Science.gov

Sample records for alternative assembly pushes

  1. Serial pushing model for the self-assembly in dip-pen nanolithography.

    PubMed

    Kim, Hyojeong; Jang, Joonkyung

    2009-04-23

    Based on the findings of molecular dynamics simulations, we propose a novel diffusion model for the self-assembly in dip-pen nanolithography. A central question in such modeling is how a nascent droplet created below an AFM tip spreads out to form a self-assembled monolayer (SAM) on a substrate later. In the present model, a molecule dropping from the tip pushes a molecule on the substrate out of its original position, and the molecule pushed out in turn pushes its own neighbor. A SAM grows through such a series of push-induced movements. The initial pushing propagates all the way to the periphery where there is no molecule to push out. By contrast, according to the previous hopping-down model, a molecule moves by stepping over molecules trapped on the substrate and occasionally hops down to the substrate. By implementing our model in random walk simulations, we study the structure and growth dynamics of the SAM generated by a fixed tip and the lines and characters created by a moving tip. We investigate how the SAM is influenced by the molecular dripping rate and tip scan speed. Compared to the hopping model, the present model gives a SAM growing faster and more fluctuating in its periphery. A salient feature of our model is its ability to generate various SAMs by changing the directional coherence length of the push-induced displacement. If we choose the coherence length to be zero, each push-induced displacement is random in direction to give a compact circular SAM. As the directional coherence length increases, the SAM becomes a noncircular pattern with distinct branches. In the limit of an infinite coherence length, the SAM becomes a long narrow cross due to the substrate anisotropy.

  2. Push plate, mounting assembly, circuit board, and method of assembling thereof for ball grid array packages

    SciTech Connect

    Vaughn, Mark R.; Montague, Stephen

    2017-05-16

    A push plate that includes springs in the form of cantilever flexures and an inspection window is disclosed. The push plate provides a known, uniform, down force and minimal torque to a package to be tested. The cantilevers have a known, calculable down force producing stiffness. The window provides for viewing of the package during testing.

  3. Manipulation and assembly of small objects in liquid crystals by dynamical disorganizing effect of push-pull-azobenzene-dye.

    PubMed

    Kurihara, Seiji; Ohta, Kazuhiro; Oda, Takahiro; Izumi, Ryo; Kuwahara, Yutaka; Ogata, Tomonari; Kim, Sun-Nam

    2013-01-01

    The phase transition of a nematic liquid crystal containing a push-pull azobenzene dye could be induced efficiently during irradiation with visible light. The dynamical disorganizing effect of the push-pull azobenzene dye on the liquid crystalline order through its trans-cis-trans photoisomerizaion cycle under visible light was contributed to the efficient phase transition. Then, the effects of light irradiation on the motion of small objects dispersed in the liquid crystals containing the push-pull azobenzene were explored, and the manipulation and assembly of those objects were successfully achieved in the nematic phase but also in the smectic phase. The combination of the photo-controlled dynamical change in the liquid crystalline order and the intrinsic self-assembly property of a liquid crystal is promising for use in technologies that require not only the organization of small objects but also the photo-driving of nano- and micro-sized mechanical materials.

  4. Manipulation and assembly of small objects in liquid crystals by dynamical disorganizing effect of push-pull-azobenzene-dye

    PubMed Central

    Kurihara, Seiji; Ohta, Kazuhiro; Oda, Takahiro; Izumi, Ryo; Kuwahara, Yutaka; Ogata, Tomonari; Kim, Sun-Nam

    2013-01-01

    The phase transition of a nematic liquid crystal containing a push-pull azobenzene dye could be induced efficiently during irradiation with visible light. The dynamical disorganizing effect of the push-pull azobenzene dye on the liquid crystalline order through its trans-cis-trans photoisomerizaion cycle under visible light was contributed to the efficient phase transition. Then, the effects of light irradiation on the motion of small objects dispersed in the liquid crystals containing the push-pull azobenzene were explored, and the manipulation and assembly of those objects were successfully achieved in the nematic phase but also in the smectic phase. The combination of the photo-controlled dynamical change in the liquid crystalline order and the intrinsic self-assembly property of a liquid crystal is promising for use in technologies that require not only the organization of small objects but also the photo-driving of nano- and micro-sized mechanical materials. PMID:23835605

  5. Let's push things forward: disruptive technologies and the mechanics of tissue assembly.

    PubMed

    Varner, Victor D; Nelson, Celeste M

    2013-09-01

    Although many of the molecular mechanisms that regulate tissue assembly in the embryo have been delineated, the physical forces that couple these mechanisms to actual changes in tissue form remain unclear. Qualitative studies suggest that mechanical loads play a regulatory role in development, but clear quantitative evidence has been lacking. This is partly owing to the complex nature of these problems - embryonic tissues typically undergo large deformations and exhibit evolving, highly viscoelastic material properties. Still, despite these challenges, new disruptive technologies are enabling study of the mechanics of tissue assembly in unprecedented detail. Here, we present novel experimental techniques that enable the study of each component of these physical problems: kinematics, forces, and constitutive properties. Specifically, we detail advances in light sheet microscopy, optical coherence tomography, traction force microscopy, fluorescence force spectroscopy, microrheology and micropatterning. Taken together, these technologies are helping elucidate a more quantitative understanding of the mechanics of tissue assembly.

  6. Alternating current electrohydrodynamics in microsystems: Pushing biomolecules and cells around on surfaces

    PubMed Central

    Vaidyanathan, Ramanathan; Dey, Shuvashis; Carrascosa, Laura G.; Shiddiky, Muhammad J. A.; Trau, Matt

    2015-01-01

    Electrohydrodynamics (EHD) deals with the fluid motion induced by an electric field. This phenomenon originally developed in physical science, and engineering is currently experiencing a renaissance in microfluidics. Investigations by Taylor on Gilbert's theory proposed in 1600 have evolved to include multiple contributions including the promising effects arising from electric field interactions with cells and particles to influence their behaviour on electrode surfaces. Theoretical modelling of electric fields in microsystems and the ability to determine shear forces have certainly reached an advanced state. The ability to deftly manipulate microscopic fluid flow in bulk fluid and at solid/liquid interfaces has enabled the controlled assembly, coagulation, or removal of microstructures, nanostructures, cells, and molecules on surfaces. Furthermore, the ability of electrohydrodynamics to generate fluid flow using surface shear forces generated within nanometers from the surface and their application in bioassays has led to recent advancements in biomolecule, vesicle and cellular detection across different length scales. With the integration of Alternating Current Electrohydrodynamics (AC-EHD) in cellular and molecular assays proving to be highly fruitful, challenges still remain with respect to understanding the discrepancies between each of the associated ac-induced fluid flow phenomena, extending their utility towards clinical diagnostic development, and utilising them in tandem as a standard tool for disease monitoring. In this regard, this article will review the history of electrohydrodynamics, followed by some of the recent developments in the field including a new dimension of electrohydrodynamics that deals with the utilization of surface shear forces for the manipulation of biological cells or molecules on electrode surfaces. Recent advances and challenges in the use of electrohydrodynamic forces such as dielectrophoresis and ac electrosmosis for the

  7. Pulled in or pushed out? Understanding the complexities of motivation for alternative therapies use in Ghana

    PubMed Central

    Gyasi, Razak Mohammed; Asante, Felix; Yeboah, Joseph Yaw; Abass, Kabila; Mensah, Charlotte Monica; Siaw, Lawrencia Pokuah

    2016-01-01

    The impact of strong cultural beliefs on specific reasons for traditional medicine (TRM) use among individuals and populations has long been advanced in health care and spatio-medical literature. Yet, little has been done in Ghana and the Ashanti Region in particular to bring out the precise “pull” and “push” relative influences on TRM utilization. With a qualitative research approach involving rural and urban character, the study explored health beliefs and motivations for TRM use in Kumasi Metropolis and Sekyere South District, Ghana. The study draws on data from 36 in-depth interviews with adults, selected through theoretical sampling. We used the a posteriori inductive reduction model to derive broad themes and subthemes. The “pull factors”—perceived benefits in TRM use vis-à-vis the “push factors”—perceived poor services of the biomedical treatments contributed to the growing trends in TRM use. The result however indicates that the “pull factors,” viz.—personal health beliefs, desire to take control of one's health, perceived efficacy, and safety of various modalities of TRM—were stronger in shaping TRM use. Poor access to conventional medicine accounted for the differences in TRM use between rural and urban areas. Understanding the treatment and health-seeking behaviour of a cultural-related group is critical for developing and sustaining traditional therapy in Ghana. PMID:27018431

  8. Cooking fuels and the push for cleaner alternatives: a case study from Burkina Faso

    PubMed Central

    Yamamoto, Shelby; Sié, Ali; Sauerborn, Rainer

    2009-01-01

    Introduction More than 95% of the population in Burkina Faso uses some form of solid biomass fuel. When these fuels are burned in traditional, inefficient stoves, pollutant levels within and outside the home can be very high. This can have important consequences for both health and climate change. Thus, the push to switch to cleaner burning fuels is advantageous. However, there are several considerations that need to be taken into account when considering the use and promotion of different fuel types. Objective In the setting of the semi-urban area of Nouna, Burkina Faso, we examine the common fuel types used (wood, charcoal and liquid petroleum gas (LPG)) in terms of consumption, energy, availability, air pollution and climate change. Results and conclusion Although biomass solid fuel does offer some advantages over LPG, the disadvantages make this option much less desirable. Lower energy efficiencies, higher pollutant emission levels, the associated health consequences and climate change effects favour the choice of LPG over solid biomass fuel use. Further studies specific to Burkina Faso, which are lacking in this region, should also be undertaken in this area to better inform policy decisions. PMID:22778710

  9. Chemical Demilitarization Assembled Chemical Weapons Alternatives (Chem Demil-ACWA)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-243 Chemical Demilitarization-Assembled Chemical Weapons Alternatives (Chem Demil-ACWA) As...December 2015 SAR March 23, 2016 16:29:37 UNCLASSIFIED 2 Table of Contents Common Acronyms and Abbreviations for MDAP Programs 3 Program...Acquisition Unit Cost Chem Demil-ACWA December 2015 SAR March 23, 2016 16:29:37 UNCLASSIFIED 3 PB - President’s Budget PE - Program Element PEO - Program

  10. Pushed Out

    ERIC Educational Resources Information Center

    Brownstein, Rhonda

    2010-01-01

    Significant numbers of students are being pushed out of school as a result of "zero tolerance" school discipline policies. While nobody questions the need to keep schools safe, teachers, students, and parents are questioning the methods being used in pursuit of that goal. Zero tolerance policies were initially aimed at making schools safe. The…

  11. Pushed Out

    ERIC Educational Resources Information Center

    Brownstein, Rhonda

    2009-01-01

    Significant numbers of students are being pushed out of school as a result of "zero tolerance" school discipline policies. While nobody questions the need to keep schools safe, teachers, students, and parents are questioning the methods being used in pursuit of that goal. Initially enacted to counter violent behavior and drug use, zero tolerance…

  12. Analysis of alternative push-pull-test-designs for determining in-situ trapping of CO2

    NASA Astrophysics Data System (ADS)

    Rasmusson, M.; Rasmusson, K.; Fagerlund, F.; Niemi, A.; Bensabat, J.; Shtivelman, V.

    2012-04-01

    Modeling results of different single-well push-pull (injection-withdrawal) test designs have been analyzed for their ability to determine residual and dissolution trapping of CO2 in-situ. The modeling aims to improve the design of a CO2 push-pull test that will be part of the field experiment conducted at the Heletz site, Israel, within the EU FP7 MUSTANG project. The injection will take place in a saline formation, where the target layer, an about 10 m thick sandstone layer composed of three layers, is located at a depth of 1600 m. Single-well experiments complement two-well injection-monitoring tests in that they offer a way of reducing heterogeneity effects on CO2 transport in comparison to two-well tests. The test scenarios simulated combine thermal, hydraulic and tracer tests in line with the work by Zhang et al (2011), where the test sequences have three main stages divided into (i) reference tests, (ii) creation of a zone of residual gas saturation and (iii) testing during residual gas saturation conditions. One of the main interests is to compare different ways of creating the residual zone, the two principal approaches being to push the mobile CO2 away by injecting CO2 saturated water, thus leaving the residual zone behind or by pumping the mobile CO2 back. Implications of the different designs on optimal use of tracers are also analyzed. Inverse modeling with the iTOUGH2/EOS17 and EOS7c simulators is used to analyze the ability of the competing test designs to accurately determine parameters of main interest during CO2 sequestration, in particular the residual gas saturation and dissolution. The inverse modeling approach uses results from e.g. sensitivity analysis and uncertainty propagation analysis to make design decisions leading to improvements in the test scenarios, choosing the optimum pumping and injection rates, heating effects, amount of CO2 used, tracer and method to create the zone of residual CO2 trapping, leading to a test design that will

  13. Non-equilibrium self-assembly of ``sticky'' colloidal particles under alternating electric field

    NASA Astrophysics Data System (ADS)

    Snezhko, Alexey; Demortiere, Arnaud; Aranson, Igor

    2014-03-01

    Ensembles of interacting colloidal particles subject to an external periodic forcing often develop nontrivial self-assembled phases. We study emergent phenomena in partially cross-linked colloidal ensembles of epoxy particles driven out of equilibrium by alternating magnetic fields in a nonpolar solvent. We report on the discovery of self-assembled tunable networks of microscopic polymer fibers ranging from wavy colloidal ``fur'' to highly interconnected networks. The networks emerge via dynamic self-assembly in an alternating (ac) electric field from a non-aqueous suspension of ``sticky'' polymeric colloidal particles with a controlled degree of polymerization. The resulting architectures are tuned by the frequency and amplitude of the electric field and surface properties of the particles. The research was supported by the U.S. DOE, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under the Contract No. DE AC02-06CH11357

  14. A multimeric assembly factor controls the formation of alternative 20S proteasomes.

    PubMed

    Kusmierczyk, Andrew R; Kunjappu, Mary J; Funakoshi, Minoru; Hochstrasser, Mark

    2008-03-01

    The proteasome is the central regulatory protease of eukaryotic cells. Heteroheptameric alpha-subunit and beta-subunit rings stack to form the 20S proteasome, which associates with a 19S regulatory particle (RP). Here we show that two yeast proteins, Pba3 and Pba4, form a previously unidentified 20S proteasome-assembly chaperone. Pba3-Pba4 interacts genetically and physically with specific proteasomal alpha subunits, and loss of Pba3-Pba4 causes both a reduction and a remodeling of cellular proteasomes. Notably, mutant cells accumulate proteasomes in which a second copy of the alpha4 subunit replaces alpha3. 20S proteasome-assembly defects also are associated with altered RP assembly; this unexpected result suggests that the 20S proteasome can function as an RP-assembly factor in vivo. Our data demonstrate that Pba3-Pba4 orchestrates formation of a specific type of proteasome, the first example of a trans-acting factor that controls assembly of alternative proteasomal complexes.

  15. Alternate assembly sequence databook for the Tier 2 Bus-1 option of the International Space Station

    NASA Technical Reports Server (NTRS)

    Brewer, L. M.; Cirillo, W. M.; Cruz, J. N.; Hall, J. B.; Troutman, P. A.; Monell, D. W.; Garn, M. A.; Heck, M. L.; Kumar, R. R.; Llewellyn, C. P.

    1995-01-01

    The JSC International Space Station program office requested that SSB prepare a databook to document the alternate space station assembly sequence known as Tier 2, which assumes that the Russian participation has been eliminated and that the functions that were supplied by the Russians (propulsion, resupply, initial attitude control, communications, etc.) are now supplied by the U.S. Tier 2 utilizes the Lockheed Bus-l to replace much of the missing Russian functionality. The space station at each stage of its buildup during the Tier 2 assembly sequence is characterized in terms of of properties, functionality, resource balances, operations, logistics, attitude control, microgravity environment and propellant usage. The assembly sequence as analyzed was defined by JSC as a first iteration, with subsequent iterations required to address some of the issues that the analysis in this databook identified. Several significant issues were identified, including: less than desirable orbit lifetimes, shortage of EVA, large flight attitudes, poor microgravity environments, and reboost propellant shortages. Many of these issues can be resolved but at the cost of possible baseline modifications and revisions in the proposed Tier 2 assembly sequence.

  16. Alternate assembly sequence databook for the Tier 2 Bus-1 option of the International Space Station

    NASA Astrophysics Data System (ADS)

    Brewer, L. M.; Cirillo, W. M.; Cruz, J. N.; Hall, J. B.; Troutman, P. A.; Monell, D. W.; Garn, M. A.; Heck, M. L.; Kumar, R. R.; Llewellyn, C. P.

    1995-08-01

    The JSC International Space Station program office requested that SSB prepare a databook to document the alternate space station assembly sequence known as Tier 2, which assumes that the Russian participation has been eliminated and that the functions that were supplied by the Russians (propulsion, resupply, initial attitude control, communications, etc.) are now supplied by the U.S. Tier 2 utilizes the Lockheed Bus-l to replace much of the missing Russian functionality. The space station at each stage of its buildup during the Tier 2 assembly sequence is characterized in terms of of properties, functionality, resource balances, operations, logistics, attitude control, microgravity environment and propellant usage. The assembly sequence as analyzed was defined by JSC as a first iteration, with subsequent iterations required to address some of the issues that the analysis in this databook identified. Several significant issues were identified, including: less than desirable orbit lifetimes, shortage of EVA, large flight attitudes, poor microgravity environments, and reboost propellant shortages. Many of these issues can be resolved but at the cost of possible baseline modifications and revisions in the proposed Tier 2 assembly sequence.

  17. Packaging signals in single-stranded RNA viruses: nature's alternative to a purely electrostatic assembly mechanism.

    PubMed

    Stockley, Peter G; Twarock, Reidun; Bakker, Saskia E; Barker, Amy M; Borodavka, Alexander; Dykeman, Eric; Ford, Robert J; Pearson, Arwen R; Phillips, Simon E V; Ranson, Neil A; Tuma, Roman

    2013-03-01

    The formation of a protective protein container is an essential step in the life-cycle of most viruses. In the case of single-stranded (ss)RNA viruses, this step occurs in parallel with genome packaging in a co-assembly process. Previously, it had been thought that this process can be explained entirely by electrostatics. Inspired by recent single-molecule fluorescence experiments that recapitulate the RNA packaging specificity seen in vivo for two model viruses, we present an alternative theory, which recognizes the important cooperative roles played by RNA-coat protein interactions, at sites we have termed packaging signals. The hypothesis is that multiple copies of packaging signals, repeated according to capsid symmetry, aid formation of the required capsid protein conformers at defined positions, resulting in significantly enhanced assembly efficiency. The precise mechanistic roles of packaging signal interactions may vary between viruses, as we have demonstrated for MS2 and STNV. We quantify the impact of packaging signals on capsid assembly efficiency using a dodecahedral model system, showing that heterogeneous affinity distributions of packaging signals for capsid protein out-compete those of homogeneous affinities. These insights pave the way to a new anti-viral therapy, reducing capsid assembly efficiency by targeting of the vital roles of the packaging signals, and opens up new avenues for the efficient construction of protein nanocontainers in bionanotechnology.

  18. Self-Assembly of "Chalcone" Type Push-Pull Dye Molecules into Organic Single Crystalline Microribbons and Rigid Microrods for Vis/NIR Range Photonic Cavity Applications.

    PubMed

    Vattikunta, Radhika; Venkatakrishnarao, Dasari; Mohiddon, Mahamad Ahamad; Chandrasekar, Rajadurai

    2016-11-04

    A novel supramolecular fluorescent donor-acceptor type dye molecule, (2E,4E)-1-(2-hydroxyphenyl)-5-(pyren-1-yl)penta-2,4-dien-1-one (HPPD) self-assembles in a mixture of ethanol/chloroform through intermolecular π-π stacking (distance ca. 3.384 Å) to form J-aggregated single-crystalline microribbons displaying Fabry-Pèrot (F-P) type visible-range optical resonance. The corresponding borondifluoride dye (HPPD-BF), with a reduced HOMO-LUMO gap, self-assembles into crystalline microrods acting as an F-P type resonator in the near-infrared (NIR) range. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Human push capability.

    PubMed

    Barnett, Ralph L; Liber, Theodore

    2006-02-22

    Use of unassisted human push capability arises from time to time in the areas of crowd and animal control, the security of locked doors, the integrity of railings, the removal of tree stumps and entrenched vehicles, the manoeuvering of furniture, and athletic pursuits such as US football or wrestling. Depending on the scenario, human push capability involves strength, weight, weight distribution, push angle, footwear/floor friction, and the friction between the upper body and the pushed object. Simple models are used to establish the relationships among these factors.

  20. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  1. Tests of an alternate mobile transporter and extravehicular activity assembly procedure for the Space Station Freedom truss

    NASA Technical Reports Server (NTRS)

    Heard, Walter L., Jr.; Watson, Judith J.; Lake, Mark S.; Bush, Harold G.; Jensen, J. Kermit; Wallsom, Richard E.; Phelps, James E.

    1992-01-01

    Results are presented from a ground test program of an alternate mobile transporter (MT) concept and extravehicular activity (EVA) assembly procedure for the Space Station Freedom (SSF) truss keel. A three-bay orthogonal tetrahedral truss beam consisting of 44 2-in-diameter struts and 16 nodes was assembled repeatedly in neutral buoyancy by pairs of pressure-suited test subjects working from astronaut positioning devices (APD's) on the MT. The truss bays were cubic with edges 15 ft long. All the truss joint hardware was found to be EVA compatible. The average unit assembly time for a single pair of experienced test subjects was 27.6 sec/strut, which is about half the time derived from other SSF truss assembly tests. A concept for integration of utility trays during truss assembly is introduced and demonstrated in the assembly tests. The concept, which requires minimal EVA handling of the trays, is shown to have little impact on overall assembly time. The results of these tests indicate that by using an MT equipped with APD's, rapid EVA assembly of a space station-size truss structure can be expected.

  2. To push or not to push?

    PubMed

    Cruttenden, J

    1995-12-01

    Women in the second stage of labour instinctively bear down for short periods of four to six seconds. Most of these spontaneous bearing down efforts are accompanied by the release of air, with several breaths being taken between each effort. Conventional pushing techniques with sustained breath holding compromise fetal well being by reducing maternal arterial pressure and the oxygenation of maternal blood. Adequate progress may be made in labour, with the delivery of a healthy baby, when the management encourages spontaneous maternal efforts.

  3. Particle Engulfment and Pushing

    NASA Technical Reports Server (NTRS)

    2001-01-01

    As a liquefied metal solidifies, particles dispersed in the liquid are either pushed ahead of or engulfed by the moving solidification front. Similar effects can be seen when the ground freezes and pushes large particles out of the soil. The Particle Engulfment and Pushing (PEP) experiment, conducted aboard the fourth U.S. Microgravity Payload (USMP-4) mission in 1997, used a glass and plastic beads suspended in a transparent liquid. The liquid was then frozen, trapping or pushing the particles as the solidifying front moved. This simulated the formation of advanced alloys and composite materials. Such studies help scientists to understand how to improve the processes for making advanced materials on Earth. The principal investigator is Dr. Doru Stefanescu of the University of Alabama. This image is from a video downlink.

  4. Whether to push or pull? Nicotine reduction and non-combusted alternatives - Two strategies for reducing smoking and improving public health.

    PubMed

    Smith, Tracy T; Hatsukami, Dorothy K; Benowitz, Neal L; Colby, Suzanne M; McClernon, F Joseph; Strasser, Andrew A; Tidey, Jennifer W; White, Cassidy M; Donny, Eric C

    2018-03-29

    Combustible cigarettes remain the most harmful and addictive tobacco product, and reducing the prevalence of smoking continues to be a critical public health goal. While nicotine is the constituent primarily responsible for addiction to cigarettes, most of the harm associated with smoking comes from byproducts of tobacco combustion. Recently, two different approaches for reducing the harms of smoking have emerged, both of which focus on breaking the link between the addiction to nicotine and the harms caused by smoking. First, the addictive potential of cigarettes could be minimized by requiring a large reduction in the nicotine content of cigarettes. Evidence for a nicotine reduction policy thus far shows that the use of very low nicotine content cigarettes results in a reduction in the number of cigarettes people smoke per day and a reduction in cigarette dependence. Second, emerging alternative nicotine delivery systems (ANDS) like electronic cigarettes may provide sufficient nicotine to act as substitutes for cigarettes while delivering much lower levels of toxicants. Evidence suggests that the emergence of ANDS has increased the percentage of smokers who are able to quit. The present paper will briefly review the evidence for each of these approaches, and consider what contemporary reinforcement and addiction theories can tell us about their likely success. We argue that the most effective endgame approach is one that pursues both nicotine reduction and alternative nicotine delivery systems as complementary. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Push-Pull Locomotion for Vehicle Extrication

    NASA Technical Reports Server (NTRS)

    Creager, Colin M.; Johnson, Kyle A.; Plant, Mark; Moreland, Scott J.; Skonieczny, Krzysztof

    2014-01-01

    For applications in which unmanned vehicles must traverse unfamiliar terrain, there often exists the risk of vehicle entrapment. Typically, this risk can be reduced by using feedback from on-board sensors that assess the terrain. This work addressed the situations where a vehicle has already become immobilized or the desired route cannot be traversed using conventional rolling. Specifically, the focus was on using push-pull locomotion in high sinkage granular material. Push-pull locomotion is an alternative mode of travel that generates thrust through articulated motion, using vehicle components as anchors to push or pull against. It has been revealed through previous research that push-pull locomotion has the capacity for generating higher net traction forces than rolling, and a unique optical flow technique indicated that this is the result of a more efficient soil shearing method. It has now been found that pushpull locomotion results in less sinkage, lower travel reduction, and better power efficiency in high sinkage material as compared to rolling. Even when starting from an "entrapped" condition, push-pull locomotion was able to extricate the test vehicle. It is the authors' recommendation that push-pull locomotion be considered as a reliable back-up mode of travel for applications where terrain entrapment is a possibility.

  6. Push-pull betatron pair

    DOEpatents

    Kerst, Donald W.

    1986-01-01

    A push-pull betatron accelerator with two coaxial betatron tubes in which two electron beams are alternately accelerated in opposite directions of rotation. Both tubes are linked by the same alternating current accelerating flux produced by one or more accelerating flux coils. The betatron tubes are provided with guide fields having alternating current components which are in the same direction and having direct current biasing components which are in opposite directions. One electron beam is accelerated when the accelerating flux is changing between its negative maximum and its positive maximum, while the other beam is accelerated when the accelerating flux is changing between its positive maximum and its negative maximum. In another embodiment, there is only one betatron tube, in which two electron beams are alternately accelerated in opposite directions of rotation; and in still another embodiment, there are two tubes in which electrons are accelerated alternately, but the AC components for the guide fields are in opposite directions for the two tubes, while the DC biasing components are polarized the same for both tubes.

  7. Push type fastener

    NASA Astrophysics Data System (ADS)

    Jackson, Steven A.

    1994-11-01

    A push type fastener for fastening a movable structural part (41) to a fixed structural part (43), wherein the coupling and decoupling actions are both a push type operation, the fastener consisting of a plunger (12) having a shank (20) with a plunger head (18) at one end and a threaded end portion (26a) at the other end, an expandable grommet (14) adapted to receive the plunger shank (20) therethrough, and an attachable head (16) which is securable to the threaded end of the plunger shank (20). The fastener (10) requires each structural part (41, 43) to be provided with an aperture (45, 46) and the attachable head (16) to be smaller than the aperture (46) in the second structural part. The plunger (12) is extensible through the grommet (14) and is structurally configured with an external camming surface (25) which is cooperatively engageable with internal surfaces (38) of the grommet so that when the plunger is inserted in the grommet, the relative positioning of said cooperable camming surfaces determines the expansion of the grommet. Coupling of the parts is effected when the grommet is inserted in the aperture (46) in the fixed structural part (43) and expanded by pushing the plunger head (18) and plunger at least a minimal distance through the grommet. Decoupling is effected by pushing the attachable head (16).

  8. Push type fastener

    NASA Technical Reports Server (NTRS)

    Jackson, Steven A. (Inventor)

    1994-01-01

    A push type fastener for fastening a movable structural part (41) to a fixed structural part (43), wherein the coupling and decoupling actions are both a push type operation, the fastener consisting of a plunger (12) having a shank (20) with a plunger head (18) at one end and a threaded end portion (26a) at the other end, an expandable grommet (14) adapted to receive the plunger shank (20) therethrough, and an attachable head (16) which is securable to the threaded end of the plunger shank (20). The fastener (10) requires each structural part (41, 43) to be provided with an aperture (45, 46) and the attachable head (16) to be smaller than the aperture (46) in the second structural part. The plunger (12) is extensible through the grommet (14) and is structurally configured with an external camming surface (25) which is cooperatively engageable with internal surfaces (38) of the grommet so that when the plunger is inserted in the grommet, the relative positioning of said cooperable camming surfaces determines the expansion of the grommet. Coupling of the parts is effected when the grommet is inserted in the aperture (46) in the fixed structural part (43) and expanded by pushing the plunger head (18) and plunger at least a minimal distance through the grommet. Decoupling is effected by pushing the attachable head (16).

  9. Stochastic Assembly Leads to Alternative Communities with Distinct Functions in a Bioreactor Microbial Community

    PubMed Central

    Zhou, Jizhong; Liu, Wenzong; Deng, Ye; Jiang, Yi-Huei; Xue, Kai; He, Zhili; Van Nostrand, Joy D.; Wu, Liyou; Yang, Yunfeng; Wang, Aijie

    2013-01-01

    ABSTRACT The processes and mechanisms of community assembly and its relationships to community functioning are central issues in ecology. Both deterministic and stochastic factors play important roles in shaping community composition and structure, but the connection between community assembly and ecosystem functioning remains elusive, especially in microbial communities. Here, we used microbial electrolysis cell reactors as a model system to examine the roles of stochastic assembly in determining microbial community structure and functions. Under identical environmental conditions with the same source community, ecological drift (i.e., initial stochastic colonization) and subsequent biotic interactions created dramatically different communities with little overlap among 14 identical reactors, indicating that stochastic assembly played dominant roles in determining microbial community structure. Neutral community modeling analysis revealed that deterministic factors also played significant roles in shaping microbial community structure in these reactors. Most importantly, the newly formed communities differed substantially in community functions (e.g., H2 production), which showed strong linkages to community structure. This study is the first to demonstrate that stochastic assembly plays a dominant role in determining not only community structure but also ecosystem functions. Elucidating the links among community assembly, biodiversity, and ecosystem functioning is critical to understanding ecosystem functioning, biodiversity preservation, and ecosystem management. PMID:23462114

  10. Push-pull betatron pair

    DOEpatents

    Kerst, D.W.

    1984-02-22

    The disclosed push-pull betatron accelerator has first and second coaxial betatron tubes in which first and second electron beams are alternately accelerated in opposite directions of rotation. Both tubes are linked by the same alternating current accelerating flux, produced by one or more accelerating flux coils. The betatron tubes are provided with first and second guide fields having alternating current components which are in the same direction. The first and second guide fields have direct current biasing components which are in opposite directions for the two betatron tubes. In this way, the full advantages of guide field biasing are achieved. The first electron beam is accelerated in the first tube when the accelerating flux is changing between its negative maximum and its positive maximum values. The second electron beam is accelerated in the second tube when the accelerating flux is changing between its positive maximum value and its negative maximum value. In another embodiment, there is only one betatron tube, in which two electron beams are alternately accelerated in opposite directions of rotation.

  11. Alternatives to the conference status quo: summary recommendations from the 2008 CORD Academic Assembly Conference Alternatives workgroup.

    PubMed

    Sadosty, Annie T; Goyal, Deepi G; Gene Hern, H; Kilian, Barbara J; Beeson, Michael S

    2009-12-01

    Abstract Objective: A panel of Council of Emergency Medicine Residency Directors (CORD) members was asked to examine and make recommendations regarding the existing Accreditation Council of Graduate Medical Education (ACGME) EM Program Requirements pertaining to educational conferences, identified best practices, and recommended revisions as appropriate. Using quasi-Delphi technique, 30 emergency medicine (EM) residency program directors and faculty examined existing requirements. Findings were presented to the CORD members attending the 2008 CORD Academic Assembly, and disseminated to the broader membership through the CORD e-mail list server. The following four ACGME EM Program Requirements were examined, and recommendations made: 1. The 5 hours/week conference requirement: For fully accredited programs in good standing, outcomes should be driving how programs allocate and mandate educational time. Maintain the 5 hours/week conference requirement for new programs, programs with provisional accreditation, programs in difficult political environs, and those with short accreditation cycles. If the program requirements must retain a minimum hours/week reference, future requirements should take into account varying program lengths (3 versus 4 years). 2. The 70% attendance requirement: Develop a new requirement that allows programs more flexibility to customize according to local resources, individual residency needs, and individual resident needs. 3. The requirement for synchronous versus asynchronous learning: Synchronous and asynchronous learning activities have advantages and disadvantages. The ideal curriculum capitalizes on the strengths of each through a deliberate mixture of each. 4. Educationally justified innovations: Transition from process-based program requirements to outcomes-based requirements. The conference requirements that were logical and helpful years ago may not be logical or helpful now. Technologies available to educators have changed, the

  12. Self-assembly of metal nanowires induced by alternating current electric fields

    NASA Astrophysics Data System (ADS)

    García-Sánchez, Pablo; Arcenegui, Juan J.; Morgan, Hywel; Ramos, Antonio

    2015-01-01

    We describe the reversible assembly of an aqueous suspension of metal nanowires into two different 2-dimensional stable configurations. The assembly is induced by an AC electric field of magnitude around 10 kV/m. It is known that single metal nanowires orientate parallel to the electric field for all values of applied frequency, according to two different mechanisms depending on the frequency. These different mechanisms also govern the mutual interaction between nanowires, which leads to directed-assembly into distinctive structures, the shape of which depends on the frequency of the applied field. We show that for frequencies higher than the typical frequency for charging the electrical double layer at the metal-electrolyte interface, dipole-dipole interaction leads to the formation of chains of nanowires. For lower frequencies, the nanowires form wavy bands perpendicular to the electric field direction. This behavior appears to be driven by the electroosmotic flow induced on the metal surface of the nanowires. Remarkably, no similar structures have been reported in previous studies of nanowires.

  13. Wireline system for multiple direct push tool usage

    DOEpatents

    Bratton, Wesley L.; Farrington, Stephen P.; Shinn, II, James D.; Nolet, Darren C.

    2003-11-11

    A tool latching and retrieval system allows the deployment and retrieval of a variety of direct push subsurface characterization tools through an embedded rod string during a single penetration without requiring withdrawal of the string from the ground. This enables the in situ interchange of different tools, as well as the rapid retrieval of soil core samples from multiple depths during a single direct push penetration. The system includes specialized rods that make up the rod string, a tool housing which is integral to the rod string, a lock assembly, and several tools which mate to the lock assembly.

  14. Plasma Push and Pull

    NASA Image and Video Library

    2015-07-08

    Dark strands of plasma hovering above the sun's surface began to interact with each other in a form of tug of war over two and a half days on June 28-30, 2015. At times, strands of plasma extended a tenuous connection between one area and the other. Twice the small tower of plasma to the lower left shot a burst of energy over to the quivering filament higher up. We are seeing the push and pull of magnetic forces revealed in a 193 wavelength of extreme ultraviolet light, typically colorized in brown. Credit: NASA/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  15. Directional, stabilizing, and disruptive trait selection as alternative mechanisms for plant community assembly.

    PubMed

    Rolhauser, Andrés G; Pucheta, Eduardo

    2017-03-01

    suggest that abiotic stress may drive within-community functional convergence independently of the trait considered, opposing the view that some traits may be inherently convergent while others divergent. Our quadratic model-based approach provides standardized metrics of both linear and nonlinear selection that may allow simple comparisons among communities subjected to contrasting environmental conditions. These concepts, rooted in natural selection theory, may clarify the functional link between traits and species abundance, and thus help untangle the contributions of deterministic and stochastic processes on community assembly. © 2017 by the Ecological Society of America.

  16. Extremely bright full color alternating current electroluminescence of solution-blended fluorescent polymers with self-assembled block copolymer micelles.

    PubMed

    Cho, Sung Hwan; Jo, Seong Soon; Hwang, Ihn; Sung, Jinwoo; Seo, Jungmok; Jung, Seok-Heon; Bae, Insung; Choi, Jae Ryung; Cho, Himchan; Lee, Taeyoon; Lee, Jin Kyun; Lee, Tae-Woo; Park, Cheolmin

    2013-12-23

    Electroluminescent (EL) devices operating at alternating current (AC) electricity have been of great interest due to not only their unique light emitting mechanism of carrier generation and recombination but also their great potential for applications in displays, sensors, and lighting. Despite great success of AC-EL devices, most device properties are far from real implementation. In particular, the current state-of-the art brightness of the solution-processed AC-EL devices is a few hundred candela per square meter (cd m(-2)) and most of the works have been devoted to red and white emission. In this manuscript, we report extremely bright full color polymer AC-EL devices with brightness of approximately 2300, 6000, and 5000 cd m(-2) for blue (B), green (G), and red (R) emission, respectively. The high brightness of blue emission was attributed to individually networked multiwalled carbon nanotubes (MWNTs) for the facile carrier injection as well as self-assembled block copolymer micelles for suppression of interchain nonradiative energy quenching. In addition, effective FRET from a solution-blended thin film of B-G and B-G-R fluorescent polymers led to very bright green and red EL under AC voltage, respectively. The solution-processed AC-EL device also worked properly with vacuum-free Ag paste on a mechanically flexible polymer substrate. Finally, we successfully demonstrated the long-term operation reliability of our AC-EL device for over 15 h.

  17. Push-pull farming systems.

    PubMed

    Pickett, John A; Woodcock, Christine M; Midega, Charles A O; Khan, Zeyaur R

    2014-04-01

    Farming systems for pest control, based on the stimulo-deterrent diversionary strategy or push-pull system, have become an important target for sustainable intensification of food production. A prominent example is push-pull developed in sub-Saharan Africa using a combination of companion plants delivering semiochemicals, as plant secondary metabolites, for smallholder farming cereal production, initially against lepidopterous stem borers. Opportunities are being developed for other regions and farming ecosystems. New semiochemical tools and delivery systems, including GM, are being incorporated to exploit further opportunities for mainstream arable farming systems. By delivering the push and pull effects as secondary metabolites, for example, (E)-4,8-dimethyl-1,3,7-nonatriene repelling pests and attracting beneficial insects, problems of high volatility and instability are overcome and compounds are produced when and where required. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Book Review: Sapphire. (1996). Push.

    ERIC Educational Resources Information Center

    Hayes, Elisabeth; Cuban, Sondra

    1998-01-01

    This review of "Push," a novel about a young single mother in a literacy education program, incorporates theoretical elements from Allan Quigley's "Rethinking Literacy Education." The review addresses issues of stereotypes, humanistic education, and advocacy and includes reflections on teaching philosophy in adult basic…

  19. Illuminated push-button switch

    NASA Technical Reports Server (NTRS)

    Iwagiri, T.

    1983-01-01

    An illuminated push-button switch is described. It is characterized by the fact that is consists of a switch group, an operator button opening and closing the switch group, and a light-emitting element which illuminates the face of the operator button.

  20. Renewed Push on ESEA Likely

    ERIC Educational Resources Information Center

    Klein, Alyson

    2011-01-01

    A prominent and sustained White House push for renewal of the Elementary and Secondary Education Act (ESEA) is viewed as crucial to prospects for the 9-year-old law's reauthorization by a now-divided Congress. The law's current version, the No Child Left Behind Act, was President George W. Bush's signature domestic achievement when it was passed…

  1. Sample push-out fixture

    DOEpatents

    Biernat, John L.

    2002-11-05

    This invention generally relates to the remote removal of pelletized samples from cylindrical containment capsules. V-blocks are used to receive the samples and provide guidance to push out rods. Stainless steel liners fit into the v-channels on the v-blocks which permits them to be remotely removed and replaced or cleaned to prevent cross contamination between capsules and samples. A capsule holder securely holds the capsule while allowing manual up/down and in/out movement to align each sample hole with the v-blocks. Both end sections contain identical v-blocks; one that guides the drive out screw and rods or manual push out rods and the other to receive the samples as they are driven out of the capsule.

  2. Push-pull quinoidal porphyrins.

    PubMed

    Smith, Martin J; Blake, Iain M; Clegg, William; Anderson, Harry L

    2018-05-01

    A family of push-pull quinoidal porphyrin monomers has been prepared from a meso-formyl porphyrin by bromination, thioacetal formation, palladium-catalyzed coupling with malononitrile and oxidation with DDQ. Attempts at extending this synthesis to a push-pull quinoidal/cumulenic porphyrin dimer were not successful. The crystal structures of the quinoidal porphyrins indicate that there is no significant contribution from singlet biradical or zwitterionic resonance forms. The crystal structure of an ethyne-linked porphyrin dimer shows that the torsion angle between the porphyrin units is only about 3°, in keeping with crystallographic results on related compounds, but contrasting with the torsion angle of about 35° predicted by computational studies. The free-base quinoidal porphyrin monomers form tightly π-stacked layer structures, despite their curved geometries and bulky aryl substituents.

  3. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven...

  4. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power...

  5. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... pushed: Composite unit. 90.3 Section 90.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power...

  6. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... pushed: Composite unit. 82.3 Section 82.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven...

  7. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pushed: Composite unit. 82.3 Section 82.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven...

  8. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... pushed: Composite unit. 82.3 Section 82.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven...

  9. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pushed: Composite unit. 90.3 Section 90.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power...

  10. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pushed: Composite unit. 90.3 Section 90.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power...

  11. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... pushed: Composite unit. 90.3 Section 90.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power...

  12. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pushed: Composite unit. 82.3 Section 82.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they are regarded as a power-driven...

  13. Measuring the length distribution of self-assembled lipid nanotubes by orientation control with a high-frequency alternating current electric field in aqueous solutions.

    PubMed

    Hirano, Ken; Aoyagi, Masaru; Ishido, Tomomi; Ooie, Toshihiko; Frusawa, Hiroshi; Asakawa, Masumi; Shimizu, Toshimi; Ishikawa, Mitsuru

    2009-02-15

    The present work addresses the length distribution of self-assembled lipid nanotubes (LNTs) by controlling the orientation of the LNTs using an alternating current (ac) electric field in aqueous solutions. The effect of the ac field on the orientation and rotation of individual LNTs was examined to evaluate the optimum orientation frequency by visualizing the individual LNTs in real time. By using the high-frequency ac field, we have successfully measured the length distribution for two different types of LNTs and have quantitatively analyzed the maximum occurrences of the length distribution as well as the extension of the longer length region.

  14. An Alternative Model for the Role of RP2 Protein in Flagellum Assembly in the African Trypanosome*

    PubMed Central

    Andre, Jane; Kerry, Louise; Qi, Xin; Hawkins, Erica; Drižytė, Kristina; Ginger, Michael L.; McKean, Paul G.

    2014-01-01

    The tubulin cofactor C domain-containing protein TbRP2 is a basal body (centriolar) protein essential for axoneme formation in the flagellate protist Trypanosoma brucei, the causal agent of African sleeping sickness. Here, we show how TbRP2 is targeted and tethered at mature basal bodies and provide novel insight into TbRP2 function. Regarding targeting, understanding how several hundred proteins combine to build a microtubule axoneme is a fundamental challenge in eukaryotic cell biology. We show that basal body localization of TbRP2 is mediated by twinned, N-terminal TOF (TON1, OFD1, and FOP) and LisH motifs, motifs that otherwise facilitate localization of only a few conserved proteins at microtubule-organizing centers in animals, plants, and flagellate protists. Regarding TbRP2 function, there is a debate as to whether the flagellar assembly function of specialized, centriolar tubulin cofactor C domain-containing proteins is processing tubulin, the major component of axonemes, or general vesicular trafficking in a flagellum assembly context. Here we report that TbRP2 is required for the recruitment of T. brucei orthologs of MKS1 and MKS6, proteins that, in animal cells, are part of a complex that assembles at the base of the flagellum to regulate protein composition and cilium function. We also identify that TbRP2 is detected by YL1/2, an antibody classically used to detect α-tubulin. Together, these data suggest a general processing role for TbRP2 in trypanosome flagellum assembly and challenge the notion that TbRP2 functions solely in assessing tubulin “quality” prior to tubulin incorporation into the elongating axoneme. PMID:24257747

  15. Distinct Adsorption Configurations and Self-Assembly Characteristics of Fibrinogen on Chemically Uniform and Alternating Surfaces including Block Copolymer Nanodomains

    PubMed Central

    2015-01-01

    Understanding protein–surface interactions is crucial to solid-state biomedical applications whose functionality is directly correlated with the precise control of the adsorption configuration, surface packing, loading density, and bioactivity of protein molecules. Because of the small dimensions and highly amphiphilic nature of proteins, investigation of protein adsorption performed on nanoscale topology can shed light on subprotein-level interaction preferences. In this study, we examine the adsorption and assembly behavior of a highly elongated protein, fibrinogen, on both chemically uniform (as-is and buffered HF-treated SiO2/Si, and homopolymers of polystyrene and poly(methyl methacrylate)) and varying (polystyrene-block-poly(methyl methacrylate)) surfaces. By focusing on high-resolution imaging of individual protein molecules whose configurations are influenced by protein–surface rather than protein–protein interactions, fibrinogen conformations characteristic to each surface are identified and statistically analyzed for structural similarities/differences in key protein domains. By exploiting block copolymer nanodomains whose repeat distance is commensurate with the length of the individual protein, we determine that fibrinogen exhibits a more neutral tendency for interaction with both polystyrene and poly(methyl methacrylate) blocks relative to the case of common globular proteins. Factors affecting fibrinogen–polymer interactions are discussed in terms of hydrophobic and electrostatic interactions. In addition, assembly and packing attributes of fibrinogen are determined at different loading conditions. Primary orientations of fibrinogen and its rearrangements with respect to the underlying diblock nanodomains associated with different surface coverage are explained by pertinent protein interaction mechanisms. On the basis of two-dimensional stacking behavior, a protein assembly model is proposed for the formation of an extended fibrinogen network

  16. Pushing and pulling, technique and load effects: an electromyographical study.

    PubMed

    Bennett, A I; Todd, A I; Desai, S D

    2011-01-01

    Increasing awareness of the high physical cost associated with lifting has led to the redesign of these tasks, incorporating manual handling devices and consequently pushing and pulling. Little research has focused on muscle activity responses to pushing and pulling, the current study therefore investigated these responses to further the understanding of risk of injury, informing ergonomics intervention strategies. A laboratory study was undertaken to determine the effect of three push/pull techniques and two loads (250 and 500 kg) on muscle activation in nine muscles, distributed through the upper and lower body. Unloaded forward and backward walking were used as control conditions for lower limb muscle activation. Thirty-six healthy male volunteers participated in the study. Subjects were required to manoeuvre a loaded pallet jack at a velocity of 0.45-0.55 statures. The muscles of the shoulders and upper extremity were affected to a greater degree by technique and load changes than those of the lower limbs. Further, high levels of erector spinae activation were recorded across all six experimental conditions. Each technique displayed a unique muscle activation profile, indicating that alternating between techniques may reduce early onset of fatigue. Further understanding of muscle activation during pushing and pulling is necessary.

  17. Synthesizing a novel genetic sequential logic circuit: a push-on push-off switch

    PubMed Central

    Lou, Chunbo; Liu, Xili; Ni, Ming; Huang, Yiqi; Huang, Qiushi; Huang, Longwen; Jiang, Lingli; Lu, Dan; Wang, Mingcong; Liu, Chang; Chen, Daizhuo; Chen, Chongyi; Chen, Xiaoyue; Yang, Le; Ma, Haisu; Chen, Jianguo; Ouyang, Qi

    2010-01-01

    Design and synthesis of basic functional circuits are the fundamental tasks of synthetic biologists. Before it is possible to engineer higher-order genetic networks that can perform complex functions, a toolkit of basic devices must be developed. Among those devices, sequential logic circuits are expected to be the foundation of the genetic information-processing systems. In this study, we report the design and construction of a genetic sequential logic circuit in Escherichia coli. It can generate different outputs in response to the same input signal on the basis of its internal state, and ‘memorize' the output. The circuit is composed of two parts: (1) a bistable switch memory module and (2) a double-repressed promoter NOR gate module. The two modules were individually rationally designed, and they were coupled together by fine-tuning the interconnecting parts through directed evolution. After fine-tuning, the circuit could be repeatedly, alternatively triggered by the same input signal; it functions as a push-on push-off switch. PMID:20212522

  18. Size-exclusion HPLC provides a simple, rapid, and versatile alternative method for quality control of vaccines by characterizing the assembly of antigens.

    PubMed

    Yang, Yanli; Li, Hao; Li, Zhengjun; Zhang, Yan; Zhang, Songping; Chen, Yi; Yu, Mengran; Ma, Guanghui; Su, Zhiguo

    2015-02-25

    The assembly of antigen structure is often crucial to the potency of vaccines. Currently adopted methods like animal testing and ultracentrifugation take long time and are difficult to automate for multiple samples. Here we develop a size-exclusion high-performance liquid chromatography (SE-HPLC) method to characterize the assembly of antigen structure during both manufacturing process and storage. Three important vaccine antigens including inactivated foot and mouth disease virus (FMDV), which is a virus vaccine; and two virus-like particles (VLPs) vaccines involving hepatitis B core antigen (HBcAg) VLPs, and hepatitis B surface antigen (HBsAg) VLPs, were successfully analyzed using commercially available TSK gel columns with pore size above 45nm. Combined with other analytical methods including SDS-PAGE, dynamic light scattering, wavelength scan, and multi-angle laser light scattering, the SE-HPLC method was proven to be a simple, rapid, and reliable tool for antigen particles assembly analysis. Specifically, for FMDV whole virus particle, SE-HPLC was used to analyze 146S content in vaccine preparations and the thermal dissociation of the 146S. For HBcAg-VLPs that are expressed in recombinant Escherichia coli, its expression level during cell culture process was quantitatively monitored by SE-HPLC. The SE-HPLC also showed applicability for quality check of HBsAg vaccine preparations by monitoring the product consistency of different lot number and the product stability during storage. Results shown in this work clearly demonstrated that SE-HPLC method has potential as a versatile alternative technology for control of the final product by both manufacturers and the regulatory agencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Supporting women's instinctive pushing behaviour during birth.

    PubMed

    2015-06-01

    During birth women instinctively push in the most effective and safe way for themselves and their babies. However, midwives continue to direct women's pushing behaviours. The assumptions underpinning this practice must be examined and challenged. Midwives need to develop an evidence-based approach that acknowledges and reinforces women's innate ability to birth.

  20. Towards electrochromic devices having visible color switching using electronic push-push and push-pull cinnamaldehyde derivatives.

    PubMed

    Navarathne, Daminda; Skene, W G

    2013-12-11

    A series of symmetric and unsymmetric conjugated azomethines derived from cinnamaldehyde and 2,5-diaminothiophene-3,4-dicarboxylic acid diethyl ester were prepared. The optical, electrochemical, and spectroelectrochemical properties of the electronic push-pull and push-push triads were investigated. Their properties could be tuned contingent on the cinnamaldehyde's electron withdrawing and donating substituents. The push-push symmetric derivative exhibited positive solvatochromism with the absorbance spanning some 31 nm, depending on the solvent polarity. Solvent dependent spectroelectrochemistry was also found for the symmetric push-push azomethine. The color of the neutral state and radical cation spanned 215 nm. The most pronounced color transition of the purple colored material was found in dimethyl sulfoxide (DMSO), where the color bleached with electrochemical oxidation. This was a result of the absorbance shifting into the near infrared (NIR) and not from decomposition of the azomethine. Electrochromic devices with the azomethines possessing desired reversible oxidation and color changes in the visible were fabricated and tested to demonstrate the applicability of these azomethine triads in devices.

  1. PUSHing core-collapse simulations to explosion

    NASA Astrophysics Data System (ADS)

    Fröhlich, C.; Perego, A.; Hempe, M.; Ebinger, K.; Eichler, M.; Casanova, J.; Liebendörfer, M.; Thielemann, F.-K.

    2018-01-01

    We report on the PUSH method for artificially triggering core-collapse supernova explosions of massive stars in spherical symmetry. The PUSH method increases the energy deposition in the gain region proportionally to the heavy flavor neutrino fluxes.We summarize the parameter dependence of the method and calibrate PUSH to reproduce SN 1987A observables. We identify a best-fit progenitor and set of parameters that fit the explosion properties of SN 1987A, assuming 0.1 M⊙ of fallback. For the explored progenitor range of 18-21 M⊙, we find correlations between explosion properties and the compactness of the progenitor model.

  2. The back compressive forces during maximal push-pull activities in the sagittal plane.

    PubMed

    Kumar, S

    1994-12-01

    Ten normal young male and ten normal young female subjects (each group with a mean age of 21.1 years) performed isometric and isokinetic (50 cm per second) push and pull activity at 35 cm, 100 cm and 150 cm heights. The subjects were placed on a specially designed subject-stabilizing-platform to stabilize their lower extremities. Horizontal push-pull forces were exerted through a friction-reduced rod and sleeve assembly attached to the modified Static Dynamic Strength Tester. The strength measured by a SM 500 load cell was fed to an IBM XT through an A to D converter. The postural records were made on a videotape. The posture and strength were synchronized through an external light signal. The strength for pull activities was higher than the corresponding push activities (p < 0.01). The isometric strengths were significantly higher than the isokinetic strengths (p < 0.01). Though the push strengths were significantly lower than the pull strength, the low-back compressive forces for the push activities were 129% to 627% of the corresponding pull conditions. It is concluded that the push activities are more hazardous due to the higher magnitude of compressive load and their faster contribution to the threshold level of cumulative load leading to the precipitation of injuries.

  3. Insights into the Effects of Complement Factor H on the Assembly and Decay of the Alternative Pathway C3 Proconvertase and C3 Convertase.

    PubMed

    Bettoni, Serena; Bresin, Elena; Remuzzi, Giuseppe; Noris, Marina; Donadelli, Roberta

    2016-04-08

    The activated fragment of C3 (C3b) and factor B form the C3 proconvertase (C3bB), which is cleaved by factor D to C3 convertase (C3bBb). Older studies (Conrad, D. H., Carlo, J. R., and Ruddy, S. (1978)J. Exp. Med.147, 1792-1805; Pangburn, M. K., and Müller-Eberhard, H. J. (1978)Proc. Natl. Acad. Sci. U.S.A.75, 2416-2420; Kazatchkine, M. D., Fearon, D. T., and Austen, K. F. (1979)J. Immunol.122, 75-81) indicated that the complement alternative pathway regulator factor H (FH) competes with factor B for C3b binding; however, the capability of FH to prevent C3bB assembly has not been formally investigated. Moreover, in the few published studies FH did not favor C3bB dissociation. Whether FH may affect C3bBb formation from C3bB is unknown. We set up user-friendly assays based on combined microplate/Western blotting techniques that specifically detect either C3bB or C3bBb, with the aim of investigating the effect of FH on C3bB assembly and decay and C3bBb formation and decay. We document that FH does not affect C3bB assembly, indicating that FH does not efficiently compete with factor B for C3b binding. We also found that FH does not dissociate C3bB. FH showed a strong C3bBb decay-accelerating activity, as reported previously, and also exerted an apparent inhibitory effect on C3bBb formation. The latter effect was not fully attributable to a rapid FH-mediated dissociation of C3bBb complexes, because blocking decay with properdin and C3 nephritic factor did not restore C3bBb formation. FH almost completely prevented release of the smaller cleavage subunit of FB (Ba), without modifying the amount of C3bB complexes, suggesting that FH inhibits the conversion of C3bB to C3bBb. Thus, the inhibitory effect of FH on C3bBb formation is likely the sum of inhibition of C3bB conversion to C3bBb and of C3bBb decay acceleration. Further studies are required to confirm these findings in physiological cell-based settings. © 2016 by The American Society for Biochemistry and Molecular

  4. Demonstration of low flow push-pull perfusion.

    PubMed

    Kottegoda, Sumith; Shaik, Imtiazuddin; Shippy, Scott A

    2002-11-15

    Methods to follow in vivo chemical composition provide information regarding the processes of intercellular communication. There is a need for methods that provide chemical information from small volumes of the central nervous system (CNS) without sacrificing neurochemical recovery. One method that offers potential for providing such information is push-pull perfusion. In this study a low flow push-pull perfusion system is introduced that provides high (70-80%) in vitro recoveries. A concentric probe design is used with a 27-gauge stainless steel outer cannula for saline infusion and an inner fused silica capillary for fluid withdrawal. Flow rates of 10-50 nl/min were reliably generated and were well matched in vitro. Sampling was performed in the striatum of an anesthetized rat generating a 0.5 microl sample every 12 min. Capillary electrophoresis was used to determine glutamate levels in each sample; the basal level was found to be 1.97+/-0.70 microM. The method described was also demonstrated to deliver L-trans-pyrrolidine-2,4-dicarboxylic acid through the perfusion solution while sampling. Post-sampling histological analysis demonstrates little tissue disturbance to the sampled region. These data provide evidence that low flow push-pull method is a viable alternative for studying neurochemical signaling in the CNS.

  5. Hybrid self-assembled multilayer film formed by alternating layers of H{sub 4}SiW{sub 12}O{sub 40} and 1,10-diaminodecane (DAD)

    SciTech Connect

    Wang Kezhi; Gao Lihua

    2002-12-01

    A hybrid self-assembled multilayer film was prepared by alternating adsorption of H{sub 4}SiW{sub 12}O{sub 40} and 1,10-diaminodecane. The film was uniformly deposited and was found to be photochromic, as monitored by the UV spectroscopy. The film was also studied by X-ray photoelectron spectroscopy.

  6. The NASA technology push towards future space mission systems

    NASA Technical Reports Server (NTRS)

    Sadin, Stanley R.; Povinelli, Frederick P.; Rosen, Robert

    1988-01-01

    As a result of the new Space Policy, the NASA technology program has been called upon to a provide a solid base of national capabilities and talent to serve NASA's civil space program, commercial, and other space sector interests. This paper describes the new technology program structure and its characteristics, traces its origin and evolution, and projects the likely near- and far-term strategic steps. It addresses the alternative 'push-pull' approaches to technology development, the readiness levels to which the technology needs to be developed for effective technology transfer, and the focused technology programs currently being implemented to satisfy the needs of future space systems.

  7. Hydraulic tests with direct-push equipment

    USGS Publications Warehouse

    Butler, J.J.; Healey, J.M.; McCall, G.W.; Garnett, E.J.; Loheide, Steven P.

    2002-01-01

    The potential of direct-push technology for hydraulic characterization of saturated flow systems was investigated at a field site with a considerable degree of subsurface control. Direct-push installations were emplaced by attaching short lengths of screen (shielded and unshielded) to the bottom end of a tool string that was then advanced into the unconsolidated sediments. A series of constant-rate pumping tests were performed in a coarse sand and gravel aquifer using direct-push tool strings as observation wells. Very good agreement (within 4%) was found between hydraulic conductivity (K) estimates from direct-push installations and those from conventional wells. A program of slug tests was performed in direct-push installations using small-diameter adaptations of solid-slug and pneumatic methods. In a sandy silt interval of moderate hydraulic conductivity, K values from tests in a shielded screen tool were in excellent agreement (within 2%) with those from tests in a nearby well. In the coarse sand and gravel aquifer, K values were within 12% of those from multilevel slug tests at a nearby well. However, in the more permeable portions of the aquifer (K > 70 m/day), the smaller-diameter direct-push rods (0.016 m inner diameter [I.D.]) attenuated test responses, leading to an underprediction of K. In those conditions, use of larger-diameter rods (e.g., 0.038 m I.D.) is necessary to obtain K values representative of the formation. This investigation demonstrates that much valuable information can be obtained from hydraulic tests in direct-push installations. As with any type of hydraulic test, K estimates are critically dependent on use of appropriate emplacement and development procedures. In particular, driving an unshielded screen through a heterogeneous sequence will often lead to a buildup of low-K material that can be difficult to remove with standard development procedures.

  8. The Push Is On: What Push Technology Means to the Librarian.

    ERIC Educational Resources Information Center

    Gustitus, Cheryl

    1998-01-01

    "Push technology," or Webcasting, employs user defined criteria to search for specific information and deliver it when and where directed, enhancing the value special librarians add to the information dissemination process. This article examines push technology, its Internet and Intranet applications, and commercially available…

  9. PUSH-PULL POWER REACTOR

    DOEpatents

    Froman, D.K.

    1959-02-24

    Power generating nuclear reactors of the homogeneous liquid fuel type are discussed. The apparatus utilizes two identical reactors interconnected by conduits through heat exchanging apparatus. Each reactor contains a critical geometry region and a vapor region separated from the critical region by a baffle. When the liquid in the first critical region becomes critical, the vapor pressure above the fuel is increased due to the rise in the temperature until it forces the liquid fuel out of the first critical region through the heat exchanger and into the second critical region, which is at a lower temperature and consequently a lower vapor pressure. The above reaction is repeated in the second critical region and the liquid fuel is forced back into the first critical region. In this manner criticality is achieved alternately in each critical region and power is extracted by the heat exchanger from the liquid fuel passing therethrough. The vapor region and the heat exchanger have a non-critical geometry and reactivity control is effected by conventional control rods in the critical regions.

  10. Analytical solutions for efficient interpretation of single-well push-pull tracer tests

    EPA Science Inventory

    Single-well push-pull tracer tests have been used to characterize the extent, fate, and transport of subsurface contamination. Analytical solutions provide one alternative for interpreting test results. In this work, an exact analytical solution to two-dimensional equations descr...

  11. Octopus movement: push right, go left.

    PubMed

    Hooper, Scott L

    2015-05-04

    Octopus arms have essentially infinite degrees of freedom. New research shows that, despite this potentially great complexity, to locomote octopuses simply elongate one or more arms, thus pushing the body in the opposite direction, and do so without activating the arms in an ordered pattern. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. "Parent Trigger" Push Stirs Debate on Impact

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2012-01-01

    State lawmakers and community activists are making a new push for "parent trigger" laws, measures that let parents vote to convert academically struggling schools to charters or to radically restructure them in other ways. But proponents and critics of the often-controversial, citizen-led efforts are divided on just how profound an…

  13. Formative Assessment Probes: Pushes and Pulls

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    When the concept of force is first taught in the elementary curriculum, it is usually introduced as a push or a pull. The recently released "A Framework for K-12 Science Education" describes grade band endpoints for the Core Idea: Motion and Stability: Forces and Interactions (NRC 2011). It states that by the end of grade 2 students should know…

  14. Pushing the Limit: A Class Project

    ERIC Educational Resources Information Center

    Odafe, Victor U.

    2012-01-01

    Instructors are constantly struggling to help students understand mathematical concepts as well as the relevance of mathematics to the real world. In calculus, students possess misconceptions of the limit concept. "Pushing the Limit" refers to a semester-long calculus class project that required students to read about, interview calculus…

  15. Motivation and Perception of Tourists as Push and Pull Factors to Visit National Park

    NASA Astrophysics Data System (ADS)

    Said, Jumrin; Maryono

    2018-02-01

    Push-pull theoretical framework is a popular theory to explain the reason why the tourists decide to visit the destination rather than other place, the kind of experience they want to get and the type of activity they want to do. In this paper, it is explained the motivation as push factors and the perception as pull factors of the tourist in deciding the destination based on previous literature and research using descriptive method. The framework asumed that tourists are motivated to fulfill their needs, including to reduce the psychological imbalance and to gain recognition of social status. National Park is one of destination based on nature or commonly knowns as ecotourism. In choosing the destination, the tourists tend to classify their alternative choice based on several criteria, such as the domination perception of tourist from one destination (pull factor), self motivation (push factor) and the available time and money (situational constraints).

  16. Pulse width modulated push-pull driven parallel resonant converter with active free-wheel

    DOEpatents

    Reass, William A.; Schrank, Louis

    2004-06-22

    An apparatus and method for high frequency alternating power generation to control kilowatts of supplied power in microseconds. The present invention includes a means for energy storage, push-pull switching means, control electronics, transformer means, resonant circuitry and means for excess energy recovery, all in electrical communication. A push-pull circuit works synchronously with a force commutated free-wheel transistor to provide current pulses to a transformer. A change in the conduction angle of the push-pull circuit changes the amount of energy coupled into the transformer's secondary oscillating circuit, thereby altering the induced secondary resonating voltage. At the end of each pulse, the force commutated free-wheel transistor causes residual excess energy in the primary circuit to be transmitted back to the storage capacitor for later use.

  17. Push-pull switching power amplifier

    NASA Technical Reports Server (NTRS)

    Cuk, Slobodan M. (Inventor)

    1980-01-01

    A true push-pull switching power amplifier is disclosed utilizing two dc-to-dc converters. Each converter is comprised of two inductances, one inductance in series with a DC source and the other inductor in series with the output load, and an electrical energy transferring device with storage capability, namely storage capacitance, with suitable switching means between the inductances to obtain DC level conversion, where the switching means allows bidirectional current (and power) flow, and the switching means of one dc-to-dc converter is driven by the complement of a square-wave switching signal for the other dc-to-dc converter for true push-pull operation. For reduction of current ripple, the inductances in each of the two converters may be coupled, and with proper design of the coupling, the ripple can be reduced to zero at either the input or the output, but preferably the output.

  18. An inhibitory pull-push circuit in frontal cortex.

    PubMed

    Garcia-Junco-Clemente, Pablo; Ikrar, Taruna; Tring, Elaine; Xu, Xiangmin; Ringach, Dario L; Trachtenberg, Joshua T

    2017-03-01

    Push-pull is a canonical computation of excitatory cortical circuits. By contrast, we identify a pull-push inhibitory circuit in frontal cortex that originates in vasoactive intestinal polypeptide (VIP)-expressing interneurons. During arousal, VIP cells rapidly and directly inhibit pyramidal neurons; VIP cells also indirectly excite these pyramidal neurons via parallel disinhibition. Thus, arousal exerts a feedback pull-push influence on excitatory neurons-an inversion of the canonical push-pull of feedforward input.

  19. On the Push-Pull Mobile Learning of Electric Welding

    ERIC Educational Resources Information Center

    Chung, Chih-Chao; Dzan, Wei-Yuan; Cheng, Yuh-Ming; Lou, Shi-Jer

    2017-01-01

    This study aims to explore the learning effects and attitudes of students in the course electric welding practice in a university of science and technology to which the push-pull technology-based mobile learning system is applied. In this study, the push-pull technology is adopted to establish a mobile learning system and develop the Push-pull…

  20. 49 CFR 392.63 - Towing or pushing loaded buses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.63 Towing or pushing loaded buses. No disabled bus with passengers aboard shall be towed or pushed; nor shall any person use or permit to be used a bus with... 49 Transportation 5 2010-10-01 2010-10-01 false Towing or pushing loaded buses. 392.63 Section 392...

  1. Comb-push Ultrasound Shear Elastography (CUSE) with Various Ultrasound Push Beams

    PubMed Central

    Song, Pengfei; Urban, Matthew W.; Manduca, Armando; Zhao, Heng; Greenleaf, James F.; Chen, Shigao

    2013-01-01

    Comb-push Ultrasound Shear Elastography (CUSE) has recently been shown to be a fast and accurate two-dimensional (2D) elasticity imaging technique that can provide a full field-of- view (FOV) shear wave speed map with only one rapid data acquisition. The initial version of CUSE was termed U-CUSE because unfocused ultrasound push beams were used. In this paper, we present two new versions of CUSE – Focused CUSE (F-CUSE) and Marching CUSE (M-CUSE), which use focused ultrasound push beams to improve acoustic radiation force penetration and produce stronger shear waves in deep tissues (e.g. kidney and liver). F-CUSE divides transducer elements into several subgroups which transmit multiple focused ultrasound beams simultaneously. M-CUSE uses more elements for each focused push beam and laterally marches the push beams. Both F-CUSE and M-CUSE can generate comb-shaped shear wave fields that have shear wave motion at each imaging pixel location so that a full FOV 2D shear wave speed map can be reconstructed with only one data acquisition. Homogeneous phantom experiments showed that U-CUSE, F-CUSE and M-CUSE can all produce smooth shear wave speed maps with accurate shear wave speed estimates. An inclusion phantom experiment showed that all CUSE methods could provide good contrast between the inclusion and background with sharp boundaries while F-CUSE and M-CUSE require shorter push durations to achieve shear wave speed maps with comparable SNR to U-CUSE. A more challenging inclusion phantom experiment with a very stiff and deep inclusion shows that better shear wave penetration could be gained by using F-CUSE and M-CUSE. Finally, a shallow inclusion experiment showed that good preservations of inclusion shapes could be achieved by both U-CUSE and F-CUSE in the near field. Safety measurements showed that all safety parameters are below FDA regulatory limits for all CUSE methods. These promising results suggest that, using various push beams, CUSE is capable of

  2. Push-pull vs captodative aromaticity.

    PubMed

    Shainyan, Bagrat A; Fettke, Anja; Kleinpeter, Erich

    2008-10-30

    Vinylogs of fulvalenes with cyclopropenyl and cyclopentadienyl moieties attached either to different carbon atoms ( c-C 3H 2CHCHC 5H 4- c, 7) or to the same carbon atom [XC( c-C 3H 2)( c-C 5H 4), 10] [X = CH 2; C(CN) 2; C(NH 2) 2; C(OCH 2) 2; O; c-C 3H 2; c-C 5H 4; SiH 2; CCl 2] of the double bond inserted between the two rings are examined theoretically at the B3LYP/6-311G(d,p) level. Both types of compounds are shown to possess aromaticity, which was called "push-pull" and "captodative" aromaticity, respectively. For the captodative mesoionic structures XC( c-C 3H 2)( c-C 5H 4), the presence of both the two aromatic moieties and the CC double bond is the necessary and sufficient condition for their existence as energetic minima on the potential energy surface. Aromatic stabilization energy (ASE) was assessed by the use of homodesmotic reactions and heats of hydrogenation. Spatial magnetic criteria (through space NMR shieldings, TSNMRS) of the two types of vinylogous fulvalenes 7 and 10 have been calculated by the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept of Paul von Rague Schleyer, and visualized as iso-chemical-shielding surfaces (ICSS) of various sizes and directions. TSNMRS values can be successfully employed to visualize and quantify the partial push-pull and captodative aromaticity of both the three- and five-membered ring moieties. In addition, the push -pull effect in compounds 7 and 10 could be quantified by the occupation quotient pi* CC/pi CC of the double bond inserted between the two rings.

  3. Particle Engulfment and Pushing by Solidifying Interfaces

    NASA Technical Reports Server (NTRS)

    Stefanescu, Doru M.; Juretzko, Frank R.; Dhindaw, Brij K.; Sen, Subhayu; Curren, Peter A.

    1999-01-01

    The scientific objectives of the work on Particle Engulfment and Pushing by Solidifying Interfaces (PEP) include: (1) to enhance the fundamental understanding of the physics of interaction between inert particles and the solidification interface, and (2) to investigate aspects of melt processing of particulate metal matrix composites in the unique microgravity environment that will yield some vital information for terrestrial applications. The proposal itself calls for a long-term effort on the Space Station. This paper reports on ground experiments performed to date, as well as on the results obtained from two flight opportunities, the LMS mission (1996) and the USMP-4 mission (1997).

  4. (Super)gelators derived from push-pull chromophores: synthesis, gelling properties and second harmonic generation.

    PubMed

    Belén Marco, A; Gindre, Denis; Iliopoulos, Konstantinos; Franco, Santiago; Andreu, Raquel; Canevet, David; Sallé, Marc

    2018-04-04

    The present work takes advantage of the self-assembly process occurring along organogelation, to organize Second Harmonic Generation (SHG) active chromophores. To do so, three push-pull chromophores endowed with a dodecyl urea chain were synthesized and characterized. Their organogelating properties were studied in a wide range of solvents. Despite similar architectures, these derivatives exhibit very different gelling properties, from supergelation to the absence of gelling ability. The utilization of the Hansen solubility parameters allows for observing clear relationships between the gelled solvents and critical gelation concentrations. By evaporating the solvents from the organogels, xerogel materials were prepared and systematically studied by means of optical and electron microscopy as well as SHG microscopy. These studies demonstrate the critical role of the solvent over material structuring and allow generalizing the approach exploiting organogelation as a structuring tool to spontaneously organize push-pull chromophores into SHG-active materials.

  5. Multi-fragment site-directed mutagenic overlap extension polymerase chain reaction as a competitive alternative to the enzymatic assembly method.

    PubMed

    Wäneskog, Marcus; Bjerling, Pernilla

    2014-01-01

    Methods for introducing multiple site-directed mutations are important experimental tools in molecular biology. Research areas that use these methods include the investigation of various protein modifications in cellular processes, modifying proteins for efficient recombinant expression, and the stabilization of mRNAs to allow for increased protein expression. Introducing multiple site-directed mutations is also an important tool in the field of synthetic biology. There are two main methods used in the assembling of fragments generated by mutagenic primers: enzymatic assembly and overlap extension polymerase chain reaction (OE-PCR). In this article, we present an improved OE-PCR method that can be used for the generation of large DNA fragments (up to 7.4 kb) where at least 13 changes can be introduced using a genomic template. The improved method is faster (due to fewer reaction steps) and more accurate (due to fewer PCR cycles), meaning that it can effectively compete with the enzymatic assembly method. Data presented here show that the site-directed mutations can be introduced anywhere between 50 and 1800 bp from each other. The method is highly reliable and predicted to be applicable to most DNA engineering when the introduction of multiple changes in a DNA sequence is required. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Spatial gene drives and pushed genetic waves.

    PubMed

    Tanaka, Hidenori; Stone, Howard A; Nelson, David R

    2017-08-08

    Gene drives have the potential to rapidly replace a harmful wild-type allele with a gene drive allele engineered to have desired functionalities. However, an accidental or premature release of a gene drive construct to the natural environment could damage an ecosystem irreversibly. Thus, it is important to understand the spatiotemporal consequences of the super-Mendelian population genetics before potential applications. Here, we use a reaction-diffusion model for sexually reproducing diploid organisms to study how a locally introduced gene drive allele spreads to replace the wild-type allele, although it possesses a selective disadvantage s > 0. Using methods developed by Barton and collaborators, we show that socially responsible gene drives require 0.5 < s < 0.697, a rather narrow range. In this "pushed wave" regime, the spatial spreading of gene drives will be initiated only when the initial frequency distribution is above a threshold profile called "critical propagule," which acts as a safeguard against accidental release. We also study how the spatial spread of the pushed wave can be stopped by making gene drives uniquely vulnerable ("sensitizing drive") in a way that is harmless for a wild-type allele. Finally, we show that appropriately sensitized drives in two dimensions can be stopped, even by imperfect barriers perforated by a series of gaps.

  7. F-electron systems: Pushing band theory

    SciTech Connect

    Koelling, D.D.

    1990-08-01

    The f-electron orbitals have always been the incomplete atomic shell acting as a local moment weakly interacting with the remaining electronic structure'' in the minds of most people. So examining them using a band theory where one views them as itinerant once was -- and to some extent even today still is -- considered with some skepticism. Nonetheless, a very significant community has successfully utilized band theory as a probe of the electronic structure of the appropriate actinides and rare earths. Those people actually using the approach would be the first to declare that it is not the whole solution.more » Instead, one is pushing and even exceeding its limits of applicability. However, the appropriate procedure is to push the model consistently to its limits, patch where possible, and then look to see where discrepancies remain. I propose to offer a selected review of past developments (emphasizing the career to date of A. J. Freeman in this area), offer a list of interesting puzzles for the future, and then make some guesses as to the techniques one might want to use. 27 refs.« less

  8. Spatial gene drives and pushed genetic waves

    PubMed Central

    Tanaka, Hidenori; Stone, Howard A.; Nelson, David R.

    2017-01-01

    Gene drives have the potential to rapidly replace a harmful wild-type allele with a gene drive allele engineered to have desired functionalities. However, an accidental or premature release of a gene drive construct to the natural environment could damage an ecosystem irreversibly. Thus, it is important to understand the spatiotemporal consequences of the super-Mendelian population genetics before potential applications. Here, we use a reaction–diffusion model for sexually reproducing diploid organisms to study how a locally introduced gene drive allele spreads to replace the wild-type allele, although it possesses a selective disadvantage s > 0. Using methods developed by Barton and collaborators, we show that socially responsible gene drives require 0.5 < s < 0.697, a rather narrow range. In this “pushed wave” regime, the spatial spreading of gene drives will be initiated only when the initial frequency distribution is above a threshold profile called “critical propagule,” which acts as a safeguard against accidental release. We also study how the spatial spread of the pushed wave can be stopped by making gene drives uniquely vulnerable (“sensitizing drive”) in a way that is harmless for a wild-type allele. Finally, we show that appropriately sensitized drives in two dimensions can be stopped, even by imperfect barriers perforated by a series of gaps. PMID:28743753

  9. Kinetic analysis of several variations of push-ups.

    PubMed

    Ebben, William P; Wurm, Bradley; VanderZanden, Tyler L; Spadavecchia, Mark L; Durocher, John J; Bickham, Curtis T; Petushek, Erich J

    2011-10-01

    Push-ups are a common and practical exercise that is used to enhance fitness, including upper body strength or endurance. The kinetic characteristics of push-ups and its variations are yet to be quantified. Kinetic quantification is necessary to accurately evaluate the training load, and thus the nature of the training stimulus, for these exercise variations. This study assessed the peak vertical ground reaction forces (GRFs) of push-up variations including the regular push-up and those performed with flexed knee, feet elevated on a 30.48-cm box, and a 60.96-cm box, and hands elevated on a 30.48-cm box and a 60.96-cm box. Twenty-three recreationally fit individuals (14 men, 9 women) performed each of the 6 push-up variations in a randomized order. Peak GRF and peak GRF expressed as a coefficient of subject body mass were obtained with a force platform. Push-ups with the feet elevated produced a higher GRF than all other push-up variations (p ≤ 0.05). Push-ups with hands elevated and push-ups from the flexed knee position produced a lower GRF than all other push-up variations (p ≤ 0.05). No gender differences in response to these push-up variations were found (p > 0.05). Additionally, subject height was not related to the GRF for any of the push-up conditions (p > 0.05) other than the condition where hands were elevated on a 60.96-cm box (p ≤ 0.05; r = 0.63). These data can be used to progress the intensity of push-ups in a program and to quantify the training load as a percentage of body mass.

  10. PUSH(ing) Limits: Using Fiction in the Classroom for Human Behavior and the Social Environment

    ERIC Educational Resources Information Center

    Mendoza, Natasha S.; Bonta, Kimberly; Horn, Philip; Moore, Erin; Gibson, Allison; Simmons, David

    2012-01-01

    The use of fiction and autobiography in social science course work has been shown to enhance students' learning experience. Using the novel PUSH, by Sapphire, we designed a curriculum supplement for the social work course, human behavior and the social environment (HBSE) that encourages students to integrate course content in an innovative way and…

  11. Rat mir-155 generated from the lncRNA Bic is ‘hidden’ in the alternate genomic assembly and reveals the existence of novel mammalian miRNAs and clusters

    PubMed Central

    Uva, Paolo; Da Sacco, Letizia; Del Cornò, Manuela; Baldassarre, Antonella; Sestili, Paola; Orsini, Massimiliano; Palma, Alessia; Gessani, Sandra; Masotti, Andrea

    2013-01-01

    MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as post-transcriptional gene expression regulators in many physiological and pathological conditions. During the last few years, many novel mammalian miRNAs have been predicted experimentally with bioinformatics approaches and validated by next-generation sequencing. Although these strategies have prompted the discovery of several miRNAs, the total number of these genes still seems larger. Here, by exploiting the species conservation of human, mouse, and rat hairpin miRNAs, we discovered a novel rat microRNA, mir-155. We found that mature miR-155 is overexpressed in rat spleen myeloid cells treated with LPS, similarly to humans and mice. Rat mir-155 is annotated only on the alternate genome, suggesting the presence of other “hidden” miRNAs on this assembly. Therefore, we comprehensively extended the homology search also to mice and humans, finally validating 34 novel mammalian miRNAs (two in humans, five in mice, and up to 27 in rats). Surprisingly, 15 of these novel miRNAs (one for mice and 14 for rats) were found only on the alternate and not on the reference genomic assembly. To date, our findings indicate that the choice of genomic assembly, when mapping small RNA reads, is an important option that should be carefully considered, at least for these animal models. Finally, the discovery of these novel mammalian miRNA genes may contribute to a better understanding of already acquired experimental data, thereby paving the way to still unexplored investigations and to unraveling the function of miRNAs in disease models. PMID:23329697

  12. Revised Push-Up Test Norms for College Students

    ERIC Educational Resources Information Center

    Baumgartner, Ted A.; Hales, Derek; Chung, Hyuk; Oh, Suhak; Wood, Heather M.

    2004-01-01

    A revised push-up test for college students was presented in 2002. The purpose of this study was to develop percentile norms for the revised push-up test when it is used with college students. Revised push-up scores collected on 177 male and 274 female college students were used to develop percentile norms. The norms for the men have a different…

  13. Infrared SWAP detectors: pushing the limits

    NASA Astrophysics Data System (ADS)

    Reibel, Yann; Taalat, R.; Brunner, A.; Rubaldo, L.; Augey, T.; Kerlain, A.; Péré-Laperne, N.; Manissadjian, A.; Gravrand, O.; Castelein, P.; Destéfanis, G.

    2015-06-01

    The growing demand for compact and low consumption infrared cooled detectors is driven by different products segments. Hand Held Thermal Imagers, UAV, small gimbals are some of them. End users are requiring devices easy to use with fast cool down time, excellent portability, low acoustic noise with no trade-offs in reliability and performance. These requirements are pushing the technology developments toward constant innovations on detectors, coolers, read out circuits and proximity electronic boards. In this paper we are discussing the different figures of merit and highlighting the challenges for the different components. An update on the developments of HOT technology for most advanced pixel pitch will be presented. Very compact products are driving the developments for innovative coolers and cryogenic solutions. A low power compact architecture is a must for electronic boards to optimize the overall system power consumption. Finally a look to the future requirements for further shrink will be addressed.

  14. The alternative strategy for designing covalent drugs through kinetic effects of pi-stacking on the self-assembled nanoparticles: a model study with antibiotics

    NASA Astrophysics Data System (ADS)

    Du, Libo; Suo, Siqingaowa; Zhang, Han; Jia, Hongying; Liu, Ke Jian; Zhang, Xue Ji; Liu, Yang

    2016-11-01

    It is still a huge challenge to find a new strategy for rationally designing covalent drugs because most of them are discovered by serendipity. Considering that the effect of covalent drugs is closely associated with the kinetics of the reaction between drug molecule and its target protein, here we first demonstrate an example of the kinetic effect of pi-stacking of drug molecules on covalent antimicrobial drug design. When PEGylated 7-aminocephalosporanic acid (PEG-ACA) is used as a substrate drug, pi-stacking of the ACA group via the self-assembly of PEG-ACA on the surface of gold nanoparticles (i.e. Au@ACA) exhibits antibacterial activity against E. coli fourfold higher than a PEG-ACA monomer does. The reason can be reasonably attributed to the kinetic rate enhancement for the covalent reaction between Au@ACA and penicillin binding proteins. We believe that the self-assembly of functional groups onto the surface of gold nanoparticles represents a new strategy for covalent drug design.

  15. Why People Choose to Teach in Urban Schools: The Case for a Push-Pull Factor Analysis

    ERIC Educational Resources Information Center

    Knell, Paul F.; Castro, Antonio J.

    2014-01-01

    This qualitative research study traces the motivations for teaching of 13 teacher candidates enrolled in an urban-based alternative certification program. After using a push-pull factor analysis, the data suggest that most participants left their previous careers due to financial shortcomings or work instability. As a result, these participants…

  16. High aspect ratio, remote controlled pumping assembly

    DOEpatents

    Brown, Steve B.; Milanovich, Fred P.

    1995-01-01

    A miniature dual syringe-type pump assembly which has a high aspect ratio and which is remotely controlled, for use such as in a small diameter penetrometer cone or well packer used in water contamination applications. The pump assembly may be used to supply and remove a reagent to a water contamination sensor, for example, and includes a motor, gearhead and motor encoder assembly for turning a drive screw for an actuator which provides pushing on one syringe and pulling on the other syringe for injecting new reagent and withdrawing used reagent from an associated sensor.

  17. High aspect ratio, remote controlled pumping assembly

    DOEpatents

    Brown, S.B.; Milanovich, F.P.

    1995-11-14

    A miniature dual syringe-type pump assembly is described which has a high aspect ratio and which is remotely controlled, for use such as in a small diameter penetrometer cone or well packer used in water contamination applications. The pump assembly may be used to supply and remove a reagent to a water contamination sensor, for example, and includes a motor, gearhead and motor encoder assembly for turning a drive screw for an actuator which provides pushing on one syringe and pulling on the other syringe for injecting new reagent and withdrawing used reagent from an associated sensor. 4 figs.

  18. Analysis of large space structures assembly: Man/machine assembly analysis

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Procedures for analyzing large space structures assembly via three primary modes: manual, remote and automated are outlined. Data bases on each of the assembly modes and a general data base on the shuttle capabilities to support structures assembly are presented. Task element times and structure assembly component costs are given to provide a basis for determining the comparative economics of assembly alternatives. The lessons learned from simulations of space structures assembly are detailed.

  19. SHOULDER KINEMATICS DURING THE PUSH-UP PLUS EXERCISE

    PubMed Central

    Lunden, Jason B; Braman, Jonathan P; LaPrade, Robert F; Ludewig, Paula M

    2009-01-01

    Background and Hypothesis The push-up plus exercise is a common therapeutic exercise for improving shoulder function and treating shoulder pathology. To date, the kinematics of the push-up plus exercise have not been studied. Our hypothesis was that the push-up plus exercise would demonstrate increased scapular internal rotation and increased humeral anterior translation during the plus phase of the exercise, potentially impacting the subacromial space. Methods Bone pins were inserted in the humerus and scapula in 12 healthy volunteers with no history of shoulder pathology. In vivo motion during the wall push-up plus exercise was tracked using an electromagnetic tracking system. Results During the wall push-up plus exercise, from a starting position to the push-up plus position, there was a significant increase in scapular downward rotation (p<0.05) and internal rotation (p<0.05). The pattern of glenohumeral motion was humeral elevation (p<0.05) and movement anterior to the scapular plane (p<0.05) with humeral external rotation remaining relatively constant. Conclusions We found that during a wall push-up plus exercise in healthy volunteers, the scapula was placed in a position potentially associated with shoulder impingement. Due to the shoulder kinematics of the wall push-up plus exercise, utilization of this exercise without modification early on in shoulder rehabilitation, especially in patients with subacromial impingement, may not be advised. Level of evidence Laboratory Study PMID:19733487

  20. Tracer gas evaluations of push-pull ventilation system performance.

    PubMed

    Ojima, Jun

    2009-01-01

    A push-pull ventilation system is effective for hazardous material exhaustion. Although a push-pull ventilation system has advantages over a local exhaust hood, some laborious adjustments are required. The pertinence of the adjustments is uncertain because it is difficult to evaluate the performance of a push-pull ventilation system quantitatively. In this study, a measurement of the capture efficiency of a push-pull ventilation system was carried out by means of a tracer gas method. The capture efficiency decreased to 39.3-78.5% when blockage material, a dummy worker and a cross draft, were set in the ventilation zone, but the efficiency was 95.1-97.9% when the cross draft was stopped. The results suggest that the uniform flow of a push-pull ventilation system will detour a blockage and the performance of the system will not be reduced unless a cross draft disturbs the uniform flow.

  1. Assembly and use of high-density recombinant peptide chips for large-scale ligand screening is a practical alternative to synthetic peptide libraries.

    PubMed

    Hundsberger, Harald; Önder, Kamil; Schuller-Götzburg, Peter; Virok, Dezso P; Herzog, Julia; Rid, Raphaela

    2017-06-08

    Recombinant peptide chips could constitute a versatile complementation to state-of-the-art in situ (chemical on-chip) synthesis, particle-based printing, or pre-manufactured peptide spotting. Bottlenecks still impeding a routine implementation - from restricted peptide lengths, low diversity and low array densities to high costs - could so be overcome. To assess overall performance, we assembled recombinant chips composed of 38,400 individual peptide spots on the area of a standard 96-well microtiter plate from comprehensive, highly diverse (>107 single clones) short random peptide libraries. Screening of altogether 476,160 clones against Streptavidin uncovered 2 discrete new binders: a characteristic HPQ-motif containing VSHPQAPF and a cyclic CSGSYGSC peptide. Interactions were technically confirmed by fluorescence polarization as well as biolayer-interferometry, and their potential suitability as novel detection tags evaluated by detection of a peptide-fused exemplary test protein. From our data we conclude that the presented technical pipeline can reliably identify novel hits, useful as first-generation binders or templates for subsequent ligand design plus engineering.

  2. Surface/Interface Carrier-Transport Modulation for Constructing Photon-Alternative Ultraviolet Detectors Based on Self-Bending-Assembled ZnO Nanowires.

    PubMed

    Guo, Zhen; Zhou, Lianqun; Tang, Yuguo; Li, Lin; Zhang, Zhiqi; Yang, Hongbo; Ma, Hanbin; Nathan, Arokia; Zhao, Dongxu

    2017-09-13

    Surface/interface charge-carrier generation, diffusion, and recombination/transport modulation are especially important in the construction of photodetectors with high efficiency in the field of nanoscience. In the paper, a kind of ultraviolet (UV) detector is designed based on ZnO nanostructures considering photon-trapping, surface plasmonic resonance (SPR), piezophototronic effects, interface carrier-trapping/transport control, and collection. Through carefully optimized surface/interface carrier-transport modulation, a designed device with detectivity as high as 1.69 × 10 16 /1.71 × 10 16 cm·Hz 1/2 /W irradiating with 380 nm photons under ultralow bias of 0.2 V is realized by alternating nanoparticle/nanowire active layers, respectively, and the designed UV photodetectors show fast and slow recovery processes of 0.27 and 4.52 ms, respectively, which well-satisfy practical needs. Further, it is observed that UV photodetection could be performed within an alternative response by varying correlated key parameters, through efficient surface/interface carrier-transport modulation, spectrally resolved photoresponse of the detector revealing controlled detection in the UV region based on the ZnO nanomaterial, photodetection allowed or limited by varying the active layers, irradiation distance from one of the electrodes, standing states, or electric field. The detailed carrier generation, diffusion, and recombination/transport processes are well illustrated to explain charge-carrier dynamics contributing to the photoresponse behavior.

  3. Particle Engulfment and Pushing By Solidifying Interfaces

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The study of particle behavior at solid/liquid interfaces (SLI s) is at the center of the Particle Engulfment and Pushing (PEP) research program. Interactions of particles with SLI s have been of interest since the 1960 s, starting with geological observations, i.e., frost heaving. Ever since, this field of research has become significant to such diverse areas as metal matrix composite materials, fabrication of superconductors, and inclusion control in steels. The PEP research effort is geared towards understanding the fundamental physics of the interaction between particles and a planar SLI. Experimental work including 1-g and mu-g experiments accompany the development of analytical and numerical models. The experimental work comprised of substantial groundwork with aluminum (Al) and zinc (Zn) matrices containing spherical zirconia particles, mu-g experiments with metallic Al matrices and the use of transparent organic metal-analogue materials. The modeling efforts have grown from the initial steady-state analytical model to dynamic models, accounting for the initial acceleration of a particle at rest by an advancing SLI. To gain a more comprehensive understanding, numerical models were developed to account for the influence of the thermal and solutal field. Current efforts are geared towards coupling the diffusive 2-D front tracking model with a fluid flow model to account for differences in the physics of interaction between 1-g and -g environments. A significant amount of this theoretical investigation has been and is being performed by co-investigators at NASA MSFC.

  4. Bacteriophage Assembly

    PubMed Central

    Aksyuk, Anastasia A.; Rossmann, Michael G.

    2011-01-01

    Bacteriophages have been a model system to study assembly processes for over half a century. Formation of infectious phage particles involves specific protein-protein and protein-nucleic acid interactions, as well as large conformational changes of assembly precursors. The sequence and molecular mechanisms of phage assembly have been elucidated by a variety of methods. Differences and similarities of assembly processes in several different groups of bacteriophages are discussed in this review. The general principles of phage assembly are applicable to many macromolecular complexes. PMID:21994726

  5. Benefit of "Push-pull" Locomotion for Planetary Rover Mobility

    NASA Technical Reports Server (NTRS)

    Creager, Colin M.; Moreland, Scott Jared; Skonieczny, K.; Johnson, K.; Asnani, V.; Gilligan, R.

    2011-01-01

    As NASAs exploration missions on planetary terrains become more aggressive, a focus on alternative modes of locomotion for rovers is necessary. In addition to climbing steep slopes, the terrain in these extreme environments is often unknown and can be extremely hard to traverse, increasing the likelihood of a vehicle or robot becoming damaged or immobilized. The conventional driving mode in which all wheels are either driven or free-rolling is very efficient on flat hard ground, but does not always provide enough traction to propel the vehicle through soft or steep terrain. This paper presents an alternative mode of travel and investigates the fundamental differences between these locomotion modes. The methods of push-pull locomotion discussed can be used with articulated wheeled vehicles and are identified as walking or inchinginch-worming. In both cases, the braked non-rolling wheels provide increased thrust. An in-depth study of how soil reacts under a rolling wheel vs. a braked wheel was performed by visually observing the motion of particles beneath the surface. This novel technique consists of driving or dragging a wheel in a soil bin against a transparent wall while high resolution, high-rate photographs are taken. Optical flow software was then used to determine shearing patterns in the soil. Different failure modes were observed for the rolling and braked wheel cases. A quantitative comparison of inching vs. conventional driving was also performed on a full-scale vehicle through a series of drawbar pull tests in the Lunar terrain strength simulant, GRC-1. The effect of tire stiffness was also compared; typically compliant tires provide better traction when driving in soft soil, however its been observed that rigid wheels may provide better thrust when non-rolling. Initial tests indicate up to a possible 40 increase in pull force capability at high slip when inching vs. rolling.

  6. Electromyographic Comparison of Traditional and Suspension Push-Ups

    PubMed Central

    Snarr, Ronald L.; Esco, Michael R.

    2013-01-01

    There is very limited scientific data concerning suspension training. The purpose of this investigation was to compare the electromyographic activity of the pectoralis major, anterior deltoid, and triceps brachii between a suspension push-up and traditional push-up. Twenty-one apparently healthy men (n = 15, age = 25.93 ± 3.67 years) and women (n = 6, age = 23.5 ± 1.97 years) volunteered to participate in this study. All subjects performed four repetitions of a suspension push-up and a traditional push-up where the order of the exercises was randomized. The mean peak and normalized electromyography of the pectoralis major, anterior deltoid, and triceps brachii were compared across the two exercises. Suspension push-ups elicited the following electromyographic values: pectoralis major (3.08 ± 1.13 mV, 69.54 ± 27.6 %MVC), anterior deltoid (5.08 ± 1.55 mV, 81.13 ± 17.77 %MVC), and triceps brachii (5.11 ± 1.97 mV, 105.83 ± 18.54 %MVC). The electromyographic activities during the traditional push-up were as follows: pectoralis major (2.66 ± 1.05 mV, 63.62 ± 16.4 %MVC), anterior deltoid (4.01 ± 1.27 mV, 58.91 ± 20.3 %MVC), and triceps brachii (3.91 ± 1.36 mV, 74.32 ± 16.9 %MVC). The mean peak and normalized electromyographic values were significantly higher for all 3 muscles during the suspension push-up compared to the traditional push-up (p < 0.05). This study suggests that the suspension push-up elicited a greater activation of pectoralis major, anterior deltoid, and triceps brachii when compared to a traditional push-up. Therefore, suspension push-ups may be considered an advanced variation of a traditional push-up when a greater challenge is warranted. PMID:24511343

  7. Exact Solution of a Drop-Push Model for Percolation

    NASA Astrophysics Data System (ADS)

    Majumdar, Satya N.; Dean, David S.

    2002-08-01

    Motivated by a computer science algorithm known as ``linear probing with hashing,'' we study a new type of percolation model whose basic features include a sequential ``dropping'' of particles on a substrate followed by their transport via a ``pushing'' mechanism. Our exact solution in one dimension shows that, unlike the ordinary random percolation model, the drop-push model has nontrivial spatial correlations generated by the dynamics itself. The critical exponents in the drop-push model are also different from those of the ordinary percolation. The relevance of our results to computer science is pointed out.

  8. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  9. Using Field Data to Improve Authorized Stockage List Push Packages

    DTIC Science & Technology

    2011-01-01

    List RBS Readiness Based Sparing RO Requisition Objective ROP Reorder Point SAP Systems Applications and Products SESAME Selective Stockage for... Stockage List Push Packages 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...reviewed, they are not expected to be comprehensive and may present preliminary findings. Using Field Data to Improve Authorized Stockage List Push

  10. Push and pull strategies: applications for health care marketing.

    PubMed

    Kingsley, B R

    1987-08-01

    As health care markets mature and expand, strategies available in other industries become useful. This article examines how traditional push-pull strategies apply to health care. Marketers using a push strategy recognize that the sale of their services or goods is dependent upon the endorsement of a middleman and promote their product through the middleman. Those using a pull strategy market directly to the consumer. In this article, the author outlines the advantages and disadvantages of using each strategy.

  11. RNA-Seq analysis and annotation of a draft blueberry genome assembly identifies candidate genes involved in fruit ripening, biosynthesis of bioactive compounds, and stage-specific alternative splicing.

    PubMed

    Gupta, Vikas; Estrada, April D; Blakley, Ivory; Reid, Rob; Patel, Ketan; Meyer, Mason D; Andersen, Stig Uggerhøj; Brown, Allan F; Lila, Mary Ann; Loraine, Ann E

    2015-01-01

    Blueberries are a rich source of antioxidants and other beneficial compounds that can protect against disease. Identifying genes involved in synthesis of bioactive compounds could enable the breeding of berry varieties with enhanced health benefits. Toward this end, we annotated a previously sequenced draft blueberry genome assembly using RNA-Seq data from five stages of berry fruit development and ripening. Genome-guided assembly of RNA-Seq read alignments combined with output from ab initio gene finders produced around 60,000 gene models, of which more than half were similar to proteins from other species, typically the grape Vitis vinifera. Comparison of gene models to the PlantCyc database of metabolic pathway enzymes identified candidate genes involved in synthesis of bioactive compounds, including bixin, an apocarotenoid with potential disease-fighting properties, and defense-related cyanogenic glycosides, which are toxic. Cyanogenic glycoside (CG) biosynthetic enzymes were highly expressed in green fruit, and a candidate CG detoxification enzyme was up-regulated during fruit ripening. Candidate genes for ethylene, anthocyanin, and 400 other biosynthetic pathways were also identified. Homology-based annotation using Blast2GO and InterPro assigned Gene Ontology terms to around 15,000 genes. RNA-Seq expression profiling showed that blueberry growth, maturation, and ripening involve dynamic gene expression changes, including coordinated up- and down-regulation of metabolic pathway enzymes and transcriptional regulators. Analysis of RNA-seq alignments identified developmentally regulated alternative splicing, promoter use, and 3' end formation. We report genome sequence, gene models, functional annotations, and RNA-Seq expression data that provide an important new resource enabling high throughput studies in blueberry.

  12. The "push" for evidence: management of the second stage.

    PubMed

    Roberts, Joyce E

    2002-01-01

    Recognition that the available evidence does not support arbitrary time limits for the second stage of labor has led to reconsideration of the influence of maternal bearing down efforts on fetal/newborn status as well as on maternal pelvic structural integrity. The evidence that the duration of 'active' pushing is associated with fetal acidosis and denervation injury to maternal perineal musculature has contributed to the delineation of at least two phases during second stage, an early phase of continued fetal descent, and a phase of "active" pushing. The basis for the recommendation that the early phase of passive descent be prolonged and the phase of active pushing shortened by strategies to achieve effective, but non-detrimental pushing efforts is reviewed. The rational includes an emphasis on the obstetric factors that are optimal for birth and conducive to efficient maternal bearing down. Explicit assessment of these obstetric factors and observation of maternal behavior, particularly evidence of an involuntary urge to push, should be coupled with the use of maternal positions that will promote fetal descent as well as reduce maternal pain. The use of epidural analgesia for pain relief can also be accompanied by these same principles, although further research is needed to verify the strategies of "delayed pushing" and maintenance of pain relief along with a reconceptualization of the second stage of labor.

  13. Push-out strength of modified Portland cements and resins.

    PubMed

    Iacono, Francesco; Gandolfi, Maria Giovanna; Huffman, Bradford; Sword, Jeremy; Agee, Kelli; Siboni, Francesco; Tay, Franklin; Prati, Carlo; Pashley, David

    2010-02-01

    Modified calcium-silicate cements derived from white Portland cement (PC) were formulated to test their push-out strength from radicular dentin after immersion for 1 month. Slabs obtained from 42 single-rooted extracted teeth were prepared with 0.6 mm diameter holes, then enlarged with rotary instruments. After immersion in EDTA and NaOC1, the holes were filled with modified PCs or ProRoot MTA, Vitrebond and Clearfil SE. Different concentrations of phyllosilicate (montmorillonite-MMT) were added to experimental cements. ProRoot MTA was also included as reference material. Vitrebond and Clearfil SE were included as controls. Each group was tested after 1 month of immersion in water or PBS. A thin-slice push-out test on a universal testing machine served to test the push-out strength of materials. Results were statistically analyzed using the least squares means (LSM) method. The modified PCs had push-out strengths of 3-9.5 MPa after 1 month of immersion in water, while ProRoot MTA had 4.8 MPa. The push-out strength of PC fell after incubation in PBS for 1 month, while the push-out strength of ProRoot MTA increased. There were no significant changes in Clearfil SE Bond or Vitrebond after water or PBS storage.

  14. Utilising UDT to push the bandwidth envelope

    NASA Astrophysics Data System (ADS)

    Garrett, B.; Davies, B.

    eScience applications, in particular High Energy Physics, often involve large amounts of data and/or computing and often require secure resource sharing across organizational boundaries, and are thus not easily handled by today's networking infrastructures. By utilising the switched lightpath connections provided by the UKLight network it has been possible to research the use of alternate protocols for data transport. While the HEP projects make use of a number of middleware solutions for data storage and transport, they all rely on GridFTP for WAN transport. The GridFTP protocol runs over TCP as the layer 3 protocol by default, however with the latest released of the Globus toolkit it is possible to utilise alternate protocols at the layer 3 level. One of the alternatives is a reliable version of UDP called UDT. This report presents the results of the tests measuring the performance of single-threaded file transfers using GridFTP running over both TCP and the UDT protocol.

  15. Field evaluation of a direct push deployed sensor probe for vertical soil water content profiling

    NASA Astrophysics Data System (ADS)

    Vienken, Thomas; Reboulet, Ed; Leven, Carsten; Kreck, Manuel; Zschornack, Ludwig; Dietrich, Peter

    2015-04-01

    Reliable high-resolution information about vertical variations in soil water content, i.e. total porosity in the saturated zone, is essential for flow and transport predictions within the subsurface. However, porosity measurements are often associated with high efforts and high uncertainties, e.g. caused by soil disturbance during sampling or sensor installation procedures. In hydrogeological practice, commonly applied tools for the investigation of vertical soil water content distribution include gravimetric laboratory analyses of soil samples and neutron probe measurements. A yet less well established technique is the use of direct push-deployed sensor probes. Each of these methods is associated with inherent advantages and limitations due to their underlying measurement principles and operation modes. The presented study describes results of a joint field evaluation of the individual methods under different depositional and hydrogeological conditions with special focus on the performance on the direct push-deployed water content profiler. Therefore, direct push-profiling results from three different test sites are compared with results obtained from gravimetric analysis of soil cores and neutron probe measurements. In direct comparison, the applied direct push-based sensor probe proved to be a suitable alternative for vertical soil water content profiling to neutron probe technology, and, in addition, proved to be advantageous over gravimetric analysis in terms vertical resolution and time efficiency. Results of this study identify application-specific limitations of the methods and thereby highlight the need for careful data evaluation, even though neutron probe measurements and gravimetric analyses of soil samples are well established techniques (see Vienken et al. 2013). Reference: Vienken, T., Reboulet, E., Leven, C., Kreck, M., Zschornack, L., Dietrich, P., 2013. Field comparison of selected methods for vertical soil water content profiling. Journal of

  16. Sequence Assembly.

    PubMed

    Huang, Xiaoqiu

    2017-01-01

    We describe an efficient method for assembling short reads into long sequences. In this method, a hashing technique is used to compute overlaps between short reads, allowing base mismatches in the overlaps. Then an overlap graph is constructed, with each vertex representing a read and each edge representing an overlap. The overlap graph is explored by graph algorithms to find unique paths of reads representing contigs. The consensus sequence of each contig is constructed by computing alignments of multiple reads without gaps. This strategy has been implemented as a short read assembly program called PCAP.Solexa. We also describe how to use PCAP. Solexa in assembly of short reads.

  17. A sled push stimulus potentiates subsequent 20-m sprint performance.

    PubMed

    Seitz, Laurent B; Mina, Minas A; Haff, G Gregory

    2017-08-01

    The objective of this study was to examine the potentiating effects of performing a single sprint-style sled push on subsequent unresisted 20m sprint performance. Randomized crossover design. Following a familiarization session, twenty rugby league players performed maximal unresisted 20m sprints before and 15s, 4, 8 and 12min after a single sled push stimulus loaded with either 75 or 125% body mass. The two sled push conditions were performed in a randomized order over a one-week period. The fastest sprint time recorded before each sled push was compared to that recorded at each time point after to determine the post-activation potentiation (PAP) effect. After the 75% body mass sled push, sprint time was 0.26±1.03% slower at the 15s time point (effect size [ES]=0.07) but faster at the 4 (-0.95±2.00%; ES=-0.22), 8 (-1.80±1.43%; ES=-0.42) and 12 (-1.54±1.54%; ES=-0.36)min time points. Sprint time was slower at all the time points after the 125% body mass sled (1.36±2.36%-2.59±2.90%; ESs=0.34-0.64). Twenty-meter sprint performance is potentiated 4-12min following a sled push loaded with 75% body mass while it is impaired after a 125% body mass sled. These results are of great importance for coaches seeking to potentiate sprint performance with the sled push exercise. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. The Alternative Low Noise Fan

    NASA Technical Reports Server (NTRS)

    Dittmar, James H.; Elliott, David M.; Jeracki, Robert J.; Moore, Royce D.; Parrott, Tony L.

    2000-01-01

    A 106 bladed fan with a design takeoff tip speed of 1100 ft/sec was hypothesized as reducing perceived noise because of the shift of the blade passing harmonics to frequencies beyond the perceived noise rating range. A 22 in. model of this Alternative Low Noise Fan, ALNF, was tested in the NASA Glenn 9x 15 Wind Tunnel. 'Me fan was tested with a 7 vane long chord stator assembly and a 70 vane conventional stator assembly in both hard and acoustically treated configurations. In addition a partially treated 7 vane configuration was tested wherein the acoustic material between the 7 long chord stators was made inactive. The noise data from the 106 bladed fan with 7 long chord stators in a hard configuration was shown to be around 4 EPNdB quieter than a low tip speed Allison fan at takeoff and around 5 EPNdB quieter at approach. Although the tone noise behaved as hypothesized, the majority of this noise reduction was from reduced broadband noise related to the large number of rotor blades. This 106 bladed ALNF is a research fan designed to push the technology limits and as such is probably not a practical device with present materials technology. However, a low tip speed fan with around 50 blades would be a practical device and calculations indicate that it could be 2 to 3 EPNdB quieter at takeoff and 3 to 4 EPNdB quieter at approach than the Allison fan. 7 vane data compared with 70 vane data indicated that the tone noise was controlled by rotor wake-stator interaction but that the broadband noise is probably controlled by the interaction of the rotor with incoming flows. A possible multiple pure tone noise reduction technique for a fan/acoustic treatment system was identified. The data from the fully treated configuration showed significant noise reductions over a large frequency range thereby providing a real tribute to this bulk absorber treatment design. The tone noise data with the partially treated 7 vane configuration indicated that acoustic material in the

  19. Seal assembly

    DOEpatents

    Johnson, Roger Neal; Longfritz, William David

    2001-01-01

    A seal assembly that seals a gap formed by a groove comprises a seal body, a biasing element, and a connection that connects the seal body to the biasing element to form the seal assembly. The seal assembly further comprises a concave-shaped center section and convex-shaped contact portions at each end of the seal body. The biasing element is formed from an elastic material and comprises a convex-shaped center section and concave-shaped biasing zones that are opposed to the convex-shaped contact portions. The biasing element is adapted to be compressed to change a width of the seal assembly from a first width to a second width that is smaller than the first width. In the compressed state, the seal assembly can be disposed in the groove. After release of the compressing force, the seal assembly expands. The contact portions will move toward a surface of the groove and the biasing zones will move into contact with another surface of the groove. The biasing zones will bias the contact portions of the seal body against the surface of the groove.

  20. Can antenatal education influence how women push in labour?

    PubMed

    Phipps, Hala; Charlton, Sarah; Dietz, Hans Peter

    2009-06-01

    Antenatal education on the physiology of second stage of labour and effective pushing has not been studied in the literature. Anecdotal observation seems to indicate that some nulliparous women are (at least initially) unable to push effectively. A large proportion seem to reflexly contract the levator ani muscle when asked to push which may have the effect of slowing the progress of labour. To test the effectiveness of structured antenatal education for pushing in the second stage of labour versus normal care and its impact on delivery outcome. One hundred nulliparous women between 35 and 37 weeks gestation were randomised. Two 15-min structured education sessions, one week apart, utilising observation of the perineum and a vaginal examination to teach correct technique for relaxing the levator ani muscle and effective pushing. In both groups, 31 of 50 women (62%) delivered vaginally. Instrumental delivery and caesarean section rates did not differ between the two groups (P = 0.78, relative risk = 1). The mean duration of active second stage for the control group was 53.96 min compared with 57.26 min for the intervention group. This difference of 3.3 min was not statistically significant (P = 0.56). Knowledge of women in the intervention group was increased and the majority of women found the educational sessions helpful. Antenatal teaching to ensure effective maternal pushing in labour did not result in altered obstetric outcomes relative to the control group. However, there was a measurable qualitative effect from the intervention in that women clearly felt the education sessions to be helpful.

  1. Lowering the Age of Consent: Pushing Back against the Anti-Vaccine Movement.

    PubMed

    Whelan, Allison M

    2016-09-01

    This article examines the rise of the anti-vaccination movement, the proliferation of laws allowing parental exemptions to mandatory school vaccines, and the impact of the movement on immunization rates for all vaccines. It uses the ongoing debate about the Human Papillomavirus (HPV) vaccine as an example to highlight the ripple effect and consequences of the anti-vaccine movement despite robust evidence of the vaccine's safety and efficacy. The article scrutinizes how state legislatures ironically promote vaccination while simultaneously deferring to the opposition by promulgating broad opt-outs from mandatory vaccine laws. This article concludes by offering an alternative legislative approach to specifically combat the anti-vaccine movement's impact on HPV vaccination rates. Lowering the age of consent has not been widely attempted or proposed and provides an alternative statutory mechanism to push back against vaccine resistance. © 2016 American Society of Law, Medicine & Ethics.

  2. Biomechanical study of the final push-pull in archery.

    PubMed

    Leroyer, P; Van Hoecke, J; Helal, J N

    1993-02-01

    The purpose of this study was to analyse archery performance among eight archers of different abilities by means of displacement pull-hand measurements during the final push-pull phase of the shoot. The archers showed an irregular displacement negatively related to their technical level. Displacement signal analysis showed high power levels in both the 0-5 Hz and 8-12 Hz ranges. The latter peak corresponds to electromyographic tremor observed during a prolonged push-pull effort. The results are discussed in relation to some potentially helpful training procedures such as biofeedback and strength conditioning.

  3. Influence of push element geometry on the capture efficiency of push-pull ventilation systems in surface treatment tanks.

    PubMed

    Marzal, F; Gonzalez, E; Minana, A; Baeza, A

    2002-06-01

    A full-scale installation which simulates a surface treatment tank provided with a push-pull ventilation system has been designed. This study examines the influence of the geometry of the push element on the capture efficiency of the system. It is observed that: (i) capture efficiency increases with the number of holes because of the continuous curtain formed, the size of the holes having no significant effect within the range studied (5-20 mm diameter); (ii) the push element is best supported on the tank wall so that no air from outside penetrates below the emitting jets because in this way the impact of the curtain on the tank occurs earlier and losses are less; (iii) the best results are obtained when the holes are directed downwards towards the tank surface at an angle of between 22 and 45 degrees.

  4. Hinge assembly

    DOEpatents

    Vandergriff, D.H.

    1999-08-31

    A hinge assembly is disclosed having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf. 8 figs.

  5. Hinge assembly

    DOEpatents

    Vandergriff, David Houston

    1999-01-01

    A hinge assembly having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf.

  6. Latch assembly

    DOEpatents

    Frederickson, J.R.; Harper, W.H.; Perez, R.

    1984-08-17

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing. 2 figs.

  7. Sabot assembly

    DOEpatents

    Bzorgi, Fariborz

    2016-11-08

    A sabot assembly includes a projectile and a housing dimensioned and configured for receiving the projectile. An air pressure cavity having a cavity diameter is disposed between a front end and a rear end of the housing. Air intake nozzles are in fluid communication with the air pressure cavity and each has a nozzle diameter less than the cavity diameter. In operation, air flows through the plurality of air intake nozzles and into the air pressure cavity upon firing of the projectile from a gun barrel to pressurize the air pressure cavity for assisting in separation of the housing from the projectile upon the sabot assembly exiting the gun barrel.

  8. Latch assembly

    DOEpatents

    Frederickson, James R.; Harper, William H.; Perez, Raymond

    1986-01-01

    A latch assembly for releasably securing an article in the form of a canister within a container housing. The assembly includes a cam pivotally mounted on the housing wall and biased into the housing interior. The cam is urged into a disabled position by the canister as it enters the housing and a latch release plate maintains the cam disabled when the canister is properly seated in the housing. Upon displacement of the release plate, the cam snaps into latching engagement against the canister for securing the same within the housing.

  9. Genome Sequence Databases (Overview): Sequencing and Assembly

    SciTech Connect

    Lapidus, Alla L.

    2009-01-01

    From the date its role in heredity was discovered, DNA has been generating interest among scientists from different fields of knowledge: physicists have studied the three dimensional structure of the DNA molecule, biologists tried to decode the secrets of life hidden within these long molecules, and technologists invent and improve methods of DNA analysis. The analysis of the nucleotide sequence of DNA occupies a special place among the methods developed. Thanks to the variety of sequencing technologies available, the process of decoding the sequence of genomic DNA (or whole genome sequencing) has become robust and inexpensive. Meanwhile the assembly ofmore » whole genome sequences remains a challenging task. In addition to the need to assemble millions of DNA fragments of different length (from 35 bp (Solexa) to 800 bp (Sanger)), great interest in analysis of microbial communities (metagenomes) of different complexities raises new problems and pushes some new requirements for sequence assembly tools to the forefront. The genome assembly process can be divided into two steps: draft assembly and assembly improvement (finishing). Despite the fact that automatically performed assembly (or draft assembly) is capable of covering up to 98% of the genome, in most cases, it still contains incorrectly assembled reads. The error rate of the consensus sequence produced at this stage is about 1/2000 bp. A finished genome represents the genome assembly of much higher accuracy (with no gaps or incorrectly assembled areas) and quality ({approx}1 error/10,000 bp), validated through a number of computer and laboratory experiments.« less

  10. Method and apparatus for assembling permanent magnet rotors

    DOEpatents

    Hsu, J.S.; Adams, D.J.

    1999-06-22

    A permanent magnet assembly for assembly in large permanent magnet motors and generators includes a two-piece carrier that can be slid into a slot in the rotor and then secured in place using a set screw. The invention also provides an auxiliary carrier device with guide rails that line up with the teeth of the rotor, so that a permanent magnet assembly can be pushed first into a slot, and then down the slot to its proper location. An auxiliary tool is provided to move the permanent magnet assembly into position in the slot before it is secured in place. Methods of assembling and disassembling the magnet assemblies in the rotor are also disclosed. 2 figs.

  11. Method and apparatus for assembling permanent magnet rotors

    DOEpatents

    Hsu, John S.; Adams, Donald J.

    1999-01-01

    A permanent magnet assembly (22) for assembly in large permanent magnet (PM) motors and generators includes a two-piece carrier (23, 24) that can be slid into a slot (13) in the rotor (10) and then secured in place using a set screw (37). The invention also provides an auxiliary carrier device (50) with guide rails (51) that line up with the teeth (12) of the rotor, so that a permanent magnet assembly (22) can be pushed first into a slot (13), and then down the slot (13) to its proper location. An auxiliary tool (50) is provided to move the permanent magnet assembly (22) into position in the slot (13) before it is secured in place. Methods of assembling and disassembling the magnet assemblies (22) in the rotor (10) are also disclosed.

  12. NASA Green Propulsion Technologies Pushing Aviation to New Heights

    NASA Technical Reports Server (NTRS)

    Free, James M.; Jennings, Francis T.; Adanich, Emery; Del Rosario, Ruben; Felder, James L.

    2014-01-01

    Center Director Free is providing the Keynote at the Disruptive Propulsion Conference, sponsored by Cranfield University, Cranfield, Bedfordshire, England in November. Director Free will be presenting a PowerPoint presentation titled, NASA Green Propulsion Technologies Pushing Aviation to New Heights at both the conference and a meeting at the Royal Aeronautical Society.

  13. A Push-Button Electronic System to Promote Class Discussion.

    ERIC Educational Resources Information Center

    Uno, Gordon E.

    1984-01-01

    Describes a useful instrument designed to increase student participation and class discussion. Based on student response to the system while it was being used, student feedback, and personal experience, the push-button system installed in the laboratory was determined to be a success. (JN)

  14. Push-n-Go: A Dynamic Energy Conversion Lesson.

    ERIC Educational Resources Information Center

    Taylor, Beverly A. P.

    1998-01-01

    Focuses on the use of push and go toys to discuss with students how the toy acquires potential energy when work is done on it and how this energy is stored in the internal mechanism for later conversion into kinetic energy. (DDR)

  15. 33 CFR 83.24 - Towing and pushing (Rule 24).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

  16. 33 CFR 83.24 - Towing and pushing (Rule 24).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

  17. 33 CFR 83.24 - Towing and pushing (Rule 24).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

  18. 33 CFR 83.24 - Towing and pushing (Rule 24).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... line above the sternlight; and (5) When the length of the tow exceeds 200 meters, a diamond shape where... exceeds 200 meters, a diamond shape where it can best be seen. (f) Vessels being towed alongside or pushed... alongside each other shall be lighted as one vessel or object; (4) A diamond shape at or near the aftermost...

  19. Model Programs Compensatory Education: Project Early Push, Buffalo, New York.

    ERIC Educational Resources Information Center

    American Institutes for Research in the Behavioral Sciences, Palo Alto, CA.

    Part of a series of various Model Programs which informs educators about successful ongoing programs, the booklet describes the Project Early Push in Buffalo, New York, a preschool program for disadvantaged 4-year-olds which has been operating since 1966. The program provides experiences which are basic to later reading success and which are…

  20. Ring-push metric learning for person reidentification

    NASA Astrophysics Data System (ADS)

    He, Botao; Yu, Shaohua

    2017-05-01

    Person reidentification (re-id) has been widely studied because of its extensive use in video surveillance and forensics applications. It aims to search a specific person among a nonoverlapping camera network, which is highly challenging due to large variations in the cluttered background, human pose, and camera viewpoint. We present a metric learning algorithm for learning a Mahalanobis distance for re-id. Generally speaking, there exist two forces in the conventional metric learning process, one pulling force that pulls points of the same class closer and the other pushing force that pushes points of different classes as far apart as possible. We argue that, when only a limited number of training data are given, forcing interclass distances to be as large as possible may drive the metric to overfit the uninformative part of the images, such as noises and backgrounds. To alleviate overfitting, we propose the ring-push metric learning algorithm. Different from other metric learning methods that only punish too small interclass distances, in the proposed method, both too small and too large inter-class distances are punished. By introducing the generalized logistic function as the loss, we formulate the ring-push metric learning as a convex optimization problem and utilize the projected gradient descent method to solve it. The experimental results on four public datasets demonstrate the effectiveness of the proposed algorithm.

  1. PNNL pushing scientific discovery through data intensive computing breakthroughs

    ScienceCinema

    Deborah Gracio; David Koppenaal; Ruby Leung

    2017-12-09

    The Pacific Northwest National Laboratorys approach to data intensive computing (DIC) is focused on three key research areas: hybrid hardware architectures, software architectures, and analytic algorithms. Advancements in these areas will help to address, and solve, DIC issues associated with capturing, managing, analyzing and understanding, in near real time, data at volumes and rates that push the frontiers of current technologies.

  2. NSF Anticipates Pushing Boundaries on Open-Access Plan

    ERIC Educational Resources Information Center

    Basken, Paul

    2013-01-01

    The National Science Foundation (NSF), in carrying out the Obama administration's new push for greater public access to research published in scientific journals, will consider exclusivity periods shorter than the 12-month standard in the White House directive, as well as trade-offs involving data-sharing and considerations of publishers'…

  3. Preemptive queueing system with randomized push-out mechanism

    NASA Astrophysics Data System (ADS)

    Muliukha, Vladimir; Ilyashenko, Alexander; Zayats, Oleg; Zaborovsky, Vladimir

    2015-04-01

    In this article considered a queueing theory model with limited buffer size, one service channel, and two incoming flows. In this model one of the flows has a power to preempt other tasks. We call it a high-priority flow. Another one is low-priority. This priority mechanism is realized in a two different ways. The first one is a preemptive priority, which allows high-priority packets to interrupt low-priority packets in service channel and push them out. The second one is a randomized push-out mechanism with probability α, which allows us to choose what type of packets should be pushed out of the system when it is full. In this article we provide an algorithm for computing statistical characteristics of the model for all values of push-out probability α. We have used generating functions method to simplify the system of linear equations. This method allows us to reduce the order of linear equations system from k(k + 1)/2 to (k + 1). As the result we have got two effects in this model. The first one is a linear behavior of loss probabilities in the model with low overload. The second one is a "closing" of a system for low-priority packets with high overload.

  4. Furnace assembly

    DOEpatents

    Panayotou, Nicholas F.; Green, Donald R.; Price, Larry S.

    1985-01-01

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  5. Furnace assembly

    DOEpatents

    Panayotou, N.F.; Green, D.R.; Price, L.S.

    A method of and apparatus for heating test specimens to desired elevated temperatures for irradiation by a high energy neutron source. A furnace assembly is provided for heating two separate groups of specimens to substantially different, elevated, isothermal temperatures in a high vacuum environment while positioning the two specimen groups symmetrically at equivalent neutron irradiating positions.

  6. Push-out Bond Strength of Injectable Pozzolan-based Root Canal Sealer.

    PubMed

    Silva, Emmanuel João Nogueira Leal; Carvalho, Nancy Kudsi; Prado, Marina C; Zanon, Mayara; Senna, Plinio Mendes; Souza, Erick M; De-Deus, Gustavo

    2016-11-01

    The present study aimed to rank the bond strength to root dentin of a new injectable pozzolan-based root canal sealer, EndoSeal MTA, as compared with MTA Fillapex and AH Plus. Eighteen dentinal slices (1 ± 0.1 mm) were obtained from the middle third of 6 maxillary incisors previously selected. Three canal-like holes with 0.8 mm diameter were drilled perpendicularly on the axial surface of each slice. Then, a standardized irrigation was applied for all holes that were subsequently filled with 1 of 3 test root canal sealers. After that, slices were stored in contact with phosphate-buffered saline solution (pH 7.2) for 7 days at 37°C before the push-out assay. Friedman test and Wilcoxon signed rank test with a Bonferroni correction were used to rank the results. Significance boundary was set at α = 5%. Friedman test confirmed a significant dissimilarity in push-out ranks among the tested cements (P < .01). Wilcoxon signed rank test demonstrated AH Plus had significant superior resistance to dislodgment compared with Endo Seal (P < .01) or MTA Fillapex (P < .01), whereas MTA Fillapex presented the lowest push-out values as compared with Endo Seal (P < .01) or AH Plus (P < .01). EndoSeal presents satisfactory bond strength performance for application in endodontic therapy compared with MTA Fillapex, and although it displays a new alternative of injectable bio-tight root canal sealer, it is not able to improve adhesion compared with AH Plus. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Predicting Bobsled Pushing Ability from Various Combine Testing Events.

    PubMed

    Tomasevicz, Curtis L; Ransone, Jack W; Bach, Christopher W

    2018-03-12

    The requisite combination of speed, power, and strength necessary for a bobsled push athlete coupled with the difficulty in directly measuring pushing ability makes selecting effective push crews challenging. Current practices by USA Bobsled and Skeleton (USABS) utilize field combine testing to assess and identify specifically selected performance variables in an attempt to best predict push performance abilities. Combine data consisting of 11 physical performance variables were collected from 75 subjects across two winter Olympic qualification years (2009 and 2013). These variables were sprints of 15-, 30-, and 60 m, a flying 30 m sprint, a standing broad jump, a shot toss, squat, power clean, body mass, and dry-land brake and side bobsled pushes. Discriminant Analysis (DA) in addition to Principle Component Analysis (PCA) was used to investigate two cases (Case 1: Olympians vs. non-Olympians; Case 2: National Team vs. non-National Team). Using these 11 variables, DA led to a classification rule that proved capable of identifying Olympians from non-Olympians and National Team members from non-National Team members with 9.33% and 14.67% misclassification rates, respectively. The PCA was used to find similar test variables within the combine that provided redundant or useless data. After eliminating the unnecessary variables, DA on the new combinations showed that 8 (Case 1) and 20 (Case 2) other combinations with fewer performance variables yielded misclassification rates as low as 6.67% and 13.33% respectively. Utilizing fewer performance variables can allow governing bodies in many other sports to create more appropriate combine testing that maximize accuracy, while minimizing irrelevant and redundant strategies.

  8. Large-Scale CTRW Analysis of Push-Pull Tracer Tests and Other Transport in Heterogeneous Porous Media

    NASA Astrophysics Data System (ADS)

    Hansen, S. K.; Berkowitz, B.

    2014-12-01

    Recently, we developed an alternative CTRW formulation which uses a "latching" upscaling scheme to rigorously map continuous or fine-scale stochastic solute motion onto discrete transitions on an arbitrarily coarse lattice (with spacing potentially on the meter scale or more). This approach enables model simplification, among many other things. Under advection, for example, we see that many relevant anomalous transport problems may be mapped into 1D, with latching to a sequence of successive, uniformly spaced planes. On this formulation (which we term RP-CTRW), the spatial transition vector may generally be made deterministic, with CTRW waiting time distributions encapsulating all the stochastic behavior. We demonstrate the excellent performance of this technique alongside Pareto-distributed waiting times in explaining experiments across a variety of scales using only two degrees of freedom. An interesting new application of the RP-CTRW technique is the analysis of radial (push-pull) tracer tests. Given modern computational power, random walk simulations are a natural fit for the inverse problem of inferring subsurface parameters from push-pull test data, and we propose them as an alternative to the classical type curve approach. In particular, we explore the visibility of heterogeneity through non-Fickian behavior in push-pull tests, and illustrate the ability of a radial RP-CTRW technique to encapsulate this behavior using a sparse parameterization which has predictive value.

  9. Electromyography of 3 scapular muscles: a comparative analysis of the cuff link device and a standard push-up.

    PubMed

    Tucker, W Steven; Campbell, Brian M; Swartz, Erik E; Armstrong, Charles W

    2008-01-01

    participant failure rate. Because serratus anterior activation levels were similar, the Cuff Link may be an appropriate alternative for individuals lacking the upper body strength to perform a push-up.

  10. Electromyography of 3 Scapular Muscles: A Comparative Analysis of The Cuff Link Device and a Standard Push-Up

    PubMed Central

    Tucker, W Steven; Campbell, Brian M; Swartz, Erik E; Armstrong, Charles W

    2008-01-01

    . Conclusions: The push-up demonstrated greater middle trapezius and lower trapezius activation levels compared with the Cuff Link. However, the push-up had a high participant failure rate. Because serratus anterior activation levels were similar, the Cuff Link may be an appropriate alternative for individuals lacking the upper body strength to perform a push-up. PMID:18833308

  11. Mechanical seal assembly

    DOEpatents

    Kotlyar, Oleg M.

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  12. Mechanical seal assembly

    DOEpatents

    Kotlyar, Oleg M.

    2002-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transfering it to the mechanical diode.

  13. An unstable support surface does not increase scapulothoracic stabilizing muscle activity during push up and push up plus exercises.

    PubMed

    Lehman, Gregory J; Gilas, Danielle; Patel, Ushma

    2008-12-01

    The aim of the current study is to determine if performing push up exercise variations on an unstable surface (Swiss ball) influences EMG amplitude of the scapulothoracic muscles when compared with a stable surface (Bench). Ten males were recruited from a convenience sample of college students. Surface electromyograms were recorded from the upper trapezius, lower trapezius, serratus anterior and biceps brachii while performing push up exercises with the feet or hands placed on a bench and separately on a Swiss ball. A push up plus exercise was also evaluated with hands on the different support surfaces. There was no statistically significant (p<0.05) difference in mean EMG amplitude on a Swiss ball when compared with the same exercise performed on a bench. Significant differences in muscle activity were seen in the upper trapezius and serratus anterior as a result of changes in foot position relative to hand position irrespective of surface stability. The unstable surface used in this study is not a sufficient condition to generate an increase in muscle activity in select scapulothoracic and glenohumeral muscles during push up exercise variations. Elevating the feet above the hands appeared to have a greater influence on shoulder stabilizing musculature amplitude than the addition of a Swiss ball.

  14. Sensor assembly

    DOEpatents

    Bennett, Thomas E.; Nelson, Drew V.

    2004-04-13

    A ribbon-like sensor assembly is described wherein a length of an optical fiber embedded within a similar lengths of a prepreg tow. The fiber is ""sandwiched"" by two layers of the prepreg tow which are merged to form a single consolidated ribbon. The consolidated ribbon achieving a generally uniform distribution of composite filaments near the embedded fiber such that excess resin does not ""pool"" around the periphery of the embedded fiber.

  15. Biomechanical analysis for handle stability during maximum push and pull exertions.

    PubMed

    Seo, Na Jin; Armstrong, Thomas J

    2009-12-01

    This study investigated the effect of handle stability on maximum push/pull force. It was hypothesised that people apply force in directions deviated from the pure push/pull direction to generate a moment that assists producing greater push/pull force when the handle position is fixed (stable) compared to when it is not fixed (unstable). Eight healthy subjects performed maximum push and pull exertions on a stable and an unstable handle in a seated posture, while maximum push/pull force, vertical force and lateral force were recorded. For the unstable handle, vertical and lateral forces were not different from zero during push and pull. For the stable handle, subjects intuitively applied significant downward force during push and significant upward force during pull exertions. As predicted from biomechanical analysis, this downward and upward force was found to be significantly associated with increased push and pull force, respectively, for the stable handle compared to the unstable handle.

  16. Synthesis of novel push-pull unsymmetrically substituted alkynyl phthalocyanines

    PubMed

    Maya; Garcia; Garcia-Frutos; Vazquez; Torres

    2000-05-09

    Two families of "push-pull" phthalocyanines 1-3 having an unusually strong dipole moment have been prepared. The syntheses of unsymmetrically substituted phthalocyanines 1a,b and 2 bearing one or two electron-withdrawing 4-nitrophenylethynyl moieties, respectively, and six alkoxy substituents were performed by combination of a zinc or nickel templated cyclotetramerization and cross-coupling palladium mediated methodologies. In a similar way, the "push-pull" compounds 3a,b having a reversal substitution pattern, characterized by the presence of one electron-donor 4-(dimethylamino)phenylethynyl unit and six strong acceptor alkylsulfonyl substituents were prepared. The compounds show very large second-order nonlinear optical responses.

  17. Marine ice-pushed boulder ridge, Beaufort Sea, Alaska

    USGS Publications Warehouse

    Barnes, Peter W.

    1982-01-01

    A steep-faced boulder ridge up to 4m high by 300m long was encountered along the arctic coast east of Prudhoe Bay, Alaska, in the summer of 1979. Marine occurrences of similar ridges are rare. Since ice-push sorts cobble- and boulder-sized material in the construction of a ridge, recent onshore excursions of ice due to wind stress on the fast ice are believed to be responsible for building the boulder ridge. Ice push is a mechanism that preferentially sorts cobble- and boulder-sized material from 1-2m water depths and that forms boulder ridges in areas of high boulder concentrations.

  18. Foot forces induced through Tai Chi push-hand exercises.

    PubMed

    Wong, Shiu Hong; Ji, Tianjian; Hong, Youlian; Fok, Siu Lun; Wang, Lin

    2013-08-01

    The low impact forces of Tai Chi push-hand exercises may be particularly suited for older people and for those with arthritis; however, the biomechanics of push-hand exercises have not previously been reported. This paper examines the ground reaction forces (GRFs) and plantar force distributions during Tai Chi push-hand exercises in a stationary stance with and without an opponent. Ten male Tai Chi practitioners participated in the study. The GRFs of each foot were measured in three perpendicular directions using two force plates (Kistler). The plantar force distribution of each foot was measured concurrently using an insole sensor system (Novel). The results showed that the average maximum vertical GRF of each foot was not more than 88% ± 6.1% of the body weight and the sum of the vertical forces (103% ± 1.4%) generated by the two feet approximately equals the body weight at any one time. The horizontal GRFs generated by the two feet were in the opposite directions and the measured mean peak values were not more than 12% ± 2.8% and 17% ± 4.3% of the body weight in the medio-lateral and antero-posterior directions respectively. Among the nine plantar areas, the toes sustained the greatest plantar force. This study indicates that push-hand exercises generate lower vertical forces than those induced by walking, bouncing, jumping and Tai Chi gait, and that the greatest plantar force is located in the toe area, which may have an important application in balance training particularly for older adults.

  19. Fiber-optic push-pull sensor systems

    NASA Technical Reports Server (NTRS)

    Gardner, David L.; Brown, David A.; Garrett, Steven L.

    1991-01-01

    Fiber-optic push-pull sensors are those which exploit the intrinsically differential nature of an interferometer with concommitant benefits in common-mode rejection of undesired effects. Several fiber-optic accelerometer and hydrophone designs are described. Additionally, the recent development at the Naval Postgraduate School of a passive low-cost interferometric signal demodulator permits the development of economical fiber-optic sensor systems.

  20. How to push a block along a wall

    NASA Technical Reports Server (NTRS)

    Mason, Matthew T.

    1989-01-01

    Some robot tasks require manipulation of objects that may be touching other fixed objects. The effects of friction and kinematic constraint must be anticipated, and may even be exploited to accomplish the task. An example task, a dynamic analysis, and appropriate effector motions are presented. The goal is to move a rectangular block along a wall, so that one side of the block maintains contact with the wall. Two solutions that push the block along the wall are discussed.

  1. Nonplanar push-pull chromophores for opto-electronic applications.

    PubMed

    Breiten, Benjamin; Biaggio, Ivan; Diederich, François

    2010-01-01

    Donor-substituted cyanoethynylethenes (CEEs) are planar push-pull chromophores featuring intense intramolecular charge-transfer (CT) interactions and high third-order optical nonlinearities. Their thermal stability allows for the formation of crystalline thin films by vapor-phase deposition. On the other hand, high-quality amorphous thin films are preferred for opto-electronic applications and such films can be prepared using nonplanar push-pull chromophores with a less pronounced propensity to crystallize. By taking advantage of a versatile, atom-economic 'click-chemistry'-type transformation, involving a formal [2 + 2] cycloaddition of tetracyanoethene (TCNE) to electron-rich alkynes, followed by cycloreversion, stable donor-substituted 1,1,4,4-tetracyanobuta-1,3-dienes (TCBDs) are obtained in high yield and large quantities. These nonplanar push-pull chromophores also feature intense intramolecular CT and, in many cases, high third-order optical nonlinearities. Some of these compounds form high-optical-quality amorphous thin films by vapor-phase deposition, and first applications in next-generation opto-electronic devices have already been demonstrated. Chiral derivatives display high helical twisting power and are efficient dopants to translate molecular into macroscopic chirality, by switching nematic into cholesteric liquid crystalline phases.

  2. Validation of a biodynamic model of pushing and pulling.

    PubMed

    Andres, R O; Chaffin, D B

    1991-01-01

    Pushing and pulling during manual material handling can increase the compressive forces on the lumbar disc region while creating high shear forces at the shoe-floor interface. A sagittal plane dynamic model derived from previous biomechanical models was developed to predict L5/S1 compressive force and required coefficients of friction during dynamic cart pushing and pulling. Before these predictions could be interpreted, however, it was necessary to validate model predictions against independently measured values of comparable quantities. This experiment used subjects of disparate stature and body mass, while task factors such as cart resistance and walking speed were varied. Predicted ground reaction forces were compared with those measured by a force platform, with correlations up to 0.67. Predicted erector spinae and rectus abdominus muscle forces were compared with muscle forces derived from RMS-EMGs of the respective muscle groups, using a static force build-up regression relationship to transform the dynamic RMS-EMGs to trunk muscle forces. Although correlations were low, this was attributed in part to the use of surface EMG on subjects of widely varied body mass. The biodynamic model holds promise as a tool for analysis of actual industrial pushing and pulling tasks, when carefully applied.

  3. Modeling and Simulation of Two Wheelchair Accessories for Pushing Doors.

    PubMed

    Abdullah, Soran Jalal; Shaikh Mohammed, Javeed

    2017-03-27

    Independent mobility is vital to individuals of all ages, and wheelchairs have proven to be great personal mobility devices. The tasks of opening and navigating through a door are trivial for healthy people, while the same tasks could be difficult for some wheelchair users. A wide range of intelligent wheelchair controllers and systems, robotic arms, or manipulator attachments integrated with wheelchairs have been developed for various applications, including manipulating door knobs. Unfortunately, the intelligent wheelchairs and robotic attachments are not widely available as commercial products. Therefore, the current manuscript presents the modeling and simulation of a novel but simple technology in the form of a passive wheelchair accessory (straight, arm-like with a single wheel, and arc-shaped with multiple wheels) for pushing doors open from a wheelchair. From the simulations using different wheel shapes and sizes, it was found that the arc-shaped accessory could push open the doors faster and with almost half the required force as compared to the arm-like accessory. Also, smaller spherical wheels were found to be best in terms of reaction forces on the wheels. Prototypes based on the arc-shaped accessory design will be manufactured and evaluated for pushing doors open and dodging or gliding other obstacles.

  4. Alternative security

    SciTech Connect

    Weston, B.H.

    1990-01-01

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview.

  5. Manual handling: differences in perceived effort, success rate and kinematics between three different pushing techniques.

    PubMed

    Varcin, Lynn; Claus, Andrew; van den Hoorn, Wolbert; Hodges, Paul

    2015-01-01

    This study examined the perceived effort, success rates and kinematics for three push strategies in a simulated lateral patient transfer (horizontal slide). Thirteen healthy subjects (four males) completed three repetition pushing loads of 6, 10 and 14 kg in random order; with a spontaneous push strategy, then with a straight-back bent-knees (squat) strategy and the preparatory pelvic movement ('rockback') strategy in random order. Perceived effort and kinematic parameters measured at the onset of movement and at maximum push excursion were compared between strategies and between loads with repeated measures ANOVA. The spontaneous and 'rockback' strategies achieved the pushing task with less perceived effort across all loads than the squat push (P < 0.001). Only 3/13 participants were successful on all attempts at pushing the 14 kg load using a squat strategy, which contrasted with 12/13 participants when the spontaneous strategy or the 'rockback' strategy was used. Forward movement of the pelvis and forward trunk inclination may be positively associated with lower perceived effort in the push task. Practitioner Summary: In a manual-handling task that simulated a lateral patient transfer (horizontal slide), perceived effort and success rates of three push strategies were compared. A straight-back bent-knees push (squat) strategy demonstrated greater perceived effort and lower success rates than a spontaneous push strategy, or a push strategy with preparatory 'rockback' pelvic movement.

  6. Pushrod assembly

    DOEpatents

    Potter, J.D.

    1984-03-30

    A pushrod assembly including a carriage mounted on a shaft for movement therealong and carrying a pushrod engageable with a load to be moved is described. A magnet is mounted on a supporting bracket for movement along such shaft. Means are provided for adjustably spacing magnet away from the carriage to obtain a selected magnetic attractive or coupling force therebetween. Movement of the supporting bracket and the magnet carried thereby pulls the carriage along with it until the selected magnetic force is exceeded by a resistance load acting on the carriage.

  7. Pushrod assembly

    DOEpatents

    Potter, Jerry D.

    1987-01-01

    A pushrod assembly including a carriage mounted on a shaft for movement therealong and carrying a pushrod engageable with a load to be moved. A magnet is mounted on a supporting bracket for movement along such shaft. Means are provided for adjustably spacing said magnet away from said carriage to obtain a selected magnetic attractive or coupling force therebetween. Movement of the supporting bracket and the magnet carried thereby pulls the carriage along with it until the selected magnetic force is exceeded by a resistance load acting on the carriage.

  8. Shingle assembly

    DOEpatents

    Dinwoodie, Thomas L.

    2007-02-20

    A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. The first edge of one base may be interengageable with the second edge of an adjacent base to be capable of resisting first and second disengaging forces oriented perpendicular to the edges and along planes oriented parallel to and perpendicular to the base. A deflector may be used to help reduce wind uplift forces.

  9. Dump assembly

    DOEpatents

    Goldmann, L.H.

    1984-12-06

    This is a claim for a dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough. 4 figs.

  10. Effect of External Loading on Force and Power Production During Plyometric Push-ups.

    PubMed

    Hinshaw, Taylour J; Stephenson, Mitchell L; Sha, Zhanxin; Dai, Boyi

    2018-04-01

    Hinshaw, TJ, Stephenson, ML, Sha, Z, and Dai, B. Effect of external loading on force and power production during plyometric push-ups. J Strength Cond Res 32(4): 1099-1108, 2018-One common exercise to train upper-body strength and power is the push-up. Training at the loads that would produce the greatest power is an effective way to increase peak power. The purpose of the current study was to quantify the changes in peak force, peak power, and peak velocity among a modified plyometric push-up and plyometric push-ups with or without external loading in physically active young adults. Eighteen male and 17 female participants completed 4 push-ups: (a) modified plyometric push-up on the knees, (b) plyometric push-up without external loading, (c) plyometric push-up with an external load of 5% of body weight, and (d) plyometric push-up with an external load of 10% of body weight. Two force platforms were set up to collect vertical ground reaction forces at the hands and feet. The modified plyometric push-up demonstrated the lowest force, power, and velocity (5.4≥ Cohen's dz ≥1.2). Peak force and force at peak velocity increased (3.8≥ Cohen's dz ≥0.3) and peak velocity and velocity at peak power decreased (1.4≥ Cohen's dz ≥0.8) for the push-up without external loading compared with the 2 push-ups with external loading. No significant differences were observed for peak power among the push-ups with or without external loading (0.4≥ Cohen's dz ≥0.1). Although peak power is similar with or without external loading, push-ups without external loading may be more beneficial for a quick movement, and push-ups with external loading may be more beneficial for a greater force production.

  11. Psychophysical basis for maximum pushing and pulling forces: A review and recommendations

    PubMed Central

    Garg, Arun; Waters, Thomas; Kapellusch, Jay; Karwowski, Waldemar

    2015-01-01

    The objective of this paper was to perform a comprehensive review of psychophysically determined maximum acceptable pushing and pulling forces. Factors affecting pushing and pulling forces are identified and discussed. Recent studies show a significant decrease (compared to previous studies) in maximum acceptable forces for males but not for females when pushing and pulling on a treadmill. A comparison of pushing and pulling forces measured using a high inertia cart with those measured on a treadmill shows that the pushing and pulling forces using high inertia cart are higher for males but are about the same for females. It is concluded that the recommendations of Snook and Ciriello (1991) for pushing and pulling forces are still valid and provide reasonable recommendations for ergonomics practitioners. Regression equations as a function of handle height, frequency of exertion and pushing/pulling distance are provided to estimate maximum initial and sustained forces for pushing and pulling acceptable to 75% male and female workers. At present it is not clear whether pushing or pulling should be favored. Similarly, it is not clear what handle heights would be optimal for pushing and pulling. Epidemiological studies are needed to determine relationships between psychophysically determined maximum acceptable pushing and pulling forces and risk of musculoskeletal injuries, in particular to low back and shoulders. PMID:26664045

  12. An electromyographical analysis of the scapular stabilizing synergists during a push-up progression.

    PubMed

    Lear, L J; Gross, M T

    1998-09-01

    Current literature recommends incorporating push-up progressions into upper extremity rehabilitation for advanced training of the scapular stabilizers. No documentation exists to demonstrate changes in the level of muscle activation when push-up progressions are performed. The purpose of this study was to determine the effect of difficulty level for push-ups on electrical activity of the scapular stabilizing synergists. Sixteen subjects performed five repetitions for each of the three conditions in a push-up progression. Electromyographic data collected on the serratus anterior, upper trapezius, and lower trapezius revealed a statistically significant interaction effect between the serratus anterior and upper trapezius and push-up condition when the feet were elevated. No significant interaction was found between push-up condition and the lower trapezius. This study supports the clinical use of push-up progressions to facilitate activation of the serratus anterior and the upper trapezius during upper extremity rehabilitation.

  13. Swivel assembly

    DOEpatents

    Hall, David R.; Pixton, David S.; Briscoe, Michael; Bradford, Kline; Rawle, Michael; Bartholomew, David B.; McPherson, James

    2007-03-20

    A swivel assembly for a downhole tool string comprises a first and second coaxial housing cooperatively arranged. The first housing comprises a first transmission element in communication with surface equipment. The second housing comprises a second transmission element in communication with the first transmission element. The second housing further comprises a third transmission element adapted for communication with a network integrated into the downhole tool string. The second housing may be rotational and adapted to transmit a signal between the downhole network and the first housing. Electronic circuitry is in communication with at least one of the transmission elements. The electronic circuitry may be externally mounted to the first or second housing. Further, the electronic circuitry may be internally mounted in the second housing. The electronic circuitry may be disposed in a recess in either first or second housing of the swivel.

  14. Thermocouple assembly

    DOEpatents

    Thermos, Anthony Constantine; Rahal, Fadi Elias

    2002-01-01

    A thermocouple assembly includes a thermocouple; a plurality of lead wires extending from the thermocouple; an insulating jacket extending along and enclosing the plurality of leads; and at least one internally sealed area within the insulating jacket to prevent fluid leakage along and within the insulating jacket. The invention also provides a method of preventing leakage of a fluid along and through an insulating jacket of a thermocouple including the steps of a) attaching a plurality of lead wires to a thermocouple; b) adding a heat sensitive pseudo-wire to extend along the plurality of lead wires; c) enclosing the lead wires and pseudo-wire inside an insulating jacket; d) locally heating axially spaced portions of the insulating jacket to a temperature which melts the pseudo-wire and fuses it with an interior surface of the jacket.

  15. RETORT ASSEMBLY

    DOEpatents

    Loomis, C.C.; Ash, W.J.

    1957-11-26

    An improved retort assembly useful in the thermal reduction of volatilizable metals such as magnesium and calcium is described. In this process a high vacuum is maintained in the retort, however the retort must be heated to very high temperatures while at the same time the unloading end must bo cooled to condense the metal vapors, therefore the retention of the vacuum is frequently difficult due to the thermal stresses involved. This apparatus provides an extended condenser sleeve enclosed by the retort cover which forms the vacuum seal. Therefore, the seal is cooled by the fluid in the condenser sleeve and the extreme thermal stresses found in previous designs together with the deterioration of the sealing gasket caused by the high temperatures are avoided.

  16. Self-assembled biomimetic nanoreactors I: Polymeric template

    NASA Astrophysics Data System (ADS)

    McTaggart, Matt; Malardier-Jugroot, Cecile; Jugroot, Manish

    2015-09-01

    The variety of nanoarchitectures made feasible by the self-assembly of alternating copolymers opens new avenues for biomimicry. Indeed, self-assembled structures allow the development of nanoreactors which combine the efficiency of high surface area metal active centres to the effect of confinement due to the very small cavities generated by the self-assembly process. A novel self-assembly of high molecular weight alternating copolymers is characterized in the present study. The self-assembly is shown to organize into nanosheets, providing a 2 nm hydrophobic cavity with a 1D confinement.

  17. Road user fee task force report to the 72nd Oregon Legislative Assembly on the possible alternatives of the current system of taxing highway use through motor vehicle fuel taxes

    DOT National Transportation Integrated Search

    2003-03-01

    Recognizing that the fuel tax is a declining revenue source for Oregon's road system, the 2001 Oregon Legislative Assembly passed House Bill 3946, mandating the formation of the Road User Fee Task Force with the mission to develop a design for revenu...

  18. Stress fracture of ulna due to excessive push-ups.

    PubMed

    Meena, Sanjay; Rastogi, Devarshi; Solanki, Bipin; Chowdhury, Buddhadev

    2014-01-01

    Stress fractures are most common in the weight-bearing bones of the lower extremities and spine, but are rarely found in non-weight-bearing bones of the body. Stress fracture of the ulna is extremely rare. We report a case of complete stress fracture of ulna caused due to excessive push ups in a young athlete. Conservative management was successful in healing of fracture and returning this patient back to his previous activity level. Physician should have high index of suspicion, whenever they encounter a young athlete complaining of forearm pain.

  19. Stress fracture of ulna due to excessive push-ups

    PubMed Central

    Meena, Sanjay; Rastogi, Devarshi; Solanki, Bipin; Chowdhury, Buddhadev

    2014-01-01

    Stress fractures are most common in the weight-bearing bones of the lower extremities and spine, but are rarely found in non-weight-bearing bones of the body. Stress fracture of the ulna is extremely rare. We report a case of complete stress fracture of ulna caused due to excessive push ups in a young athlete. Conservative management was successful in healing of fracture and returning this patient back to his previous activity level. Physician should have high index of suspicion, whenever they encounter a young athlete complaining of forearm pain. PMID:24678236

  20. Text Content Pushing Technology Research Based on Location and Topic

    NASA Astrophysics Data System (ADS)

    Wei, Dongqi; Wei, Jianxin; Wumuti, Naheman; Jiang, Baode

    2016-11-01

    In the field, geological workers usually want to obtain related geological background information in the working area quickly and accurately. This information exists in the massive geological data, text data is described in natural language accounted for a large proportion. This paper studied location information extracting method in the mass text data; proposed a geographic location—geological content—geological content related algorithm based on Spark and Mapreduce2, finally classified content by using KNN, and built the content pushing system based on location and topic. It is running in the geological survey cloud, and we have gained a good effect in testing by using real geological data.

  1. A high-sensitivity push-pull magnetometer

    SciTech Connect

    Breschi, E.; Grujić, Z. D.; Knowles, P.

    2014-01-13

    We describe our approach to atomic magnetometry based on the push-pull optical pumping technique. Cesium vapor is pumped and probed by a resonant laser beam whose circular polarization is modulated synchronously with the spin evolution dynamics induced by a static magnetic field. The magnetometer is operated in a phase-locked loop, and it has an intrinsic sensitivity below 20fT/√(Hz), using a room temperature paraffin-coated cell. We use the magnetometer to monitor magnetic field fluctuations with a sensitivity of 300fT/√(Hz)

  2. In Situ Determination of Sulfate Reduction in Peatlands - A Downscaled Push-Pull Tracer Technique

    NASA Astrophysics Data System (ADS)

    Goldhammer, T.; Blodau, C.

    2005-12-01

    Microbial dissimilatory sulfate reduction is a key process for carbon cycling in nutrient-poor peatlands. For an estimation of a future behaviour of these carbon-rich ecosystems under altered environmental conditions, reliable methods for a quantification of biogeochemical processes still have to be developed. In general, sulfate reduction is being quantified via laboratory-scale incubation experiments with field samples. A main disadvantage and source of uncertainty of this approach is the use of disturbed samples and the determination of not actual but potential turnover rates, which can not easily be extrapolated to the field scale. In order to find an alternative for measuring sulfate reduction in peat soils we developed an experimental design derived from hydrogeological practice, where single-well push-pull tracer tests are widely used for in situ determination of microbial activities in aquifers. A mixture of a conservative tracer and a reactant is injected into a well and regained after a certain time of in situ incubation. Assuming that sulfate reduction follows mainly first-order reaction kinetics, the analysis of the obtained breakthrough curve data is simple. The slope of a log-linear regression of the ratio of relative reactant vs. tracer concentrations plotted against time since injection delivers the reaction rate coefficient k. Nine piezometers installed at three depth levels (20-30, 30-40 and 50-60cm below ground surface) in Mer Bleue Bog, Ontario, Canada were used to conduct three series of push-pull tracer tests. In both uppermost depth-levels, increased hydraulic conductivity causes a dominance of lateral flow and leads to lower recovery rates. Nevertheless, with restrictions due to a higher sensitivity to operational errors, data from these replicates could be used for method evaluation. Mean k values ranged from -7.2*10-3 to -11.7*10-3 h-1. Positive k values representing increasing sulfate concentrations were determined in several series of

  3. The blind pushing technique for peripherally inserted central catheter placement through brachial vein puncture.

    PubMed

    Lee, Jae Myeong; Cho, Young Kwon; Kim, Han Myun; Song, Myung Gyu; Song, Soon-Young; Yeon, Jae Woo; Yoon, Dae Young; Lee, Sam Yeol

    2018-03-01

    nonbrachial vein access in the incidence of UEDVT (odds ratio, 0.68; 95% confidence interval, 0.59-3.52; P = .22). The placement of pretrimmed PICCs by the blind pushing technique and primary brachial vein access is technically feasible and may represent an alternative to the conventional PICC placement technique, having low incidences of UEDVT and other complications, with no significant difference in outcomes between brachial vein and nonbrachial vein access. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  4. Crankshaft position sensing with combined starter alternator

    DOEpatents

    Brandenburg, Larry Raymond; Miller, John Michael

    2000-06-13

    A crankshaft position sensing apparatus for use with an engine (16) having a combined starter/alternator assembly (18). The crankshaft position sensing apparatus includes a tone ring (38) with a sensor (36) and bandpass filter (46), having a cylinder identification input from a camshaft sensor (48), and a gain limiter (54). The sensing apparatus mounts near the rotor (30) of the combined starter/alternator assembly (18). The filtered crankshaft position signal can then be input into a vehicle system controller (58) and an inner loop controller (60). The starter/alternator assembly (18) in combination with an internal combustion engine is particularly useful for a hybrid electric vehicle system.

  5. Simulation of push-pull inverter using wide bandgap devices

    NASA Astrophysics Data System (ADS)

    Al-badri, Mustafa; Matin, Mohammed A.

    2016-09-01

    This paper discusses the use of wide bandgap devices (SiC-MOSFET) in the design of a push-pull inverter which provides inexpensive low power dc-ac inverters. The parameters used were 1200V SiC MOSFET(C2M0040120D) made by power company ROHM. This modeling was created using parameters that were provided from a device datasheet. The spice model is provided by this company to study the effect of adding this component on push-pull inverter ordinary circuit and compared results between SiC MOSFET and silicon MOSFET (IRFP260M). The results focused on Vout and Vmos stability as well as on output power and MOSFET power loss because it is a very crucial aspect on DC-AC inverter design. These results are done using the National Instrument simulation program (Multisim 14). It was found that power loss is better in the 12 and 15 vdc inverter. The Vout in the SIC MOSFET circuit shows more stability in the high current low resistance load in comparison to the Silicon MOSFET circuit and this will improve the overall performance of the circuit.

  6. Characterizing hydraulic conductivity with the direct-push permeameter

    USGS Publications Warehouse

    Butler, J.J.; Dietrich, P.; Wittig, V.; Christy, T.

    2007-01-01

    The direct-push permeameter (DPP) is a promising approach for obtaining high-resolution information about vertical variations in hydraulic conductivity (K) in shallow unconsolidated settings. This small-diameter tool, which consists of a short screened section with a pair of transducers inset in the tool near the screen, is pushed into the subsurface to a depth at which a K estimate is desired. A short hydraulic test is then performed by injecting water through the screen at a constant rate (less than 4 L/min) while pressure changes are monitored at the transducer locations. Hydraulic conductivity is calculated using the injection rate and the pressure changes in simple expressions based on Darcy's Law. In units of moderate or higher hydraulic conductivity (more than 1 m/d), testing at a single level can be completed within 10 to 15 min. Two major advantages of the method are its speed and the insensitivity of the K estimates to the zone of compaction created by tool advancement. The potential of the approach has been assessed at two extensively studied sites in the United States and Germany over a K range commonly faced in practical field investigations (0.02 to 500 m/d). The results of this assessment demonstrate that the DPP can provide high-resolution K estimates that are in good agreement with estimates obtained through other means. ?? 2007 National Ground Water Association.

  7. Reduction of discomfort in pushing an industrial trolley using ergonomics

    NASA Astrophysics Data System (ADS)

    Kumar, M. Wilson; Vijay, S. J.; Vasudev, K. L.; Darius Gnanaraj, S.

    2017-11-01

    Poor design of industrial trolleys lead to more compressive stress on the low back of industrial workers. The research work reported in this paper recommends a handle height of an industrial trolley for use by the local population, which reduces the compressive stress on the low back. Experiments were conducted in a laboratory on five subjects of varying stature 165, 173, 174, 175 and 182 cm, with five different handle heights 90, 95, 100, 105 and 110 cm. A four wheeled trolley has been used to conduct the experiments. Caster wheels diameters of 100, 125 and 150 mm made of polyurethane were used. It is found that a handle height of 110 cm allows the users to exert minimum force during the initial pushing. A biomechanical model was employed to calculate the compressive force experienced by L5/S1 disc and it is found that the compressive load will be the least when the handle height is 110 cm. Optimization of handle height using Genetic Algorithm approach, Heart rate analysis and EMG analysis confirm that a handle height of 110 cm and a wheel diameter of 150 mm will reduce the discomfort of industry workers pushing trolleys.

  8. Medical and nonmedical factors influencing utilization of delayed pushing in the second stage.

    PubMed

    Frey, Heather A; Tuuli, Methodius G; Cortez, Sarah; Odibo, Anthony O; Roehl, Kimberly A; Shanks, Anthony L; Macones, George A; Cahill, Alison G

    2013-08-01

    To evaluate factors impacting selection to delayed pushing in the second stage of labor. This case-control study was a secondary analysis of a large retrospective cohort study. Cases included women who delayed pushing for 60 minutes or more in the second stage of labor. Controls began pushing prior to 60 minutes from the time of diagnosis of complete dilation. Demographic, labor, and nonmedical factors were compared among cases and controls. Logistic regression modeling was used to identify factors independently associated with delayed pushing. We identified 471 women who delayed pushing and 4819 controls. Nulliparity, maternal body mass index > 25, high fetal station at complete dilation, regional anesthesia use, and start of second stage during staffing shift change were independent factors associated with increased use of delayed pushing. On the other hand, black race and second-stage management during night shift were associated with lower odds of employing delayed pushing. Delayed pushing was more commonly employed in nulliparous women, but 38.9% of multiparous women also delayed pushing. We identified multiple factors associated with use of delayed pushing. This study helps to define current patterns of second-stage labor management. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. Effect of light-curing units on push-out fiber post bond strength in root canal dentin

    NASA Astrophysics Data System (ADS)

    Calixto, L. R.; Bandéca, M. C.; Silva, F. B.; Rastelli, A. N. S.; Porto-Neto, S. T.; Andrade, M. F.

    2009-08-01

    The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples ( n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

  10. Push-pull partitioning tracer tests using radon-222 to quantify non-aqueous phase liquid contamination.

    PubMed

    Davis, B M; Istok, J D; Semprini, L

    2002-09-01

    Naturally occurring radon in groundwater can be used as an in situ partitioning tracer for locating and quantifying non-aqueous phase liquid (NAPL) contamination in the subsurface. When combined with the single-well, push-pull test, this methodology has the potential to provide a low-cost alternative to inter-well partitioning tracer tests. During a push-pull test, a known volume of test solution (radon-free water containing a conservative tracer) is first injected ("pushed") into a well; flow is then reversed and the test solution/groundwater mixture is extracted ("pulled") from the same well. In the presence of NAPL radon transport is retarded relative to the conservative tracer. Assuming linear equilibrium partitioning, retardation factors for radon can be used to estimate NAPL saturations. The utility of this methodology was evaluated in laboratory and field settings. Laboratory push-pull tests were conducted in both non-contaminated and trichloroethene NAPL (TCE)-contaminated sediment. The methodology was then applied in wells located in non-contaminated and light non-aqueous phase liquid (LNAPL)-contaminated portions of an aquifer at a former petroleum refinery. The method of temporal moments and an approximate analytical solution to the governing transport equations were used to interpret breakthrough curves and estimate radon retardation factors; estimated retardation factors were then used to calculate TCE saturations. Numerical simulations were used to further investigate the behavior of the breakthrough curves. The laboratory and field push-pull tests demonstrated that radon retardation does occur in the presence of TCE and LNAPL and that radon retardation can be used to calculate TCE saturations. Laboratory injection-phase test results in TCE-contaminated sediment yielded radon retardation factors ranging from 1.1 to 1.5, resulting in calculated TCE saturations ranging from 0.2 to 0.9%. Laboratory extraction-phase test results in the same sediment

  11. Biomechanical Analysis of Suspension Training Push-Up.

    PubMed

    Giancotti, Giuseppe F; Fusco, Andrea; Varalda, Carlo; Capranica, Laura; Cortis, Cristina

    2018-03-01

    Giancotti, GF, Fusco, A, Varalda, C, Capranica, L, and Cortis, C. Biomechanical analysis of suspension training push-up. J Strength Cond Res 32(3): 602-609, 2018-The aims of this study were to evaluate the load distribution between upper and lower extremities during suspension training (ST) push-up at different lengths of ST device and to predict useful equations to estimate the training load. After giving informed consent for participation, 25 subjects (17 men and 8 women; age = 28.1 ± 5.2 years; body mass = 69.4 ± 14.3 kg; height = 171.6 ± 11.3 cm; body mass index (BMI) = 23.4 ± 3.3 kg·m) were involved in the study. Each subject performed 14 static push-ups at 7 different lengths of ST device in 2 different elbow positions. The load distribution between upper and lower extremities was evaluated through a load cell and a force platform, respectively. To evaluate body inclination, all tests were recorded and analyzed through motion analysis software. To estimate the training load, a multilevel model regression (p ≤ 0.05) was used. Results showed that when the length of the ST device increased, the body inclination decreased, whereas the ground reaction force decreased and the load on the ST device increased. Moreover, when subjects moved from extended to flexed elbow, the ground reaction force decreased and the load on the ST device increased. In the created regression model (intraclass correlation coefficient = 0.24), the reaction force was the dependent variable, whereas the length of the ST device, BMI, and elbow position were the independent variables. The main findings were that the load distribution between upper and lower extremities changes both when modifying the body inclination and the length of the straps. The use of predicted equations could help practitioners to personalize the workouts according to different specific aims by modifying the length of the ST device to guarantee load progression.

  12. Alternative Fuels

    EPA Pesticide Factsheets

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  13. Adult Literacy in Africa: The Push and Pull Factors

    NASA Astrophysics Data System (ADS)

    Omolewa, Michael

    2008-11-01

    This paper examines the question of why Africa has made such slow progress towards the goal of eradicating illiteracy, and why it remains an exceptionally disadvantaged region in this respect. The article surveys the history of the development of literacy in Africa from colonial times to the present day, focusing on the role of adult education in pursuing the goal of universal literacy. The author seeks to identify both the "push" factors (those favouring the pursuit of this goal) and the "pull" factors (the obstacles and hindrances), examining these factors at the local, national and international levels. The author concludes that, while the literacy challenge in Africa remains a formidable one, there are examples of successful initiatives that give hope for the future.

  14. Sleeve Push Technique: A Novel Method of Space Gaining.

    PubMed

    Verma, Sanjeev; Bhupali, Nameksh Raj; Gupta, Deepak Kumar; Singh, Sombir; Singh, Satinder Pal

    2018-01-01

    Space gaining is frequently required in orthodontics. Multiple loops were initially used for space gaining and alignment. The most common used mechanics for space gaining is the use of nickel-titanium open coil springs. The disadvantage of nickel-titanium coil spring is that they cannot be used until the arches are well aligned to receive the stiffer stainless steel wires. Therefore, a new method of gaining space during initial alignment and leveling has been developed and named as sleeve push technique (SPT). The nickel-titanium wires, i.e. 0.012 inches and 0.014 inches along with archwire sleeve (protective tubing) can be used in a modified way to gain space along with alignment. This method helps in gaining space right from day 1 of treatment. The archwire sleeve and nickel-titanium wire in this new SPT act as a mutually synergistic combination and provide the orthodontist with a completely new technique for space opening.

  15. Particle Engulfment and Pushing by Solidifying Interfaces LMS Mission Results

    NASA Technical Reports Server (NTRS)

    Juretzko, Frank R.; Catalina, Adrian V.; Stefanescu, Doru M.; Dhindaw, Brij K.; Sen, Subhayu; Curreri, Peter A.; Mullins, Jennifer

    1998-01-01

    Results of the directional solidification experiments on Particle Engulfment and Pushing by Solidifying Interfaces (PEP) conducted on the space shuttle Columbia are reported. The experiment was manifested as part of The Life and Microgravity Science Mission. Two pure aluminum (99.999%) 9 mm cylindrical rods, loaded with about 2 vol.% 500 microns diameter zirconia particles were melted and directionally solidified in the microgravity (micro-g) environment of the shuttle. The particles were non-reactive with the matrices within the temperature range of interest. The experiments were conducted such as to insure a planar solid/liquid interface during solidification. Two different cartridge - crucible - sample designs were used: a spring-piston and expansion void. Both resulted in sound samples. Samples were evaluated post-flight for soundness by X-ray computer tomography (XCT).

  16. Probe tip heating assembly

    SciTech Connect

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably receivedmore » and clamped within the socket.« less

  17. Probe tip heating assembly

    DOEpatents

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  18. Forwardly-placed firearm fire control assembly

    DOEpatents

    Frickey, Steven J.

    2001-12-22

    A firearm fire control assembly for disposition in a forwardly placed support-hand operative relationship within a firearm having a combination of a firing pin and a firearm hammer adapted to engage and fire a cartridge, a sear assembly to alternately engage and disengage the combination of the firearm hammer and firing pin, and a trigger assembly including a movable trigger mechanism that is operable to engage the sear assembly to cause the firearm hammer firing pin combination to fire the firearm, a fire control assembly including a fire control depression member and a fire control rod operably connected to the depression member, and being positioned in a forward disposition disposed within a forestock of the firearm, and the depression member adapted to be operably engaged and depressed by the user's conventional forwardly placed support hand to maneuver the fire control rod to provide firing control of the firing of the firearm.

  19. A fully integrated W-band push-push CMOS VCO with low phase noise and wide tuning range.

    PubMed

    Wang, To-Po

    2011-07-01

    A circuit topology suitable for a low-phase-noise wide-tuning-range push-push voltage-controlled oscillator (VCO) is proposed in this paper. By applying varactors connected between drain and source terminations of the cross-coupled pair, the tuning range is effectively increased and the phase noise is improved. Moreover, a small capacitor is inserted between the VCO core and testing buffer to reduce loading effects on the VCO core. Furthermore, the enhanced second-harmonic output signal is extracted at middle of the varactors, leading to the elimination of RF choke at VCO's second-harmonic output port and a reduced chip size. Based on the proposed architecture, this VCO fabricated in 0.18-μm CMOS exhibits a measured 6.35% tuning range. Operating at a supply voltage of 1.2 V, the VCO core consumes 7.5-mW dc power, and the measured phase noise is -75 dBc/Hz and -91.5 dBc/Hz at 100-kHz and 1-MHz offsets from the 77.8-GHz carrier, respectively. Compared with previously published silicon-based VCOs over 70 GHz, this work can simultaneously achieve low phase noise, wide tuning range, and low dc power consumption, leading to a superior figure of merit (FOM), and better figure of merit considering the tuning range (FOM(T)). In addition, this fully integrated VCO also demonstrates the highest operation frequency among previously published 0.18-μm CMOS VCOs.

  20. Global Models of Ridge-Push Force, Geoid, and Lithospheric Strength of Oceanic plates

    NASA Astrophysics Data System (ADS)

    Mahatsente, Rezene

    2017-12-01

    An understanding of the transmission of ridge-push related stresses in the interior of oceanic plates is important because ridge-push force is one of the principal forces driving plate motion. Here, I assess the transmission of ridge-push related stresses in oceanic plates by comparing the magnitude of the ridge-push force to the integrated strength of oceanic plates. The strength is determined based on plate cooling and rheological models. The strength analysis includes low-temperature plasticity (LTP) in the upper mantle and assumes a range of possible tectonic conditions and rheology in the plates. The ridge-push force has been derived from the thermal state of oceanic lithosphere, seafloor depth and crustal age data. The results of modeling show that the transmission of ridge-push related stresses in oceanic plates mainly depends on rheology and predominant tectonic conditions. If a lithosphere has dry rheology, the estimated strength is higher than the ridge-push force at all ages for compressional tectonics and at old ages (>75 Ma) for extension. Therefore, under such conditions, oceanic plates may not respond to ridge-push force by intraplate deformation. Instead, the plates may transmit the ridge-push related stress in their interior. For a wet rheology, however, the strength of young lithosphere (<75 Ma) is much less than the ridge-push force for both compressional and extensional tectonics. In this case, the ridge-push related stress may dissipate in the interior of oceanic plates and diffuses by intraplate deformation. The state of stress within a plate depends on the balance of far-field and intraplate forces.

  1. Spaces of Difference: The Contradictions of Alternative Educational Programs

    ERIC Educational Resources Information Center

    Vadeboncoeur, Jennifer A.

    2009-01-01

    Drawing upon the concept of "thirdspace" (Soja 1996), this article extends sociocultural theorizations of space in relation to alternative educational programs: programs designed to re-engage youth who have been pushed out of mainstream schools. Snapshots of educational programs, provided by ethnographic research gathered in the United…

  2. Structural assembly in space

    NASA Technical Reports Server (NTRS)

    Stokes, J. W.; Pruett, E. C.

    1980-01-01

    A cost algorithm for predicting assembly costs for large space structures is given. Assembly scenarios are summarized which describe the erection, deployment, and fabrication tasks for five large space structures. The major activities that impact total costs for structure assembly from launch through deployment and assembly to scientific instrument installation and checkout are described. Individual cost elements such as assembly fixtures, handrails, or remote minipulators are also presented.

  3. Inlet nozzle assembly

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Knight, R.C.; Precechtel, D.R.; Smith, B.G.

    1985-09-09

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  4. Tilt assembly for tracking solar collector assembly

    DOEpatents

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  5. Electroreductive Coupling Layer-by-Layer Assembly.

    PubMed

    Kang, Shusen; Wang, Lei; Zhang, Jian; Du, Jia; Li, Mao; Chen, Qidai

    2017-09-20

    Rapid and covalent layer-by-layer (LbL) assembly is of significance for practical applications because of superior chemical and mechanical stability. The electrochemical LbL assembly via an accelerating trigger can be automated and programmable in response to electrical signals to in situ fabricate covalently layered thin films with chemical and mechanical stability. In this paper, electroreductive coupling layer-by-layer assembly is introduced as both covalent and rapid methodology for preparing layered thin films. This assembly is triggered by C-C coupling of peripheral alkynyls, which have own absorption below 300 nm and can transform to optical and electrical inert double/single or triple/single alternative bonding formations significantly without optical or electric alternations of desirable photoelectric building blocks, superior to other linkers among covalent LbL assemblies. Not limited to fabrication of optical thin films, this assembly is readily available for oxygen sensitive substrates or materials and also a powerful addition to electrooxidative coupling LbL assembly for developing the economically dynamoelectric LbL machines without moving or changing experimental gears.

  6. Oviposition Preferences of Pickleworm (Lepidoptera: Crambidae) in Relation to a Potential Push-Pull Cropping Management Approach.

    PubMed

    Leiner, R C; Spafford, H

    2016-04-25

    Pickleworm, Diaphania nitidalis Cramer (Lepidoptera: Crambidae), is a major pest of cucurbits. The current management approach for this pest is weekly insecticide applications. A push-pull cropping approach may be an alternative management practice and could reduce reliance on pesticides. One potential push-pull scenario is the use of squash (Cucurbita pepo L.) as a trap crop and watermelon (Citrullus lanatus [Thunb.] Matsum. & Nakai) as a deterrent intercrop to manage pickleworm on cantaloupe (Cucumis melo L.). This study investigated if the underlying mechanism required for the success of this management approach (a female oviposition preference or nonpreference among squash, cantaloupe, and watermelon) is present. A series of oviposition preference experiments was conducted to see how individual females responded when presented with different host plants for oviposition. Under laboratory conditions, when females had the choice of a leaf from squash, cantaloupe, and watermelon, they laid a higher proportion of their eggs on the cantaloupe leaf. However, under greenhouse conditions, when females were presented with whole plants of the three different species, they laid a higher percent of their eggs on the squash plant. Females laid a similar number of eggs on watermelon as compared with cantaloupe under greenhouse conditions, and appeared to not be averse to laying their eggs on watermelon. However, when presented with a noncucurbit, such as bean, females laid a low number of total eggs. Overall, it appears that squash may be more preferred as an oviposition substrate than cantaloupe or watermelon and may be a useful trap crop or pull. Further study to determine a suitable deterrent intercrop or push and evaluation of the proposed system under field conditions are needed. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Educational Exclusion: Drop Out, Push Out, and School-to-Prison Pipeline among LGBTQ Youth

    ERIC Educational Resources Information Center

    Gay, Lesbian and Straight Education Network (GLSEN), 2016

    2016-01-01

    "Educational Exclusion: Drop Out, Push Out, and the School-to-Prison Pipeline among LGBTQ Youth" provides an in-depth look at the conditions that effectively push LGBTQ youth out of school and potentially into the criminal justice system. The report provides specific, real world guidance to address the hostile school climates and…

  8. On Reducing Delay in Mesh-Based P2P Streaming: A Mesh-Push Approach

    NASA Astrophysics Data System (ADS)

    Liu, Zheng; Xue, Kaiping; Hong, Peilin

    The peer-assisted streaming paradigm has been widely employed to distribute live video data on the internet recently. In general, the mesh-based pull approach is more robust and efficient than the tree-based push approach. However, pull protocol brings about longer streaming delay, which is caused by the handshaking process of advertising buffer map message, sending request message and scheduling of the data block. In this paper, we propose a new approach, mesh-push, to address this issue. Different from the traditional pull approach, mesh-push implements block scheduling algorithm at sender side, where the block transmission is initiated by the sender rather than by the receiver. We first formulate the optimal upload bandwidth utilization problem, then present the mesh-push approach, in which a token protocol is designed to avoid block redundancy; a min-cost flow model is employed to derive the optimal scheduling for the push peer; and a push peer selection algorithm is introduced to reduce control overhead. Finally, we evaluate mesh-push through simulation, the results of which show mesh-push outperforms the pull scheduling in streaming delay, and achieves comparable delivery ratio at the same time.

  9. DELINEATION OF SUBSURFACE HYDROCARBON CONTAMINANT DISTRIBUTION USING A DIRECT PUSH RESISTIVITY METHOD

    EPA Science Inventory

    A direct push resistivity method was evaluated as a complementary screening tool to provide rapid in-situ contaminant detection to aid in better defining locations for drilling, sampling, and monitoring well installation at hazardous waste sites. Nine continuous direct push resi...

  10. Spontaneous pushing to prevent postpartum urinary incontinence: a randomized, controlled trial.

    PubMed

    Low, Lisa Kane; Miller, Janis M; Guo, Ying; Ashton-Miller, James A; DeLancey, John O L; Sampselle, Carolyn M

    2013-03-01

    The risk for urinary incontinence can be 2.6-fold greater in women after pregnancy and childbirth compared with their never-pregnant counterparts, with the incidence increasing with parity. We tested the hypothesis that the incidence of de novo postpartum urinary incontinence in primiparous women is reduced with the use of spontaneous pushing alone or in combination with perineal massage compared with women who experienced traditional directed pushing for second-stage management. This was a prospective clinical trial enrolling and randomizing 249 women into a four-group design: (1) routine care with coached or directed pushing, (2) spontaneous self-directed pushing, (3) prenatal perineal massage initiated in the third trimester, and (4) the combination of spontaneous pushing plus perineal massage. Self-report of incontinence was assessed using analysis of variance (ANOVA) and covariance (ANCOVA) models in 145 remaining women at 12 months postpartum using the Leakage Index, which is sensitive to minor leakage. No statistical difference in the incidence of de novo postpartum incontinence was found based on method of pushing (spontaneous/directed) (P value = 0.57) or in combination with prenatal perineal massage (P value = 0.57). Fidelity to pushing treatment of type was assessed and between-groups crossover detected. Spontaneous pushing did not reduce the incidence of postpartum incontinence experienced by women 1 year after their first birth due to high cross-over between randomization groups.

  11. Enhanced Basicity of Push-Pull Nitrogen Bases in the Gas Phase.

    PubMed

    Raczyńska, Ewa D; Gal, Jean-François; Maria, Pierre-Charles

    2016-11-23

    Nitrogen bases containing one or more pushing amino-group(s) directly linked to a pulling cyano, imino, or phosphoimino group, as well as those in which the pushing and pulling moieties are separated by a conjugated spacer (C═X) n , where X is CH or N, display an exceptionally strong basicity. The n-π conjugation between the pushing and pulling groups in such systems lowers the basicity of the pushing amino-group(s) and increases the basicity of the pulling cyano, imino, or phosphoimino group. In the gas phase, most of the so-called push-pull nitrogen bases exhibit a very high basicity. This paper presents an analysis of the exceptional gas-phase basicity, mostly in terms of experimental data, in relation with structure and conjugation of various subfamilies of push-pull nitrogen bases: nitriles, azoles, azines, amidines, guanidines, vinamidines, biguanides, and phosphazenes. The strong basicity of biomolecules containing a push-pull nitrogen substructure, such as bioamines, amino acids, and peptides containing push-pull side chains, nucleobases, and their nucleosides and nucleotides, is also analyzed. Progress and perspectives of experimental determinations of GBs and PAs of highly basic compounds, termed as "superbases", are presented and benchmarked on the basis of theoretical calculations on existing or hypothetical molecules.

  12. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Radio communication used in shoving, backing or pushing movements. 220.49 Section 220.49 Transportation Other Regulations Relating to Transportation... Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or pushing...

  13. [Towards a better understanding and quantitative assessment of pushing, a postural behaviour caused by some strokes].

    PubMed

    Pérennou, D

    2005-05-01

    Postural control aims to build up and align the body orientation (posture) and stabilize body segments. The existence of two separate mechanisms, one for the control of body orientation with respect to gravity and one for its stabilisation, is an emerging concept that allows a better understanding of postural disorders, including pushing, after stroke. Objectives. - Literature review concerning pushing, one of the most puzzling postural behaviours after stroke. Critical review of papers indexed in Medline and book chapters dealing with pushing. There is no agreement about the definition of pushing: some authors consider that pushers push himself toward the paretic side using the healthy arm or leg; others consider that pushers lean (list) toward the side opposite the lesion and resist any attempt to become more upright. Surprisingly, the push itself has never been measured. Some ordinal scales have been recently proposed, but their psychometric properties have not been analysed. These methodological insufficiencies explain in part the disagreements about frequency (from 5% to 50% of patients with stroke) and cause(s) of pushing. Pushing may be the most dramatic clinical manifestations of an extreme bias in the construction of the biological vertical. We argue for a better assessment of vertical perception/representation after stroke involving the three modalities of the biological (subjective) vertical: the visual vertical, the haptic or tactile vertical, and especially the postural vertical.

  14. Pushing the threshold: how NMDAR antagonists induce homeostasis through protein synthesis to remedy depression

    PubMed Central

    Raab-Graham, Kimberly F.; Workman, Emily R.; Namjoshi, Sanjeev; Niere, Farr

    2016-01-01

    Healthy neurons have an optimal operating range, coded globally by the frequency of action potentials or locally by calcium. The maintenance of this range is governed by homeostatic plasticity. Here, we discuss how new approaches to treat depression alter synaptic activity. These approaches induce the neuron to recruit homeostatic mechanisms to relieve depression. Homeostasis generally implies that the direction of activity necessary to restore the neuron’s critical operating range is opposite in direction to its current activity pattern. Unconventional antidepressant therapies deep brain stimulation and NMDAR antagonists alter the neuron’s “depressed” state by pushing the neuron’s current activity in the same direction but to the extreme edge. These therapies rally the intrinsic drive of neurons in the opposite direction, thereby allowing the cell to return to baseline activity, form new synapses, and restore proper communication. In this review, we discuss seminal studies on protein synthesis dependent homeostatic plasticity and their contribution to our understanding of molecular mechanisms underlying the effectiveness of NMDAR antagonists as rapid antidepressants. Rapid antidepressant efficacy is likely to require a cascade of mRNA translational regulation. Emerging evidence suggests that changes in synaptic strength or intrinsic excitability converge on the same protein synthesis pathways, relieving depressive symptoms. Thus, we address the question: Are there multiple homeostatic mechanisms that induce the neuron and neuronal circuits to self-correct to regulate mood in vivo? Targeting alternative ways to induce homeostatic protein synthesis may provide, faster, safer, and longer lasting antidepressants. PMID:27125595

  15. Push or Pull: Changes in the Relative Risk and Growth of Entrepreneurship Among Older Households.

    PubMed

    Weller, Christian E; Wenger, Jeffrey B; Lichtenstein, Benyamin; Arcand, Carolyn

    2018-03-19

    Amid insufficient retirement savings and the growing need to work longer, it is important to understand why self-employment, especially entrepreneurship, has grown among older households. Older households may have been pushed into entrepreneurship by the growing risks of wage-and-salary employment as wages and jobs have become less stable. Alternatively, older households may have been pulled into entrepreneurship as the associated risks have declined, for instance, due to greater opportunities to diversify income away from risky business income. We examine the economic causes of the rise in entrepreneurship among older households. We use summary statistics and multinomial logit regressions to analyze the link between economic pressures in wage-and-salary employment, financial strength of entrepreneurship, and the presence and change of entrepreneurship among older households-aged 50 years or older. We use household data from the Federal Reserve's Survey of Consumer Finances from 1989 to 2013. We find little support for the claim that increased economic pressures are correlated with rising entrepreneurship. Instead, our results suggest that the growth of older entrepreneurship is coincident with increasing access to dividend and interest income. We also find some evidence that access to Social Security and other annuity benefits increases the likelihood of self-employment. Implications: Entrepreneurship among older households increasingly correlates with income diversification. Policymakers interested in encouraging more entrepreneurship among older households could consider increased access to income diversification through social insurance.

  16. Development of Augmentative and Alternative Communication Assessment Tools for Patients with ALS.

    PubMed

    Yonezaki, Jiro; Ikeda, Maki; Tsubaki, Takuya; Sato, Katsuya; Ito, Sin-Ichi; Sueda, Osamu; Fujisawa, Shoichiro

    2015-01-01

    ALS patients usually use augmentative and alternative communication tools to communicate with other people, but the assessment tools, including the selection of an input switch, are very difficult to operate. In this study, we developed a novel device to measure the physical ability of patients to operate the input switch with a push lever. The study focused on the amount of pushing and the power required to operate the input switch, and the effectiveness was verified.

  17. Muscular contribution to low-back loading and stiffness during standard and suspended push-ups.

    PubMed

    Beach, Tyson A C; Howarth, Samuel J; Callaghan, Jack P

    2008-06-01

    Push-up exercises are normally performed to challenge muscles that span upper extremity joints. However, it is also recognized that push-ups provide an effective abdominal muscle challenge, especially when the hands are in contact with a labile support surface. The purpose of this study was to compare trunk muscle activation levels and resultant intervertebral joint (IVJ) loading when standard and suspended push-ups were performed, and to quantify and compare the contribution of trunk muscles to IVJ rotational stiffness in both exercises. Eleven recreationally trained male volunteers performed sets of standard and suspended push-ups. Upper body kinematic, kinetic, and EMG data were collected and input into a 3D biomechanical model of the lumbar torso to quantify lumbar IVJ loading and the contributions of trunk muscles to IVJ rotational stiffness. When performing suspended push-ups, muscles of the abdominal wall and the latissimus dorsi were activated to levels that were significantly greater than those elicited when performing standard push-ups (p<.05). As a direct result of these increased activation levels, model-predicted muscle forces increased and consequently led to significantly greater mean (p=.0008) and peak (p=.0012) lumbar IVJ compressive forces when performing suspended push-ups. Also directly resulting from the increased activation levels of the abdominal muscles and the latissimus dorsi during suspended push-ups was increased muscular contribution to lumbar IVJ rotational stiffness (p<.05). In comparison to the standard version of the exercise, suspended push-ups appear to provide a superior abdominal muscle challenge. However, for individuals unable to tolerate high lumbar IVJ compressive loads, potential benefits gained by incorporating suspended push-ups into their resistance training regimen may be outweighed by the risk of overloading low-back tissues.

  18. Firearm trigger assembly

    DOEpatents

    Crandall, David L.; Watson, Richard W.

    2010-02-16

    A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly is not in the locked position.

  19. Autonomous electrochromic assembly

    DOEpatents

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacity state. The electrochromic assembly may be used in combination with a window.

  20. Firearm trigger assembly

    SciTech Connect

    Crandall, David L.; Watson, Richard W.

    2010-02-16

    A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly ismore » not in the locked position.« less

  1. Pushing the limits of nanolithography outside the box

    NASA Astrophysics Data System (ADS)

    Ocola, Leonidas

    The Center for Nanoscale Materials (CNM) at Argonne National Laboratory was constructed in 2006, and opened its doors to serve the user community in 2007 with the objective to provide research opportunities in Nanoscience for the scientific community worldwide. Currently, the CNM hosts over 400 user proposals a year. There are six research groups at the CNM that do work in nanophotonics, electronic and magnetic materials and devices, nanobio interfaces, nanofabrication and devices, x-ray nanoscale microscopy and theory and modeling. At the CNM Nanofabrication and Devices Group we have been able to push the limits of electron beam lithography to make plasmonic nanostructures obtain sharp corners with less than 6 nm radius of curvature and expand the use of ion beams to 3D large area nanofabrication in microfluidics by novel design methodologies, among other accomplishments. None of these accomplishments are possible without detailed understanding of the physics and chemistry mechanisms involved during fabrication. During my talk I will discuss a few clear cases where lithography and fabrication are used in ways not commonly found in current nanofabrication facilities and what make our facility unique. This work was supported by the Department of Energy under Contract No. DE-AC02-06CH11357. Use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  2. Pushing Particles with Waves: Current Drive and α-Channeling

    DOE PAGES

    FISCH, Nathaniel J.

    2016-01-01

    It can be advantageous to push particles with waves in tokamaks or other magnetic confinement devices, relying on wave-particle resonances to accomplish specific goals. Waves that damp on electrons or ions in toroidal fusion devises can drive currents if the waves are launched with toroidal asymmetry. Theses currents are important for tokamaks, since they operate in the absence of an electric field with curl, enabling steady state operation. The lower hybrid wave and the electron cyclotron wave have been demonstrated to drive significant currents. Non-inductive current also stabilizes deleterious tearing modes. Waves can also be used to broker the energymore » transfer between energetic alpha particles and the background plasma. Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled instead into useful energy, that heats fuel ions or drives current. Furthermore, an important question is the extent to which these effects can be accomplished together.« less

  3. Computer modeling of particle pushing and clustering during matrix crystallization

    SciTech Connect

    Shelton, R.K.; Dunand, D.C.

    1996-11-01

    Two-dimensional cellular automation computer simulations were carried out to model the geometric interaction between mobile, equiaxed particles and growing matrix grains, thus simulating crystallization (respectively, recrystallization, phase transformation or solidification) of a matrix material containing a mobile second phase (e.g., solid particles, liquid droplets or gas bubbles). The model allows the study of particle pushing by growing grains, which leads to particle accumulation and clustering at grain boundaries and triple points, and concomitant particle depletion within grains. Parameters explored are particle area fraction, particle settling speed, particle cluster mobility and grain nucleation rate under continuous nucleation conditions. These parameters aremore » found to strongly affect the particle spatial distribution and clustering during and after crystallization. Conversely, the particles have no measurable effect on the grain shape or size. Finally, site-saturated nucleation at the boundaries of the simulation field is investigated, simulating e.g., solidification from crucible walls or recrystallization from sample edges. Pronounced clustering of particles takes place at grain boundaries and is further accentuated by particle settling.« less

  4. Pull or Push? Octopuses Solve a Puzzle Problem

    PubMed Central

    Richter, Jonas N.; Hochner, Binyamin; Kuba, Michael J.

    2016-01-01

    Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone. PMID:27003439

  5. Security-Enhanced Push Button Configuration for Home Smart Control.

    PubMed

    Han, Junghee; Park, Taejoon

    2017-06-08

    With the emergence of smart and converged home services, the need for the secure and easy interplay of various devices has been increased. Push Button Configuration (PBC) is one of the technologies proposed for easy set-up of a secure session between IT and consumer devices. Although the Wi-Fi Direct specification explicitly states that all devices must support the PBC method, its applicability is very limited. This is because the security vulnerability of PBC can be maliciously exploited so that attackers can make illegitimate sessions with consumer devices. To address this problem, this paper proposes a novel Security-enhanced PBC (SePBC) scheme with which we can uncover suspicious or malicious devices. The proposed mechanism has several unique features. First, we develop a secure handshake distance measurement protocol by preventing an adversary sitting outside the region from maliciously manipulating its distance to be fake. Second, it is compatible with the original Wi-Fi PBC without introducing a brand-new methodology. Finally, SePBC uses lightweight operations without CPU-intensive cryptography computation and employs inexpensive H/W. Moreover, it needs to incur little overhead when there is no attack. This paper also designs and implements the proposed SePBC in the real world. Our experimental results and analysis show that the proposed SePBC scheme effectively defeats attacks on PBC while minimizing the modification of the original PBC equipment.

  6. Simple push coating of polymer thin-film transistors

    PubMed Central

    Ikawa, Mitsuhiro; Yamada, Toshikazu; Matsui, Hiroyuki; Minemawari, Hiromi; Tsutsumi, Jun'ya; Horii, Yoshinori; Chikamatsu, Masayuki; Azumi, Reiko; Kumai, Reiji; Hasegawa, Tatsuo

    2012-01-01

    Solution processibility is a unique advantage of organic semiconductors, permitting the low-cost production of flexible electronics under ambient conditions. However, the solution affinity to substrate surfaces remains a serious dilemma; liquid manipulation is more difficult on highly hydrophobic surfaces, but the use of such surfaces is indispensable for improving device characteristics. Here we demonstrate a simple technique, which we call ‘push coating’, to produce uniform large-area semiconducting polymer films over a hydrophobic surface with eliminating material loss. We utilize a poly(dimethylsiloxane)-based trilayer stamp whose conformal contact with the substrate enables capillarity-induced wetting of the surface. Films are formed through solvent sorption and retention in the stamp, allowing the stamp to be peeled perfectly from the film. The planar film formation on hydrophobic surfaces also enables subsequent fine film patterning. The technique improves the crystallinity and field-effect mobility of stamped semiconductor films, constituting a major step towards flexible electronics production. PMID:23132026

  7. On push-forward representations in the standard gyrokinetic model

    SciTech Connect

    Miyato, N., E-mail: miyato.naoaki@jaea.go.jp; Yagi, M.; Scott, B. D.

    2015-01-15

    Two representations of fluid moments in terms of a gyro-center distribution function and gyro-center coordinates, which are called push-forward representations, are compared in the standard electrostatic gyrokinetic model. In the representation conventionally used to derive the gyrokinetic Poisson equation, the pull-back transformation of the gyro-center distribution function contains effects of the gyro-center transformation and therefore electrostatic potential fluctuations, which is described by the Poisson brackets between the distribution function and scalar functions generating the gyro-center transformation. Usually, only the lowest order solution of the generating function at first order is considered to explicitly derive the gyrokinetic Poisson equation. This ismore » true in explicitly deriving representations of scalar fluid moments with polarization terms. One also recovers the particle diamagnetic flux at this order because it is associated with the guiding-center transformation. However, higher-order solutions are needed to derive finite Larmor radius terms of particle flux including the polarization drift flux from the conventional representation. On the other hand, the lowest order solution is sufficient for the other representation, in which the gyro-center transformation part is combined with the guiding-center one and the pull-back transformation of the distribution function does not appear.« less

  8. Tunable Push-Pull Interactions in 5-Nitrosopyrimidines.

    PubMed

    Procházková, Eliška; Čechová, Lucie; Tarábek, Ján; Janeba, Zlatko; Dračínský, Martin

    2016-05-06

    The effect of push-pull interactions in a series of variously substituted 5-nitrosopyrimidines on the strength of intramolecular hydrogen bonds, the height of rotational barriers around formally single bonds, UV-vis spectra and electrochemical behavior is explored. Intramolecular charge transfer (ICT) leads to a shift of electron density from electron-donating substituents, which is readily observable by NMR spectroscopy. The 5-nitroso group is able to form strong intramolecular hydrogen bonds with neighboring amino substituents. As a result, two rotamers with reversed orientation of the 5-nitroso group are observed for compounds with two different hydrogen-bond donors in neighboring positions. The barriers of interconversion between the two rotamers are strongly influenced by ICT, whereas the ratio of such rotamers depends primarily on the character of the hydrogen-bond donors. The ICT also significantly affects the position of UV-vis absorption maxima, which can be tuned in a broad range of 100 nm by the selection of appropriate substituents. Finally, ICT influences oxidation potential of the 5-nitrosopyrimidines and the stability of the resulting nitroso radical cations, the structures of which are determined by EPR spectroscopy.

  9. Self Assembled Particles

    NASA Technical Reports Server (NTRS)

    Palacci, Jeremie (Inventor); Sacanna, Stefano (Inventor); Pine, David J. (Inventor); Chaikin, Paul Michael (Inventor)

    2017-01-01

    A self-assembling structure using non-equilibrium driving forces leading to 'living crystals' and other maniputable particles with a complex dynamics. The dynamic self-assembly assembly results from a competition between self-propulsion of particles and an attractive interaction between the particles. As a result of non-equilibrium driving forces, the crystals form, grow, collide, anneal, repair themselves and spontaneously self-destruct, thereby enabling reconfiguration and assembly to achieve a desired property.

  10. Shoulder muscle activation during stable and suspended push-ups at different heights in healthy subjects.

    PubMed

    Borreani, Sebastien; Calatayud, Joaquin; Colado, Juan C; Tella, Victor; Moya-Nájera, Diego; Martin, Fernando; Rogers, Michael E

    2015-08-01

    To analyze shoulder muscle activation when performing push-ups under different stability conditions and heights. Comparative study by repeated measures. Valencia University laboratory. 29 healthy males participated. Subjects performed 3 push-ups each with their hands at 2 different heights (10 vs. 65 cm) under stable conditions and using a suspension device. Push-up speed was controlled and the testing order was randomized. The average amplitudes of the electromyographic root mean square of the long head of the triceps brachii (TRICEP), upper trapezius (TRAPS), anterior deltoid (DELT) and clavicular pectoralis (PEC) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Suspended push-ups at 10 cm resulted in greater activation in the TRICEP (17.14 ± 1.31 %MVIC vs. 37.03 ± 1.80 %MVIC) and TRAPS (5.83 ± 0.58 %MVIC vs. 14.69 ± 1.91 %MVIC) than those performed on the floor. For DELT and PEC similar or higher activation was found performing the push-ups on the floor, respectively. Height determines different muscle activation patterns. Stable push-ups elicit similar PEC and higher DELT muscle activation, being greater at 10 cm; whereas suspended push-ups elicit greater TRAPS and TRICEP muscle activation, being greater at 65 cm. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Dynamic push-pull characteristics at three hand-reach envelopes: applications for the workplace.

    PubMed

    Calé-Benzoor, Maya; Dickstein, Ruth; Arnon, Michal; Ayalon, Moshe

    2016-01-01

    Pushing and pulling are common tasks in the workplace. Overexertion injuries related to manual pushing and pulling are often observed, and therefore the understanding of work capacity is important for efficient and safe workstation design. The purpose of the present study was to describe workloads obtained during different reach envelopes during a seated push-pull task. Forty-five women performed an isokinetic push-pull sequence at two velocities. Strength, work and agonist/antagonist muscle ratio were calculated for the full range of motion (ROM). We then divided the ROM into three reach envelopes - neutral, medium, and maximum reach. The work capacity for each direction was determined and the reach envelope work data were compared. Push capability was best at medium reach envelope and pulling was best at maximum reach envelope. Push/pull strength ratio was approximately 1. A recommendation was made to avoid strenuous push-pull tasks at neutral reach envelopes. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  12. Alternative metrics

    NASA Astrophysics Data System (ADS)

    2012-11-01

    As the old 'publish or perish' adage is brought into question, additional research-impact indices, known as altmetrics, are offering new evaluation alternatives. But such metrics may need to adjust to the evolution of science publishing.

  13. Magnetic self-assembly of small parts

    NASA Astrophysics Data System (ADS)

    Shetye, Sheetal B.

    Modern society's propensity for miniaturized end-user products is compelling electronic manufacturers to assemble and package different micro-scale, multi-technology components in more efficient and cost-effective manners. As the size of the components gets smaller, issues such as part sticking and alignment precision create challenges that slow the throughput of conventional robotic pick-n-place systems. As an alternative, various self-assembly approaches have been proposed to manipulate micro to millimeter scale components in a parallel fashion without human or robotic intervention. In this dissertation, magnetic self-assembly (MSA) is demonstrated as a highly efficient, completely parallel process for assembly of millimeter scale components. MSA is achieved by integrating permanent micromagnets onto component bonding surfaces using wafer-level microfabrication processes. Embedded bonded powder methods are used for fabrication of the magnets. The magnets are then magnetized using pulse magnetization methods, and the wafers are then singulated to form individual components. When the components are randomly mixed together, self-assembly occurs when the intermagnetic forces overcome the mixing forces. Analytical and finite element methods (FEM) are used to study the force interactions between the micromagnets. The multifunctional aspects of MSA are presented through demonstration of part-to-part and part-to-substrate assembly of 1 mm x 1mm x 0.5 mm silicon components. Part-to-part assembly is demonstrated by batch assembly of free-floating parts in a liquid environment with the assembly yield of different magnetic patterns varying from 88% to 90% in 20 s. Part-to-substrate assembly is demonstrated by assembling an ordered array onto a fixed substrate in a dry environment with the assembly yield varying from 86% to 99%. In both cases, diverse magnetic shapes/patterns are used to control the alignment and angular orientation of the components. A mathematical model is

  14. Membrane module assembly

    DOEpatents

    Kaschemekat, J.

    1994-03-15

    A membrane module assembly is described which is adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation. 2 figures.

  15. Membrane module assembly

    DOEpatents

    Kaschemekat, Jurgen

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

  16. YSO inner disk chemistry - pushing the IRS limits

    NASA Astrophysics Data System (ADS)

    Lahuis, Fred; Blake, Geoffrey; Boogert, Adwin; Dullemond, Cornelis; Evans, Neal; Hogerheijde, Michiel; Pontoppidan, Klaus; van Dishoeck, Ewine

    2007-05-01

    The aim of this proposal is to observe molecular absorption bands at 13-15 micron of gaseous acetylene (C2H2), hydrogen cyanide (HCN), and carbon dioxide (CO2) in the planet-forming zones of a sample of nearly edge-on disk sources. These molecules are predicted to be among the most abundant organic molecules in hot gas and the precursors of much more complex, prebiotic species. In addition to being unique probes of inner disk chemistry, the molecular bands also provide a direct measure of the temperature and density of the warm gas in the planet-forming zones of disks. The presence of warm C2H2, HCN, and CO2 gas has already been reported in two proto-planetary disks. However, in existing IRS observations of other disks, the bands of these molecules are expected to lie just below the detection limit allowed by the achieved dynamic range. We have designed a new observing strategy designed to push the achievable dynamic range of the SH module by at least a factor of 3-5 to conduct the most sensitive search possible in sixteen disks. The targets have been selected on basis of deep absorption at 4.7 micron due to warm CO gas in the inner disk. The data will most certainly be the driving force for further development of optimal extraction algorithms (developed as part of the c2d legacy program) to obtain the highest S/N spectra of which the IRS is capable.

  17. Muscle Activation during Push-Ups with Different Suspension Training Systems

    PubMed Central

    Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C.; Martín, Fernando F; Rogers, Michael E.; Behm, David G.; Andersen, Lars L.

    2014-01-01

    The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29) performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p < 0.001). Individually, the suspended push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation. Key Points Compared with standard push-ups on the floor, suspended push-ups increase core muscle activation. A one-anchor system with a pulley is the best option to increase TRICEP, TRAPS, LUMB and FEM muscle activity. More stable conditions such as the standard push-up or a parallel band system provide greater increases in DELT and PEC muscle activation. A suspended push-up is an effective method to achieve high muscle activity levels in the ABS. PMID:25177174

  18. Muscle Activation during Push-Ups with Different Suspension Training Systems.

    PubMed

    Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C; Martín, Fernando F; Rogers, Michael E; Behm, David G; Andersen, Lars L

    2014-09-01

    The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29) performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p < 0.001). Individually, the suspended push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation. Key PointsCompared with standard push-ups on the floor, suspended push-ups increase core muscle activation.A one-anchor system with a pulley is the best option to increase TRICEP, TRAPS, LUMB and FEM muscle activity.More stable conditions such as the standard push-up or a parallel band system provide greater increases in DELT and PEC muscle activation.A suspended push-up is an effective method to achieve high muscle activity levels in the ABS.

  19. Sensor mount assemblies and sensor assemblies

    DOEpatents

    Miller, David H [Redondo Beach, CA

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  20. Automated Simultaneous Assembly for Multistage Testing

    ERIC Educational Resources Information Center

    Breithaupt, Krista; Ariel, Adelaide; Veldkamp, Bernard P.

    2005-01-01

    This article offers some solutions used in the assembly of the computerized Uniform Certified Public Accountancy (CPA) licensing examination as practical alternatives for operational programs producing large numbers of forms. The Uniform CPA examination was offered as an adaptive multistage test (MST) beginning in April of 2004. Examples of…

  1. Assembly-line Simulation Program

    NASA Technical Reports Server (NTRS)

    Chamberlain, Robert G.; Zendejas, Silvino; Malhotra, Shan

    1987-01-01

    Costs and profits estimated for models based on user inputs. Standard Assembly-line Manufacturing Industry Simulation (SAMIS) program generalized so useful for production-line manufacturing companies. Provides accurate and reliable means of comparing alternative manufacturing processes. Used to assess impact of changes in financial parameters as cost of resources and services, inflation rates, interest rates, tax policies, and required rate of return of equity. Most important capability is ability to estimate prices manufacturer would have to receive for its products to recover all of costs of production and make specified profit. Written in TURBO PASCAL.

  2. A Straightforward Random Walk Model for Fast Push-Pull Tracer Test Evaluation.

    PubMed

    Klotzsch, Stephan; Binder, Martin; Händel, Falk

    2017-01-01

    In this article, we present a straightforward random walk model for fast evaluation of push-pull tracer tests. By developing an adaptive algorithm, we overcome the problem of manually defining how many particles have to be used to simulate the transport problem. Beside this, we validate the random walk model by evaluating a push-pull tracer test with drift phase and confirm the results with MT3DMS. The random walk model took less than 1% of computational time of MT3DMS, thus allowing a remarkable faster evaluation of push-pull tracer tests. © 2016, National Ground Water Association.

  3. Clinical and hormonal aspects in breast cancer with special reference to malignant evolutive push.

    PubMed

    Kiricuta, I; Frenkel, Z; Munteanu, S

    1975-01-01

    It is tried to differentiate between various stages of malignant evolutive push and normal mammary tumors to establish an individual therapeutic procedure. Besides mammography and thermometry, investigations of urinary excretions of estrogenic and androgenic steriods are qualified for this purpose. Patients with malignant evolutive push showed an increased excretion of estrogens which reached its highest levels in patients suffering from inflammatory mammary carcinomas. The excretion of 17-ketosteroids shows a behaviour vice versa. Altogether mammary tumors with malignant evolutive push are characterized by a state of absolute and relative hyperestrogenity respectively. This phenomenon preferably depends on the clinical stage of the disease than on the age of the patients.

  4. Interconnect assembly for an electronic assembly and assembly method therefor

    DOEpatents

    Gerbsch, Erich William

    2003-06-10

    An interconnect assembly and method for a semiconductor device, in which the interconnect assembly can be used in lieu of wirebond connections to form an electronic assembly. The interconnect assembly includes first and second interconnect members. The first interconnect member has a first surface with a first contact and a second surface with a second contact electrically connected to the first contact, while the second interconnect member has a flexible finger contacting the second contact of the first interconnect member. The first interconnect member is adapted to be aligned and registered with a semiconductor device having a contact on a first surface thereof, so that the first contact of the first interconnect member electrically contacts the contact of the semiconductor device. Consequently, the assembly method does not require any wirebonds, but instead merely entails aligning and registering the first interconnect member with the semiconductor device so that the contacts of the first interconnect member and the semiconductor device make electrically contact, and then contacting the second contact of the first interconnect member with the flexible finger of the second interconnect member.

  5. Magnetically mediated vortexlike assembly of gold nanoshells.

    PubMed

    Sun, Jianfei; Dong, Jian; Sun, Dongke; Guo, Zhirui; Gu, Ning

    2012-04-24

    Gold nanoshells currently attract increasing research interests due to the important role in many subjects. For practical applications, random arrangement of the nanoparticles is often unfavored so that the assembly of gold nanoshells is becoming a central issue. We here proposed to utilize time-variant magnetic field to direct the assembly of gold nanoshells. It was discovered that the alternating magnetic field can mediate the vortex-like assembly of gold nanoshells. The mechanism was explored and thought to be relative with the electric field of induction which caused the thermal gradient on the substrate and the electric force. The vortexlike structure as well as the assembly mechanism will play an important role in research and application of gold nanomaterials.

  6. Pushing/bearing down methods for the second stage of labour.

    PubMed

    Lemos, Andrea; Amorim, Melania M R; Dornelas de Andrade, Armele; de Souza, Ariani I; Cabral Filho, José Eulálio; Correia, Jailson B

    2015-10-09

    Maternal pushing during the second stage of labour is an important and indispensable contributor to the involuntary expulsive force developed by uterus contraction. Currently, there is no consensus on an ideal strategy to facilitate these expulsive efforts and there are contradictory results about the influence on mother and fetus. To evaluate the benefits and possible disadvantages of different kinds of techniques regarding maternal pushing/breathing during the expulsive stage of labour on maternal and fetal outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 January 2015) and reference lists of retrieved studies. Randomised and quasi-randomised assessing the effects of pushing/bearing down techniques (type and/or timing) performed during the second stage of labour on maternal and neonatal outcomes. Cluster-RCTs were eligible for inclusion but none were identified. Studies using a cross-over design and those published in abstract form only were not eligible for inclusion.We considered the following comparisons.Timing of pushing: to compare pushing, which begins as soon as full dilatation has been determined versus pushing which begins after the urge to push is felt.Type of pushing: to compare pushing techniques that involve the 'Valsalva Manoeuvre' versus all other pushing techniques. Two review authors independently assessed trials for inclusion and risk of bias. Two review authors independently extracted data. Data were checked for accuracy. We included 20 studies in total, seven studies (815 women) comparing spontaneous pushing versus directed pushing, with or without epidural analgesia and 13 studies (2879 women) comparing delayed pushing versus immediate pushing with epidural analgesia. The results come from studies with a high or unclear risk of bias, especially selection bias and selective reporting bias. Comparison 1: types of pushing: spontaneous pushing versus directed pushingOverall, for this comparison there was no

  7. Telerobotic truss assembly

    NASA Technical Reports Server (NTRS)

    Sheridan, Philip L.

    1987-01-01

    The ACCESS truss was telerobotically assembled in order to gain experience with robotic assembly of hardware designed for astronaut extravehicular (EVA) assembly. Tight alignment constraints of the ACCESS hardware made telerobotic assembly difficult. A wider alignment envelope and a compliant end effector would have reduced the problem. The manipulator had no linear motion capability, but many of the assembly operations required straight line motion. The manipulator was attached to a motion table in order to provide the X, Y, and Z translations needed. A programmable robot with linear translation capability would have eliminated the need for the motion table and streamlined the assembly. Poor depth perception was a major problem. Shaded paint schemes and alignment lines were helpful in reducing this problem. The four cameras used worked well for only some operations. It was not possible to identify camera locations that worked well for all assembly steps. More cameras or movable cameras would have simplified some operations. The audio feedback system was useful.

  8. Edison Electric, Exxon Push Nuclear Power in Nation's Classrooms

    ERIC Educational Resources Information Center

    Feldman, Dede

    1978-01-01

    Pro-nuclear power "educational materials" designed or promoted by energy and utility companies lack objectivity about alternative energy resources. A free comic book distributed to public schools in New Mexico and a simulation game supplied to Maryland public schools at the expense of utility customers are described. (SW)

  9. Rock pushing and sampling under rocks on Mars

    USGS Publications Warehouse

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    from under a rock to the aqueous nutrient in the Gas Exchange instrument indicates that adsorbed water and hydrates play an important role in the oxidation potential of the soil. The rock surfaces are strong, because they did not scratch, chip or spall when the sampler pushed them. Fresh surfaces of soil and the undersides of rocks were exposed so that they could be imaged in color. A ledge of soil adhered to one rock that tilted, showing that a crust forms near the surface of Mars. The reason for low amounts of iron in the sampIes from under the rocks is not known at this time.

  10. The Effects of Push-ups with the Trunk Flexed on the Shoulder and Trunk Muscles

    PubMed Central

    Kang, Dong-hyun; Jung, So-young; Nam, Dong-hun; Shin, Seung-je; Yoo, Won-gyu

    2014-01-01

    [Purpose] The purpose of this study was to compare the activity of the shoulder and trunk muscles in two push-up positions: standard push-ups and push-ups with the trunk flexed. [Subjects] Fifteen young adult males participated in the study. [Methods] This study measured the clavicular and sternocostal portions of the pectoralis major, the serratus anterior, and the rectus abdominis during push-ups under the two conditions. [Results] The activity of the sternocostal portion of the pectoralis major and that of the rectus abdominis were significantly greater under Condition 1 than under Condition 2. The activity of the clavicular portion of the pectoralis major and that of the serratus anterior were significantly greater under Condition 2 compared with Condition 1. [Conclusion] These results indicate that exercises can selectively activate muscle parts under different clinical situations. PMID:25013294

  11. The Effects of Push-ups with the Trunk Flexed on the Shoulder and Trunk Muscles.

    PubMed

    Kang, Dong-Hyun; Jung, So-Young; Nam, Dong-Hun; Shin, Seung-Je; Yoo, Won-Gyu

    2014-06-01

    [Purpose] The purpose of this study was to compare the activity of the shoulder and trunk muscles in two push-up positions: standard push-ups and push-ups with the trunk flexed. [Subjects] Fifteen young adult males participated in the study. [Methods] This study measured the clavicular and sternocostal portions of the pectoralis major, the serratus anterior, and the rectus abdominis during push-ups under the two conditions. [Results] The activity of the sternocostal portion of the pectoralis major and that of the rectus abdominis were significantly greater under Condition 1 than under Condition 2. The activity of the clavicular portion of the pectoralis major and that of the serratus anterior were significantly greater under Condition 2 compared with Condition 1. [Conclusion] These results indicate that exercises can selectively activate muscle parts under different clinical situations.

  12. Visualization of airflows in push-pull ventilation systems applied to surface treatment tanks.

    PubMed

    Marzal, F; González, E; Miñana, A; Baeza, A

    2003-01-01

    A pilot installation was designed that simulates a surface treatment tank fitted with a push-pull ventilation system. The installation contained elements for measuring and controlling the operational variables (flow rate and tank temperature) and smoke generating equipment for injecting smoke through the holes of the push unit and from the tank surface. Visual observation and video recording of the flows involved meant it was possible to follow the qualitative behavior of the push flow rate along the tank surface and to identify any emissions not captured by the exhaust system. It was possible to differentiate the initial semifree push curtain, its impact with the tank surface, the wall jet that moved toward the exhaust, and its entrance into the exhaust. The methodology proposed is complemented by a quantitative technique for measuring the efficiency, using sulfur hexafluoride as tracer, which permits the causes and location of losses in the ventilation system to be determined.

  13. Digital Material Assembly by Passive Means and Modular Isotropic Lattice Extruder System

    NASA Technical Reports Server (NTRS)

    Carney, Matthew Eli (Inventor); Jenett, Benjamin (Inventor); Gershenfeld, Neil (Inventor)

    2017-01-01

    A set of machines and related systems build structures by the additive assembly of discrete parts. These digital material assemblies constrain the constituent parts to a discrete set of possible positions and orientations. In doing so, the structures exhibit many of the properties inherent in digital communication such as error correction, fault tolerance and allow the assembly of precise structures with comparatively imprecise tools. Assembly of discrete cellular lattices by a Modular Isotropic Lattice Extruder System (MILES) is implemented by pulling strings of lattice elements through a forming die that enforces geometry constraints that lock the elements into a rigid structure that can then be pushed against and extruded out of the die as an assembled, loadbearing structure.

  14. Standardizing Ammunition Distribution within the United States Navy as either a Push or Pull Methodology

    DTIC Science & Technology

    2012-06-01

    4 Figure 2. Push-Pull Boundaries (From Simchi-Levi et al., 2008) .....................................7 Figure 3. Kanban System (After...single unit) constituting what is called a Kanban : the standard lot size calculated for that particular item managed by the pull system. Boundaries...Rogers, 2001). Figure 2. Push-Pull Boundaries (From Simchi-Levi et al., 2008) The Kanban system (see Figure 3) is an example of the pull

  15. A unified perspective on ankle push-off in human walking

    PubMed Central

    Adamczyk, Peter G.

    2016-01-01

    ABSTRACT Muscle–tendon units about the ankle joint generate a burst of positive power during the step-to-step transition in human walking, termed ankle push-off, but there is no scientific consensus on its functional role. A central question embodied in the biomechanics literature is: does ankle push-off primarily contribute to leg swing, or to center of mass (COM) acceleration? This question has been debated in various forms for decades. However, it actually presents a false dichotomy, as these two possibilities are not mutually exclusive. If we ask either question independently, the answer is the same: yes! (1) Does ankle push-off primarily contribute to leg swing acceleration? Yes. (2) Does ankle push-off primarily contribute to COM acceleration? Yes. Here, we summarize the historical debate, then synthesize the seemingly polarized perspectives and demonstrate that both descriptions are valid. The principal means by which ankle push-off affects COM mechanics is by a localized action that increases the speed and kinetic energy of the trailing push-off limb. Because the limb is included in body COM computations, this localized segmental acceleration also accelerates the COM, and most of the segmental energy change also appears as COM energy change. Interpretation of ankle mechanics should abandon an either/or contrast of leg swing versus COM acceleration. Instead, ankle push-off should be interpreted in light of both mutually consistent effects. This unified perspective informs our fundamental understanding of the role of ankle push-off, and has important implications for the design of clinical interventions (e.g. prostheses, orthoses) intended to restore locomotor function to individuals with disabilities. PMID:27903626

  16. Quantifying muscle patterns and spine load during various forms of the push-up.

    PubMed

    Freeman, Stephanie; Karpowicz, Amy; Gray, John; McGill, Stuart

    2006-03-01

    This study was conducted to quantify the normalized amplitudes of the abdominal wall and back extensor musculature during a variety of push-up styles. We also sought to quantify their impact on spinal loading by calculating spinal compression and torque generation in the L4-5 area. Ten university-age participants, nine males and one female, in good to excellent condition, volunteered to participate in this study. All participants were requested to perform a maximum of 12 different push-up exercises, three trials per exercise. Surface electromyographic data (EMG) were collected bilaterally on rectus abdominis, external oblique, internal oblique, latissimus dorsi, and erector spinae muscles, and unilaterally (right side) on pectoralis major, triceps brachii, biceps brachii, and anterior deltoid muscles. Spine kinetics were obtained using an anatomically detailed model of the torso/spine. This study revealed that more dynamic push-ups (i.e., ballistic, with hand movement) required more muscle activation and higher spine load, whereas placing labile balls under the hands only resulted in modest increases in spine load. Right rectus abdominis (RA) activation was significantly higher than left RA activation during the left hand forward push-up and vice versa for the right hand forward push-up (P < 0.001). External oblique (EO) demonstrated the same switch in dominance during staggered hand push-ups (P < 0.01). The one-arm push-up resulted in the highest spine compression. Skilled participants showed greater synchronicity with peak muscle activation (plyometric type of contractions) during ballistic push-ups. These data will help guide exercise selection for individuals with differing training objectives and injury history.

  17. Relative balance of serratus anterior and upper trapezius muscle activity during push-up exercises.

    PubMed

    Ludewig, Paula M; Hoff, Molly S; Osowski, Erin E; Meschke, Shane A; Rundquist, Peter J

    2004-03-01

    Serratus anterior strengthening is used in prevention and treatment programs for poor scapular control. In certain clinical cases, exercises substantially activating the serratus with minimal upper trapezius activation are preferred. The standard push-up plus would show both the highest serratus anterior activation and lowest upper trapezius/ serratus ratios for both groups and all phases. Controlled laboratory study. Thirty subjects, grouped as healthy or with mild shoulder dysfunction, were evaluated performing standard push-up plus exercises and modifications on elbows, knees, and against a wall. Surface electromyography of the serratus anterior and upper trapezius was compared between exercises. Both groups responded similarly across exercises. The standard push-up plus demonstrated the highest activation of the serratus (to 123%) and lowest trapezius/serratus ratios (<0.2) during plus phases. The wall push-up plus and phases of other exercises demonstrated higher upper trapezius/serratus ratios (to 2.0). In clinical cases where excess upper trapezius activation or imbalance of serratus and trapezius activation occurs, the push-up plus is an optimal exercise. Other cases may benefit from a progression of modified push-up exercises. Clinical selection of exercises for improving scapular control should consider both maximum serratus activation and upper trapezius/serratus anterior ratios.

  18. Effect of the push-up exercise at different palmar width on muscle activities

    PubMed Central

    Kim, You-Sin; Kim, Do-Yeon; Ha, Min-Seong

    2016-01-01

    [Purpose] The purpose of the present study was to determine the effects of changes in palmar width on the muscle activities of the shoulder and truncus muscles during push-up exercise. [Subjects] Twelve healthy adult males participated in this study as subjects. [Methods] Push-up exercises were performed with three different palmar width in narrow (50%), neutral (100%), and wide positions (150%). We measured the muscle activities of the deltoideus p. acromialis, pectoralis minor, pectoralis major, serratus anterior, biceps brachii, triceps brachii, latissimus dorsi, and infraspinatus. [Results] Pectoralis minor, triceps brachii, and infraspinatus muscle activities were greater during push-ups performed with the 50% palmar width compared with the other palmar widths. Pectoralis major muscle activity was greater during push-ups performed with the 50% and 100% palmar widths compared with the 150% palmar width. Serratus anterior muscle activity was greater during push-ups performed with the 150% palmar width compared with the other palmar widths. [Conclusion] These results are expected to serve as reference materials for push-up exercise applications in training programs for truncus muscle strengthening or rehabilitation programs for scapula patients. PMID:27064571

  19. Effect of Progressive Calisthenic Push-up Training on Muscle Strength and Thickness.

    PubMed

    Kotarsky, Christopher J; Christensen, Bryan K; Miller, Jason S; Hackney, Kyle J

    2018-03-01

    Kotarsky, CJ, Christensen, BK, Miller, JS, and Hackney, KJ. Effect of progressive calisthenic push-up training on muscle strength and thickness. J Strength Cond Res 32(3): 651-659, 2018-Calisthenics, a form of resistance training, continue to increase in popularity; however, few studies have examined their effectiveness for muscle strength improvement. The purpose of this study was to determine whether progressive calisthenic push-up training (PUSH) is comparable with traditional bench press training (BENCH) as a technique for increasing muscle strength and thickness. Twenty-three healthy, moderately trained men (mean ± SD: age 23 ± 6.8 years) completed the study. Subjects were randomly assigned to PUSH (n = 14) and BENCH (n = 9) groups and were trained 3 days per week for 4 weeks. Muscle thickness (MT), seated medicine ball put (MBP), 1 repetition maximum (1RM) bench press, and push-up progression (PUP) were measured before and after training. Results revealed significant increases in 1RM (p < 0.001) and PUP (p < 0.001) for both groups after training. The increase in PUP was significantly greater for PUSH (p < 0.001). No significant differences were found within groups for MT and MBP (p > 0.05). This study is the first to demonstrate that calisthenics, using different progressive variations to maintain strength training programming variables, can improve upper-body muscle strength.

  20. The pull-up spreader high (PUSH) technique for nasal tip support.

    PubMed

    Bertossi, Dario; Walter, Claus; Nocini, Pier Francesco

    2014-11-01

    Nasal tip depression is associated with nasal valve collapse. The pull-up spreader high (PUSH) technique was developed to enlarge the nasal dorsum and upwardly rotate and define the nasal tip by lifting the domes. The authors reviewed a case series to assess the long-term effectiveness of the PUSH technique in improving nasal airflow and aesthetic outcomes. This retrospective study included 50 consecutive cases of PUSH rhinoplasty. Objective (acoustic rhinomanometry) and subjective (patient questionnaire) evaluations of the stability of the aesthetic result and improvement of airflow were conducted before and 3 years after PUSH rhinoplasty. PUSH rhinoplasty resulted in long-term stability of the aesthetic effect. All patients had pleasing aesthetic results and a general improvement in the nasal airway. When the degree of nasal obstruction was scored from 1 (greatest obstruction) to 10 (least obstruction), 22 patients rated their nasal function improved to a score of 10 and 28 patients to a score of 8. Rhinomanometry indicated that only 1 patient had worsened nasal airflow. The PUSH technique enables stable upward rotation and improved definition of the severely depressed nasal tip through an open approach. 4. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

  1. Alternative Conceptualizations.

    ERIC Educational Resources Information Center

    Borman, Kathryn M., Ed.; O'Reilly, Patricia, Ed.

    1992-01-01

    This theme issue of the serial "Educational Foundations" contains five articles devoted to the topic of "Alternative Conceptualizations" of the foundations of education. In "The Concept of Place in the New Sociology of Education," Paul Theobald examines the notion of place in educational theory and practice. Janice…

  2. Magnetostrictive Alternator

    NASA Technical Reports Server (NTRS)

    Dyson, Rodger; Bruder, Geoffrey

    2013-01-01

    This innovation replaces the linear alternator presently used in Stirling engines with a continuous-gradient, impedance-matched, oscillating magnetostrictive transducer that eliminates all moving parts via compression, maintains high efficiency, costs less to manufacture, reduces mass, and eliminates the need for a bearing system. The key components of this new technology are the use of stacked magnetostrictive materials, such as Terfenol-D, under a biased magnetic and stress-induced compression, continuous-gradient impedance-matching material, coils, force-focusing metallic structure, and supports. The acoustic energy from the engine travels through an impedancematching layer that is physically connected to the magnetostrictive mass. Compression bolts keep the structure under compressive strain, allowing for the micron-scale compression of the magnetostrictive material and eliminating the need for bearings. The relatively large millimeter displacement of the pressure side of the impedance-matching material is reduced to micron motion, and undergoes stress amplification at the magnetostrictive interface. The alternating compression and expansion of the magnetostrictive material creates an alternating magnetic field that then induces an electric current in a coil that is wound around the stack. This produces electrical power from the acoustic pressure wave and, if the resonant frequency is tuned to match the engine, can replace the linear alternator that is commonly used.

  3. Alternative Thinking.

    ERIC Educational Resources Information Center

    Herman, Dan

    1999-01-01

    Explains how advances in diesel and alternative fuels has caused schools to reconsider their use for their bus fleets. Reductions in air pollution emissions, cost-savings developments, and the economies experienced from less downtime and maintenance requirements are explored. (GR)

  4. Spontaneous Pushing in Lateral Position versus Valsalva Maneuver During Second Stage of Labor on Maternal and Fetal Outcomes: A Randomized Clinical Trial.

    PubMed

    Vaziri, Farideh; Arzhe, Amene; Asadi, Nasrin; Pourahmad, Saeedeh; Moshfeghy, Zeinab

    2016-10-01

    There are concerns about the harmful effects of the Valsalva maneuver during the second stage of labor. Comparing the effects of spontaneous pushing in the lateral position with the Valsalva maneuver during the second stage of labor on maternal and fetal outcomes. Inclusion criteria in this randomized clinical trial conducted in Iran were as follows: nulliparous mothers, live fetus with vertex presentation, gestational age of 37 - 40 weeks, spontaneous labor, and no complications. The intervention group pushed spontaneously while they were in the lateral position, whereas the control group pushed using Valsalva method while in the supine position at the onset of the second stage of labor. Maternal outcomes such as pain and fatigue severity and fetal outcomes such as pH and pO2 of the umbilical cord blood were measured. Data pertaining to 69 patients, divided into the intervention group (35 subjects) and control group (34 subjects), were analyzed statistically. The mean pain (7.80 ± 1.21 versus 9.05 ± 1.11) and fatigue scores (46.59 ± 21 versus 123.36 ± 43.20) of the two groups showed a statistically significant difference (P < 0.001). Moreover, the mean duration of the second stage in the intervention group was significantly higher than that in the control group (76.32 ± 8.26 minutes versus 64.56 ± 15.24 minutes, P = 0.001). The umbilical cord blood pO 2 levels of both groups showed a statistically significant difference (28.29 ± 11.76 versus 18.83 ± 9.86, P < 0.001), whereas their pH levels were not significantly different (P = 0.10). Spontaneous pushing in the lateral position reduced fatigue and pain severity of the mothers. Also, it did not worsen fetal outcomes. Thus, it can be used as an alternative method for the Valsalva maneuver.

  5. A low-phase-noise Ka-band push-push voltage-controlled oscillator using CMOS/glass-integrated passive device technologies.

    PubMed

    Wang, Sen

    2014-09-01

    In this paper, a Ka-band CMOS push-push voltage- controlled oscillator (VCO) integrated into a glass-integrated passive device (GIPD) process is presented. The transformer, λ/4 transmission line, and inductors of the VCO are realized in the GIPD process, achieving superior performances, and therefore improve the phase noise of the VCO. Moreover, the transformer-based VCO is a differential Hartley topology to further reduce the phase noise and chip area. Operating at 1.8 V supply voltage, the VCO core consumes merely 3.8 mW of dc power. The measured phase noise is -109.18 dBc/Hz at 1 MHz offset from the 30.84 GHz oscillation frequency. The push-push VCO also demonstrates a 24.5 dB fundamental rejection, and exhibits an 8.4% tuning range. Compared with recently published CMOS-based VCOs, it is observed that the proposed VCO exhibits excellent performance under low power consumption.

  6. Autonomous electrochromic assembly

    SciTech Connect

    Berland, Brian Spencer; Lanning, Bruce Roy; Stowell, Jr., Michael Wayne

    2015-03-10

    This disclosure describes system and methods for creating an autonomous electrochromic assembly, and systems and methods for use of the autonomous electrochromic assembly in combination with a window. Embodiments described herein include an electrochromic assembly that has an electrochromic device, an energy storage device, an energy collection device, and an electrochromic controller device. These devices may be combined into a unitary electrochromic insert assembly. The electrochromic assembly may have the capability of generating power sufficient to operate and control an electrochromic device. This control may occur through the application of a voltage to an electrochromic device to change its opacitymore » state. The electrochromic assembly may be used in combination with a window.« less

  7. Chitosan biotinylation and electrodeposition for selective protein assembly.

    PubMed

    Shi, Xiao-Wen; Liu, Yi; Lewandowski, Angela T; Wu, Li-Qun; Wu, Hsuan-Chen; Ghodssi, Reza; Rubloff, Gary W; Bentley, William E; Payne, Gregory F

    2008-05-13

    An alternative route to protein assembly at surfaces based on using the unique capabilities of biological materials for the spatially selective assembly of proteins is described. Specifically, the stimuli-responsive properties of aminopolysaccharide chitosan are combined with the molecular-recognition capabilities of biotin-streptavidin binding. Biotinylated chitosan retains its stimuli-responsive properties and is capable of electrodepositing at specific electrode addresses. Once deposited, it is capable of binding streptavidin, which can mediate the subsequent assembly of biotinylated proteins. Spatially selective protein assembly using biotinylated Protein A and fluorescently-labeled antibodies is demonstrated.

  8. Composite turbine bucket assembly

    DOEpatents

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  9. Sensor mount assemblies and sensor assemblies

    SciTech Connect

    Miller, David H

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and themore » tooth is formed on the second end of the first finger.« less

  10. 60K Fastrac Thrust Chamber Assembly Test

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This double exposure depicts Marshall Space Flight Center's (MSFC) Test Stand 116 hosting a 60K Bantam Fastrac thrust chamber assembly test. The lower right exposure shows the engine firing in the test stand while the center exposure reveals workers monitoring the test in the interior block house of the test facility. The thrust chamber assembly is only part of the Fastrac engine project to build a low-cost engine for the X-34, an alternate light-weight unmarned launch vehicle. Both the nozzle and the engine for Fastrac are being manufactured at MSFC.

  11. Cleaning solvent substitution in electronic assemblies

    SciTech Connect

    Meier, G.J.

    1993-09-01

    Alternatives to chlorinated and fluorinated solvents have been identified, qualified, and implemented into production of complex electronic assemblies. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, has been selected as the solvent of choice for cleaning complex electronic assemblies, and has been found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data.

  12. Alternative polyadenylation

    PubMed Central

    Xing, Denghui

    2009-01-01

    Based on comparative genome analyses, the increases in protein-coding gene number could not account for the increases of morphological and behavioral complexity of higher eukaryotes. Transcriptional regulations, alternative splicing and the involvement of non-coding RNA in gene expression regulations have been credited for the drastic increase of transcriptome complexity. However, an emerging theme of another mechanism that contributes to the formation of alternative mRNA 3′-ends is alternative polyadenylation (APA). First, recent studies indicated that APA is a wide spread phenomenon across the transcriptomes of higher eukaryotes and being regulated by developmental and environmental cues. Secondly, our characterization of the Arabidopsis polyadenylation factors suggested that plant polyadenylation has also evolved to regulate the expression of specific genes by means of APA and therefore the specific biological functions. Finally, Phylogenetic analyses of eukaryotic polyadenylation factors from several organisms revealed that the number of polyadenylation factors tends to increase in higher eukaryotes, which provides the potential for their functional differentiation in regulating gene expression through APA. Based on above evidence, we, thus, hypothesize that APA, serving as an additional mechanism, contributes to the complexity of higher eukaryotes. PMID:19816115

  13. Critical evaluation of the push-out test for root canal filling materials.

    PubMed

    Pane, Epita S; Palamara, Joseph E A; Messer, Harold H

    2013-05-01

    The push-out test has been widely used in experimental endodontics but has been criticized on technical grounds particularly because the soft-core material undergoes plastic deformation under load. This study systematically evaluated the technique by comparing push-out strength and load profiles in relation to core material stiffness, canal diameter, punch diameter, sample orientation, and mode of failure. Straight palatal roots of 90 maxillary molars were obturated with an epoxy resin-based sealer alone (10 roots) or gutta-percha (70) or epoxy resin (10) cores with a thin layer of sealer cement. Roots were embedded in mounting resin vertically or at an angle of 5° or 10° to the long axis of the root. One-millimeter sections were tested using a universal testing machine with a punch diameter corresponding to 50%, 75%, or 90% of the canal diameter. Bond strengths (MPa) were calculated, and data were analyzed using analysis of variance with post hoc Tukey multiple comparisons (P < .05). After push out, core materials and canal walls were examined using scanning electron microscopy. Push-out strength was affected by core material stiffness. Angulation up to 10° from vertical had little effect on push-out strength, but load profiles were strongly influenced by orientation. No effect of the punch diameter was observed when the diameter was 90% of the canal diameter, but push-out strength was lower when the punch diameter was 50%-60% of the canal size. Despite limitations, the push-out test may still be suitable for ranking the bonding of root filling materials. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Sequential Push-Pull Pumping Mechanism for Washing and Evacuation of an Immunoassay Reaction Chamber on a Microfluidic CD Platform

    PubMed Central

    Thio, Tzer Hwai Gilbert; Ibrahim, Fatimah; Al-Faqheri, Wisam; Soin, Norhayati; Kahar Bador, Maria; Madou, Marc

    2015-01-01

    A centrifugal compact disc (CD) microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP) Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes. PMID:25853411

  15. Sequential push-pull pumping mechanism for washing and evacuation of an immunoassay reaction chamber on a microfluidic CD platform.

    PubMed

    Thio, Tzer Hwai Gilbert; Ibrahim, Fatimah; Al-Faqheri, Wisam; Soin, Norhayati; Kahar Bador, Maria; Madou, Marc

    2015-01-01

    A centrifugal compact disc (CD) microfluidic platform with reservoirs, micro-channels, and valves can be employed for implementing a complete immunoassay. Detection or biosensor chambers are either coated for immuno-interaction or a biosensor chip is inserted in them. On microfluidic CDs featuring such multi-step chemical/biological processes, the biosensor chamber must be repeatedly filled with fluids such as enzymes solutions, buffers, and washing solutions. After each filling step, the biosensor chamber needs to be evacuated by a passive siphoning process to prepare it for the next step in the assay. However, rotational speed dependency and limited space on a CD are two big obstacles to performing such repetitive filling and siphoning steps. In this work, a unique thermo-pneumatic (TP) Push-Pull pumping method is employed to provide a superior alternative biosensor chamber filling and evacuation technique. The proposed technique is demonstrated on two CD designs. The first design features a simple two-step microfluidic process to demonstrate the evacuation technique, while the second design shows the filling and evacuation technique with an example sequence for an actual immunoassay. In addition, the performance of the filling and evacuation technique as a washing step is also evaluated quantitatively and compared to the conventional manual bench top washing method. The two designs and the performance evaluation demonstrate that the technique is simple to implement, reliable, easy to control, and allows for repeated push-pulls and thus filling and emptying of the biosensor chamber. Furthermore, by addressing the issue of rotational speed dependency and limited space concerns in implementing repetitive filling and evacuation steps, this newly introduced technique increases the flexibility of the microfluidic CD platform to perform multi-step biological and chemical processes.

  16. Laser bottom hole assembly

    DOEpatents

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  17. Pultrusion Die Assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L. (Inventor); Johnson, Gary S. (Inventor); Frye, Mark W. (Inventor); Stanfield, Clarence E. (Inventor)

    1988-01-01

    This invention relates generally to pultrusion die assemblies, and more particularly, to a pultrusion die assembly which incorporates a plurality of functions in order to produce a continuous, thin composite fiber reinforced thermoplastic material. The invention is useful for making high performance thermoplastic composite materials in sheets which can be coiled on a spool and stored for further processing.

  18. Assembling Transgender Moments

    ERIC Educational Resources Information Center

    Greteman, Adam J.

    2017-01-01

    In this article, the author seeks to assemble moments--scholarly, popular, and aesthetic--in order to explore the possibilities that emerge as moments collect in education's encounters with the needs, struggles, and possibilities of transgender lives and practices. Assembling moments, the author argues, illustrates the value of "moments"…

  19. Liquid rocket valve assemblies

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The design and operating characteristics of valve assemblies used in liquid propellant rocket engines are discussed. The subjects considered are as follows: (1) valve selection parameters, (2) major design aspects, (3) design integration of valve subassemblies, and (4) assembly of components and functional tests. Information is provided on engine, stage, and spacecraft checkout procedures.

  20. Turbine disc sealing assembly

    DOEpatents

    Diakunchak, Ihor S.

    2013-03-05

    A disc seal assembly for use in a turbine engine. The disc seal assembly includes a plurality of outwardly extending sealing flange members that define a plurality of fluid pockets. The sealing flange members define a labyrinth flow path therebetween to limit leakage between a hot gas path and a disc cavity in the turbine engine.

  1. Permanent magnet assembly

    DOEpatents

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

    A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

  2. Perspective: Geometrically frustrated assemblies

    NASA Astrophysics Data System (ADS)

    Grason, Gregory M.

    2016-09-01

    This perspective will overview an emerging paradigm for self-organized soft materials, geometrically frustrated assemblies, where interactions between self-assembling elements (e.g., particles, macromolecules, proteins) favor local packing motifs that are incompatible with uniform global order in the assembly. This classification applies to a broad range of material assemblies including self-twisting protein filament bundles, amyloid fibers, chiral smectics and membranes, particle-coated droplets, curved protein shells, and phase-separated lipid vesicles. In assemblies, geometric frustration leads to a host of anomalous structural and thermodynamic properties, including heterogeneous and internally stressed equilibrium structures, self-limiting assembly, and topological defects in the equilibrium assembly structures. The purpose of this perspective is to (1) highlight the unifying principles and consequences of geometric frustration in soft matter assemblies; (2) classify the known distinct modes of frustration and review corresponding experimental examples; and (3) describe outstanding questions not yet addressed about the unique properties and behaviors of this broad class of systems.

  3. High speed door assembly

    DOEpatents

    Shapiro, Carolyn

    1993-01-01

    A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  4. High speed door assembly

    DOEpatents

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  5. The push-pull tactic for mitigation of mountain pine beetle (Coleoptera: Curculionidae) damage in lodgepole and whitebark pines.

    PubMed

    Gillette, Nancy E; Mehmel, Constance J; Mori, Sylvia R; Webster, Jeffrey N; Wood, David L; Erbilgin, Nadir; Owen, Donald R

    2012-12-01

    In an attempt to improve semiochemical-based treatments for protecting forest stands from bark beetle attack, we compared push-pull versus push-only tactics for protecting lodgepole pine (Pinus contorta Douglas ex Loudon) and whitebark pine (Pinus albicaulis Engelm.) stands from attack by mountain pine beetle (Dendroctonus ponderosae Hopkins) in two studies. The first was conducted on replicated 4.04-ha plots in lodgepole pine stands (California, 2008) and the second on 0.81-ha plots in whitebark pine stands (Washington, 2010). In both studies, D. ponderosae population levels were moderate to severe. The treatments were 1) push-only (D. ponderosae antiaggregant semiochemicals alone); 2) push-pull (D. ponderosae antiaggregants plus perimeter traps placed at regular intervals, baited with four-component D. ponderosae aggregation pheromone); and 3) untreated controls. We installed monitoring traps baited with two-component D. ponderosae lures inside each plot to assess effect of treatments on beetle flight. In California, fewer beetles were collected in push-pull treated plots than in control plots, but push-only did not have a significant effect on trap catch. Both treatments significantly reduced the rate of mass and strip attacks by D. ponderosae, but the difference in attack rates between push-pull and push-only was not significant. In Washington, both push-pull and push-only treatments significantly reduced numbers of beetles caught in traps. Differences between attack rates in treated and control plots in Washington were not significant, but the push-only treatment reduced attack rates by 30% compared with both the control and push-pull treatment. We conclude that, at these spatial scales and beetle densities, push-only may be preferable for mitigating D. ponderosae attack because it is much less expensive, simpler, and adding trap-out does not appear to improve efficacy.

  6. Second thoughts on septation by the fission yeast, Schizosaccharomyces pombe: pull vs. push mechanisms with an appendix--dimensional modelling of the flat and variable septa.

    PubMed

    Johnson, Byron F; Yoo, Bong Y; Calleja, Gode B; Kozela, Christopher P

    2005-07-01

    The correlation of contraction by an actomyosin band with the closing of the septum of dividing cells of the fission yeast, Schizosaccharomyces pombe, cannot suggest cause-and-effect because contraction would be apparent whether the membrane enveloping the centripetally closing septum were pulled or were pushed. Thus the common observation of contraction is not critical. Diagrams of published electron micrographs of dividing wild-type fission yeasts illustrate variable (tilted) septal images that are counterintuitive to a pull model. Circumference calculations based on those images suggest that some variable forms might be only 6% closed even though their two-dimensional profiles would be 50% closed, if they were not tilted. Development of multiseptate forms of cdc4-8 and cdc4-377 temperature sensitive mutants incubated at their restrictive temperature was followed. These multiseptate forms are shown to have functional (functional in terms of generating divided uninucleate cytoplasts) but grotesque septa which are formed in the absence of actomyosin bands. By contrast, the myosin of the plant phragmoplast is not properly oriented for contractility, and Dictyostelium (attached cells) and Saccharomyces (mutants) have been shown to divide in the absence of myosin II, just as S. pombe does (above). Hence contractility, the essence of a pull model for septum closure, would seem to be non-essential. Other, non-contractile mechanisms of myosin are emphasized, and a push model becomes a rational default hypothesis. The essence of push models is that their synthesis/assembly mechanisms are driving force sufficient for septum closure.

  7. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  8. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  9. Modeling Viral Capsid Assembly

    PubMed Central

    2014-01-01

    I present a review of the theoretical and computational methodologies that have been used to model the assembly of viral capsids. I discuss the capabilities and limitations of approaches ranging from equilibrium continuum theories to molecular dynamics simulations, and I give an overview of some of the important conclusions about virus assembly that have resulted from these modeling efforts. Topics include the assembly of empty viral shells, assembly around single-stranded nucleic acids to form viral particles, and assembly around synthetic polymers or charged nanoparticles for nanotechnology or biomedical applications. I present some examples in which modeling efforts have promoted experimental breakthroughs, as well as directions in which the connection between modeling and experiment can be strengthened. PMID:25663722

  10. Mechanisms of Virus Assembly

    PubMed Central

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-01-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid, and in some cases surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assembles within their host cells and in vitro. We describe the thermodynamics and kinetics for assembly of protein subunits into icosahedral capsid shells, and how these are modified in cases where the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques that have been used to characterize capsid assembly, and we highlight aspects of virus assembly which are likely to receive significant attention in the near future. PMID:25532951

  11. Automated assembly in space

    NASA Technical Reports Server (NTRS)

    Srivastava, Sandanand; Dwivedi, Suren N.; Soon, Toh Teck; Bandi, Reddy; Banerjee, Soumen; Hughes, Cecilia

    1989-01-01

    The installation of robots and their use of assembly in space will create an exciting and promising future for the U.S. Space Program. The concept of assembly in space is very complicated and error prone and it is not possible unless the various parts and modules are suitably designed for automation. Certain guidelines are developed for part designing and for an easy precision assembly. Major design problems associated with automated assembly are considered and solutions to resolve these problems are evaluated in the guidelines format. Methods for gripping and methods for part feeding are developed with regard to the absence of gravity in space. The guidelines for part orientation, adjustments, compliances and various assembly construction are discussed. Design modifications of various fasteners and fastening methods are also investigated.

  12. Constrained space camera assembly

    DOEpatents

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  13. Community Wind: Once Again Pushing the Envelope of Project Finance

    SciTech Connect

    bolinger, Mark A.

    2011-01-18

    In the United States, the 'community wind' sector - loosely defined here as consisting of relatively small utility-scale wind power projects that sell power on the wholesale market and that are developed and owned primarily by local investors - has historically served as a 'test bed' or 'proving grounds' for up-and-coming wind turbine manufacturers that are trying to break into the U.S. wind power market. For example, community wind projects - and primarily those located in the state of Minnesota - have deployed the first U.S. installations of wind turbines from Suzlon (in 2003), DeWind (2008), Americas Wind Energy (2008)more » and later Emergya Wind Technologies (2010), Goldwind (2009), AAER/Pioneer (2009), Nordic Windpower (2010), Unison (2010), and Alstom (2011). Thus far, one of these turbine manufacturers - Suzlon - has subsequently achieved some success in the broader U.S. wind market as well. Just as it has provided a proving grounds for new turbines, so too has the community wind sector served as a laboratory for experimentation with innovative new financing structures. For example, a variation of one of the most common financing arrangements in the U.S. wind market today - the special allocation partnership flip structure (see Figure 1 in Section 2.1) - was first developed by community wind projects in Minnesota more than a decade ago (and is therefore sometimes referred to as the 'Minnesota flip' model) before being adopted by the broader wind market. More recently, a handful of community wind projects built over the past year have been financed via new and creative structures that push the envelope of wind project finance in the U.S. - in many cases, moving beyond the now-standard partnership flip structures involving strategic tax equity investors. These include: (1) a 4.5 MW project in Maine that combines low-cost government debt with local tax equity, (2) a 25.3 MW project in Minnesota using a sale/leaseback structure, (3) a 10.5 MW project in South

  14. Alternative Operational Energy Options - A Need for a Holistic Approach to Reduce the Logistics Tail and Improve Strategic Advantage

    DTIC Science & Technology

    2015-02-18

    CHAPTER 1 FUEL CELLS ................................................................................................6 CHAPTER 2 WIND POWER...overview of fuel cell, wind power, solar power, and micro energy harvesting as potential viable alternative operational energy technologies. Chapter...hydrogen. The overall push is to combine alternative operational energy systems including solar or wind power with the technology to create an onboard

  15. Alternative fuels

    NASA Technical Reports Server (NTRS)

    Grobman, J. S.; Butze, H. F.; Friedman, R.; Antoine, A. C.; Reynolds, T. W.

    1977-01-01

    Potential problems related to the use of alternative aviation turbine fuels are discussed and both ongoing and required research into these fuels is described. This discussion is limited to aviation turbine fuels composed of liquid hydrocarbons. The advantages and disadvantages of the various solutions to the problems are summarized. The first solution is to continue to develop the necessary technology at the refinery to produce specification jet fuels regardless of the crude source. The second solution is to minimize energy consumption at the refinery and keep fuel costs down by relaxing specifications.

  16. Synthesis and Spectroscopic Investigation of a Series of Push-Pull Boron Dipyrromethenes (BODIPYs).

    PubMed

    Xuan, Sunting; Zhao, Ning; Ke, Xiangyi; Zhou, Zehua; Fronczek, Frank R; Kadish, Karl M; Smith, Kevin M; Vicente, M Graça H

    2017-03-03

    A series of push-pull BODIPYs bearing multiple electron-donating and electron-acceptor groups were synthesized regioselectively from 2,3,5,6,8-pentachloro-BODIPY, and characterized by NMR spectroscopy, HRMS, and X-ray crystallography. The influence of the push-pull substituents on the spectroscopic and electrochemical properties of BODIPYs was investigated. Bathochromic shifts were observed for both absorbance (up to 37 nm) and emission (up to 60 nm) in different solvents upon introduction of the push-pull moieties. DFT calculations, consistent with the spectroscopic and cyclic voltammetry studies, show decreased HOMO-LUMO energy gaps upon the installation of the push-pull moieties. BODIPY 7 bearing thienyl groups on the 2 and 6 positions showed the largest λ max for both absorption (635-653 nm) and emission (706-707 nm), but also the lowest fluorescence quantum yields. All BODIPYs were nontoxic in the dark (IC 50 > 200 μM) and showed low phototoxicity (IC 50 > 100 μM, 1.5 J/cm 2 ) toward human HEp2 cells. Despite the relatively low fluorescence quantum yields, the push-pull BODIPYS were effective for cell imaging, readily accumulating within cells and localizing mainly in the ER and Golgi. Our structure-property studies can guide future design of functionalized BODIPYs for various applications, including bioimaging and in dye-sensitized solar cells.

  17. Design and analysis of push-broom optical camera's following windows

    NASA Astrophysics Data System (ADS)

    Chen, Su; Wang, Hu; Xue, Yaoke; Liu, Meiying; Wang, Lingguang

    2017-10-01

    In order to solve the problem of push-broom optical camera's imagery quality difficult to content request which windows size is too large, the author proposed a kind of project for camera's following windows. The author analysed the characteristic of the push-broom optical camera's windows, and proposed the ideal model of the push-broom optical camera's windows. Simultaneously, analyzed the transformational rule of the windows' location and size in the ideal condition. The author proposed the design project of the push-broom optical camera's following windows according to the result of the ideal windows' analysis, and performed an analysis of kinematics simultaneously. Finally, the author designed and analyzed kinematics for the following windows in allusion to a certain push-broom optical camera. According the analysis result, this project could decrease a half size of the light opening area compare with the current technique. It could decrease the stray light's influence of the camera's imagery quality, the following windows move smoothly, and this project could be satisfied to the requirements of engineering use.

  18. Push-me-pull-you: how microtubules organize the cell interior

    PubMed Central

    2008-01-01

    Dynamic organization of the cell interior, which is crucial for cell function, largely depends on the microtubule cytoskeleton. Microtubules move and position organelles by pushing, pulling, or sliding. Pushing forces can be generated by microtubule polymerization, whereas pulling typically involves microtubule depolymerization or molecular motors, or both. Sliding between a microtubule and another microtubule, an organelle, or the cell cortex is also powered by molecular motors. Although numerous examples of microtubule-based pushing and pulling in living cells have been observed, it is not clear why different cell types and processes employ different mechanisms. This review introduces a classification of microtubule-based positioning strategies and discusses the efficacy of pushing and pulling. The positioning mechanisms based on microtubule pushing are efficient for movements over small distances, and for centering of organelles in symmetric geometries. Mechanisms based on pulling, on the other hand, are typically more elaborate, but are necessary when the distances to be covered by the organelles are large, and when the geometry is asymmetric and complex. Thus, taking into account cell geometry and the length scale of the movements helps to identify general principles of the intracellular layout based on microtubule forces. PMID:18404264

  19. Pushing versus pulling: division of labour between tarsal attachment pads in cockroaches.

    PubMed

    Clemente, Christofer J; Federle, Walter

    2008-06-07

    Adhesive organs on the legs of arthropods and vertebrates are strongly direction dependent, making contact only when pulled towards the body but detaching when pushed away from it. Here we show that the two types of attachment pads found in cockroaches (Nauphoeta cinerea), tarsal euplantulae and pretarsal arolium, serve fundamentally different functions. Video recordings of vertical climbing revealed that euplantulae are almost exclusively engaged with the substrate when legs are pushing, whereas arolia make contact when pulling. Thus, upward-climbing cockroaches used front leg arolia and hind leg euplantulae, whereas hind leg arolia and front leg euplantulae were engaged during downward climbing. Single-leg friction force measurements showed that the arolium and euplantulae have an opposite direction dependence. Euplantulae achieved maximum friction when pushed distally, whereas arolium forces were maximal during proximal pulls. This direction dependence was not explained by the variation of shear stress but by different contact areas during pushing or pulling. The changes in contact area result from the arrangement of the flexible tarsal chain, tending to detach the arolium when pushing and to peel off euplantulae when in tension. Our results suggest that the euplantulae in cockroaches are not adhesive organs but 'friction pads', mainly providing the necessary traction during locomotion.

  20. Pushing versus pulling: division of labour between tarsal attachment pads in cockroaches

    PubMed Central

    Clemente, Christofer J; Federle, Walter

    2008-01-01

    Adhesive organs on the legs of arthropods and vertebrates are strongly direction dependent, making contact only when pulled towards the body but detaching when pushed away from it. Here we show that the two types of attachment pads found in cockroaches (Nauphoeta cinerea), tarsal euplantulae and pretarsal arolium, serve fundamentally different functions. Video recordings of vertical climbing revealed that euplantulae are almost exclusively engaged with the substrate when legs are pushing, whereas arolia make contact when pulling. Thus, upward-climbing cockroaches used front leg arolia and hind leg euplantulae, whereas hind leg arolia and front leg euplantulae were engaged during downward climbing. Single-leg friction force measurements showed that the arolium and euplantulae have an opposite direction dependence. Euplantulae achieved maximum friction when pushed distally, whereas arolium forces were maximal during proximal pulls. This direction dependence was not explained by the variation of shear stress but by different contact areas during pushing or pulling. The changes in contact area result from the arrangement of the flexible tarsal chain, tending to detach the arolium when pushing and to peel off euplantulae when in tension. Our results suggest that the euplantulae in cockroaches are not adhesive organs but ‘friction pads’, mainly providing the necessary traction during locomotion. PMID:18331984

  1. Pushing/bearing down methods for the second stage of labour.

    PubMed

    Lemos, Andrea; Amorim, Melania Mr; Dornelas de Andrade, Armele; de Souza, Ariani I; Cabral Filho, José Eulálio; Correia, Jailson B

    2017-03-26

    Maternal pushing during the second stage of labour is an important and indispensable contributor to the involuntary expulsive force developed by uterine contraction. There is no consensus on an ideal strategy to facilitate these expulsive efforts and there are contradictory results about the influence on the mother and fetus. To evaluate the benefits and possible disadvantages of different kinds of techniques regarding maternal pushing/breathing during the expulsive stage of labour on maternal and fetal outcomes. We searched Cochrane Pregnancy and Childbirth's Trials Register (19 September 2016) and reference lists of retrieved studies. Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of pushing/bearing down techniques (type and/or timing) performed during the second stage of labour on maternal and neonatal outcomes. Cluster-RCTs were eligible for inclusion, but none were identified. Studies using a cross-over design and those published in abstract form only were not eligible for inclusion in this review. Two review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. Data were checked for accuracy. In this updated review, we included 21 studies in total, eight (884 women) comparing spontaneous pushing versus directed pushing, with or without epidural analgesia and 13 (2879 women) comparing delayed pushing versus immediate pushing with epidural analgesia. Our GRADE assessments of evidence ranged from moderate to very low quality; the main reasons for downgrading were study design limitations and imprecision of effect estimates. Overall, the included studies varied in their risk of bias; most were judged to be at unclear risk of bias. Comparison 1: types of pushing: spontaneous pushing versus directed pushingThere was no clear difference in the duration of the second stage of labour (mean difference (MD) 10.26 minutes; 95% confidence interval (CI) -1.12 to 21.64 minutes, six studies, 667 women, random

  2. Push-pull tracer tests: Their information content and use for characterizing non-Fickian, mobile-immobile behavior: INFORMATION CONTENT OF PUSH-PULL TESTS

    DOE PAGES

    Hansen, Scott K.; Berkowitz, Brian; Vesselinov, Velimir V.; ...

    2016-12-01

    Path reversibility and radial symmetry are often assumed in push-pull tracer test analysis. In reality, heterogeneous flow fields mean that both assumptions are idealizations. In this paper, to understand their impact, we perform a parametric study which quantifies the scattering effects of ambient flow, local-scale dispersion, and velocity field heterogeneity on push-pull breakthrough curves and compares them to the effects of mobile-immobile mass transfer (MIMT) processes including sorption and diffusion into secondary porosity. We identify specific circumstances in which MIMT overwhelmingly determines the breakthrough curve, which may then be considered uninformative about drift and local-scale dispersion. Assuming path reversibility, wemore » develop a continuous-time-random-walk-based interpretation framework which is flow-field-agnostic and well suited to quantifying MIMT. Adopting this perspective, we show that the radial flow assumption is often harmless: to the extent that solute paths are reversible, the breakthrough curve is uninformative about velocity field heterogeneity. Our interpretation method determines a mapping function (i.e., subordinator) from travel time in the absence of MIMT to travel time in its presence. A mathematical theory allowing this function to be directly “plugged into” an existing Laplace-domain transport model to incorporate MIMT is presented and demonstrated. Algorithms implementing the calibration are presented and applied to interpretation of data from a push-pull test performed in a heterogeneous environment. A successful four-parameter fit is obtained, of comparable fidelity to one obtained using a million-node 3-D numerical model. In conclusion, we demonstrate analytically and numerically how push-pull tests quantifying MIMT are sensitive to remobilization, but not immobilization, kinetics.« less

  3. Push-out tests and evaluation of FRP perfobond rib shear connectors performance

    NASA Astrophysics Data System (ADS)

    Kolpasky, Ludvik; Ryjacek, Pavel

    2017-09-01

    The behavioural characteristics of FRP (fibre-reinforced polymer) perfobond rib shear connector was examined through push-out tests in order to verify the applicability for pedestrian bridge structure. The aim of this study is to determine interaction between high performance concrete slab and handmade FRP plate which represent web of the composite beam. Combination of these modern materials leads to structural system with both great load bearing capacity and also sufficient flexural stiffness of the composite element. Openings cut into the GFRP plate at a variable spacing allow GFRP reinforcement bars to be inserted to act as shear studs. Hand lay-up process can increase suitable properties of FRP for connection by perfobond rib shear connectors. In this study, three push-out tests on fiber-reinforced polymer were performed to investigate their shear behaviour. The results of the push-out tests on FRP perfobond rib shear connector indicates great promise for application in full scale structures.

  4. Modeling the impact of pedestrian behavior diversity on traffic dynamics at a crosswalk with push button

    NASA Astrophysics Data System (ADS)

    Xie, Dong-Fan; Zhao, Xiao-Mei; Li, Xin-Gang; Zhu, Tai-Lang

    2016-01-01

    Crosswalk with push button is prevalent in lots of cities for the purpose of promoting the efficiency of the crosswalk, and thus the delays of both vehicles and pedestrians can be reduced. This strategy has been confirmed to be effective in several developed countries. However, it is a pity that application of push button is aborted in some cities in China. In this work, diverse behaviors of vehicles and pedestrians are analyzed and discussed. Then, a microscopic model is developed by incorporating the interaction between vehicles and pedestrians. Numerical simulations are performed to reveal the characteristics of traffic flow and the efficiency of the signal control strategy. Also, the impacts of risker proportion and button reaction time, as well as the impacts of various behaviors as mass behavior, the patience of pedestrian and push button habit are investigated. It is expected that the results will be helpful to the strategy design of a signalized crosswalk in such developing countries as China.

  5. Micro/nano-mechanical test system employing tensile test holder with push-to-pull transformer

    DOEpatents

    Oh, Yunje; Cyrankowski, Edward; Shan, Zhiwei; Syed Asif, Syed Amanula

    2014-07-29

    A micromachined or microelectromechanical system (MEMS) based push-to-pull mechanical transformer for tensile testing of micro-to-nanometer scale material samples including a first structure and a second structure. The second structure is coupled to the first structure by at least one flexible element that enables the second structure to be moveable relative to the first structure, wherein the second structure is disposed relative to the first structure so as to form a pulling gap between the first and second structures such that when an external pushing force is applied to and pushes the second structure in a tensile extension direction a width of the pulling gap increases so as to apply a tensile force to a test sample mounted across the pulling gap between a first sample mounting area on the first structure and a second sample mounting area on the second structure.

  6. Micro/nano-mechanical test system employing tensile test holder with push-to-pull transformer

    DOEpatents

    Oh, Yunje; Cyrankowski, Edward; Shan, Zhiwei; Asif, Syed Amanula Syed

    2013-05-07

    A micromachined or microelectromechanical system (MEMS) based push-to-pull mechanical transformer for tensile testing of micro-to-nanometer scale material samples including a first structure and a second structure. The second structure is coupled to the first structure by at least one flexible element that enables the second structure to be moveable relative to the first structure, wherein the second structure is disposed relative to the first structure so as to form a pulling gap between the first and second structures such that when an external pushing force is applied to and pushes the second structure in a tensile extension direction a width of the pulling gap increases so as to apply a tensile force to a test sample mounted across the pulling gap between a first sample mounting area on the first structure and a second sample mounting area on the second structure.

  7. Pushing out the limits of electrical stimulation. A case study in the aggressive use of an alternative to voluntary exercise.

    PubMed

    Crowe, Louis; Caulfield, Brian

    2011-10-11

    Recent advances in neuromuscular electrical stimulation (NMES) suggest that sophisticated techniques can exercise and train people aerobically. However, the limits of this exercise modality would be of interest to sportspeople, trainers and rehabilitation experts. Additionally, there are physical and other barriers which prevent many from undertaking aggressive voluntary exercise. Maximum voluntary and peak NMES efforts were assessed for 1) maximal heart rate and oxygen consumption, 2) excess postexercise oxygen consumption (EPOC), 3) lactate and 4) time-to-fatigue while exercising at 65% of predicted maximal heart rate (maximum voluntary versus peak NMES efforts). Heart rates: 195 bpm and 194 bpm; Oxygen consumption: 52 ml/kg/min and 39 ml/kg/min. EPOC: 110.5 kcal and 96.5 kcal; Lactate: 15.0 mmol/l and 15.3 mmol/l; Time-to-fatigue: 4 h and over 6 h. Sophisticated NMES compares well to voluntary exercise with potential applications for sportspeople and some who cannot exercise due to disease or injury.

  8. Pushing the limits of radiofrequency (RF) neuronal telemetry

    PubMed Central

    Yousefi, Tara; Diaz, Rodolfo E.

    2015-01-01

    In a previous report it was shown that the channel capacity of an in vivo communication link using microscopic antennas at radiofrequency is severely limited by the requirement not to damage the tissue surrounding the antennas. For dipole-like antennas the strong electric field dissipates too much power into body tissues. Loop-type antennas have a strong magnetic near field and so dissipate much less power into the surrounding tissues but they require such a large current that the antenna temperature is raised to the thermal damage threshold of the tissue. The only solution was increasing the antenna size into hundreds of microns, which makes reporting on an individual neuron impossible. However, recently demonstrated true magnetic antennas offer an alternative not covered in the previous report. The near field of these antennas is dominated by the magnetic field yet they don’t require large currents. Thus they combine the best characteristics of dipoles and loops. By calculating the coupling between identical magnetic antennas inside a model of the body medium we show an increase in the power transfer of up to 8 orders of magnitude higher than could be realized with the loops and dipoles, making the microscopic RF in-vivo transmitting antenna possible. PMID:26035824

  9. Protective helmet assembly

    NASA Technical Reports Server (NTRS)

    Dawn, Frederic S. (Inventor); Weiss, Fred R. (Inventor); Eck, John D. (Inventor)

    1992-01-01

    The invention is a protective helmet assembly with improved safety and impact resistance, high resistance to ignition and combustion, and reduced offgassing. The assembly comprises a hard rigid ballistic outer shell with one or more impact absorbing pads fitted to the interior surface. The pads are made of open cell flexible polyimide foam material, each of which is attached to the inner surface of the ballistic outer shell by cooperative VELCRO fastener strips of hook-and-loop material affixed respectively to the rigid outer shell and the impact absorbing pads. The helmet assembly with shell and pads is sized to fit relatively close over a wearer's head.

  10. DC source assemblies

    DOEpatents

    Campbell, Jeremy B; Newson, Steve

    2013-02-26

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  11. Push-out bond strength of MTA with antiwashout gel or resins.

    PubMed

    Formosa, L M; Mallia, B; Camilleri, J

    2014-05-01

    Assessment of the push-out bond strength of four MTA-based formulations for use as root-end filling materials. MTA Plus mixed with (i) water ('MTA-W'); (ii) a proprietary water-based antiwashout gel ('MTA-AW'); (iii) Superbond C&B chemically curing resin ('MTA-Chem'); and (iv) Heliobond light-curing resin ('MTA-Light') was tested. Root slices 3 mm thick human had a 1.5 mm diameter hole drilled centrally and were treated with 17% EDTA for 60s. Forty specimens divided into groups 1-4 were prepared and filled with MTA-W, MTA-AW, MTA-Chem and MTA-Light, respectively. Groups 3 and 4 were etched with 37% phosphoric acid for 60s, and bonding agent was applied to the dentine surface. Specimens were stored for 28 days in Hanks' Balanced Salt Solution at 37 °C. Push-out strength was tested with a punch and die (punch diameter 1.3 mm, die diameter 2.0 mm, punch speed 1 mm min(-1)). Stereomicroscopy was used to classify failure mode (adhesive, cohesive or mixed type). The resulting push-out strengths were 5.1 MPa (MTA-W), 4.3 MPa (MTA-AW), 4.7 MPa (MTA-Chem) and 11.0 MPa (MTA-Light). MTA-W had higher push-out strength than MTA-AW (P = 0.022). The same was noted for MTA-Light relative to the other materials (P < 0.05). All materials exhibited adequate push-out strengths compared with MTA-W. Failure was predominantly mixed, except for MTA-Chem (predominantly adhesive). All materials exhibited adequate push-out strength. Previous studies have shown the new formulations have additional advantages including increased washout resistance and faster setting time, making them promising for future dental applications. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  12. Prototype pushing robot for emplacing vitrified waste canisters into horizontal disposal drifts

    SciTech Connect

    Londe, L.; Seidler, W.K.; Bosgiraud, J.M.

    2007-07-01

    Within the French Underground Disposal concept, as described in ANDRA's (Agence Nationale pour la Gestion des Dechets Radioactifs) Dossier 2005, the Pushing Robot is an application envisaged for the emplacement (and the potential retrieval) of 'Vitrified waste packages', also called 'C type packages'. ANDRA has developed a Prototype Pushing Robot within the framework of the ESDRED Project (Engineering Studies and Demonstration of Repository Design) which is co-funded by the European Commission as part of the sixth EURATOM Research and Training Framework Programme (FP6) on nuclear energy (2002 - 2006). The Rationale of the Pushing Robot technology comes from various considerations,more » including the need for (1) a simple and robust system, capable of moving (and potentially retrieving) on up to 40 metres (m), a 2 tonne C type package (mounted on ceramic sliding runners) inside the carbon steel sleeve constituting the liner (and rock support) of a horizontal disposal cell, (2) small annular clearances between the package and the liner, (3) compactness of the device to be transferred from surface to underground, jointly with the package, inside a shielding cask, and (4) remote controlled operations for the sake of radioprotection. The initial design, based on gripping supports, has been replaced by a 'technical variant' based on inflatable toric jacks. It was then possible, using a test bench, to check that the Pushing Robot worked properly. Steps as high as 7 mm were successfully cleared by a dummy package pushed by the Prototype.. Based on the lessons learned by ANDRA's regarding the Prototype Pushing Robot, a new Scope of Work is being written for the Contract concerning an Industrial Scale Demonstrator. The Industrial Scale Demonstration should be completed by the end of the second Quarter of 2008. (authors)« less

  13. Investigation of the push-pull effects on β-functionalized benzoporphyrins bearing an ethynylphenyl bridge.

    PubMed

    Waruna Jinadasa, R G; Thomas, Michael B; Hu, Yi; D'Souza, Francis; Wang, Hong

    2017-05-24

    A series of β-pyrrole functionalized push-pull porphyrins with amine push groups linked via an ethynylphenyl spacer, and cyclic imide or carboxylic esters as pull groups have been newly synthesized and characterized. The β-pyrrole functionalized ethynylphenyl spacer extends the conjugation of the porphyrin π-system, as reflected by their red-shifted absorbance and fluorescence spectra. The computed structures revealed no steric hindrance between the porphyrin π-system and the β-substituents. The calculated HOMO and LUMO of compounds WJ2 and WJ3 display significant segregation, where the electron density in the HOMO and LUMO is mainly located at the donor component and the acceptor component, respectively. The orbital segregation is likely attributed to the introduction of the electron-donating amine group at the porphyrin periphery. Electrochemical studies revealed the expected lower HOMO-LUMO gap as a result of the facile oxidation and reduction of the push-pull porphyrins. As a consequence of the push-pull effects, a reduction in fluorescence intensity and lifetime was observed, especially for compound WJ3 having two electron-donating amino groups and a strongly electron-withdrawing cyclic imide group. Femtosecond transient absorption spectral studies revealed the successful formation of the singlet excited state in all of these push-pull porphyrins. Due to the occurrence of intramolecular charge transfer-type interactions, relaxation of the singlet excited state was found to be faster in compound WJ3 compared to other two derivatives in polar solvent but not in nonpolar solvent. Such charge transfer-type interactions from the triplet excited state were also observed in the case of compound WJ3 in benzonitrile. The present findings bring out the importance of push-pull effects in governing the ground and excited (singlet and triplet) state properties of free-base porphyrins.

  14. An Alternative to Assembly-Line Education: Undergraduate Teaching Assistants

    ERIC Educational Resources Information Center

    Wallace, Ruth A.

    1974-01-01

    The author describes a teaching innovation in which undergraduates were used to lead weekly discussion sections of lower division sociology courses. The selection process of teaching assistants, student reactions, and possible solutions to potential problems are presented. (Author/DE)

  15. Waste compatibility safety issues and final results for tank 241-T-110 push mode samples

    SciTech Connect

    Nuzum, J.L.

    1997-05-15

    This document is the final laboratory report for Tank 241-T-110. Push mode core segments were removed from risers 2 and 6 between January 29, 1997, and February 7, 1997. Segments were received and extruded at 222-S Laboratory. Analyses were performed in accordance with Tank 241-T-110 Push Mode Core Sampling and analysis Plan (TSAP) and Safety Screening Data Quality Objective (DQO). None of the subsamples submitted for total alpha activity (AT) or differential scanning calorimetry (DSC) analyses exceeded the notification limits stated in DQO.

  16. Powerful tubular core free dielectric electro activate polymer (DEAP) push actuator

    NASA Astrophysics Data System (ADS)

    Tryson, Michael; Kiil, Hans-Erik; Benslimane, Mohamed

    2009-03-01

    DEAP Actuator structures are being developed and optimized with focus on high volume automated manufacturing techniques and processes. New core-free and self-supporting structures are capable of providing PUSH forces without external mechanical tension mechanisms or film pre-strain. Fundamental actuator design and construction principles are presented. A simple quasi-static model governing behaviour is presented and actual results from this new class of push actuator devices are compared to modelled behaviour. These actuators have the capability of modest stroke and high actuation forces. Actuators can be easily scaled to fit the application based upon physical size and force-stroke relationship.

  17. Pushing the Boundaries of Suborbital Soft X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    McEntaffer, Randall

    optics are planned for every future large X-ray mission and flight-proving the design is extremely important. The gratings will be radially grooved and blazed to reduce grating aberrations and to focus the spectrum to one side of zero-order. Gratings of this type have been well developed by the IXO Off- Plane X-ray Grating Spectrometer concept study, but have not been flight proven. The spectrum will be focused onto high spatial resolution CCD detectors. OGRE will draw heavily from the heritage gained from OGRESS. OGRE will observe Capella. Due to its high flux and spectral line density, Capella is an ideal target for showcasing the resolution capabilities of our instrument. As an important calibration target, our improved resolution measurements will be extremely helpful for many future X-ray observations. OGRESS has already provided three thesis projects for past graduate students. The upgrades and flights proposed here will produce at least two more PhD theses. This program in hands-on training of young scientists in the techniques of instrumental X-ray astronomy has proven very successful over nearly three decades, leading to high rates of launch, publication, graduation, and flight qualification of instrumental PI's. It will also provide full experiment cycle experience - design, fabrication, tolerancing, assembly, flight-qualification, calibration, integration, launch, and data analysis - with reflection gratings, GEM and CCD detectors, and other technologies suitable for adaptation to NASA's major missions. The University of Iowa and University of Colorado programs in suborbital X-ray astronomy represent an exciting mix of compelling science, cutting- edge technology development, and training of young scientists.

  18. Self-assembled nanostructured metamaterials

    NASA Astrophysics Data System (ADS)

    Ponsinet, Virginie; Baron, Alexandre; Pouget, Emilie; Okazaki, Yutaka; Oda, Reiko; Barois, Philippe

    2017-07-01

    The concept of metamaterials emerged in the years 2000 with the achievement of artificial structures enabling nonconventional propagation of electromagnetic waves, such as negative phase velocity or negative refraction. The electromagnetic response of metamaterials is generally based on the presence of optically resonant elements —or meta-atoms— of sub-wavelength size and well-designed morphology so as to provide the desired electric and magnetic optical properties. Top-down technologies based on lithography techniques have been intensively used to fabricate a variety of efficient electric and magnetic resonators operating from microwave to visible light frequencies. However, the technological limits of the top-down approach are reached in visible light where a huge number of nanometre-sized elements is required. We show here that the bottom-up fabrication route based on the combination of nanochemistry and the self-assembly methods of colloidal physics provide an excellent alternative for the large-scale synthesis of complex meta-atoms, as well as for the fabrication of 2D and 3D samples exhibiting meta-properties in visible light. Contribution to the Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.

  19. Integrated thruster assembly program

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The program is reported which has provided technology for a long life, high performing, integrated ACPS thruster assembly suitable for use in 100 typical flights of a space shuttle vehicle over a ten year period. The four integrated thruster assemblies (ITA) fabricated consisted of: propellant injector; a capacitive discharge, air gap torch type igniter assembly; fast response igniter and main propellant valves; and a combined regen-dump film cooled chamber. These flightweight 6672 N (1500 lb) thruster assemblies employed GH2/GO2 as propellants at a chamber pressure of 207 N/sq cm (300 psia). Test data were obtained on thrusted performance, thermal and hydraulic characteristics, dynamic response in pulsing, and cycle life. One thruster was fired in excess of 42,000 times.

  20. Self-assembling prodrugs.

    PubMed

    Cheetham, Andrew G; Chakroun, Rami W; Ma, Wang; Cui, Honggang

    2017-10-30

    Covalent modification of therapeutic compounds is a clinically proven strategy to devise prodrugs with enhanced treatment efficacies. This prodrug strategy relies on the modified drugs that possess advantageous pharmacokinetic properties and administration routes over their parent drug. Self-assembling prodrugs represent an emerging class of therapeutic agents capable of spontaneously associating into well-defined supramolecular nanostructures in aqueous solutions. The self-assembly of prodrugs expands the functional space of conventional prodrug design, affording a possible pathway to more effective therapies as the assembled nanostructure possesses distinct physicochemical properties and interaction potentials that can be tailored to specific administration routes and disease treatment. In this review, we will discuss the various types of self-assembling prodrugs in development, providing an overview of the methods used to control their structure and function and, ultimately, our perspective on their current and future potential.

  1. Automated Assembly Center (AAC)

    NASA Astrophysics Data System (ADS)

    Stauffer, Robert J.

    1993-02-01

    The objectives of this project are as follows: to integrate advanced assembly and assembly support technology under a comprehensive architecture; to implement automated assembly technologies in the production of high-visibility DOD weapon systems; and to document the improved cost, quality, and lead time. This will enhance the production of DOD weapon systems by utilizing the latest commercially available technologies combined into a flexible system that will be able to readily incorporate new technologies as they emerge. Automated assembly encompasses the following areas: product data, process planning, information management policies and framework, three schema architecture, open systems communications, intelligent robots, flexible multi-ability end effectors, knowledge-based/expert systems, intelligent workstations, intelligent sensor systems, and PDES/PDDI data standards.

  2. Composite turbine bucket assembly

    SciTech Connect

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to bemore » attached to the turbine rotor or disk.« less

  3. Swipe transfer assembly

    DOEpatents

    Christiansen, Robert M.; Mills, William C.

    1992-01-01

    The swipe transfer assembly is a mechanical assembly which is used in conjunction with glove boxes and other sealed containments. It is used to pass small samples into or out of glove boxes without an open breach of the containment, and includes a rotational cylinder inside a fixed cylinder, the inside cylinder being rotatable through an arc of approximately 240.degree. relative to the outer cylinder. An offset of 120.degree. from end to end allows only one port to be opened at a time. The assembly is made of stainless steel or aluminum and clear acrylic plastic to enable visual observation. The assembly allows transfer of swipes and smears from radiological and other specially controlled environments.

  4. Magnetostrictive valve assembly

    NASA Technical Reports Server (NTRS)

    Richard, James A. (Inventor)

    2008-01-01

    A magnetostrictive valve assembly includes a housing that defines a passage with a seat being formed therein. A magnetically-biased and axially-compressed magnetostrictive assembly slidingly fitted in the passage is configured as a hollow and open-ended conduit adapted to support a flow of a fluid therethrough. Current-carrying coil(s) disposed about the passage in the region of the magnetostrictive assembly generate a magnetic field in the passage when current flows through the coil(s). A hollow valve body with side ports is coupled on one end thereof to an axial end of the magnetostrictive assembly. The other end of the valve body is designed to seal with the seat formed in the housing's passage when brought into contact therewith.

  5. Assembly Line of Stars

    NASA Image and Video Library

    2010-05-06

    This image from NASA Herschel, in the constellation of Vulpecula, shows an entire assembly line of newborn stars. The diffuse glow reveals the widespread cold reservoir of raw material that our Milky Way galaxy has in stock for building stars.

  6. The proteasome assembly line

    PubMed Central

    Madura, Kiran

    2013-01-01

    The assembly of the proteasome — the cellular machine that eliminates unwanted proteins — is a carefully choreographed affair, involving a complex sequence of steps overseen by dedicated protein chaperones. PMID:19516331

  7. Core assembly storage structure

    DOEpatents

    Jones, Jr., Charles E.; Brunings, Jay E.

    1988-01-01

    A structure for the storage of core assemblies from a liquid metal-cooled nuclear reactor. The structure comprises an enclosed housing having a substantially flat horizontal top plate, a bottom plate and substantially vertical wall members extending therebetween. A plurality of thimble members extend downwardly through the top plate. Each thimble member is closed at its bottom end and has an open end adjacent said top plate. Each thimble member has a length and diameter greater than that of the core assembly to be stored therein. The housing is provided with an inlet duct for the admission of cooling air and an exhaust duct for the discharge of air therefrom, such that when hot core assemblies are placed in the thimbles, the heat generated will by convection cause air to flow from the inlet duct around the thimbles and out the exhaust duct maintaining the core assemblies at a safe temperature without the necessity of auxiliary powered cooling equipment.

  8. Lightweight, self-ballasting photovoltaic roofing assembly

    DOEpatents

    Dinwoodie, Thomas L.

    2006-02-28

    A photovoltaic roofing assembly comprises a roofing membrane (102), a plurality of photovoltaic modules (104, 106, 108) disposed as a layer on top of the roofing membrane (102), and a plurality of pre-formed spacers, pedestals or supports (112, 114, 116, 118, 120, 122) which are respectively disposed below the plurality of photovoltaic modules (104, 106, 108) and integral therewith, or fixed thereto. Spacers (112, 114, 116, 118, 120, 122) are disposed on top of roofing membrane (102). Membrane (102) is supported on conventional roof framing, and attached thereto by conventional methods. In an alternative embodiment, the roofing assembly may have insulation block (322) below the spacers (314, 314', 315, 315'). The geometry of the pre-formed spacers (112, 114, 116, 118, 120, 122, 314, 314', 315, 315') is such that wind tunnel testing has shown its maximum effectiveness in reducing net forces of wind uplift on the overall assembly. Such construction results in a simple, lightweight, self-ballasting, readily assembled roofing assembly which resists the forces of wind uplift using no roofing penetrations.

  9. Lightweight, self-ballasting photovoltaic roofing assembly

    DOEpatents

    Dinwoodie, T.L.

    1998-05-05

    A photovoltaic roofing assembly comprises a roofing membrane (102), a plurality of photovoltaic modules (104, 106, 108) disposed as a layer on top of the roofing membrane (102), and a plurality of pre-formed spacers, pedestals or supports (112, 114, 116, 118, 120, 122) which are respectively disposed below the plurality of photovoltaic modules (104, 106, 108) and integral therewith, or fixed thereto. Spacers (112, 114, 116, 118, 120, 122) are disposed on top of roofing membrane (102). Membrane (102) is supported on conventional roof framing, and attached thereto by conventional methods. In an alternative embodiment, the roofing assembly may have insulation block (322) below the spacers (314, 314', 315, 315'). The geometry of the preformed spacers (112, 114, 116, 118, 120, 122, 314, 314', 315, 315') is such that wind tunnel testing has shown its maximum effectiveness in reducing net forces of wind uplift on the overall assembly. Such construction results in a simple, lightweight, self-ballasting, readily assembled roofing assembly which resists the forces of wind uplift using no roofing penetrations.

  10. Lightweight, self-ballasting photovoltaic roofing assembly

    DOEpatents

    Dinwoodie, Thomas L.

    1998-01-01

    A photovoltaic roofing assembly comprises a roofing membrane (102), a plurality of photovoltaic modules (104, 106, 108) disposed as a layer on top of the roofing membrane (102), and a plurality of pre-formed spacers, pedestals or supports (112, 114, 116, 118, 120, 122) which are respectively disposed below the plurality of photovoltaic modules (104, 106, 108) and integral therewith, or fixed thereto. Spacers (112, 114, 116, 118, 120, 122) are disposed on top of roofing membrane (102). Membrane (102) is supported on conventional roof framing, and attached thereto by conventional methods. In an alternative embodiment, the roofing assembly may have insulation block (322) below the spacers (314, 314', 315, 315'). The geometry of the preformed spacers (112, 114, 116, 118, 120, 122, 314, 314', 315, 315') is such that wind tunnel testing has shown its maximum effectiveness in reducing net forces of wind uplift on the overall assembly. Such construction results in a simple, lightweight, self-ballasting, readily assembled roofing assembly which resists the forces of wind uplift using no roofing penetrations.

  11. Recuperator assembly and procedures

    DOEpatents

    Kang, Yungmo; McKeirnan, Jr., Robert D.

    2008-08-26

    A construction of recuperator core segments is provided which insures proper assembly of the components of the recuperator core segment, and of a plurality of recuperator core segments. Each recuperator core segment must be constructed so as to prevent nesting of fin folds of the adjacent heat exchanger foils of the recuperator core segment. A plurality of recuperator core segments must be assembled together so as to prevent nesting of adjacent fin folds of adjacent recuperator core segments.

  12. Recuperator assembly and procedures

    DOEpatents

    Kang, Yungmo; McKeirnan, Jr., Robert D.

    2006-06-27

    A construction of recuperator core segments is provided which insures proper assembly of the components of the recuperator core segment, and of a plurality of recuperator core segments. Each recuperator core segment must be constructed so as to prevent nesting of fin folds of the adjacent heat exchanger foils of the recuperator core segment. A plurality of recuperator core segments must be assembled together so as to prevent nesting of adjacent fin folds of adjacent recuperator core segments.

  13. VIRUS instrument collimator assembly

    NASA Astrophysics Data System (ADS)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  14. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  15. Vehicle Assembly Building (VAB)

    NASA Image and Video Library

    2017-09-27

    NASA's Vehicle Assembly Building at Kennedy Space Center in Florida was used to assemble and house American-crewed launch vehicles from 1968 to 2011. AT 3,684,883 cubic meters, it is one of the largest buildings in the world by volume. Inside the facility, High Bay 3 is being upgraded and modified to support processing of the agency's Space Launch System rocket and Orion spacecraft.

  16. Alternative Pathways to Apprenticeships. Good Practice Guide

    ERIC Educational Resources Information Center

    National Centre for Vocational Education Research (NCVER), 2015

    2015-01-01

    Apprenticeships are changing. The increasing proportions of people entering apprenticeships at various levels of ability and backgrounds are stimulating demand for alternative pathways to completions. This good practice guide assembles the key findings for education practitioners and workplace supervisors from three related research reports on…

  17. Hugs and Behaviour Points: Alternative Education and the Regulation of "Excluded" Youth

    ERIC Educational Resources Information Center

    Thomson, Pat; Pennacchia, Jodie

    2016-01-01

    In England, alternative education (AE) is offered to young people formally excluded from school, close to formal exclusion or who have been informally pushed to the educational edges of their local school. Their behaviour is seen as needing to change. In this paper, we examine the behavioural regimes at work in 11 AE programmes. Contrary to…

  18. The Effect of Prosthetic Foot Push-off on Mechanical Loading Associated with Knee Osteoarthritis in Lower Extremity Amputees

    PubMed Central

    Morgenroth, David C.; Segal, Ava D.; Zelik, Karl E.; Czerniecki, Joseph M.; Klute, Glenn K.; Adamczyk, Peter G.; Orendurff, Michael S.; Hahn, Michael E.; Collins, Steven H.; Kuo, Art D.

    2011-01-01

    Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope = −0.72 +/− 0.22; p=0.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope = −0.34 +/− 0.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population. PMID:21803584

  19. Needlescopic sleeve gastrectomy: pushing the boundaries of the standard technique.

    PubMed

    Loureiro, Marcelo; Sultan, Abdulah; Alhaddad, Mohannad; Mostafa, Hatem; Nocca, David; Nedelcu, Marius; Buhaimed, Walled

    2017-10-01

    performed with fewer trocars, using for example special designed internal retractors or even the posterior part of the dissected stomach to replace the liver retractor and its trocar [5, 6]. Single port is another well-known possibility [7, 8], but mini-laparoscopy or needlescopic SG is still not well explored in our opinion. We believe that this technical alternative proposed in this video keeps the standards of care and safety of conventional LSG. There is no change in the position of the surgeon, not even the trocars. Specially designed needlescopic instruments show enough strength to be used in bariatrics and allow the surgeon to perform all the routine maneuvers from dissection to suturing. LSG can be done by mini-laparoscopy with a short adaptation period, previewing a short learning curve with no increase in the complications rate. NSG is feasible in selected patients and with few modifications in the standard technique. There might be a benefit in terms of pain. Further studies with large series are necessary to observe these potential benefits.

  20. Dynamic and electromyographical analysis in variants of push-up exercise.

    PubMed

    Gouvali, Marina K; Boudolos, Konstantinos

    2005-02-01

    The purpose of the study was to record dynamic and muscular modifications during push-up exercise variants (EV). Eight healthy men performed 6 EV of push-ups: normal, abducted, adducted, posterior, anterior, and on knees. Ground-reaction forces were recorded with a force plate while surface muscular activity with electrodes on triceps and pectoralis major. Significant differences (p < 0.05) existed for most vertical force variables but not for anteroposterior force and time variables. The initial load relative to body weight was 66.4% at the normal position, while only 52.9% at the on-knees EV. Muscle activity was less during the on-knees EV for both muscles. At the posterior EV, pectoralis major was activated higher than normal; however, triceps were activated lower than normal. Dynamic behavior and muscle activity were significantly altered between push-up EV. Instructions for push-up exercises should be followed carefully because dynamic and muscular challenge is altered when hands are differently positioned.

  1. Voices from the "Working Lives" Project: The Push-Pull of Work and Care

    ERIC Educational Resources Information Center

    Fehring, Heather; Herring, Katherine

    2012-01-01

    A recent policy direction in many OECD countries has been to increase workforce participation for women of childbearing age; a policy direction which seemingly runs counter to a need for improved work-life balance for women themselves. This article explores the impact of this somewhat contradictory "push-pull" of policy by examining some…

  2. MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

    EPA Science Inventory

    U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a
    Geopr...

  3. From Source to Sink: Mechanistic Reasoning Using the Electron-Pushing Formalism

    ERIC Educational Resources Information Center

    Bhattacharyya, Gautam

    2013-01-01

    Since the introduction of Morrison and Boyd's textbook in organic chemistry over 50 years ago, reaction mechanisms and mechanistic reasoning using the electron-pushing formalism (EPF) have become a mainstay of organic chemistry courses. In recent years there have even been several papers in this Journal and others detailing research on how…

  4. "You Hafta Push": Using Sapphire's Novel to Teach Introduction to American Government

    ERIC Educational Resources Information Center

    Pappas, Christine

    2007-01-01

    Using fiction in the classroom can dramatize public policy issues and political science concepts, therefore, making them more real and relevant to students. Sapphire's 1996 novel "Push" puts a face on welfare, rape, incest, child abuse, educational inequalities, homophobia, and AIDS. I also use this novel to discuss the public policy process,…

  5. Demonstration/Validation of Long-Term Monitoring Using Wells Installed by Direct-Push Technologies

    DTIC Science & Technology

    2008-04-01

    Oxygen DoD Department of Defense DOE Department of Energy DP Direct-Push EPA Environmental Protection Agency ERDC Army Corps Engineering... Protection Agency UST Underground Storage Tank VOA Volatile Organic Analyte VOC Volatile Organic Compound WDS Well Design Specification ix...12 Figure 2-4. Installation of a Pre-Packed, Protected Screen DP

  6. Mechanics of the Fiber-Matrix Interphase Push-Out Test

    DTIC Science & Technology

    2005-09-01

    available finite element code ABAQUS (Hibbitt, Karlsson, and Sorenson, Inc.) [14] was used for FEM analysis. The fiber push-out model was modeled with a...Dynamic Interphase Loading Apparatus”, J. Composites: Part A, 33, 1345-1348, 2002. [14] ABAQUS User Manual, Version 5.8, Hibbitt, Karlsson & Sorensen, Inc

  7. Evaluation of Push-In/Integrated Therapy in a Collaborative Preschool for Children with Special Needs

    ERIC Educational Resources Information Center

    Hernandez, Stephen J.

    2012-01-01

    With support found in the literature for the utilization of push-in, or integrated therapy when providing speech language pathology, the use of a set of criteria for determining how therapy would be provided was evaluated in a preschool for children with special needs. Using a 5-item Likert scale, teachers and speech pathologists were surveyed…

  8. A relationship between Raman and infrared spectra: the case of push pull molecules

    NASA Astrophysics Data System (ADS)

    Del Zoppo, M.; Tommasini, M.; Castiglioni, C.; Zerbi, G.

    1998-04-01

    Vibrational spectra of push-pull polyenes show a peculiar feature namely, in infrared and Raman spectra strong, coincident bands appear, arising from vibrations localised on the polyene bridge. A simple model, based on the introduction of an effective internal field due to the charge transfer between end groups allows the infrared and Raman intensities of these bands to be related.

  9. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or pushing...

  10. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or pushing...

  11. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Radio communication used in shoving, backing or... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.49 Radio communication used in shoving, backing or pushing...

  12. Push-out bond strength of different tricalcium silicate-based filling materials to root dentin.

    PubMed

    Stefaneli Marques, Jorge Henrique; Silva-Sousa, Yara Teresinha Corrêa; Rached-Júnior, Fuad Jacob Abi; Macedo, Luciana Martins Domingues de; Mazzi-Chaves, Jardel Francisco; Camilleri, Josette; Sousa-Neto, Manoel Damião

    2018-03-08

    The aim of this study was to evaluate the bond strength of different triccalcium silicate cements to retrograde cavity using a push out test. Thirty maxillary central incisors were shaped using #80 hand files and sectioned transversally. Root slices were obtained from the apical 4 mm after eliminating the apical extremity. The specimens were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. The samples were divided into three groups according to the root-end filling material (n = 10): MTA Angelus, ProRoot MTA and Biodentine. A gutta-percha cone (#80) was tugged-back at the limit between the canal and the root-end cavity. The root-end cavity was filled and the gutta-percha cone was removed after complete setting of the materials. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and push out testing was performed at a crosshead speed of 1.0 mm/min. There was no statistically significant difference in resistance to push out by the materials tested (p > 0.01). MTA Angelus and ProRoot MTA showed predominantly mixed failure while Biodentine exhibited mixed and cohesive failures. The tricalcium silicate-based root-end filling materials showed similar bond strength retrograde cavity.

  13. When People Push Water Deep Under Ground, It Can Cause Repeating Ground Shakes

    NASA Astrophysics Data System (ADS)

    Brudzinski, M.; Skoumal, R.; Currie, B.

    2016-12-01

    We look for ground shakes that repeat many times using a fast computer. We can do this when people put out a box that senses ground waves and stores all of them in computer memory. When a ground shake happens, we take the wave form from the ground shake, and use the fast computer to look for any matching wave forms in all of the ground waves stored in memory. Repeating ground shakes can happen when people push water deep down into the ground, which makes it easier for rocks to slip past each other. Sometimes people really push water down deep to break tight rocks and get more stuff stored inside that we use for power. The left over water from breaking rocks is not clean so it often gets pushed down even deeper, far away from the water people drink. In 99 out of 100 cases, pushing the water deep down under ground does not cause ground shakes we can see, even with a computer. Even fewer cases can be felt by people. In the cases where the water causes ground shakes, very small repeating ground shakes often happen early on. We can use a fast computer to find these repeating ground shakes to help us know if larger ground shakes might happen.

  14. Push and pull: Exposure of young Taiwanese women to sexually explicit materials.

    PubMed

    Tseng, Ying-Hua; Esposito, Noreen; Kuo, Shih-Hsien; Chou, Fan-Hao; Cheng, Mei-Li

    2017-08-01

    This study was designed to understand young Taiwanese women's perception of sexually explicit materials (SEMs). Researchers conducted six focus group discussions with 38 young women between the ages of 18 and 22 in Taiwan in 2009-2010 and used content analysis to analyze the data based on the push-pull theory. The results showed that the exposure of young women to SEMs was a sexual exploration process from no sexual activity to future sexual activity. This process was affected by the interactions of three powers: push power, pull power, and personal factors. The push power included factors, such as parents and social values, which failed to satisfy their sexual curiosity and provide them with autonomy. The pull power included SEMs and peer influence, which increased sexual arousal stimuli and curiosity to try sexual activity. The most important personal factors were young women's growth, including sexual curiosity, cognition of SEMs, and gender equity in freedom to make sexual decisions. Understanding this push-pull process regarding SEM can help health-care providers with their own discourses in addressing sex and influence young women's participation in desired, protected, and enjoyable sex when sufficiently ready.

  15. Six Impossible Mechanisms before Breakfast: Arrow Pushing as an Instructional Device in Inorganic Chemistry

    ERIC Educational Resources Information Center

    Berg, Steffen; Ghosh, Abhik

    2013-01-01

    In a recent article by the authors, the suggestion was made that arrow pushing, a widely used tool in organic chemistry, could also be profitably employed in the teaching of introductory inorganic chemistry. A number of relatively simple reactions were used to illustrate this thesis, raising the question whether the same approach might rationalize…

  16. Study on dynamic imaging on TDI CCD optical remote sensor of push-broom technology

    NASA Astrophysics Data System (ADS)

    Gao, Ming-hui; Zhao, Gui-jun; Liu, Lei; Ren, Jian-yue

    2010-10-01

    A set special detecting system is proposed based on TDICCD push-broom technology applying in dynamic imaging detecting experiment of space optics remote sensor. In the system, push-broom movement of the satellite is simulated through using double supporting U structure precision rotary platform with remote sensor by angular speed 0.555°/s,within the range of +/-5° and control precision on steady speed achieves 0.3%; In the course of detecting , regard Nyquist frequency target as detecting aim ,in order to solve matching uncertainty between the CCD pixel and the vertical target strip image when the remote sensor does push-broom, make matching simplify, enhance the measurement result the accuracy. So the tolerance a/n arithmetic progression gap target strip is joined in each group of rectangular vertical group target strip. The remote sensor obtains in vertical, the level and 45° the direction 0 fields of view, +/-0.86 the field of view Nyquist frequency target strip image after detected, a group target strip which can precision matching to TDICCD pixel at least can be obtained through analysis and dealing with 0.86 field of view's target strip image. The experiment not only verifies the detecting system's feasibility but simultaneously verifies whether to have the high quality dynamic imaging quality when TDICCD push-broom technology is adopted on the remote sensor developed.

  17. Does External Funding Push Doctoral Supervisors to Be More Directive? A Large-Scale Danish Study

    ERIC Educational Resources Information Center

    Wichmann-Hansen, Gitte; Herrmann, Kim Jesper

    2017-01-01

    Around the world, changing funding policies have pushed for university departments to find increased external project-based funding. While this trend is widely acknowledged, mixed views exist about implications for faculty members' academic practices. Regarding doctoral education, researchers have raised concern that external funding will push…

  18. Making Sense of the Arrow-Pushing Formalism among Chemistry Majors Enrolled in Organic Chemistry

    ERIC Educational Resources Information Center

    Ferguson, Robert; Bodner, George M.

    2008-01-01

    This paper reports results of a qualitative study of sixteen students enrolled in a second year organic chemistry course for chemistry and chemical engineering majors. The focus of the study was student use of the arrow-pushing formalism that plays a central role in both the teaching and practice of organic chemistry. The goal of the study was to…

  19. Sunlight-switchable light shutter fabricated using liquid crystals doped with push-pull azobenzene.

    PubMed

    Oh, Seung-Won; Baek, Jong-Min; Yoon, Tae-Hoon

    2016-11-14

    We propose a sunlight-switchable light shutter using liquid crystal/polymer composite doped with push-pull azobenzene. The proposed light shutter is switchable between the translucent and transparent states by application of an electric field or by UV irradiation. Switching by UV irradiation is based on the change of the liquid crystal (LC) clearing point by the photo-isomerization effect of push-pull azobenzene. Under sunlight, the light shutter can be switched from the translucent to the transparent state by the nematic-isotropic phase transition of the LC domains triggered by trans-cis photo-isomerization of the push-pull azobenzene molecules. When the amount of sunlight is low because of cloud cover or when there is no sunlight at sunset, the light shutter rapidly relaxes from its transparent state back to its initial translucent state by the isotropic-nematic phase transition induced by cis-trans back-isomerization of the push-pull azobenzene molecules.

  20. Pushed or Pulled? Exploring the Factors Underpinning Graduate Start-Ups and Non-Start-Ups

    ERIC Educational Resources Information Center

    Nabi, G.; Walmsley, A.; Holden, R.

    2015-01-01

    The study explores the nature and mixture of push--pull factors in the journey from higher education into graduate entrepreneurship. Using longitudinal data from 15 graduates of a British university, it compares graduates who started their own business with graduates that did not. Importantly, both groups had initially indicated a strong desire to…

  1. The Quest for Instantaneous Perfection and the Demand for "Push-Button" Administration

    ERIC Educational Resources Information Center

    Batagiannis, Stella C.

    2009-01-01

    Educational leaders in the United States are faced with a society seeking instantaneous perfection, immediate and perfect solutions. In education, this leads to a demand for push-button administration and an abandonment of trust in educators' judgment. As exemplified by the No Child Left Behind Act (2002), the search for quick fixes results in…

  2. Even the Snow Is White: Displacement and Literary Ecology in Diane Glancy's "Pushing the Bear"

    ERIC Educational Resources Information Center

    Hada, Kenneth

    2009-01-01

    Diane Glancy's historical fiction, "Pushing the Bear", reconstructs one episode in the Cherokee Trails of Tears (there were actually several relocations to the west, for the Cherokee and the other eastern tribes of the same period). The Removal of eastern peoples from their ancestral lands westward to eventual resettlement in Oklahoma is…

  3. A Novel Dentin Push-out Bond Strength Model That Uses Micro-Computed Tomography.

    PubMed

    Brito-Júnior, Manoel; Leoni, Graziela Bianchi; Pereira, Rodrigo Dantas; Faria-e-Silva, André Luis; Gomes, Erica Alves; Silva-Sousa, Yara Teresinha; Sousa-Neto, Manoel Damião

    2015-12-01

    Current push-out experimental methods used in endodontic research should be improved. This study introduced a novel dentin push-out bond strength model that uses micro-computed tomography (μCT). Roots filled with gutta-percha cones and different resin-based sealers (n = 10) were sectioned transversely to obtain two 2-mm-thick slices per root third. The first slice was subjected to a push-out test by using a material testing stage fitted inside a μCT scanner. The apparatus was scanned before and after the test to evaluate areas of filling material ruptures. The images provided by μCT were also used to generate models for a 3-dimensional finite element analysis. Confocal laser scanning microscopy was used to assess failure modes after the test and to measure interfacial gaps in slices not subjected to push-out. Bond-strength and gap data were statistically analyzed (P < .05). Proper coefficients of variation (average less than 30%) were observed for all the experimental conditions. The finite element analysis helped explain the results of bond strength and root-filling ruptures. A significant, moderate, indirect correlation was observed between the bond strength and gaps. The micromechanical model with the μCT images resulted in a consistent root-filling bond strength evaluation. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. An Information Push-Delivery System Design for Personal Information Service on the Internet.

    ERIC Educational Resources Information Center

    Chen, Chen-Tung; Tai, Wei-Shen

    2003-01-01

    Discussion of information overload from the Internet focuses on an information push-delivery system, which applies fuzzy information retrieval and fuzzy similarity measurement to avoid the information overload problem. Describes an empirical investigation conducted with students at Da-Yeh University (Taiwan) that investigated satisfaction with a…

  5. Itinerant Deaf Educator and General Educator Perceptions of the D/HH Push-in Model

    ERIC Educational Resources Information Center

    Rabinsky, Rebecca J.

    2013-01-01

    A qualitative case study using the deaf and hard of hearing (D/HH) push-in model was conducted on the perceptions of 3 itinerant deaf educators and 3 general educators working in 1 school district. Participants worked in pairs of 1 deaf educator and 1 general educator at 3 elementary schools. Open-ended research questions guided the study, which…

  6. Business and Education as Push-Pull Processes: An Alliance of Philosophy and Practice.

    ERIC Educational Resources Information Center

    Arif, Mohammed; Smiley, Frederick M.; Kulonda, Dennis J.

    2005-01-01

    In the 1960s, the U.S. business community utilized the term "push/pull" to indicate whether or not industry should use the "one-size-fits all" or whether it should listen to consumers' needs and feedback as a system of producing and marketing products. As well, U.S. public education has become much more accountability-laden…

  7. Interface Stability Influences Torso Muscle Recruitment and Spinal Load During Pushing Tasks

    PubMed Central

    LEE, P. J.; GRANATA, K. P.

    2006-01-01

    Handle or interface design can influence torso muscle recruitment and spinal load during pushing tasks. The objective of the study was to provide insight into the role of interface stability with regard to torso muscle recruitment and biomechanical loads on the spine. Fourteen subjects generated voluntary isometric trunk flexion force against a rigid interface and similar flexion exertions against an unstable interface, which simulated handle design in a cart pushing task. Normalized electromyographic (EMG) activity in the rectus abdominus, external oblique and internal oblique muscles increased with exertion effort. When using the unstable interface, EMG activity in the internal and external oblique muscle groups was greater than when using the rigid interface. Results agreed with trends from a biomechanical model implemented to predict the muscle activation necessary to generate isometric pushing forces and maintain spinal stability when using the two different interface designs. The co-contraction contributed to increased spinal load when using the unstable interface. It was concluded that handle or interface design and stability may influence spinal load and associated risk of musculoskeletal injury during manual materials tasks that involve pushing exertions. PMID:16540437

  8. Targeted Drug Delivery in the Suprachoroidal Space by Swollen Hydrogel Pushing

    PubMed Central

    Jung, Jae Hwan; Desit, Patcharin; Prausnitz, Mark R.

    2018-01-01

    Purpose The purpose is to target model drug particles to the posterior region of the suprachoroidal space (SCS) of the eye controlled via pushing by hydrogel swelling. Methods A particle formulation containing 1% hyaluronic acid (HA) with fluorescent polymer particles and a hydrogel formulation containing 4% HA were introduced in a single syringe as two layers without mixing, and injected sequentially into the SCS of the rabbit eye ex vivo and in vivo using a microneedle. Distribution of particles in the eye was determined by microscopy. Results During injection, the particle formulation was pushed toward the middle of the SCS by the viscous hydrogel formulation, but less than 12% of particles reached the posterior SCS. After injection, the particle formulation was pushed further toward the macula and optic nerve in the posterior SCS by hydrogel swelling and spreading. Heating the eye to 37°C, or injecting in vivo decreased viscosity and mechanical strength of the hydrogel, thereby allowing it to swell and flow further in the SCS. A high salt concentration (9% NaCl) in the hydrogel formulation further increased hydrogel swelling due to osmotic flow into the hydrogel. In this way, up to 76% of particles were delivered to the posterior SCS from an injection made near the limbus. Conclusions This study shows that model drug particles can be targeted to the posterior SCS by HA hydrogel swelling and pushing without particle functionalization or administering external driving forces. PMID:29677369

  9. DETECTION OF A GROUND-WATER/SURFACE-WATER INTERFACE WITH DIRECT-PUSH EQUIPMENT

    EPA Science Inventory

    A ground-water/surface-water interface (GSI) was documented at the Thermo Chem CERCLA Site in Muskegon, MI via direct-push (DP) sampling. At that time, contaminated ground water flowed from the upland area of the site into the Black Creek floodplain. DP rods equipped with a 1.5...

  10. Assemblies of Conformal Tanks

    NASA Technical Reports Server (NTRS)

    DeLay, Tom

    2009-01-01

    Assemblies of tanks having shapes that conform to each other and/or conform to other proximate objects have been investigated for use in storing fuels and oxidizers in small available spaces in upper stages of spacecraft. Such assemblies might also prove useful in aircraft, automobiles, boats, and other terrestrial vehicles in which space available for tanks is limited. The basic concept of using conformal tanks to maximize the utilization of limited space is not new in itself: for example, conformal tanks are used in some automobiles to store windshield -washer liquid and coolant that overflows from radiators. The novelty of the present development lies in the concept of an assembly of smaller conformal tanks, as distinguished from a single larger conformal tank. In an assembly of smaller tanks, it would be possible to store different liquids in different tanks. Even if the same liquid were stored in all the tanks, the assembly would offer an advantage by reducing the mechanical disturbance caused by sloshing of fuel in a single larger tank: indeed, the requirement to reduce sloshing is critical in some applications. The figure shows a prototype assembly of conformal tanks. Each tank was fabricated by (1) copper plating a wax tank mandrel to form a liner and (2) wrapping and curing layers of graphite/epoxy composite to form a shell supporting the liner. In this case, the conformal tank surfaces are flat ones where they come in contact with the adjacent tanks. A band of fibers around the outside binds the tanks together tightly in the assembly, which has a quasi-toroidal shape. For proper functioning, it would be necessary to maintain equal pressure in all the tanks.

  11. Delineating Hydraulic Conductivity with Direct Push Electrical Conductivity and High-Resolution Slug Testing

    NASA Astrophysics Data System (ADS)

    Healey, J. M.; McElwee, C. D.; Engard, B.

    2004-12-01

    Direct push technology continues to make advances in efficiently measuring water related parameters in unconsolidated sediments. A direct push subsurface profiling technique used during field investigations measures the electrical conductivity (EC) of sediments and fluid surrounding the EC probe. The EC geophysical method is typically used for gross lithologic definition. When numerous direct push EC profiles are completed, a general impression of vertical and lateral variation of subsurface lithology can be inferred. Unfortunately, these EC profiles do not directly measure the hydraulic conductivity, even though the profiles may indicate the presence of fine-grained material such as silt and clay, which are known to affect the hydraulic conductivity. The direct push EC vertical profiles can be obtained quickly and efficiently over an extended area. These EC profiles can be examined for regions that display a subsurface EC response with a potentially interesting behavior of the hydraulic conductivity. At selected locations, 5cm (2 inch) PVC monitoring wells with appropriate screen lengths can be installed by direct push techniques. We have developed equipment and techniques for performing high-resolution slug tests efficiently in 5cm (2 inch) wells. Correlation of the EC response and the high-resolution slug test results can aid in developing a 3-D picture of the hydraulic conductivity distribution at a given site. In this paper, we present the results of such a correlation for a well located near the Geohydrologic Experiment and Monitoring Site (GEMS) at the University of Kansas in the Kansas River valley. During the installation of this well with direct push equipment, it was discovered that the EC log indicated a prominent but relatively thin silt-clay layer at depth, which is somewhat unusual for this area. We routinely perform high-resolution slug testing efficiently over intervals as small as 7.5cm (3 inches) to 15cm (6 inches); therefore, we decided to see

  12. Self-assembled tunable networks of sticky colloidal particles

    SciTech Connect

    Demortiere, Arnaud; Snezhko, Oleksiy Alexey; Sapozhnikov, Maksim

    2017-07-18

    Self-assembled tunable networks of microscopic polymer fibers ranging from wavy colloidal "fur" to highly interconnected networks are created from polymer systems and an applied electric field. The networks emerge via dynamic self-assembly in an alternating (ac) electric field from a non-aqueous suspension of "sticky" polymeric colloidal particles with a controlled degree of polymerization. The resulting architectures are tuned by the frequency and amplitude of the electric field and surface properties of the particles.

  13. Alternative Splice in Alternative Lice

    PubMed Central

    Tovar-Corona, Jaime M.; Castillo-Morales, Atahualpa; Chen, Lu; Olds, Brett P.; Clark, John M.; Reynolds, Stuart E.; Pittendrigh, Barry R.; Feil, Edward J.; Urrutia, Araxi O.

    2015-01-01

    Genomic and transcriptomics analyses have revealed human head and body lice to be almost genetically identical; although con-specific, they nevertheless occupy distinct ecological niches and have differing feeding patterns. Most importantly, while head lice are not known to be vector competent, body lice can transmit three serious bacterial diseases; epidemictyphus, trench fever, and relapsing fever. In order to gain insights into the molecular bases for these differences, we analyzed alternative splicing (AS) using next-generation sequencing data for one strain of head lice and one strain of body lice. We identified a total of 3,598 AS events which were head or body lice specific. Exon skipping AS events were overrepresented among both head and body lice, whereas intron retention events were underrepresented in both. However, both the enrichment of exon skipping and the underrepresentation of intron retention are significantly stronger in body lice compared with head lice. Genes containing body louse-specific AS events were found to be significantly enriched for functions associated with development of the nervous system, salivary gland, trachea, and ovarian follicle cells, as well as regulation of transcription. In contrast, no functional categories were overrepresented among genes with head louse-specific AS events. Together, our results constitute the first evidence for transcript pool differences in head and body lice, providing insights into molecular adaptations that enabled human lice to adapt to clothing, and representing a powerful illustration of the pivotal role AS can play in functional adaptation. PMID:26169943

  14. Fast Regulation of Vertical Squat Jump during Push-Off in Skilled Jumpers.

    PubMed

    Fargier, Patrick; Massarelli, Raphael; Rabahi, Tahar; Gemignani, Angelo; Fargier, Emile

    2016-01-01

    The height of a maximum Vertical Squat Jump (VSJ) reflects the useful power produced by a jumper during the push-off phase. In turn this partly depends on the coordination of the jumper's segmental rotations at each instant. The physical system constituted by the jumper has been shown to be very sensitive to perturbations and furthermore the movement is realized in a very short time (ca. 300 ms), compared to the timing of known feedback loops. However, the dynamics of the segmental coordination and its efficiency in relation to energetics at each instant of the push-off phase still remained to be clarified. Their study was the main purpose of the present research. Eight young adult volunteers (males) performed maximal VSJ. They were skilled in jumping according to their sport activities (track and field or volleyball). A video analysis on the kinematics of the jump determined the influence of the jumpers' segments rotation on the vertical velocity and acceleration of the body mass center (MC). The efficiency in the production of useful power at the jumpers' MC level, by the rotation of the segments, was measured in consequence. The results showed a great variability in the segmental movements of the eight jumpers, but homogeneity in the overall evolution of these movements with three consecutive types of coordination in the second part of the push-off (lasting roughly 0.16 s). Further analyses gave insights on the regulation of the push-off, suggesting that very fast regulation(s) of the VSJ may be supported by: (a) the adaptation of the motor cerebral programming to the jumper's physical characteristics; (b) the control of the initial posture; and (c) the jumper's perception of the position of his MC relative to the ground reaction force, during push-off, to reduce energetic losses.

  15. Micro push-out bond strengths of 2 fiber post types luted using different adhesive strategies.

    PubMed

    Erdemir, Ugur; Mumcu, Emre; Topcu, Fulya Toksoy; Yildiz, Esra; Yamanel, Kivanc; Akyol, Mesut

    2010-10-01

    The objective of this study was to evaluate the push-out bond strengths of carbon and glass fiber posts adhesively luted with Panavia F 2.0 and RelyX Unicem luting cements, as well as a modified application procedure using RelyX Unicem cement in combination with a single-bottle total-etch adhesive in 3 segments of teeth. Sixty single-rooted human maxillary central incisors and canines were sectioned below the cementoenamel junction, and the roots were endodontically treated. The roots were divided into 2 fiber-post groups, and then divided into 3 subgroups of 10 specimens each to test different luting strategies. Bonded specimens were cut (1-mm-thick sections) and push-out tests were performed (crosshead-speed, 0.5 mm/min). Failure modes were evaluated using a stereomicroscope at original magnification ×40. Micro push-out bond strengths were significantly affected by the type of luting agent and the type of post (P < .05). In all root sections, the push-out bond strength values of glass fiber posts were significantly higher than that of carbon fiber posts (P < .05). Moreover, the highest push-out bond strengths were measured for Panavia F 2.0 and RelyX Unicem cements. These values were significantly higher than that of modified application procedure in the medium section for both glass- and carbon-fiber posts, and in the apical root sections only for glass-fiber post (P < .05). In each region, the modified application procedure showed the lowest bond strength values. Adhesive failure between dentin and cement was the most frequent type of failure. In all root segments, the glass fiber post provided significantly increased post retention compared with the carbon fiber post, regardless of the luting strategy used. Copyright © 2010 Mosby, Inc. All rights reserved.

  16. Scapular Kinematics and Shoulder Elevation in a Traditional Push-Up

    PubMed Central

    Suprak, David N.; Bohannon, Jennifer; Morales, Gabriel; Stroschein, Joseph; San Juan, Jun G.

    2013-01-01

    Context: Proper scapulothoracic motion is critical for the health and function of the shoulder and represents a principal focus in the rehabilitation setting. Variants of the traditional push-up are used frequently to help restore proper scapular kinematics. To date, substantial research has focused on muscle activation levels of rotator cuff and scapular-stabilizing musculature, whereas a dearth of literature exists regarding scapular kinematics during push-up variants. Objective: To examine the effect of shoulder position on scapular kinematics across the range of motion (ROM) of a traditional push-up. Design: Cross-sectional study. Setting: University laboratory. Patients or Other Participants: Sixteen healthy participants without a history of upper extremity or spine injury requiring rehabilitation or surgery. Intervention(s): Participants performed a traditional push-up while kinematic measurements were acquired from multiple upper extremity segments. The 3 shoulder position conditions were (1) self-selected position, (2) shoulder adducted upon ascent (at side), and (3) shoulder elevated to approximately 90°. Main Outcome Measure(s): Scapular posterior tilt, upward rotation, and external rotation were examined across elbow-extension ROM and compared across conditions. Results: Posterior tilt was greater in the self-selected and at-side conditions than in the elevated condition and increased linearly with elbow extension. External rotation was greater in the self-selected and at-side conditions compared with that in the elevated condition. In the at-side condition, upward rotation began lower than in the other conditions at the start of the concentric phase but increased above the others soon after the elbow started to extend. Conclusions: Performing a traditional push-up with the shoulders elevated may place the scapula in a position of impingement. Clinicians should be cognizant of shoulder elevation when prescribing and monitoring exercise progression. The

  17. Impulsive ankle push-off powers leg swing in human walking.

    PubMed

    Lipfert, Susanne W; Günther, Michael; Renjewski, Daniel; Seyfarth, Andre

    2014-04-15

    Rapid unloading and a peak in power output of the ankle joint have been widely observed during push-off in human walking. Model-based studies hypothesize that this push-off causes redirection of the body center of mass just before touch-down of the leading leg. Other research suggests that work done by the ankle extensors provides kinetic energy for the initiation of swing. Also, muscle work is suggested to power a catapult-like action in late stance of human walking. However, there is a lack of knowledge about the biomechanical process leading to this widely observed high power output of the ankle extensors. In our study, we use kinematic and dynamic data of human walking collected at speeds between 0.5 and 2.5 m s(-1) for a comprehensive analysis of push-off mechanics. We identify two distinct phases, which divide the push-off: first, starting with positive ankle power output, an alleviation phase, where the trailing leg is alleviated from supporting the body mass, and second, a launching phase, where stored energy in the ankle joint is released. Our results show a release of just a small part of the energy stored in the ankle joint during the alleviation phase. A larger impulse for the trailing leg than for the remaining body is observed during the launching phase. Here, the buckling knee joint inhibits transfer of power from the ankle to the remaining body. It appears that swing initiation profits from an impulsive ankle push-off resulting from a catapult without escapement.

  18. Muscle activation during push-ups performed under stable and unstable conditions.

    PubMed

    Borreani, Sebastien; Calatayud, Joaquin; Colado, Juan Carlos; Moya-Nájera, Diego; Triplett, N Travis; Martin, Fernando

    2015-12-01

    The purpose of this study was to analyze muscle activation when performing push-ups under different stability conditions. Physically fit young male university students ( N  = 30) performed five push-ups under stable conditions (on the floor) and using four unstable devices (wobble board, stability disc, fitness dome, and the TRX Suspension Trainer). The push-up speed was controlled using a metronome, and the testing order was randomized. The average amplitudes of the electromyographic (EMG) root mean square of the anterior deltoid (DELT), serratus anterior (SERRA), lumbar multifidus (LUMB), and rectus femoris (FEM) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). No significant differences were found for the DELT [ F (4,112) = 1.978; p  = 0.130] among the conditions. However, statistically significant differences were found among the different conditions for the SERRA [ F (4,60) = 17.649; p  < 0.001], LUMB [ F (4,76) = 12.334; p  < 0.001], and FEM [ F (4,104) = 24.676; p  < 0.001] muscle activation. The suspended device was the only condition that elicited higher LUMB and FEM activation compared to the other conditions. Push-ups performed on the floor showed lower SERRA activation than those performed with all unstable devices. Not all unstable devices enhance muscle activation compared to traditional push-ups.

  19. Duration of Second Stage of Labour at Term and Pushing Time: Risk Factors for Postpartum Haemorrhage.

    PubMed

    Looft, Emelie; Simic, Marija; Ahlberg, Mia; Snowden, Jonathan M; Cheng, Yvonne W; Stephansson, Olof

    2017-03-01

    Prolonged labour is associated with increased risk of postpartum haemorrhage (PPH), but the role of active pushing time and the relation with management during labour remains poorly understood. A population-based cohort study from electronic medical record data in the Stockholm-Gotland Region, Sweden. We included 57 267 primiparous women with singleton, term gestation, livebirths delivered vaginally in cephalic presentation in 2008-14. We performed multivariable Poisson regression to estimate the association between length of second stage, pushing time, and PPH (estimated blood loss >500 mL during delivery), adjusting for maternal, delivery, and fetal characteristics as potential confounders. The incidence of PPH was 28.9%. The risk of PPH increased with each passing hour of second stage: compared with a second stage <1 h, the adjusted relative risk (RR) for PPH were for 1 to <2 h 1.10 (95% confidence interval (CI) 1.07, 1.14); for 2 to <3 h 1.15 (95% CI 1.10, 1.20); for 3 to <4 h 1.28 (95% CI 1.22, 1.33); and for ≥4 h 1.40 (95% CI 1.33, 1.46). PPH also increased with pushing time exceeding 30 min. Compared to pushing time between 15 and 29 min, the RR for PPH were for <15 min 0.98 (95% CI 0.94, 1.03); for 30-44 min 1.08 (95% CI 1.04, 1.12); for 45-59 min 1.11 (95% CI 1.06, 1.16); and for ≥60 min 1.20 (95% CI 1.15, 1.25). Increased length of second stage and pushing time during labour are both associated with increased risk of PPH. © 2017 John Wiley & Sons Ltd.

  20. An investigation of rugby scrimmaging posture and individual maximum pushing force.

    PubMed

    Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

    2007-02-01

    Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

  1. Push-pull tests for estimating effective porosity: expanded analytical solution and in situ application

    NASA Astrophysics Data System (ADS)

    Paradis, Charles J.; McKay, Larry D.; Perfect, Edmund; Istok, Jonathan D.; Hazen, Terry C.

    2017-10-01

    The analytical solution describing the one-dimensional displacement of the center of mass of a tracer during an injection, drift, and extraction test (push-pull test) was expanded to account for displacement during the injection phase. The solution was expanded to improve the in situ estimation of effective porosity. The truncated equation assumed displacement during the injection phase was negligible, which may theoretically lead to an underestimation of the true value of effective porosity. To experimentally compare the expanded and truncated equations, single-well push-pull tests were conducted across six test wells located in a shallow, unconfined aquifer comprised of unconsolidated and heterogeneous silty and clayey fill materials. The push-pull tests were conducted by injection of bromide tracer, followed by a non-pumping period, and subsequent extraction of groundwater. The values of effective porosity from the expanded equation (0.6-5.0%) were substantially greater than from the truncated equation (0.1-1.3%). The expanded and truncated equations were compared to data from previous push-pull studies in the literature and demonstrated that displacement during the injection phase may or may not be negligible, depending on the aquifer properties and the push-pull test parameters. The results presented here also demonstrated the spatial variability of effective porosity within a relatively small study site can be substantial, and the error-propagated uncertainty of effective porosity can be mitigated to a reasonable level (< ± 0.5%). The tests presented here are also the first that the authors are aware of that estimate, in situ, the effective porosity of fine-grained fill material.

  2. Push-pull tests for estimating effective porosity: expanded analytical solution and in situ application

    NASA Astrophysics Data System (ADS)

    Paradis, Charles J.; McKay, Larry D.; Perfect, Edmund; Istok, Jonathan D.; Hazen, Terry C.

    2018-03-01

    The analytical solution describing the one-dimensional displacement of the center of mass of a tracer during an injection, drift, and extraction test (push-pull test) was expanded to account for displacement during the injection phase. The solution was expanded to improve the in situ estimation of effective porosity. The truncated equation assumed displacement during the injection phase was negligible, which may theoretically lead to an underestimation of the true value of effective porosity. To experimentally compare the expanded and truncated equations, single-well push-pull tests were conducted across six test wells located in a shallow, unconfined aquifer comprised of unconsolidated and heterogeneous silty and clayey fill materials. The push-pull tests were conducted by injection of bromide tracer, followed by a non-pumping period, and subsequent extraction of groundwater. The values of effective porosity from the expanded equation (0.6-5.0%) were substantially greater than from the truncated equation (0.1-1.3%). The expanded and truncated equations were compared to data from previous push-pull studies in the literature and demonstrated that displacement during the injection phase may or may not be negligible, depending on the aquifer properties and the push-pull test parameters. The results presented here also demonstrated the spatial variability of effective porosity within a relatively small study site can be substantial, and the error-propagated uncertainty of effective porosity can be mitigated to a reasonable level (< ± 0.5%). The tests presented here are also the first that the authors are aware of that estimate, in situ, the effective porosity of fine-grained fill material.

  3. Fast Regulation of Vertical Squat Jump during Push-Off in Skilled Jumpers

    PubMed Central

    Fargier, Patrick; Massarelli, Raphael; Rabahi, Tahar; Gemignani, Angelo; Fargier, Emile

    2016-01-01

    The height of a maximum Vertical Squat Jump (VSJ) reflects the useful power produced by a jumper during the push-off phase. In turn this partly depends on the coordination of the jumper's segmental rotations at each instant. The physical system constituted by the jumper has been shown to be very sensitive to perturbations and furthermore the movement is realized in a very short time (ca. 300 ms), compared to the timing of known feedback loops. However, the dynamics of the segmental coordination and its efficiency in relation to energetics at each instant of the push-off phase still remained to be clarified. Their study was the main purpose of the present research. Eight young adult volunteers (males) performed maximal VSJ. They were skilled in jumping according to their sport activities (track and field or volleyball). A video analysis on the kinematics of the jump determined the influence of the jumpers' segments rotation on the vertical velocity and acceleration of the body mass center (MC). The efficiency in the production of useful power at the jumpers' MC level, by the rotation of the segments, was measured in consequence. The results showed a great variability in the segmental movements of the eight jumpers, but homogeneity in the overall evolution of these movements with three consecutive types of coordination in the second part of the push-off (lasting roughly 0.16 s). Further analyses gave insights on the regulation of the push-off, suggesting that very fast regulation(s) of the VSJ may be supported by: (a) the adaptation of the motor cerebral programming to the jumper's physical characteristics; (b) the control of the initial posture; and (c) the jumper's perception of the position of his MC relative to the ground reaction force, during push-off, to reduce energetic losses. PMID:27486404

  4. Direct-push geochemical profiling for assessment of inorganic chemical heterogeneity in aquifers

    USGS Publications Warehouse

    Schulmeister, M.K.; Healey, J.M.; Butler, J.J.; McCall, G.W.

    2004-01-01

    Discrete-depth sampling of inorganic groundwater chemistry is essential for a variety of site characterization activities. Although the mobility and rapid sampling capabilities of direct-push techniques have led to their widespread use for evaluating the distribution of organic contaminants, complementary methods for the characterization of spatial variations in geochemical conditions have not been developed. In this study, a direct-push-based approach for high-resolution inorganic chemical profiling was developed at a site where sharp chemical contrasts and iron-reducing conditions had previously been observed. Existing multilevel samplers (MLSs) that span a fining-upward alluvial sequence were used for comparison with the direct-push profiling. Chemical profiles obtained with a conventional direct-push exposed-screen sampler differed from those obtained with an adjacent MLS because of sampler reactivity and mixing with water from previous sampling levels. The sampler was modified by replacing steel sampling components with stainless-steel and heat-treated parts, and adding an adapter that prevents mixing. Profiles obtained with the modified approach were in excellent agreement with those obtained from an adjacent MLS for all constituents and parameters monitored (Cl, NO3, Fe, Mn, DO, ORP, specific conductance and pH). Interpretations of site redox conditions based on field-measured parameters were supported by laboratory analysis of dissolved Fe. The discrete-depth capability of this approach allows inorganic chemical variations to be described at a level of detail that has rarely been possible. When combined with the mobility afforded by direct-push rigs and on-site methods of chemical analysis, the new approach is well suited for a variety of interactive site-characterization endeavors. ?? 2003 Elsevier B.V. All rights reserved.

  5. Three Levels of Push-Pull Dynamics among Chinese International Students' Decision to Study Abroad in the Canadian Context

    ERIC Educational Resources Information Center

    Chen, Jun Mian

    2017-01-01

    The extant literature on student migration flows generally focus on the traditional push-pull factors of migration at the individual level. Such a tendency excludes the broader levels affecting international student mobility. This paper proposes a hybrid of three levels of push-pull dynamics (micro-individual decision-making, meso-academic…

  6. Challenges and breakthroughs in recent research on self-assembly

    PubMed Central

    Ariga, Katsuhiko; Hill, Jonathan P; Lee, Michael V; Vinu, Ajayan; Charvet, Richard; Acharya, Somobrata

    2008-01-01

    The controlled fabrication of nanometer-scale objects is without doubt one of the central issues in current science and technology. However, existing fabrication techniques suffer from several disadvantages including size-restrictions and a general paucity of applicable materials. Because of this, the development of alternative approaches based on supramolecular self-assembly processes is anticipated as a breakthrough methodology. This review article aims to comprehensively summarize the salient aspects of self-assembly through the introduction of the recent challenges and breakthroughs in three categories: (i) types of self-assembly in bulk media; (ii) types of components for self-assembly in bulk media; and (iii) self-assembly at interfaces. PMID:27877935

  7. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, Harry Lawrence; Elliott, Thomas S.

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  8. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L.; Elliott, Thomas S.

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  9. Photovoltaic self-assembly.

    SciTech Connect

    Lavin, Judith; Kemp, Richard Alan; Stewart, Constantine A.

    2010-10-01

    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilicmore » interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry.« less

  10. Assembly Test Article (ATA)

    NASA Technical Reports Server (NTRS)

    Ricks, Glen A.

    1988-01-01

    The assembly test article (ATA) consisted of two live loaded redesigned solid rocket motor (RSRM) segments which were assembled and disassembled to simulate the actual flight segment stacking process. The test assembly joint was flight RSRM design, which included the J-joint insulation design and metal capture feature. The ATA test was performed mid-November through 24 December 1987, at Kennedy Space Center (KSC), Florida. The purpose of the test was: certification that vertical RSRM segment mating and separation could be accomplished without any damage; verification and modification of the procedures in the segment stacking/destacking documents; and certification of various GSE to be used for flight assembly and inspection. The RSRM vertical segment assembly/disassembly is possible without any damage to the insulation, metal parts, or seals. The insulation J-joint contact area was very close to the predicted values. Numerous deviations and changes to the planning documents were made to ensure the flight segments are effectively and correctly stacked. Various GSE were also certified for use on flight segments, and are discussed in detail.

  11. Constrained space camera assembly

    DOEpatents

    Heckendorn, F.M.; Anderson, E.K.; Robinson, C.W.; Haynes, H.B.

    1999-05-11

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity is disclosed. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras. 17 figs.

  12. Some methods for achieving more efficient performance of fuel assemblies

    NASA Astrophysics Data System (ADS)

    Boltenko, E. A.

    2014-07-01

    More efficient operation of reactor plant fuel assemblies can be achieved through the use of new technical solutions aimed at obtaining more uniform distribution of coolant over the fuel assembly section, more intense heat removal on convex heat-transfer surfaces, and higher values of departure from nucleate boiling ratio (DNBR). Technical solutions using which it is possible to obtain more intense heat removal on convex heat-transfer surfaces and higher DNBR values in reactor plant fuel assemblies are considered. An alternative heat removal arrangement is described using which it is possible to obtain a significantly higher power density in a reactor plant and essentially lower maximal fuel rod temperature.

  13. Functional self-assembled lipidic systems derived from renewable resources.

    PubMed

    Silverman, Julian R; Samateh, Malick; John, George

    2016-01-01

    Self-assembled lipidic amphiphile systems can create a variety of multi-functional soft materials with value-added properties. When employing natural reagents and following biocatalytic syntheses, self-assembling monomers may be inherently designed for degradation, making them potential alternatives to conventional and persistent polymers. By using non-covalent forces, self-assembled amphiphiles can form nanotubes, fibers, and other stimuli responsive architectures prime for further applied research and incorporation into commercial products. By viewing these lipid derivatives under a lens of green principles, there is the hope that in developing a structure-function relationship and functional smart materials that research may remain safe, economic, and efficient.

  14. Multicriteria Analysis of Assembling Buildings from Steel Frame Structures

    NASA Astrophysics Data System (ADS)

    Miniotaite, Ruta

    2017-10-01

    Steel frame structures are often used in the construction of public and industrial buildings. They are used for: all types of slope roofs; walls of newly-built public and industrial buildings; load bearing structures; roofs of renovated buildings. The process of assembling buildings from steel frame structures should be analysed as an integrated process influenced by such factors as construction materials and machinery used, the qualification level of construction workers, complexity of work, available finance. It is necessary to find a rational technological design solution for assembling buildings from steel frame structures by conducting a multiple criteria analysis. The analysis provides a possibility to evaluate the engineering considerations and find unequivocal solutions. The rational alternative of a complex process of assembling buildings from steel frame structures was found through multiple criteria analysis and multiple criteria evaluation. In multiple criteria evaluation of technological solutions for assembling buildings from steel frame structures by pairwise comparison method the criteria by significance are distributed as follows: durability is the most important criterion in the evaluation of alternatives; the price (EUR/unit of measurement) of a part of assembly process; construction workers’ qualification level (category); mechanization level of a part of assembling process (%), and complexity of assembling work (in points) are less important criteria.

  15. Solar heating assembly

    SciTech Connect

    Netherton, O.E.

    1978-07-25

    A solar heating assembly including a radiant energy collector having a casing where fluid conduit is mounted therein in substantially suspended fashion relative to the interior space of the casing and angularly oriented, reflective wall surfaces disposed to essentially concentrate the radiant energy on the fluid conduit so as to heat the interior space of the casing and the fluid within the conduit. A brace frame is mounted on the ground or other surface and comprises a plurality of support columns wherein the casing is adjustably mounted adjacent the upper portions of the support columns and brace frame in spacedmore » relation to the ground. A plurality of exercise devices such as children's gym set are mounted in substantially suspended relation wherein the collector assembly of the solar heating assembly is used in combination with the brace frame which is specifically in the form of an exercise device or gym set.« less

  16. Liaison based assembly design

    SciTech Connect

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted,more » increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.« less

  17. Optical interconnect assembly

    DOEpatents

    Laughlin, Daric; Abel, Philip

    2015-06-09

    An optical assembly includes a substrate with a first row of apertures and a second row of apertures. A first optical die includes a first plurality of optical transducer elements and is mounted on the substrate such that an optical signal interface of each transducer element is aligned with an aperture of the first row of optical apertures. A second optical die includes a second plurality of optical transducer elements and is mounted on the substrate such that an optical signal interface of each of the second plurality of optical transducer elements is aligned with an aperture of the second row of optical apertures. A connector configured to mate with the optical assembly supports a plurality of optical fibers. A terminal end of each optical fiber protrudes from the connector and extends into one of the apertures when the connector is coupled with the optical assembly.

  18. Blade attachment assembly

    DOEpatents

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  19. Power module assembly

    DOEpatents

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  20. Power module assembly

    SciTech Connect

    Campbell, Jeremy B; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, andmore » a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.« less

  1. Supported PV module assembly

    DOEpatents

    Mascolo, Gianluigi; Taggart, David F.; Botkin, Jonathan D.; Edgett, Christopher S.

    2013-10-15

    A supported PV assembly may include a PV module comprising a PV panel and PV module supports including module supports having a support surface supporting the module, a module registration member engaging the PV module to properly position the PV module on the module support, and a mounting element. In some embodiments the PV module registration members engage only the external surfaces of the PV modules at the corners. In some embodiments the assembly includes a wind deflector with ballast secured to a least one of the PV module supports and the wind deflector. An array of the assemblies can be secured to one another at their corners to prevent horizontal separation of the adjacent corners while permitting the PV modules to flex relative to one another so to permit the array of PV modules to follow a contour of the support surface.

  2. Supported PV module assembly

    SciTech Connect

    Mascolo, Gianluigi; Taggart, David F.; Botkin, Jonathan D.

    2013-10-15

    A supported PV assembly may include a PV module comprising a PV panel and PV module supports including module supports having a support surface supporting the module, a module registration member engaging the PV module to properly position the PV module on the module support, and a mounting element. In some embodiments the PV module registration members engage only the external surfaces of the PV modules at the corners. In some embodiments the assembly includes a wind deflector with ballast secured to a least one of the PV module supports and the wind deflector. An array of the assemblies canmore » be secured to one another at their corners to prevent horizontal separation of the adjacent corners while permitting the PV modules to flex relative to one another so to permit the array of PV modules to follow a contour of the support surface.« less

  3. Blade attachment assembly

    SciTech Connect

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, andmore » retains the blade in the adaptor member, and the assembly in the rotor wheel.« less

  4. The Effect of Variation of Plyometric Push-Ups on Force-Application Kinetics and Perception of Intensity.

    PubMed

    Dhahbi, Wissem; Chaouachi, Anis; Dhahbi, Anis Ben; Cochrane, Jodie; Chèze, Laurence; Burnett, Angus; Chamari, Karim

    2017-02-01

    To examine differences between ground-reaction-force (GRF)-based parameters collected from 5 types of plyometric push-ups. Between-trials reliability and the relationships between parameters were also assessed. Thirty-seven highly active commando soldiers performed 3 trials of 5 variations of the plyometric push-up in a counterbalanced order: standard countermovement push-up (SCPu), standard squat push-up (SSPu), kneeling countermovement push-up (KCPu), kneeling squat push-up (KSPu), and drop-fall push-up (DFPu). Vertical GRF was measured during these exercises using a portable Kistler force plate. The GRF applied by the hands in the starting position (initial force supported), peak GRF and rate of force development during takeoff, flight time, impact force, and rate of force development impact on landing were determined. During standard-position exercises (SCPu and SSPu) the initial force supported and impact force were higher (P < .001) than with kneeling exercises (KCPu, KSPu, and DFPu). The peak GRF and rate of force development during takeoff were higher (P < .001) in the countermovement push-up exercises ([CMP] SCPu, KCPu, and DFPu) than squat push-up exercises ([SP] SSPu and KSPu). Furthermore, the flight time was greater (P < .001) during kneeling exercises than during standard-position exercises. A significant relationship (P < .01) between impact force and the rate of force development impact was observed for CMP and SP exercises (r = .83 and r = .62, respectively). The initial force supported was also negatively related (P < .01) to the flight time for both CMP and SP (r = -.74 and r = -.80, respectively). It was revealed that the initial force supported and the peak GRF during takeoff had excellent reliability; however, other parameters had poor absolute reliability. It is possible to adjust the intensity of plyometric push-up exercises and train athletes' muscle power by correctly interpreting GRF-based parameters. However, caution is required as some

  5. Self assembling proteins

    DOEpatents

    Yeates, Todd O.; Padilla, Jennifer; Colovos, Chris

    2004-06-29

    Novel fusion proteins capable of self-assembling into regular structures, as well as nucleic acids encoding the same, are provided. The subject fusion proteins comprise at least two oligomerization domains rigidly linked together, e.g. through an alpha helical linking group. Also provided are regular structures comprising a plurality of self-assembled fusion proteins of the subject invention, and methods for producing the same. The subject fusion proteins find use in the preparation of a variety of nanostructures, where such structures include: cages, shells, double-layer rings, two-dimensional layers, three-dimensional crystals, filaments, and tubes.

  6. Flow Cage Assemblies

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Bar-Cohen, Yoseph (Inventor)

    2017-01-01

    Apparatus, systems and methods for implementing flow cages and flow cage assemblies in association with high pressure fluid flows and fluid valves are provided. Flow cages and flow assemblies are provided to dissipate the energy of a fluid flow, such as by reducing fluid flow pressure and/or fluid flow velocity. In some embodiments the dissipation of the fluid flow energy is adapted to reduce erosion, such as from high-pressure jet flows, to reduce cavitation, such as by controllably increasing the flow area, and/or to reduce valve noise associated with pressure surge.

  7. Lightweight reflector assembly

    NASA Technical Reports Server (NTRS)

    Argoud, M. J.; Jolley, J.; Walker, W. L. (Inventor)

    1977-01-01

    An inexpensive, lightweight reflective assembly member having good optical quality and particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors is described. The reflective assembly consists of a thin sheet of glass with appropriate reflective coating and a cellular glass block substrate bonded together. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface. An adhesive is applied to the abraded surface and a lamina reflective surface is placed under a uniform pressure to conform the reflective surface onto the desired abraded surface of the substrate.

  8. Hand Controller Assembly

    NASA Technical Reports Server (NTRS)

    Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

    2015-01-01

    A user input device for a vehicular electrical system is provided. The user input device includes a handle sized and shaped to be gripped by a human hand and a gimbal assembly within the handle. The gimbal assembly includes a first gimbal component, a second gimbal component coupled to the first gimbal component such that the second gimbal component is rotatable relative to the first gimbal component about a first axis, and a third gimbal component coupled to the second gimbal component such that the third gimbal component is rotatable relative to the second gimbal component about a second axis.

  9. Assembling RNA Nanoparticles.

    PubMed

    Xiao, Shou-Jun

    2017-01-01

    RNA nanoparticles are designed and self-assembled according to noncanonical interactions of naturally conserved RNA motifs and/or canonical Watson-Crick base-pairing interactions, which have potential applications in gene therapy and nanomedicine. These artificially engineered nanoparticles are mainly synthesized from in vitro transcribed RNAs, purified by denaturing and native polyacrylamide gel electrophoresis (PAGE), and characterized with native PAGE, AFM, and TEM technologies. The protocols of in vitro transcription, denaturing and native PAGE, and RNA nanoparticle self-assembly are described in detail.

  10. Assembling an aesthetic.

    PubMed

    Candela, Emily

    2012-12-01

    Recent research informing and related to the study of three-dimensional scientific models is assembled here in a way that explores an aesthetic, specifically, of touch. I concentrate on the materiality of models, drawing on insights from the history and philosophy of science, design and metaphysics. This article chronicles the ways in which touch, or material interactions, operate in the world of 3D models, and its role in what models mean and do. I end with a call for greater attention to scientific process, described as assembly of and within science, which is revealed by this focus on touch. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Reverse breech extraction versus the standard approach of pushing the impacted fetal head up through the vagina in caesarean section for obstructed labour: A randomised controlled trial.

    PubMed

    Nooh, Ahmed Mohamed; Abdeldayem, Hussein Mohammed; Ben-Affan, Othman

    2017-05-01

    The objective of this study was to assess effectiveness and safety of the reverse breech extraction approach in Caesarean section for obstructed labour, and compare it with the standard approach of pushing the fetal head up through the vagina. This randomised controlled trial included 192 women. In 96, the baby was delivered by the 'reverse breech extraction approach', and in the remaining 96, by the 'standard approach'. Extension of uterine incision occurred in 18 participants (18.8%) in the reverse breech extraction approach group, and 46 (47.9%) in the standard approach group (p = .0003). Two women (2.1%) in the reverse breech extraction approach group needed blood transfusion and 11 (11.5%) in the standard approach group (p = .012). Pyrexia developed in 3 participants (3.1%) in the reverse breech extraction approach group, and 19 (19.8%) in the standard approach group (p = .0006). Wound infection occurred in 2 women (2.1%) in the reverse breech extraction approach group, and 12 (12.5%) in the standard approach group (p = .007). Apgar score <7 at 5 minutes was noted in 8 babies (8.3%) in the reverse breech extraction approach group, and 21 (21.9%) in the standard approach group (p = .015). In conclusion, reverse breech extraction in Caesarean section for obstructed labour is an effective and safe alternative to the standard approach of pushing the fetal head up through the vagina.

  12. Directed assembly-based printing of homogeneous and hybrid nanorods using dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Chai, Zhimin; Yilmaz, Cihan; Busnaina, Ahmed A.; Lissandrello, Charles A.; Carter, David J. D.

    2017-11-01

    Printing nano and microscale three-dimensional (3D) structures using directed assembly of nanoparticles has many potential applications in electronics, photonics and biotechnology. This paper presents a reproducible and scalable 3D dielectrophoresis assembly process for printing homogeneous silica and hybrid silica/gold nanorods from silica and gold nanoparticles. The nanoparticles are assembled into patterned vias under a dielectrophoretic force generated by an alternating current (AC) field, and then completely fused in situ to form nanorods. The assembly process is governed by the applied AC voltage amplitude and frequency, pattern geometry, and assembly time. Here, we find out that complete assembly of nanorods is not possible without applying both dielectrophoresis and electrophoresis. Therefore, a direct current offset voltage is used to add an additional electrophoretic force to the assembly process. The assembly can be precisely controlled to print silica nanorods with diameters from 20-200 nm and spacing from 500 nm to 2 μm. The assembled nanorods have good uniformity in diameter and height over a millimeter scale. Besides homogeneous silica nanorods, hybrid silica/gold nanorods are also assembled by sequentially assembling silica and gold nanoparticles. The precision of the assembly process is further demonstrated by assembling a single particle on top of each nanorod to demonstrate an additional level of functionalization. The assembled hybrid silica/gold nanorods have potential to be used for metamaterial applications that require nanoscale structures as well as for plasmonic sensors for biosensing applications.

  13. Directed assembly-based printing of homogeneous and hybrid nanorods using dielectrophoresis.

    PubMed

    Chai, Zhimin; Yilmaz, Cihan; Busnaina, Ahmed A; Lissandrello, Charles A; Carter, David J D

    2017-11-24

    Printing nano and microscale three-dimensional (3D) structures using directed assembly of nanoparticles has many potential applications in electronics, photonics and biotechnology. This paper presents a reproducible and scalable 3D dielectrophoresis assembly process for printing homogeneous silica and hybrid silica/gold nanorods from silica and gold nanoparticles. The nanoparticles are assembled into patterned vias under a dielectrophoretic force generated by an alternating current (AC) field, and then completely fused in situ to form nanorods. The assembly process is governed by the applied AC voltage amplitude and frequency, pattern geometry, and assembly time. Here, we find out that complete assembly of nanorods is not possible without applying both dielectrophoresis and electrophoresis. Therefore, a direct current offset voltage is used to add an additional electrophoretic force to the assembly process. The assembly can be precisely controlled to print silica nanorods with diameters from 20-200 nm and spacing from 500 nm to 2 μm. The assembled nanorods have good uniformity in diameter and height over a millimeter scale. Besides homogeneous silica nanorods, hybrid silica/gold nanorods are also assembled by sequentially assembling silica and gold nanoparticles. The precision of the assembly process is further demonstrated by assembling a single particle on top of each nanorod to demonstrate an additional level of functionalization. The assembled hybrid silica/gold nanorods have potential to be used for metamaterial applications that require nanoscale structures as well as for plasmonic sensors for biosensing applications.

  14. Fire resistant PV shingle assembly

    DOEpatents

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  15. Effects of Different Relative Loads on Power Performance During the Ballistic Push-up.

    PubMed

    Wang, Ran; Hoffman, Jay R; Sadres, Eliahu; Bartolomei, Sandro; Muddle, Tyler W D; Fukuda, David H; Stout, Jeffrey R

    2017-12-01

    Wang, R, Hoffman, JR, Sadres, E, Bartolomei, S, Muddle, TWD, Fukuda, DH, and Stout, JR. Effects of different relative loads on power performance during the ballistic push-up. J Strength Cond Res 31(12): 3411-3416, 2017-The purpose of this investigation was to examine the effect of load on force and power performance during a ballistic push-up. Sixty (24.5 ± 4.3 years, 1.75 ± 0.07 m, and 80.8 ± 13.5 kg) recreationally active men who participated in this investigation completed all testing and were included in the data analysis. All participants were required to perform a 1 repetition maximum bench press, and ballistic push-ups without external load (T1), with 10% (T2) and 20% (T3) of their body mass. Ballistic push-ups during T2 and T3 were performed using a weight loaded vest. Peak and mean force, power, as well as net impulse and flight time were determined for each ballistic push-up. Peak and mean force were both significantly greater (p < 0.01) during T3 (1,062 ± 202 and 901 ± 154 N, respectively), than both T2 (1,017 ± 202 and 842 ± 151 N, respectively) and T1 (960 ± 188 and 792 ± 140 N, respectively). Peak and mean power were significantly greater (p < 0.01) during T1 (950 ± 257 and 521 ± 148 W, respectively), than both T2 (872 ± 246 and 485 ± 143 W, respectively) and T3 (814 ± 275 and 485 ± 162 W, respectively). Peak and mean power were greatest during T1, regardless of participants' strength levels. Significant (p < 0.01) greater net impulse and smaller peak velocity and flight time were also noted from T1 to T3. Results of this investigation indicated that maximal power outputs were achieved without the use of an external load when performing the ballistic push-up, regardless of the participants' level of strength.

  16. Photoinduced intramolecular charge transfer in push-pull polyenes: effects of solvation, electron-donor group, and polyenic chain length.

    PubMed

    Akemann, Walther; Laage, Damien; Plaza, Pascal; Martin, Monique M; Blanchard-Desce, Mireille

    2008-01-17

    Subpicosecond absorption spectroscopy is used to characterize the primary photoinduced processes in a class of push-pull polyenes bearing a julolidine end group as the electron donor and a diethylthiobarbituric acid end group as the electron acceptor. The excited-state decay time and relaxation pathway have been studied for four polyenes of increasing chain length (n = 2-5 double bonds) in aprotic solvents of different solvation time, polarity, and viscosity. Intramolecular charge transfer (ICT) leading to a transient state of cyanine-like structure (fully conjugated with no bond length alternation) is observed in all polar solvents at a solvent dependent rate, but the reaction is not observed in cyclohexane, a nonpolar solvent. In polar solvents, the reaction time increases with the average solvation time but remains slightly larger, except in the viscous solvent triacetin. These facts are interpreted as an indication that both solvent reorganization and internal restructuring are involved in the ICT-state formation. The observed photodynamics resemble those we previously found for another class of polyenes bearing a dibutylaniline group as the donor, including a similar charge-transfer rate in spite of the larger electron donor character of the julolidine group. This observation brings further support to the proposal that an intramolecular coordinate is involved in the charge-transfer reaction, possibly a torsional motion of the donor end group. On the other hand, relaxation of the ICT state leads to cis-trans isomerization or crossing to the triplet state, depending on the length of the polyenic chain. In dioxane, tetrahydrofuran, and triacetin, the ICT state of the shorter chains (n = 2, 3) relaxes to the isomer with a viscosity-dependent rate, while that of the longer ones (n = 4, 5) leads to the triplet state with a viscosity-independent rate, as expected. In acetonitrile, the ICT-state lifetime is generally much shorter. A change from photoisomerization to

  17. Assembly of long error-prone reads using de Bruijn graphs

    PubMed Central

    Lin, Yu; Yuan, Jeffrey; Kolmogorov, Mikhail; Shen, Max W.; Chaisson, Mark; Pevzner, Pavel A.

    2016-01-01

    The recent breakthroughs in assembling long error-prone reads were based on the overlap-layout-consensus (OLC) approach and did not utilize the strengths of the alternative de Bruijn graph approach to genome assembly. Moreover, these studies often assume that applications of the de Bruijn graph approach are limited to short and accurate reads and that the OLC approach is the only practical paradigm for assembling long error-prone reads. We show how to generalize de Bruijn graphs for assembling long error-prone reads and describe the ABruijn assembler, which combines the de Bruijn graph and the OLC approaches and results in accurate genome reconstructions. PMID:27956617

  18. Turbomachine blade assembly

    DOEpatents

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  19. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L.; Schroeder, John E.; Kalsi, Manmohan S.; Alvarez, Patricio D.

    2010-09-21

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  20. Rotary shaft sealing assembly

    DOEpatents

    Dietle, Lannie L; Schroeder, John E; Kalsi, Manmohan S; Alvarez, Patricio D

    2013-08-13

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaft sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.

  1. Metaphase Spindle Assembly

    PubMed Central

    Kapoor, Tarun M.

    2017-01-01

    A microtubule-based bipolar spindle is required for error-free chromosome segregation during cell division. In this review I discuss the molecular mechanisms required for the assembly of this dynamic micrometer-scale structure in animal cells. PMID:28165376

  2. Biosynthesis: Reprogramming assembly lines

    NASA Astrophysics Data System (ADS)

    Menon, Binuraj R. K.; Jenner, Matthew

    2018-03-01

    Rational engineering of biosynthetic assembly lines for production of new compounds is an attractive prospect, yet it presents many challenges. Learning from biology, some of the rules for expanding the chemical diversity of non-ribosomal peptides have been uncovered in two recent studies.

  3. Compression test assembly

    NASA Technical Reports Server (NTRS)

    Kariotis, A. H. (Inventor)

    1973-01-01

    A compression test assembly is described which prevents buckling of small diameter rigid specimens undergoing compression testing and permits attachment of extensometers for strain measurements. The test specimen is automatically aligned and laterally supported when compressive force is applied to the end caps and transmitted to the test specimen during testing.

  4. Segmented stator assembly

    DOEpatents

    Lokhandwalla, Murtuza; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Shah, Manoj Ramprasad; Quirion, Owen Scott

    2013-04-02

    An electric machine and stator assembly are provided that include a continuous stator portion having stator teeth, and a tooth tip portion including tooth tips corresponding to the stator teeth of the continuous stator portion, respectively. The tooth tip portion is mounted onto the continuous stator portion.

  5. NEUTRONIC REACTOR BURIAL ASSEMBLY

    DOEpatents

    Treshow, M.

    1961-05-01

    A burial assembly is shown whereby an entire reactor core may be encased with lead shielding, withdrawn from the reactor site and buried. This is made possible by a five-piece interlocking arrangement that may be easily put together by remote control with no aligning of bolt holes or other such close adjustments being necessary.

  6. Nanotechnology: A molecular assembler

    NASA Astrophysics Data System (ADS)

    Kelly, T. Ross; Snapper, Marc L.

    2017-09-01

    The idea of nanometre-scale machines that can assemble molecules has long been thought of as the stuff of science fiction. Such a machine has now been built -- and might herald a new model for organic synthesis. See Letter p.374

  7. Modeling Protein Self Assembly

    ERIC Educational Resources Information Center

    Baker, William P.; Jones, Carleton Buck; Hull, Elizabeth

    2004-01-01

    Understanding the structure and function of proteins is an important part of the standards-based science curriculum. Proteins serve vital roles within the cell and malfunctions in protein self assembly are implicated in degenerative diseases. Experience indicates that this topic is a difficult one for many students. We have found that the concept…

  8. Walking boot assembly

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.; Chambers, A. B.; Stjohn, R. H. (Inventor)

    1977-01-01

    A walking boot assembly particularly suited for use with a positively pressurized spacesuit is presented. A bootie adapted to be secured to the foot of a wearer, an hermetically sealed boot for receiving the bootie having a walking sole, an inner sole, and an upper portion adapted to be attached to an ankle joint of a spacesuit, are also described.

  9. Rotary shaft sealing assembly

    SciTech Connect

    Dietle, Lannie L; Schroeder, John E; Kalsi, Manmohan S

    2013-08-13

    A rotary shaft sealing assembly in which a first fluid is partitioned from a second fluid in a housing assembly having a rotary shaft located at least partially within. In one embodiment a lip seal is lubricated and flushed with a pressure-generating seal ring preferably having an angled diverting feature. The pressure-generating seal ring and a hydrodynamic seal may be used to define a lubricant-filled region with each of the seals having hydrodynamic inlets facing the lubricant-filled region. Another aspect of the sealing assembly is having a seal to contain pressurized lubricant while withstanding high rotary speeds. Another rotary shaftmore » sealing assembly embodiment includes a lubricant supply providing a lubricant at an elevated pressure to a region between a lip seal and a hydrodynamic seal with a flow control regulating the flow of lubricant past the lip seal. The hydrodynamic seal may include an energizer element having a modulus of elasticity greater than the modulus of elasticity of a sealing lip of the hydrodynamic seal.« less

  10. Dump valve assembly

    DOEpatents

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  11. Beyond the Assembly Line.

    ERIC Educational Resources Information Center

    Weitz, Rebecca; Guild, Todd

    1985-01-01

    Describes how Hughes Aircraft trainers followed four steps in meeting the challenges of a flexible manufacturing environment: needs assessment, design strategy, pilot evaluation, and follow-through. Within this environment, 50 self-paced training products were developed for one of the company's wire and back plane harness assembly departments. (CT)

  12. Admission mixing duct assembly

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor); Dunbar, Lawrence W. (Inventor)

    1995-01-01

    A variable cycle jet engine is provided with a mixing duct assembly which mixes core engine exhaust gas with bypass air when the engine is operating in a turbofan mode and which blocks flow from the core engine and isolates the core engine from the bypass flow when the engine is operating as a ramjet.

  13. Evaluation of Generation Alternation Models in Evolutionary Robotics

    NASA Astrophysics Data System (ADS)

    Oiso, Masashi; Matsumura, Yoshiyuki; Yasuda, Toshiyuki; Ohkura, Kazuhiro

    For efficient implementation of Evolutionary Algorithms (EA) to a desktop grid computing environment, we propose a new generation alternation model called Grid-Oriented-Deletion (GOD) based on comparison with the conventional techniques. In previous research, generation alternation models are generally evaluated by using test functions. However, their exploration performance on the real problems such as Evolutionary Robotics (ER) has not been made very clear yet. Therefore we investigate the relationship between the exploration performance of EA on an ER problem and its generation alternation model. We applied four generation alternation models to the Evolutionary Multi-Robotics (EMR), which is the package-pushing problem to investigate their exploration performance. The results show that GOD is more effective than the other conventional models.

  14. Atomic force microscopy nanomanipulation of shape persistent, spherical, self-assembled aggregates of gold nanoparticles.

    PubMed

    van Herrikhuyzen, Jeroen; Willems, Ron; George, Subi J; Flipse, Cees; Gielen, Jeroen C; Christianen, Peter C M; Schenning, Albertus P H J; Meskers, Stefan C J

    2010-11-23

    Gold (Au) nanoparticles have been synthesized that are stabilized by an organic ligand bearing a dithiolane functional group for binding to Au, an oligo(p-phenylene vinylene) (OPV) chromophoric group to drive self-assembly via π-π interactions, and a hydroxy functionality for interparticle hydrogen bonding. The OPV-Au particles reversibly self-assemble in n-heptane solution, forming shape persistent, spherical, nanometer-sized aggregates that do not collapse on a substrate. Optical absorption and transmission electron microscopy tomography studies show that the size and shape persistency can be tuned by modification of the ligands, adjustment of the core size, and variation of the concentration. The spherical assemblies can be manipulated with the tip of an atomic force microscope: an aggregate can be pushed over the surface for at least 20 times with nanometer precision and without substantial loss of material.

  15. Characterization of assembled MEMS

    NASA Astrophysics Data System (ADS)

    Jandric, Zoran; Randall, John N.; Saini, Rahul; Nolan, Michael; Skidmore, George

    2005-01-01

    Zyvex is developing a low-cost high-precision method for manufacturing MEMS-based three-dimensional structures/assemblies. The assembly process relies on compliant properties of the interconnecting components. The sockets and connectors are designed to benefit from their compliant nature by allowing the mechanical component to self-align, i.e. reposition themselves to their designed, stable position, independent of the initial placement of the part by the external robot. Thus, the self-aligning property guarantees the precision of the assembled structure to be very close to, or the same, as the precision of the lithography process itself. A three-dimensional (3D) structure is achieved by inserting the connectors into the sockets through the use of a passive end-effector. We have developed the automated, high-yield, assembly procedure which permits connectors to be picked up from any location within the same die, or a separate die. This general procedure allows for the possibility to assemble parts of dissimilar materials. We have built many 3D MEMS structures, including several 3D MEMS devices such as a scanning electron microscope (SEM) micro column, mass-spectrometer column, variable optical attenuator. For these 3D MEMS structures we characterize their mechanical strength through finite element simulation, dynamic properties by finite-element analysis and experimentally with UMECH"s MEMS motion analyzer (MMA), alignment accuracy by using an in-house developed dihedral angle measurement laser autocollimator, and impact properties by performing drop tests. The details of the experimental set-ups, the measurement procedures, and the experimental data are presented in this paper.

  16. Characterization of assembled MEMS

    NASA Astrophysics Data System (ADS)

    Jandric, Zoran; Randall, John N.; Saini, Rahul; Nolan, Michael; Skidmore, George

    2004-12-01

    Zyvex is developing a low-cost high-precision method for manufacturing MEMS-based three-dimensional structures/assemblies. The assembly process relies on compliant properties of the interconnecting components. The sockets and connectors are designed to benefit from their compliant nature by allowing the mechanical component to self-align, i.e. reposition themselves to their designed, stable position, independent of the initial placement of the part by the external robot. Thus, the self-aligning property guarantees the precision of the assembled structure to be very close to, or the same, as the precision of the lithography process itself. A three-dimensional (3D) structure is achieved by inserting the connectors into the sockets through the use of a passive end-effector. We have developed the automated, high-yield, assembly procedure which permits connectors to be picked up from any location within the same die, or a separate die. This general procedure allows for the possibility to assemble parts of dissimilar materials. We have built many 3D MEMS structures, including several 3D MEMS devices such as a scanning electron microscope (SEM) micro column, mass-spectrometer column, variable optical attenuator. For these 3D MEMS structures we characterize their mechanical strength through finite element simulation, dynamic properties by finite-element analysis and experimentally with UMECH"s MEMS motion analyzer (MMA), alignment accuracy by using an in-house developed dihedral angle measurement laser autocollimator, and impact properties by performing drop tests. The details of the experimental set-ups, the measurement procedures, and the experimental data are presented in this paper.

  17. Are single-well "push-pull" tests suitable tracer methods for aquifer characterization?

    NASA Astrophysics Data System (ADS)

    Hebig, Klaus; Zeilfelder, Sarah; Ito, Narimitsu; Machida, Isao; Scheytt, Traugott; Marui, Atsunao

    2013-04-01

    Recently, investigations were conducted for geological and hydrogeological characterisation of the sedimentary coastal basin of Horonobe (Hokkaido, Japan). Coastal areas are typical geological settings in Japan, which are less tectonically active than the mountain ranges. In Asia, and especially in Japan, these areas are often densely populated. Therefore, it is important to investigate the behaviour of solutes in such unconsolidated aquifers. In such settings sometimes only single boreholes or groundwater monitoring wells are available for aquifer testing for various reasons, e.g. depths of more than 100 m below ground level and slow groundwater velocities due to density driven flow. A standard tracer test with several involved groundwater monitoring wells is generally very difficult or even not possible at these depths. One of the most important questions in our project was how we can obtain information about chemical and hydraulic properties in such aquifers. Is it possible to characterize solute transport behaviour parameters with only one available groundwater monitoring well or borehole? A so-called "push-pull" test may be one suitable method for aquifer testing with only one available access point. In a push-pull test a known amount of several solutes including a conservative tracer is injected into the aquifer ("push") and afterwards extracted ("pull"). The measured breakthrough curve during the pumping back phase can then be analysed. This method has already been used previously with various aims, also in the recent project (e.g. Hebig et al. 2011, Zeilfelder et al. 2012). However, different test setups produced different tracer breakthrough curves. As no systematic evaluation of this aquifer tracer test method was done so far, nothing is known about its repeatability. Does the injection and extraction rate influence the shape of the breakthrough curve? Which role plays the often applied "chaser", which is used to push the test solution out from the

  18. Unified HBT base push-out and base-collector capacitance model

    NASA Astrophysics Data System (ADS)

    Davis, R. G.; Allenson, M. B.

    1995-02-01

    The presence of electron space-charge in the collector region of a transistor has the effect of offsetting the collector doping thereby giving a reduced effective doping concentration. This effect can modify the base-collector junction capacitance and for high current densities will give rise to base push-out. This paper describes the implementation of a unified junction capacitance and push-out model for the microwave HBT biased in the forward active mode. The threshold functions for pushout and full collector depletion are given and their significance for device and circuit design is discussed. An approximate description of the effect of pushout on the HBT forward time constant is described which accounts for the substantially increased diffusion constant in the pushout region.

  19. Push-Pull-Tests in einer isolierten Einzelkluft - Geländeversuche und numerische Modellierung

    NASA Astrophysics Data System (ADS)

    Orilski, Judith; Wohnlich, Stefan

    2017-11-01

    Push-pull tests are a proven method for determining hydraulic parameters if there is only one borehole available. Test interpretation by numerical models is often coupled with difficulties due to the heterogeneity of the subsurface. In this field study, tracer-based push-pull-tests (using Eosin, Tinopal and chloride) were performed in an isolated fracture in sandstone. The empirical breakthrough curves were compared to those of an idealized numerical single-fracture model. The influence of individual transport and test properties was previously investigated by a sensitivity study. A simplified analytical method served to determine further transport properties. The idealized fracture was realized by a porosity of one, the tracer dilution in the borehole could be considered by a special input function. It was shown that the peak form caused by advective dominated processes could be reproduced quite well by the numerical model, whereas the tailing due to dispersive-diffusive processes could not be considered sufficiently accurate.

  20. Store operation with conditional push of a tag value to a queue

    SciTech Connect

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-07-28

    According to one embodiment, a method for a store operation with a conditional push of a tag value to a queue is provided. The method includes configuring a queue that is accessible by an application, setting a value at an address in a memory device including a memory and a controller, receiving a request for an operation using the value at the address and performing the operation. The method also includes the controller writing a result of the operation to the address, thus changing the value at the address, the controller determining if the result of the operation meets amore » condition and the controller pushing a tag value to the queue based on the condition being met, where the tag value in the queue indicates to the application that the condition is met.« less

  1. EVALUATION OF SHEAR RESISTANCE OF PERFOBOND STRIP BASED ON SIMPLE PUSH-OUT TEST

    NASA Astrophysics Data System (ADS)

    Nakajima, Akinori; Koseki, Soichiro; Hashimoto, Masatoshi; Suzuki, Yasuo; Nguyen, Minh Hai

    A perfobond strip is generally used as the shear connector in the various steel-concrete hybrid structures and a few design formulas for evaluating the shear resistance of the perfobond strip are proposed. However, these design formulas are not always applicable to the one employed in the steel-concrete rigid frame bridge, since the formulas are established based on the standard push-out specimen for the stud shear connector in which some cracks may occur in the concrete block of the specimen during the test. In this paper, the shear resistance of the perfobond strip are examined experimentally by employing the simple push-out specimen different from the standard one for the stud shear connector. As a result, the design formula is proposed for evaluating the shear resistance of the perfobond strip taking into account the proportion of the concrete block as well as the perforation size and the concrete compressive strength.

  2. Particle Engulfment and Pushing By Solidifying Interfaces - Recent Theoretical and Experimental Developments

    NASA Technical Reports Server (NTRS)

    Stefanescu, D. M.; Catalina, A. V.; Juretzko, Frank R.; Sen, Subhayu; Curreri, P. A.

    2003-01-01

    The objective of the work on Particle Engulfment and Pushing by Solidifying Interfaces (PEP) include: 1) to obtain fundamental understanding of the physics of particle pushing and engulfment, 2) to develop mathematical models to describe the phenomenon, and 3) to perform critical experiments in the microgravity environment of space to provide benchmark data for model validation. Successful completion of this project will yield vital information relevant to a diverse area of terrestrial applications. With PEP being a long term research effort, this report will focus on advances in the theoretical treatment of the solid/liquid interface interaction with an approaching particle, experimental validation of some aspects of the developed models, and the experimental design aspects of future experiments to be performed on board the International Space Station.

  3. Store operation with conditional push of a tag value to a queue

    DOEpatents

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-07-28

    According to one embodiment, a method for a store operation with a conditional push of a tag value to a queue is provided. The method includes configuring a queue that is accessible by an application, setting a value at an address in a memory device including a memory and a controller, receiving a request for an operation using the value at the address and performing the operation. The method also includes the controller writing a result of the operation to the address, thus changing the value at the address, the controller determining if the result of the operation meets a condition and the controller pushing a tag value to the queue based on the condition being met, where the tag value in the queue indicates to the application that the condition is met.

  4. Technology Push

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2008-01-01

    When students, teachers, administrators and others employed in education arrive at work every day on thousands of campuses across the nation, it should come as no surprise that at every step along the way, technology is there to greet them. Technological advancements in education, as well as in facilities operation and management, are not a…

  5. Pushing Plastic

    ERIC Educational Resources Information Center

    Humphrey, John H.

    2007-01-01

    As they send their teenagers off to college, parents will counsel them on the dangers of accepting credit card offers and the risks inherent in credit card debt. Most assume that the university will be their ally in warning students about such dangers. But instead, most universities try to get their own students to take out a credit card. In this…

  6. SPRUCE S1 Bog Peat Depth Determined by Push Probe and GPR: 2009-2010

    DOE Data Explorer

    Slater, L. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.; Hook, L. A. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A.

    2012-01-01

    This data set reports the thickness of peat for the S1 Bog measured directly with manual push probes on September 21 and 22, 2009, and measured by ground penetrating radar (GPR) across transects from January 26 to February 2, 2010 and June 2 to June 9, 2010. Also included are interpolated values of peat depth from both probe and GPR data for the S1 Bog at 1 meter square horizontal resolution.

  7. Direct push driven in situ color logging tool (CLT): technique, analysis routines, and application

    NASA Astrophysics Data System (ADS)

    Werban, U.; Hausmann, J.; Dietrich, P.; Vienken, T.

    2014-12-01

    Direct push technologies have recently seen a broad development providing several tools for in situ parameterization of unconsolidated sediments. One of these techniques is the measurement of soil colors - a proxy information that reveals to soil/sediment properties. We introduce the direct push driven color logging tool (CLT) for real-time and depth-resolved investigation of soil colors within the visible spectrum. Until now, no routines exist on how to handle high-resolved (mm-scale) soil color data. To develop such a routine, we transform raw data (CIEXYZ) into soil color surrogates of selected color spaces (CIExyY, CIEL*a*b*, CIEL*c*h*, sRGB) and denoise small-scale natural variability by Haar and Daublet4 wavelet transformation, gathering interpretable color logs over depth. However, interpreting color log data as a single application remains challenging. Additional information, such as site-specific knowledge of the geological setting, is required to correlate soil color data to specific layers properties. Hence, we exemplary provide results from a joint interpretation of in situ-obtained soil color data and 'state-of-the-art' direct push based profiling tool data and discuss the benefit of additional data. The developed routine is capable of transferring the provided information obtained as colorimetric data into interpretable color surrogates. Soil color data proved to correlate with small-scale lithological/chemical changes (e.g., grain size, oxidative and reductive conditions), especially when combined with additional direct push vertical high resolution data (e.g., cone penetration testing and soil sampling). Thus, the technique allows enhanced profiling by means of providing another reproducible high-resolution parameter for analysis subsurface conditions. This opens potential new areas of application and new outputs for such data in site investigation. It is our intention to improve color measurements by means method of application and data

  8. Push-Pull Tests for Evaluating the Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons

    DTIC Science & Technology

    2006-09-01

    capability to transform the surrogate compound (e.g., isobutene ) and both cis-DCE and trans-1,2-dichloroethene (trans-DCE). Isobutene was transformed to... isobutene oxide, indicating transformation by a toluene ortho- monooxygenase, and both cis-DCE and trans-DCE were added to the injected fluid and were...transformed at similar rates. Similar rates of toluene utilization, cis-DCE, and isobutene transformation were achieved using the push-pull activity

  9. Push-Pull Tests for Evaluating the Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons: Cost & Performance Report

    DTIC Science & Technology

    2006-09-01

    capability to transform the surrogate compound (e.g., isobutene ) and both cis-DCE and trans-1,2-dichloroethene (trans-DCE). Isobutene was transformed...to isobutene oxide, indicating transformation by a toluene ortho- monooxygenase, and both cis-DCE and trans-DCE were added to the injected fluid and...were transformed at similar rates. Similar rates of toluene utilization, cis-DCE, and isobutene transformation were achieved using the push-pull

  10. Brownian Motion Effects on Particle Pushing and Engulfment During Solidification in Metal-Matrix Composites

    NASA Astrophysics Data System (ADS)

    Ferguson, J. B.; Kaptay, George; Schultz, Benjamin F.; Rohatgi, Pradeep K.; Cho, Kyu; Kim, Chang-Soo

    2014-09-01

    Particle pushing and/or engulfment by the moving solidification front (SF) is important for the uniform distribution of reinforcement particles in metal-matrix composites (MMCs) synthesized from solidification processing, which can lead to a substantial increase in the strength of the composite materials. Previous theoretical models describing the interactions between particle and moving SF predict that large particles will be engulfed by SF while smaller particles including nanoparticles (NPs) will be pushed by it. However, there is evidence from metal-matrix nanocomposites (MMNCs) that NPs can sometimes be engulfed and distributed throughout the material rather than pushed and concentrated in the last regions to solidify. To address this disparity, in this work, an analytical model has been developed to account for Brownian motion effects. Computer simulations employing this model over a range of the SF geometries and time steps demonstrate that NPs are often engulfed rather than pushed. Based on our results, two distinct capture mechanisms were identified: (i) when a high random velocity is imparted to the particle by Brownian motion, large jumps allow the particle to overcome the repulsion of the SF, and (ii) when the net force acting on the particle is insufficient, the particle is not accelerated to a velocity high enough to outrun the advancing SF. This manuscript will quantitatively show the effect of particle size on the steady state or critical velocity of the SF when Brownian motion are taken into consideration. The statistical results incorporating the effects of Brownian motion based on the Al/Al2O3 MMNC system clearly show that ultrafine particles can be captured by the moving SF, which cannot be predicted by any of classical deterministic treatments.

  11. An innovative and efficient method to control the shape of push-pull membrane deformable mirror.

    PubMed

    Polo, A; Haber, A; Pereira, S F; Verhaegen, M; Urbach, H P

    2012-12-03

    We carry out performance characterisation of a commercial push and pull deformable mirror with 48 actuators (Adaptica Srl). We present a detailed description of the system as well as a statistical approach on the identification of the mirror influence function. A new efficient control algorithm to induce the desired wavefront shape is also developed and comparison with other control algorithms present in literature has been made to prove the efficiency of the new approach.

  12. Suboptimal push-out bond strengths of calcium silicate-based sealers.

    PubMed

    Oliveira, D S; Cardoso, M L; Queiroz, T F; Silva, E J N L; Souza, E M; De-Deus, G

    2016-08-01

    To evaluate and compare the push-out bond strength of MTA Fillapex (Angelus, Londrina, Brazil) and iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada) to the dentine walls of root canals. AH Plus (Dentsply DeTrey, Konstaz, Germany) and MTA (Angelus, Londrina, Brazil) were used as reference materials. Sixty extracted human single-rooted teeth were selected. After standardized canal preparation and irrigation, the canals were dried with paper points and filled with one of four sealers: AH Plus, iRoot SP, MTA and MTA Fillapex. Roots were sectioned, and push-out tests were performed. The values of bond strength were analysed using the Kruskal-Wallis test. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05 for the analyses. All specimens had measurable adhesion to root dentine and no premature failure occurred. There were significant differences amongst materials (P = 0.000). MTA-filled specimens had higher push-out bond strength values (P = 0.000). AH Plus had significantly higher bond strength than both Fillapex and iRoot SP (P = 0.000). Both Fillapex and iRoot SP had the lowest push-out bond strength amongst all experimental groups (P = 0.000). No difference occurred between the two calcium silicate-based root canal sealers (P = 0.265). The adhesion to root dentine associated with newer calcium silicate-based sealers was compromised even when well-monitored laboratory conditions were used. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  13. Push pull microfluidics on a multi-level 3D CD.

    PubMed

    Thio, Tzer Hwai Gilbert; Ibrahim, Fatimah; Al-Faqheri, Wisam; Moebius, Jacob; Khalid, Noor Sakinah; Soin, Norhayati; Kahar, Maria Kahar Bador Abdul; Madou, Marc

    2013-08-21

    A technique known as thermo-pneumatic (TP) pumping is used to pump fluids on a microfluidic compact disc (CD) back towards the CD center against the centrifugal force that pushes liquids from the center to the perimeter of the disc. Trapped air expands in a TP air chamber during heating, and this creates positive pressure on liquids located in chambers connected to that chamber. While the TP air chamber and connecting channels are easy to fabricate in a one-level CD manufacturing technique, this approach provides only one way pumping between two chambers, is real-estate hungry and leads to unnecessary heating of liquids in close proximity to the TP chamber. In this paper, we present a novel TP push and pull pumping method which allows for pumping of liquid in any direction between two connected liquid chambers. To ensure that implementation of TP push and pull pumping also addresses the issue of space and heating challenges, a multi-level 3D CD design is developed, and localized forced convection heating, rather than infra-red (IR) is applied. On a multi-level 3D CD, the TP features are placed on a top level separate from the rest of the microfluidic processes that are implemented on a lower separate level. This approach allows for heat shielding of the microfluidic process level, and efficient usage of space on the CD for centrifugal handling of liquids. The use of localized forced convection heating, rather than infra-red (IR) or laser heating in earlier implementations allows not only for TP pumping of liquids while the CD is spinning but also makes heat insulation for TP pumping and other fluidic functions easier. To aid in future implementations of TP push and pull pumping on a multi-level 3D CD, study on CD surface heating is also presented. In this contribution, we also demonstrate an advanced application of pull pumping through the implementation of valve-less switch pumping.

  14. Force transmission through the wrist during performance of push-ups on a hyperextended and a neutral wrist.

    PubMed

    Polovinets, Olga; Wolf, Alon; Wollstein, Ronit

    2017-07-03

    Cross-sectional cohort. Push-ups are used ubiquitously to evaluate and strengthen the upper body. They are usually performed in 1 of 2 main ways: with the wrist in hyperextension and with the wrist in a neutral position. The purpose of our study was to compare the dynamic forces in the wrist during the 2 push-up styles. Fourteen volunteers performed push-ups in 2 different patterns: on a hyperextended wrist and a neutral wrist (NW). Two force plates and a motion capture system were used to measure the ground reaction forces (GRFs) and the kinematics of the upper extremity during push-ups. Kinematic and kinetic analyses were performed using Matlab software (Mathworks, Natick, MA). The GRF vector was distributed differently during the different types of push-ups. For both methods, the total GRF carried by the upper dominant extremity was larger than those of the nondominant extremity. In the NW configuration, the GRF vector was more uniform throughout the push-up in the vertical direction. The horizontal distance between the capitate bone location and the GRF origin was smaller in hyperextension. The forces traveled more dorsally over a wider area and more ulnarly in the hyperextended wrist. Forces are transmitted differently through the wrist in the 2 methods. Push-ups on an NW are likely safer because ligaments may be preferentially loaded in hyperextension. Further study may delineate the differences in the anatomic location of force transmission and the long-term clinical effect on the wrist. This study supports the performance of push-ups on a wrist in neutral flexion extension; both to enable patients after surgery or injury to strengthen the upper body and prevent injury and long-term wear in the wrist. The knowledge gained from this study may assist in outlining guidelines for push-up performance. Diagnostic level 2a. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  15. Modular, security enclosure and method of assembly

    DOEpatents

    Linker, Kevin L.; Moyer, John W.

    1995-01-01

    A transportable, reusable rapidly assembled and disassembled, resizable modular, security enclosure utilizes a stepped panel construction. Each panel has an inner portion and an outer portion which form joints. A plurality of channels can be affixed to selected joints of the panels. Panels can be affixed to a base member and then affixed to one another by the use of elongated pins extending through the channel joints. Alternatively, the base member can be omitted and the panels themselves can be used as the floor of the enclosure. The pins will extend generally parallel to the joint in which they are located. These elongated pins are readily inserted into and removable from the channels in a predetermined sequence to allow assembly and disassembly of the enclosure. A door constructed from panels is used to close the opening to the enclosure.

  16. SOLID GAS SUSPENSION NUCLEAR FUEL ASSEMBLY

    DOEpatents

    Schluderberg, D.C.; Ryon, J.W.

    1962-05-01

    A fuel assembly is designed for use in a gas-suspension cooled nuclear fuel reactor. The coolant fluid is an inert gas such as nitrogen or helium with particles such as carbon suspended therein. The fuel assembly is contained within an elongated pressure vessel extending down into the reactor. The fuel portion is at the lower end of the vessel and is constructed of cylindrical segments through which the coolant passes. Turbulence promotors within the passageways maintain the particles in agitation to increase its ability to transfer heat away from the outer walls. Shielding sections and alternating passageways above the fueled portion limit the escape of radiation out of the top of the vessel. (AEC)

  17. Alternative Fuel Guidelines for Alternative Transportation Systems.

    DOT National Transportation Integrated Search

    2011-01-31

    The Volpe Center documented the increased use of alternative fuels on vehicles owned and operated by federal land management agencies. For each alternative fuel type, the Volpe Center documented the availability of vehicles, fueling mechanisms and pr...

  18. Method for quantifying image quality in push-broom hyperspectral cameras

    NASA Astrophysics Data System (ADS)

    Høye, Gudrun; Løke, Trond; Fridman, Andrei

    2015-05-01

    We propose a method for measuring and quantifying image quality in push-broom hyperspectral cameras in terms of spatial misregistration caused by keystone and variations in the point spread function (PSF) across spectral channels, and image sharpness. The method is suitable for both traditional push-broom hyperspectral cameras where keystone is corrected in hardware and cameras where keystone is corrected in postprocessing, such as resampling and mixel cameras. We show how the measured camera performance can be presented graphically in an intuitive and easy to understand way, comprising both image sharpness and spatial misregistration in the same figure. For the misregistration, we suggest that both the mean standard deviation and the maximum value for each pixel are shown. We also suggest how the method could be expanded to quantify spectral misregistration caused by the smile effect and corresponding PSF variations. Finally, we have measured the performance of two HySpex SWIR 384 cameras using the suggested method. The method appears well suited for assessing camera quality and for comparing the performance of different hyperspectral imagers and could become the future standard for how to measure and quantify the image quality of push-broom hyperspectral cameras.

  19. Aerodynamic characteristics and design guidelines of push-pull ventilation systems.

    PubMed

    Huang, R F; Lin, S Y; Jan, S-Y; Hsieh, R H; Chen, Y-K; Chen, C-W; Yeh, W-Y; Chang, C-P; Shih, T-S; Chen, C-C

    2005-01-01

    Aerodynamic characteristics such as the flow patterns, velocity field, streamline evolutions, characteristic flow modes and characteristic flow regimes of the push-pull ventilation system are cross-examined by using the laser-light sheet smoked-flow visualization method and laser Doppler velocimetry. Four characteristic flow modes, which are denoted as dispersion, transition, encapsulation and strong suction, are identified in the domain of the push-jet and pull-flow velocities at various open-surface tank widths and rising gas velocities. It is argued phenomenologically, from the aerodynamic point of view, that operating the system in the strong suction regime would be a better strategy than operating it in other characteristic regimes for the consideration of capture efficiency. Design guidelines are developed and summarized based on the results obtained from this study. The regression formulas for calculating the critical values of the push-jet and the pull-flow velocities are provided for easy access. The sulfur hexafluoride tracer gas validation technique is performed to measure the capture efficiency. The results of tracer gas validations are consistent with those obtained from the aerodynamic visualization and measurements. The operation points obtained by employing the American Conference of Governmental Industrial Hygienists design criteria are compared with the results obtained in this study for both the aerodynamics and the capture efficiency. Methods for improving the capture efficiency and energy consumptions are suggested.

  20. Branched actin networks push against each other at adherens junctions to maintain cell-cell adhesion.

    PubMed

    Efimova, Nadia; Svitkina, Tatyana M

    2018-03-05

    Adherens junctions (AJs) are mechanosensitive cadherin-based intercellular adhesions that interact with the actin cytoskeleton and carry most of the mechanical load at cell-cell junctions. Both Arp2/3 complex-dependent actin polymerization generating pushing force and nonmuscle myosin II (NMII)-dependent contraction producing pulling force are necessary for AJ morphogenesis. Which actin system directly interacts with AJs is unknown. Using platinum replica electron microscopy of endothelial cells, we show that vascular endothelial (VE)-cadherin colocalizes with Arp2/3 complex-positive actin networks at different AJ types and is positioned at the interface between two oppositely oriented branched networks from adjacent cells. In contrast, actin-NMII bundles are located more distally from the VE-cadherin-rich zone. After Arp2/3 complex inhibition, linear AJs split, leaving gaps between cells with detergent-insoluble VE-cadherin transiently associated with the gap edges. After NMII inhibition, VE-cadherin is lost from gap edges. We propose that the actin cytoskeleton at AJs acts as a dynamic push-pull system, wherein pushing forces maintain extracellular VE-cadherin transinteraction and pulling forces stabilize intracellular adhesion complexes. © 2018 Efimova and Svitkina.

  1. Analysis of Stress in Steel and Concrete in Cfst Push-Out Test Samples

    NASA Astrophysics Data System (ADS)

    Grzeszykowski, Bartosz; Szadkowska, Magdalena; Szmigiera, Elżbieta

    2017-09-01

    The paper presents the analysis of stress in steel and concrete in CFST composite elements subjected to push-out tests. Two analytical models of stress distribution are presented. The bond at the interface between steel and concrete in the initial phase of the push-out test is provided by the adhesion. Until the force reach a certain value, the slip between both materials does not occur or it is negligibly small, what ensures full composite action of the specimen. In the first analytical model the full bond between both materials was assumed. This model allows to estimate value of the force for which the local loss of adhesion in given cross section begins. In the second model it was assumed that the bond stress distribution is constant along the shear transfer length of the specimen. Based on that the formulas for triangle distribution of stress in steel and concrete for the maximum push-out force were derived and compared with the experimental results. Both models can be used to better understand the mechanisms of interaction between steel and concrete in composite steel-concrete columns.

  2. Individual muscle contributions to push and recovery subtasks during wheelchair propulsion.

    PubMed

    Rankin, Jeffery W; Richter, W Mark; Neptune, Richard R

    2011-04-29

    Manual wheelchair propulsion places considerable physical demand on the upper extremity and is one of the primary activities associated with the high prevalence of upper extremity overuse injuries and pain among wheelchair users. As a result, recent effort has focused on determining how various propulsion techniques influence upper extremity demand during wheelchair propulsion. However, an important prerequisite for identifying the relationships between propulsion techniques and upper extremity demand is to understand how individual muscles contribute to the mechanical energetics of wheelchair propulsion. The purpose of this study was to use a forward dynamics simulation of wheelchair propulsion to quantify how individual muscles deliver, absorb and/or transfer mechanical power during propulsion. The analysis showed that muscles contribute to either push (i.e., deliver mechanical power to the handrim) or recovery (i.e., reposition the arm) subtasks, with the shoulder flexors being the primary contributors to the push and the shoulder extensors being the primary contributors to the recovery. In addition, significant activity from the shoulder muscles was required during the transition between push and recovery, which resulted in increased co-contraction and upper extremity demand. Thus, strengthening the shoulder flexors and promoting propulsion techniques that improve transition mechanics have much potential to reduce upper extremity demand and improve rehabilitation outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Field Evaluation of a Push-Pull System to Reduce Malaria Transmission

    PubMed Central

    Menger, David J.; Omusula, Philemon; Holdinga, Maarten; Homan, Tobias; Carreira, Ana S.; Vandendaele, Patrice; Derycke, Jean-Luc; Mweresa, Collins K.; Mukabana, Wolfgang Richard; van Loon, Joop J. A.; Takken, Willem

    2015-01-01

    Malaria continues to place a disease burden on millions of people throughout the tropics, especially in sub-Saharan Africa. Although efforts to control mosquito populations and reduce human-vector contact, such as long-lasting insecticidal nets and indoor residual spraying, have led to significant decreases in malaria incidence, further progress is now threatened by the widespread development of physiological and behavioural insecticide-resistance as well as changes in the composition of vector populations. A mosquito-directed push-pull system based on the simultaneous use of attractive and repellent volatiles offers a complementary tool to existing vector-control methods. In this study, the combination of a trap baited with a five-compound attractant and a strip of net-fabric impregnated with micro-encapsulated repellent and placed in the eaves of houses, was tested in a malaria-endemic village in western Kenya. Using the repellent delta-undecalactone, mosquito house entry was reduced by more than 50%, while the traps caught high numbers of outdoor flying mosquitoes. Model simulations predict that, assuming area-wide coverage, the addition of such a push-pull system to existing prevention efforts will result in up to 20-fold reductions in the entomological inoculation rate. Reductions of such magnitude are also predicted when mosquitoes exhibit a high resistance against insecticides. We conclude that a push-pull system based on non-toxic volatiles provides an important addition to existing strategies for malaria prevention. PMID:25923114

  4. Pushing Gravity in a Static Universe with a Compton Effect Red Shift

    NASA Astrophysics Data System (ADS)

    Kierein, John

    2004-05-01

    Pushing gravity has a long history (M. Edwards, Pushing Gravity, New Perspectives on Le Sage's Theory of Gravitation, Apeiron, Montreal, 2002). The Compton effect interpretation of the red shift results in a static universe with an excess of very long wavelength, highly penetrating background radiation. The problem of the stability of a static universe (R. Tolman, Relativity, Thermodynamics and Cosmology, pp 361-407, Oxford U. Press, Oxford, U.K. 1934) is solved by a pushing gravity due to this radiation in accordance with the Brush theory (C.F. Brush, Nature 86, 130, 1911 and Science 33, 381, 1911). Reber's measurements of the unexpectedly bright background at 144 meters and 500 meters are the shorter end of this gravitation-causing radiation. The graviton in this model is the quantization of the "shadow" cast by a mass similar to a hole in semiconductor theory. Short wavelength versions of this theory ("mock gravity") have been invoked to explain galaxy formation (C.J. Hogan and S.D.M. White, Nature 321, 575, 1986) and planetary formation (L. Spitzer, Astrophysical J. 94, 232, 1941 and F. Whipple, Astrophysical J. 104, 1, 1946).

  5. Glass-plastic push-pull cannula system for regional perfusion of sites in the brain.

    PubMed

    Myers, R D; Hepler, J R

    1983-10-01

    A new non-metallic push-pull cannula device is described for the localized perfusion of brain sites in the rat or other animal. Comprised entirely of glass and plastic materials, the cannula is intended for usage in an experiment in which the presence in tissue of metal tubing for delivery of perfusate is methodologically inappropriate. The main features of the cannula include its light weight, a Delrin pedestal base, a micro-glass guide tube, a polyethylene stylet, plastic spacers for adjustment of depth of perfusion, a protective cap for the chronic maintenance of the preparation, low cost and re-usability. The push-pull cannula is of concentric design and is fashioned from glass capillary and polyethylene tubing which are bonded at their common junctions by an epoxy cement. During a push-pull perfusion a special perfusion cap is used not only to hold the cannula firmly in place but also to protect the glass components from external damage. To further coincide with the metal-free requirements of the preparation, bone screws of nylon are used during the surgical implantation of the pedestal base. A prototype experiment illustrating its use in an unrestrained animal also is presented. The special applications for this cannula system are discussed which include its usage in experiments in either the anesthetized or unanesthetized rat exposed to microwave radiation where the presence of metal in the field would result in unwanted 'hot spots' in the cerebral tissue.

  6. Individual Muscle Contributions to Push and Recovery Subtasks during Wheelchair Propulsion

    PubMed Central

    Rankin, Jeffery W.; Richter, W. Mark; Neptune, Richard R.

    2011-01-01

    Manual wheelchair propulsion places considerable physical demand on the upper extremity and is one of the primary activities associated with the high prevalence of upper extremity overuse injuries and pain among wheelchair users. As a result, recent effort has focused on determining how various propulsion techniques influence upper extremity demand during wheelchair propulsion. However, an important prerequisite for identifying the relationships between propulsion techniques and upper extremity demand is to understand how individual muscles contribute to the mechanical energetics of wheelchair propulsion. Therefore, the purpose of this study was to use a forward dynamics simulation of wheelchair propulsion to quantify how individual muscles deliver, absorb and/or transfer mechanical power during propulsion. The analysis showed that muscles contribute to either push (i.e. deliver mechanical power to the handrim) or recovery (i.e. reposition the arm) subtasks, with the shoulder flexors being the primary contributors to the push and the shoulder extensors being the primary contributors to the recovery. In addition, significant activity from the shoulder muscles was required during the transition between push and recovery, which resulted in increased co-contraction and upper extremity demand. Thus, strengthening the shoulder flexors and promoting propulsion techniques that improve transition mechanics have much potential to reduce upper extremity demand and improve rehabilitation outcomes. PMID:21397232

  7. Common-pull, multiple-push, vacuum-activated telescope mirror cell.

    PubMed

    Ruiz, Elfego; Sohn, Erika; Salas, Luis; Luna, Esteban; Araiza-Durán, José A

    2014-11-20

    A new concept for push-pull active optics is presented, where the push-force is provided by means of individual airbag type actuators and a common force in the form of a vacuum is applied to the entire back of the mirror. The vacuum provides the pull-component of the system, in addition to gravity. Vacuum is controlled as a function of the zenithal angle, providing correction for the axial component of the mirror's weight. In this way, the push actuators are only responsible for correcting mirror deformations, as well as for supporting the axial mirror weight at the zenith, allowing for a uniform, full dynamic-range behavior of the system along the telescope's pointing range. This can result in the ability to perform corrections of up to a few microns for low-order aberrations. This mirror support concept was simulated using a finite element model and was tested experimentally at the 2.12 m San Pedro Mártir telescope. Advantages such as stress-free attachments, lighter weight, large actuator area, lower system complexity, and lower required mirror-cell stiffness could make this a method to consider for future large telescopes.

  8. Space assembly fixtures and aids

    NASA Technical Reports Server (NTRS)

    Bloom, K. A.; Lillenas, A. N.

    1980-01-01

    Concepts and requirements for assembly fixtures and aids necessary for the assembly and maintenance of spare platforms were studied. Emphasis was placed on erectable and deployable type structures with the shuttle orbiter as the assembly base. Both single and multiple orbiter flight cases for the platform assembly were considered. Applicable space platform assembly studies were reviewed to provide a data base for establishing the assembly fixture and aids design requirements, assembly constraints, and the development of representative design concepts. Conclusions indicated that fixture requirements will vary with platform size. Larger platforms will require translation relative to the orbiter RMS working volume. The installation of platform payloads and subsystems (e.g., utility distribution) must also be considered in the specification of assembly fixtures and aids.

  9. Self-assembly: Misfits unite

    NASA Astrophysics Data System (ADS)

    Grason, Gregory M.

    2017-12-01

    The spontaneous assembly of particulate or molecular 'building blocks' into larger architectures underlies structure formation in many biological and synthetic materials. Shape frustration of ill-fitting blocks holds a surprising key to more regular assemblies.

  10. Protein directed assembly of lipids.

    PubMed

    Nordin, Darman; Yarkoni, Orr; Donlon, Lynn; Savinykh, Natalia; Frankel, Daniel

    2012-01-18

    Highly ordered ring-like structures are formed via the directed assembly of lipid domains in supported bilayers, using the extracellular matrix protein fibronectin. The ability of biological molecules to guide nanoscale assembly suggests potential biomimetic approaches to nanoscale structures.

  11. 40 CFR 63.7293 - What work practice standards must I meet for fugitive pushing emissions if I have a non-recovery...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... meet for fugitive pushing emissions if I have a non-recovery coke oven battery? 63.7293 Section 63.7293... Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Emission... pushing emissions if I have a non-recovery coke oven battery? (a) You must meet the requirements in...

  12. 40 CFR 63.7291 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? (a...

  13. 40 CFR 63.7293 - What work practice standards must I meet for fugitive pushing emissions if I have a non-recovery...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... meet for fugitive pushing emissions if I have a non-recovery coke oven battery? 63.7293 Section 63.7293... Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Emission... pushing emissions if I have a non-recovery coke oven battery? (a) You must meet the requirements in...

  14. 40 CFR 63.7291 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? (a...

  15. 40 CFR 63.7291 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? (a...

  16. 40 CFR 63.7293 - What work practice standards must I meet for fugitive pushing emissions if I have a non-recovery...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... meet for fugitive pushing emissions if I have a non-recovery coke oven battery? 63.7293 Section 63.7293... Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Emission... pushing emissions if I have a non-recovery coke oven battery? (a) You must meet the requirements in...

  17. 40 CFR 63.7292 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with horizontal flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with horizontal flues? (a...

  18. 40 CFR 63.7293 - What work practice standards must I meet for fugitive pushing emissions if I have a non-recovery...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... meet for fugitive pushing emissions if I have a non-recovery coke oven battery? 63.7293 Section 63.7293... Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Emission... pushing emissions if I have a non-recovery coke oven battery? (a) You must meet the requirements in...

  19. 40 CFR 63.7291 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? (a...

  20. 40 CFR 63.7293 - What work practice standards must I meet for fugitive pushing emissions if I have a non-recovery...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meet for fugitive pushing emissions if I have a non-recovery coke oven battery? 63.7293 Section 63.7293... Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks Emission... pushing emissions if I have a non-recovery coke oven battery? (a) You must meet the requirements in...

  1. 40 CFR 63.7291 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with vertical flues? (a...

  2. 40 CFR 63.7292 - What work practice standards must I meet for fugitive pushing emissions if I have a by-product...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... meet for fugitive pushing emissions if I have a by-product coke oven battery with horizontal flues? 63...) National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery... meet for fugitive pushing emissions if I have a by-product coke oven battery with horizontal flues? (a...

  3. Dielectrophoretic assembly of metallodielectric Janus particles in AC electric fields.

    PubMed

    Gangwal, Sumit; Cayre, Olivier J; Velev, Orlin D

    2008-12-02

    "Janus" particles with two hemispheres of different polarizability or charge demonstrate a multitude of interesting effects in external electric fields. We reported earlier how particles with one metallic hemisphere and one dielectric hemisphere self-propel in low-frequency alternating current (AC) electric fields. Here, we demonstrate the assembly of such Janus particles driven by AC electric fields at frequencies above 10 kHz. We investigated the relation between field-induced dielectrophoretic force, field distribution, and structure of the assemblies. The phase space for electric field intensity and frequency was explored for particle concentrations large enough to form a monolayer on a glass surface between two gold electrodes. A rich variety of metallodielectric particle structures and dynamics were uncovered, which are very different from those obtained from directed assembly of plain dielectric or plain conductive particles under the action of fields of similar frequency and intensity. The metallodielectric particles assemble into new types of chain structures, where the metallized halves of neighboring particles align into lanes along the direction of the electric field, while the dielectric halves face in alternating direction. The staggered chains may assemble in various orientations to form different types of two-dimensional metallodielectric crystals. The experimental results on the formation of staggered chains are interpreted by means of numerical simulations of the electric energy of the system. The assembly of Janus metallodielectric particles may find applications in liquid-borne microcircuits and materials with directional electric and heat transfer.

  4. Pushing the Performance Limit of Sub-100 nm Molybdenum Disulfide Transistors.

    PubMed

    Liu, Yuan; Guo, Jian; Wu, Yecun; Zhu, Enbo; Weiss, Nathan O; He, Qiyuan; Wu, Hao; Cheng, Hung-Chieh; Xu, Yang; Shakir, Imran; Huang, Yu; Duan, Xiangfeng

    2016-10-12

    Two-dimensional semiconductors (2DSCs) such as molybdenum disulfide (MoS 2 ) have attracted intense interest as an alternative electronic material in the postsilicon era. However, the ON-current density achieved in 2DSC transistors to date is considerably lower than that of silicon devices, and it remains an open question whether 2DSC transistors can offer competitive performance. A high current device requires simultaneous minimization of the contact resistance and channel length, which is a nontrivial challenge for atomically thin 2DSCs, since the typical low contact resistance approaches for 2DSCs either degrade the electronic properties of the channel or are incompatible with the fabrication process for short channel devices. Here, we report a new approach toward high-performance MoS 2 transistors by using a physically assembled nanowire as a lift-off mask to create ultrashort channel devices with pristine MoS 2 channel and self-aligned low resistance metal/graphene hybrid contact. With the optimized contact in short channel devices, we demonstrate sub-100 nm MoS 2 transistor delivering a record high ON-current of 0.83 mA/μm at 300 K and 1.48 mA/μm at 20 K, which compares well with that of silicon devices. Our study, for the first time, demonstrates that the 2DSC transistors can offer comparable performance to the 2017 target for silicon transistors in International Technology Roadmap for Semiconductors (ITRS), marking an important milestone in 2DSC electronics.

  5. Fuel nozzle assembly

    DOEpatents

    Johnson, Thomas Edward [Greer, SC; Ziminsky, Willy Steve [Simpsonville, SC; Lacey, Benjamin Paul [Greer, SC; York, William David [Greer, SC; Stevenson, Christian Xavier [Inman, SC

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  6. Solution deposition assembly

    DOEpatents

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  7. Hearing Aid Assembly

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N. (Inventor)

    2002-01-01

    Progress in hearing aids has come a long way. Yet despite such progress hearing aids are not the perfect answer to many hearing problems. Some adult ears cannot accommodate tightly fitting hearing aids. Mouth movements such as chewing, talking, and athletic or other active endeavors also lead to loosely fitting ear molds. It is well accepted that loosely fitting hearing aids are the cause of feedback noise. Since feedback noise is the most common complaint of hearing aid wearers it has been the subject of various patents. Herein a hearing aid assembly is provided eliminating feedback noise. The assembly includes the combination of a hearing aid with a headset developed to constrict feedback noise.

  8. FLUORINE CELL ANODE ASSEMBLY

    DOEpatents

    Cable, R.E.; Goode, W.B. Jr.; Henderson, W.K.; Montillon, G.H.

    1962-06-26

    An improved anode assembly is deslgned for use in electrolytlc cells ln the productlon of hydrogen and fluorlne from a moIten electrolyte. The anode assembly comprises a copper post, a copper hanger supported by the post, a plurality of carbon anode members, and bolt means for clamplng half of the anode members to one slde of the hanger and for clamplng the other half of the anode members to the other slde of the hanger. The heads of the clamplng bolts are recessed withln the anode members and carbon plugs are inserted ln the recesses above the bolt heads to protect the boIts agalnst corroslon. A copper washer is provided under the head of each clamplng boIt such that the anode members can be tightly clamped to the hanger with a resultant low anode jolnt resistance. (AEC)

  9. Turbine seal assembly

    DOEpatents

    Little, David A.

    2013-04-16

    A seal assembly that limits gas leakage from a hot gas path to one or more disc cavities in a turbine engine. The seal assembly includes a seal apparatus that limits gas leakage from the hot gas path to a respective one of the disc cavities. The seal apparatus comprises a plurality of blade members rotatable with a blade structure. The blade members are associated with the blade structure and extend toward adjacent stationary components. Each blade member includes a leading edge and a trailing edge, the leading edge of each blade member being located circumferentially in front of the blade member's corresponding trailing edge in a direction of rotation of the turbine rotor. The blade members are arranged such that a space having a component in a circumferential direction is defined between adjacent circumferentially spaced blade members.

  10. Ingestion resistant seal assembly

    DOEpatents

    Little, David A [Chuluota, FL

    2011-12-13

    A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.

  11. Vacuum breaker valve assembly

    DOEpatents

    Thompson, Jeffrey L.; Upton, Hubert Allen

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  12. Blade retainer assembly

    NASA Technical Reports Server (NTRS)

    Luebering, G. W. (Inventor)

    1977-01-01

    A retaining assembly is provided for locking radially extending blades in a rotor disc associated with a gas turbine engine. The assembly includes a pair of spaced apart lugs axially extending from one side of the disc to form an access gap for insertion of a blade tang into a dovetail slot in the rotor disc. A pair of axially aligned inwardly facing recesses are disposed in the lugs. A retaining member resides in the recesses and extends across the gap to preclude egress of the blade tang from the dovetail slot. The retaining member includes at least one axially extending protrusion adapted to radially overlap and abuttingly engage a radially inwardly facing abutment surface on the lugs.

  13. Infrared floodlight assembly

    DOEpatents

    Wierzbicki, Julian J.; Chakrabarti, Kirti B.

    1987-09-22

    An infrared floodlight assembly (10) including a cast aluminum outer housing (11) defining a central chamber (15) therein. A floodlight (14), having a tungsten halogen lamp as the light source, is spacedly positioned within a heat conducting member (43) within chamber (15) such that the floodlight is securedly positioned in an aligned manner relative to the assembly's filter (35) and lens (12) components. The invention also includes venting means (51) to allow air passage between the interior of the member (43) and the adjacent chamber (15), as well as engagement means (85) for engaging a rear surface of the floodlight (14) to retain it firmly against an internal flange of the member (43). A reflector (61), capable of being compressed to allow insertion or removal, is located within the heat conducting member's interior between the floodlight (14) and filter (35) to reflect infrared radiation toward the filter (35) and spaced lens (12).

  14. Vacuum breaker valve assembly

    DOEpatents

    Thompson, J.L.; Upton, H.A.

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

  15. Ignition system monitoring assembly

    DOEpatents

    Brushwood, John Samuel

    2003-11-04

    An ignition system monitoring assembly for use in a combustion engine is disclosed. The assembly includes an igniter having at least one positioning guide with at least one transmittal member being maintained in a preferred orientation by one of the positioning guides. The transmittal member is in optical communication with a corresponding target region, and optical information about the target region is conveyed to the reception member via the transmittal member. The device allows real-time observation of optical characteristics of the target region. The target region may be the spark gap between the igniter electrodes, or other predetermined locations in optical communication with the transmittal member. The reception member may send an output signal to a processing member which, in turn, may produce a response to the output signal.

  16. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  17. Cyclic Fiber Push-In Test Monitors Evolution of Interfacial Behavior in Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.

    1998-01-01

    SiC fiber-reinforced ceramic matrix composites are being developed for high-temperature advanced jet engine applications. Obtaining a strong, tough composite material depends critically on optimizing the mechanical coupling between the reinforcing fibers and the surrounding matrix material. This has usually been accomplished by applying a thin C or BN coating onto the surface of the reinforcing fibers. The performance of these fiber coatings, however, may degrade under cyclic loading conditions or exposure to different environments. Degradation of the coating-controlled interfacial behavior will strongly affect the useful service lifetime of the composite material. Cyclic fiber push-in testing was applied to monitor the evolution of fiber sliding behavior in both C- and BN-coated small-diameter (15-mm) SiC-fiber-reinforced ceramic matrix composites. The cyclic fiber push-in tests were performed using a desktop fiber push-out apparatus. At the beginning of each test, the fiber to be tested was aligned underneath a 10- mm-diameter diamond punch; then, the applied load was cycled between selected maximum and minimum loads. From the measured response, the fiber sliding distance and frictional sliding stresses were determined for each cycle. Tests were performed in both room air and nitrogen. Cyclic fiber push-in tests of C-coated, SiC-fiber-reinforced SiC showed progressive increases in fiber sliding distances along with decreases in frictional sliding stresses for continued cycling in room air. This rapid degradation in interfacial response was not observed for cycling in nitrogen, indicating that moisture exposure had a large effect in immediately lowering the frictional sliding stresses of C-coated fibers. These results indicate that matrix cracks bridged by C-coated fibers will not be stable, but will rapidly grow in moisture-containing environments. In contrast, cyclic fiber push-in tests of both BN-coated, SiC-fiber-reinforced SiC and BNcoated, Si

  18. REACTOR NOZZLE ASSEMBLY

    DOEpatents

    Capuder, F.C.; Dearwater, J.R.

    1959-02-10

    An improved nozzle assembly useful in a process for the direct reduction of uranium hexafluoride to uranium tetrafluoride by means of dissociated ammonia in a heated reaction vessel is descrlbed. The nozzle design provides for intimate mixing of the two reactants and at the same time furnishes a layer of dissociated ammonia adjacent to the interior wall of the reaction vessel, thus preventing build-up of the reaction product on the vessel wall.

  19. Pull rod assembly

    DOEpatents

    Cioletti, O.C.

    1988-04-21

    A pull rod assembly comprising a pull rod having three peripheral grooves, a piston device including an adaptor ring and a seal ring, said piston device being mounted on the pull rod by a split ring retainer situated in one groove and extending into an interior groove in the adaptor and a resilient split ring retained in another groove and positioned to engage the piston device and to retain the seal on its adaptor.

  20. Composite airfoil assembly

    SciTech Connect

    Garcia-Crespo, Andres Jose

    2015-03-03

    A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.