented by a single power law plus a smooth, broad bump and superposed Fe II multiplets. The strength of the bump correlates fairly well with that of H-beta but poorly with those of the Mg II and Fe II lines. Models consisting of a power law and optically thick hydrogen continua with temperatures of about 12,000 K, and Balmer-edge optical depths equal to three fit the observed energy distributions well. The physical conditions and continuum emission of a dense slab of hydrogen heated by gamma rays are analyzed.

  8. Rapid and simple UPLC-MS/MS method for precise phytochelatin quantification in alga extracts.

    PubMed

    Bräutigam, Anja; Wesenberg, Dirk; Preud'homme, Hugues; Schaumlöffel, Dirk

    2010-09-01

    Quantitative phytochelatin (PC) analysis is, due to oxidation sensitivity of the PCs, matrix effects, and time consuming sample preparation, still a challenging analytical task. In this study, a rapid, simple, and sensitive method for precise determination of native PCs in crude extracts of the green alga Chlamydomonas reinhardtii was developed. Algae were exposed 48 h to 70 μM Cd. Coupling of ultra performance liquid chromatography and electrospray ionization tandem mass spectrometry with multi-reaction mode transitions for detection permitted the required short-time, high-resolution separation and detection specificity. Thus, under optimized chromatographic conditions, 10 thiol peptides were baseline-separated within 7 min. Relative detection limits in the nanomolar range in microliter sample volumes were achieved (corresponding to absolute detection limits at femtomole level). Next to glutathione (GSH), the most abundant cadmium-induced PCs in C. reinhardtii, namely CysGSH, PC(2), PC(3), CysPC(2), and CysPC(3), were quantified with high reproducibility at concentrations between 15 and 198 nmol g(-1) fresh weight. The biological variation of PC synthesis of nine independently grown alga cultures was determined to be on average 13.7%. PMID:20632163

  9. The chorionic bump: Etiologic insights from two pathologic pregnancies.

    PubMed

    Wax, Joseph R; Blaszyk, Hagen; Jones, Michael; Cartin, Angelina; Pinette, Michael G

    2016-09-01

    The clinical significance and etiology of the chorionic bump remain unclear. We describe two pregnancies characterized by chorionic bumps, which subsequently were diagnosed with a complete mole and trisomy 18, respectively. We hypothesize that placental pathology, including edema and hydropic villi, may contribute to or cause the sonographic finding of some chorionic bumps. An association between chorionic bumps and aneuploidy awaits future study. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:452-454, 2016. PMID:27220064

  10. Good Teaching: The Goose Bump Response.

    ERIC Educational Resources Information Center

    Ricciotti, Joseph A.

    1988-01-01

    Teachers who can trigger the "goose bump" response have probably mastered the fine art of teaching. Such teachers are enthusiastic, excited about their subject matter, and genuinely care about their students. When "artistic" teachers manifest glaring teaching deficiencies, the sensitive principal overlooks these flaws or handles them without…

  11. Adapting bump model for ventral photoreceptors of Limulus

    PubMed Central

    1982-01-01

    Light-evoked current fluctuations have been recorded from ventral photoreceptors of Limulus for light intensity from threshold up to 10(5) times threshold. These data are analyzed in terms of the adapting bump noise model, which postulates that (a) the response to light is a summation of bumps; and (b) the average size of bump decreases with light intensity, and this is the major mechanism of light adaptation. It is shown here that this model can account for the data well. Furthermore, the model provides a convenient framework to characterize, in terms of bump parameters, the effects of calcium ions, which are known to affect photoreceptor functions. From responses to very dim light, it is found that the average impulse response (average of a large number of responses to dim flashes) can be predicted from knowledge of both the noise characteristics under steady light and the dispersion of latencies of individual bumps. Over the range of light intensities studied, it is shown that (a) the bump rate increases in strict proportionality to light intensity, up to approximately 10(5) bumps per second; and (b) the bump height decreases approximately as the -0.7 power of light intensity; at rates greater than 10(5) bumps per second, the conductance change associated with the single bump seems to reach a minimum value of approximately 10(-11) reciprocal ohms; (c) from the lowest to the highest light intensity, the bump duration decreases approximately by a factor of 2, and the time scale of the dispersion of latencies of individual bumps decreases approximately by a factor of 3; (d) removal of calcium ions from the bath lengthens the latency process and causes an increase in bump height but appears to have no effect on either the bump rate or the bump duration. PMID:7108487

  12. Electrodeposition of Indium Bumps for Ultrafine Pitch Interconnection

    NASA Astrophysics Data System (ADS)

    Tian, Yingtao; Liu, Changqing; Hutt, David; Stevens, Bob

    2014-02-01

    Electroplating is a promising method to produce ultrafine pitch indium bumps for assembly of pixel detectors in imaging applications. In this work, the process of indium bumping through electrodeposition was demonstrated and the influences of various current waveforms on the bump morphology, microstructure and height uniformity were investigated. Electron microscopy was used to study the microstructure of electroplated indium bumps and a Zygo white light interferometer was utilised to evaluate the height uniformity. The results indicated that the bump uniformities on wafer, pattern and feature scales were improved by using unipolar pulse and bipolar pulse reverse current waveforms.

  13. THE ACS LCID PROJECT. IV. DETECTION OF THE RED GIANT BRANCH BUMP IN ISOLATED GALAXIES OF THE LOCAL GROUP

    SciTech Connect

    Monelli, M.; Hidalgo, S. L; Aparicio, A.; Gallart, C.; Cassisi, S.; Bernard, E. J.; Skillman, E. D. E-mail: carme@iac.e E-mail: shidalgo@iac.e E-mail: ejb@roe.ac.u

    2010-08-01

    We report the detection and analysis of the red giant branch (RGB) luminosity function bump in a sample of isolated dwarf galaxies in the Local Group. We have designed a new analysis approach comparing the observed color-magnitude diagrams (CMDs) with theoretical best-fit CMDs derived from precise estimates of the star formation histories of each galaxy. This analysis is based on studying the difference between the V magnitude of the RGB bump and the horizontal branch at the level of the RR Lyrae instability strip ({Delta}V {sup bump}{sub HB}) and we discuss here a technique for reliably measuring this quantity in complex stellar systems. By using this approach, we find that the difference between the observed and predicted values of {Delta}V {sup bump}{sub HB} is +0.13 {+-} 0.14 mag. This is smaller, by about a factor of 2, than the well-known discrepancy between theory and observation at low metallicity commonly derived for Galactic globular clusters (GCs). This result is confirmed by a comparison between the adopted theoretical framework and empirical estimates of the {Delta}V {sup bump}{sub HB} parameter for both a large database of Galactic GCs and for four other dwarf spheroidal galaxies for which this estimate is available in the literature. We also investigate the strength of the RGB bump feature (R{sub bump}), and find very good agreement between the observed and theoretically predicted R{sub bump} values. This agreement supports the reliability of the evolutionary lifetimes predicted by theoretical models of the evolution of low-mass stars.

  14. A precise study on effects that trigger alkaline hemicellulose extraction efficiency.

    PubMed

    Hutterer, Christian; Schild, Gabriele; Potthast, Antje

    2016-08-01

    The conversion of paper-grade pulps into dissolving pulps requires efficient strategies and process steps to remove low-molecular noncellulosic macromolecules generally known as hemicelluloses. Current strategies include alkaline extractions and enzymatic treatments. This study focused on the evaluation of extraction efficiencies in alkaline extractions of three economically interesting hardwood species: beech (Fagus sylvatica), birch (Betula papyrifera), and eucalyptus (Eucalyptus globulus). Substrate pulps were subjected to alkaline treatments at different temperatures and alkalinities using white liquor as the alkali source, followed by analyses of both pulps and hemicellulose-containing extraction lyes. The extracted hardwood xylans have strong potential as an ingredient in the food and pharmaceutical industries. Subsequent analyses revealed strong dependencies of the extraction efficiencies and molar mass distributions of hemicelluloses on the process variables of temperature and effective alkalinity. The hemicellulose content of the initial pulps, the hardwood species, and the type of applied base played minor roles. PMID:27163434

  15. Argument-predicate distance as a filter for enhancing precision in extracting predications on the genetic etiology of disease

    PubMed Central

    Masseroli, Marco; Kilicoglu, Halil; Lang, François-Michel; Rindflesch, Thomas C

    2006-01-01

    Background Genomic functional information is valuable for biomedical research. However, such information frequently needs to be extracted from the scientific literature and structured in order to be exploited by automatic systems. Natural language processing is increasingly used for this purpose although it inherently involves errors. A postprocessing strategy that selects relations most likely to be correct is proposed and evaluated on the output of SemGen, a system that extracts semantic predications on the etiology of genetic diseases. Based on the number of intervening phrases between an argument and its predicate, we defined a heuristic strategy to filter the extracted semantic relations according to their likelihood of being correct. We also applied this strategy to relations identified with co-occurrence processing. Finally, we exploited postprocessed SemGen predications to investigate the genetic basis of Parkinson's disease. Results The filtering procedure for increased precision is based on the intuition that arguments which occur close to their predicate are easier to identify than those at a distance. For example, if gene-gene relations are filtered for arguments at a distance of 1 phrase from the predicate, precision increases from 41.95% (baseline) to 70.75%. Since this proximity filtering is based on syntactic structure, applying it to the results of co-occurrence processing is useful, but not as effective as when applied to the output of natural language processing. In an effort to exploit SemGen predications on the etiology of disease after increasing precision with postprocessing, a gene list was derived from extracted information enhanced with postprocessing filtering and was automatically annotated with GFINDer, a Web application that dynamically retrieves functional and phenotypic information from structured biomolecular resources. Two of the genes in this list are likely relevant to Parkinson's disease but are not associated with this disease

  16. Electroplated indium bump arrays and the bonding reliability

    NASA Astrophysics Data System (ADS)

    Qiuping, Huang; Gaowei, Xu; Gang, Quan; Yuan, Yuan; Le, Luo

    2010-11-01

    A novel electroplating indium bumping process is described, as a result of which indium bump arrays with a pitch of 100 μm and a diameter of 40 μm were successfully prepared. UBM (under bump metallization) for indium bumping was investigated with an XRD technique. The experimental results indicate that Ti/Pt (300 Å / 200 Å) has an excellent barrier effect both at room temperature and at 200 °C. The bonding reliability of the indium bumps was evaluated by a shear test. Results show that the shear strength of the indium bump significantly increases after the first reflow and then changes slowly with increasing reflow times. Such a phenomenon may be caused by the change in textures of the indium after reflow. The corresponding flip-chip process is also discussed in this paper.

  17. Enantioselective Liquid-Solid Extraction (ELSE)--An Unexplored, Fast, and Precise Analytical Method.

    PubMed

    Ulatowski, Filip; Hamankiewicz, Paulina; Jurczak, Janusz

    2015-09-14

    A novel method of evaluating the enantioselectivity of chiral receptors is investigated. It involves extraction of an ionic guest in racemic form from an ion-exchange resin to the organic solvent, where it is bound by a chiral receptor. The enantioselectivity of the examined receptor is determined simply by measuring the enantiomeric excess of the extracted guest. We show that the concept is viable for neutral receptors binding chiral organic anions extracted into acetonitile. This method was determined to be more accurate and far less time-consuming than the classical titrations. Multiple racemic guests can be applied to a resin in a single experiment, giving the method a very high throughput. PMID:26263300

  18. A novel method for direct solder bump pull testing using lead-free solders

    NASA Astrophysics Data System (ADS)

    Turner, Gregory Alan

    This thesis focuses on the design, fabrication, and evaluation of a new method for testing the adhesion strength of lead-free solders, named the Isotraction Bump Pull method (IBP). In order to develop a direct solder joint-strength testing method that did not require customization for different solder types, bump sizes, specific equipment, or trial-and-error, a combination of two widely used and accepted standards was created. First, solder bumps were made from three types of lead free solder were generated on untreated copper PCB substrates using an in-house fabricated solder bump-on-demand generator, Following this, the newly developed method made use of a polymer epoxy to encapsulate the solder bumps that could then be tested under tension using a high precision universal vertical load machine. The tests produced repeatable and predictable results for each of the three alloys tested that were in agreement with the relative behavior of the same alloys using other testing methods in the literature. The median peak stress at failure for the three solders tested were 2020.52 psi, 940.57 psi, and 2781.0 psi, and were within one standard deviation of the of all data collected for each solder. The assumptions in this work that brittle fracture occurred through the Intermetallic Compound layer (IMC) were validated with the use of Energy-Dispersive X-Ray Spectrometry and high magnification of the fractured surface of both newly exposed sides of the test specimens. Following this, an examination of the process to apply the results from the tensile tests into standard material science equations for the fracture of the systems was performed..

  19. Cascading reminiscence bumps in popular music.

    PubMed

    Krumhansl, Carol Lynne; Zupnick, Justin Adam

    2013-10-01

    Autobiographical memories are disproportionately recalled for events in late adolescence and early adulthood, a phenomenon called the reminiscence bump. Previous studies on music have found autobiographical memories and life-long preferences for music from this period. In the present study, we probed young adults' personal memories associated with top hits over 5-and-a-half decades, as well as the context of their memories and their recognition of, preference for, quality judgments of, and emotional reactions to that music. All these measures showed the typical increase for music released during the two decades of their lives. Unexpectedly, we found that the same measures peaked for the music of participants' parents' generation. This finding points to the impact of music in childhood and suggests that these results reflect the prevalence of music in the home environment. An earlier peak occurred for 1960s music, which may be explained by its quality or by its transmission through two generations. We refer to this pattern of musical cultural transmission over generations as cascading reminiscence bumps. PMID:24006129

  20. On the accuracy and precision of numerical waveforms: effect of waveform extraction methodology

    NASA Astrophysics Data System (ADS)

    Chu, Tony; Fong, Heather; Kumar, Prayush; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilagyi, Bela

    2016-08-01

    We present a new set of 95 numerical relativity simulations of non-precessing binary black holes (BBHs). The simulations sample comprehensively both black-hole spins up to spin magnitude of 0.9, and cover mass ratios 1–3. The simulations cover on average 24 inspiral orbits, plus merger and ringdown, with low initial orbital eccentricities e\\lt {10}-4. A subset of the simulations extends the coverage of non-spinning BBHs up to mass ratio q = 10. Gravitational waveforms at asymptotic infinity are computed with two independent techniques: extrapolation and Cauchy characteristic extraction. An error analysis based on noise-weighted inner products is performed. We find that numerical truncation error, error due to gravitational wave extraction, and errors due to the Fourier transformation of signals with finite length of the numerical waveforms are of similar magnitude, with gravitational wave extraction errors dominating at noise-weighted mismatches of ∼ 3× {10}-4. This set of waveforms will serve to validate and improve aligned-spin waveform models for gravitational wave science.

  1. Towards Evidence-based Precision Medicine: Extracting Population Information from Biomedical Text using Binary Classifiers and Syntactic Patterns

    PubMed Central

    Raja, Kalpana; Dasot, Naman; Goyal, Pawan; Jonnalagadda, Siddhartha R

    2016-01-01

    Precision Medicine is an emerging approach for prevention and treatment of disease that considers individual variability in genes, environment, and lifestyle for each person. The dissemination of individualized evidence by automatically identifying population information in literature is a key for evidence-based precision medicine at the point-of-care. We propose a hybrid approach using natural language processing techniques to automatically extract the population information from biomedical literature. Our approach first implements a binary classifier to classify sentences with or without population information. A rule-based system based on syntactic-tree regular expressions is then applied to sentences containing population information to extract the population named entities. The proposed two-stage approach achieved an F-score of 0.81 using a MaxEnt classifier and the rule- based system, and an F-score of 0.87 using a Nai've-Bayes classifier and the rule-based system, and performed relatively well compared to many existing systems. The system and evaluation dataset is being released as open source. PMID:27570671

  2. Towards Evidence-based Precision Medicine: Extracting Population Information from Biomedical Text using Binary Classifiers and Syntactic Patterns.

    PubMed

    Raja, Kalpana; Dasot, Naman; Goyal, Pawan; Jonnalagadda, Siddhartha R

    2016-01-01

    Precision Medicine is an emerging approach for prevention and treatment of disease that considers individual variability in genes, environment, and lifestyle for each person. The dissemination of individualized evidence by automatically identifying population information in literature is a key for evidence-based precision medicine at the point-of-care. We propose a hybrid approach using natural language processing techniques to automatically extract the population information from biomedical literature. Our approach first implements a binary classifier to classify sentences with or without population information. A rule-based system based on syntactic-tree regular expressions is then applied to sentences containing population information to extract the population named entities. The proposed two-stage approach achieved an F-score of 0.81 using a MaxEnt classifier and the rule- based system, and an F-score of 0.87 using a Nai've-Bayes classifier and the rule-based system, and performed relatively well compared to many existing systems. The system and evaluation dataset is being released as open source. PMID:27570671

  3. The Physics of Bump Drafting in Car Racing

    ERIC Educational Resources Information Center

    Fiolhais, Miguel C. N.; Amor dos Santos, Susana

    2014-01-01

    The technique of bump drafting, also known as two-car drafting in motorsports, is analysed in the framework of Newtonian mechanics and simple aerodynamic drag forces. As an apparent unnatural effect that often pleases the enthusiasts of car racing, bump drafting provides a unique pedagogical opportunity for students to gain insights into the…

  4. Tank Bump Accident Potential and Consequences During Waste Retrieval

    SciTech Connect

    BRATZEL, D.R.

    2000-09-27

    This report provides an evaluation of Hanford tank bump accident potential and consequences during waste retrieval operations. The purpose of this report is to consider the best available new information to support recommendations for safety controls. A new tank bump accident analysis for safe storage (Epstein et al. 2000) is extended for this purpose. A tank bump is a postulated event in which gases, consisting mostly of water vapor, are suddenly emitted from the waste and cause tank headspace pressurization. Tank bump scenarios, physical models, and frequency and consequence methods are fully described in Epstein et al. (2000). The analysis scope is waste retrieval from double-shell tanks (DSTs) including operation of equipment such as mixer pumps and air lift circulators. The analysis considers physical mechanisms for tank bump to formulate criteria for bump potential during retrieval, application of the criteria to the DSTs, evaluation of bump frequency, and consequence analysis of a bump. The result of the consequence analysis is the mass of waste released from tanks; radiological dose is calculated using standard methods (Cowley et al. 2000).

  5. Two-Step Plasma Process for Cleaning Indium Bonding Bumps

    NASA Technical Reports Server (NTRS)

    Greer, Harold F.; Vasquez, Richard P.; Jones, Todd J.; Hoenk, Michael E.; Dickie, Matthew R.; Nikzad, Shouleh

    2009-01-01

    A two-step plasma process has been developed as a means of removing surface oxide layers from indium bumps used in flip-chip hybridization (bump bonding) of integrated circuits. The two-step plasma process makes it possible to remove surface indium oxide, without incurring the adverse effects of the acid etching process.

  6. Bumping into Someone: Japanese Students' Perceptions and Observations

    ERIC Educational Resources Information Center

    Lieske, Carmella

    2010-01-01

    This pilot study explores the apologies Japanese nursing college students thought they would use in their L1 (i.e. Japanese) and their L2 (i.e. English) when bumping into each other. The students completed a questionnaire, the results of which indicated that they believed they should always apologize for bumping into someone. The paper describes…

  7. Bump Bonding Using Metal-Coated Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Lamb, James L.; Dickie, Matthew R.; Kowalczyk, Robert S.; Liao, Anna; Bronikowski, Michael J.

    2012-01-01

    Bump bonding hybridization techniques use arrays of indium bumps to electrically and mechanically join two chips together. Surface-tension issues limit bump sizes to roughly as wide as they are high. Pitches are limited to 50 microns with bumps only 8-14 microns high on each wafer. A new process uses oriented carbon nanotubes (CNTs) with a metal (indium) in a wicking process using capillary actions to increase the aspect ratio and pitch density of the connections for bump bonding hybridizations. It merges the properties of the CNTs and the metal bumps, providing enhanced material performance parameters. By merging the bumps with narrow and long CNTs oriented in the vertical direction, higher aspect ratios can be obtained if the metal can be made to wick. Possible aspect ratios increase from 1:1 to 20:1 for most applications, and to 100:1 for some applications. Possible pitch density increases of a factor of 10 are possible. Standard capillary theory would not normally allow indium or most other metals to be drawn into the oriented CNTs, because they are non-wetting. However, capillary action can be induced through the ability to fabricate oriented CNT bundles to desired spacings, and the use of deposition techniques and temperature to control the size and mobility of the liquid metal streams and associated reservoirs. This hybridization of two technologies (indium bumps and CNTs) may also provide for some additional benefits such as improved thermal management and possible current density increases.

  8. Are weak bump quasars edge-on sources?

    NASA Astrophysics Data System (ADS)

    Wang, Tinggui; Cheng, Fuhua; Zhou, Youyuan

    1993-01-01

    The "big bump" is one of the most striking features of the spectral energy distribution of quasars. However, McDowell et al. revealed a few quasars with a weak bump or without a bump when they studied the broad-band energy distribution (100 μm to 4 keV) of 31 quasars. By excluding the possibilities of reddening and contamination of starlight, they argued that these objects are intrinsic weak bump quasars, but they did not give any explanation. Motivated by why these objects are different from others, the authors of this paper have studied their UV spectra. Their results suggest that the weak bump quasars may be edge-on sources.

  9. Extracting Accurate and Precise Topography from Lroc Narrow Angle Camera Stereo Observations

    NASA Astrophysics Data System (ADS)

    Henriksen, M. R.; Manheim, M. R.; Speyerer, E. J.; Robinson, M. S.; LROC Team

    2016-06-01

    The Lunar Reconnaissance Orbiter Camera (LROC) includes two identical Narrow Angle Cameras (NAC) that acquire meter scale imaging. Stereo observations are acquired by imaging from two or more orbits, including at least one off-nadir slew. Digital terrain models (DTMs) generated from the stereo observations are controlled to Lunar Orbiter Laser Altimeter (LOLA) elevation profiles. With current processing methods, digital terrain models (DTM) have absolute accuracies commensurate than the uncertainties of the LOLA profiles (~10 m horizontally and ~1 m vertically) and relative horizontal and vertical precisions better than the pixel scale of the DTMs (2 to 5 m). The NAC stereo pairs and derived DTMs represent an invaluable tool for science and exploration purposes. We computed slope statistics from 81 highland and 31 mare DTMs across a range of baselines. Overlapping DTMs of single stereo sets were also combined to form larger area DTM mosaics, enabling detailed characterization of large geomorphic features and providing a key resource for future exploration planning. Currently, two percent of the lunar surface is imaged in NAC stereo and continued acquisition of stereo observations will serve to strengthen our knowledge of the Moon and geologic processes that occur on all the terrestrial planets.

  10. Modeling interseismic deformation field of North Tehran Fault extracted from precise leveling observation

    NASA Astrophysics Data System (ADS)

    Amighpey, Masoome; Voosoghi, Behzad; Arabi, Siyavash

    2016-06-01

    The North Tehran Fault (NTF) stands out as a major active thrust fault running for approximately 110 km north of Tehran, the capital province of Iran. It has been the source of several major historical earthquakes in the past, including those in 958, 1665, and 1830. In this paper, interseismic strain accumulation on the NFT was investigated using precise leveling measurements obtained over the time frame 1997-2005. The relationship between surface deformation field and interseismic deformation models was evaluated using simulated annealing optimization in a Bayesian framework. The results show that the NTF fault follows an elastic dislocation model creep at a rate of 2.5 ± 0.06 mm/year in the eastern part and 6.2 ± 0.04 mm/year in the western part. Moreover, the locking depth of the fault was evaluated to be ± 1.1 km in the eastern part and 1.3 ± 0.2 km in the western part.

  11. Review of research into shock control bumps

    NASA Astrophysics Data System (ADS)

    Bruce, P. J. K.; Colliss, S. P.

    2015-09-01

    This paper presents a review of research on shock control bumps (SCBs), a class of flow control device with potential for application to transonic wings. Beginning with a brief review of the origins of the SCB concept, the primary focus is on the more recent studies from the last decade. Results from both experimental and numerical work are considered and the synergy between these two approaches to SCB research is critically explored. It is shown that the aerodynamic performance enhancement potential of SCBs, namely their capacity for drag reduction and delaying the onset of buffet for transonic wings, has been widely demonstrated in the literature, as has the high sensitivity of SCB performance to flow conditions including shock strength and position, and post-shock adverse pressure gradient. These characteristic features of SCBs are relatively well explained in terms of the flow physics that have been observed for different bump geometries. This stems from a number of studies that have focused on the balance of viscous and inviscid flow features and also the mechanism by which finite span SCBs generate streamwise vorticity. It is concluded that our understanding of SCBs is reaching an advanced level of maturity for SCBs in simple configurations and steady flow fields. However, SCB performance in unsteady flow and on swept wings requires further investigation before the concept can be considered a viable candidate for transonic wings. These investigations should adopt a multi-disciplinary approach combining carefully designed experiments and targeted computations. Finally, two concepts for future SCB research are suggested: the adaptive SCB and SCBs in engine intakes.

  12. Optimizing galvanic pulse plating parameters to improve indium bump to bump bonding

    NASA Astrophysics Data System (ADS)

    Coleman, Jonathan J.; Rowen, Adam; Mani, Seethambal S.; Yelton, W. Graham; Arrington, Christian; Gillen, Rusty; Hollowell, Andrew E.; Okerlund, Daniel; Ionescu, Adrian

    2010-02-01

    The plating characteristics of a commercially available indium plating solution are examined and optimized to help meet the increasing performance demands of integrated circuits requiring substantial numbers of electrical interconnections over large areas. Current fabrication techniques rely on evaporation of soft metals, such as indium, into lift-off resist profiles. This becomes increasingly difficult to accomplish as pitches decrease and aspect ratios increase. To minimize pixel dimensions and maximize the number of pixels per unit area, lithography and electrochemical deposition (ECD) of indium has been investigated. Pulse ECD offers the capability of improving large area uniformity ideal for large area device hybridization. Electrochemical experimentation into lithographically patterned molds allow for large areas of bumps to be fabricated for low temperature indium to indium bonds. The galvanic pulse profile, in conjunction with the bath configuration, determines the uniformity of the plated array. This pulse is manipulated to produce optimal properties for hybridizing arrays of aligned and bonded indium bumps. The physical properties of the indium bump arrays are examined using a white light interferometer, a SEM and tensile pull testing. This paper provides details from the electroplating processes as well as conclusions leading to optimized plating conditions.

  13. Height inspection of wafer bumps without explicit 3D reconstruction

    NASA Astrophysics Data System (ADS)

    Dong, Mei; Chung, Ronald; Zhao, Yang; Lam, Edmund Y.

    2006-02-01

    The shrunk dimension of electronic devices leads to more stringent requirement on process control and quality assurance of their fabrication. For instance, direct die-to-die bonding requires placement of solder bumps not on PCB but on the wafer itself. Such wafer solder bumps, which are much miniaturized from the counterparts on PCB, still need to have their heights meet the specification, or else the electrical connection could be compromised, or the dies be crushed, or even the manufacturing equipments be damaged. Yet the tiny size, typically tens of microns in diameter, and the textureless and mirror nature of the bumps pose great challenge to the 3D inspection process. This paper addresses how a large number of such wafer bumps could have their heights massively checked against the specification. We assume ball bumps in this work. We propose a novel inspection measure about the collection of bump heights that possesses these advantages: (1) it is sensitive to global and local disturbances to the bump heights, thus serving the bump height inspection purpose; (2) it is invariant to how individual bumps are locally displaced against one another on the substrate surface, thus enduring 2D displacement error in soldering the bumps onto the wafer substrate; and (3) it is largely invariant to how the wafer itself is globally positioned relative to the imaging system, thus having tolerance to repeatability error in wafer placement. This measure makes use of the mirror nature of the bumps, which used to cause difficulty in traditional inspection methods, to capture images of two planes. One contains the bump peaks and the other corresponds to the substrate. With the homography matrices of these two planes and fundamental matrix of the camera, we synthesize a matrix called Biplanar Disparity Matrix. This matrix can summarize the bumps' heights in a fast and direct way without going through explicit 3D reconstruction. We also present a design of the imaging and

  14. QCD Precision Measurements and Structure Function Extraction at a High Statistics, High Energy Neutrino Scattering Experiment: NuSOnG

    SciTech Connect

    Adams, T.; Batra, P.; Bugel, Leonard G.; Camilleri, Leslie Loris; Conrad, Janet Marie; de Gouvea, A.; Fisher, Peter H.; Formaggio, Joseph Angelo; Jenkins, J.; Karagiorgi, Georgia S.; Kobilarcik, T.R.; /Fermilab /Texas U.

    2009-06-01

    We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of 'Beyond the Standard Model' physics.

  15. Accuracy and precision of cap thickness in small incision lenticule extraction

    PubMed Central

    Ozgurhan, Engin Bilge; Agca, Alper; Bozkurt, Ercument; Gencer, Baran; Celik, Ugur; Cankaya, Kadir Ilker; Demirok, Ahmet; Yilmaz, Omer Faruk

    2013-01-01

    Aims To report and compare the cap thickness predictability of small incision lenticule extraction (SMILE) and flap thickness of femtosecond laser-assisted in situ keratomileusis (femto-LASIK). Settings and design Beyoglu Eye Training and Research Hospital, Refractive Surgery Department, Istanbul, Turkey. Retrospective pilot study. Materials and methods Medical records of patients who had SMILE in one eye and femto-LASIK in the other eye were reviewed. Visante corneal Optical Coherence Tomography (OCT) images at 1 week and 1 month post-surgery were analyzed. Both cap and flap thickness at the temporal edge and the nasal edge were measured and compared to each other. Statistical analyses used PAWS Statistics 18 and unpaired student t-test were used to compare the groups. Results The study included 66 eyes of 33 patients (24.7 ± 3.8 years, 20 females and 13 males). Mean flap thickness was 114.88 μm ± 4.96 μm, and mean cap thickness was 114.63 μm ± 5.18 μm. In group 1 (SMILE), cap thickness values were 115.84 μm ± 6.84 μm, 114.75 μm ± 7.36 μm, 113.66 μm ± 6.88 μm, and 114.27 μm ± 6.90 μm in measurement zones 1, 2, 3, and 4, respectively. In group 2 (FemtoLASIK), flap corneal thickness values were 115.96 mmHg ± 7.01 mmHg, 114.72 mmHg ± 7.17 mmHg, 113.54 mmHg ± 6.45 mmHg, and 115.30 mmHg ± 6.64 mmHg in measurement zones 1, 2, 3, and 4, respectively. In both groups, no statistically significant change within the measurement zones was observed. Conclusion The predictability of cap thickness in SMILE surgery does not differ from the femto-LASIK flaps created using the same femtosecond laser platform. PMID:23723683

  16. How Bumps on Whale Flippers Delay Stall: An Aerodynamic Model

    NASA Astrophysics Data System (ADS)

    van Nierop, Ernst A.; Alben, Silas; Brenner, Michael P.

    2008-02-01

    Wind tunnel experiments have shown that bumps on the leading edge of model humpback whale flippers cause them to “stall” (i.e., lose lift dramatically) more gradually and at a higher angle of attack. Here we develop an aerodynamic model which explains the observed increase in stall angle. The model predicts that as the amplitude of the bumps is increased, the lift curve flattens out, leading to potentially desirable control properties. We find that stall delay is insensitive to the wavelength of the bumps, in accordance with experimental observations.

  17. Low-cost bump bonding activities at CERN

    NASA Astrophysics Data System (ADS)

    Vähänen, S.; Tick, T.; Campbell, M.

    2010-11-01

    Conventional bumping processes used in the fabrication of hybrid pixel detectors for High Energy Physics (HEP) experiments use electroplating for Under Bump Metallization (UBM) and solder bump deposition. This process is laborious, involves time consuming photolithography and can only be performed using whole wafers. Electroplating has been found to be expensive when used for the low volumes which are typical of HEP experiments. In the low-cost bump bonding development work, electroless deposition technology of UBM is studied as an alternative to the electroplating process in the bump size / pitch window beginning from 20 μm / 50 μm. Electroless UBM deposition used in combination with solder transfer techniques has the potential to significantly lower the cost of wafer bumping without requiring increased wafer volumes. A test vehicle design of sensor and readout chip, having daisy chains and Kelvin bump structures, was created to characterize the flip chip process with electroless UBM. Two batches of test vehicle wafers were manufactured with different bump pad metallization. Batch #1 had AlSi(1%) metallization, which is similar to the one used on sensor wafers, and Batch #2 had AlSi(2%)Cu(1%) metallization, which is very similar to the one used on readout wafers. Electroless UBMs were deposited on both wafer batches. In addition, electroplated Ni UBM and SnPb solder bumps were grown on the test sensor wafers. Test assemblies were made by flip chip bonding the solder-bumped test sensors against the test readout chips with electroless UBMs. Electrical yields and individual joint resistances were measured from assemblies, and the results were compared to a well known reference technique based on electroplated solder bumps structures on both chips. The electroless UBMs deposited on AlSi(2%)Cu(1%) metallization showed excellent electrical yields and small tolerances in individual joint resistance. The results from the UBMs deposited on AlSi(1%) metallization were non

  18. On the efficacy of per-relation basis performance evaluation for PPI extraction and a high-precision rule-based approach

    PubMed Central

    2013-01-01

    Background Most previous Protein Protein Interaction (PPI) studies evaluated their algorithms' performance based on "per-instance" precision and recall, in which the instances of an interaction relation were evaluated independently. However, we argue that this standard evaluation method should be revisited. In a large corpus, the same relation can be described in various different forms and, in practice, correctly identifying not all but a small subset of them would often suffice to detect the given interaction. Methods In this regard, we propose a more pragmatic "per-relation" basis performance evaluation method instead of the conventional per-instance basis method. In the per-relation basis method, only a subset of a relation's instances needs to be correctly identified to make the relation positive. In this work, we also introduce a new high-precision rule-based PPI extraction algorithm. While virtually all current PPI extraction studies focus on improving F-score, aiming to balance the performance on both precision and recall, in many realistic scenarios involving large corpora, one can benefit more from a high-precision algorithm than a high-recall counterpart. Results We show that our algorithm not only achieves better per-relation performance than previous solutions but also serves as a good complement to the existing PPI extraction tools. Our algorithm improves the performance of the existing tools through simple pipelining. Conclusion The significance of this research can be found in that this research brought new perspective to the performance evaluation of PPI extraction studies, which we believe is more important in practice than existing evaluation criteria. Given the new evaluation perspective, we also showed the importance of a high-precision extraction tool and validated the efficacy of our rule-based system as the high-precision tool candidate. PMID:23566263

  19. New pulsed orbit bump magnets for the Fermilab Booster Synchrotron

    SciTech Connect

    Lackey, J.R.; Carson, J.A.; Ginsburg, C.M.; Glass, H.D.; Harding, D.J.; Kashikhin, V.S.; Makarov, A.; Prebys, E.J.; /Fermilab

    2005-05-01

    The beam from the Fermilab Linac is injected onto a bump in the closed orbit of the Booster Synchrotron where a carbon foil strips the electrons from the Linac's negative ion hydrogen beam. Although the Booster itself runs at 15 Hz, heat dissipation in the orbit bump magnets has been one limitation to the fraction of the cycles that can be used for beam. New 0.28 T pulsed dipole magnets have been constructed that will fit into the same space as the old ones, run at the full repetition rate of the Booster, and provide a larger bump to allow a cleaner injection orbit. The new magnets use a ferrite in the yoke rather than laminated steel.

  20. Full waveform inversion with an auxiliary bump functional

    NASA Astrophysics Data System (ADS)

    Bharadwaj, Pawan; Mulder, Wim; Drijkoningen, Guy

    2016-04-01

    Least-squares inversion of seismic arrivals can provide remarkably detailed models of the Earth's subsurface. However, cycle skipping associated with these oscillatory arrivals is the main cause for local minima in the least-squares objective function. Therefore, it is often difficult for descent methods to converge to the solution without an accurate initial large-scale velocity estimate. The low frequencies in the arrivals, needed to update the large-scale components in the velocity model, are usually unreliable or absent. To overcome this difficulty, we propose a multi-objective inversion scheme that uses the conventional least-squares functional along with an auxiliary data-domain objective. As the auxiliary objective effectively replaces the seismic arrivals by bumps, we call it the bump functional. The bump functional minimization can be made far less sensitive to cycle skipping and can deal with multiple arrivals in the data. However, it can only be used as an auxiliary objective since it usually does not provide a unique model after minimization The role of the bump functional during the multi-objective inversion is to guide the optimization towards the global minimum by pulling the trapped solution out of the local minima associated with the least-squares functional whenever necessary. The computational complexity of the bump functional is equivalent to that of the least-squares functional. In this paper, we describe various characteristics of the bump functional using simple and illustrative numerical examples. We also demonstrate the effectiveness of the proposed multi-objective inversion scheme by considering more realistic examples. These include synthetic and field data from a cross-well experiment, surface-seismic synthetic data with reflections and synthetic data with refracted arrivals at long offsets.

  1. Full waveform inversion with an auxiliary bump functional

    NASA Astrophysics Data System (ADS)

    Bharadwaj, Pawan; Mulder, Wim; Drijkoningen, Guy

    2016-08-01

    Least-squares inversion of seismic arrivals can provide remarkably detailed models of the Earth's subsurface. However, cycle skipping associated with these oscillatory arrivals is the main cause for local minima in the least-squares objective function. Therefore, it is often difficult for descent methods to converge to the solution without an accurate initial large-scale velocity estimate. The low frequencies in the arrivals, needed to update the large-scale components in the velocity model, are usually unreliable or absent. To overcome this difficulty, we propose a multi-objective inversion scheme that uses the conventional least-squares functional along with an auxiliary data-domain objective. As the auxiliary objective effectively replaces the seismic arrivals by bumps, we call it the bump functional. The bump functional minimization can be made far less sensitive to cycle skipping and can deal with multiple arrivals in the data. However, it can only be used as an auxiliary objective since it usually does not provide a unique model after minimization even when the regularized-least-squares functional has a unique global minimum and hence a unique solution. The role of the bump functional during the multi-objective inversion is to guide the optimization towards the global minimum by pulling the trapped solution out of the local minima associated with the least-squares functional whenever necessary. The computational complexity of the bump functional is equivalent to that of the least-squares functional. In this paper, we describe various characteristics of the bump functional using simple and illustrative numerical examples. We also demonstrate the effectiveness of the proposed multi-objective inversion scheme by considering more realistic examples. These include synthetic and field data from a cross-well experiment, surface-seismic synthetic data with reflections and synthetic data with refracted arrivals at long offsets.

  2. Development of indium bumping technology through AZ9260 resist electroplating

    NASA Astrophysics Data System (ADS)

    Huang, Qiuping; Xu, Gaowei; Yuan, Yuan; Cheng, Xiao; Luo, Le

    2010-05-01

    Indium bumping is very critical technology in the application of high-density interconnection between a FPA (focal plane array) and a Si ROIC (read-out integrated circuit) by flip-chip bonding. In this paper, the indium BGA (ball grid array) chips are prepared with an electroplating method on the Si substrate. With such a method, the first difficulty arises in removing the seed layer. Two ways, including IBE (ion beam etching) and lift-off, are adopted to overcome it. The results show that the lift-off process is effective but not IBE. During the reflow process, many indium bumps fall off the substrate. Two ways are tried to solve this problem: one is to optimize the reflow profile and the other is to thicken the wetting layer. The results show that these two ways can effectively improve such status. The barrier effects of the UBM (under bump metallization) for indium, which are Ti/Pt (300 Å/200 Å) and Ti/Pt/Au/Ep Au (300 Å/200 Å/1000 Å/4 µm), are also investigated. Experimental results indicate that both of them can be used in application of integration of the FPA and ROIC. Reliability of indium bumps with these two kinds of UBM is evaluated by the shear test. The results show that their shear strength has a significant increase after reflow. For the indium bump with UBM of Ti/Pt/Au/Ep Au (300 Å/200 Å/1000 Å/4 µm), IMC (intermetallic compounds) at the interface of Au-In can strengthen the indium bump but may change the plasticity of indium.

  3. Growth Characteristics Downstream of a Shallow Bump: Computation and Experiment

    NASA Technical Reports Server (NTRS)

    Joslin, Ronald D.; Grosch, Chester E.

    1996-01-01

    Measurements of the velocity field created by a shallow bump on a wall revealed that an energy peak in the spanwise spectrum associated with the driver decays and an initially small-amplitude secondary mode rapidly grows with distance downstream of the bump. Linear theories could not provide an explanation for this growing mode. The present Navier-Stokes simulation replicates and confirms the experimental results. Insight into the structure of the flow was obtained from a study of the results of the calculations and is presented.

  4. Dispersion in closed, off-axis orbit bumps

    NASA Astrophysics Data System (ADS)

    Apsimon, R.; Esberg, J.; Owen, H.

    2016-09-01

    In this paper we present a proof to show that there exists no system of linear or nonlinear optics which can simultaneously close multiple local orbit bumps and dispersion through a single beam transport region. The second combiner ring in the CLIC drive beam recombination system, CR2, is used as an example of where such conditions are necessary. We determine the properties of a lattice which is capable of closing the local orbit bumps and dispersion and show that all resulting solutions are either unphysical or trivial.

  5. Validation of two real-time RT-PCR methods for foot-and-mouth disease diagnosis: RNA-extraction, matrix effect, uncertainty of measurement and precision.

    PubMed

    Goris, Nesya; Vandenbussche, Frank; Herr, Cécile; Villers, Jérôme; Van der Stede, Yves; De Clercq, Kris

    2009-09-01

    Real-time reverse transcription polymerase chain reaction (rRT-PCR) assays are being used routinely for diagnosing foot-and-mouth disease virus (FMDV). Although most laboratories determine analytical and diagnostic sensitivity and specificity, a thorough validation in terms of establishing optimal RNA-extraction conditions, matrix effect, uncertainty of measurement and precision is not performed or reported generally. In this study, different RNA-extraction procedures were compared for two FMDV rRT-PCRs. The NucleoSpin columns available commercially combined high extraction efficiency with ease-of-automation. Furthermore, six different FMDV-negative matrices were spiked with a dilution series of FMDV SAT1 ZIM 25/89. Compared to cell-culture-spiked viral control samples, no matrix effect on the analytical sensitivity was found for blood or foot epithelium. Approximately 1log(10) reduction in detection limit was noted for faecal and tongue epithelium samples, whereas a 3log(10) decrease was observed for spleen samples. By testing the same dilution series in duplicate on 10 different occasions, an estimation of uncertainty of measurement and precision was obtained using blood as matrix. Both rRT-PCRs produced highly precise results emphasising their potential to replace conventional virological methods. The uncertainty measurement, as described in this study, proved to be a useful tool to evaluate the probability of making a wrong decision. PMID:19447138

  6. Salvaged castings and methods of salvaging castings with defective cast cooling bumps

    DOEpatents

    Johnson, Robert Alan; Schaeffer, Jon Conrad; Lee, Ching-Pang; Abuaf, Nesim; Hasz, Wayne Charles

    2002-01-01

    Castings for gas turbine parts exposed on one side to a high-temperature fluid medium have cast-in bumps on an opposite cooling surface side to enhance heat transfer. Areas on the cooling surface having defectively cast bumps, i.e., missing or partially formed bumps during casting, are coated with a braze alloy and cooling enhancement material to salvage the part.

  7. Numerical characterization of bump formation in the runaway electron tail

    NASA Astrophysics Data System (ADS)

    Decker, J.; Hirvijoki, E.; Embreus, O.; Peysson, Y.; Stahl, A.; Pusztai, I.; Fülöp, T.

    2016-02-01

    Runaway electrons are generated in a magnetized plasma when the parallel electric field exceeds a critical value. For such electrons with energies typically reaching tens of MeV, the Abraham-Lorentz-Dirac (ALD) radiation force, in reaction to the synchrotron emission, is significant and can be the dominant process limiting electron acceleration. The effect of the ALD force on runaway electron dynamics in a homogeneous plasma is investigated using the relativistic finite-difference Fokker-Planck codes LUKE (Decker and Peysson 2004 Report EUR-CEA-FC-1736, Euratom-CEA), and CODE (Landreman et al 2014 Comput. Phys. Commun. 185 847). The time evolution of the distribution function is analyzed as a function of the relevant parameters: parallel electric field, background magnetic field, and effective charge. Under the action of the ALD force, we find that runaway electrons are subject to an energy limit, and that the electron distribution evolves towards a steady-state. In addition, a bump is formed in the tail of the electron distribution function if the electric field is sufficiently strong. The mechanisms leading to the bump formation and energy limit involve both the parallel and perpendicular momentum dynamics; they are described in detail. An estimate for the bump location in momentum space is derived. We observe that the energy of runaway electrons in the bump increases with the electric field amplitude, while the population increases with the bulk electron temperature. The presence of the bump divides the electron distribution into a runaway beam and a bulk population. This mechanism may give rise to beam-plasma types of instabilities that could, in turn, pump energy from runaway electrons and alter their confinement.

  8. Study on a robust insert-bump (ISB) bonding technique for a 3D package

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Song, J. Y.; Kim, S. M.; Kim, Y. J.; Lee, Y. K.

    2016-07-01

    The Cu pillar bump to Cu pillar bump bonding process, commonly used in bonding technology for the 3D stacking of TSV (through silicon via) formed chips, requires an additional process for the generation of bumps on the face and back-side of the chip, and it has a drawback in that it is structurally vulnerable to mechanical stresses, such as thermal stress. This study proposes an ISB (insert-bump) bonding process to overcome such drawbacks. Compared to the conventional Cu pillar bump to Cu pillar bump bonding process, the ISB bonding process has advantages in that it is simple and has high mechanical reliability of the package due to the mechanical interlocking. The stress distributions at the joints of the packages produced from Cu pillar bump to Cu pillar bump bonding and ISB processes were compared and analyzed through FEM analyses, and characteristics analyses of the fracture mode and joint characteristics; process variable optimization with respect to the bonding parameters was also conducted through experiments. The results of the analyses and experiments verified that the ISB bonding process yields a bonding strength of 917.6 mgf/bump, which is approximately twice as much as that of the conventional Cu pillar bump to Cu pillar bump bonding, and which yields a highly reliable mechanical structure.

  9. Reliability Investigations on SnAg Bumps on Substrate Pads with Different Pad Finish

    SciTech Connect

    Bauer, R.; Ebersberger, B.; Kupfer, C.; Alexa, L.

    2006-02-07

    SnAg solder bump is one bump type which is used to replace eutectic SnPb bumps. In this work tests have been done to characterize the reliability properties of this bump type. Electromigration (EM) tests, which were accelerated by high current and high temperature and high temperature storage (HTS) tests were performed. It was found that the reliability properties are sensitive to the material combinations in the interconnect stack. The interconnect stack includes substrate pad, pad finish, bump, underbump metallization (UBM) and the chip pad. Therefore separate test groups for SnAg bumps on Cu substrate pads with organic solderability preservative (OSP) finish and the identical bumps on pads with Ni/Au finish were used. In this paper the reliability test results and the corresponding failure analysis are presented. Some explanations about the differences in formation of intermetallic compounds (IMCs) are given.

  10. Bumps and potholes on the road to network computing

    SciTech Connect

    Watson, R.W.

    1990-07-01

    Network computing in a supercomputer environment offers the potential to improve user productivity and enable users to take advantage of the rapidly improving cost/performance of microelectronics through use of hierarchies of processing, storage, I/O and communication resources. Our experience to date indicates that to realize the potential will not only require improvements in operating systems and programming environments, but more importantly will require very high availability networks and a new support infrastructure. This paper outlines some of the potholes and bumps we have run into during recent years in our goal to make network computing an everyday reality for our user community. While some recommendations are made that can smooth the ride, most of the potholes and bumps yet remain to be leveled. 2 figs.

  11. The physics of bump drafting in car racing

    NASA Astrophysics Data System (ADS)

    Fiolhais, Miguel C. N.; Amor dos Santos, Susana

    2014-11-01

    The technique of bump drafting, also known as two-car drafting in motorsports, is analysed in the framework of Newtonian mechanics and simple aerodynamic drag forces. As an apparent unnatural effect that often pleases the enthusiasts of car racing, bump drafting provides a unique pedagogical opportunity for students to gain insights into the physics of drag in moving vehicles. In the context of a physics undergraduate course, it is shown that the dynamics of two moving cars in the same air slipstream on a straight line allows them to increase their speed up to a factor of \\sqrt{2} . This conclusion is also extended to an arbitrary number of n identical moving cars, resulting in an increase of \\sqrt{n} .

  12. Bump formation in a binary attractor neural network

    SciTech Connect

    Koroutchev, Kostadin; Korutcheva, Elka

    2006-02-15

    The conditions for the formation of local bumps in the activity of binary attractor neural networks with spatially dependent connectivity are investigated. We show that these formations are observed when asymmetry between the activity during the retrieval and learning is imposed. An analytical approximation for the order parameters is derived. The corresponding phase diagram shows a relatively large and stable region where this effect is observed, although critical storage and information capacities drastically decrease inside that region. We demonstrate that the stability of the network, when starting from the bump formation, is larger than the stability when starting even from the whole pattern. Finally, we show a very good agreement between the analytical results and the simulations performed for different topologies of the network.

  13. Rationalizing the bumps on whale flippers using basic aerodynamic theory

    NASA Astrophysics Data System (ADS)

    van Nierop, Ernst; Alben, Silas; Brenner, Michael

    2006-11-01

    Recent experiments and numerics demonstrated that bumps on the leading edge of humpback whale flippers can lead to an increase in the lift/drag ratio and an increase in the stall angle, as compared to smooth flippers. Using basic aerodynamic theory (potential flow around a Joukowski profile, combined with lifting-line theory) we attempt to rationalize the experimental and numerical findings. We use this basic theory to find perturbations which could lead to an increase in stall angle.

  14. Characterization of indium and solder bump bonding for pixel detectors

    SciTech Connect

    Selcuk Cihangir and Simon Kwan

    2000-09-28

    A review of different bump-bonding processes used for pixel detectors is given. A large scale test on daisy-chained components from two vendors has been carried out at Fermilab to characterize the yield of these processes. The vendors are Advanced Interconnect Technology Ltd. (AIT) of Hong Kong and MCNC in North Carolina, US. The results from this test are presented and technical challenges encountered are discussed.

  15. A precise extraction of the induced polarization in the 4He(e,e'p)3H reaction

    SciTech Connect

    S.P. Malace, M. Paolone, S. Strauch

    2011-01-01

    We measured with unprecedented precision the induced polarization Py in 4He(e,e'p)3H at Q^2 = 0.8 (GeV/c)^2 and 1.3 (GeV/c)^2. The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are over-estimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin independent charge-exchange term in the latter calculation.

  16. Precision measurement of the ratio B(t→Wb)/B(t→Wq) and extraction of V(tb).

    PubMed

    Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Aoki, M; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Ding, P F; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Guo, F; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jamin, D; Jayasinghe, A; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kulikov, S; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Padilla, M; Pal, A; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Piegaia, R; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Polozov, P; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Salcido, P; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stolin, V; Stoyanova, D A; Strauss, M; Strom, D; Stutte, L; Suter, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2011-09-16

    We present a measurement of the ratio of top quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a d, s, or b quark, in the lepton+jets and dilepton tt final states. The measurement uses data from 5.4 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R=0.90±0.04, and we extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V(tb)| as |V(tb)|=0.95±0.02, assuming unitarity of the 3×3 CKM matrix. PMID:22026765

  17. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    NASA Astrophysics Data System (ADS)

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D'Angelo, A.; Dashyan, N.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Livingston, K.; Lu, H. Y.; Mayer, M.; MacGregor, I. J. D.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Net, L. A.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Simonyan, A.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Voutier, E.; Walford, N. K.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-11-01

    We present the final results for the deuteron spin structure functions obtained from the full data set collected in 2000-2001 with Jefferson Lab's continuous electron beam accelerator facility (CEBAF) using the CEBAF large acceptance spectrometer (CLAS). Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.8 GeV were scattered from deuteron (15ND3 ) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double-spin asymmetry, the virtual photon absorption asymmetry A1d and the polarized structure function g1d were extracted over a wide kinematic range (0.05 GeV2extract from these data the polarized structure functions A1n and g1n of the (bound) neutron, which are so far unknown in the resonance region, W <2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations, as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x , a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the operator product expansion.

  18. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    DOE PAGESBeta

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; et al

    2015-11-02

    In this study, we present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron (15ND3) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry Ad1 and the polarized structure function gd1 were extracted over a wide kinematic range (0.05 GeV2 < Q2 < 5 GeV2 and 0.9 GeV < W < 3 GeV). We use an unfolding procedure andmore » a parametrization of the corresponding proton results to extract from these data the polarized structure functions An1 and g1n of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion.« less

  19. A study of thermal cycling and radiation effects on indium and solder bump bonding

    SciTech Connect

    Selcuk Cihangir et al.

    2001-09-12

    The BTeV hybrid pixel detector is constructed of readout chips and sensor arrays which are developed separately. The detector is assembled by flip-chip mating of the two parts. This method requires the availability of highly reliable, reasonably low cost fine-pitch flip-chip attachment technology. We have tested the quality of two bump-bonding technologies; indium bumps (by Advanced Interconnect Technology Ltd. (AIT) of Hong Kong) and fluxless solder bumps (by MCNC in North Carolina, USA). The results have been presented elsewhere[1]. In this paper we describe tests we performed to further evaluate these technologies. We subjected 15 indium bump-bonded and 15 fluxless solder bump-bonded dummy detectors through a thermal cycle and then a dose of radiation to observe the effects of cooling, heating and radiation on bump-bonds.

  20. Aqueous-based thick photoresist removal for bumping applications

    NASA Astrophysics Data System (ADS)

    Moore, John C.; Brewer, Alex J.; Law, Alman; Pettit, Jared M.

    2015-03-01

    Cleaning processes account for over 25% of processing in microelectronic manufacturing [1], suggesting electronics to be one of the most chemical intensive markets in commerce. Industry roadmaps exist to reduce chemical exposure, usage, and waste [2]. Companies are encouraged to create a safer working environment, or green factory, and ultimately become certified similar to LEED in the building industry [3]. A significant step in this direction is the integration of aqueous-based photoresist (PR) strippers which eliminate regulatory risks and cut costs by over 50%. One of the largest organic solvent usages is based upon thick PR removal during bumping processes [4-6]. Using market projections and the benefits of recycling, it is estimated that over 1,000 metric tons (mt) of residuals originating from bumping processes are incinerated or sent to a landfill. Aqueous-based stripping would eliminate this disposal while also reducing the daily risks to workers and added permitting costs. Positive-tone PR dissolves in aqueous strippers while negative-tone systems are lifted-off from the substrate, bumps, pillars, and redistribution layers (RDL). While the wafers are further processed and rinsed, the lifted-off PR is pumped from the tank, collected onto a filter, and periodically back-flushed to the trash. The PR solids become a non-hazardous plastic waste while the liquids are mixed with the developer stream, neutralized, filtered, and in most cases, disposed to the sewer. Regardless of PR thickness, removal processes may be tuned to perform in <15min, performing at rates nearly 10X faster than solvents with higher bath lives. A balanced formula is safe for metals, dielectrics, and may be customized to any fab.

  1. Study of Electromigration-Induced Failures on Cu Pillar Bumps Joined to OSP and ENEPIG Substrates

    NASA Astrophysics Data System (ADS)

    Hsiao, Yu-Hsiang; Lin, Kwang-Lung; Lee, Chiu-Wen; Shao, Yu-Hsiu; Lai, Yi-Shao

    2012-12-01

    This work studies electromigration (EM)-induced failures on Cu pillar bumps joined to organic solderability preservative (OSP) on Cu substrates (OSP-bumps) and electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) under bump metallurgy (UBM) on Cu substrates (ENEPIG-bumps). Two failure modes (Cu pad consumption and gap formation) were found with OSP-bumps, but only one failure mode (gap formation) was found with ENEPIG-bumps. The main interfacial compound layer was the Cu6Sn5 compound, which suffered significant EM-induced dissolution, eventually resulting in severe Cu pad consumption at the cathode side for OSP-bumps. A (Cu,Ni)6Sn5 layer with strong resistance to EM-induced dissolution exists at the joint interface when a nickel barrier layer is incorporated at the cathode side (Ni or ENEPIG), and these imbalanced atomic fluxes result in the voids and gap formation. OSP-bumps showed better lifetime results than ENEPIG-bumps for several current stressing conditions. The inverse Cu atomic flux ( J Cu,chem) which diffuses from the Cu pad to cathode side retards the formation of voids. The driving force for J Cu,chem comes from the difference in chemical potential between the (Cu,Ni)6Sn5 and Cu6Sn5 phases.

  2. Planning and drilling geothermal energy extraction hole EE-2: a precisely oriented and deviated hole in hot granitic rock

    SciTech Connect

    Helmick, C.; Koczan, S.; Pettitt, R.

    1982-04-01

    During the preceding work (Phase I) of the Hot Dry Rock (HDR) Geothermal Energy Project at Fenton Hill, two holes were drilled to a depth of nearly 3048 m (10,000 ft) and connected by a vertical hydraulic fracture. In this phase, water was pumped through the underground reservoir for approximately 417 days, producing an energy equivalent of 3 to 5 MW(t). Energy Extraction Hole No. 2 (EE-2) is the first of two deep holes that will be used in the Engineering-Resource Development System (Phase II) of the ongoing HDR Project of the Los Alamos National Laboratory. This phase of the work consists of drilling two parallel boreholes, inclined in their lower, open-hole sections at 35/sup 0/ to the vertical and separated by a vertical distance of 366 m (1200 ft) between the inclined parts of the drill holes. The holes will be connected by a series of vertical, hydraulically produced fractures in the Precambrian granitic rock complex. EE-2 was drilled to a depth of 4660 m (15,289 ft), where the bottom-hole temperature is approximately 320/sup 0/C (608/sup 0/F). Directional drilling techniques were used to control the azimuth and deviation of the hole. Upgrading of the temperature capability of existing hardware, and development of new equipment was necessary to complete the drilling of the hole in the extremely hot, hard, and abrasive granitic formation. The drilling history and the problems with bits, directional tools, tubular goods, cementing, and logging are described. A discussion of the problems and recommendations for overcoming them are also presented.

  3. Analysis and design modifications for upgrade of storage ring bump pulse system driving the injection bump magnets at the ALS

    SciTech Connect

    Stover, G.D.

    1995-04-01

    A fast (4.0 ms half period) resonant discharge pulse system, using SCRs, was designed and constructed to drive the injection bump magnet system at the Advanced Light Source (ALS). The commissioning process revealed a high frequency resonance (T = 800 NS) superimposed on the driver discharge wave form. In addition, the peak amplitude of the magnet load recovery current exceeded design specifications. A SPICE analysis confirmed the suspected mechanisms for the parasitic ringing and the excessive load current {open_quotes}undershoot{close_quotes}. This paper will address the subsequent analysis, measurements, and modifications carried out during the maintenance shutdown in June 1993.

  4. Sensory feedback in a bump attractor model of path integration.

    PubMed

    Poll, Daniel B; Nguyen, Khanh; Kilpatrick, Zachary P

    2016-04-01

    Mammalian spatial navigation systems utilize several different sensory information channels. This information is converted into a neural code that represents the animal's current position in space by engaging place cell, grid cell, and head direction cell networks. In particular, sensory landmark (allothetic) cues can be utilized in concert with an animal's knowledge of its own velocity (idiothetic) cues to generate a more accurate representation of position than path integration provides on its own (Battaglia et al. The Journal of Neuroscience 24(19):4541-4550 (2004)). We develop a computational model that merges path integration with feedback from external sensory cues that provide a reliable representation of spatial position along an annular track. Starting with a continuous bump attractor model, we explore the impact of synaptic spatial asymmetry and heterogeneity, which disrupt the position code of the path integration process. We use asymptotic analysis to reduce the bump attractor model to a single scalar equation whose potential represents the impact of asymmetry and heterogeneity. Such imperfections cause errors to build up when the network performs path integration, but these errors can be corrected by an external control signal representing the effects of sensory cues. We demonstrate that there is an optimal strength and decay rate of the control signal when cues appear either periodically or randomly. A similar analysis is performed when errors in path integration arise from dynamic noise fluctuations. Again, there is an optimal strength and decay of discrete control that minimizes the path integration error. PMID:26754972

  5. Sensitive and precise HPLC method with back-extraction clean-up step for the determination of sildenafil in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Strach, Beata; Wyska, Elżbieta; Pociecha, Krzysztof; Krupa, Anna; Jachowicz, Renata

    2015-10-01

    A sensitive HPLC method was developed and validated for the determination of sildenafil concentrations in rat plasma (200 μL) using a liquid-liquid extraction procedure and paroxetine as an internal standard. In order to eliminate interferences and improve the peak shape, a back-extraction into an acidic solution was utilized. Chromatographic separation was achieved on a cyanopropyl bonded-phase column with a mobile phase composed of 50 m m potassium dihydrogen phosphate buffer (pH 4.5) and acetonitrile (75:25, v/v), pumped at the flow rate of 1 mL/min. A UV detector was set at 230 nm. A calibration curve was constructed within a concentration range from 10 to 1500 ng/mL. The limit of detection was 5 ng/mL. The inter- and intra-day precisions of the assay were in the ranges 2.91-7.33 and 2.61-6.18%, respectively, and the accuracies for inter- and intra-day runs were within 0.14-3.92 and 0.44-2.96%, respectively. The recovery of sildenafil was 85.22 ± 4.54%. Tests confirmed the stability of sildenafil in plasma during three freeze-thaw cycles and during long-term storage at -20 and -80°C for up to 2 months. The proposed method was successfully applied to a pharmacokinetic study in rats. PMID:25864807

  6. Effect of Compressibility on the Flow past a Two-dimensional Bump

    NASA Technical Reports Server (NTRS)

    Lindsey, W F; Daley, Bernard N

    1952-01-01

    An investigation has been conducted to determine experimentally the effects of compressibility on the flow past a bump and to compare the experimentally determined results with theory. Pressure measurements and Schlieren photographs were made of the flow past two bumps having thickness-chord ratios of 0.10 and 0.30 at Mach numbers between 0.20 and 0.84

  7. Computer analysis of flow perturbations generated by placement of choke bumps in a wind tunnel

    NASA Technical Reports Server (NTRS)

    Campbell, R. L.

    1981-01-01

    An inviscid analytical study was conducted to determine the upstream flow perturbations caused by placing choke bumps in a wind tunnel. A computer program based on the stream-tube curvature method was used to calculate the resulting flow fields for a nominal free-stream Mach number range of 0.6 to 0.9. The choke bump geometry was also varied to investigate the effect of bump shape on the disturbance produced. Results from the study indicate that a region of significant variation from the free-stream conditions exists upstream of the throat of the tunnel. The extent of the disturbance region was, as a rule, dependent on Mach number and the geometry of the choke bump. In general, the upstream disturbance distance decreased for increasing nominal free-stream Mach number and for decreasing length-to-height ratio of the bump. A polynomial-curve choke bump usually produced less of a disturbance than did a circular-arc bump and going to an axisymmetric configuration (modeling choke bumps on all the tunnel walls) generally resulted in a lower disturbance than with the corresponding two dimensional case.

  8. Dust and gas density evolution at a radial pressure bump in protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Taki, Tetsuo; Fujimoto, Masaki; Ida, Shigeru

    2016-06-01

    We investigate the simultaneous evolution of dust and gas density profiles at a radial pressure bump located in a protoplanetary disk. If dust particles are treated as test particles, a radial pressure bump traps dust particles that drift radially inward. As the dust particles become more concentrated at the gas pressure bump, however, the drag force from dust to gas (back-reaction), which is ignored in a test-particle approach, deforms the pressure bump. We find that the pressure bump is completely deformed by the back-reaction when the dust-to-gas mass ratio reaches ~ 1 for a slower bump restoration. The direct gravitational instability of dust particles is inhibited by the bump destruction. In the dust-enriched region, the radial pressure support becomes ~ 10-100 times lower than the global value set initially. Although the pressure bump is a favorable place for streaming instability (SI), the flattened pressure gradient inhibits SI from forming large particle clumps corresponding to 100-1000 km sized bodies, which has been previously proposed. If SI occurs there, the dust clumps formed would be 10-100 times smaller, that is, of about 1-100 km.

  9. A Metal Bump Bonding Method Using Ag Nanoparticles as Intermediate Layer

    NASA Astrophysics Data System (ADS)

    Fu, Weixin; Nimura, Masatsugu; Kasahara, Takashi; Mimatsu, Hayata; Okada, Akiko; Shoji, Shuichi; Ishizuka, Shugo; Mizuno, Jun

    2015-11-01

    The future development of low-temperature and low-pressure bonding technology is necessary for fine-pitch bump application. We propose a bump structure using Ag nanoparticles as an intermediate layer coated on a fine-pitch Cu pillar bump. The intermediate layer is prepared using an efficient and cost-saving squeegee-coating method followed by a 100°C baking process. This bump structure can be easily flattened before the bonding process, and the low-temperature sinterability of the nanoparticles is retained. The bonding experiment was successfully performed at 250°C and 39.8 MPa and the bonding strength was comparable to that achieved via other bonding technology utilizing metal particles or porous material as bump materials.

  10. Study of indium and solder bumps for the BTeV Pixel Detector

    SciTech Connect

    Simon W Kwan et al.

    2003-11-05

    The pixel detector proposed for the BTeV experiment at the Fermilab Tevatron will use bump-bonding technology based on either Indium or Pb/Sn solder to connect the front-end readout chips to the silicon pixel sensors. We have studied the strength of the bumps by visual inspection of the bumps bonding silicon sensor modules to dummy chips made out of glass. The studies were done before and after thermal cycles, exposed to intense irradiation, and with the assemblies glued to a graphite substrate. We have also carried out studies on effects of temperature changes on both types of bump bonds by observing the responses of single-chip pixel detectors to an Sr{sup 90} source. We report the results from these studies and our plan to measure the effect of cryogenic temperatures on the bumps.

  11. Single bump, two-color quantum dot camera

    NASA Astrophysics Data System (ADS)

    Varley, E.; Lenz, M.; Lee, S. J.; Brown, J. S.; Ramirez, D. A.; Stintz, A.; Krishna, S.; Reisinger, Axel; Sundaram, Mani

    2007-08-01

    The authors report a two-color, colocated quantum dot based imaging system used to take multicolor images using a single focal plane array (FPA). The dots-in-a-well (DWELL) detectors consist of an active region composed of InAs quantum dots embedded in In.15Ga.85As quantum wells. DWELL samples were grown using molecular beam epitaxy and fabricated into 320×256 focal plane arrays with indium bumps. The FPA was then hybridized to an Indigo ISC9705 readout circuit and tested. Calibrated blackbody measurements at a device temperature of 77K yield midwave infrared and long wave infrared noise equivalent difference in temperature of ˜55 and 70mK.

  12. Extraction of CO2 from air samples for isotopic analysis and limits to ultra high precision delta18O determination in CO2 gas.

    PubMed

    Werner, R A; Rothe, M; Brand, W A

    2001-01-01

    be as long as 20 min for high precision delta18O measurements. The presence of traces of air in almost all CO2 gases that we analyzed was another major source of error. Nitrogen and oxygen in the ion source of our mass spectrometer (MAT 252, Finnigan MAT, Bremen, Germany) give rise to the production of NO2 at the hot tungsten filament. NO2+ is isobaric with C16O18O+ (m/z 46) and interferes with the delta18O measurement. Trace amounts of air are present in CO2 extracted cryogenically from air at -196 degrees C. This air, trapped at the cold surface, cannot be pumped away quantitatively. The amount of air present depends on the surface structure and, hence, the alteration of the measured delta18O value varies with the surface conditions. For automated high precision measurement of the isotopic composition of CO2 of air samples stored in glass flasks an extraction interface ('BGC-AirTrap') was developed which allows 18 analyses (including standards) per day to be made. For our reference CO2-in-air, stored in high pressure cylinders, the long term (>9 months) single sample precision was 0.012 per thousand for delta13C and 0.019 per thousand for delta18O. PMID:11746880

  13. ELECTRONIC SPECTROSCOPY OF MEDIUM-SIZED POLYCYCLIC AROMATIC HYDROCARBONS: IMPLICATIONS FOR THE CARRIERS OF THE 2175 A UV BUMP

    SciTech Connect

    Steglich, M.; Jaeger, C.; Rouille, G.; Huisken, F.; Mutschke, H.; Henning, Th. E-mail: Cornelia.Jaeger@uni-jena.de

    2010-03-20

    Mixtures of polycyclic aromatic hydrocarbons (PAHs) have been produced by means of laser pyrolysis. The main fraction of the extracted PAHs was primarily medium-sized, up to a maximum size of 38 carbon atoms per molecule. The use of different extraction solvents and subsequent chromatographic fractionation provided mixtures of different size distributions. UV-VIS absorption spectra have been measured at low temperature by matrix isolation spectroscopy and at room temperature with PAHs as film-like deposits on transparent substrates. In accordance with semi-empirical calculations, our findings suggest that large PAHs with sizes around 50-60 carbon atoms per molecule could be responsible for the interstellar UV bump at 217.5 nm.

  14. Residue-Free Solder Bumping Using Small AuSn Particles by Hydrogen Radicals

    NASA Astrophysics Data System (ADS)

    Higurashi, Eiji; Chino, Daisuke; Suga, Tadatomo

    An AuSn reflow process using hydrogen radicals as a way to avert the cleaning of flux residues was investigated for its application to solder bumping. AuSn particles (manufactured by a gas atomizer) smaller than 5µm, which are difficult to reflow by conventional methods that use rosin mildly activated (RMA) flux, were used for the experiments. In this process, the reduction effect by the hydrogen radicals removes the surface oxides of the AuSn particles. Excellent wetting between 1-µm-diameter AuSn particles and Ni metallization occurred in hydrogen plasma. Using hydrogen radicals, 100µm-diameter AuSn bumps without voids were successfully formed at a peak temperature of 300°C. The average bump shear strength was approximately 73gf/bump. Bump inspection after shear testing showed that a fracture had occurred between the Au/Ni/Cr under bump metallurgy (UBM) and Si substrate, suggesting sufficient wetting between the AuSn bump and the UBM.

  15. Low-cost bump-bonding processes for high energy physics pixel detectors

    NASA Astrophysics Data System (ADS)

    Caselle, M.; Blank, T.; Colombo, F.; Dierlamm, A.; Husemann, U.; Kudella, S.; Weber, M.

    2016-01-01

    In the next generation of collider experiments detectors will be challenged by unprecedented particle fluxes. Thus large detector arrays of highly pixelated detectors with minimal dead area will be required at reasonable costs. Bump-bonding of pixel detectors has been shown to be a major cost-driver. KIT is one of five production centers of the CMS barrel pixel detector for the Phase I Upgrade. In this contribution the SnPb bump-bonding process and the production yield is reported. In parallel to the production of the new CMS pixel detector, several alternatives to the expensive photolithography electroplating/electroless metal deposition technologies are developing. Recent progress and challenges faced in the development of bump-bonding technology based on gold-stud bonding by thin (15 μm) gold wire is presented. This technique allows producing metal bumps with diameters down to 30 μm without using photolithography processes, which are typically required to provide suitable under bump metallization. The short setup time for the bumping process makes gold-stud bump-bonding highly attractive (and affordable) for the flip-chipping of single prototype ICs, which is the main limitation of the current photolithography processes.

  16. Defects inspection of the solder bumps using self reference technology in active thermography

    NASA Astrophysics Data System (ADS)

    Lu, Xiangning; Shi, Tielin; Han, Jiguang; Liao, Guanglan; Su, Lei; Wang, Suya

    2014-03-01

    With the decrease of solder bumps in dimension and pitch, defects inspection of the solder bumps become more difficult. A nondestructive detection system based on the active thermography has been developed for solder bumps inspection. However, heating non-uniformities and emissivity differences may impede the defects recognition. In this paper, we propose a method using a self reference technology based on a source distribution image (SDI) to eliminate the influence of unevenness in emissivity values and heating power distribution. Three thermograms captured right after the heat pulse are averaged to create the SDI. Then the SDI is subtracted from the original thermograms, and we get the thermal contrast images, in which eight points on the edge of each hot spot are selected as the feature points for the corresponding bump. Thermal difference between the feature points and the central point are adopted to quantify the thermal behaviors of the solder bumps, by which the missing bump is distinguished from the reference bumps. The results show that it is effective using the method to eliminate the impacts of emissivity unevenness and heating non-uniformities on defects identification in the active infrared test.

  17. A study of thermal cycling and radiation effects on indium and solder bump bonds

    SciTech Connect

    Simon Kwan et al.

    2001-12-11

    The BTeV hybrid pixel detector is constructed of readout chips and sensor arrays which are developed separately. The detector is assembled by flip-chip mating of the two parts. This method requires the availability of highly reliable, reasonably low cost fine-pitch flip-chip attachment technology. We have tested the quality of two bump-bonding technologies; indium bumps (by Advanced Interconnect Technology Ltd. (AIT) of Hong Kong) and fluxless solder bumps (by MCNC in North Carolina, USA). The results have been presented elsewhere [1]. In this paper we describe tests we performed to further evaluate these technologies. We subjected 15 indium bump-bonded and 15 fluxless solder bump-bonded dummy detectors through a thermal cycle and then a dose of radiation to observe the effects of cooling, heating and radiation on bump-bonds. We also exercised the processes of HDI mounting and wire bonding to some of the dummy detectors to see the effect of these processes on bump bonds.

  18. Design rule of indium bump in infrared focal plane array for longer cycling life

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoling; Meng, Chao; Zhang, Wei; Lv, Yanqiu; Si, Junjie; Meng, Qingduan

    2016-05-01

    In light of the proposed equivalent method, a three-dimensional structural modeling of InSb infrared focal plane arrays (IRFPAs) is created, and the simulated strain distribution is identical to the deformation distribution on the top surface of InSb IRFPAs. After comparing the deformation features at different regions with the structural characteristics of IRFPAs, we infer that the flatness of InSb IRFPAs will be improved with a thinner indium bump array, and this inference is verified by subsequent simulation results. That is, when the diameter of indium bump is smaller than 20 μm, the simulated Z-components of strain on the whole top surface of InSb IRFPAs is uniform, and the deformation amplitude is small. When the diameter of indium bump is larger than 28 μm, the simulated Z-components of strain increases rapidly with the thicker indium bump, and the flatness of InSb IRFPAs is worsened rapidly. According to the changing trend of deformation amplitude with diameters of indium bump, and employing element pitches normalization method, a design rule of indium bump is proposed. That is, when the diameter of indium bump is shorter than 0.4 times the element pitch, the flatness of InSb IRFPAs is in an acceptable range. This design rule was supported by different IRFPAs with different formats delivered by several main research groups for achieving a longer cycling life.

  19. Thermal Stress of Surface Oxide Layer on Micro Solder Bumps During Reflow

    NASA Astrophysics Data System (ADS)

    Key Chung, C.; Zhu, Z. X.; Kao, C. R.

    2015-02-01

    Micro-bumps are now being developed with diameters smaller than 10 μm. At these dimensions, only very small amounts of solder are used to form the interconnections. Surface oxidation of such small micro-bumps is a critical issue. The key question is whether the oxide film on the solder bumps acts as a barrier to formation of solder joints. In this work, the mechanical stability of the oxide layer on solder bumps was investigated. Solder bumps with 35- μm radii were heated for different times. Auger electron spectroscopy was used to determine the thickness of the oxide layer on the solder bumps. Solder bumps with known oxide layer thicknesses were then heated in a low-oxygen environment (<50 ppm) until they melted. The mechanical stability of the oxide layer was observed by use of a high-speed camera. Results showed that a 14-nm-thick oxide layer on a solder bump of radius 35 μm was able to withstand the molten solder without cracking, leading to a non-wetting solder joint. A thermal stress model of the surface oxide layer revealed that the stress varied substantially with bump size and temperature, and increased almost linearly with temperature. Upon melting, the thermal stress on the oxide increased abruptly, because of the higher thermal expansion of molten solder compared with its solid state. On the basis of the experimental results and the thermal stress model of the oxide film, the maximum oxide thickness that can be tolerated to form a solder joint was determined, e.g. 14 nm oxide can support liquid solder, and thus lead to a non-wetting condition. This work provided a new method of determination of the maximum stress of oxide film for solder joint formation.

  20. Growth of silicon bump induced by swift heavy ion at the silicon oxide-silicon interface

    SciTech Connect

    Carlotti, J.-F.; Touboul, A.D.; Ramonda, M.; Caussanel, M.; Guasch, C.; Bonnet, J.; Gasiot, J.

    2006-01-23

    Thin silicon oxide layers on silicon substrates are investigated by scanning probe microscopy before and after irradiation with 210 MeV Au+ ions. After irradiation and complete chemical etching of the silicon oxide layer, silicon bumps grown on the silicon surface are observed. It is shown that each impinging ion induces one silicon bump at the interface. This observation is consistent with the thermal spike theory. Ion energy loss is transferred to the oxide and induces local melting. Silicon-bump formation is favored when the oxide and oxide-silicon interface are silicon rich.

  1. The velocity field created by a shallow bump in a boundary layer

    NASA Technical Reports Server (NTRS)

    Gaster, Michael; Grosch, Chester E.; Jackson, Thomas L.

    1994-01-01

    We report the results of measurements of the disturbance velocity field generated in a boundary layer by a shallow three-dimensional bump oscillating at a very low frequency on the surface of a flat plate. Profiles of the mean velocity, the disturbance velocity at the fundamental frequency and at the first harmonic are presented. These profiles were measured both upstream and downstream of the oscillating bump. Measurements of the disturbance velocity were also made at various spanwise and downstream locations at a fixed distance from the boundary of one displacement thickness. Finally, the spanwise spectrum of the disturbances at three locations downstream of the bump are presented.

  2. Preparation of Sn—Ag—In ternary solder bumps by electroplating in sequence and reliability

    NASA Astrophysics Data System (ADS)

    Dongliang, Wang; Yuan, Yuan; Le, Luo

    2011-08-01

    This paper describes a technique that can obtain ternary Sn—Ag—In solder bumps with fine pitch and homogenous composition distribution. The mainfeature of this process is that tin-silver and indium are electroplated on copper under bump metallization (UBM) in sequence. After an accurate reflow process, Sn1.8Ag9.4In solder bumps are obtained. It is found that the intermetallic compounds (IMCs) between Sn—Ag—In solder and Cu grow with the reflow time, which results in an increase in Ag concentration in the solder area. So during solidification, more Ag2In nucleates and strengthens the solder.

  3. Optimization of indium bump preparation in infrared focal plane array fabrication

    NASA Astrophysics Data System (ADS)

    Hou, Zhijin; Si, Junjie; Wang, Wei; Wang, Haizhen; Wang, Liwen

    2014-11-01

    Optimization of indium bump preparation in infrared focal plane array (IRFPA) fabrication is presented. Reasons of bringing defective pixels during conventional lift-off and cleanout process in fabrication of indium bump are discussed. IRFPAs are characterized by IRFPA test-bench. Results show that defective pixels of InSb IRFPA are owing to indium bumps connecting through indium residue on the surface of wafer. The characteristic and configuration of defective pixels of InSb IRFPA are given and analyzed. A method of reducing defective pixels through optimizing liftoff and cleanout process in InSb IRFPA is proposed. Results prove that this method is effective.

  4. Pictorial essay: USG of lumps and bumps of the foot and ankle

    PubMed Central

    Botchu, Rajesh; Khan, Aman; Bhatt, Raj

    2010-01-01

    USG is a cost-effective and dynamic way to interrogate superficial lumps and bumps. We present a pictorial review of the USG findings in various “lumps and bumps” of the foot and ankle. PMID:20607019

  5. Experiments on initial and boundary conditions. [for channel flow with bump

    NASA Technical Reports Server (NTRS)

    Moretti, G.

    1981-01-01

    The physical implications of modeling a subsonic boundary in an internal flow with a bump are discussed with reference to the effects of three different models. A numerical treatment of the corners is presented.

  6. Evaluation of advanced microelectronic fluxless solder-bump contacts for hybrid microcircuits

    NASA Technical Reports Server (NTRS)

    Mandal, R. P.

    1976-01-01

    Technology for interconnecting monolithic integrated circuit chips with other components is investigated. The advantages and disadvantages of the current flip-chip approach as compared to other interconnection methods are outlined. A fluxless solder-bump contact technology is evaluated. Multiple solder-bump contacts were formed on silicon integrated circuit chips. The solder-bumps, comprised of a rigid nickel under layer and a compliant solder overlayer, were electroformed onto gold device pads with the aid of thick dry film photomasks. Different solder alloys and the use of conductive epoxy for bonding were explored. Fluxless solder-bump bond quality and reliability were evaluated by measuring the effects of centrifuge, thermal cycling, and high temperature storage on bond visual characteristics, bond electrical continuity, and bond shear tests. The applicability and suitability of this technology for hybrid microelectronic packaging is discussed.

  7. Fluidic Self-Assembly Using Molten Ga Bumps and Its Application to Resonant Tunneling Diodes

    NASA Astrophysics Data System (ADS)

    Nakano, Jun; Shibata, Tomoaki; Morita, Hiroki; Sakamoto, Hiroshi; Mori, Masayuki; Maezawa, Koichi

    2013-11-01

    Fluidic self-assembly (FSA) using molten metal bumps is one of the most promising heterogeneous integration (HI) technologies, which enable us to integrate devices made of various materials on various substrates. We can fabricate the metal bumps using Ga having diameters of 24, 18, 12, and 8 µm with good yield. Using Ga has significant advantages; especially, it includes no toxic metals. These bumps were used for the FSA process of the metal dummy blocks having a diameter of 18 µm, and a good yield of 84% was obtained all over the substrate of about 1×1 cm2. Finally, we applied this method to the resonant tunneling diode (RTD) to verify good electrical, mechanical, and thermal contacts. The RTD device blocks having a diameter of 24 µm have been successfully assembled using the molten Ga bumps. This method is promising for high-performance RTD integration.

  8. The study of selective heating of indium bump in MCT infrared focal plane array

    NASA Astrophysics Data System (ADS)

    Zhang, Haiyan; Cao, Lan; Zhuang, Fulong; Hu, Xiaoning; Gong, Haimei

    2012-10-01

    Generally the electrical interconnectivity between The Mercury Cadmium Telluride (MCT) infrared focal plane array (IRFPA) device and circuit takes the flip chip technology using indium bump as a connection medium. In order to improve the reliability of the interconnectivity indium melting is a common packaging technique at present. This technique is called reflow soldering. The heating is transferred to the indium bump by heating the device and circuit. This heating process will persist about 10 minutes resulting in the MCT material going through a 10 minutes high temperature baking course. This baking process will strongly degenerate the characteristic of the MCT device. Under this circumstance this article gives a new heating technique for indium bump which is call induction heating melting technique. This method realizes the selective heating. While the indium bump is melted by the conduction heating the semiconductor material such as MCT can't be heated.

  9. Indium bump array fabrication on small CMOS circuit for flip-chip bonding

    NASA Astrophysics Data System (ADS)

    Yuyang, Huang; Yuxiang, Zhang; Zhizhen, Yin; Guoxin, Cui; C, Liu H.; Lifeng, Bian; Hui, Yang; Yaohui, Zhang

    2011-11-01

    We demonstrate a novel method for indium bump fabrication on a small CMOS circuit chip that is to be flip-chip bonded with a GaAs/AlGaAs multiple quantum well spatial light modulator. A chip holder with a via hole is used to coat the photoresist for indium bump lift-off. The 1000 μm-wide photoresist edge bead around the circuit chip can be reduced to less than 500 μm, which ensures the integrity of the indium bump array. 64 × 64 indium arrays with 20 μm-high, 30 μm-diameter bumps are successfully formed on a 5 × 6.5 mm2 CMOS chip.

  10. Franz Joseph Gall and music: the faculty and the bump.

    PubMed

    Eling, Paul; Finger, Stanley; Whitaker, Harry

    2015-01-01

    The traditional story maintains that Franz Joseph Gall's (1758-1828) scientific program began with his observations of schoolmates with bulging eyes and good verbal memories. But his search to understand human nature, in particular individual differences in capacities, passions, and tendencies, can also be traced to other important observations, one being of a young girl with an exceptional talent for music. Rejecting contemporary notions of cognition, Gall concluded that behavior results from the interaction of a limited set of basic faculties, each with its own processes for perception and memory, each with its own territory in both cerebral or cerebellar cortices. Gall identified 27 faculties, one being the sense of tone relations or music. The description of the latter is identical in both his Anatomie et Physiologie and Sur les Fonctions du Cerveau et sur Celles de Chacune de ses Parties, where he provided positive and negative evidences and discussed findings from humans and lower animals, for the faculty. The localization of the cortical faculty for talented musicians, he explained, is demonstrated by a "bump" on each side of the skull just above the angle of the eye; hence, the lower forehead of musicians is broader or squarer than in other individuals. Additionally, differences between singing and nonsinging birds also correlate with cranial features. Gall even brought age, racial, and national differences into the picture. What he wrote about music reveals much about his science and creative thinking. PMID:25684283

  11. Bumped kinase inhibitor prohibits egression in Babesia bovis.

    PubMed

    Pedroni, Monica J; Vidadala, Rama Subba Rao; Choi, Ryan; Keyloun, Katelyn R; Reid, Molly C; Murphy, Ryan C; Barrett, Lynn K; Van Voorhis, Wesley C; Maly, Dustin J; Ojo, Kayode K; Lau, Audrey O T

    2016-01-15

    Babesiosis is a global zoonotic disease acquired by the bite of a Babesia-infected Ixodes tick or through blood transfusion with clinical relevance affecting humans and animals. In this study, we evaluated a series of small molecule compounds that have previously been shown to target specific apicomplexan enzymes in Plasmodium, Toxoplasma and Cryptosporidium. The compounds, bumped kinase inhibitors (BKIs), have strong therapeutic potential targeting apicomplexa-specific calcium dependent protein kinases (CDPKs). We investigated if BKIs also show inhibitory activities against piroplasms such as Babesia. Using a subset of BKIs that have promising inhibitory activities to Plasmodium and Toxoplasma, we determined that their actions ranged from 100% and no inhibition against Babesia bovis blood stages. One specific BKI, RM-1-152, showed complete inhibition against B. bovis within 48h and was the only BKI that showed noticeable phenotypic changes to the parasites. Focusing our study on this BKI, we further demonstrated that RM-1-152 has Babesia-static activity and involves the prohibition of merozoite egress while replication and re-invasion of host cells are unaffected. The distinct, abnormal phenotype induced by RM-1-152 suggests that this BKI can be used to investigate less studied cellular processes such as egression in piroplasm. PMID:26790733

  12. The effect of dilution and the use of a post-extraction nucleic acid purification column on the accuracy, precision, and inhibition of environmental DNA samples

    USGS Publications Warehouse

    Mckee, Anna M.; Spear, Stephen F.; Pierson, Todd W.

    2015-01-01

    Isolation of environmental DNA (eDNA) is an increasingly common method for detecting presence and assessing relative abundance of rare or elusive species in aquatic systems via the isolation of DNA from environmental samples and the amplification of species-specific sequences using quantitative PCR (qPCR). Co-extracted substances that inhibit qPCR can lead to inaccurate results and subsequent misinterpretation about a species’ status in the tested system. We tested three treatments (5-fold and 10-fold dilutions, and spin-column purification) for reducing qPCR inhibition from 21 partially and fully inhibited eDNA samples collected from coastal plain wetlands and mountain headwater streams in the southeastern USA. All treatments reduced the concentration of DNA in the samples. However, column purified samples retained the greatest sensitivity. For stream samples, all three treatments effectively reduced qPCR inhibition. However, for wetland samples, the 5-fold dilution was less effective than other treatments. Quantitative PCR results for column purified samples were more precise than the 5-fold and 10-fold dilutions by 2.2× and 3.7×, respectively. Column purified samples consistently underestimated qPCR-based DNA concentrations by approximately 25%, whereas the directional bias in qPCR-based DNA concentration estimates differed between stream and wetland samples for both dilution treatments. While the directional bias of qPCR-based DNA concentration estimates differed among treatments and locations, the magnitude of inaccuracy did not. Our results suggest that 10-fold dilution and column purification effectively reduce qPCR inhibition in mountain headwater stream and coastal plain wetland eDNA samples, and if applied to all samples in a study, column purification may provide the most accurate relative qPCR-based DNA concentrations estimates while retaining the greatest assay sensitivity.

  13. Development of Indium bump bonding for the ATLAS Insertable B-Layer (IBL)

    NASA Astrophysics Data System (ADS)

    Alimonti, G.; Andreazza, A.; Corda, G.; Darbo, G.; Di Gioia, S.; Fiorello, A.; Gariano, G.; Gemme, C.; Meroni, C.; Rovani, A.; Ruscino, E.

    2013-01-01

    About half of the ATLAS pixel modules have been assembled with the Selex indium bump bonding process. The requirements of the ATLAS Insertable B-Layer (IBL) detector ask for larger and thinner chips, two critical parameters for bonding processes. We report on the research and development carried on with Selex to produce modules with 100 μm thick and 18.8 × 20.2 mm2 area read out chips bonded with indium bumps.

  14. Multi-bump solutions in a neural field model with external inputs

    NASA Astrophysics Data System (ADS)

    Ferreira, Flora; Erlhagen, Wolfram; Bicho, Estela

    2016-07-01

    We study the conditions for the formation of multiple regions of high activity or "bumps" in a one-dimensional, homogeneous neural field with localized inputs. Stable multi-bump solutions of the integro-differential equation have been proposed as a model of a neural population representation of remembered external stimuli. We apply a class of oscillatory coupling functions and first derive criteria to the input width and distance, which relate to the synaptic couplings that guarantee the existence and stability of one and two regions of high activity. These input-induced patterns are attracted by the corresponding stable one-bump and two-bump solutions when the input is removed. We then extend our analytical and numerical investigation to N-bump solutions showing that the constraints on the input shape derived for the two-bump case can be exploited to generate a memory of N > 2 localized inputs. We discuss the pattern formation process when either the conditions on the input shape are violated or when the spatial ranges of the excitatory and inhibitory connections are changed. An important aspect for applications is that the theoretical findings allow us to determine for a given coupling function the maximum number of localized inputs that can be stored in a given finite interval.

  15. Stability of bumps in piecewise smooth neural fields with nonlinear adaptation

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Zachary P.; Bressloff, Paul C.

    2010-06-01

    We study the linear stability of stationary bumps in piecewise smooth neural fields with local negative feedback in the form of synaptic depression or spike frequency adaptation. The continuum dynamics is described in terms of a nonlocal integrodifferential equation, in which the integral kernel represents the spatial distribution of synaptic weights between populations of neurons whose mean firing rate is taken to be a Heaviside function of local activity. Discontinuities in the adaptation variable associated with a bump solution means that bump stability cannot be analyzed by constructing the Evans function for a network with a sigmoidal gain function and then taking the high-gain limit. In the case of synaptic depression, we show that linear stability can be formulated in terms of solutions to a system of pseudo-linear equations. We thus establish that sufficiently strong synaptic depression can destabilize a bump that is stable in the absence of depression. These instabilities are dominated by shift perturbations that evolve into traveling pulses. In the case of spike frequency adaptation, we show that for a wide class of perturbations the activity and adaptation variables decouple in the linear regime, thus allowing us to explicitly determine stability in terms of the spectrum of a smooth linear operator. We find that bumps are always unstable with respect to this class of perturbations, and destabilization of a bump can result in either a traveling pulse or a spatially localized breather.

  16. RED GIANT BRANCH BUMP BRIGHTNESS AND NUMBER COUNTS IN 72 GALACTIC GLOBULAR CLUSTERS OBSERVED WITH THE HUBBLE SPACE TELESCOPE

    SciTech Connect

    Nataf, David M.; Gould, Andrew P.; Pinsonneault, Marc H.; Udalski, Andrzej

    2013-04-01

    We present the broadest and most precise empirical investigation of red giant branch bump (RGBB) brightness and number counts ever conducted. We implement a new method and use data from two Hubble Space Telescope globular cluster (GC) surveys to measure the brightness and star counts of the RGBB in 72 GCs. The median measurement precision is 0.018 mag in the brightness and 31% in the number counts, respectively, reaching peak precision values of 0.005 mag and 10%. The position of the main-sequence turnoff and the number of horizontal branch stars are used as comparisons where appropriate. Several independent scientific conclusions are newly possible with our parameterization of the RGBB. Both brightness and number counts are shown to have second parameters in addition to their strong dependence on metallicity. The RGBBs are found to be anomalous in the GCs NGC 2808, 5286, 6388, and 6441, likely due to the presence of multiple populations. Finally, we use our empirical calibration to predict the properties of the Galactic bulge RGBB. The updated RGBB properties for the bulge are shown to differ from the GC-calibrated prediction, with the former having lower number counts, a lower brightness dispersion, and a brighter peak luminosity than would be expected from the latter. This discrepancy is well explained by the Galactic bulge having a higher helium abundance than expected from GCs, {Delta}Y {approx} +0.06 at the median metallicity.

  17. Stress investigation on the rolling tires across the speed bump using finite element method

    NASA Astrophysics Data System (ADS)

    Hidayat, Royan; Pranoto, Sarwo Edy; Tauviqirrahman, Mohammad; Bayuseno, Athanasius P.

    2016-04-01

    The interaction between road surface and tire on a vehicle may strongly determine the vehicle's stability. This study was conducted to find out the stress distribution as a result of pressure on the tires rolling across the speed bumps. This study used Abaqus software to simulate the movement of the tire, which rolls across the speed bump to determine the stress distribution that may occur. The tire component material used was a full path rubber on a speed bump. For the boundary conditions of the study, it was assumed that the tires had load variations as much as 2 kN, 6 kN, 10 kN, as well as pressure variations as much as 17 Psi, 30 Psi, 40 Psi. The tires were then rolled 8 km/h crossing the speed bump. Modeling speed bumps also varied i.e. the first variation of speed bumps that have a height of 50 mm with a width of 250 mm, the second variation of height 75 mm with a width of 300 mm, and a third variation of height 100 mm with a width of 400 mm. The simulation was done by giving the tire pressures as much as 17 Psi, 30 Psi, 40 Psi and loads as much as 2 kN, 6 kN, 10 kN. Further, the tires were rolled three times. It was rolled crossing the first speed bump, the second, and the third, respectively. Results showed stress distribution's fig and graphs. From the analysis results and simulation, it was shown that the greater the load received by the tires, the higher stress they produced.

  18. Development of an Indium bump bond process for silicon pixel detectors at PSI

    NASA Astrophysics Data System (ADS)

    Broennimann, Ch.; Glaus, F.; Gobrecht, J.; Heising, S.; Horisberger, M.; Horisberger, R.; Kästli, H. C.; Lehmann, J.; Rohe, T.; Streuli, S.

    2006-09-01

    The hybrid pixel detectors used in the high-energy physics experiments currently under construction use a vertical connection technique, the so-called bump bonding. As the pitch below 100 μm, required in these applications, cannot be fulfilled with standard industrial processes (e.g. the IBM C4 process), an in-house bump bond process using reflowed indium bumps was developed at PSI as part of the R&D for the CMS-pixel detector. The bump deposition on the sensor is performed in two subsequent lift-off steps. As the first photolithographic step a thin under bump metalization (UBM) is sputtered onto bump pads. It is wettable by indium and defines the diameter of the bump. The indium is evaporated via a second photolithographic step with larger openings and is reflowed afterwards. The height of the balls is defined by the volume of the indium. On the readout chip only one photolithographic step is carried out to deposit the UBM and a thin indium layer for better adhesion. After mating both parts a second reflow is performed for self-alignment and obtaining high mechanical strength. For the placement of the chips a manual and an automatic machine were constructed. The former is very flexible in handling different chip and module geometries but has a limited throughput while the latter features a much higher grade of automatization and is therefore much more suited for producing hundreds of modules with a well-defined geometry. The reliability of this process was proven by the successful construction of the PILATUS detector. The construction of PILATUS 6M (60 modules) and the CMS pixel barrel (roughly 800 modules) has started in early 2006.

  19. Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer

    DOEpatents

    Chiu, Rong-Shi Paul; Hasz, Wayne Charles; Johnson, Robert Alan; Lee, Ching-Pang; Abuaf, Nesim

    2002-01-01

    An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.

  20. A comparison of new thick photoresists for solder bumping

    NASA Astrophysics Data System (ADS)

    Flack, Warren W.; Nguyen, Ha-Ai; Neisser, Mark; Sison, Ernesto; Lu, Ping Hung; Plass, Bob; Makii, Toshimichi; Murakami, Yoshio

    2005-05-01

    The performance requirements for ultra-thick photoresists are rapidly increasing with the dramatic growth in lithographic applications that require electroplating processes. Two of the main applications for ultra-thick photoresists are advanced packaging and nanotechnology (MEMS). Flipchip packaging has become widely adopted to address electrical device performance and chip form factor considerations. The growth in the nanotechnology market is driven by a wide range of products, which include accelerometers, ink jet print heads, biomedical sensors and optical switches. The requirements of thick photoresists for solder electroplating are significantly different from typical thin photoresists used in front end of line applications. As the photoresist becomes thicker, processing times increase for many process steps. Photospeed gets slower due to the requirements for more chemical reactions per area of coating. Coating uniformity and edge bead control also become more difficult as photoresist films get thicker and time delay issues between process steps can arise. This result has led to the requirement for special photoresist formulations for thick photoresist films. These are traditionally positive tone DNQ-Novolak materials such as AZ 50XT. Such materials can be designed to work for a particular range of thicknesses, but as the desired thicknesses increases the processing times can become very long for high volume manufacturing. Many new bumping schemes require photoresists in a 60 to 70 μm thickness range. While DNQ-Novolak chemistry can work, there is a desire for faster alternatives to improve total cost of ownership (COO) of the lithography cell. In order to have fast photospeeds and reasonable processing times a chemistry that is very photo efficient is needed. Negative tone cross linking chemistries, which can give tens of thousands of chemical events for one photochemical event, provide excellent photospeed and process times. Positive tone chemically

  1. On the Application of Contour Bumps for Transonic Drag Reduction(Invited)

    NASA Technical Reports Server (NTRS)

    Milholen, William E., II; Owens, Lewis R.

    2005-01-01

    The effect of discrete contour bumps on reducing the transonic drag at off-design conditions on an airfoil have been examined. The research focused on fully-turbulent flow conditions, at a realistic flight chord Reynolds number of 30 million. State-of-the-art computational fluid dynamics methods were used to design a new baseline airfoil, and a family of fixed contour bumps. The new configurations were experimentally evaluated in the 0.3-m Transonic Cryogenic Tunnel at the NASA Langley Research center, which utilizes an adaptive wall test section to minimize wall interference. The computational study showed that transonic drag reduction, on the order of 12% - 15%, was possible using a surface contour bump to spread a normal shock wave. The computational study also indicated that the divergence drag Mach number was increased for the contour bump applications. Preliminary analysis of the experimental data showed a similar contour bump effect, but this data needed to be further analyzed for residual wall interference corrections.

  2. DIAGNOSTICS ON THE SOURCE PROPERTIES OF A TYPE II RADIO BURST WITH SPECTRAL BUMPS

    SciTech Connect

    Feng, S. W.; Chen, Y.; Kong, X. L.; Li, G.; Song, H. Q.; Feng, X. S.; Guo, Fan

    2013-04-10

    In recent studies, we proposed that source properties of type II radio bursts can be inferred through a causal relationship between the special shape of the type II dynamic spectrum (e.g., bump or break) and simultaneous extreme ultraviolet (EUV)/white light imaging observations (e.g., CME-shock crossing streamer structures). As a further extension of these studies, in this paper we examine the coronal mass ejection (CME) event on 2007 December 31 associated with a multiple type II radio burst. We identify the presence of two spectral bump features on the observed dynamic spectrum. By combining observational analyses of the radio spectral observations and the EUV-white light imaging data, we conclude that the two spectral bumps result from a CME-shock propagating across dense streamers on the southern and northern sides of the CME. It is inferred that the corresponding two type II emissions originate separately from the two CME-shock flanks where the shock geometries are likely quasi-perpendicular or oblique. Since the emission lanes are bumped as a whole within a relatively short time, it suggests that the type II radio bursts with bumps of this study are emitted from spatially confined sources (with a projected lateral dimension smaller than 0.05-0.1 R{sub Sun} at a fundamental frequency level of 20-30 MHz).

  3. Fabrication of Back-Side Illuminated Complementary Metal Oxide Semiconductor Image Sensor Using Compliant Bump

    NASA Astrophysics Data System (ADS)

    Naoya Watanabe,; Isao Tsunoda,; Takayuki Takao,; Koichiro Tanaka,; Tanemasa Asano,

    2010-04-01

    We fabricated a back-side illuminated (BSI) complementary metal oxide semiconductor (CMOS) image sensor in which a very-thin BSI photodiode array chip was stacked on a CMOS read-out circuit chip by compliant bumps. Cone-shaped bumps made of Au were prepared as the compliant bumps. The base diameter was 10-12 μm and the height was 9-10 μm. To fabricate the BSI CMOS image sensor, we developed a novel thin-chip assembly process. The key features of the process are as follows: preparation of a photodiode array wafer and a CMOS read-out circuit wafer, Au cone bump formation, bonding to support glass, thinning of the photodiode array wafer to 21 μm, through silicon via (TSV) formation using Cu electroplating, formation of back-side electrodes, transfer of the photodiode array wafer to a polymer support tape, dicing of the photodiode array wafer, separation of support tape, formation of Ni-Au bumps, dicing of CMOS read-out circuit wafer, and three-dimensional (3D) chip-stacking. The BSI CMOS image sensor thus fabricated has the following specifications: number of active pixels is 16,384 (128 × 128), photodiode size is approximately 18 μm square, photodiode pitch is 24 μm, and fill factor is approximately 55%. No defects were observed in the obtained image frames.

  4. Fabrication of Back-Side Illuminated Complementary Metal Oxide Semiconductor Image Sensor Using Compliant Bump

    NASA Astrophysics Data System (ADS)

    Watanabe, Naoya; Tsunoda, Isao; Takao, Takayuki; Tanaka, Koichiro; Asano, Tanemasa

    2010-04-01

    We fabricated a back-side illuminated (BSI) complementary metal oxide semiconductor (CMOS) image sensor in which a very-thin BSI photodiode array chip was stacked on a CMOS read-out circuit chip by compliant bumps. Cone-shaped bumps made of Au were prepared as the compliant bumps. The base diameter was 10-12 µm and the height was 9-10 µm. To fabricate the BSI CMOS image sensor, we developed a novel thin-chip assembly process. The key features of the process are as follows: preparation of a photodiode array wafer and a CMOS read-out circuit wafer, Au cone bump formation, bonding to support glass, thinning of the photodiode array wafer to 21 µm, through silicon via (TSV) formation using Cu electroplating, formation of back-side electrodes, transfer of the photodiode array wafer to a polymer support tape, dicing of the photodiode array wafer, separation of support tape, formation of Ni-Au bumps, dicing of CMOS read-out circuit wafer, and three-dimensional (3D) chip-stacking. The BSI CMOS image sensor thus fabricated has the following specifications: number of active pixels is 16,384 (128 ×128), photodiode size is approximately 18 µm square, photodiode pitch is 24 µm, and fill factor is approximately 55%. No defects were observed in the obtained image frames.

  5. Life scripts for emotionally charged autobiographical memories: A cultural explanation of the reminiscence bump.

    PubMed

    Haque, Shamsul; Hasking, Penelope A

    2010-10-01

    Two studies examined the ability of the life script account to explain the reminiscence bump for emotionally charged autobiographical memories among Malaysian participants. In Study 1 volunteers, aged 50-90 years, participated in a two-phased task. In the first phase, participants estimated the timing of 11 life events (both positive and negative) that may occur in a prototypical life course within their own culture. Two weeks later the participants retrieved the same set of events from their lives and reported how old they were when those events occurred. In the second study 92 undergraduate students produced life scripts for the same 11 events. The findings revealed reminiscence bumps in both life script and retrieval curves for the memories judged happiest, most important, most in love, and most jealous. A reminiscence bump was also noted for success, although this was later in the lifespan than other reminiscence bumps. It was suggested that the life scripts can be used as an alternative account for the reminiscence bump, for highly positive and occasionally for negative autobiographical memories. PMID:20803371

  6. A 90 GHz Amplifier Assembled Using a Bump-Bonded InP-Based HEMT

    NASA Technical Reports Server (NTRS)

    Pinsukanjana, Paul R.; Samoska, Lorene A.; Gaier, Todd C.; Smith, R. Peter; Ksendzov, Alexander; Fitzsimmons, Michael J.; Martin, Suzanne C.

    1998-01-01

    We report on the performance of a novel W-band amplifier fabricated utilizing very compact bump bonds. We bump-bonded a high-speed, low-noise InP high electron mobility transistor (HEMT) onto a separately fabricated passive circuit having a GaAs substrate. The compact bumps and small chip size were used for efficient coupling and maximum circuit design flexibility. This new quasi-monolithic millimeter-wave integrated circuit (Q-MMIC) amplifier exhibits a peak gain of 5.8 dB at approx. 90 GHz and a 3 dB bandwidth of greater than 25%. To our knowledge, this is the highest frequency amplifier assembled using bump-bonded technology. Our bump-bonding technique is a useful alternative to the high cost of monolithic millimeter-wave integrated circuits (MMIC's). Effects of the bumps on the circuit appear to be minimal. We used the simple matching circuit for demonstrating the technology - future circuits would have all of the elements (resistors, via holes, bias lines, etc.) included 'in conventional MMIC's. Our design in different from other investigators' efforts in that the bumps are only 8 microns thick by 15 microns wide. The bump sizes were sufficiently small that the devices, originally designed for W-band hybrid circuits, could be bonded without alteration. Figure 3 shows the measured and simulated magnitude of S-parameters from 85-120 GHz, of the InP HEMT bump-bonded to the low noise amplifier (LNA) passive. The maximum gain is 5.8 dB at approx. 90 GHz, and gain extends to 117 GHz. Measurement of a single device (without matching networks) shows approx. 1 dB of gain at 90 GHz. The measured gain of the amplifier agrees well with the design in the center of the measurement band, and the agreement falls off at the band edges. Since no accommodation for the bump-bonding parasitics was made in the design, the result implies that the parasitic elements associated with the bonding itself do not dominate the performance of the LNA circuit. It should be noted that this

  7. Rayleigh-Taylor growth of bumps on inertial confinement fusion targets: Final report

    SciTech Connect

    Montierth, L.; Morse, R.

    1987-10-01

    The purpose of this paper is to demonstrate a technique for determining the spatial and temporal evolution of surface imperfections which are composed of a spectrum of wavelengths using results from these linear studies. These surface imperfections, or bumps, may result from target fabrication techniques or may be intentionally inscribed on the target's surface for use in instability experiments. For the purposes of this paper we assume a particular spatial shape for the bump although the technique is applicable to other bump shapes. While the results are only valid during the linear phase of the instability, estimates can be obtained for predicting when the transition to nonlinear behavior might occur. 6 refs., 28 figs.

  8. Method to Improve Indium Bump Bonding via Indium Oxide Removal Using a Multi-Step Plasma Process

    NASA Technical Reports Server (NTRS)

    Greer, H. Frank (Inventor); Jones, Todd J. (Inventor); Vasquez, Richard P. (Inventor); Hoenk, Michael E. (Inventor); Dickie, Matthew R. (Inventor); Nikzad, Shouleh (Inventor)

    2012-01-01

    A process for removing indium oxide from indium bumps in a flip-chip structure to reduce contact resistance, by a multi-step plasma treatment. A first plasma treatment of the indium bumps with an argon, methane and hydrogen plasma reduces indium oxide, and a second plasma treatment with an argon and hydrogen plasma removes residual organics. The multi-step plasma process for removing indium oxide from the indium bumps is more effective in reducing the oxide, and yet does not require the use of halogens, does not change the bump morphology, does not attack the bond pad material or under-bump metallization layers, and creates no new mechanisms for open circuits.

  9. Precision translator

    DOEpatents

    Reedy, Robert P.; Crawford, Daniel W.

    1984-01-01

    A precision translator for focusing a beam of light on the end of a glass fiber which includes two turning fork-like members rigidly connected to each other. These members have two prongs each with its separation adjusted by a screw, thereby adjusting the orthogonal positioning of a glass fiber attached to one of the members. This translator is made of simple parts with capability to keep adjustment even in condition of rough handling.

  10. Precision translator

    DOEpatents

    Reedy, R.P.; Crawford, D.W.

    1982-03-09

    A precision translator for focusing a beam of light on the end of a glass fiber which includes two turning fork-like members rigidly connected to each other. These members have two prongs each with its separation adjusted by a screw, thereby adjusting the orthogonal positioning of a glass fiber attached to one of the members. This translator is made of simple parts with capability to keep adjustment even in condition of rough handling.

  11. Wall pressure fluctuations and flow-induced noise in a turbulent boundary layer over a bump

    NASA Astrophysics Data System (ADS)

    Kim, Joongnyon; Sung, Hyung Jin

    2006-07-01

    Direct numerical simulations of a turbulent boundary layer over a bump were performed to examine the effects of surface longitudinal curvature on wall pressure fluctuations (p_{w}) and flow-induced noise. Turbulence statistics and frequency spectra were obtained to elucidate the response of wall pressure fluctuations to the longitudinal curvature and to the corresponding pressure gradient. Wall pressure fluctuations were significantly enhanced near the trailing edge of the bump, where the boundary layer was subjected to a strong adverse pressure gradient. Large-scale structures in the distribution of wall pressure fluctuations were observed to grow rapidly near the trailing edge of the bump and convect downstream. Acoustic sources of the Lighthill equations were investigated in detail at various longitudinal surface curvatures. The acoustic sources (S) were highest near the trailing edge of the bump, where the root mean square wall pressure fluctuations were greatest. The maximum correlation coefficient between p_{w} and S was located just above the location of maximum wall pressure fluctuations. Far-field acoustic density fluctuations were computed using the Lighthill acoustic analogy. We found that the surface dipole is dominant in the total acoustic field. The contribution of the volume quadrupoles to the total acoustic field gradually increases with increasing radius of the surface curvature (delta/ R).

  12. Qualification test report bump protection hat (subassembly of T020/M509 head protective assembly)

    NASA Technical Reports Server (NTRS)

    Willis, D. B.

    1972-01-01

    The bump protection hat (BPH) was subjected to impact testing in which it underwent three impacts at 35 foot-pounds of energy. The impacts generated stress cracks, but no penetration. All impacts resulted in deflections of less than one-half inch. It was shown that the BPH is qualified for Skylab and the rescue vehicle.

  13. Photogrammetric 3d Acquisition and Analysis of Medicamentous Induced Pilomotor Reflex ("goose Bumps")

    NASA Astrophysics Data System (ADS)

    Schneider, D.; Hecht, A.

    2016-06-01

    In a current study at the University Hospital Dresden, Department of Neurology, the autonomous function of nerve fibres of the human skin is investigated. For this purpose, a specific medicament is applied on a small area of the skin of a test person which results in a local reaction (goose bumps). Based on the extent of the area, where the stimulation of the nerve fibres is visible, it can be concluded how the nerve function of the skin works. The aim of the investigation described in the paper is to generate 3D data of these goose bumps. Therefore, the paper analyses and compares different photogrammetric surface measurement techniques in regard to their suitability for the 3D acquisition of silicone imprints of the human skin. Furthermore, an appropriate processing procedure for analysing the recorded point cloud data is developed and presented. It was experimentally proven that by using (low-cost) photogrammetric techniques medicamentous induced goose bumps can be acquired in three dimensions and can be analysed almost fully automatically from the perspective of medical research questions. The relative accuracy was determined with 1% (RMSE) of the area resp. the volume of an individual goose bump.

  14. Ultraviolet photometry from the Orbiting Astronomical Observatory. XX - The ultraviolet extinction bump

    NASA Technical Reports Server (NTRS)

    Savage, B. D.

    1975-01-01

    Ultraviolet extinction bumps are investigated in the interstellar extinction curves between 1800 and 3600 A for 36 stars which have (B-V) excesses ranging from 0.03 to 0.55 and are mostly confined to the brighter OB associations distributed along the galactic plane. Each extinction curve is found to have a broad bump which peaks near 2175 A and whose position and profile appear to be constant among all the stars. It is shown that the bump is probably interstellar in origin and that the constancy of its position and shape places such severe restrictions on grain geometrical parameters that classical scattering theory cannot be used to explain the feature unless the dust grains in widely separated regions of space and with very different physical conditions are assumed to have nearly identical size and shape distributions. Three extinction curves which extend to 1100 A are examined and found to have the same general characteristics as the others. Several extinction curves are analyzed for fine structure, but no convincing evidence is found in the present interval. Some processes are discussed which may be responsible for the bumps.

  15. Thermohydrodynamics analysis on the mechanism of bump formation in laser texturing

    NASA Astrophysics Data System (ADS)

    Ohmura, Etsuji; Murayama, Rina; Miyamoto, Isamu

    2000-11-01

    Laser texturing on a hard disk for a computer has been already used practically, but the mechanism of bump formation has not been elucidated yet. The purpose of this study is to elucidate the mechanism of bump formation in laser texturing by thermohydrodynamics analysis. Latent heat of evaporation, movement of gas and liquid interface, evaporation recoil pressure, Marangoni force that depends on temperature gradient and the surface tension are considered. The VOF (Volume of Fluid) method is used for the analysis of behavior of the free surface. Obtained results are as follows : (1) The downward flow is generated in the molten pool by the evaporation recoil pressure, and then it induces the outward flow in the radial direction. (2) After laser irradiation is stopped, the downward flow at the center of the molten pool and the outward flow in the radial direction are kept. Therefore, the center of the molten pool is lowered and the surface rises around the hole, that is, a bump is formed. (3) When the temperature coefficient of surface tension is negative, Marangoni force is most effective to the surface rise when the resolidification starts outside of the bump.

  16. Precise Extraction of the Neutron Magnetic Form Factor from Quasi-elastic 3He(pol)(e(pol),e') at Q^2 = 0.1-0.6 (GeV/c)^2

    SciTech Connect

    Jens-ole Hansen; Brian Anderson; Leonard Auerbach; Todd Averett; William Bertozzi; Tim Black; John Calarco; Lawrence Cardman; Gordon Cates; Zhengwei Chai; Jiang-Ping Chen; Seonho Choi; Eugene Chudakov; Steve Churchwell; G Corrado; Christopher Crawford; Daniel Dale; Alexandre Deur; Pibero Djawotho; Dipangkar Dutta; John Finn; Haiyan Gao; Ronald Gilman; Oleksandr Glamazdin; Charles Glashausser; Walter Gloeckle; Jacek Golak; Javier Gomez; Viktor Gorbenko; F. Hersman; Douglas Higinbotham; Richard Holmes; Calvin Howell; Emlyn Hughes; Thomas Humensky; Sebastien Incerti; Piotr Zolnierczuk; Cornelis De Jager; John Jensen; Xiaodong Jiang; Cathleen Jones; Mark Jones; R Kahl; H Kamada; A Kievsky; Ioannis Kominis; Wolfgang Korsch; Kevin Kramer; Gerfried Kumbartzki; Michael Kuss; Enkeleida Lakuriqi; Meihua Liang; Nilanga Liyanage; John LeRose; Sergey Malov; Demetrius Margaziotis; Jeffery Martin; Kathy McCormick; Robert McKeown; Kevin McIlhany; Zein-Eddine Meziani; Robert Michaels; Greg Miller; Joseph Mitchell; Sirish Nanda; Emanuele Pace; Tina Pavlin; Gerassimos Petratos; Roman Pomatsalyuk; David Pripstein; David Prout; Ronald Ransome; Yves Roblin; Marat Rvachev; Giovanni Salme; Michael Schnee; Charles Seely; Taeksu Shin; Karl Slifer; Paul Souder; Steffen Strauch; Riad Suleiman; Mark Sutter; Bryan Tipton; Luminita Todor; M Viviani; Branislav Vlahovic; John Watson; Claude Williamson; H Witala; Bogdan Wojtsekhowski; Feng Xiong; Wang Xu; Jen-chuan Yeh

    2006-05-05

    We have measured the transverse asymmetry A{sub T'} in the quasi-elastic {sup 3}/rvec He/(/rvec e/,e') process with high precision at Q{sup 2}-values from 0.1 to 0.6 (GeV/c){sup 2}. The neutron magnetic form factor G{sub M}{sup n} was extracted at Q{sup 2}-values of 0.1 and 0.2 (GeV/c){sup 2} using a non-relativistic Faddeev calculation which includes both final-state interactions (FSI) and meson-exchange currents (MEC). Theoretical uncertainties due to the FSI and MEC effects were constrained with a precision measurement of the spin-dependent asymmetry in the threshold region of {sup 3}/rvec He/(/rvec e/,e'). We also extracted the neutron magnetic form factor G{sub M}{sup n} at Q{sup 2}-values of 0.3 to 0.6 (GeV/c){sup 2} based on Plane Wave Impulse Approximation calculations.

  17. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    SciTech Connect

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D'Angelo, A.; Dashyan, N.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Livingston, K.; Lu, H. Y.; Mayer, M.; MacGregor, I. J. D.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Net, L. A.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Simonyan, A.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Voutier, E.; Walford, N. K.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-11-02

    In this study, we present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron (15ND3) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry Ad1 and the polarized structure function gd1 were extracted over a wide kinematic range (0.05 GeV2 < Q2 < 5 GeV2 and 0.9 GeV < W < 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions An1 and g1n of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x, a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the Operator Product Expansion.

  18. Measurement of the Ratio {sigma}{sub tt}/{sigma}{sub Z/{gamma}}{sup *}{sub {yields}ll} and Precise Extraction of the tt Cross Section

    SciTech Connect

    Aaltonen, T.; Mehtala, P.; Orava, R.; Osterberg, K.; Saarikko, H.; Remortel, N. van; Adelman, J.; Brubaker, E.; Fedorko, W. T.; Grosso-Pilcher, C.; Hurwitz, M.; Ketchum, W.; Kim, Y. K.; Krop, D.; Kwang, S.; Lee, H. S.; Schmidt, M. A.; Shiraishi, S.; Shochet, M.; Tang, J.

    2010-07-02

    We report a measurement of the ratio of the tt to Z/{gamma}* production cross sections in {radical}(s)=1.96 TeV pp collisions using data corresponding to an integrated luminosity of up to 4.6 fb{sup -1}, collected by the CDF II detector. The tt cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/{gamma}{sup *{yields}}ll cross section predicted by the standard model, the extracted tt cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result {sigma}{sub tt}=7.70{+-}0.52 pb, for a top-quark mass of 172.5 GeV/c{sup 2}.

  19. The relocation bump: Memories of middle adulthood are organized around residential moves.

    PubMed

    Enz, Karalyn F; Pillemer, David B; Johnson, Kenneth M

    2016-08-01

    The lifetime temporal distribution of older adults' autobiographical memories peaks during the transitional period of late adolescence and early adulthood, a phenomenon known as the reminiscence bump. This age-specific memory enhancement suggests that transitions may provide a more general organizing structure for autobiographical memory. To test this hypothesis, we examined how older adults' memories of events that occurred between the ages of 40 and 60 were distributed around residential relocations occurring within this same time frame. The temporal distribution of memories showed a marked relocation bump around the age of the most important residential move. Although previous research has focused on the negative effects of relocation, the current findings suggest that transitions could have a positive effect on autobiographical memory. (PsycINFO Database Record PMID:27454038

  20. Design, modeling and test of a novel speed bump energy harvester

    NASA Astrophysics Data System (ADS)

    Todaria, Prakhar; Wang, Lirong; Pandey, Abhishek; O'Connor, James; McAvoy, David; Harrigan, Terence; Chernow, Barbara; Zuo, Lei

    2015-04-01

    Speed bumps are commonly used to control the traffic speed and to ensure the safety of pedestrians. This paper proposes a novel speed bump energy harvester (SBEH), which can generate large-scale electrical energy up to several hundred watts when the vehicle drives on it. A unique design of the motion mechanism allows the up-and-down pulse motion to drive the generator into unidirectional rotation, yielding time times more energy than the traditional design. Along with the validation of energy harvesting, this paper also addresses the advantages of this motion mechanism over the traditional design, using physical modeling and simulation. Up to 200 watts electrical peak power in one phase of three-phase generator during in-field test can be regenerated when a sedan passage car passes through the SBEH prototype at 2 km/h.

  1. Detection of bump-on-tail reduced electron velocity distributions at the electron foreshock boundary

    NASA Technical Reports Server (NTRS)

    Fitzenreiter, R. J.; Klimas, A. J.; Scudder, J. D.

    1984-01-01

    Reduced velocity distributions are derived from three-dimensional measurements of the velocity distribution of electrons in the 7 to 500 eV range in the electron foreshock. Bump-on-tail reduced distributions are presented for the first time at the foreshock boundary consistent with Filbert and Kellogg's proposed time-of-flight mechanism for generating the electron beams. In a significant number of boundary crossings, bump-on-tail reduced distributions were found in consecutive 3 sec measurements made 9 sec apart. It is concluded that, although the beams are linearly unstable to plasma waves according to the Penrose criterion, they persist on a time scale of 3 to 15 sec.

  2. Room-Temperature Cu Microjoining with Ultrasonic Bonding of Cone-Shaped Bump

    NASA Astrophysics Data System (ADS)

    Qiu, Lijing; Ikeda, Akihiro; Noda, Kazuhiro; Nakai, Seiya; Asano, Tanemasa

    2013-04-01

    Room-temperature Cu-Cu bonding was realized by applying ultrasonic vibration together with compression force to the bonding of a cone-shaped bump. The size of the bump was about 10 µm. The connection pitch was 20 µm. Mechanical characterization showed that the bonding strength increases with vibration amplitude and depends on the thickness of the counter electrode made of Cu. The thickness dependence of the bonding strength was found to be caused by an increase in the surface roughness of the counter electrode. It was shown that the bonding strength meets the requirement from application to products. Electrical characterization using a daisy-chain connection test demonstrated that more than 10,000 pins on a chip can be connected with a sufficiently low resistance.

  3. CFD-Predicted Tile Heating Bump Factors Due to Tile Overlay Repairs

    NASA Technical Reports Server (NTRS)

    Lessard, Victor R.

    2006-01-01

    A Computational Fluid Dynamics investigation of the Orbiter's Tile Overlay Repair (TOR) is performed to assess the aeroheating Damage Assessment Team's (DAT) existing heating correlation method for protuberance interference heating on the surrounding thermal protection system. Aerothermodynamic heating analyses are performed for TORs at the design reference damage locations body points 1800 and 1075 for a Mach 17.9 and a=39deg STS-107 flight trajectory point with laminar flow. Six different cases are considered. The computed peak heating bump factor on the surrounding tiles are below the DAT's heating bump factor values for smooth tile cases. However, for the uneven tiles cases the peak interference heating is shown to be considerably higher than the existing correlation prediction.

  4. Multipole error analysis using local 3-bump orbit data in Fermilab Recycler

    SciTech Connect

    Yang, M.J.; Xiao, M.; /Fermilab

    2005-05-01

    The magnetic harmonic errors of the Fermilab Recycler ring were examined using circulating beam data taken with closed local orbit bumps. Data was first parsed into harmonic orbits of first, second, and third order. Each of which was analyzed for sources of magnetic errors of corresponding order. This study was made possible only with the incredible resolution of a new BPM system that was commissioned after June of 2003.

  5. Effect of overshooting mixing below the base of the convective envelope on the RGB bump

    NASA Astrophysics Data System (ADS)

    Li, Yan

    2015-08-01

    When a low mass star evolves up along the red giant branch (RGB), it will develop much more extensive convection in its envelope. Such envelope convection penetrates rapidly inward into the stellar interior, and finally results in a composition discontinuity when it develops into the chemical gradient region. Subsequently, when the out-moving hydrogen burning-shell encounters the newly-formed composition discontinuity, the star will develops the so-called RGB bump on the HR diagram. Therefore, comparisons of characteristics of the RGB bump are crucial for the overshooting mixing below the base of the stellar convective envelope.In order to treat overshooting convection below the base of the convective envelope, we used the k-omega model of Li (2012) in RGB models of a 1Msun star. We solved equations of the k-omega model in the stellar envelope, and then found that the turbulent kinetic energy and the frequency of turbulence decay in the overshooting region according approximately to power laws of pressure. The decaying indices are found to be sensitive to the parameters of the k-omega model. We adopted a modified overshooting mixing model of Zhang (2013) to investigate the overshooting mixing below the base of the convection zone. We found that the RGB bump appears at a significantly lower luminosity when using the k-omega model than when using the standard mixing-length theory, and its duration is also considerably reduced. Due to extra dredge-up effect of the overshooting mixing, we obtained a little hotter red giant branch using the k-omega model than the one using the standard MLT. We found that the position and duration of the RGB bump sensitively depend on the decaying law of turbulence in the overshooting region. These predictions could be good candidates for asteroseismology of RGB stars.

  6. Beta-Beat Correction Using Strong Sextupole Bumps in PEP-II

    SciTech Connect

    Yocky, G.; /SLAC

    2007-05-18

    A method for correcting lattice beta mismatches has been developed for the PEP-II collider using orbit offsets in strong sextupoles. The solution is first predicted in the MAD program by modeling closed orbit bumps in the plane of correction at the sextupoles strongest in that plane. The derived solution is then tested in the machine to confirm prediction, and finally dialed into the machine under high-current conditions.

  7. GIANT X-RAY BUMP IN GRB 121027A: EVIDENCE FOR FALL-BACK DISK ACCRETION

    SciTech Connect

    Wu Xuefeng; Hou Shujin; Lei Weihua E-mail: leiwh@hust.edu.cn

    2013-04-20

    A particularly interesting discovery in observations of GRB 121027A is that of a giant X-ray bump detected by the Swift/X-Ray Telescope. The X-ray afterglow re-brightens sharply at {approx}10{sup 3} s after the trigger by more than two orders of magnitude in less than 200 s. This X-ray bump lasts for more than 10{sup 4} s. It is quite different from typical X-ray flares. In this Letter we propose a fall-back accretion model to interpret this X-ray bump within the context of the collapse of a massive star for a long-duration gamma-ray burst. The required fall-back radius of {approx}3.5 Multiplication-Sign 10{sup 10} cm and mass of {approx}0.9-2.6 M{sub Sun} imply that a significant part of the helium envelope should survive through the mass loss during the last stage of the massive progenitor of GRB 121027A.

  8. BUMP: a FORTRAN program for identifying dose-response curves subject to downturns.

    PubMed

    Simpson, D G; Dallal, G E

    1989-02-01

    BUMP is a FORTRAN implementation of a modified Jonckheere-Terpstra test, proposed by Simpson and Margolin, to test nonparametrically for a dose-response curve when a downturn is possible at high doses. The Jonckheere-Terpstra statistic is commonly used to test for increasing or decreasing trends in dose-response relationships. In many experimental settings, however, a test agent has more than one effect, and a "bump"-shaped dose-response can occur. For instance, increasing the concentration of a certain nutrient on a petri dish may increase the growth rate at low doses yet decrease the growth rate at high doses because of toxicity. The modified test allows one to assess the significance of the initial increase in the dose-response curve and yet to minimize the effect on the conclusions of any downturn at higher doses. A complete system which operates directly on SYSTAT/MYSTAT files is available for the IBM-PC and compatibles; it includes a utility which converts ASCII data files to the SYSTAT/MYSTAT format. The FORTRAN 77 source code is available for those who would like to run BUMP on other machines. PMID:2914424

  9. Experimental and Numerical Verification of Fatigue Life Estimation for Solder Bumps

    NASA Astrophysics Data System (ADS)

    Mukai, Minoru; Takahashi, Hiroyuki; Kawakami, Takashi; Takahashi, Kuniaki; Iwasaki, Ken; Kishimoto, Kikuo; Shibuya, Toshikazu

    Fatigue life estimation of solder bumps is one of the most critical technologies for the development of ball grid array packages. In this study, mechanical fatigue tests were carried out using Sn63-Pb37 solder bump specimens. The cracks were initiated along the entire circumference in the vicinity of the interface. The fatigue life estimation of the solder bumps was performed based on the elastic-creep finite element method (FEM) analysis. It was clear that the strain concentration region coincides with the crack initiation site. The estimation result for the crack initiation was in good agreement with the experimental results. The results reconfirmed that it was desirable to employ the equivalent creep strain range occurring at a distance of 50 μm from the singularity point. The life ratio, which provides the quantitative correlation between the crack initiation and the ultimate fracture, was determined from the experimental results. The number of cycles to the fatal failure can be roughly estimated by multiplying the analytical estimation results for the crack initiation by this life ratio. This simple estimation of fatal failure may well be of practical use in actual ball grid array (BGA) design for thermal load conditions.

  10. Blue wings and bumps via Fermi-like acceleration of Ly α photons across shocks

    NASA Astrophysics Data System (ADS)

    Chung, Andrew S.; Dijkstra, Mark; Ciardi, Benedetta; Gronke, Max

    2016-01-01

    We explore the impact of Fermi-like acceleration of Lyman α (Ly α) photons across shock fronts on the observed Ly α spectral line shape. We first confirm the result of Neufeld & McKee (1988) that this mechanism gives rise to extended blue wings which may have been observed in some radio galaxies. Our Monte Carlo radiative transfer calculations further show that in a minor modification of the shell model, in which we add an additional static shell of hydrogen, this process can naturally explain the small blue bumps observed in a subset of Ly α-emitting galaxies, which have been difficult to explain with conventional shell models. Blue bumps can be produced with an additional column density of static hydrogen as small as N^static_{H I} ≪ N^shell_{H I}, and typically occur at roughly the outflow velocity of the shell. In our model the spectra of so-called blue-bump objects might reflect an evolutionary stage in which the outflows regulating the escape of Ly α photons are still engulfed within a static interstellar medium.

  11. Development of a reliable analytical method for the precise extractive spectrophotometric determination of osmium(VIII) with 2-nitrobenzaldehydethiocarbohydrazone: Analysis of alloys and real sample.

    PubMed

    Zanje, Sunil B; Kokare, Arjun N; Suryavanshi, Vishal J; Waghmode, Duryodhan P; Joshi, Sunil S; Anuse, Mansing A

    2016-12-01

    The proposed method demonstrates that the osmium(VIII) forms complex with 2-NBATCH from 0.8molL(-1) HCl at room temperature. The complex formed was extracted in 10mL of chloroform with a 5min equilibration time. The absorbance of the red colored complex was measured at 440nm against the reagent blank. The Beer's law was obeyed in the range of 5-25μgmL(-1), the optimum concentration range was 10-20μgmL(-1) of osmium(VIII) as evaluated by Ringbom's plot. Molar absorptivity and Sandell's sensitivity of osmium(VIII)-2NBATCH complex in chloroform is 8.94×10(3)Lmol(-1)cm(-1) and 0.021μgcm(-2), respectively. The composition of osmium(VIII)-2NBATCH complex was 1:2 investigated from Job's method of continuous variation, Mole ratio method and slope ratio method. The interference of diverse ions was studied and masking agents were used wherever necessary. The present method was successfully applied for determination of osmium(VIII) from binary, ternary and synthetic mixtures corresponding to alloys and real samples. The validity of the method was confirmed by finding the relative standard deviation for five determinations which was 0.29%. PMID:27380306

  12. First Measurement of the Ratio sigma_(t-tbar) / sigma_(Z/\\gamma*->ll) and Precise Extraction of the t-tbar Cross Section

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2010-04-01

    We report a measurement of the ratio of the t{bar t} to Z/{gamma}* production cross sections in {radical}s = 1.96 TeV p{bar p} collisions using data corresponding to an integrated luminosity of up to 4.6 fb{sup -1}, collected by the CDF II detector. The t{bar t} cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/{gamma}* {yields} ll cross section predicted by the standard model, the extracted t{bar t} cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result {sigma}{sub t{bar t}} = 7.70 {+-} 0.52 pb, for a top-quark mass of 172.5 GeV/c{sup 2}.

  13. Waves and bumps in neuronal networks with axo-dendritic synaptic interactions

    NASA Astrophysics Data System (ADS)

    Coombes, S.; Lord, G. J.; Owen, M. R.

    2003-04-01

    We consider a firing rate model of a neuronal network continuum that incorporates axo-dendritic synaptic processing and the finite conduction velocities of action potentials. The model equation is an integral one defined on a spatially extended domain. Apart from a spatial integral mixing the network connectivity function with space-dependent delays, arising from non-instantaneous axonal communication, the integral model also includes a temporal integration over some appropriately identified distributed delay kernel. These distributed delay kernels are biologically motivated and represent the response of biological synapses to spiking inputs. They are interpreted as Green’s functions of some linear differential operator. Exploiting this Green’s function description we discuss formal reductions of this non-local system to equivalent partial differential equation (PDE) models. We distinguish between those spatial connectivity functions that give rise to local PDE models and those that give rise to PDE models with delayed non-local terms. For cases in which local PDEs are derived, we investigate traveling wave solutions in a comoving frame by numerically computing global heteroclinic connections for sigmoidal firing rate functions. We also calculate exact solutions, parameterized by axonal conduction velocity, for the Heaviside firing rate function (the sigmoidal firing rate function in the limit of infinite gain). The inclusion of synaptic adaptation is shown to alter traveling wave fronts to traveling pulses, which we study analytically and numerically in terms of a global homoclinic orbit. Finally, we consider the impact of dendritic interactions on waves and on static spatially localized solutions. Exact analysis for infinite gain shows that axonal delays do not affect the stability of single bumps. Furthermore, numerical continuation for finite gain leads to multiple bump solutions, and it is demonstrated that such localized multi-bumps are lost (in favor of

  14. Experiments to measure ablative Richtmyer-Meshkov growth of Gaussian bumps in plastic capsules

    SciTech Connect

    Loomis, Eric; Batha, Steve; Sedillo, Tom; Evans, Scott; Sorce, Chuck; Landen, Otto; Braun, Dave

    2010-06-02

    Growth of hydrodynamic instabilities at the interfaces of inertial confinement fusion capsules (ICF) due to ablator and fuel non-uniformities have been of primary concern to the ICF program since its inception. To achieve thermonuclear ignition at Megajoule class laser systems such as the NIF, targets must be designed for high implosion velocities, which requires higher in-flight aspect ratios (IFAR) and diminished shell stability. Controlling capsule perturbations is thus of the utmost importance. Recent simulations have shown that features on the outer surface of an ICF capsule as small as 10 microns wide and 100's of nanometers tall such as bumps, divots, or even dust particles can profoundly impact capsule performance by leading to material jetting or mix into the hotspot. Recent x-ray images of implosions on the NIF may be evidence of such mixing. Unfortunately, our ability to accurately predict these effects is uncertain due to disagreement between equation of state (EOS) models. In light of this, we have begun a campaign to measure the growth of isolated defects (Gaussian bumps) due to ablative Richtmyer-Meshkov in CH capsules to validate these models. The platform that has been developed uses halfraums with radiation temperatures near 75 eV (Rev. 4 foot-level) driven by 15-20 beams from the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY), which sends a ~2.5 Mbar shock into a planar CH foil. Gaussian-shaped bumps (20 microns wide, 4-7 microns tall) are deposited onto the ablation side of the target. On-axis radiography with a saran (Cl Heα - 2.8 keV) backlighter is used to measure bump evolution prior to shock breakout. Shock speed measurements will also be made with Omega's active shock breakout (ASBO) and streaked optical pyrometery (SOP) diagnostics in conjunction with filtered x-ray photodiode arrays (DANTE) to determine drive conditions in the target. These data will be used to discriminate between EOS models so

  15. Effects of PCB Pad Metal Finishes on the Cu-Pillar/Sn-Ag Micro Bump Joint Reliability of Chip-on-Board (COB) Assembly

    NASA Astrophysics Data System (ADS)

    Kim, Youngsoon; Lee, Seyong; Shin, Ji-won; Paik, Kyung-Wook

    2016-06-01

    While solder bumps have been used as the bump structure to form the interconnection during the last few decades, the continuing scaling down of devices has led to a change in the bump structure to Cu-pillar/Sn-Ag micro-bumps. Cu-pillar/Sn-Ag micro-bump interconnections differ from conventional solder bump interconnections in terms of their assembly processing and reliability. A thermo-compression bonding method with pre-applied b-stage non-conductive films has been adopted to form solder joints between Cu pillar/Sn-Ag micro bumps and printed circuit board vehicles, using various pad metal finishes. As a result, various interfacial inter-metallic compounds (IMCs) reactions and stress concentrations occur at the Cu pillar/Sn-Ag micro bumps joints. Therefore, it is necessary to investigate the influence of pad metal finishes on the structural reliability of fine pitch Cu pillar/Sn-Ag micro bumps flip chip packaging. In this study, four different pad surface finishes (Thin Ni ENEPIG, OSP, ENEPIG, ENIG) were evaluated in terms of their interconnection reliability by thermal cycle (T/C) test up to 2000 cycles at temperatures ranging from -55°C to 125°C and high-temperature storage test up to 1000 h at 150°C. The contact resistances of the Cu pillar/Sn-Ag micro bump showed significant differences after the T/C reliability test in the following order: thin Ni ENEPIG > OSP > ENEPIG where the thin Ni ENEPIG pad metal finish provided the best Cu pillar/Sn-Ag micro bump interconnection in terms of bump joint reliability. Various IMCs formed between the bump joint areas can account for the main failure mechanism.

  16. Effects of PCB Pad Metal Finishes on the Cu-Pillar/Sn-Ag Micro Bump Joint Reliability of Chip-on-Board (COB) Assembly

    NASA Astrophysics Data System (ADS)

    Kim, Youngsoon; Lee, Seyong; Shin, Ji-won; Paik, Kyung-Wook

    2016-03-01

    While solder bumps have been used as the bump structure to form the interconnection during the last few decades, the continuing scaling down of devices has led to a change in the bump structure to Cu-pillar/Sn-Ag micro-bumps. Cu-pillar/Sn-Ag micro-bump interconnections differ from conventional solder bump interconnections in terms of their assembly processing and reliability. A thermo-compression bonding method with pre-applied b-stage non-conductive films has been adopted to form solder joints between Cu pillar/Sn-Ag micro bumps and printed circuit board vehicles, using various pad metal finishes. As a result, various interfacial inter-metallic compounds (IMCs) reactions and stress concentrations occur at the Cu pillar/Sn-Ag micro bumps joints. Therefore, it is necessary to investigate the influence of pad metal finishes on the structural reliability of fine pitch Cu pillar/Sn-Ag micro bumps flip chip packaging. In this study, four different pad surface finishes (Thin Ni ENEPIG, OSP, ENEPIG, ENIG) were evaluated in terms of their interconnection reliability by thermal cycle (T/C) test up to 2000 cycles at temperatures ranging from -55°C to 125°C and high-temperature storage test up to 1000 h at 150°C. The contact resistances of the Cu pillar/Sn-Ag micro bump showed significant differences after the T/C reliability test in the following order: thin Ni ENEPIG > OSP > ENEPIG where the thin Ni ENEPIG pad metal finish provided the best Cu pillar/Sn-Ag micro bump interconnection in terms of bump joint reliability. Various IMCs formed between the bump joint areas can account for the main failure mechanism.

  17. Asteroseismic Analysis of the Internal Structure and Evolution of Red Giant Branch Bump Stars

    NASA Astrophysics Data System (ADS)

    Gai, Ning; Tang, Yanke

    2015-05-01

    The “bump” is a prominent feature of the red giant branch (RGB) luminosity function of stellar clusters. Through constructing a grid of models with different masses and metallicities to study the feature of the RGB bump luminosity we find that the luminosity increases almost monotonically with increasing mass for a given metallicity and decreases monotonically with increasing metallicity. Moreover, different stars have different shapes of the RGB bump. It is correlated with the sharpness of the H discontinuity, which is left over by the convection envelope during the first dredge-up. Using the periodicity in the small separations d01, d10 to probe the internal structure, we find that, at about half the acoustic radius, the sound speed has a sharp variation that is caused by a local depression of the first adiabatic exponent {{{Γ }}1} in the second helium ionization zone. It induces an oscillation modulation in d01, d10 with a period of 6.4 μ Hz. Meanwhile, in the same model, the base of the convective envelope is located at a relatively small acoustic radius {{t}envp}/T, which is about 10-1. It is too deep to detect the exact location of the bottom of the outer convective envelope. In order to discriminate the evolutionary status of different stars, we calculate the asymptotic g-mode period spacing {Δ }{{{\\Pi }}1}. We find that {Δ }{{{\\Pi }}1} decreases monotonically with evolution. It is a reliable parameter for distinguishing stars in different positions of the RGB bump.

  18. HUBBLE SPACE TELESCOPE MORPHOLOGIES OF z {approx} 2 DUST-OBSCURED GALAXIES. II. BUMP SOURCES

    SciTech Connect

    Bussmann, R. S.; Dey, Arjun; Lotz, J.; Jannuzi, B. T.; Armus, L.; Desai, V.; Soifer, B. T.; Brown, M. J. I.; Eisenhardt, P.; Higdon, J.; Higdon, S.; Le Floc'h, E.; Melbourne, J.; Weedman, D.

    2011-05-20

    We present Hubble Space Telescope imaging of 22 ultra-luminous infrared galaxies (ULIRGs) at z {approx} 2 with extremely red R - [24] colors (called dust-obscured galaxies, or DOGs) which have a local maximum in their spectral energy distribution (SED) at rest-frame 1.6 {mu}m associated with stellar emission. These sources, which we call 'bump DOGs', have star formation rates (SFRs) of 400-4000 M{sub sun} yr{sup -1} and have redshifts derived from mid-IR spectra which show strong polycyclic aromatic hydrocarbon emission-a sign of vigorous ongoing star formation. Using a uniform morphological analysis, we look for quantifiable differences between bump DOGs, power-law DOGs (Spitzer-selected ULIRGs with mid-IR SEDs dominated by a power law and spectral features that are more typical of obscured active galactic nuclei than starbursts), submillimeter-selected galaxies, and other less-reddened ULIRGs from the Spitzer Extragalactic First Look Survey. Bump DOGs are larger than power-law DOGs (median Petrosian radius of 8.4 {+-} 2.7 kpc versus 5.5 {+-} 2.3 kpc) and exhibit more diffuse and irregular morphologies (median M{sub 20} of -1.08 {+-} 0.05 versus -1.48 {+-} 0.05). These trends are qualitatively consistent with expectations from simulations of major mergers in which merging systems during the peak SFR period evolve from M{sub 20} = -1.0 to M{sub 20} = -1.7. Less-obscured ULIRGs (i.e., non-DOGs) tend to have more regular, centrally peaked, single-object morphologies rather than diffuse and irregular morphologies. This distinction in morphologies may imply that less-obscured ULIRGs sample the merger near the end of the peak SFR period. Alternatively, it may indicate that the intense star formation in these less-obscured ULIRGs is not the result of a recent major merger.

  19. Enigmatic Extinction: An Investigation of the 2175Å Extinction Bump in M101

    NASA Astrophysics Data System (ADS)

    Danowski, Meredith E.; Cook, Timothy; Gordon, Karl D.; Chakrabarti, Supriya; Lawton, Brandon L.; Misselt, Karl A.

    2014-06-01

    Evidence from studies of starburst galaxies indicates that active formation of high mass stars modifies the UV dust extinction curve as seen by a lack of the characteristic 2175Å bump. For over 45 years, the source of the 2175Å extinction feature has yet to be positively identified. Small aromatic/PAH grains are suggested as a leading contender in dust grain models. The face-on spiral galaxy M101 is an ideal laboratory for the study of dust, with many well-studied HII regions and a steep metallicity and ionization gradient.The Interstellar Medium Absorption Gradient Experiment Rocket (IMAGER) probes the correlation between dust extinction, and the metallicity and radiation environment in M101 at ultraviolet wavelengths. IMAGER simultaneously images M101 in three 400Å-wide bandpasses, measuring the apparent strength of the 2175Å bump and the UV continuum.Combining data from IMAGER with high S/N far- and near- UV observations from the MAMA detectors on the Hubble STIS instrument, we examine the apparent strength of the 2175Å bump in HII regions of M101. With additional infrared data from Spitzer, the DIRTY radiative transfer model, and stellar evolution models, we probe the correlation between the 2175Å feature and the aromatic/PAH features across HII regions of varying metallicity and radiation field hardness. The results of this experiment will directly impact our understanding of the nature of dust and our ability to accurately account for the effects of dust on observations at all redshifts.

  20. On the ΔV bump HB Parameter in Globular Clusters

    NASA Astrophysics Data System (ADS)

    Di Cecco, A.; Bono, G.; Stetson, P. B.; Pietrinferni, A.; Becucci, R.; Cassisi, S.; Degl'Innocenti, S.; Iannicola, G.; Prada Moroni, P. G.; Buonanno, R.; Calamida, A.; Caputo, F.; Castellani, M.; Corsi, C. E.; Ferraro, I.; Dall'Ora, M.; Monelli, M.; Nonino, M.; Piersimoni, A. M.; Pulone, L.; Romaniello, M.; Salaris, M.; Walker, A. R.; Zoccali, M.

    2010-03-01

    We present new empirical estimates of the ΔV bump HB parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data. Together with similar evaluations available in the literature, we ended up with a sample of 62 GGCs covering a very broad range in metal content (-2.16 dex <= [M/H] <= -0.58 dex). Adopting the homogeneous metallicity scale provided either by Kraft & Ivans or by Carretta et al., we found that the observed ΔV bump HB parameters are larger than predicted. In the metal-poor regime ([M/H] <~ -1.7, -1.6 dex) 40% of GCs show discrepancies of 2σ (≈0.40 mag) or more. Evolutionary models that account either for α- and CNO-enhancement or for helium enhancement do not alleviate the discrepancy between theory and observations. The outcome is the same if we use the new solar heavy-element mixture. The comparison between α- and CNO-enhanced evolutionary models and observations in the Carretta et al. metallicity scale also indicates that observed ΔV bump HB parameters, in the metal-rich regime ([M/H] >= 0), might be systematically smaller than predicted. Based in part on data obtained from the ESO/ST-ECF Science Archive Facility, from the Isaac Newton Group Archive which is maintained as part of the CASU Astronomical Data Centre at the Institute of Astronomy, Cambridge, and from the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency.

  1. Eyelid bump

    MedlinePlus

    ... cause trouble with your vision. If you have blepharitis (see eye redness ), you are more likely to ... you are prone to getting styes or have blepharitis, it may help to carefully clean off excess ...

  2. An RDL UBM Structural Design for Solving Ultralow- K Delamination Problem of Cu Pillar Bump Flip Chip BGA Packaging

    NASA Astrophysics Data System (ADS)

    Chen, K. M.; Wu, C. Y.; Wang, C. H.; Cheng, H. C.; Huang, N. C.

    2014-11-01

    Copper (Cu) pillar bumps tend to induce high thermal-mechanical stress during environmental tests and fabrication processes due to the high hardness of Cu, especially when applied with an ultralow- K (ULK) chip. A previous experiment showed that interfacial delamination was often observed in the ULK layers of conventional Cu pillar bump-type flip chip ball grid array (FCBGA) packages under thermal cycling, where under bump metallurgy (UBM) layers directly sit on the metal pads of silicon chips (herein termed ``direct UBM structure''). In this study, a UBM pad relocation scheme through redistribution layer (RDL) technology (herein termed ``RDL UBM structure'') is proposed to relieve the stress or ULK delamination issue. The proposed technique is tested on Cu pillar bump-type FCBGA packages subjected to thermal loading, the effectiveness of which is demonstrated through finite element stress simulation and experimental reliability tests. Simulation results reveal that the RDL UBM structure can greatly reduce the maximum stress in the ULK layers by as much as about 10% to 44%. Besides, it turns out that the Cu pillar bump-type FCBGA packages with the RDL UBM structure show good interconnect reliability performance in terms of thermal cycling, highly accelerated stress, and high-temperature storage.

  3. Characterization of Multi-Domain Bumps of Organic Resists in Color Filters for Wide-Viewing-Angle Liquid Crystal Displays

    NASA Astrophysics Data System (ADS)

    Koo, Horng-Show; Chen, Mi; Yang, Sheng-Hung; Kawai, Tomoji

    2008-06-01

    Negative-type multi-domain vertical alignment (MVA) photoresists have technically been fabricated and integrated in color filter processing for the application of wide-viewing-angle liquid crystal displays. The expectable results including excellent light transmittance, stability and uniformity of protrudent bumps in shape, superior reliability in material characteristics and wider gamut have extensively been achieved. The superior brightness (GY) of negative-type photo resists used in color filters to positive-type photoresists is attended with the result of excellent transmittances. The transmittances of positive-type and negative-type protrudent bumps photoresists in color filters are 70 and 100%, respectively. NTSC ratio of the color-filter sample with negative-type photoresist in MVA protrudent bumps is improved from 61.9 to 62.8% and higher. Comparisons in characteristics between negative-type (NPR) photoresist and positive-type (PPR) photoresist materials have eventually been analyzed and demonstrated as well.

  4. High resolution 3D imaging of bump-bonds by means of synchrotron radiation computed laminography

    NASA Astrophysics Data System (ADS)

    Cecilia, A.; Hamann, E.; Koenig, T.; Xu, F.; Cheng, Y.; Helfen, L.; Ruat, M.; Scheel, M.; Zuber, M.; Baumbach, T.; Fauler, A.; Fiederle, M.

    2013-12-01

    During the flip-chip bonding process of a semiconductor sensor onto readout electronics, a formation of defects may take place, like solder joint displacements, voids, cracks, pores and bridges. This may result in blind spots on the detector, which are insensitive to photons and thus reduce the detector performance. In this work, the flip-chip interconnections of selected CdTe and GaAs Medipix detectors were investigated by synchrotron radiation computed laminography at a micrometer scale. The analysis of the volume rendering proved the presence of voids in the CdTe sensor flip-chip interconnections, with sizes between 3 μm and 9 μm. These voids can be harmful for the long term use of the device, because their presence weakens the adhesive strength between a contact and the readout electronics. Consequently, their formation needs to be avoided. The GaAs Medipix detectors investigated include two sensors that were produced with different flip-chip methods. The comparison of the 3D renderings of the bump-bond interconnections in the two GaAs sensors demonstrated the presence of a misalignment in the range of 5-12 μm between pixel passivation and bump-bonds in the detector produced with an older technique. In contrast to this, no misalignment was observed for the most recently produced detector. The only remarkable observation is the presence of ``satellites'' of solder that do not compromise the detector operation.

  5. Initial test results of the Los Alamos proton-storage-ring bump-magnet system

    SciTech Connect

    Rose, C.R.; Barlow, D.B.; Redd, D.B.

    1997-09-01

    An upgrade program for increasing the stored beam current in the LANSCE Proton Storage is presently under way. Part of the upgrade effort has been to design, specify, and add four bump-magnet/modulator systems to the ring. This paper describes the initial test results of the first bump-magnet/modulator system. The paper begins with an overview of the pulsed-power system including important specifications of the modulator, magnet, cabling, and control system. In the main portion of the paper, waveforms and test data are included showing the accuracy, repeatability, and stability of the magnet-current pulses. These magnet pulses are programmable both in rise and fall time as well as in amplitude. The amplitude can be set between 50 and 300 A, the rise-time is fixed at 1 ms, and the linear fall-time can be varied between 500 {mu}s and 1500 {mu}s. Other issues such as loading effects and power dissipation in the magnet-bore beamtube are examined and reported.

  6. Miniaturization of Micro-Solder Bumps and Effect of IMC on Stress Distribution

    NASA Astrophysics Data System (ADS)

    Choudhury, Soud Farhan; Ladani, Leila

    2016-04-01

    As the joints become smaller in more advanced packages and devices, intermetallic (IMCs) volume ratio increases, which significantly impacts the overall mechanical behavior of joints. The existence of only a few grains of Sn (Tin) and IMC materials results in anisotropic elastic and plastic behavior which is not detectable using conventional finite element (FE) simulation with average properties for polycrystalline material. In this study, crystal plasticity finite element (CPFE) simulation is used to model the whole joint including copper, Sn solder and Cu6Sn5 IMC material. Experimental lap-shear test results for solder joints from the literature were used to validate the models. A comparative analysis between traditional FE, CPFE and experiments was conducted. The CPFE model was able to correlate the experiments more closely compared to traditional FE analysis because of its ability to capture micro-mechanical anisotropic behavior. Further analysis was conducted to evaluate the effect of IMC thickness on stress distribution in micro-bumps using a systematic numerical experiment with IMC thickness ranging from 0% to 80%. The analysis was conducted on micro-bumps with single crystal Sn and bicrystal Sn. The overall stress distribution and shear deformation changes as the IMC thickness increases. The model with higher IMC thickness shows a stiffer shear response, and provides a higher shear yield strength.

  7. The effects of phase decorrelation on the dynamics of the bump-on-tail instability

    SciTech Connect

    Tholerus, E. Hellsten, T.; Johnson, T.

    2015-08-15

    The dynamics of the bump-on-tail instability has been studied. The novelty of the work is the analysis of how the bump-on-tail dynamics is affected by an extrinsic stochastisation of the phase of the wave-particle interaction; here referred to as phase decorrelation. For this purpose, a nonlinear Monte Carlo model has been developed. When the characteristic time scale for macroscopic phase decorrelation becomes shorter than time scales of nonlinear wave-particle dynamics, the system may be described quasilinearly, with the phase decorrelation being replaced by a quasilinear diffusion coefficient in particle energy. A purely quasilinear Monte Carlo model, which is typically less computationally demanding than the fully nonlinear description due to the reduced dimensionality of phase space, has been developed for comparison. In this paper, parameter regimes, where the nonlinear and the quasilinear descriptions quantitatively agree on a macroscopic level, have been investigated, using combined theoretical and numerical analyses. Qualitative effects on the macroscopic dynamics by the presence of phase decorrelation and/or by structures of the energy distribution function in the proximity of the wave-particle resonance are also studied.

  8. R package PRIMsrc: Bump Hunting by Patient Rule Induction Method for Survival, Regression and Classification

    PubMed Central

    Dazard, Jean-Eudes; Choe, Michael; LeBlanc, Michael; Rao, J. Sunil

    2015-01-01

    PRIMsrc is a novel implementation of a non-parametric bump hunting procedure, based on the Patient Rule Induction Method (PRIM), offering a unified treatment of outcome variables, including censored time-to-event (Survival), continuous (Regression) and discrete (Classification) responses. To fit the model, it uses a recursive peeling procedure with specific peeling criteria and stopping rules depending on the response. To validate the model, it provides an objective function based on prediction-error or other specific statistic, as well as two alternative cross-validation techniques, adapted to the task of decision-rule making and estimation in the three types of settings. PRIMsrc comes as an open source R package, including at this point: (i) a main function for fitting a Survival Bump Hunting model with various options allowing cross-validated model selection to control model size (#covariates) and model complexity (#peeling steps) and generation of cross-validated end-point estimates; (ii) parallel computing; (iii) various S3-generic and specific plotting functions for data visualization, diagnostic, prediction, summary and display of results. It is available on CRAN and GitHub. PMID:26798326

  9. Miniaturization of Micro-Solder Bumps and Effect of IMC on Stress Distribution

    NASA Astrophysics Data System (ADS)

    Choudhury, Soud Farhan; Ladani, Leila

    2016-07-01

    As the joints become smaller in more advanced packages and devices, intermetallic (IMCs) volume ratio increases, which significantly impacts the overall mechanical behavior of joints. The existence of only a few grains of Sn (Tin) and IMC materials results in anisotropic elastic and plastic behavior which is not detectable using conventional finite element (FE) simulation with average properties for polycrystalline material. In this study, crystal plasticity finite element (CPFE) simulation is used to model the whole joint including copper, Sn solder and Cu6Sn5 IMC material. Experimental lap-shear test results for solder joints from the literature were used to validate the models. A comparative analysis between traditional FE, CPFE and experiments was conducted. The CPFE model was able to correlate the experiments more closely compared to traditional FE analysis because of its ability to capture micro-mechanical anisotropic behavior. Further analysis was conducted to evaluate the effect of IMC thickness on stress distribution in micro-bumps using a systematic numerical experiment with IMC thickness ranging from 0% to 80%. The analysis was conducted on micro-bumps with single crystal Sn and bicrystal Sn. The overall stress distribution and shear deformation changes as the IMC thickness increases. The model with higher IMC thickness shows a stiffer shear response, and provides a higher shear yield strength.

  10. Type II spectral bumps and Diagnostics on the Properties of the Radio Source

    NASA Astrophysics Data System (ADS)

    Feng, S.; CHEN, Y.; Kong, X.; Li, G.; Song, H.; Feng, X.; Liu, Y.; Guo, F.

    2012-12-01

    It is now widely accepted that type II radio bursts are due to energetic electrons accelerated at coronal shocks. Radio observations, however, have poor or no spatial resolution to pinpoint the exact acceleration locations of these electrons. In this presentation we propose a novel method to infer the source properties of type II radio bursts by combining radio and white light observations. The key assumption is to relate specific morphological features (e.g., spectral bumps) of the dynamic spectra of type II radio bursts to imaging features (e.g., CME and its driven shock entering into a streamer) along the CME propagation. To verify the above proposal, we investigate two type IIs with spectral bump features and examine their association with CME-streamer interactions. The features are interpreted as a natural result of the shock-radio-emitting region entering the dense streamer structure. It is inferred that the type II radio bursts are excited at the flanks of the CME-driven shock (where the large scale shock geometry is of quasi-perpendicular), and the radio emission is spatially confined to a very localized region.

  11. Biomimetic Water-Collecting Fabric with Light-Induced Superhydrophilic Bumps.

    PubMed

    Wang, Yuanfeng; Wang, Xiaowen; Lai, Chuilin; Hu, Huawen; Kong, Yeeyee; Fei, Bin; Xin, John H

    2016-02-10

    To develop an efficient water-collecting surface that integrates both fast water-capturing and easy drainage properties is of high current interest for addressing global water issues. In this work, a superhydrophobic surface was fabricated on cotton fabric via manipulation of both the surface roughness and surface energy. This was followed by a subsequent spray coating of TiO2 nanosol that created light-induced superhydrophilic bumps with a unique raised structure as a result of the interfacial tension of the TiO2 nanosol sprayed on the superhydrophobic fiber surface. These raised TiO2 bumps induce both a wettability gradient and a shape gradient, synergistically accelerating water coalescence and water collection. The in-depth study revealed that the quantity and the distribution of the TiO2 had a significant impact on the final water collection efficiency. This inexpensive and facilely fabricated fabric biomimicks the desert beetle's back and spider silk, which are capable of fog harvesting without additional energy consumption. PMID:26652924

  12. Direct Reading Particle Counters: Calibration Verification and Multiple Instrument Agreement via Bump Testing

    SciTech Connect

    Jankovic, John; Zontek, Tracy L.; Ogle, Burton R.; Hollenbeck, Scott

    2015-01-27

    We examined the calibration records of two direct reading instruments designated as condensation particle counters in order to determine the number of times they were found to be out of tolerance at annual manufacturer's recalibration. For both instruments were found to be out of tolerance more times than within tolerance. And, it was concluded that annual calibration alone was insufficient to provide operational confidence in an instrument's response. Thus, a method based on subsequent agreement with data gathered from a newly calibrated instrument was developed to confirm operational readiness between annual calibrations, hereafter referred to as bump testing. The method consists of measuring source particles produced by a gas grille spark igniter in a gallon-size jar. Sampling from this chamber with a newly calibrated instrument to determine the calibrated response over the particle concentration range of interest serves as a reference. Agreement between this reference response and subsequent responses at later dates implies that the instrument is performing as it was at the time of calibration. Side-by-side sampling allows the level of agreement between two or more instruments to be determined. This is useful when simultaneously collected data are compared for differences, i.e., background with process aerosol concentrations. A reference set of data was obtained using the spark igniter. The generation system was found to be reproducible and suitable to form the basis of calibration verification. Finally, the bump test is simple enough to be performed periodically throughout the calibration year or prior to field monitoring.

  13. A New Copper Alloy Film for Barrierless Si Metallization and Solder Bump Flip-Chip Application

    NASA Astrophysics Data System (ADS)

    Lin, Chon-Hsin

    2013-05-01

    In this study, a copper alloy, Cu(MnNx), film is developed by cosputtering Cu and Mn on a barrierless Si substrate within an Ar/N2 gas atmosphere. The resulting alloy film exhibits good thermal stability and adhesion to the substrate with no noticeable interactions between the film and the substrate after annealing at 700 °C for 1 h, indicating that the film is thermally stable. The alloy film shall be able to replace both the wetting and diffusion layers for the flip-chip solder joints in conventional under bump metallurgy to reduce the manufacturing cost. We also observe that the Cu(MnNx) alloy exhibits a solder ability comparable to that of pure Cu and a dissolution rate lower than that of pure Cu by at least one order of magnitude. The alloy's consumption rate is comparable to that of Ni, rendering the alloy a candidate material in both barrierless Si metallization and solder bump flip-chip application.

  14. Indium-bump-free antimonide superlattice membrane detectors on a silicon substrates

    NASA Astrophysics Data System (ADS)

    Zamiri, M.; Klein, B.; Schuler, T.; Myers, S.; Cavallo, F.; Krishna, S.

    2016-05-01

    We present an approach to realize antimonide based superlattices on silicon substrates without using conventional Indium-bump hybridization. In this approach, PIN based superlattice detectors are grown on top of a 60 nm Al0.6Ga0.4Sb sacrificial layer on a GaSb host substrate. Following the growth, the individual pixels are transferred using our epitaxiallift off technique, which consists of a wet-etch to undercut the pixels followed by a dry-stamp process to transfer the pixels to a silicon substrate prepared with a gold layer. Structural and optical characterization of the transferred pixels was done using an optical microscope, scanning electron microscopy and photoluminescence. The interface between the transferred pixels and the new substrate was abrupt and no significant degradation in the optical quality was observed. An Indium-bump-free membrane detector was then fabricated using this approach. Spectral response measurements provided a 100% cut-off wavelength of 4.3 μm at 77 K. The performance of the membrane detector was compared to a control detector on the as-grown substrate. The membrane detector was limited by surface leakage current. The proposed approach could pave the way for wafer-level integration of photonic detectors on silicon substrates, which could dramatically reduce the cost of these detectors.

  15. Indium-bump-free antimonide superlattice membrane detectors on silicon substrates

    NASA Astrophysics Data System (ADS)

    Zamiri, M.; Klein, B.; Schuler-Sandy, T.; Myers, S.; Dahiya, V.; Cavallo, F.; Krishna, S.

    2016-02-01

    We present an approach to realize antimonide superlattices on silicon substrates without using conventional Indium-bump hybridization. In this approach, PIN superlattices are grown on top of a 60 nm Al0.6Ga0.4Sb sacrificial layer on a GaSb host substrate. Following the growth, the individual pixels are transferred using our epitaxial-lift off technique, which consists of a wet-etch to undercut the pixels followed by a dry-stamp process to transfer the pixels to a silicon substrate prepared with a gold layer. Structural and optical characterization of the transferred pixels was done using an optical microscope, scanning electron microscopy, and photoluminescence. The interface between the transferred pixels and the new substrate was abrupt, and no significant degradation in the optical quality was observed. An Indium-bump-free membrane detector was then fabricated using this approach. Spectral response measurements provided a 100% cut-off wavelength of 4.3 μm at 77 K. The performance of the membrane detector was compared to a control detector on the as-grown substrate. The membrane detector was limited by surface leakage current. The proposed approach could pave the way for wafer-level integration of photonic detectors on silicon substrates, which could dramatically reduce the cost of these detectors.

  16. Comparative case study of yielding and critical coal pillar designs in bump-prone strata

    SciTech Connect

    Koehler, J.R.; DeMarco, M.J.

    1995-11-01

    The failure of yield pillar-based gate road designs to provide adequate ground control performance is primarily related to the use of ``critically`` sized chain pillars. A ``critical`` pillar is one that falls into a range of pillar sizes that are too large to either yield nonviolently or yield before the roof and floor sustain permanent damage, but are to small to support full longwall abutment loads. To directly compare the in-mine performance of critical and yielding pillar designs, the US Bureau of Mines recently completed a field study in a tapering gate road at the Sunnyside No. 1 Mine, Sunnyside, UT. Extreme pillar stresses and associated coal bumps characterize the response to first panel mining of a 16.8-m-wide critical design. Significantly lower pillar stresses, early yielding of the pillar and adjacent panel rib, and an absence of coal bumps suggest that a narrower 12.2-m-wide design more closely approaches proper yield pillar dimensions. Probehole drilling of several 10.6-m-wide pillars revealed low stress levels and substantial pillar and panel rib yielding prior to abutment onset, suggesting a properly functioning yield pillar design.

  17. 3D integration technology for sensor application using less than 5μm-pitch gold cone-bump connpdfection

    NASA Astrophysics Data System (ADS)

    Motoyoshi, M.; Miyoshi, T.; Ikebec, M.; Arai, Y.

    2015-03-01

    Three-dimensional (3D) integrated circuit (IC) technology is an effective solution to reduce the manufacturing costs of advanced two-dimensional (2D) large-scale integration (LSI) while ensuring equivalent device performance and functionalities. This technology allows a new device architecture using stacked detector/sensor devices with a small dead sensor area and high-speed operation that facilitates hyper-parallel data processing. In pixel detectors or focal-plane sensor devices, each pixel area must accommodate many transistors without increasing the pixel size. Consequently, many methods to realize 3D-LSI devices have been developed to meet this requirement by focusing on the unit processes of 3D-IC technology, such as through-silicon via formation and electrical and mechanical bonding between tiers of the stack. The bonding process consists of several unit processes such as bump or metal contact formation, chip/wafer alignment, chip/wafer bonding, and underfill formation; many process combinations have been reported. Our research focuses on a versatile bonding technology for silicon LSI, compound semiconductor, and microelectromechanical system devices at temperatures of less than 200oC for heterogeneous integration. A gold (Au) cone bump formed by nanoparticle deposition is one of the promising candidates for this purpose. This paper presents the experimental result of a fabricated prototype with 3-μm-diameter Au cone-bump connections with adhesive injection, and compares it with that of an indium microbump (μ-bump). The resistance of the 3-μm-diameter Au cone bump is approximately 6 Ω. We also investigated the influence of stress caused by the bump junction on the MOS characteristics.

  18. Precision powder feeder

    DOEpatents

    Schlienger, M. Eric; Schmale, David T.; Oliver, Michael S.

    2001-07-10

    A new class of precision powder feeders is disclosed. These feeders provide a precision flow of a wide range of powdered materials, while remaining robust against jamming or damage. These feeders can be precisely controlled by feedback mechanisms.

  19. Ultra-fast Movies Resolve Ultra-short Pulse Laser Ablation and Bump Formation on Thin Molybdenum Films

    NASA Astrophysics Data System (ADS)

    Domke, Matthias; Rapp, Stephan; Huber, Heinz

    For the monolithic serial interconnection of CIS thin film solar cells, 470 nm molybdenum films on glass substrates must be separated galvanically. The single pulse ablation with a 660 fs laser at a wavelength of 1053 nm is investigated in a fluence regime from 0.5 to 5.0 J/cm2. At fluences above 2.0 J/cm2 bump and jet formation can be observed that could be used for creating microstructures. For the investigation of the underlying mechanisms of the laser ablation process itself as well as of the bump or jet formation, pump probe microscopy is utilized to resolve the transient ablation behavior.

  20. Recent versus Remote: Flashbulb Memory for 9/11 and Self-Selected Events from the Reminiscence Bump

    ERIC Educational Resources Information Center

    Denver, Jenny Y.; Lane, Sean M.; Cherry, Katie E.

    2010-01-01

    In two related studies, we examined flashbulb memories acquired from different points in the lifespan in younger and older adults. When asked to remember flashbulb memories from their lives, older adults were most likely to recall events from the reminiscence bump (Study 1A). In Study 1B, younger and older adults recalled 9/11 and a personal…

  1. Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron

    NASA Astrophysics Data System (ADS)

    Zou, Ye; Tang, Jingyu; Yang, Zheng; Jing, Hantao

    2014-02-01

    This paper proposes a novel method to extract extremely weak beam from a high-intensity proton rapid cycling synchrotron (RCS) in the parasitic mode, while maintaining the normal fast extraction. The usual slow extraction method from a synchrotron by employing third-order resonance cannot be applied in a high-intensity RCS due to a very short flat-top at the extraction energy and the strict control on beam loss. The proposed parasitic slow extraction method moves the beam to scrape a scattering foil prior to the fast beam extraction by employing either a local orbit bump or momentum deviation or their combination, so that the halo part of the beam will be scattered. A part of the scattered particles will be extracted from the RCS and guided to the experimental area. The slow extraction process can last about a few milliseconds before the beam is extracted by the fast extraction system. The method has been applied to the RCS of China Spallation Neutron Source. With 1.6 GeV in the extraction energy, 62.5 μA in the average current and 25 Hz in the repetition rate for the RCS, the proton intensity by the slow extraction method can be up to 2×104 protons per cycle or 5×105 protons per second. The extracted beam has also a good time structure of approximately uniform in a spill which is required for many applications such as detector tests. Detailed studies including the scattering effect in the foil, the local orbit bump by the bump magnets and dispersive orbit bump by modifying the RF pattern, the multi-particle simulations by ORBIT and TURTLE codes, and some technical features for the extraction magnets are presented.

  2. Solderjet bumping technique used to manufacture a compact and robust green solid-state laser

    NASA Astrophysics Data System (ADS)

    Ribes, P.; Burkhardt, T.; Hornaff, M.; Kousar, S.; Burkhardt, D.; Beckert, E.; Gilaberte, M.; Guilhot, D.; Montes, D.; Galan, M.; Ferrando, S.; Laudisio, M.; Belenguer, T.; Ibarmia, S.; Gallego, P.; Rodríguez, J. A.; Eberhardt, R.; Tünnermann, A.

    2015-06-01

    Solder-joining using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glasses, ceramics and optical crystals due to a localized and minimized input of thermal energy. The Solderjet Bumping technique is used to assemble a miniaturized laser resonator in order to obtain higher robustness, wider thermal conductivity performance, higher vacuum and radiation compatibility, and better heat and long term stability compared with identical glued devices. The resulting assembled compact and robust green diode-pumped solid-state laser is part of the future Raman Laser Spectrometer designed for the Exomars European Space Agency (ESA) space mission 2018.

  3. Electronic scattering of pseudo-magnetic field induced by local bump in graphene

    NASA Astrophysics Data System (ADS)

    Yang, Mou; Cui, Yan; Wang, Rui-Qiang; Zhao, Hong-Bo

    2012-10-01

    We investigated the electronic scattering properties of a local bump strain in graphene sheet in frame of Born approximation. The differential scattering cross section is a function of outgoing and incident angles and has the six-fold rotational symmetry with respect to both angles. The incident plane wave is scattered into two backward fan-waves in different directions in low energy limit and is split into two branches spanning the angle reversely proportional to the incident wavevector k in high energy limit. The total scattering cross section depends on incident wavevector by the form k5 in the former limit, while it is independent of k and sensitive to the incident orientation in the latter limit. We explained these features using the symmetry of the strain-induced pseudo-magnetic field.

  4. Nonuniqueness and multi-bump solutions in parabolic problems with the p-Laplacian

    NASA Astrophysics Data System (ADS)

    Benedikt, Jiří; Girg, Petr; Kotrla, Lukáš; Takáč, Peter

    2016-01-01

    The validity of the weak and strong comparison principles for degenerate parabolic partial differential equations with the p-Laplace operator Δp is investigated for p > 2. This problem is reduced to the comparison of the trivial solution (≡0, by hypothesis) with a nontrivial nonnegative solution u (x, t). The problem is closely related also to the question of uniqueness of a nonnegative solution via the weak comparison principle. In this article, realistic counterexamples to the uniqueness of a nonnegative solution, the weak comparison principle, and the strong maximum principle are constructed with a nonsmooth reaction function that satisfies neither a Lipschitz nor an Osgood standard "uniqueness" condition. Nonnegative multi-bump solutions with spatially disconnected compact supports and zero initial data are constructed between sub- and supersolutions that have supports of the same type.

  5. Low-loss ultra-subwavelength hybrid plasmonic waveguide based on metallic bump structures

    NASA Astrophysics Data System (ADS)

    Olyaeefar, Babak; Khoshsima, Habib

    2014-03-01

    Sharp metal edges (like wedge or triangular geometries) have been widely studied as low-loss surface plasmon polariton (SPP) waveguiding structures. However, fabrication difficulties lead to round-shaped tips which have larger mode size and shorter propagation length. As a solution, here we present an easy to realize structure for turning an edge-less bump metallic geometry (whose fabrication is less troublesome) into a hybrid one. Through investigating the geometrical dispersion, propagation lengths of up to half a millimetre and effective mode areas as small as λ2/330 are obtained for the 1.55 µm telecommunication wavelength. Gain-assisted SPP propagation is also considered by introducing gain in the InGaAsP material, for which critical gain as low as 11 cm-1 is calculated. Finally, obtained results suggest that the designed waveguide can find various applications in nanoscale waveguiding.

  6. Iron Opacity Bump Changes the Stability and Structure of Accretion Disks in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Jiang, Yan-Fei; Davis, Shane W.; Stone, James M.

    2016-08-01

    Accretion disks around supermassive black holes have regions where the Rosseland mean opacity can be larger than the electron scattering opacity due to the large number of bound–bound transitions in iron. We study the effects of this iron opacity “bump” on the thermal stability and vertical structure of radiation-pressure-dominated accretion disks, utilizing three-dimensional radiation magnetohydrodynamic (MHD) simulations in the local shearing box approximation. The simulations self-consistently calculate the heating due to MHD turbulence caused by magneto-rotational instability and radiative cooling by using the radiative transfer module based on a variable Eddington tensor in Athena. For a 5 × 108 solar mass black hole with ˜3% of the Eddington luminosity, a model including the iron opacity bump maintains its structure for more than 10 thermal times without showing significant signs of thermal runaway. In contrast, if only electron scattering and free–free opacity are included as in the standard thin disk model, the disk collapses on the thermal timescale. The difference is caused by a combination of (1) an anti-correlation between the total optical depth and the midplane pressure, and (2) enhanced vertical advective energy transport. These results suggest that the iron opacity bump may have a strong impact on the stability and structure of active galactic nucleus (AGN) accretion disks, and may contribute to a dependence of AGN properties on metallicity. Since this opacity is relevant primarily in UV emitting regions of the flow, it may help to explain discrepancies between observation and theory that are unique to AGNs.

  7. Direct Reading Particle Counters: Calibration Verification and Multiple Instrument Agreement via Bump Testing

    DOE PAGESBeta

    Jankovic, John; Zontek, Tracy L.; Ogle, Burton R.; Hollenbeck, Scott

    2015-01-27

    We examined the calibration records of two direct reading instruments designated as condensation particle counters in order to determine the number of times they were found to be out of tolerance at annual manufacturer's recalibration. For both instruments were found to be out of tolerance more times than within tolerance. And, it was concluded that annual calibration alone was insufficient to provide operational confidence in an instrument's response. Thus, a method based on subsequent agreement with data gathered from a newly calibrated instrument was developed to confirm operational readiness between annual calibrations, hereafter referred to as bump testing. The methodmore » consists of measuring source particles produced by a gas grille spark igniter in a gallon-size jar. Sampling from this chamber with a newly calibrated instrument to determine the calibrated response over the particle concentration range of interest serves as a reference. Agreement between this reference response and subsequent responses at later dates implies that the instrument is performing as it was at the time of calibration. Side-by-side sampling allows the level of agreement between two or more instruments to be determined. This is useful when simultaneously collected data are compared for differences, i.e., background with process aerosol concentrations. A reference set of data was obtained using the spark igniter. The generation system was found to be reproducible and suitable to form the basis of calibration verification. Finally, the bump test is simple enough to be performed periodically throughout the calibration year or prior to field monitoring.« less

  8. Iron Opacity Bump Changes the Stability and Structure of Accretion Disks in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Jiang, Yan-Fei; Davis, Shane W.; Stone, James M.

    2016-08-01

    Accretion disks around supermassive black holes have regions where the Rosseland mean opacity can be larger than the electron scattering opacity due to the large number of bound–bound transitions in iron. We study the effects of this iron opacity “bump” on the thermal stability and vertical structure of radiation-pressure-dominated accretion disks, utilizing three-dimensional radiation magnetohydrodynamic (MHD) simulations in the local shearing box approximation. The simulations self-consistently calculate the heating due to MHD turbulence caused by magneto-rotational instability and radiative cooling by using the radiative transfer module based on a variable Eddington tensor in Athena. For a 5 × 108 solar mass black hole with ∼3% of the Eddington luminosity, a model including the iron opacity bump maintains its structure for more than 10 thermal times without showing significant signs of thermal runaway. In contrast, if only electron scattering and free–free opacity are included as in the standard thin disk model, the disk collapses on the thermal timescale. The difference is caused by a combination of (1) an anti-correlation between the total optical depth and the midplane pressure, and (2) enhanced vertical advective energy transport. These results suggest that the iron opacity bump may have a strong impact on the stability and structure of active galactic nucleus (AGN) accretion disks, and may contribute to a dependence of AGN properties on metallicity. Since this opacity is relevant primarily in UV emitting regions of the flow, it may help to explain discrepancies between observation and theory that are unique to AGNs.

  9. Bump evolution driven by the x-ray ablation Richtmyer-Meshkov effect in plastic inertial confinement fusion Ablators

    NASA Astrophysics Data System (ADS)

    Loomis, Eric; Braun, Dave; Batha, Steven H.; Landen, Otto L.

    2013-11-01

    Growth of hydrodynamic instabilities at the interfaces of inertial confinement fusion capsules (ICF) due to ablator and fuel non-uniformities are a primary concern for the ICF program. Recently, observed jetting and parasitic mix into the fuel were attributed to isolated defects on the outer surface of the capsule. Strategies for mitigation of these defects exist, however, they require reduced uncertainties in Equation of State (EOS) models prior to invoking them. In light of this, we have begun a campaign to measure the growth of isolated defects (bumps) due to x-ray ablation Richtmyer-Meshkov in plastic ablators to validate these models. Experiments used hohlraums with radiation temperatures near 70 eV driven by 15 beams from the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY), which sent a ˜1.25Mbar shock into a planar CH target placed over one laser entrance hole. Targets consisted of 2-D arrays of quasi-gaussian bumps (10 microns tall, 34 microns FWHM) deposited on the surface facing into the hohlraum. On-axis radiography with a saran (Cl Heα - 2.76keV) backlighter was used to measure bump evolution prior to shock breakout. Shock speed measurements were also performed to determine target conditions. Simulations using the LEOS 5310 and SESAME 7592 models required the simulated laser power be turned down to 80 and 88%, respectively to match observed shock speeds. Both LEOS 5310 and SESAME 7592 simulations agreed with measured bump areal densities out to 6 ns where ablative RM oscillations were observed in previous laser-driven experiments, but did not occur in the x-ray driven case. The QEOS model, conversely, over predicted shock speeds and under predicted areal density in the bump.

  10. Precise Countersinking Tool

    NASA Technical Reports Server (NTRS)

    Jenkins, Eric S.; Smith, William N.

    1992-01-01

    Tool countersinks holes precisely with only portable drill; does not require costly machine tool. Replaceable pilot stub aligns axis of tool with centerline of hole. Ensures precise cut even with imprecise drill. Designed for relatively low cutting speeds.

  11. Precision agricultural systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precision agriculture is a new farming practice that has been developing since late 1980s. It has been variously referred to as precision farming, prescription farming, site-specific crop management, to name but a few. There are numerous definitions for precision agriculture, but the central concept...

  12. "Precision" drug development?

    PubMed

    Woodcock, J

    2016-02-01

    The concept of precision medicine has entered broad public consciousness, spurred by a string of targeted drug approvals, highlighted by the availability of personal gene sequences, and accompanied by some remarkable claims about the future of medicine. It is likely that precision medicines will require precision drug development programs. What might such programs look like? PMID:26331240

  13. Bumps of the wave structure function in non-Kolmogorov turbulence

    NASA Astrophysics Data System (ADS)

    Qiao, Chunhong; Lu, Lu; Zhang, Pengfei; Wang, Haitao; Huang, Honghua; Fan, Chengyu

    2015-10-01

    The analytical expressions for wave structure function of plane and spherical waves are derived both in the viscous dissipation and inertial range. Due to previously research, there is a discrepancy between theoretical results and the experimental datum in viscous dissipation range. In this paper, only considering the inertial range, taking plane waves for example, we give a comparison of results of WSF calculated by the analytical formula obtained in this paper and the numerical calculations of the definition at the fixed parameter (i.e., the generalized exponent α), it can be seen that the two results are in agreement with each other exactly. Based on non-Kolmogorov power spectrum, new characteristics for wave structure function (WSF) have been found for plane and spherical wave models when the different ratio of inner scale l0 and outer scale of turbulence L0 is obtained. In outer scale assumed finite case (i.e., L0 =1m), WSF obtains the maximum when α approximates to 3.3 both for plane and spherical wave models. In outer scale assumed infinite case (i.e., L0 = ∞), the WSF can be sorted into three parts, including two rapid-rising regions (i.e., 3.0 < α < 3.3 and 3.8 < α < 4.0 ) and one gently rising region (i.e., 3.3 < α < 3.8 ).Further, the changes of scaled WSF versus the ratio of separation distance and inner scale ( p/ l0 ) are investigated under mentioned above conditions for two models. In L0 = 1m case, both for plane and spherical waves, the value of α determines the bump position of WSF. In L0 = ∞ case, the bump of scaled WSF disappears when the generalized exponent has large values. The changings of scaled WSF monotonically increase as α increased when the generalized exponent is larger than11/3 for two models. Besides, the properties of spherical waves are similar to plane waves, except which the values of WSF and the scaled WSF are smaller than plane ones.

  14. Existence of multi-bump solutions for a class of Kirchhoff type problems in R{sup 3}

    SciTech Connect

    Liang, Sihua; College of Mathematics, Jilin University, Changchun 130012 ; Shi, Shaoyun; Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun 130012

    2013-12-15

    Using variational methods, we establish existence of multi-bump solutions for a class of Kirchhoff type problems −(a+b∫{sub R{sup 3}}|∇u|{sup 2}dx)Δu+λV(x)u=f(u), where f is a continuous function with subcritical growth, V(x) is a critical frequency in the sense that inf{sub x∈R{sup 3}}V(x)=0. We show that if the zero set of V(x) has several isolated connected components Ω{sub 1}, …, Ω{sub k} such that the interior of Ω{sub i} is not empty and ∂Ω{sub i} is smooth, then for λ > 0 large there exists, for any non-empty subset J ⊂ (1, …, k), a bump solution is trapped in a neighborhood of ∪{sub j∈J}Ω{sub j}.

  15. CH4/Ar/H2/SF6 Plasma Etching for Surface Oxide Removal of Indium Bumps

    NASA Astrophysics Data System (ADS)

    Huang, Yue; Lin, Chun; Ye, Zhen-Hua; Liao, Qing-Jun; Ding, Rui-Jun

    2015-07-01

    Plasma etching for surface indium oxide removal by methane/argon/hydrogen/sulfur hexafluoride (CH4/Ar/H2/SF6) mixture has been implemented. The morphology of the indium bumps was not deteriorated after the plasma etching. High-resolution O 1 s x-ray photoelectron spectroscopy (XPS) proved that the In-O component decreased from 44.5% for the nonetched sample to 10.8% for the sample after plasma etching. The surface modification of the indium bumps might be in the form of doped fluorine according to the XPS results. The zero-bias resistance derived from current-voltage ( I- V) measurements for plasma-etched infrared detectors was comparable to that for nonetched ones, indicating that such plasma treatment is suitable for processing sensitive materials such as mercury cadmium telluride.

  16. Precision performance lamp technology

    NASA Astrophysics Data System (ADS)

    Bell, Dean A.; Kiesa, James E.; Dean, Raymond A.

    1997-09-01

    A principal function of a lamp is to produce light output with designated spectra, intensity, and/or geometric radiation patterns. The function of a precision performance lamp is to go beyond these parameters and into the precision repeatability of performance. All lamps are not equal. There are a variety of incandescent lamps, from the vacuum incandescent indictor lamp to the precision lamp of a blood analyzer. In the past the definition of a precision lamp was described in terms of wattage, light center length (LCL), filament position, and/or spot alignment. This paper presents a new view of precision lamps through the discussion of a new segment of lamp design, which we term precision performance lamps. The definition of precision performance lamps will include (must include) the factors of a precision lamp. But what makes a precision lamp a precision performance lamp is the manner in which the design factors of amperage, mscp (mean spherical candlepower), efficacy (lumens/watt), life, not considered individually but rather considered collectively. There is a statistical bias in a precision performance lamp for each of these factors; taken individually and as a whole. When properly considered the results can be dramatic to the system design engineer, system production manage and the system end-user. It can be shown that for the lamp user, the use of precision performance lamps can translate to: (1) ease of system design, (2) simplification of electronics, (3) superior signal to noise ratios, (4) higher manufacturing yields, (5) lower system costs, (6) better product performance. The factors mentioned above are described along with their interdependent relationships. It is statistically shown how the benefits listed above are achievable. Examples are provided to illustrate how proper attention to precision performance lamp characteristics actually aid in system product design and manufacturing to build and market more, market acceptable product products in the

  17. A TALE OF TWO MYSTERIES IN INTERSTELLAR ASTROPHYSICS: THE 2175 A EXTINCTION BUMP AND DIFFUSE INTERSTELLAR BANDS

    SciTech Connect

    Xiang, F. Y.; Zhong, J. X.; Li Aigen E-mail: lia@missouri.edu

    2011-06-01

    The diffuse interstellar bands (DIBs) are ubiquitous absorption spectral features arising from the tenuous material in the space between stars-the interstellar medium (ISM). Since their first detection nearly nine decades ago, over 400 DIBs have been observed in the visible and near-infrared wavelength range in both the Milky Way and external galaxies, both nearby and distant. However, the identity of the species responsible for these bands remains as one of the most enigmatic mysteries in astrophysics. An equally mysterious interstellar spectral signature is the 2175 A extinction bump, the strongest absorption feature observed in the ISM. Its carrier also remains unclear since its first detection 46 years ago. Polycyclic aromatic hydrocarbon (PAH) molecules have long been proposed as a candidate for DIBs as their electronic transitions occur in the wavelength range where DIBs are often found. In recent years, the 2175 A extinction bump is also often attributed to the {pi}-{pi}* transition in PAHs. If PAHs are indeed responsible for both the 2175 A extinction feature and DIBs, their strengths may correlate. We perform an extensive literature search for lines of sight for which both the 2175 A extinction feature and DIBs have been measured. Unfortunately, we found no correlation between the strength of the 2175 A feature and the equivalent widths of the strongest DIBs. A possible explanation might be that DIBs are produced by small free gas-phase PAH molecules and ions, while the 2175 A bump is mainly from large PAHs or PAH clusters in condensed phase so that there is no tight correlation between DIBs and the 2175 A bump.

  18. Blue supergiant model for ultra-long gamma-ray burst with superluminous-supernova-like bump

    SciTech Connect

    Nakauchi, Daisuke; Nakamura, Takashi; Kashiyama, Kazumi; Suwa, Yudai

    2013-11-20

    Long gamma-ray bursts (LGRBs) have a typical duration of ∼30 s, and some of them are associated with hypernovae, such as Type Ic SN 1998bw. Wolf-Rayet stars are the most plausible LGRB progenitors, since the free fall time of the envelope is consistent with the duration, and the natural outcome of the progenitor is a Type Ic SN. While a new population of ultra-long GRBs (ULGRBs), GRB 111209A, GRB 101225A, and GRB 121027A, has a duration of ∼10{sup 4} s, two of them are accompanied by superluminous-supernova-like (SLSN-like) bumps, which are ≲ 10 times brighter than typical hypernovae. Wolf-Rayet progenitors cannot explain ULGRBs because of durations that are too long and SN-like bumps that are too bright. A blue supergiant (BSG) progenitor model, however, can explain the duration of ULGRBs. Moreover, SLSN-like bumps can be attributed to the so-called cocoon fireball photospheric emissions (CFPEs). Since a large cocoon is inevitably produced during the relativistic jet piercing though the BSG envelope, this component can be smoking gun evidence of the BSG model for ULGRBs. In this paper, we examine u-, g-, r-, i-, and J-band light curves of three ULGRBs and demonstrate that they can be fitted quite well by our BSG model with the appropriate choices of the jet opening angle and the number density of the ambient gas. In addition, we predict that for 121027A, SLSN-like bump could have been observed for ∼20-80 days after the burst. We also propose that some SLSNe might be CFPEs of off-axis ULGRBs without visible prompt emissions.

  19. A Tale of Two Mysteries in Interstellar Astrophysics: The 2175 Å Extinction Bump and Diffuse Interstellar Bands

    NASA Astrophysics Data System (ADS)

    Xiang, F. Y.; Li, Aigen; Zhong, J. X.

    2011-06-01

    The diffuse interstellar bands (DIBs) are ubiquitous absorption spectral features arising from the tenuous material in the space between stars—the interstellar medium (ISM). Since their first detection nearly nine decades ago, over 400 DIBs have been observed in the visible and near-infrared wavelength range in both the Milky Way and external galaxies, both nearby and distant. However, the identity of the species responsible for these bands remains as one of the most enigmatic mysteries in astrophysics. An equally mysterious interstellar spectral signature is the 2175 Å extinction bump, the strongest absorption feature observed in the ISM. Its carrier also remains unclear since its first detection 46 years ago. Polycyclic aromatic hydrocarbon (PAH) molecules have long been proposed as a candidate for DIBs as their electronic transitions occur in the wavelength range where DIBs are often found. In recent years, the 2175 Å extinction bump is also often attributed to the π-π* transition in PAHs. If PAHs are indeed responsible for both the 2175 Å extinction feature and DIBs, their strengths may correlate. We perform an extensive literature search for lines of sight for which both the 2175 Å extinction feature and DIBs have been measured. Unfortunately, we found no correlation between the strength of the 2175 Å feature and the equivalent widths of the strongest DIBs. A possible explanation might be that DIBs are produced by small free gas-phase PAH molecules and ions, while the 2175 Å bump is mainly from large PAHs or PAH clusters in condensed phase so that there is no tight correlation between DIBs and the 2175 Å bump.

  20. Gulf Stream-related warm filaments inshore of the Charleston Bump

    NASA Astrophysics Data System (ADS)

    Seim, Harvey; Edwards, Catherine

    2015-04-01

    As the Gulf Stream flows along the shelfbreak of the southeast US it is prone to frontal instabilities. Warm filaments often form along the shelfbreak, extending equatorward from the onshore crests of meanders. Moored current profiler observations, shipboard towed body and current profiler observations, and glider observations collected over the first few months of 2012 are used to describe the structure of energetic warm filaments off the coast of northern South Carolina, USA, inshore of the deflection region of the Gulf Stream known as the Charleston Bump. These filaments were found to extend to more than 100m depth, translate southwestward, and produce strong SW currents (>0.6 m/s at the surface), in contrast to previous studies which documented shallower, non-translating, filaments with weaker currents to the northeast of the study area. Filaments strongly influence the mass field on the outer shelf and upper slope, causing a depression of isosurfaces, possibly enhancing near-bottom offshore flow in frictional boundary layers. A simple geostrophic representation of the near-surface properties of a filament is compared to the observations.

  1. Performance of a cantilever piezoelectric energy harvester impacting a bump stop

    NASA Astrophysics Data System (ADS)

    Mak, Kuok H.; McWilliam, Stewart; Popov, Atanas A.; Fox, Colin H. J.

    2011-12-01

    Piezoelectric cantilever beam energy harvesters are commonly used to convert ambient vibration into electrical energy. In practical applications, energy harvesters are subjected to large shocks which can shorten the service life by causing mechanical failure. In this work, a bump stop is introduced into the design of a piezoelectric cantilever beam energy harvester to limit the maximum displacement of the cantilever and prevent excessively high bending stresses developing as a result of shocks. In addition to limiting the maximum displacement of the beam, it is inevitable that the deflected shape of the beam and the electrical output are modified. A theoretical model for a piezoelectric cantilever beam harvester impacting against a stop is derived, which aims to develop an understanding of the vibration characteristics of the cantilever and quantify how the electrical output of the harvester is affected by the stop. An experiment is set up to measure the dynamics and the electrical output of a bimorph energy harvester and to validate the theoretical model. Numerical simulation results are presented for energy harvesters with different initial gaps and different stop locations, and it is found that the reduction in maximum bending stress is at the expense of the electrical power of the harvester.

  2. The Influential Effect of Blending, Bump, Changing Period, and Eclipsing Cepheids on the Leavitt Law

    NASA Astrophysics Data System (ADS)

    García-Varela, A.; Muñoz, J. R.; Sabogal, B. E.; Vargas Domínguez, S.; Martínez, J.

    2016-06-01

    The investigation of the nonlinearity of the Leavitt law (LL) is a topic that began more than seven decades ago, when some of the studies in this field found that the LL has a break at about 10 days. The goal of this work is to investigate a possible statistical cause of this nonlinearity. By applying linear regressions to OGLE-II and OGLE-IV data, we find that to obtain the LL by using linear regression, robust techniques to deal with influential points and/or outliers are needed instead of the ordinary least-squares regression traditionally used. In particular, by using M- and MM-regressions we establish firmly and without doubt the linearity of the LL in the Large Magellanic Cloud, without rejecting or excluding Cepheid data from the analysis. This implies that light curves of Cepheids suggesting blending, bumps, eclipses, or period changes do not affect the LL for this galaxy. For the Small Magellanic Cloud, when including Cepheids of this kind, it is not possible to find an adequate model, probably because of the geometry of the galaxy. In that case, a possible influence of these stars could exist.

  3. Does recall of a past music event invoke a reminiscence bump in young adults?

    PubMed

    Schubert, Emery

    2016-08-01

    Many studies of the reminiscence bump (RB) in music invoke memories from different autobiographical times by using stimulus specific prompts (SSPs). This study investigated the utility of a non-SSP paradigm to determine whether the RB would emerge when participants were asked to recall a single memorable musical event from "a time long ago". The presence of a RB in response to music has not been obtained in such a manner for younger participants. Eighty-eight 20-22 year olds reported music episodes that peaked when their autobiographical age was 13-14 years. Self-selected stimuli included a range of musical styles, including classical and non-Western pop forms, such as J-pop and K-pop, as well as generational pop music, such as the Beatles. However, most participants reported pop/rock music that was contemporaneous with encoding age, providing support for the utility of published SSP paradigms using pop music. Implications for and limitations of SSP paradigms are discussed. Participants were also asked to relate the selected musical piece to current musical tastes. Most participants liked the music that they selected, with many continuing to like the music, but most also reported a general broadening of their taste, consistent with developmental literature on open-earedness. PMID:26275069

  4. Using a shock control bump to improve the performance of an axial compressor blade section

    NASA Astrophysics Data System (ADS)

    Mazaheri, K.; Khatibirad, S.

    2016-07-01

    Here, we use numerical analysis to study the effects of a shock control bump (SCB) on the performance of a transonic axial compressor blade section and to optimize its shape and location to improve the compressor performance. A section of the NASA rotor 67 blade is used for this study. Two Bézier curves, each consisting of seven control points, are used to model the suction and pressure surfaces of the blade section. The SCB is modeled with the Hicks-Henne function and, using five design parameters, is added to the suction side. The total pressure loss through a cascade of blade sections is selected as the cost function. A continuous adjoint optimization method is used along with a RANS solver to find a new blade section shape. A grid independence study is performed, and all optimization and flow solver algorithms are validated. Two single-point optimizations are performed in the design condition and in an off-design condition. It is shown that both optimized shapes have overall better performance for both on-design and off-design conditions. An analysis is given regarding how the SCB has changed the wave structure between blade sections resulting in a more favorable flow pattern.

  5. An analysis of reservoir storage contents for the proposed enlargement of Bumping Lake in Washington

    USGS Publications Warehouse

    Bartells, John H.

    1981-01-01

    Monthend contents of the proposed Bumping Lake enlargement in Washington were determined for the period 1917-73 by using the historic streamflow record as a basis for inflow to the reservoir and imposing certain operational requirements on reservoir releases. The operational requirements used were those set forth in the Environmental Statement that was prepared for the project by the U.S. Water and Power Resources Service (formerly the U.S. Bureau of Reclamation). The computations show that after starting with an empty reservoir on October 1, 1917, the 458,000 acre-feet capacity of the enlarged lake could be nearly full (384,000 acre-feet) on November 30, 1925, which is the starting scenario given in the Environmental Statement. From 1925 to 1973 the computations compare favorably with those shown in the Environmental Statement, with minor differences due to releases of fish enhancement water. In all cases studied, all fishwater requirements and all existing irrigation requirements were met, and generally from 30,000 to 90,000 acre-feet of extra irrigation water could be available in most years. (USGS)

  6. Effects of Under Bump Metallurgy (UBM) Materials on the Corrosion of Electroless Nickel Films

    NASA Astrophysics Data System (ADS)

    Yu, Jin; Kim, Kyoungdoc

    2015-07-01

    The "black pad" phenomenon, which refers to the blackening of electroless-plated nickel-phosphorus [Ni(P)] films during the immersion Au process, is reproduced using pure chemicals and its fundamental mechanisms are investigated. In the present analysis, under bump metallurgy (UBM) materials have profound effects on the black pad susceptibility, and the presence of abnormally large nodules (ALNs) is essential to the black pad occurrence. The Ni(P) films over Cu, Ag, and Au substrates all exhibit ALNs and are susceptible to black pads, while those over Ni and Co substrates do not have ALNs and therefore are not susceptible to black pad. In the former cases, submicron scale nodular variations of the surface curvature lead to variations in the P concentration in the Ni(P) films, which induces sufficiently large potential differences to drive galvanic corrosion when exposed to the electrolyte, which is a gold cyanide solution in this study. The UBM effect is ascribed to differences in the Ni(P) film growth mode, where the transition from a layer-by-layer growth mode to an island growth mode is easier over Cu, Ag, and Au UBMs.

  7. CAN NEUTRAL AND IONIZED POLYCYCLIC AROMATIC HYDROCARBONS BE CARRIERS OF THE ULTRAVIOLET EXTINCTION BUMP AND THE DIFFUSE INTERSTELLAR BANDS?

    SciTech Connect

    Steglich, M.; Huisken, F.; Bouwman, J.; Henning, Th.

    2011-11-20

    Up to now, no laboratory-based study has investigated polycyclic aromatic hydrocarbon (PAH) species as potential carriers of both the diffuse interstellar bands (DIBs) and the 2175 A UV bump. We examined the proposed correlation between these two features by applying experimental and theoretical techniques on two specific medium-sized/large PAHs (dibenzorubicene C{sub 30}H{sub 14} and hexabenzocoronene C{sub 42}H{sub 18}) in their neutral and cationic states. It was already shown that mixtures of sufficiently large, neutral PAHs can partly or even completely account for the UV bump. We investigated how the absorption bands are altered upon ionization of these molecules by interstellar UV photons. The experimental studies presented here were realized by performing matrix isolation spectroscopy with subsequent far-UV irradiation. The main effects were found to be a broadening of the absorption bands in the UV combined with slight redshifts. The position of the complete {pi}-{pi}* absorption structure around 217.5 nm, however, remains more or less unchanged, which could explain the observed position invariance of the interstellar bump for different lines of sight. This favors the assignment of this feature to the interstellar PAH population. As far as the DIBs are concerned, neither our investigations nor the laboratory studies carried out by other research groups support a possible connection with this class of molecules. Instead, there are reasonable arguments that neutral and singly ionized cationic PAHs cannot be held responsible for the DIBs.

  8. Improving Touschek lifetime in ultralow-emittance lattices through systematic application of successive closed vertical dispersion bumps

    NASA Astrophysics Data System (ADS)

    Breunlin, J.; Leemann, S. C.; Andersson, Å.

    2016-06-01

    In present ultralow-emittance storage ring designs the emittance coupling required for the production of vertically diffraction-limited synchrotron radiation in the hard x-ray regime is achieved and in many cases surpassed by a correction of the orbit and the linear optics alone. However, operating with a vertical emittance lower than required is disadvantageous, since it decreases Touschek lifetime and reduces brightness due to the transverse emittance increase from intrabeam scattering. In this paper we present a scheme consisting of closed vertical dispersion bumps successively excited in each arc of the storage ring by skew quadrupoles that couple horizontal dispersion into the vertical plane to a desired level and thereby raise the vertical emittance in a controlled fashion. A systematic approach to vertical dispersion bumps has been developed that suppresses dispersion and betatron coupling in the straight sections in order to maintain a small projected emittance for insertion devices. In this way, beam lifetime can be significantly increased without negatively impacting insertion device source properties and hence brightness. Using simulation results for the MAX IV 3 GeV storage ring including magnet and alignment imperfections we demonstrate that Touschek lifetime can be increased by more than a factor 2 by adjusting the vertical emittance from 1.3 pm rad (after orbit correction) to 8 pm rad (after application of dispersion bumps) using two to three independent skew quadrupole families all the while ensuring deviations from design optics are restrained to a minimum.

  9. Advanced irrigation engineering: Precision and Precise

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation advances in precision irrigation (PI) or site-specific irrigation (SSI) have been considerable in research; however commercialization lags. A primary necessity for it is variability in soil texture that affects soil water holding capacity and crop yield. Basically, SSI/PI uses variable ra...

  10. Advanced irrigation engineering: Precision and Precise

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation advances in precision irrigation (PI) or site specific irrigation (SSI) have been considerable in research; however commercialization lags. A primary necessity for PI/SSI is variability in soil texture that affects soil water holding capacity and crop yield. Basically, SSI/PI uses variabl...

  11. Control of flow separation on a contour bump by jets in a Mach 1.9 free-stream: An experimental study

    NASA Astrophysics Data System (ADS)

    Lo, Kin Hing; Zare-Behtash, Hossein; Kontis, Konstantinos

    2016-09-01

    Flow separation control over a three-dimensional contour bump using jet in a Mach 1.9 supersonic free-stream has been experimentally investigated using a transonic/supersonic wind tunnel. Jet total pressure in the range of 0-4 bar was blowing at the valley of the contour bump. Schlieren photography, surface oil flow visualisation and particle image velocimetry measurements were employed for flow visualisation and diagnostics. Experimental results show that blowing jet at the valley of the contour bump can hinder the formation and distort the spanwise vortices. The blowing jet can also reduce the extent of flow separation appears downstream of the bump crest. It was observed that this approach of flow control is more effective when high jet total pressure is employed. It is believed that a pressure gradient is generated as a result of the interaction between the flow downstream of the bump crest and the jet induced shock leads to the downwards flow motion around the bump valley.

  12. Coal mine bumps as related to geologic features in the northern part of the Sunnyside District, Carbon County, Utah

    USGS Publications Warehouse

    Osterwald, Frank W.; Dunrud, C. Richard; Collins, Donley S.

    1993-01-01

    Coal mine bumps, which are violent, spontaneous, and often catastrophic disruptions of coal and rock, were common in the Sunnyside coal mining district, Utah, before the introduction of protective-engineering methods, modern room-and-pillar retreat mining with continuous mining machines, and particularly modern longwall mining. The coal at Sunnyside, when stressed during mining, fails continuously with many popping, snapping, and banging noises. Although most of the bumps are beneficial because they make mining easier, many of the large ones are dangerous and in the past caused injuries and fatalities, particularly with room- and-pillar mining methods used in the early mining operations. Geologic mapping of underground mine openings revealed many types of deformational features, some pre-mine and some post-mine in age. Stresses resulting from mining are concentrated near the mine openings; if openings are driven at large angles to small pre-mine deformational features, particularly shatter zones in coal, abnormal stress buildups may occur and violent bumps may result. Other geologic features, such as ripple marks, oriented sand grains, intertongued rock contacts, trace fossils, and load casts, also influence the occurrence of bumps by impeding slip of coal and rocks along bedding planes. The stress field in the coal also varies markedly because of the rough ridge and canyon topography. These features may allow excessively large stress components to accumulate. At many places, the stresses that contribute to deformation and failures of mine openings are oriented horizontally. The stratigraphy of the rocks immediately above and below the mined coal bed strongly influences the deformation of the mine openings in response to stress accumulations. Triaxial compressive testing of coal from the Sunnyside No.1 and No.3 Mines indicates that the strength of the coal increases several times as the confining (lateral) stress is increased. Strengths of cores cut from single

  13. Precision Optics Curriculum.

    ERIC Educational Resources Information Center

    Reid, Robert L.; And Others

    This guide outlines the competency-based, two-year precision optics curriculum that the American Precision Optics Manufacturers Association has proposed to fill the void that it suggests will soon exist as many of the master opticians currently employed retire. The model, which closely resembles the old European apprenticeship model, calls for 300…

  14. Improving the precision matrix for precision cosmology

    NASA Astrophysics Data System (ADS)

    Paz, Dante J.; Sánchez, Ariel G.

    2015-12-01

    The estimation of cosmological constraints from observations of the large-scale structure of the Universe, such as the power spectrum or the correlation function, requires the knowledge of the inverse of the associated covariance matrix, namely the precision matrix, Ψ . In most analyses, Ψ is estimated from a limited set of mock catalogues. Depending on how many mocks are used, this estimation has an associated error which must be propagated into the final cosmological constraints. For future surveys such as Euclid and Dark Energy Spectroscopic Instrument, the control of this additional uncertainty requires a prohibitively large number of mock catalogues. In this work, we test a novel technique for the estimation of the precision matrix, the covariance tapering method, in the context of baryon acoustic oscillation measurements. Even though this technique was originally devised as a way to speed up maximum likelihood estimations, our results show that it also reduces the impact of noisy precision matrix estimates on the derived confidence intervals, without introducing biases on the target parameters. The application of this technique can help future surveys to reach their true constraining power using a significantly smaller number of mock catalogues.

  15. Precision enhancement of pavement roughness localization with connected vehicles

    NASA Astrophysics Data System (ADS)

    Bridgelall, R.; Huang, Y.; Zhang, Z.; Deng, F.

    2016-02-01

    Transportation agencies rely on the accurate localization and reporting of roadway anomalies that could pose serious hazards to the traveling public. However, the cost and technical limitations of present methods prevent their scaling to all roadways. Connected vehicles with on-board accelerometers and conventional geospatial position receivers offer an attractive alternative because of their potential to monitor all roadways in real-time. The conventional global positioning system is ubiquitous and essentially free to use but it produces impractically large position errors. This study evaluated the improvement in precision achievable by augmenting the conventional geo-fence system with a standard speed bump or an existing anomaly at a pre-determined position to establish a reference inertial marker. The speed sensor subsequently generates position tags for the remaining inertial samples by computing their path distances relative to the reference position. The error model and a case study using smartphones to emulate connected vehicles revealed that the precision in localization improves from tens of metres to sub-centimetre levels, and the accuracy of measuring localized roughness more than doubles. The research results demonstrate that transportation agencies will benefit from using the connected vehicle method to achieve precision and accuracy levels that are comparable to existing laser-based inertial profilers.

  16. Precision liquid level sensor

    DOEpatents

    Field, M.E.; Sullivan, W.H.

    A precision liquid level sensor utilizes a balanced bridge, each arm including an air dielectric line. Changes in liquid level along one air dielectric line imbalance the bridge and create a voltage which is directly measurable across the bridge.

  17. Precision digital control systems

    NASA Astrophysics Data System (ADS)

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  18. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F.; Dubois, Robert R.; Strother, Jerry D.

    2000-02-22

    A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

  19. Hermetic integration of liquids using high-speed stud bump bonding for cavity sealing at the wafer level

    NASA Astrophysics Data System (ADS)

    Antelius, Mikael; Fischer, Andreas C.; Niklaus, Frank; Stemme, Göran; Roxhed, Niclas

    2012-04-01

    This paper reports a novel room-temperature hermetic liquid sealing process where the access ports of liquid-filled cavities are sealed with wire-bonded stud bumps. This process enables liquids to be integrated at the fabrication stage. Evaluation cavities were manufactured and used to investigate the mechanical and hermetic properties of the seals. Measurements on the successfully sealed structures show a helium leak rate of better than 10-10 mbarL s-1, in addition to a zero liquid loss over two months during storage near boiling temperature. The bond strength of the plugs was similar to standard wire bonds on flat surfaces.

  20. Estimating sparse precision matrices

    NASA Astrophysics Data System (ADS)

    Padmanabhan, Nikhil; White, Martin; Zhou, Harrison H.; O'Connell, Ross

    2016-08-01

    We apply a method recently introduced to the statistical literature to directly estimate the precision matrix from an ensemble of samples drawn from a corresponding Gaussian distribution. Motivated by the observation that cosmological precision matrices are often approximately sparse, the method allows one to exploit this sparsity of the precision matrix to more quickly converge to an asymptotic 1/sqrt{N_sim} rate while simultaneously providing an error model for all of the terms. Such an estimate can be used as the starting point for further regularization efforts which can improve upon the 1/sqrt{N_sim} limit above, and incorporating such additional steps is straightforward within this framework. We demonstrate the technique with toy models and with an example motivated by large-scale structure two-point analysis, showing significant improvements in the rate of convergence. For the large-scale structure example, we find errors on the precision matrix which are factors of 5 smaller than for the sample precision matrix for thousands of simulations or, alternatively, convergence to the same error level with more than an order of magnitude fewer simulations.

  1. Estimating sparse precision matrices

    NASA Astrophysics Data System (ADS)

    Padmanabhan, Nikhil; White, Martin; Zhou, Harrison H.; O'Connell, Ross

    2016-05-01

    We apply a method recently introduced to the statistical literature to directly estimate the precision matrix from an ensemble of samples drawn from a corresponding Gaussian distribution. Motivated by the observation that cosmological precision matrices are often approximately sparse, the method allows one to exploit this sparsity of the precision matrix to more quickly converge to an asymptotic 1/√{N_sim} rate while simultaneously providing an error model for all of the terms. Such an estimate can be used as the starting point for further regularization efforts which can improve upon the 1/√{N_sim} limit above, and incorporating such additional steps is straightforward within this framework. We demonstrate the technique with toy models and with an example motivated by large-scale structure two-point analysis, showing significant improvements in the rate of convergence. For the large-scale structure example we find errors on the precision matrix which are factors of 5 smaller than for the sample precision matrix for thousands of simulations or, alternatively, convergence to the same error level with more than an order of magnitude fewer simulations.

  2. Estimating sparse precision matrices

    NASA Astrophysics Data System (ADS)

    Padmanabhan, Nikhil; White, Martin; Zhou, Harrison H.; O'Connell, Ross

    2016-08-01

    We apply a method recently introduced to the statistical literature to directly estimate the precision matrix from an ensemble of samples drawn from a corresponding Gaussian distribution. Motivated by the observation that cosmological precision matrices are often approximately sparse, the method allows one to exploit this sparsity of the precision matrix to more quickly converge to an asymptotic 1/√{N_sim} rate while simultaneously providing an error model for all of the terms. Such an estimate can be used as the starting point for further regularization efforts which can improve upon the 1/√{N_sim} limit above, and incorporating such additional steps is straightforward within this framework. We demonstrate the technique with toy models and with an example motivated by large-scale structure two-point analysis, showing significant improvements in the rate of convergence. For the large-scale structure example, we find errors on the precision matrix which are factors of 5 smaller than for the sample precision matrix for thousands of simulations or, alternatively, convergence to the same error level with more than an order of magnitude fewer simulations.

  3. Precision Higgs Physics

    NASA Astrophysics Data System (ADS)

    Boughezal, Radja

    2015-04-01

    The future of the high energy physics program will increasingly rely upon precision studies looking for deviations from the Standard Model. Run I of the Large Hadron Collider (LHC) triumphantly discovered the long-awaited Higgs boson, and there is great hope in the particle physics community that this new state will open a portal onto a new theory of Nature at the smallest scales. A precision study of Higgs boson properties is needed in order to test whether this belief is true. New theoretical ideas and high-precision QCD tools are crucial to fulfill this goal. They become even more important as larger data sets from LHC Run II further reduce the experimental errors and theoretical uncertainties begin to dominate. In this talk, I will review recent progress in understanding Higgs properties,including the calculation of precision predictions needed to identify possible physics beyond the Standard Model in the Higgs sector. New ideas for measuring the Higgs couplings to light quarks as well as bounding the Higgs width in a model-independent way will be discussed. Precision predictions for Higgs production in association with jets and ongoing efforts to calculate the inclusive N3LO cross section will be reviewed.

  4. Precision gap particle separator

    DOEpatents

    Benett, William J.; Miles, Robin; Jones, II., Leslie M.; Stockton, Cheryl

    2004-06-08

    A system for separating particles entrained in a fluid includes a base with a first channel and a second channel. A precision gap connects the first channel and the second channel. The precision gap is of a size that allows small particles to pass from the first channel into the second channel and prevents large particles from the first channel into the second channel. A cover is positioned over the base unit, the first channel, the precision gap, and the second channel. An port directs the fluid containing the entrained particles into the first channel. An output port directs the large particles out of the first channel. A port connected to the second channel directs the small particles out of the second channel.

  5. Precision Muonium Spectroscopy

    NASA Astrophysics Data System (ADS)

    Jungmann, Klaus P.

    2016-09-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 µs. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular ground state hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s-2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular quantum electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium-antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter.

  6. How Physics Got Precise

    SciTech Connect

    Kleppner, Daniel

    2005-01-19

    Although the ancients knew the length of the year to about ten parts per million, it was not until the end of the 19th century that precision measurements came to play a defining role in physics. Eventually such measurements made it possible to replace human-made artifacts for the standards of length and time with natural standards. For a new generation of atomic clocks, time keeping could be so precise that the effects of the local gravitational potentials on the clock rates would be important. This would force us to re-introduce an artifact into the definition of the second - the location of the primary clock. I will describe some of the events in the history of precision measurements that have led us to this pleasing conundrum, and some of the unexpected uses of atomic clocks today.

  7. Dynamics and afterglow light curves of gamma-ray burst blast waves encountering a density bump or void

    SciTech Connect

    Uhm, Z. Lucas; Zhang, Bing E-mail: zhang@physics.unlv.edu

    2014-07-01

    We investigate the dynamics and afterglow light curves of gamma-ray burst blast waves that encounter various density structures (such as bumps, voids, or steps) in the surrounding ambient medium. We present and explain the characteristic response features that each type of density structure in the medium leaves on the forward shock (FS) and reverse shock (RS) dynamics for blast waves with either a long-lived or short-lived RS. We show that when the ambient medium density drops, the blast waves exhibit in some cases a period of an actual acceleration (even during their deceleration stage) due to adiabatic cooling of blast waves. Comparing numerical examples that have different shapes of bumps or voids, we propose a number of consistency tests that must be satisfied by correct modeling of blast waves. Our model results successfully pass these tests. Employing a Lagrangian description of blast waves, we perform a sophisticated calculation of afterglow emission. We show that as a response to density structures in the ambient medium, the RS light curves produce more significant variations than the FS light curves. Some observed features (such as rebrightenings, dips, or slow wiggles) can be more easily explained within the RS model. We also discuss the origin of these different features imprinted on the FS and RS light curves.

  8. Dynamics and Afterglow Light Curves of Gamma-Ray Burst Blast Waves Encountering a Density Bump or Void

    NASA Astrophysics Data System (ADS)

    Uhm, Z. Lucas; Zhang, Bing

    2014-07-01

    We investigate the dynamics and afterglow light curves of gamma-ray burst blast waves that encounter various density structures (such as bumps, voids, or steps) in the surrounding ambient medium. We present and explain the characteristic response features that each type of density structure in the medium leaves on the forward shock (FS) and reverse shock (RS) dynamics for blast waves with either a long-lived or short-lived RS. We show that when the ambient medium density drops, the blast waves exhibit in some cases a period of an actual acceleration (even during their deceleration stage) due to adiabatic cooling of blast waves. Comparing numerical examples that have different shapes of bumps or voids, we propose a number of consistency tests that must be satisfied by correct modeling of blast waves. Our model results successfully pass these tests. Employing a Lagrangian description of blast waves, we perform a sophisticated calculation of afterglow emission. We show that as a response to density structures in the ambient medium, the RS light curves produce more significant variations than the FS light curves. Some observed features (such as rebrightenings, dips, or slow wiggles) can be more easily explained within the RS model. We also discuss the origin of these different features imprinted on the FS and RS light curves.

  9. Impulsive plunging wave breaking downstream of a bump in a shallow water flume—Part I: Experimental observations

    NASA Astrophysics Data System (ADS)

    Kang, Donghoon; Ghosh, Surajeet; Reins, George; Koo, Bonguk; Wang, Zhaoyuan; Stern, Frederick

    2012-07-01

    The plunging wave-breaking process for impulsive flow over a bump in a shallow water flume is described, which is relevant to ship hydrodynamics albeit for an idealized geometry since it includes the effects of wave-body interactions and the wave breaking direction is opposite to the mean flow. This paper consists of two parts, which deal with experimental measurements and numerical simulations, respectively. In Part I, ensemble-averaged measurements are conducted, including the overall flume flow, 2-D particle image velocimetry (PIV) center-plane velocities, turbulence inside the breaking wave, and bottom pressures under the breaking wave. A series of individual plunging wave-breaking tests were conducted, which all followed a similar time line consisting of startup, steep wave formation, plunging wave breaking, and chaotic wave breaking swept downstream time phases. The plunging wave breaking process consists of four repeated plunging events each with three [jet impact (plunge), oblique splash and vertical jet] sub-events, which were identified first using a complementary computational fluid dynamics (CFD) study. Video images with red dye display the plunging wave breaking events and sub-events. The wave profile at maximum height, first plunge, bump and wave breaking vortex and entrapped air tube trajectories, entrapped air tube diameters, kinetic, potential, and total energy are analyzed. Similarities and differences are discussed with the previous deep water or sloping beach experimental and computational studies. The numerical simulations using the exact experimental initial and boundary conditions are presented in Part II of this paper.

  10. Precision Nova operations

    SciTech Connect

    Ehrlich, R.B.; Miller, J.L.; Saunders, R.L.; Thompson, C.E.; Weiland, T.L.; Laumann, C.W.

    1995-09-01

    To improve the symmetry of x-ray drive on indirectly driven ICF capsules, we have increased the accuracy of operating procedures and diagnostics on the Nova laser. Precision Nova operations includes routine precision power balance to within 10% rms in the ``foot`` and 5% nns in the peak of shaped pulses, beam synchronization to within 10 ps rms, and pointing of the beams onto targets to within 35 {mu}m rms. We have also added a ``fail-safe chirp`` system to avoid Stimulated Brillouin Scattering (SBS) in optical components during high energy shots.

  11. Precision electron polarimetry

    SciTech Connect

    Chudakov, Eugene A.

    2013-11-01

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\\%-polarized electron target for M{\\o}ller polarimetry.

  12. Precision electron polarimetry

    SciTech Connect

    Chudakov, E.

    2013-11-07

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. Mo/ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at 300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100%-polarized electron target for Mo/ller polarimetry.

  13. Precision Heating Process

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A heat sealing process was developed by SEBRA based on technology that originated in work with NASA's Jet Propulsion Laboratory. The project involved connecting and transferring blood and fluids between sterile plastic containers while maintaining a closed system. SEBRA markets the PIRF Process to manufacturers of medical catheters. It is a precisely controlled method of heating thermoplastic materials in a mold to form or weld catheters and other products. The process offers advantages in fast, precise welding or shape forming of catheters as well as applications in a variety of other industries.

  14. Precision Nova operations

    NASA Astrophysics Data System (ADS)

    Ehrlich, Robert B.; Miller, John L.; Saunders, Rodney L.; Thompson, Calvin E.; Weiland, Timothy L.; Laumann, Curt W.

    1995-12-01

    To improve the symmetry of x-ray drive on indirectly driven ICF capsules, we have increased the accuracy of operating procedures and diagnostics on the Nova laser. Precision Nova operations include routine precision power balance to within 10% rms in the 'foot' and 5% rms in the peak of shaped pulses, beam synchronization to within 10 ps rms, and pointing of the beams onto targets to within 35 micrometer rms. We have also added a 'fail-safe chirp' system to avoid stimulated Brillouin scattering (SBS) in optical components during high energy shots.

  15. Precision manometer gauge

    DOEpatents

    McPherson, M.J.; Bellman, R.A.

    1982-09-27

    A precision manometer gauge which locates a zero height and a measured height of liquid using an open tube in communication with a reservoir adapted to receive the pressure to be measured. The open tube has a reference section carried on a positioning plate which is moved vertically with machine tool precision. Double scales are provided to read the height of the positioning plate accurately, the reference section being inclined for accurate meniscus adjustment, and means being provided to accurately locate a zero or reference position.

  16. Precision manometer gauge

    DOEpatents

    McPherson, Malcolm J.; Bellman, Robert A.

    1984-01-01

    A precision manometer gauge which locates a zero height and a measured height of liquid using an open tube in communication with a reservoir adapted to receive the pressure to be measured. The open tube has a reference section carried on a positioning plate which is moved vertically with machine tool precision. Double scales are provided to read the height of the positioning plate accurately, the reference section being inclined for accurate meniscus adjustment, and means being provided to accurately locate a zero or reference position.

  17. Precision in Stereochemical Terminology

    ERIC Educational Resources Information Center

    Wade, Leroy G., Jr.

    2006-01-01

    An analysis of relatively new terminology that has given multiple definitions often resulting in students learning principles that are actually false is presented with an example of the new term stereogenic atom introduced by Mislow and Siegel. The Mislow terminology would be useful in some cases if it were used precisely and correctly, but it is…

  18. Precision bolometer bridge

    NASA Technical Reports Server (NTRS)

    White, D. R.

    1968-01-01

    Prototype precision bolometer calibration bridge is manually balanced device for indicating dc bias and balance with either dc or ac power. An external galvanometer is used with the bridge for null indication, and the circuitry monitors voltage and current simultaneously without adapters in testing 100 and 200 ohm thin film bolometers.

  19. Precision metal molding

    NASA Technical Reports Server (NTRS)

    Townhill, A.

    1967-01-01

    Method provides precise alignment for metal-forming dies while permitting minimal thermal expansion without die warpage or cavity space restriction. The interfacing dowel bars and die side facings are arranged so the dies are restrained in one orthogonal angle and permitted to thermally expand in the opposite orthogonal angle.

  20. Precision liquid level sensor

    DOEpatents

    Field, M.E.; Sullivan, W.H.

    1985-01-29

    A precision liquid level sensor utilizes a balanced R. F. bridge, each arm including an air dielectric line. Changes in liquid level along one air dielectric line imbalance the bridge and create a voltage which is directly measurable across the bridge. 2 figs.

  1. Precision liquid level sensor

    DOEpatents

    Field, Michael E.; Sullivan, William H.

    1985-01-01

    A precision liquid level sensor utilizes a balanced R. F. bridge, each arm including an air dielectric line. Changes in liquid level along one air dielectric line imbalance the bridge and create a voltage which is directly measurable across the bridge.

  2. Precision physics at LHC

    SciTech Connect

    Hinchliffe, I.

    1997-05-01

    In this talk the author gives a brief survey of some physics topics that will be addressed by the Large Hadron Collider currently under construction at CERN. Instead of discussing the reach of this machine for new physics, the author gives examples of the types of precision measurements that might be made if new physics is discovered.

  3. Self-similar bumps and wiggles: Isolating the evolution of the BAO peak with power-law initial conditions

    NASA Astrophysics Data System (ADS)

    Orban, Chris; Weinberg, David H.

    2011-09-01

    Motivated by cosmological surveys that demand accurate theoretical modeling of the baryon acoustic oscillation (BAO) feature in galaxy clustering, we analyze N-body simulations in which a BAO-like Gaussian bump modulates the linear theory correlation function ξL(r)=(r0/r)n+3 of an underlying self-similar model with initial power spectrum P(k)=Akn. These simulations test physical and analytic descriptions of BAO evolution far beyond the range of most studies, since we consider a range of underlying power spectra (n=-0.5, -1, -1.5) and evolve simulations to large effective correlation amplitudes (equivalent to σ8=4-12 for rbao=100h-1Mpc). In all cases, nonlinear evolution flattens and broadens the BAO bump in ξ(r) while approximately preserving its area. This evolution resembles a diffusion process in which the bump width σbao is the quadrature sum of the linear theory width and a length proportional to the rms relative displacement Σpair(rbao) of particle pairs separated by rbao. For n=-0.5 and n=-1, we find no detectable shift of the location of the BAO peak, but the peak in the n=-1.5 model shifts steadily to smaller scales, following rpeak/rbao=1-1.08(r0/rbao)1.5. The perturbation theory scheme of McDonald (2007) [P. McDonald, Phys. Rev. DPRVDAQ1550-7998 75, 043514 (2007).10.1103/PhysRevD.75.043514] and, to a lesser extent, standard 1-loop perturbation theory are fairly successful at explaining the nonlinear evolution of the Fourier power spectrum of our models. Analytic models also explain why the ξ(r) peak shifts much more for n=-1.5 than for n≥-1, though no ab initio model we have examined reproduces all of our numerical results. Simulations with Lbox=10rbao and Lbox=20rbao yield consistent results for ξ(r) at the BAO scale, provided one corrects for the integral constraint imposed by the uniform density box.

  4. Precision Polarization of Neutrons

    NASA Astrophysics Data System (ADS)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  5. Precision synchrotron radiation detectors

    SciTech Connect

    Levi, M.; Rouse, F.; Butler, J.; Jung, C.K.; Lateur, M.; Nash, J.; Tinsman, J.; Wormser, G.; Gomez, J.J.; Kent, J.

    1989-03-01

    Precision detectors to measure synchrotron radiation beam positions have been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 /mu/m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely-aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. Also, detectors of synchrotron radiation using the charge developed by the ejection of Compton-recoil electrons from an array of fine wires are being developed. 4 refs., 5 figs., 1 tab.

  6. A passion for precision

    SciTech Connect

    2010-05-19

    For more than three decades, the quest for ever higher precision in laser spectroscopy of the simple hydrogen atom has inspired many advances in laser, optical, and spectroscopic techniques, culminating in femtosecond laser optical frequency combs  as perhaps the most precise measuring tools known to man. Applications range from optical atomic clocks and tests of QED and relativity to searches for time variations of fundamental constants. Recent experiments are extending frequency comb techniques into the extreme ultraviolet. Laser frequency combs can also control the electric field of ultrashort light pulses, creating powerful new tools for the emerging field of attosecond science.Organiser(s): L. Alvarez-Gaume / PH-THNote: * Tea & coffee will be served at 16:00.

  7. Towards precision medicine.

    PubMed

    Ashley, Euan A

    2016-08-16

    There is great potential for genome sequencing to enhance patient care through improved diagnostic sensitivity and more precise therapeutic targeting. To maximize this potential, genomics strategies that have been developed for genetic discovery - including DNA-sequencing technologies and analysis algorithms - need to be adapted to fit clinical needs. This will require the optimization of alignment algorithms, attention to quality-coverage metrics, tailored solutions for paralogous or low-complexity areas of the genome, and the adoption of consensus standards for variant calling and interpretation. Global sharing of this more accurate genotypic and phenotypic data will accelerate the determination of causality for novel genes or variants. Thus, a deeper understanding of disease will be realized that will allow its targeting with much greater therapeutic precision. PMID:27528417

  8. A passion for precision

    ScienceCinema

    None

    2011-10-06

    For more than three decades, the quest for ever higher precision in laser spectroscopy of the simple hydrogen atom has inspired many advances in laser, optical, and spectroscopic techniques, culminating in femtosecond laser optical frequency combs  as perhaps the most precise measuring tools known to man. Applications range from optical atomic clocks and tests of QED and relativity to searches for time variations of fundamental constants. Recent experiments are extending frequency comb techniques into the extreme ultraviolet. Laser frequency combs can also control the electric field of ultrashort light pulses, creating powerful new tools for the emerging field of attosecond science.Organiser(s): L. Alvarez-Gaume / PH-THNote: * Tea & coffee will be served at 16:00.

  9. An Extended Keyword Extraction Method

    NASA Astrophysics Data System (ADS)

    Hong, Bao; Zhen, Deng

    Among numerous Chinese keyword extraction methods, Chinese characteristics were shortly considered. This phenomenon going against the precision enhancement of the Chinese keyword extraction. An extended term frequency based method(Extended TF) is proposed in this paper which combined Chinese linguistic characteristics with basic TF method. Unary, binary and ternary grammars for the candidate keyword extraction as well as other linguistic features were all taken into account. The method establishes classification model using support vector machine. Tests show that the proposed extraction method improved key words precision and recall rate significantly. We applied the key words extracted by the extended TF method into the text file classification. Results show that the key words extracted by the proposed method contributed greatly to raising the precision of text file classification.

  10. Precision laser aiming system

    SciTech Connect

    Ahrens, Brandon R.; Todd, Steven N.

    2009-04-28

    A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.