WorldWideScience

Sample records for push pull trains

  1. PushPull++

    KAUST Repository

    Lipp, Markus

    2014-07-22

    PushPull tools are implemented in most commercial 3D modeling suites. Their purpose is to intuitively transform a face, edge, or vertex, and then to adapt the polygonal mesh locally. However, previous approaches have limitations: Some allow adjustments only when adjacent faces are orthogonal; others support slanted surfaces but never create new details. Moreover, self-intersections and edge-collapses during editing are either ignored or work only partially for solid geometry. To overcome these limitations, we introduce the PushPull++ tool for rapid polygonal modeling. In our solution, we contribute novel methods for adaptive face insertion, adjacent face updates, edge collapse handling, and an intuitive user interface that automatically proposes useful drag directions. We show that PushPull++ reduces the complexity of common modeling tasks by up to an order of magnitude when compared with existing tools. Copyright © ACM.

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

    Science.gov (United States)

    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. Foot placement strategy in pushing and pulling.

    Science.gov (United States)

    Lee, Tzu-Hsien

    2018-01-01

    Pushing and pulling tasks are very common in daily and industrial workplaces. They are one major source of musculoskeletal complaints. This study aimed to examine the foot placement strategy while pushing and pulling. Thirteen young males and ten young females were recruited as participants. A two (pushing and pulling) by four (48 cm, 84 cm, 120 cm, and 156 cm) factorial design was used. Exertion direction and exertion height significantly affected foot placement strategy. Pushing task needed more anteroposterior space than pulling task. The percentages of female/male for trailing foot position ranged from 77% to 90% (pushing) and from 80% to 93% (pulling) across the exertion heights. Practitioners should provide an anteroposterior space approximately to 70% body stature for workers to exert their maximum pulling and pushing strengths.

  4. PushPull++

    KAUST Repository

    Lipp, Markus; Wonka, Peter; Mü ller, Pascal

    2014-01-01

    PushPull tools are implemented in most commercial 3D modeling suites. Their purpose is to intuitively transform a face, edge, or vertex, and then to adapt the polygonal mesh locally. However, previous approaches have limitations: Some allow

  5. Import-push or Export-pull?

    DEFF Research Database (Denmark)

    Jäkel, Ina Charlotte

    2014-01-01

    predictions regarding the export market and the role of product differentiation. Empirical results for a sample of Danish manufacturing industries confirm the import- "push" hypothesis as well as the export- "pull" hypothesis, but also reveal differences across industries. The selection effect of trade...... is mainly driven by the "import-push" if product differentiation is high, whereas it is driven by the "export-pull" if goods are homogeneous....

  6. Import-push or Export-pull?

    DEFF Research Database (Denmark)

    Jäkel, Ina Charlotte

    predictions regarding the export market and the role of product differentiation. Empirical results for a sample of Danish manufacturing industries confirm the import-"push" hypothesis as well as the export-"pull" hypothesis, but also reveal differences across industries. The selection effect of trade...... is mainly driven by the "import-push" if product differentiation is high, whereas it is driven by the "export-pull" if goods are homogeneous....

  7. Young entrepreneurs pushed by necessity and pulled by opportunity

    DEFF Research Database (Denmark)

    Cheraghi, Maryam

    2017-01-01

    The vocational choice to be an entrepreneur is made in a social context of institutions in society, which channel, regulate, enable and constrain life, with pushes and pulls. The necessity to make a living may push the entrepreneur, or an opportunity for business may pull the entrepreneur to start....... The push by necessity and pull by opportunity are exerted by institutions in society such as its economy and culture. The purpose here is to account for how young entrepreneurs' experiences of opportunity-pull and necessity-push are influenced by society's economic wealth and culture, as traditional versus...... secular-rational culture and as survival versus self-expression culture. - A sample of 41,281 young entrepreneurs in 93 countries was surveyed in Global Entrepreneurship Monitor. - Analyses show that young entrepreneurs' experience of opportunity-pull rather than necessity-push is not distinctly...

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

    Science.gov (United States)

    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.

  9. Push-pull quinoidal porphyrins.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-03-01

    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.

  11. Pushing and pulling in relation to musculoskeletal complaints

    NARCIS (Netherlands)

    Hoozemans, M. J M; Van Der Beek, Allard J.; Frings-Dresen, M. H. W.

    2000-01-01

    The first cross-sectional analyses are presented of a longitudinal study regarding the relationship between pushing and pulling and musculoskeletal disorders. Workers exposed to pushing and pulling and workers who had administrative tasks received a questionnaire. A significant association between

  12. INTERSESSION RELIABILITY OF UPPER EXTREMITY ISOKINETIC PUSH-PULL TESTING.

    Science.gov (United States)

    Riemann, Bryan L; Davis, Sarah E; Huet, Kevin; Davies, George J

    2016-02-01

    Based on the frequency pushing and pulling patterns are used in functional activities, there is a need to establish an objective method of quantifying the muscle performance characteristics associated with these motions, particularly during the later stages of rehabilitation as criteria for discharge. While isokinetic assessment offers an approach to quantifying muscle performance, little is known about closed kinetic chain (CKC) isokinetic testing of the upper extremity (UE). To determine the intersession reliability of isokinetic upper extremity measurement of pushing and pulling peak force and average power at slow (0.24 m/s), medium (0.43 m/s) and fast (0.61 m/s) velocities in healthy young adults. The secondary purpose was to compare pushing and pulling peak force (PF) and average power (AP) between the upper extremity limbs (dominant, non-dominant) across the three velocities. Twenty-four physically active men and women completed a test-retest (>96 hours) protocol in order to establish isokinetic UE CKC reliability of PF and AP during five maximal push and pull repetitions at three velocities. Both limb and speed orders were randomized between subjects. High test-retest relative reliability using intraclass correlation coefficients (ICC2, 1) were revealed for PF (.91-.97) and AP (.85-.95) across velocities, limbs and directions. PF typical error (% coefficient of variation) ranged from 6.1% to 11.3% while AP ranged from 9.9% to 26.7%. PF decreased significantly (p pushing were significantly greater than pulling at all velocities, however the push-pull differences in PF became less as velocity increased. There were no significant differences identified between the dominant and nondominant limbs. Isokinetically derived UE CKC push-pull PF and AP are reliable measures. The lack of limb differences in healthy normal participants suggests that clinicians can consider bilateral comparisons when interpreting test performance. The increase in pushing PF and

  13. KOMPARASI SISTEM MANUFAKTUR PUSH DAN PULL MELALUI PENDEKATAN SIMULASI

    Directory of Open Access Journals (Sweden)

    Eric Wibisono

    2004-01-01

    Full Text Available Manufacturing systems that are often classified as push and pull often invite question: "How far do the differences between those two systems exist?" Many researches have been carried out but succinct answer to the above question is always difficult to reach. The difficulty roots from the variety of definition of the push and pull systems itself and also from the variety of complexity of a manufacturing system. This paper attempts to study the differences in performance between push and pull systems in a relatively simple model that consists of 4 serial processors with buffers located between these processors. Variations being modelled is on the setting of the system's load (high and low and the buffer size with performance being measured include machine utilization, number of outputs and mean flow time of jobs. The approach used is simulation using ProModel software as the tool. From the experiments it can be derived that buffer size turns out to be a very critical factor in system performance. Moreover, it is also proved that when the buffer size is large, push and pull systems do not differ significantly. Abstract in Bahasa Indonesia : Sistem manufaktur yang umumnya dikategorikan menjadi sistem push dan pull sering mengundang pertanyaan: "Seberapa jauh perbedaan dari kedua sistem tersebut ada?" Banyak penelitian telah dilakukan namun jawaban yang lugas atas pertanyaan tersebut sulit diperoleh. Kesulitan ini umumnya berakar dari beragamnya definisi sistem push dan pull itu sendiri serta variasi dari kompleksitas suatu sistem manufaktur. Makalah ini mencoba melihat perbedaan antara kinerja sistem push dan pull dalam suatu model sederhana yang terdiri dari 4 prosesor serial dengan buffer yang diletakkan di antara masing-masing prosesor tersebut. Variasi yang dilakukan adalah pada setting beban kerja sistem (padat dan ringan dan ukuran buffer dengan kinerja yang diukur adalah utilisasi mesin, jumlah output dan rata-rata waktu tinggal job

  14. Pushing, pulling and manoeuvring an industrial cart: a psychophysiological study.

    Science.gov (United States)

    Giagloglou, Evanthia; Radenkovic, Milan; Brankovic, Sasa; Antoniou, Panagiotis; Zivanovic-Macuzic, Ivana

    2017-09-18

    One of the most frequent manual occupational tasks involves the pushing and pulling of a cart. Although several studies have associated health risks with pushing and pulling, the effects are not clear since occupational tasks have social, cognitive and physical components. The present work investigates a real case of a pushing and pulling occupational task from a manufacturing company. The study initially characterizes the case in accordance with Standard No. ISO 11228-2:2007 as low risk. An experiment with 14 individuals during three modalities of pushing and pulling was performed in order to further investigate the task with the application of electrophysiology. At the end, a simple questionnaire was given. The results show electrophysiological differences among the three modalities of pushing and pulling, with a major difference between action with no load and fully loaded with a full range of motions on the cart to handle.

  15. Push-pull alkenes: structure and p-electron distribution

    Directory of Open Access Journals (Sweden)

    ERICH KLEINPETER

    2006-01-01

    Full Text Available Push-pull alkenes are substituted alkenes with one or two electron-donating substituents on one end of C=C double bond and with one or two electron-accepting substituents at the other end. Allowance for p-electron delocalization leads to the central C=C double bond becoming ever more polarized and with rising push-pull character, the p-bond order of this double bond is reduced and, conversely, the corresponding p-bond orders of the C–Don and C–Acc bonds are accordingly increased. This push-pull effect is of decisive influence on both the dynamic behavior and the chemical reactivity of this class of compounds and thus it is of considerable interest to both determine and to quantify the inherent push-pull effect. Previously, the barriers to rotation about the C=C, C–Don and/or C–Acc partial double bonds (DG±, as determined by dynamic NMR spectroscopy or the 13C chemical shift difference of the polarized C=C partial double bond (DdC=C were employed for this purpose. However, these parameters can have serious limitations, viz. the barriers can be immeasurable on the NMR timescale (either by being too high or too low; heavily-biased conformers are present, etc. or DdC=C behaves in a non-additive manner with respect to the combination of the four substituents. Hence, a general parameter to quantify the push-pull effect is not yet available. Ab initio MO calculations on a collection of compounds, together with NBO analysis, provided valuable information on the structure, bond energies, electron occupancies and bonding/antibonding interactions. In addition to DG±C=C (either experimentally determined or theoretically calculated and DdC=C, the bond length of the C=C partial double bond was also examined and it proved to be a reliable parameter to quantify the push-pull effect. Equally so, the quotient of the occupation numbers of the antibonding andbonding p orbitals of the central C=C partial double bond ( p*C=C/ pC=C could also be employed for

  16. Force direction in pushing and pulling and Musculo-Skeletal load

    NARCIS (Netherlands)

    Looze, M.P. de; Kuijer, P.P.F.M.

    1999-01-01

    In pushing and pulling wheeled objects, the effect of the exerted force on local musculo-skeletal loads depends on the direction of force exertion. Several questions about the direction of force exertion in pushing and pulling, the effects of handle height and force level on force direction, and the

  17. Technology and trend management at the interface of technology push and market pull

    DEFF Research Database (Denmark)

    Maier, Maximilian; Hofmann, Maximilian; Brem, Alexander

    2016-01-01

    Technology push and market pull innovation strategies are playing an important role for the effective management of ideas, technologies, and trends. The coexistence of these two approaches led to many debates and the focus switched several times from putting more effort into technology push aspects...... to fostering market pull approaches in the last decades. Still, there is no in-depth exploration of the interface of technology push and market pull and only few conceptual models are dealing with the connection between technology push and market pull in particular. Therefore, this study puts an exploratory...... focus on the innovation management processes of a global outdoor manufacturer with a special emphasis on the interface between technology push and market pull. From the case findings and our literature we conceptualise a non-linear innovation model that systematically integrates market pull...

  18. Using Metaheuristic and Fuzzy System for the Optimization of Material Pull in a Push-Pull Flow Logistics Network

    Directory of Open Access Journals (Sweden)

    Afshin Mehrsai

    2013-01-01

    Full Text Available Alternative material flow strategies in logistics networks have crucial influences on the overall performance of the networks. Material flows can follow push, pull, or hybrid systems. To get the advantages of both push and pull flows in networks, the decoupling-point strategy is used as coordination mean. At this point, material pull has to get optimized concerning customer orders against pushed replenishment-rates. To compensate the ambiguity and uncertainty of both dynamic flows, fuzzy set theory can practically be applied. This paper has conceptual and mathematical parts to explain the performance of the push-pull flow strategy in a supply network and to give a novel solution for optimizing the pull side employing Conwip system. Alternative numbers of pallets and their lot-sizes circulating in the assembly system are getting optimized in accordance with a multi-objective problem; employing a hybrid approach out of meta-heuristics (genetic algorithm and simulated annealing and fuzzy system. Two main fuzzy sets as triangular and trapezoidal are applied in this technique for estimating ill-defined waiting times. The configured technique leads to smoother flows between push and pull sides in complex networks. A discrete-event simulation model is developed to analyze this thesis in an exemplary logistics network with dynamics.

  19. Push-pull optical pumping of pure superposition states

    International Nuclear Information System (INIS)

    Jau, Y.-Y.; Miron, E.; Post, A.B.; Kuzma, N.N.; Happer, W.

    2004-01-01

    A new optical pumping method, 'push-pull pumping', can produce very nearly pure, coherent superposition states between the initial and the final sublevels of the important field-independent 0-0 clock resonance of alkali-metal atoms. The key requirement for push-pull pumping is the use of D1 resonant light which alternates between left and right circular polarization at the Bohr frequency of the state. The new pumping method works for a wide range of conditions, including atomic beams with almost no collisions, and atoms in buffer gases with pressures of many atmospheres

  20. 14 mrad Extraction Line Optics for Push-Pull

    International Nuclear Information System (INIS)

    Nosochkov, Y.; Moffeit, K.; Seryi, A.; Morse, W.; Parker, B.

    2007-01-01

    The ILC design is based on a single Interaction Region (IR) with 14 mrad crossing angle and two detectors in the 'push-pull' configuration, where the detectors can alternately occupy the Interaction Point (IP). Consequently, the IR optics must be compatible with different size detectors designed for different distance L* between the IP and the nearest quadrupole. This paper presents the push-pull optics for the ILC extraction line compatible with L*= 3.5 m to 4.5 m, and the simulation results of extraction beam loss at 500 GeV CM with detector solenoid

  1. Trunk response and stability in standing under sagittal-symmetric pull-push forces at different orientations, elevations and magnitudes.

    Science.gov (United States)

    El Ouaaid, Z; Shirazi-Adl, A; Plamondon, A

    2018-03-21

    To reduce lifting and associated low back injuries, manual material handling operations often involve pulling-pushing of carts at different weights, orientations, and heights. The loads on spine and risk of injury however need to be investigated. The aim of this study was to evaluate muscle forces, spinal loads and trunk stability in pull-push tasks in sagittal-symmetric, static upright standing posture. Three hand-held load magnitudes (80, 120 and 160 N) at four elevations (0, 20, 40 and 60 cm to the L5-S1) and 24 force directions covering all pull/push orientations were considered. For this purpose, a musculoskeletal finite element model with kinematics measured earlier were used. Results demonstrated that peak spinal forces occur under inclined pull (lift) at upper elevations but inclined push at the lowermost one. Minimal spinal loads, on the other hand, occurred at and around vertical pull directions. Overall, spinal forces closely followed variations in the net external moment of pull-push forces at the L5-S1. Local lumbar muscles were most active in pulls while global extensor muscles in lifts. The trunk stability margin decreased with load elevation except at and around horizontal push; it peaked under pulls and reached minimum at vertical lifts. It also increased with antagonist activity in muscles and intra-abdominal pressure. Results provide insight into the marked effects of variation in the load orientation and elevation on muscle forces, spinal loads and trunk stability and hence offer help in rehabilitation, performance enhancement training and design of safer workplaces. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  3. Positioning of microtubule organizing centers by cortical pushing and pulling forces

    International Nuclear Information System (INIS)

    Pavin, Nenad; Ma Rui; Jülicher, Frank; Laan, Liedewij; Dogterom, Marileen

    2012-01-01

    Positioning of microtubule (MT) organizing centers with respect to the confining geometry of cells depends on pushing and/or pulling forces generated by MTs that interact with the cell cortex (Dogterom et al 2005 Curr. Opin. Cell Biol. 17 67–74). How, in living cells, these forces lead to proper positioning is still largely an open question. Recently, it was shown by in vitro experiments using artificial microchambers that in a square geometry, MT asters center more reliably by a combination of pulling and pushing forces than by pushing forces alone (Laan et al 2012a Cell 148 502–14). These findings were explained by a physical description of aster mechanics that includes slipping of pushing MT ends along chamber boundaries. In this paper, we extend that theoretical work by studying the influence of the shape of the confining geometry on the positioning process. We find that pushing and pulling forces can have centering or off-centering behavior in different geometries. Pushing forces center in a one-dimensional and a square geometry, but lead to off-centering in a circle if slipping is sufficiently pronounced. Pulling forces, however, do not center in a one-dimensional geometry, but improve centering in a circle and a square. In an elongated stadium geometry, positioning along the short axis depends mainly on pulling forces, while positioning along the long axis depends mainly on pushing forces. Our theoretical results suggest that different positioning strategies could be used by different cell types. (paper)

  4. Push-Pull Ventilation in a Painting Shop for Large Steel Constructions

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per

    This paper describes the analysis of a push-pull ventilation system for a painting shop that is used for painting steel chimneys and windmill towers.......This paper describes the analysis of a push-pull ventilation system for a painting shop that is used for painting steel chimneys and windmill towers....

  5. A demonstration of NIOSH push-pull ventilation criteria.

    Science.gov (United States)

    Klein, M K

    1987-03-01

    This paper summarizes the results of a study performed on an actual chrome plating tank in order to validate criteria for push-pull ventilation systems developed by Huebener and Hughes at NIOSH. Validation of the criteria was made by taking area industrial hygiene samples for hexavalent and total chrome at ten locations around the plating tank. The sampling was performed during actual production runs or while the tank was operating with a dummy load. The sampling data are summarized. The data show that the push-pull system, operating at Huebener's criteria, could control emissions to below the current standards and guidelines. Conclusions and recommendations are included.

  6. Modelling the behaviour of the push-pull gel dosimeter

    International Nuclear Information System (INIS)

    Bosi, S.G.; Davies, J.B.; Gorjiara, T.; Baldock, C.

    2010-01-01

    Full text: Recent development of a gel dosimeter based on the radiobleaching pigment, genipin, allows development of a new 3D optically scanned gel dosimeter-the p ush-pull g el. This gel would contain two spectrally complementary pigments, one which darkens with dose and another (e.g. genipin) which bleaches. The two pigments deal separately with the high and low dose ends of the dosimeter's dynamic range. The bleaching pigment would be optimised for high sensitivity and the darkening pigment for low. Employing dual pigments, optimised independently, relaxes the need for compromise between sensitivity at low dose and accuracy at high dose. Such a gel, after exposure, would be read using two successive optical CT scans, at two different wavelengths. The reduction in sensitivity of the darkening pigment (allowed by the use of push-pull) would reduce the occurrence of regions of high optical attenuation which can generate optical CT artefacts. Simulated optical CT reconstructions of the optical density map (Fig. La) scanned at the darkening pigment wavelength of a hypothetical push-pull gel, confirms the reduction in susceptibility to artefacts. Fig. I b shows a profile through the map with no stray light added. The centre of the profile in Fig. I d shows a cupping artefact produced by 10 ppm of stray light. The similarity of Fig. Ic and b show that a 30% sensitivity reduction allowed by push-pull, renders the artefact negligible. This paper presents the results of' these simulations of a push-pull gel scanned using optical CT and also some results of experiments with genipin gel. (author)

  7. Beyond Knut Holt's fusion model, balancing market pull and technology push

    NARCIS (Netherlands)

    Nagel, A.P.

    2003-01-01

    Should a firm rely on market pull or on technology push? Some scholars have extreme opinions on this and firms do switch emphasis on push and pull over time. Knut Holt, the first president of ISPIM, presented his so-called Fusion Model in the early 1970s to shed light onto this debate. This paper

  8. Low-back and shoulder complaints among workers with pushing and pulling tasks

    NARCIS (Netherlands)

    Hoozemans, Marco J. M.; van der Beek, Allard J.; Fring-Dresen, Monique H. W.; van der Woude, Luc H. V.; van Dijk, Frank J. H.

    2002-01-01

    Objectives Low-back and shoulder complaints were examined in relation to self-reported and objectively assessed exposure to work-related pushing and pulling. Methods Workers from several companies (eg, nursing homes and flower auctions) with pushing and pulling tasks and, as reference, workers

  9. A centrifuge simulated push-pull manoeuvre with subsequent reduced +Gz tolerance.

    Science.gov (United States)

    Xu, Yan; Li, Bao-Hui; Zhang, Li-Hui; Jin, Zhao; Wei, Xiao-Yang; Wang, Hong; Wu, San-Yuan; Wang, Hai-Xia; Wang, Quan; Yan, Gui-Ding; Deng, Lue; Geng, Xi-Chen

    2012-07-01

    The push-pull effect (PPE) has been recognized as a deleterious contributor to fatal flight accidents. The purpose of the study was to establish a push-pull manoeuvre (PPM) simulation with a tri-axes centrifuge, studying the effect of this PPM on the +Gz tolerance, and to make this simulation suitable for pilot centrifuge training. The PPM was realized through pre-programmed acceleration profiles consisting of -1 Gz for 5 s followed by a +Gz plateau for 10 s. Relaxed +Gz tolerance recordings were obtained from 20 healthy male fighter aircraft pilots and 6 healthy male volunteers through exposure to pre-programmed profiles with and without previous -1 Gz exposure. A statistically significant decrease in +Gz tolerance was seen in all subjects after -1 Gz for 5 s exposure, 0.87 ± 0.13 G in the volunteer group and 0.95 ± 0.25 G in the pilot group. The ear opacity pulse as a +Gz tolerance endpoint criterion was sometimes found to be unreliable during the PPM experiments. The simulated PPM in this study elicited a PPE, which was obvious from the significant reduction in +Gz tolerance. The PPM profile appears useful to be included in centrifuge training.

  10. Pushing and pulling: an assessment tool for occupational health and safety practitioners.

    Science.gov (United States)

    Lind, Carl Mikael

    2018-03-01

    A tool has been developed for supporting practitioners when assessing manual pushing and pulling operations based on an initiative by two global companies in the manufacturing industry. The aim of the tool is to support occupational health and safety practitioners in risk assessment and risk management of pushing and pulling operations in the manufacturing and logistics industries. The tool is based on a nine-multiplier equation that includes a wide range of factors affecting an operator's health risk and capacity in pushing and pulling. These multipliers are based on psychophysical, physiological and biomechanical studies in combination with judgments from an expert group consisting of senior researchers and ergonomists. In order to consider usability, more than 50 occupational health and safety practitioners (e.g., ergonomists, managers, safety representatives and production personnel) participated in the development of the tool. An evaluation by 22 ergonomists supports that the push/pull tool is user friendly in general.

  11. Upper body push and pull strength ratio in recreationally active adults.

    Science.gov (United States)

    Negrete, Rodney J; Hanney, William J; Pabian, Patrick; Kolber, Morey J

    2013-04-01

    Agonist to antagonist strength data is commonly analyzed due to its association with injury and performance. The purpose of this study was to examine the agonist to antagonist ratio of upper body strength using two simple field tests (timed push up/timed modified pull up) in recreationally active adults and to establish the basis for reference standards. One hundred eighty (180) healthy recreationally active adults (111 females and 69 males, aged 18-45 years) performed two tests of upper body strength in random order: 1. Push-ups completed during 3 sets of 15 seconds with a 45 second rest period between each set and 2. Modified pull-ups completed during 3 sets of 15 seconds with a 45 second rest period between each set. The push-up to modified pull-up ratio for the males was 1.57:1, whereas females demonstrated a ratio of 2.72:1. The results suggest that for our group of healthy recreationally active subjects, the upper body "pushing" musculature is approximately 1.5-2.7 times stronger than the musculature involved for pulling. In this study, these recreationally active adults displayed greater strength during the timed push-ups than the modified pull-ups. The relationship of these imbalances to one's performance and or injury risk requires further investigation. The reference values, however, may serve the basis for future comparison and prospective investigations. The field tests in this study can be easily implemented by clinicians and an agonist/antagonist ratio can be determined and compared to our findings. 2b.

  12. Positive Harris recurrence and diffusion scale analysis of a push pull queueing network

    NARCIS (Netherlands)

    Nazarathy, J.; Weiss, G.

    2010-01-01

    We consider a push pull queueing network with two servers and two types of job which are processed by the two servers in opposite order, with stochastic generally distributed processing times. This push pull network was introduced by Kopzon and Weiss, who assumed exponential processing times. It is

  13. Comparison of fluoroscopy-guided pull-type percutaneous radiological gastrostomy (pull-type-PRG) with conventional percutaneous radiological gastrostomy (push-type-PRG): clinical results in 253 patients

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Schneider, J.; Dueber, C.; Pitton, M.B. [University Medical Center of the Johannes Gutenberg University Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany)

    2011-11-15

    To analyze the clinical results and complications of fluoroscopy guided internal-external pull-type percutaneous radiological gastrostomy (pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (push-type-PRG). A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in pull-type-PRG, 68% in push-type-PRG). Gastrostomy procedures were successful in 98.3% in pull-type-PRG compared to 92% in push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in pull-type-PRG (14.8% versus 34.4%, P = 0.002). Compared to the external-internal push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications. (orig.)

  14. Comparison of fluoroscopy-guided pull-type percutaneous radiological gastrostomy (pull-type-PRG) with conventional percutaneous radiological gastrostomy (push-type-PRG): clinical results in 253 patients

    International Nuclear Information System (INIS)

    Yang, Yang; Schneider, J.; Dueber, C.; Pitton, M.B.

    2011-01-01

    To analyze the clinical results and complications of fluoroscopy guided internal-external pull-type percutaneous radiological gastrostomy (pull-type-PRG) and conventional external-internal percutaneous radiological gastrostomy (push-type-PRG). A total of 253 patients underwent radiological gastrostomy between January 2002 and January 2010. Data were collected retrospectively from radiology reports, Chart review of clinical notes, procedure reports, discharge summaries and subsequent hospital visits. Statistical analysis was performed to compare the two methods for gastrostomy with respect to peri-interventional aspects and clinical results. 128 patients received the Pull-type-PRG whereas the other 125 patients were served with the Push-type-PRG. Indications for gastrostomy were similar in these two groups. The most frequent indications for the both methods were stenotic oesophageal tumors or head/neck tumors (54.7% in pull-type-PRG, 68% in push-type-PRG). Gastrostomy procedures were successful in 98.3% in pull-type-PRG compared to 92% in push-type-PRG. There was no procedure-related mortality. Compared to Push-type-PRG, the peri-interventional complication rate was significantly reduced in pull-type-PRG (14.8% versus 34.4%, P = 0.002). Compared to the external-internal push-type-PRG, the internal-external Pull-type-PRG showed a high primary success rate and a decreased incidence of peri-interventional complications. (orig.)

  15. Removal of Airborne Contaminants from a Surface Tank by a Push-Pull System

    DEFF Research Database (Denmark)

    Heiselberg, Per; Topp, Claus

    Open surface tanks are used in many industrial processes, and local exhaust systems are often designed to capture and remove toxic fumes diffused from materials in the tanks prior to their escape into the workplace environment. The push-pull system seems to be the most efficient local exhaust...... system, but proper design is required to ensure health and safety of the workers and, furthermore, it is very desirable from an energy conservation point of view to determine an optimum and -an efficient design of push-pull hoods which can exhaust all contaminants with a minimum quantity of volume flow....... The paper describes and discusses different design methods and compares designed values with results from a measurement series of push-pull system efficiency....

  16. "Location is surprisingly a lot more important than you think": a critical thematic analysis of push and pull factor messaging used on Caribbean offshore medical school websites.

    Science.gov (United States)

    Morgan, Jeffrey; Crooks, Valorie A; Sampson, Carla Jackie; Snyder, Jeremy

    2017-06-02

    Offshore medical schools are for-profit, private enterprises located in the Caribbean that provide undergraduate medical education to students who must leave the region for postgraduate training and also typically to practice. This growing industry attracts many medical students from the US and Canada who wish to return home to practice medicine. After graduation, international medical graduates can encounter challenges obtaining residency placements and can face other barriers related to practice. We conducted a qualitative thematic analysis to discern the dominant messages found on offshore medical school websites. Dominant messages included frequent references to push and pull factors intended to encourage potential applicants to consider attending an offshore medical school. We reviewed 38 English-language Caribbean offshore medical school websites in order to extract and record content pertaining to push and pull factors. We found two push and four pull factors present across most offshore medical school websites. Push factors include the: shortages of physicians in the US and Canada that require new medical trainees; and low acceptance rates at medical schools in intended students' home countries. Pull factors include the: financial benefits of attending an offshore medical school; geographic location and environment of training in the Caribbean; training quality and effectiveness; and the potential to practice medicine in one's home country. This analysis contributes to our understanding of some of the factors behind students' decisions to attend an offshore medical school. Importantly, push and pull factors do not address the barriers faced by offshore medical school graduates in finding postgraduate residency placements and ultimately practicing elsewhere. It is clear from push and pull factors that these medical schools heavily focus messaging and marketing towards students from the US and Canada, which raises questions about who benefits from this

  17. Discussion of push-pull equilibrium in well field at Yining in-situ leaching mine, Xinjiang

    International Nuclear Information System (INIS)

    Wang Haifeng; Su Xuebin

    1999-01-01

    Combined with a case of in-situ leaching project, the author discusses the principle and approaches for push-pull equilibrium controlling, and gives the suggestions solving the un-equilibrium problems of push-pull in well field during operation

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

    Science.gov (United States)

    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.

  19. Causal assessment of occupational pushing or pulling and low back pain: results of a systematic review.

    Science.gov (United States)

    Roffey, Darren M; Wai, Eugene K; Bishop, Paul; Kwon, Brian K; Dagenais, Simon

    2010-06-01

    Low back pain (LBP) is a prevalent and expensive musculoskeletal condition that predominantly occurs in working-age individuals of industrialized nations. Although numerous occupational physical activities have been implicated in its etiology, determining the causation of occupational LBP still remains a challenge. To conduct a systematic review evaluating the causal relationship between occupational pushing or pulling and LBP. Systematic review of the literature. Studies reporting an association between occupational pushing or pulling and LBP. Numerical association between exposure to pushing or pulling and the presence of LBP. A systematic review was performed to identify, evaluate, and summarize the literature related to establishing a causal relationship, according to Bradford-Hill criteria for causation for occupational pushing or pulling and LBP. A search was conducted using Medline, EMBASE, CINAHL, Cochrane Library, and OSH-ROM, gray literature, hand-searching occupational health journals, reference lists of included studies, and expert knowledge. Methodological quality was assessed using a modified Newcastle-Ottawa Scale. This search yielded 2,766 citations. Thirteen studies met the inclusion criteria. Eight were high-quality studies and five were low-quality studies. There was conflicting evidence with one high-quality study demonstrating a positive association between occupational pushing or pulling and LBP and five studies showing no relationship. One study reported a nonstatistically significant dose-response trend, four studies discussed temporality of which one indicated a positive finding, two studies discussed the biological plausibility of a causal link between occupational pushing or pulling and LBP, and no evidence was uncovered to assess the experiment criterion. A qualitative summary of existing studies was not able to find any high-quality studies that fully satisfied any of the Bradford-Hill causation criteria for occupational pushing or

  20. Determinants and magnitudes of manual force strengths and joint moments during two-handed standing maximal horizontal pushing and pulling.

    Science.gov (United States)

    Chow, Amy Y; Dickerson, Clark R

    2016-04-01

    Pushing and pulling are common occupational exertions that are increasingly associated with musculoskeletal complaints. This study focuses on the sensitivity of shoulder capacity to gender, handle height, exertion type (push or pull) and handle orientation for these tasks. All factors except for handle orientation influenced unilateral and total manual force strength (p pushing and pulling tasks for a diverse population. Practitioner Summary: pushing and pulling comprise nearly half of all manual materials handling tasks. Practitioners often assess, design or modify these tasks while incorporating constraints, including manual force direction and handle interface. This study provides guidance to aid design of pushing and pulling tasks in the context of shoulder physical capacity.

  1. Biomechanically determined hand force limits protecting the low back during occupational pushing and pulling tasks.

    Science.gov (United States)

    Weston, Eric B; Aurand, Alexander; Dufour, Jonathan S; Knapik, Gregory G; Marras, William S

    2018-06-01

    Though biomechanically determined guidelines exist for lifting, existing recommendations for pushing and pulling were developed using a psychophysical approach. The current study aimed to establish objective hand force limits based on the results of a biomechanical assessment of the forces on the lumbar spine during occupational pushing and pulling activities. Sixty-two subjects performed pushing and pulling tasks in a laboratory setting. An electromyography-assisted biomechanical model estimated spinal loads, while hand force and turning torque were measured via hand transducers. Mixed modelling techniques correlated spinal load with hand force or torque throughout a wide range of exposures in order to develop biomechanically determined hand force and torque limits. Exertion type, exertion direction, handle height and their interactions significantly influenced dependent measures of spinal load, hand force and turning torque. The biomechanically determined guidelines presented herein are up to 30% lower than comparable psychophysically derived limits and particularly more protective for straight pushing. Practitioner Summary: This study utilises a biomechanical model to develop objective biomechanically determined push/pull risk limits assessed via hand forces and turning torque. These limits can be up to 30% lower than existing psychophysically determined pushing and pulling recommendations. Practitioners should consider implementing these guidelines in both risk assessment and workplace design moving forward.

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

    Science.gov (United States)

    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.

  3. What Explains the Survival Gap of Pushed and Pulled Corporate Spin-offs?

    DEFF Research Database (Denmark)

    Rocha, Vera; Carneiro, Anabela; Varum, Celeste

    2015-01-01

    Unconditionally, pushed spin-offs are found to survive longer than their pulled counterparts. Using matched employer-employee data and novel multivariate decomposition techniques, we show that pushed spin-offs’ relative survival advantage is mostly explained by their larger human capital endowments...

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

    Science.gov (United States)

    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.

  5. Push-Pull Effects of Three Plant Secondary Metabolites on Oviposition of the Potato Tuber Moth, Phthorimaea operculella

    Science.gov (United States)

    Ma, Y.F.; Xiao, C.

    2013-01-01

    The push-pull effects of three plant secondary metabolites, azadirachtin, eucalyptol, and heptanal, on the oviposition choices of potato tubers by the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) were tested in the laboratory. Azadirachtin at concentrations from 1.5 to 12 mg/L had a significant repellent effect on oviposition. Eucalyptol at concentrations from 3 to 12 mg/L promoted oviposition. Heptanal promoted oviposition at low concentrations from 0.1875 to 3.0 mg/L but repelled it at higher concentrations from 12 to 24 mg/L. The combination of azadirachtin (12 mg/L) with eucalyptol (3.0 mg/L) resulted in a significant pushpull effect of 56.3% on oviposition. The average maximum push-pull effects occurred with the combinations of azadirachtin with heptanal (12 and 0.375 mg/L, respectively; 38.7% push-pull effect), heptanal with eucalyptol (12 and 6 mg/L, respectively; 31.4% push-pull effect), and heptanal (high concentration) with heptanal (low concentration) (12.0 and 0.375 mg/L, respectively; 25% push-pull effect). PMID:24786822

  6. Push-Pull and Feedback Mechanisms Can Align Signaling System Outputs with Inputs.

    Science.gov (United States)

    Andrews, Steven S; Peria, William J; Yu, Richard C; Colman-Lerner, Alejandro; Brent, Roger

    2016-11-23

    Many cell signaling systems, including the yeast pheromone response system, exhibit "dose-response alignment" (DoRA), in which output of one or more downstream steps closely matches the fraction of occupied receptors. DoRA can improve the fidelity of transmitted dose information. Here, we searched systematically for biochemical network topologies that produced DoRA. Most networks, including many containing feedback and feedforward loops, could not produce DoRA. However, networks including "push-pull" mechanisms, in which the active form of a signaling species stimulates downstream activity and the nominally inactive form reduces downstream activity, enabled perfect DoRA. Networks containing feedbacks enabled DoRA, but only if they also compared feedback to input and adjusted output to match. Our results establish push-pull as a non-feedback mechanism to align output with variable input and maximize information transfer in signaling systems. They also suggest genetic approaches to determine whether particular signaling systems use feedback or push-pull control. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Study on pollution control in residential kitchen based on the push-pull ventilation system

    DEFF Research Database (Denmark)

    Zhou, Bin; Chen, Feng; Dong, Zhibo

    2016-01-01

    Highlights •The push-pull ventilation system is proposed to improve IAQ inside kitchen, where air is supplied through slot air curtain and then exhausted through range hood. •CO2 reduction efficiency with application of air curtain in experiment and simulation in breathing zone was 23.7% and 23.......1%, respectively. •By orthogonal method, the influence of factors on pollution control of the push-pull ventilation system was presented....

  8. Push-you-pull-you: the boundaried self in close relationships.

    Science.gov (United States)

    Rempel, John K; Burris, Christopher T

    2006-02-01

    Based on Amoebic Self Theory, the authors propose that the salience of different threats to the self affects the extent to which an intimate relationship partner is pushed away (excluded) or pulled closer (included). When social threat is salient among persons in relationships, it is hypothesized that partners will attempt to defuse the resulting sense of interpersonal vulnerability: offending partners may be pushed away, whereas offenders themselves may draw closer. When spatial-symbolic threat is salient and the relationship's capacity to function as an identity marker is jeopardized, it is hypothesized that the partner--regardless of his or her role--will be pulled closer to maintain the perception that the relationship is secure. Self-report responses to hypothetical scenarios and perceptions of behaviors during a role-play were generally consistent with these hypotheses, suggesting that both an intimate partner and the relationship with that partner can be incorporated into the self.

  9. Exploring tourists push and pull motivations to visit Mauritius as a tourist destination

    Directory of Open Access Journals (Sweden)

    Hemant Kassean

    2013-01-01

    Full Text Available This study examines the motivational push and pull-factors that affect tourists’ decision in their choice of a holiday destination. 200 questionnaires were completed using a face to face interview among specific groups of travellers to Mauritius (English, French, German, Italian and South African tourists at various points on the island. The findings demonstrate that rest and relaxation are the most compelling push motivation forces followed by nostalgia, escape, novelty and social interaction. The key pull based motives were found to be the special climate and weather of Mauritius, the exquisite landscape and scenery, unique flora and fauna, exotic beaches, the exotic ambience and atmosphere, the welcoming nature of Mauritian hospitality and the authentic Mauritian culture. The Push and pull factors between first time visitors and repeat visitors are discussed in this article and the study essentially contributes to our overall understanding of why holiday makers take travel decisions to opt for long- haul destinations like Mauritius, and can therefore help destination marketers develop better marketing programmes to meet the specific needs of their customers.

  10. Are pushing and pulling work-related risk factors for upper extremity symptoms? A systematic review of observational studies.

    Science.gov (United States)

    Hoozemans, M J M; Knelange, E B; Frings-Dresen, M H W; Veeger, H E J; Kuijer, P P F M

    2014-11-01

    Systematically review observational studies concerning the question whether workers that perform pushing/pulling activities have an increased risk for upper extremity symptoms as compared to workers that perform no pushing/pulling activities. A search in MEDLINE via PubMed and EMBASE was performed with work-related search terms combined with push/pushing/pull/pulling. Studies had to examine exposure to pushing/pulling in relation to upper extremity symptoms. Two authors performed the literature selection and assessment of the risk of bias in the studies independently. A best evidence synthesis was used to draw conclusions in terms of strong, moderate or conflicting/insufficient evidence. The search resulted in 4764 studies. Seven studies were included, with three of them of low risk of bias, in total including 8279 participants. A positive significant relationship with upper extremity symptoms was observed in all four prospective cohort studies with effect sizes varying between 1.5 and 4.9. Two out of the three remaining studies also reported a positive association with upper extremity symptoms. In addition, significant positive associations with neck/shoulder symptoms were found in two prospective cohort studies with effect sizes of 1.5 and 1.6, and with shoulder symptoms in one of two cross-sectional studies with an effect size of 2.1. There is strong evidence that pushing/pulling is related to upper extremity symptoms, specifically for shoulder symptoms. There is insufficient or conflicting evidence that pushing/pulling is related to (combinations of) upper arm, elbow, forearm, wrist or hand symptoms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

    Science.gov (United States)

    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).

  12. Push an pull forces in the building and construction industry

    NARCIS (Netherlands)

    Frings-Dresen, M. H. W.; Windhorst, Judith; Hoozemans, M. J M; Van Der Beek, Allard J.; Van der Molen, Henk F.

    2000-01-01

    Push and pull activities are increasing in the building and construction industry. These activities can be assumed as one of the risk factors for the development of low back and upper extremity complaints. For a risk evaluation, besides the frequency and the duration of the activities, information

  13. Benchtop-magnetic resonance imaging (BT-MRI) characterization of push-pull osmotic controlled release systems.

    Science.gov (United States)

    Malaterre, Vincent; Metz, Hendrik; Ogorka, Joerg; Gurny, Robert; Loggia, Nicoletta; Mäder, Karsten

    2009-01-05

    The mechanism of drug release from push-pull osmotic systems (PPOS) has been investigated by Magnetic Resonance Imaging (MRI) using a new benchtop apparatus. The signal intensity profiles of both PPOS layers were monitored non-invasively over time to characterize the hydration and swelling kinetics. The drug release performance was well-correlated to the hydration kinetics. The results show that (i) hydration and swelling critically depend on the tablet core composition, (ii) high osmotic pressure developed by the push layer may lead to bypassing the drug layer and incomplete drug release and (iii) the hydration of both the drug and the push layers needs to be properly balanced to efficiently deliver the drug. MRI is therefore a powerful tool to get insights on the drug delivery mechanism of push-pull osmotic systems, which enable a more efficient optimization of such formulations.

  14. Relationship between interstitial and blood glucose in type 1 diabetes patients: delay and the push-pull phenomenon revisited

    NARCIS (Netherlands)

    Wentholt, Iris M. E.; Hart, Augustus A. M.; Hoekstra, Joost B. L.; DeVries, J. Hans

    2007-01-01

    BACKGROUND: Interpretation of glucose sensor results requires clarification of the relationship between interstitial (IG) and blood (BG) glucose. We examined the delay of IG upon BG change and reinvestigated the push-pull phenomenon in type 1 diabetes patients. The push-pull phenomenon postulates

  15. Field evaluation of a push-pull system to reduce malaria transmission.

    Directory of Open Access Journals (Sweden)

    David J Menger

    Full Text Available 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.

  16. Effect of a powered drive on pushing and pulling forces when transporting bariatric hospital beds.

    Science.gov (United States)

    Wiggermann, Neal

    2017-01-01

    Powered drives designed to assist with moving hospital beds are commercially available but no studies have evaluated whether they reduce the push and pull forces likely contributing to injury in caregivers. This study measured hand forces of 10 caregivers maneuvering a manual and powered bariatric bed through simulated hospital environments (hallway, elevator, and ramp). Peak push and pull forces exceeded previously established psychophysical limits for all activities with the manual bed. For the powered bed, peak forces were significantly (p pushing did not differ between beds. Powered drive may reduce the risk of injury or the number of caregivers needed for transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  18. A push-pull system to reduce house entry of malaria mosquitoes

    NARCIS (Netherlands)

    Menger, D.J.; Otieno, B.; Rijk, de M.; Mukabana, W.R.; Loon, van J.J.A.; Takken, W.

    2014-01-01

    Background. Mosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull

  19. Achieving food security for one million sub-Saharan African poor through push-pull innovation by 2020.

    Science.gov (United States)

    Khan, Zeyaur R; Midega, Charles A O; Pittchar, Jimmy O; Murage, Alice W; Birkett, Michael A; Bruce, Toby J A; Pickett, John A

    2014-04-05

    Food insecurity is a chronic problem in Africa and is likely to worsen with climate change and population growth. It is largely due to poor yields of the cereal crops caused by factors including stemborer pests, striga weeds and degraded soils. A platform technology, 'push-pull', based on locally available companion plants, effectively addresses these constraints resulting in substantial grain yield increases. It involves intercropping cereal crops with a forage legume, desmodium, and planting Napier grass as a border crop. Desmodium repels stemborer moths (push), and attracts their natural enemies, while Napier grass attracts them (pull). Desmodium is very effective in suppressing striga weed while improving soil fertility through nitrogen fixation and improved organic matter content. Both companion plants provide high-value animal fodder, facilitating milk production and diversifying farmers' income sources. To extend these benefits to drier areas and ensure long-term sustainability of the technology in view of climate change, drought-tolerant trap and intercrop plants are being identified. Studies show that the locally commercial brachiaria cv mulato (trap crop) and greenleaf desmodium (intercrop) can tolerate long droughts. New on-farm field trials show that using these two companion crops in adapted push-pull technology provides effective control of stemborers and striga weeds, resulting in significant grain yield increases. Effective multi-level partnerships have been established with national agricultural research and extension systems, non-governmental organizations and other stakeholders to enhance dissemination of the technology with a goal of reaching one million farm households in the region by 2020. These will be supported by an efficient desmodium seed production and distribution system in eastern Africa, relevant policies and stakeholder training and capacity development.

  20. Three Levels of Push-Pull Dynamics among Chinese International Students' Decision to Study Abroad in the Canadian Context

    Science.gov (United States)

    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…

  1. Inclusion at Risk? Push- and Pull-Out Phenomena in Inclusive School Systems: The Italian and Norwegian Experiences

    Science.gov (United States)

    Nes, Kari; Demo, Heidrun; Ianes, Dario

    2018-01-01

    The main objective of this article is to explore and compare research data on pull-out and push-out phenomena within inclusive school systems, discussing if and how they represent a risk for inclusion. The terms pull-out and push-out refer to situations in which some groups of students in regular schools learn in settings apart from their peers.…

  2. Push-Pull Laser-Atomic Oscillator

    International Nuclear Information System (INIS)

    Jau, Y.-Y.; Happer, W.

    2007-01-01

    A vapor of alkali-metal atoms in the external cavity of a semiconductor laser, pumped with a time-independent injection current, can cause the laser to self-modulate at the 'field-independent 0-0 frequency' of the atoms. Push-pull optical pumping by the modulated light drives most of the atoms into a coherent superposition of the two atomic sublevels with an azimuthal quantum number m=0. The atoms modulate the optical loss of the cavity at the sharply defined 0-0 hyperfine frequency. As in a maser, the system is not driven by an external source of microwaves, but a very stable microwave signal can be recovered from the modulated light or from the modulated voltage drop across the laser diode. Potential applications for this new phenomenon include atomic clocks, the production of long-lived coherent atomic states, and the generation of coherent optical combs

  3. N -annulated perylene-based push-pull-type sensitizers

    KAUST Repository

    Qi, Qingbiao; Wang, Xingzhu; Fan, Li; Zheng, Bin; Zeng, Wangdong; Luo, Jie; Huang, Kuo-Wei; Wang, Qing; Wu, Jishan

    2015-01-01

    Alkoxy-wrapped N-annulated perylene (NP) was synthesized and used as a rigid and coplanar π-linker for three push-pull type metal-free sensitizers QB1-QB3. Their optical and electrochemical properties were tuned by varying the structure of acceptor. These new dyes were applied in Co(II)/(III) based dye-sensitized solar cells, and power conversion efficiency up to 6.95% was achieved, indicating that NP could be used as a new building block for the design of high-performance sensitizers in the future.

  4. N -annulated perylene-based push-pull-type sensitizers

    KAUST Repository

    Qi, Qingbiao

    2015-02-06

    Alkoxy-wrapped N-annulated perylene (NP) was synthesized and used as a rigid and coplanar π-linker for three push-pull type metal-free sensitizers QB1-QB3. Their optical and electrochemical properties were tuned by varying the structure of acceptor. These new dyes were applied in Co(II)/(III) based dye-sensitized solar cells, and power conversion efficiency up to 6.95% was achieved, indicating that NP could be used as a new building block for the design of high-performance sensitizers in the future.

  5. Optical pulling and pushing forces exerted on silicon nanospheres with strong coherent interaction between electric and magnetic resonances.

    Science.gov (United States)

    Liu, Hongfeng; Panmai, Mingcheng; Peng, Yuanyuan; Lan, Sheng

    2017-05-29

    We investigated theoretically and numerically the optical pulling and pushing forces acting on silicon (Si) nanospheres (NSs) with strong coherent interaction between electric and magnetic resonances. We examined the optical pulling and pushing forces exerted on Si NSs by two interfering waves and revealed the underlying physical mechanism from the viewpoint of electric- and magnetic-dipole manipulation. As compared with a polystyrene (PS) NS, it was found that the optical pulling force for a Si NS with the same size is enlarged by nearly two orders of magnitude. In addition to the optical pulling force appearing at the long-wavelength side of the magnetic dipole resonance, very large optical pushing force is observed at the magnetic quadrupole resonance. The correlation between the optical pulling/pushing force and the directional scattering characterized by the ratio of the forward to backward scattering was revealed. More interestingly, it was found that the high-order electric and magnetic resonances in large Si NSs play an important role in producing optical pulling force which can be generated by not only s-polarized wave but also p-polarized one. Our finding indicates that the strong coherent interaction between the electric and magnetic resonances existing in nanoparticles with large refractive indices can be exploited to manipulate the optical force acting on them and the correlation between the optical force and the directional scattering can be used as guidance. The engineering and manipulation of optical forces will find potential applications in the trapping, transport and sorting of nanoparticles.

  6. Simplified method of ''push-pull'' test data analysis for determining in situ reaction rate coefficients

    International Nuclear Information System (INIS)

    Haggerty, R.; Schroth, M.H.; Istok, J.D.

    1998-01-01

    The single-well, ''''push-pull'''' test method is useful for obtaining information on a wide variety of aquifer physical, chemical, and microbiological characteristics. A push-pull test consists of the pulse-type injection of a prepared test solution into a single monitoring well followed by the extraction of the test solution/ground water mixture from the same well. The test solution contains a conservative tracer and one or more reactants selected to investigate a particular process. During the extraction phase, the concentrations of tracer, reactants, and possible reaction products are measured to obtain breakthrough curves for all solutes. This paper presents a simplified method of data analysis that can be used to estimate a first-order reaction rate coefficient from these breakthrough curves. Rate coefficients are obtained by fitting a regression line to a plot of normalized concentrations versus elapsed time, requiring no knowledge of aquifer porosity, dispersivity, or hydraulic conductivity. A semi-analytical solution to the advective-dispersion equation is derived and used in a sensitivity analysis to evaluate the ability of the simplified method to estimate reaction rate coefficients in simulated push-pull tests in a homogeneous, confined aquifer with a fully-penetrating injection/extraction well and varying porosity, dispersivity, test duration, and reaction rate. A numerical flow and transport code (SUTRA) is used to evaluate the ability of the simplified method to estimate reaction rate coefficients in simulated push-pull tests in a heterogeneous, unconfined aquifer with a partially penetrating well. In all cases the simplified method provides accurate estimates of reaction rate coefficients; estimation errors ranged from 0.1 to 8.9% with most errors less than 5%

  7. Evaluation of Interhandle Distance During Pushing and Pulling of a Four-Caster Cart for Upper Limb Exertion.

    Science.gov (United States)

    Ohnishi, Akihiro; Takanokura, Masato; Sugama, Atsushi

    2016-09-01

    This study examined the relationship between interhandle distances and upper limb exertion during simply pushing and pulling of a cart with four swivel wheels, defined by a roll box pallet (RBP) in a Japanese industrial standard. Six healthy young male participants were asked to push and pull an RBP at a distance of 5.2 m under six conditions corresponding to different interhandle distances (40 cm, 60 cm, and 80 cm) and weights (130 kg and 250 kg). The upper limb exertion was studied by shoulder abduction and flexion, and elbow flexion, as well as surface electromyogram (EMG) in shoulder extensor, and elbow flexor and extensor. Participants were required to provide subjective evaluations on operability after each trial. Subjective operability indicated that a narrower interhandle distance had a better operability for pushing. Interhandle distance was also related to upper limb exertion especially for pushing. A narrow interhandle distance caused smaller shoulder adduction but larger elbow flexion. The normalized EMG data revealed that muscular activity became smaller with a narrow interhandle distance in shoulder extensor. During the pulling task, elbow flexion was smaller at a narrow interhandle distance, although subjective operability and normalized EMG were not significantly varied. A wider interhandle distance, such as 80 cm, was not suitable in the forwardbackward movement of the RBP. Therefore, this study concluded that an interhandle distance of 40 cm would be suitable for pushing and pulling an RBP to protect the workers' hands against the risk of injury by installing inner handles.

  8. Modelo híbrido pull-push en el sector de las telecomunicaciones

    Directory of Open Access Journals (Sweden)

    Cristian Arlex Trejos Taborda

    2016-07-01

    Full Text Available La industria de las telecomunicaciones cambia rápidamente y las barreras de entrada son bajas implicando que la supervivencia en el mercado sea un verdadero desafío para las empresas. En este artículo estudia como los sistemas Pull y Push pueden ser integrados a la cadena de abastecimiento en el sector de telecomunicaciones en Colombia. Se desarrolló un modelo hibrido Pull y Push utilizando dinámica de sistemas en aras de determinar los niveles óptimos y el costo mínimo de inventario, al igual que el nivel óptimo de prestación de servicio a los clientes. Los resultados de la investigación demuestran que el comportamiento del modelo híbrido permite dar respuesta a las necesidades del mercado y de la empresa a la vez, generando niveles de inventario que son mínimos y suficientes para cubrir la demanda.

  9. Evaluation of methods to assess push/pull forces in a construction task

    NARCIS (Netherlands)

    Hoozemans, M J; Van Der Beek, Allard J.; Frings-Dresena, M H; Van der Molen, Henk F.

    2001-01-01

    The objective of the present study was to determine the validity of methods to assess push/pull forces exerted in a construction task. Forces assessed using a hand-held digital force gauge were compared to those obtained using a highly accurate measuring frame. No significant differences were found

  10. Control and Modeling of Push-Pull Forward Three-Level Converter for Microgrid

    DEFF Research Database (Denmark)

    Yao, Zhilei; Xu, Jing; Guerrero, Josep M.

    2015-01-01

    Renewable energy sources are widely used in microgrid. Output voltage of them is often low and varies widely. Because diodes in three-level legs in traditional three-level (TL) converter are substituted by MOSFETs, the push-pull forward (PPF) TL converter is very suitable for wide and low...

  11. Initial Assessment of the Acceptability of a Push-Pull Aedes aegypti Control Strategy in Iquitos, Peru and Kanchanaburi, Thailand

    Science.gov (United States)

    Paz-Soldan, Valerie A.; Plasai, Valaikanya; Morrison, Amy C.; Rios-Lopez, Esther J.; Guedez-Gonzales, Shirly; Grieco, John P.; Mundal, Kirk; Chareonviriyaphap, Theeraphap; Achee, Nicole L.

    2011-01-01

    As part of a larger research program evaluating chemical threshold levels for a Push-Pull intervention to reduce man-vector (Aedes aegypti) contact, this qualitative study explored local perceptions and strategies associated with mosquito control within dengue-endemic communities in Peru and Thailand. Focus groups were used to provide preliminary information that would identify possible public acceptance issues to the Push-Pull strategy in each site. Nine focus group discussions (total of 102 individuals) conducted between September 2008 and March 2009 examined several themes: 1) current mosquito control practices; 2) perceptions of spatial repellency and contact irritancy versus killing mosquitoes; and 3) initial perceptions toward mosquito host-seeking traps. Results indicate participants use household-level strategies for insect control that reveal familiarity with the concept of spatial repellent and contact irritant actions of chemicals and that placing traps in the peridomestic environment to remove repelled mosquitoes was acceptable. Preliminary evidence suggests a Push-Pull strategy should be well accepted in these locations. These results will be beneficial for developing future large scale push-pull interventions and are currently being used to guide insecticide application strategies in (entomological) proof-of-concept studies using experimental huts. PMID:21292886

  12. Pushing and pulling in relation to musculoskeletal disorders : a review of risk factors

    NARCIS (Netherlands)

    Hoozemans, M J; Van Der Beek, Allard J.; Frings-Dresen, M. H. W.; Dijk, F.J.H.; van der Woude, L H

    The objective was to review the literature on risk factors for musculoskeletal disorders related to pushing and pulling. The risk factors have been described and evaluated from four perspectives: epidemiology, psychophysics, physiology, and biomechanics. Epidemiological studies have shown, based on

  13. Pushing and pulling in relation to musculoskeletal disorders: a review of risk factors

    NARCIS (Netherlands)

    Hoozemans, Marco; van der Beek, A.J.; Frings-Dresen, M.H.W.; Dijk, F.J.H.

    1998-01-01

    The objective was to review the literature on risk factors for musculoskeletal disorders related to pushing and pulling. The risk factors have been described and evaluated from four perspectives: epidemiology, psychophysics, physiology, and biomechanics. Epidemiological studies have shown, based on

  14. Mechanical load on the low back and shoulders during pushing and pulling of two-wheeled waste containers compared with lifting and carrying of bags and bins.

    Science.gov (United States)

    Schibye, B; Søgaard, K; Martinsen, D; Klausen, K

    2001-08-01

    Compare the mechanical load on the low back and shoulders during pushing and pulling a two-wheeled container with the load during lifting and carrying the same amount of waste. Only little is known about risk factors and mechanical loads during push/pull operations. A complete 2(3) factor push/pull experiment. A two-wheeled container with 25 or 50 kg was pushed in front of and pulled behind the body by seven waste collectors. Further, the same subjects lifted and carried a paper bag and a dustbin both loaded with 7 and 25 kg. All operations were video recorded and the push/pull force was measured by means of a three-dimensional force transducer. Peak Motus and Watbak software were used for digitising and calculation of torque at L4/L5 and the shoulder joints and compression and shear forces at L4/L5. During pushing and pulling the compression at L4/L5 is from 605 to 1445 N. The extension torque at L4/L5 produced by the push/pull force is counteracted by the forward leaning of the upper body. The shear force is below 202 N in all situations. The torque at the shoulders is between 1 and 38 Nm. In the present experiments the torques at the low back and the shoulders are low during pushing and pulling. No relation exists between the size of the external force and the torque at the low back and the shoulder. Pushing and pulling are common in many workplaces and have often replaced lifting and carrying situations. This has emphasised the need for more knowledge of the internal mechanical load on the body during these activities.

  15. Synthesis and characterization of a push-pull terpolymer based on anthracene, fluorene and benzothiadiazole

    Energy Technology Data Exchange (ETDEWEB)

    Floriano, Ana Carolina; Silveira, Daiana Santos; Cristovan, Fernando Henrique, E-mail: carolina.floriano@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil); Rosa, Gabriel Marques; Liao, Luciano Morais [Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Piovessan, Erick [Universidade Federal de Uberlandia (UFU), MG (Brazil)

    2016-07-01

    Full text: The development of organic optoelectronic devices with higher efficiency required new forms of polymers with strong donor-acceptor character (D-A), called a push-pull polymers. Most studies of organic polymers used in optoelectronic applications are centered on poly(3-hexylthiophene) with high regioregularity. However, there are other polymers synthesized with monomers that enables the possibility to adapt its electrical and optical properties. Polyfluorene derivatives show interesting chemical and physical properties due to a rigid planar biphenyl unit that are easily substituted at the remote C-9 position, improving the its processability in relation to polyfluorene, so it can be can be processed by spin-coating and many others deposition techniques. Fluorene derivatives copolymers prepared with anthracene unit improve electrochemical properties and present good photo and electroluminescence properties, due to an enhancement of the system conjugation. The benzothiadiazole, known by their environmental stability, planarity and electron-withdrawing nature, are a promising molecule in push−pull type semiconducting polymers. In this study proceed with the terpolymer synthesis containing 9,9-Dihexylfluorene and anthracene as pushing unit and benzothiadiazole as pushing unit. Also we synthesized the poly(9,9-dihexylfluorene)-co-(anthracene) and poly(9,9- dihexylfluorene)-co-(benzothiadiazole) copolymers. The polymers were synthesized using Suzuki coupling and characterized by FT-IR spectroscopy that shows the characteristic monomer bands and the polymer formation were confirmed by {sup 1}H-NMR. Polymerization yield of three polymers were about 50-70%. Polymers present good solubility in common organic solvent such as chloroform. Terpolymer UV-Vis spectra revealed broadband absorbance from 300 to 680nm and absorption maximum at 441 nm. Finally, the preliminary results indicate that the push-pull terpolymer is a promising broadband absorbing polymer for

  16. Synthesis and characterization of a push-pull terpolymer based on anthracene, fluorene and benzothiadiazole

    International Nuclear Information System (INIS)

    Floriano, Ana Carolina; Silveira, Daiana Santos; Cristovan, Fernando Henrique; Rosa, Gabriel Marques; Liao, Luciano Morais; Piovessan, Erick

    2016-01-01

    Full text: The development of organic optoelectronic devices with higher efficiency required new forms of polymers with strong donor-acceptor character (D-A), called a push-pull polymers. Most studies of organic polymers used in optoelectronic applications are centered on poly(3-hexylthiophene) with high regioregularity. However, there are other polymers synthesized with monomers that enables the possibility to adapt its electrical and optical properties. Polyfluorene derivatives show interesting chemical and physical properties due to a rigid planar biphenyl unit that are easily substituted at the remote C-9 position, improving the its processability in relation to polyfluorene, so it can be can be processed by spin-coating and many others deposition techniques. Fluorene derivatives copolymers prepared with anthracene unit improve electrochemical properties and present good photo and electroluminescence properties, due to an enhancement of the system conjugation. The benzothiadiazole, known by their environmental stability, planarity and electron-withdrawing nature, are a promising molecule in push−pull type semiconducting polymers. In this study proceed with the terpolymer synthesis containing 9,9-Dihexylfluorene and anthracene as pushing unit and benzothiadiazole as pushing unit. Also we synthesized the poly(9,9-dihexylfluorene)-co-(anthracene) and poly(9,9- dihexylfluorene)-co-(benzothiadiazole) copolymers. The polymers were synthesized using Suzuki coupling and characterized by FT-IR spectroscopy that shows the characteristic monomer bands and the polymer formation were confirmed by 1 H-NMR. Polymerization yield of three polymers were about 50-70%. Polymers present good solubility in common organic solvent such as chloroform. Terpolymer UV-Vis spectra revealed broadband absorbance from 300 to 680nm and absorption maximum at 441 nm. Finally, the preliminary results indicate that the push-pull terpolymer is a promising broadband absorbing polymer for

  17. Push versus pull gastrostomy in cancer patients: A single center retrospective analysis of complications and technical success rates.

    Science.gov (United States)

    Currie, B M; Getrajdman, G I; Covey, A M; Alago, W; Erinjeri, J P; Maybody, M; Boas, F E

    2018-04-28

    To compare the technical success and complication rates of push versus pull gastrostomy tubes in cancer patients, and to examine their dependence on operator experience. A retrospective review was performed of 304 cancer patients (170 men, 134 women; mean age 60.3±12.6 [SD], range: 19-102 years) referred for primary gastrostomy tube placement, 88 (29%) of whom had a previously unsuccessful attempt at percutaneous endoscopic gastrostomy (PEG) placement. Analyzed variables included method of insertion (push versus pull), indication for gastrostomy, technical success, operator experience, and procedure-related complications within 30 days of placement. Gastrostomy tubes were placed for feeding in 189 patients and palliative decompression in 115 patients. Technical success was 91%: 78% after endoscopy had previously been unsuccessful and 97% when excluding failures associated with prior endoscopy. In the first 30 days, there were 29 minor complications (17.2%) associated with push gastrostomies, and only 8 minor complications (7.5%) with pull gastrostomies (Ptechnical success rates for more versus less experienced operators. Pull gastrostomy tube placement had a lower rate of complications than push gastrostomy tube placement, especially when the indication was decompression. The technical success rate was high, even after a failed attempt at endoscopic placement. Both the rates of success and complications were independent of operator experience. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  18. Kinematics and kinetics of the bench-press and bench-pull exercises in a strength-trained sporting population.

    Science.gov (United States)

    Pearson, Simon N; Cronin, John B; Hume, Patria A; Slyfield, David

    2009-09-01

    Understanding how loading affects power production in resistance training is a key step in identifying the most optimal way of training muscular power - an essential trait in most sporting movements. Twelve elite male sailors with extensive strength-training experience participated in a comparison of kinematics and kinetics from the upper body musculature, with upper body push (bench press) and pull (bench pull) movements performed across loads of 10-100% of one repetition maximum (1RM). 1RM strength and force were shown to be greater in the bench press, while velocity and power outputs were greater for the bench pull across the range of loads. While power output was at a similar level for the two movements at a low load (10% 1RM), significantly greater power outputs were observed for the bench pull in comparison to the bench press with increased load. Power output (Pmax) was maximized at higher relative loads for both mean and peak power in the bench pull (78.6 +/- 5.7% and 70.4 +/- 5.4% of 1RM) compared to the bench press (53.3 +/- 1.7% and 49.7 +/- 4.4% of 1RM). Findings can most likely be attributed to differences in muscle architecture, which may have training implications for these muscles.

  19. Optimal Design of a Push-Pull-Forward Half-Bridge (PPFHB) Bidirectional DC–DC Converter With Variable Input Voltage

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency tr......This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high...

  20. From the Push of Fear, to the Pull of Hope: Learning by design ...

    African Journals Online (AJOL)

    From the Push of Fear, to the Pull of Hope: Learning by design. S Sterling. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · Creative Commons License This work is licensed under a Creative Commons Attribution 3.0 License.

  1. Mechanical loading of the low back and shoulders during pushing and pulling activities.

    NARCIS (Netherlands)

    Hoozemans, M.J.M.; Kingma, I.; Dieen, van J.H.; Vries, de W.K.H.; Woude, van der L.H.V.; Veeger, H.E.J.; Frings-Dresen, M.H.W.; Beek, van der A.J.

    2004-01-01

    The objective of this study was to quantify the mechanical load on the low back and shoulders during pushing and pulling in combination with three task constraints: the use of one or two hands, three cart weights, and two handle heights. The second objective was to explore the relation between the

  2. Mechanical loading of the low back and shoulders during pushing and pulling activities

    NARCIS (Netherlands)

    Hoozemans, Marco J. M.; Kuijer, P. Paul F. M.; Kingma, Idsart; van Dieën, Jaap H.; de Vries, Wiebe H. K.; van der Woude, Luc H. V.; Veeger, Dirk Jan H. E. J.; van der Beek, Allard J.; Frings-Dresen, Monique H. W.

    2004-01-01

    The objective of this study was to quantify the mechanical load on the low back and shoulders during pushing and pulling in combination with three task constraints: the use of one or two hands, three cart weights, and two handle heights. The second objective was to explore the relation between the

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

    Science.gov (United States)

    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…

  4. Laser pushing or pulling of absorbing airborne particles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chuji, E-mail: cw175@msstate.edu; Gong, Zhiyong [Mississippi State University, Starkville, Mississippi 39759 (United States); Pan, Yong-Le; Videen, Gorden [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)

    2016-07-04

    A single absorbing particle formed by carbon nanotubes in the size range of 10–50 μm is trapped in air by a laser trapping beam and concurrently illuminated by another laser manipulating beam. When the trapping beam is terminated, the movement of the particle controlled by the manipulating beam is investigated. We report our observations of light-controlled pushing and pulling motions. We show that the movement direction has little relationship with the particle size and manipulating beam's parameters but is dominated by the particle's orientation and morphology. With this observation, the controllable optical manipulation is now able to be generalized to arbitrary particles, including irregularly shaped absorbing particles that are shown in this work.

  5. Small-scale field evaluation of push-pull system against early- and outdoor-biting malaria mosquitoes in an area of high pyrethroid resistance in Tanzania [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Arnold S. Mmbando

    2017-11-01

    Full Text Available Background: Despite high coverage of indoor interventions like insecticide-treated nets, mosquito-borne infections persist, partly because of outdoor-biting, early-biting and insecticide-resistant vectors. Push-pull systems, where mosquitoes are repelled from humans and attracted to nearby lethal targets, may constitute effective complementary interventions. Methods: A partially randomized cross-over design was used to test efficacy of push-pull in four experimental huts and four local houses, in an area with high pyrethroid resistance in Tanzania. The push-pull system consisted of 1.1% or 2.2% w/v transfluthrin repellent dispensers and an outdoor lure-and-kill device (odour-baited mosquito landing box. Matching controls were set up without push-pull. Adult male volunteers collected mosquitoes attempting to bite them outdoors, but collections were also done indoors using exit traps in experimental huts and by volunteers in the local houses. The collections were done hourly (1830hrs-0730hrs and mosquito catches compared between push-pull and controls. An. gambiae s.l. and An. funestus s.l. were assessed by PCR to identify sibling species, and ELISA to detect Plasmodium falciparum and blood meal sources. Results: Push-pull in experimental huts reduced outdoor-biting for An. arabiensis and Mansonia species by 30% and 41.5% respectively. However, the reductions were marginal and insignificant for An. funestus (12.2%; p>0.05 and Culex (5%; p>0.05. Highest protection against all species occurred before 2200hrs. There was no significant difference in number of mosquitoes inside exit traps in huts with or without push-pull. In local households, push-pull significantly reduced indoor and outdoor-biting of An. arabiensis by 48% and 25% respectively, but had no effect on other species. Conclusion: This push-pull system offered modest protection against outdoor-biting An. arabiensis, without increasing indoor mosquito densities. Additional experimentation

  6. Transformation from a Single Antenna to a Series Array Using Push/Pull Origami

    Directory of Open Access Journals (Sweden)

    Syed Imran Hussain Shah

    2017-08-01

    Full Text Available We propose a push/pull origami antenna, transformable between a single antenna element and a three-element array. In limited space, the proposed origami antenna can work as a single antenna. When the space is not limited and a higher gain is required, the proposed origami antenna can be transformed to a series antenna array by pulling the frame. In order to push the antenna array back to a single antenna, the frame for each antenna element size must be different. The frame and supporting dielectric materials are built using a three-dimensional (3D printer. The conductive patterns are inkjet-printed on paper. Thus, the proposed origami antenna is built using hybrid printing technology. The 10-dB impedance bandwidth is 2.5–2.65 GHz and 2.48–2.62 GHz for the single-antenna and array mode, respectively, and the peak gains in the single-antenna and array mode are 5.8 dBi and 7.6 dBi, respectively. The proposed antenna can be used for wireless remote-sensing applications.

  7. Transformation from a Single Antenna to a Series Array Using Push/Pull Origami.

    Science.gov (United States)

    Shah, Syed Imran Hussain; Lim, Sungjoon

    2017-08-26

    We propose a push/pull origami antenna, transformable between a single antenna element and a three-element array. In limited space, the proposed origami antenna can work as a single antenna. When the space is not limited and a higher gain is required, the proposed origami antenna can be transformed to a series antenna array by pulling the frame. In order to push the antenna array back to a single antenna, the frame for each antenna element size must be different. The frame and supporting dielectric materials are built using a three-dimensional (3D) printer. The conductive patterns are inkjet-printed on paper. Thus, the proposed origami antenna is built using hybrid printing technology. The 10-dB impedance bandwidth is 2.5-2.65 GHz and 2.48-2.62 GHz for the single-antenna and array mode, respectively, and the peak gains in the single-antenna and array mode are 5.8 dBi and 7.6 dBi, respectively. The proposed antenna can be used for wireless remote-sensing applications.

  8. Evaluation of sulfate reduction at experimentally induced mixing interfaces using small-scale push-pull tests in an aquifer-wetland system

    International Nuclear Information System (INIS)

    Kneeshaw, Tara A.; McGuire, Jennifer T.; Smith, Erik W.; Cozzarelli, Isabelle M.

    2007-01-01

    This paper presents small-scale push-pull tests designed to evaluate the kinetic controls on SO 4 2- reduction in situ at mixing interfaces between a wetland and aquifer impacted by landfill leachate at the Norman Landfill research site, Norman, OK. Quantifying the rates of redox reactions initiated at interfaces is of great interest because interfaces have been shown to be zones of increased biogeochemical transformations and thus may play an important role in natural attenuation. To mimic the aquifer-wetland interface and evaluate reaction rates, SO 4 2- -rich anaerobic aquifer water (∼100mg/LSO 4 2- ) was introduced into SO 4 2- -depleted wetland porewater via push-pull tests. Results showed SO 4 2- reduction was stimulated by the mixing of these waters and first-order rate coefficients were comparable to those measured in other push-pull studies. However, rate data were complex involving either multiple first-order rate coefficients or a more complex rate order. In addition, a lag phase was observed prior to SO 4 2- reduction that persisted until the mixing interface between test solution and native water was recovered, irrespective of temporal and spatial constraints. The lag phase was not eliminated by the addition of electron donor (acetate) to the injected test solution. Subsequent push-pull tests designed to elucidate the nature of the lag phase support the importance of the mixing interface in controlling terminal electron accepting processes. These data suggest redox reactions may occur rapidly at the mixing interface between injected and native waters but not in the injected bulk water mass. Under these circumstances, push-pull test data should be evaluated to ensure the apparent rate is actually a function of time and that complexities in rate data be considered

  9. Integration of market pull and technology push in the corporate front end and innovation management - Insights from the German software industry

    DEFF Research Database (Denmark)

    Brem, Alexander; Voigt, K.-I.

    2009-01-01

    Within the framework of this paper, an extensive literature overview of technology and innovation management aspects on market pull and technology push will be given. The existing classification of market pull and technology push will be particularly shown and called into question by suggesting...... a conceptual framework. Additionally, the most common front end innovation models will be introduced. Finally, the authors will introduce how a technology-based service company is managing the connection of these two alternatives. A special focus will be laid on the accordant methods in order to search...... will be introduced as to how market pull and technology push activities within the corporate technology and innovation management can be integrated. Hence, the purpose of the paper is to introduce a theory-based conceptual framework that can be used in today’s corporate environment. In this context, technology...

  10. Do PhDs Voluntarily Opt for Private Sector Employment? Evidence of Push and Pull Effects on Mobility Choices

    DEFF Research Database (Denmark)

    Pedersen, Heidi Skovgaard

    2014-01-01

    In Denmark, policy makers have increased admissions to PhD programs to ensure the flow of researchers into the private sector, thereby increasing knowledge transfer. However, we know little about the factors influencing the sector mobility of PhD graduates. While opting for employment...... in the private sector might be driven by personal preferences, there might also be external factors pushing PhDs to choose the private sector. This article examines the push and pull effects on mobility choices using duration models to estimate the transition rates to private sector employment. The analyses show...... that the preference for and ability to do academic science reduces transition rates to the private sector, whereas being in a research position and earnings potential are attractors to the private sector. Hence, both push and pull effects determine sector mobility. Once the initial sector choice has been made...

  11. The Effects of Direction of Exertion, Path, and Load Placement in Nursing Cart Pushing and Pulling Tasks: An Electromyographical Study.

    Science.gov (United States)

    Kao, Huei Chu; Lin, Chiuhsiang Joe; Lee, Yung Hui; Chen, Su Huang

    2015-01-01

    The purpose of this study was to explore the effects of direction of exertion (DOE) (pushing, pulling), path (walking in a straight line, turning left, walking uphill), and load placement (LP) (the 18 blocks were indicated by X, Y and Z axis; there were 3 levels on the X axis, 2 levels on the Y axis, and 3 levels on the Z axis) on muscle activity and ratings of perceived exertion in nursing cart pushing and pulling tasks. Ten participants who were female students and not experienced nurses were recruited to participate in the experiment. Each participant performed 108 experimental trials in the study, consisting of 2 directions of exertion (push and pull), 3 paths, and 18 load placements (indicated by X, Y and Z axes). A 23kg load was placed into one load placement. The dependent variables were electromyographic (EMG) data of four muscles collected bilaterally as follows: Left (L) and right (R) trapezius (TR), flexor digitorum superficialis (FDS), extensor digitorum (ED), and erector spinae (ES) and subjective ratings of perceived exertion (RPE). Split-split-plot ANOVA was conducted to analyze significant differences between DOE, path, and LP in the EMG and RPE data. Pulling cart tasks produced a significantly higher activation of the muscles (RTR:54.4%, LTR:50.3%, LFDS:57.0%, LED:63.4%, RES:40.7%, LES:36.7%) than pushing cart tasks (RTR:42.4%, LTR:35.1%, LFDS:32.3%, LED:55.1%, RES:33.3%, LES:32.1%). A significantly greater perceived exertion was found in pulling cart tasks than pushing cart tasks. Significantly higher activation of all muscles and perceived exertion were observed for walking uphill than walking in a straight line and turning left. Significantly lower muscle activity of all muscles and subject ratings were observed for the central position on the X axis, the bottom position on the Y axis, and the posterior position on the Z axis. These findings suggest that nursing staff should adopt forward pushing when moving a nursing cart, instead of backward

  12. Subtle trade-off existing between (anti)aromaticity, push-pull interaction, keto-enol tautomerism, and steric hindrance when defining the electronic properties of conjugated structures.

    Science.gov (United States)

    Kleinpeter, Erich; Bölke, Ute; Koch, Andreas

    2010-07-22

    The spatial magnetic properties (through space NMR shieldings, TSNMRS) of conjugated structures (benzenoid/quinonoid keto/enol tautomers, 1,3-dihydroxyaryl-2-aldehydes, Don-pi-Acc chromophores with trade-off existing push-pull vs aromatic behavior) have been calculated by the GIAO perturbation method employing the nucleus independent chemical shift (NICS) concept, and visualized as iso-chemical-shielding surfaces (ICSS) of various size and direction. The TSNMRS values, thus obtained, can be successfully employed to quantify and visualize (anti)aromaticity and to identify readily hereby zwitterionic structures due to push-pull behavior of the compounds studied. In addition, the push-pull behavior was quantified by the quotient (pi*/pi) approach of the central partial C=C double bond.

  13. Impact of hand forces and start/stop frequency on physiological responses to three forms of pushing and pulling: a South African perspective.

    Science.gov (United States)

    Ai, Todd

    2012-01-01

    There has been limited attention given to the physiological demands of pushing and pulling, especially in industrially developing countries such as South Africa. Two key factors affecting the physiological demands of these tasks are the hand forces exerted and the start/stop frequency. The purpose of the current study was therefore to investigate the physiological responses to pushing and pulling at various loads and start/stop frequencies. 36 male subjects participated in the study and were required to complete a total of 18 conditions (three techniques: pushing, two- and one-handed pulling; three loads: 200, 350 and 500 kg; and two frequencies: 2 and 4 stops per minute). During each condition the heart rate, oxygen uptake and energy expenditure were measured. Pushing was found to elicit significantly lower responses for all three dependent variables than either form of pulling. The start/stop frequency was also found to have a significant impact on subject responses. The findings of this study indicate that the technique adopted to maneuver loads is critical in determining the physical demands placed on the human operator. Furthermore increasing the frequency of start/stops plays an important role, thus the forces exerted during these two phases are important from a physiological perspective.

  14. An innovative and efficient method to control the shape of push-pull membrane deformable mirror

    NARCIS (Netherlands)

    Polo, A.; Haber, A.; Pereira, S.F.; Verhaegen, M.H.G.; Urbach, H.P.

    2012-01-01

    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

  15. Ion Concentration- and Voltage-Dependent Push and Pull Mechanisms of Potassium Channel Ion Conduction.

    Directory of Open Access Journals (Sweden)

    Kota Kasahara

    Full Text Available The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD simulations with several different voltages and ion concentrations. By focusing on the detailed ion movements through the pore including selectivity filter (SF and cavity, we found two major conduction mechanisms, called the III-IV-III and III-II-III mechanisms, and the balance between the ion concentration and the voltage determines the mechanism preference. In the III-IV-III mechanism, the outermost ion in the pore is pushed out by a new ion coming from the intracellular fluid, and four-ion states were transiently observed. In the III-II-III mechanism, the outermost ion is pulled out first, without pushing by incoming ions. Increases in the ion concentration and voltage accelerated ion conductions, but their mechanisms were different. The increase in the ion concentrations facilitated the III-IV-III conductions, while the higher voltages increased the III-II-III conductions, indicating that the pore domain of potassium channels permeates ions by using two different driving forces: a push by intracellular ions and a pull by voltage.

  16. Simulation and optimization of a polymer directional coupler electro-optic switch with push pull electrodes

    Science.gov (United States)

    Zheng, Chuan-Tao; Ma, Chun-Sheng; Yan, Xin; Wang, Xian-Yin; Zhang, Da-Ming

    2008-07-01

    Structural model and design technique are proposed for a polymer directional coupler electro-optic switch with rib waveguides and push-pull electrodes, of which the electric field distribution is analyzed by the conformal transforming method and image method. In order to get the minimum mode loss and the minimum switching voltage, the parameters of the waveguide and electrode are optimized, such as the core with, core thickness, buffer layer between the core and the electrode, coupling gap between the waveguides, electrode thickness, electrode width and electrode gap. Switching Characteristics are analyzed, which include the output power, insertion loss, and crosstalk. To realize normal switching function, the fabrication error, spectrum shift, and coupling loss between a single mode fiber (SMF) and the waveguide are discussed. Simulation results show that the coupling length is 3082 μm, push-pull switching voltage is 2.14 V, insertion loss is less than 1.17 dB, and crosstalk is less than -30 dB for the designed device.

  17. Human Body Mechanics of Pushing and Pulling: Analyzing the Factors of Task-related Strain on the Musculoskeletal System.

    Science.gov (United States)

    Argubi-Wollesen, Andreas; Wollesen, Bettina; Leitner, Martin; Mattes, Klaus

    2017-03-01

    The purpose of this review is to name and describe the important factors of musculoskeletal strain originating from pushing and pulling tasks such as cart handling that are commonly found in industrial contexts. A literature database search was performed using the research platform Web of Science. For a study to be included in this review differences in measured or calculated strain had to be investigated with regard to: (1) cart weight/ load; (2) handle position and design; (3) exerted forces; (4) handling task (push and pull); or (5) task experience. Thirteen studies met the inclusion criteria and proved to be of adequate methodological quality by the standards of the Alberta Heritage Foundation for Medical Research. External load or cart weight proved to be the most influential factor of strain. The ideal handle positions ranged from hip to shoulder height and were dependent on the strain factor that was focused on as well as the handling task. Furthermore, task experience and subsequently handling technique were also key to reducing strain. Workplace settings that regularly involve pushing and pulling should be checked for potential improvements with regards to lower weight of the loaded handling device, handle design, and good practice guidelines to further reduce musculoskeletal disease prevalence.

  18. Finding the Cell Center by a Balance of Dynein and Myosin Pulling and Microtubule Pushing: A Computational Study

    Science.gov (United States)

    Zhu, Jie; Burakov, Anton; Rodionov, Vladimir

    2010-01-01

    The centrosome position in many types of interphase cells is actively maintained in the cell center. Our previous work indicated that the centrosome is kept at the center by pulling force generated by dynein and actin flow produced by myosin contraction and that an unidentified factor that depends on microtubule dynamics destabilizes position of the centrosome. Here, we use modeling to simulate the centrosome positioning based on the idea that the balance of three forces—dyneins pulling along microtubule length, myosin-powered centripetal drag, and microtubules pushing on organelles—is responsible for the centrosome displacement. By comparing numerical predictions with centrosome behavior in wild-type and perturbed interphase cells, we rule out several plausible hypotheses about the nature of the microtubule-based force. We conclude that strong dynein- and weaker myosin-generated forces pull the microtubules inward competing with microtubule plus-ends pushing the microtubule aster outward and that the balance of these forces positions the centrosome at the cell center. The model also predicts that kinesin action could be another outward-pushing force. Simulations demonstrate that the force-balance centering mechanism is robust yet versatile. We use the experimental observations to reverse engineer the characteristic forces and centrosome mobility. PMID:20980619

  19. The strategic ''pull'' and operational ''push'' of total quality management in UK regional electricity service companies

    Energy Technology Data Exchange (ETDEWEB)

    McAdam, R.; McLean, J.; Henderson, J.

    2003-04-30

    The aim of this paper is to evaluate whether the UK regional electricity companies (RECs) has used total quality management (TQM) as a ''push'' or as a ''pull'' change methodology. ''Push'' is the operational improvement role of TQM; ''pull'' is the strategic or direction giving, improvement role of TQM. Following the onset of privatisation in 1990 there has been evidence of the RECs adopting TQM in both ''push'' and ''pull'' methodologies with varying degrees of success. An evaluation of the change processes involved will enable improved change models to be developed leading to increased business effectiveness in this 30 billion pounds sterling industry. Other possible benefits include the possible generalisations to other utilities such as water, roads, gas and telecoms. The research methodology includes a comparative case study analysis of five RECs, which have used TQM as their overarching approach to change. One of the cases is analysed to a more in-depth level based on the multiple case findings. The findings indicate that the ''push-pull'' analysis enables the full range of TQM activities to be evaluated in the RECs studied. Overall, there is a need to have a balanced portfolio of operational or ''push''-based TQM activity that is driven by strategic or ''pull'' based TQM planning and activity. (author)

  20. Optimal Halbach Permanent Magnet Designs for Maximally Pulling and Pushing Nanoparticles.

    Science.gov (United States)

    Sarwar, A; Nemirovski, A; Shapiro, B

    2012-03-01

    Optimization methods are presented to design Halbach arrays to maximize the forces applied on magnetic nanoparticles at deep tissue locations. In magnetic drug targeting, where magnets are used to focus therapeutic nanoparticles to disease locations, the sharp fall off of magnetic fields and forces with distances from magnets has limited the depth of targeting. Creating stronger forces at depth by optimally designed Halbach arrays would allow treatment of a wider class of patients, e.g. patients with deeper tumors. The presented optimization methods are based on semi-definite quadratic programming, yield provably globally optimal Halbach designs in 2 and 3-dimensions, for maximal pull or push magnetic forces (stronger pull forces can collect nano-particles against blood forces in deeper vessels; push forces can be used to inject particles into precise locations, e.g. into the inner ear). These Halbach designs, here tested in simulations of Maxwell's equations, significantly outperform benchmark magnets of the same size and strength. For example, a 3-dimensional 36 element 2000 cm(3) volume optimal Halbach design yields a ×5 greater force at a 10 cm depth compared to a uniformly magnetized magnet of the same size and strength. The designed arrays should be feasible to construct, as they have a similar strength (≤ 1 Tesla), size (≤ 2000 cm(3)), and number of elements (≤ 36) as previously demonstrated arrays, and retain good performance for reasonable manufacturing errors (element magnetization direction errors ≤ 5°), thus yielding practical designs to improve magnetic drug targeting treatment depths.

  1. Curvature contributions to the static electrical properties of push-pull molecules

    International Nuclear Information System (INIS)

    Squitieri, Emilio

    2005-01-01

    Calculations of the curvature contribution to the diagonals components of the static dipole moment (μ), polarizability (α), first (β) and second (γ) hyperpolarizability of push-pull molecules are presented. This contribution was obtained from the analytical evaluation of electrical properties method using the harmonic zero-point energy. The valence-bond charge-transfer model was employed to obtain the field-dependent force constant and their derivates with respect to electric field. Our results show a relationship between the curvature and electronic contributions. We have also found that the curvature contribution is important in a numerical estimation of β and γ

  2. The "Push-Pull" Approach to Fast-Track Management Development: A Case Study in Scientific Publishing

    Science.gov (United States)

    Fojt, Martin; Parkinson, Stephen; Peters, John; Sandelands, Eric

    2008-01-01

    Purpose: The purpose of this paper is to explore how a medium sized business has addressed what it has termed a "push-pull" method of management and organization development, based around an action learning approach. Design/methodology/approach: The paper sets out a methodology that other SMEs might look to replicate in their management and…

  3. Deep groundwater flow systems and their characterization in single-well settings by ''push-pull'' tracer tests

    International Nuclear Information System (INIS)

    Hebig-Schubert, Klaus

    2014-01-01

    This thesis demonstrates the growing importance of deep groundwater research and the increasing demand for the development of suitable single-well test methods. At the forefront of the research on groundwater in the deep underground, radioactive waste disposal in deep geological repositories, CO 2 storage, geothermal energy supply, and aquifer storage and recovery systems (ASR) are on the agenda. The developments of suitable methods for investigating these resources are a main target. Currently available methods show considerable limitations. Accordingly, comprehensive methods for the hydraulic and hydrochemical characterization of deeper aquifers with single-well access are needed. Therefore, the goal of this PhD thesis was to identify, test, and enhance potentially suitable single-well methods for characterization of groundwater flow and solute transport in such settings. For this, several Single-Well Injection-Withdrawal (''push-pull'') tracer tests were applied at the Hamasato field site (Horonobe, Japan) in a ∝100 m deep groundwater monitoring well. Aim was to characterize the impact of a dynamic saltwater-freshwater interface on a coastal aquifer. Based on the experiences of the first methodological test, a second field campaign was conducted. This campaign focused on a systematic evaluation of the push-pull tracer test method for the first time at all. The experiments focused on the investigation of the so-called ''chaser'' and its impact on the test results. The chaser is a specific part of many push-pull tracer tests setups. From these experiments, a specific test design for the investigation of the saltwater-freshwater interface in a single-well setting was developed. The application of this design on questions regarding different fluids within the same system, e.g. different mineralized fluids (saltwater-freshwater-interface, ASR) or temperatures (geothermal research), are promising future approaches for this

  4. Deep groundwater flow systems and their characterization in single-well settings by ''push-pull'' tracer tests

    Energy Technology Data Exchange (ETDEWEB)

    Hebig-Schubert, Klaus

    2014-11-21

    This thesis demonstrates the growing importance of deep groundwater research and the increasing demand for the development of suitable single-well test methods. At the forefront of the research on groundwater in the deep underground, radioactive waste disposal in deep geological repositories, CO{sub 2} storage, geothermal energy supply, and aquifer storage and recovery systems (ASR) are on the agenda. The developments of suitable methods for investigating these resources are a main target. Currently available methods show considerable limitations. Accordingly, comprehensive methods for the hydraulic and hydrochemical characterization of deeper aquifers with single-well access are needed. Therefore, the goal of this PhD thesis was to identify, test, and enhance potentially suitable single-well methods for characterization of groundwater flow and solute transport in such settings. For this, several Single-Well Injection-Withdrawal (''push-pull'') tracer tests were applied at the Hamasato field site (Horonobe, Japan) in a ∝100 m deep groundwater monitoring well. Aim was to characterize the impact of a dynamic saltwater-freshwater interface on a coastal aquifer. Based on the experiences of the first methodological test, a second field campaign was conducted. This campaign focused on a systematic evaluation of the push-pull tracer test method for the first time at all. The experiments focused on the investigation of the so-called ''chaser'' and its impact on the test results. The chaser is a specific part of many push-pull tracer tests setups. From these experiments, a specific test design for the investigation of the saltwater-freshwater interface in a single-well setting was developed. The application of this design on questions regarding different fluids within the same system, e.g. different mineralized fluids (saltwater-freshwater-interface, ASR) or temperatures (geothermal research), are promising future approaches for

  5. Range expansions transition from pulled to pushed waves with increasing cooperativity in an experimental microbial population

    Science.gov (United States)

    Gandhi, Saurabh; Yurtsev, Eugene; Korolev, Kirill; Gore, Jeff

    Range expansions are becoming more frequent due to environmental changes and rare long distance dispersal, often facilitated by anthropogenic activities. Simple models in theoretical ecology explain many emergent properties of range expansions, such as a constant expansion velocity, in terms of organism-level properties such as growth and dispersal rates. Testing these quantitative predictions in natural populations is difficult because of large environmental variability. Here, we used a controlled microbial model system to study range expansions of populations with and without intra-specific cooperativity. For non-cooperative growth, the expansion dynamics were dominated by population growth at the low-density front, which pulled the expansion forward. We found these expansions to be in close quantitative agreement with the classical theory of pulled waves by Fisher and Skellam, suitably adapted to our experimental system. However, as cooperativity increased, the expansions transitioned to being pushed, i.e. controlled by growth in the bulk as well as in the front. Although both pulled and pushed waves expand at a constant velocity and appear otherwise similar, their distinct dynamics leads to very different evolutionary consequences. Given the prevalence of cooperative growth in nature, understanding the effects of cooperativity is essential to managing invading species and understanding their evolution.

  6. Novel family of quasi-Z-source DC/DC converters derived from current-fed push-pull converters

    DEFF Research Database (Denmark)

    Chub, Andrii; Husev, Oleksandr; Vinnikov, Dmitri

    2014-01-01

    This paper is devoted to the step-up quasi-Z-source dc/dc push-pull converter family. The topologies in the family are derived from the isolated boost converter family by replacing input inductors with the quasi-Z-source network. Two new topologies are proposed, analyzed and compared. Theoretical...

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

    Science.gov (United States)

    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…

  8. ''Push-pull'' gastrostomy: a new technique for percutaneous gastrostomy tube insertion in the neonate and young infant

    International Nuclear Information System (INIS)

    Cahill, A.M.; Kaye, R.D.; Fitz, C.R.; Towbin, R.B.

    2001-01-01

    Objective. To evaluate a newly developed method combining antegrade and retrograde techniques for percutaneous gastrostomy tube (PGT) insertion in the neonate and young infant. Materials and methods. From January 1994 to December 2000, 85 children (47 male, 38 female), mean age 4.5 months (range 0.44-9.13 months) underwent PGT insertion using the ''push-pull'' technique. With the addition, 57 children had a jejunostomy tube placed as well at or within 24 h of the PGT procedure. The mean weight was 3.74 kg, range 1.5-7.0 kg. The indications for the procedure included failure to thrive in 40 patients (25 %), static encephalopathy in 21 (25 %), neurological/congenital abnormalities in 12 (14 %), aspiration in 7 (8 %), and cardiac problems in 5 (6 %). Results. Eighty-five PGTs were successfully inserted in 85 children. One procedure was initially unsuccessful due to failed conscious sedation and was completed under general anesthesia. Four of 85 patients initially had attempted antegrade placement that failed, and the procedure was successfully completed using the ''push-pull'' method. One major complication occurred: a gastrocolic fistula at day 5 post-procedure, which was surgically repaired without sequelae. Tube-related problems included; tube dislodgement (n = 1) and procedure-related stomal infection (n = 3). Conclusion. The ''push-pull'' gastrostomy technique is a safe, effective method of percutaneous gastrostomy tube placement in neonates. It facilitates successful placement of the PGT in patients in whom the classic antegrade method is not possible. It has become the procedure of choice in this group. (orig.)

  9. L4-L5 compression and anterior/posterior joint shear forces in cabin attendants during the initial push/pull actions of airplane meal carts

    DEFF Research Database (Denmark)

    Sandfeld, Jesper; Rosgaard, Christian; Jensen, Bente Rona

    2014-01-01

    The aim of the present study was to assess the acute low back load of cabin attendants during cart handling and to identify working situations which present the highest strain on the worker. In a setup, 17 cabin attendants (ten females and seven males) pushed, pulled and turned a 20kg standard meal...... was used to calculate the acute L4-L5 load. No working situations created loads greater than the accepted values for single exertions, however compression and anterior/posterior shear forces during pulling and turning were much higher when compared with pushing. There were significant effects of handling...... the cart on different floor types, at the varying inclinations and with different cart weights. Additionally, when external forces were reduced, the cabin attendants did not decrease push/pull force proportionally and thus the L4-L5 load did not decrease as much as expected....

  10. Gender differences in exerted forces and physiological load during pushing and pulling of wheeled cages by postal workers

    NARCIS (Netherlands)

    Van Der Beek, Allard J.; Kluver, B.D.R.; Frings-Dresen, M. H. W.; Hoozemans, M. J M

    The aim was to determine gender differences regarding exerted forces and physiological load during push/pull tasks simulating the daily working practice of postal workers. Eight female and four male workers handled four-wheeled cages under eight conditions corresponding to the cage weight (130, 250,

  11. Push-pull test: a method of evaluating formation adsorption parameters for predicting the environmental effects on in situ coal gasification and uranium recovery

    International Nuclear Information System (INIS)

    Drever, J.I.; McKee, C.R.

    1980-11-01

    The push-pull test, which is a simple injection and pumping sequence of groundwater spiked with solutes of interest, is presented as a method of determining the adsorption characteristics of a formation. Adsorption properties are necessary to predict restoration from both in situ coal gasification and in situ uranium extraction. The major problems in applying laboratory measurements to the field concern scaling the effect of particle size and obtaining representative samples. Laboratory measurements are conducted on gram to kilogram scale samples, whereas the push-pull test evaluates a sample weighing approximately 130 to 1000 metric tons, depending on volume injected and porosity. The problem in translating laboratory results to the field appear to be less severe for sedimentary uranium bodies than for coal. Laboratory measurements are useful in delineating ranges in adsorption properties and in planning the field experiment. Two field push-pull tests were conducted on uranium formations in Wyoming. Adsorption properties estimated from these tests on the basis of a simple cell model were compared to the laboratory values. In the first case, excellent agreement was observed between the values estimated from the field test and the values measured in the laboratory. In the second case, the value for K/sub d/ determined in the laboratory was five times higher than the field value. It is recommended that push-pull tests be conducted on coal formations being considered for in situ gasification in view of the great uncertainty in extrapolating laboratory adsorption properties to the field

  12. Design of band-pass push-pull stages of power amplifiers for UHF transmitters of FM and TV broadcasting

    OpenAIRE

    Titov, A. A.

    2005-01-01

    The paper considers principles of construction, peculiarities of design, and techniques of network element calculation of push-pull amplification stages in linear bipolar microwave transistors. An example of calculation and results of experimental tests of an amplifier for transmitters of FM and TV broadcasting are presented.

  13. Evaluation of a peridomestic mosquito trap for integration into an Aedes aegypti (Diptera: Culicidae) push-pull control strategy.

    Science.gov (United States)

    Salazar, Ferdinand V; Achee, Nicole L; Grieco, John P; Prabaripai, Atchariya; Eisen, Lars; Shah, Pankhil; Chareonviriyaphap, Theeraphap

    2012-06-01

    We determined the feasibility of using the BG-Sentinel™ mosquito trap (BGS) as the pull component in a push-pull strategy to reduce indoor biting by Aedes aegypti. This included evaluating varying numbers of traps (1-4) and mosquito release numbers (10, 25, 50, 100, 150, 200, and 250) on recapture rates under screen house conditions. Based on these variations in trap and mosquito numbers, release intervals were rotated through a completely randomized design with environmental factors (temperature, relative humidity, and light intensity) and monitored throughout each experiment. Data from four sampling time points (05:30, 09:30, 13:30, and 17:30) indicate a recapture range among treatments of 66-98%. Furthermore, 2-3 traps were as effective in recapturing mosquitoes as 4 traps for all mosquito release numbers. Time trends indicate Day 1 (the day the mosquitoes were released) as the "impact period" for recapture with peak numbers of marked mosquitoes collected at 09:30 or 4 h post-release. Information from this study will be used to guide the configuration of the BGS trap component of a push-pull vector control strategy currently in the proof-of-concept stage of development in Thailand and Peru. © 2012 The Society for Vector Ecology.

  14. Pulled Motzkin paths

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2010-01-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  15. Pulled Motzkin paths

    Energy Technology Data Exchange (ETDEWEB)

    Janse van Rensburg, E J, E-mail: rensburg@yorku.c [Department of Mathematics and Statistics, York University, Toronto, ON, M3J 1P3 (Canada)

    2010-08-20

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) {yields} f as f {yields} {infinity}, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) {yields} 2f as f {yields} {infinity}, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  16. Pulled Motzkin paths

    Science.gov (United States)

    Janse van Rensburg, E. J.

    2010-08-01

    In this paper the models of pulled Dyck paths in Janse van Rensburg (2010 J. Phys. A: Math. Theor. 43 215001) are generalized to pulled Motzkin path models. The generating functions of pulled Motzkin paths are determined in terms of series over trinomial coefficients and the elastic response of a Motzkin path pulled at its endpoint (see Orlandini and Whittington (2004 J. Phys. A: Math. Gen. 37 5305-14)) is shown to be R(f) = 0 for forces pushing the endpoint toward the adsorbing line and R(f) = f(1 + 2cosh f))/(2sinh f) → f as f → ∞, for forces pulling the path away from the X-axis. In addition, the elastic response of a Motzkin path pulled at its midpoint is shown to be R(f) = 0 for forces pushing the midpoint toward the adsorbing line and R(f) = f(1 + 2cosh (f/2))/sinh (f/2) → 2f as f → ∞, for forces pulling the path away from the X-axis. Formal combinatorial identities arising from pulled Motzkin path models are also presented. These identities are the generalization of combinatorial identities obtained in directed paths models to their natural trinomial counterparts.

  17. Optimal Halbach permanent magnet designs for maximally pulling and pushing nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sarwar, A., E-mail: azeem@umd.edu [Fischell Department of Bioengineering, College Park, MD (United States); University of Maryland at College Park (United States); Nemirovski, A. [H. Milton Stewart School of Industrial and Systems Engineering (ISyE), Georgia Institute of Technology (United States); Shapiro, B. [Fischell Department of Bioengineering, College Park, MD (United States); Institute for Systems Research (United States); University of Maryland at College Park (United States)

    2012-03-15

    Optimization methods are presented to design Halbach arrays to maximize the forces applied on magnetic nanoparticles at deep tissue locations. In magnetic drug targeting, where magnets are used to focus therapeutic nanoparticles to disease locations, the sharp fall off of magnetic fields and forces with distances from magnets has limited the depth of targeting. Creating stronger forces at a depth by optimally designed Halbach arrays would allow treatment of a wider class of patients, e.g. patients with deeper tumors. The presented optimization methods are based on semi-definite quadratic programming, yield provably globally optimal Halbach designs in 2 and 3-dimensions, for maximal pull or push magnetic forces (stronger pull forces can collect nanoparticles against blood forces in deeper vessels; push forces can be used to inject particles into precise locations, e.g. into the inner ear). These Halbach designs, here tested in simulations of Maxwell's equations, significantly outperform benchmark magnets of the same size and strength. For example, a 3-dimensional 36 element 2000 cm{sup 3} volume optimal Halbach design yields a 5 Multiplication-Sign greater force at a 10 cm depth compared to a uniformly magnetized magnet of the same size and strength. The designed arrays should be feasible to construct, as they have a similar strength ({<=}1 T), size ({<=}2000 cm{sup 3}), and number of elements ({<=}36) as previously demonstrated arrays, and retain good performance for reasonable manufacturing errors (element magnetization direction errors {<=}5 Degree-Sign), thus yielding practical designs to improve magnetic drug targeting treatment depths. - Highlights: Black-Right-Pointing-Pointer Optimization methods presented to design Halbach arrays for drug targeting. Black-Right-Pointing-Pointer The goal is to maximize forces on magnetic nanoparticles at deep tissue locations. Black-Right-Pointing-Pointer The presented methods yield provably globally optimal Halbach

  18. Optimal Halbach permanent magnet designs for maximally pulling and pushing nanoparticles

    International Nuclear Information System (INIS)

    Sarwar, A.; Nemirovski, A.; Shapiro, B.

    2012-01-01

    Optimization methods are presented to design Halbach arrays to maximize the forces applied on magnetic nanoparticles at deep tissue locations. In magnetic drug targeting, where magnets are used to focus therapeutic nanoparticles to disease locations, the sharp fall off of magnetic fields and forces with distances from magnets has limited the depth of targeting. Creating stronger forces at a depth by optimally designed Halbach arrays would allow treatment of a wider class of patients, e.g. patients with deeper tumors. The presented optimization methods are based on semi-definite quadratic programming, yield provably globally optimal Halbach designs in 2 and 3-dimensions, for maximal pull or push magnetic forces (stronger pull forces can collect nanoparticles against blood forces in deeper vessels; push forces can be used to inject particles into precise locations, e.g. into the inner ear). These Halbach designs, here tested in simulations of Maxwell's equations, significantly outperform benchmark magnets of the same size and strength. For example, a 3-dimensional 36 element 2000 cm 3 volume optimal Halbach design yields a 5× greater force at a 10 cm depth compared to a uniformly magnetized magnet of the same size and strength. The designed arrays should be feasible to construct, as they have a similar strength (≤1 T), size (≤2000 cm 3 ), and number of elements (≤36) as previously demonstrated arrays, and retain good performance for reasonable manufacturing errors (element magnetization direction errors ≤5°), thus yielding practical designs to improve magnetic drug targeting treatment depths. - Highlights: ► Optimization methods presented to design Halbach arrays for drug targeting. ► The goal is to maximize forces on magnetic nanoparticles at deep tissue locations. ► The presented methods yield provably globally optimal Halbach designs in 2D and 3D. ► These designs significantly outperform benchmark magnets of the same size and strength. ► These

  19. The 'push-pull' dosimeter: When two pigments are better than one

    International Nuclear Information System (INIS)

    Bosi, Stephen G; Baldock, Clive; Smee, Robert

    2010-01-01

    A new kind of gel dosimeter (the 'push-pull' dosimeter) is proposed which would contain two spectrally complementary pigments, one which darkens with increasing dose and another which bleaches. The bleaching pigment would be optimised for high sensitivity and the darkening pigment for low sensitivity. By employing dual pigments optimised independently, the usual requisite compromises between sensitivity at low dose and accuracy at high dose would be relaxed. Such a gel, after exposure would be read using two successive optical CT scans employing two different scan wavelengths. The use of dual pigments could also reduce the occurrence of regions of high optical attenuation which generate artefacts in optical CT. This paper also presents results of simulations of the behaviour of such a gel when scanned using optical cone beam CT.

  20. Generic, Extensible, Configurable Push-Pull Framework for Large-Scale Science Missions

    Science.gov (United States)

    Foster, Brian M.; Chang, Albert Y.; Freeborn, Dana J.; Crichton, Daniel J.; Woollard, David M.; Mattmann, Chris A.

    2011-01-01

    The push-pull framework was developed in hopes that an infrastructure would be created that could literally connect to any given remote site, and (given a set of restrictions) download files from that remote site based on those restrictions. The Cataloging and Archiving Service (CAS) has recently been re-architected and re-factored in its canonical services, including file management, workflow management, and resource management. Additionally, a generic CAS Crawling Framework was built based on motivation from Apache s open-source search engine project called Nutch. Nutch is an Apache effort to provide search engine services (akin to Google), including crawling, parsing, content analysis, and indexing. It has produced several stable software releases, and is currently used in production services at companies such as Yahoo, and at NASA's Planetary Data System. The CAS Crawling Framework supports many of the Nutch Crawler's generic services, including metadata extraction, crawling, and ingestion. However, one service that was not ported over from Nutch is a generic protocol layer service that allows the Nutch crawler to obtain content using protocol plug-ins that download content using implementations of remote protocols, such as HTTP, FTP, WinNT file system, HTTPS, etc. Such a generic protocol layer would greatly aid in the CAS Crawling Framework, as the layer would allow the framework to generically obtain content (i.e., data products) from remote sites using protocols such as FTP and others. Augmented with this capability, the Orbiting Carbon Observatory (OCO) and NPP (NPOESS Preparatory Project) Sounder PEATE (Product Evaluation and Analysis Tools Elements) would be provided with an infrastructure to support generic FTP-based pull access to remote data products, obviating the need for any specialized software outside of the context of their existing process control systems. This extensible configurable framework was created in Java, and allows the use of

  1. A new soft switched push pull current fed converter for fuel cell applications

    International Nuclear Information System (INIS)

    Delshad, Majid; Farzanehfard, Hosein

    2011-01-01

    In this paper a new zero voltage switching current fed push pull dc-dc converter is proposed for fuel cell generation system. The auxiliary circuit in this converter, not only absorbs the voltage surge across the switches at turn off instance, but also provides zero voltage switching condition for all converter switches. Therefore, the converter efficiency is increased and size and weight of the converter can be decreased. Also implementation of control circuit is very simple since the converter is PWM controlled. In this paper, the proposed dc-dc converter operating modes are analyzed and to verify the converter operation a laboratory prototype is implemented and the experimental results are presented.

  2. Ultrafine particle air pollution inside diesel-propelled passenger trains.

    Science.gov (United States)

    Abramesko, Victoria; Tartakovsky, Leonid

    2017-07-01

    Locomotives with diesel engines are used worldwide and are an important source of air pollution. Pollutant emissions by locomotive engines affect the air quality inside passenger trains. This study is aimed at investigating ultrafine particle (UFP) air pollution inside passenger trains and providing a basis for assessing passenger exposure to this pollutant. The concentrations of UFPs inside the carriages of push-pull trains are dramatically higher when the train operates in pull mode. This clearly shows that locomotive engine emissions are a dominant factor in train passengers' exposure to UFPs. The highest levels of UFP air pollution are observed inside the carriages of pull trains close to the locomotive. In push mode, the UFP number concentrations were lower by factors of 2.6-43 (depending on the carriage type) compared to pull mode. The UFP concentrations are substantially lower in diesel multiple-unit trains than in trains operating in pull mode. A significant influence of the train movement regime on the UFP NC inside a carriage is observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effects of push/pull perfusion and ultrasonication on the extraction efficiencies of phthalate esters in sports drink samples using on-line hollow-fiber liquid-phase microextraction.

    Science.gov (United States)

    Chao, Yu-Ying; Lee, Chien-Hung; Chien, Tzu-Yang; Shih, Yu-Hsuan; Lu, Yin-An; Kuo, Ting-Hsuan; Huang, Yeou-Lih

    2013-08-28

    In previous studies, we developed a process, on-line ultrasound-assisted push/pull perfusion hollow-fiber liquid-phase microextraction (UA-PPP-HF-LPME), combining the techniques of push/pull perfusion (PPP) and ultrasonication with hollow-fiber liquid-phase microextraction (HF-LPME), to achieve rapid extraction of acidic phenols from water samples. In this present study, we further evaluated three more-advanced and novel effects of PPP and ultrasonication on the extraction efficiencies of neutral high-molecular-weight phthalate esters (HPAEs) in sports drinks. First, we found that inner-fiber fluid leakage occurs only in push-only perfusion-based and pull-only perfusion-based HF-LPME, but not in the PPP mode. Second, we identified a significant negative interaction between ultrasonication and temperature. Third, we found that the extraction time of the newly proposed system could be shortened by more than 93%. From an investigation of the factors affecting UA-PPP-HF-LPME, we established optimal extraction conditions and achieved acceptable on-line enrichment factors of 92-146 for HPAEs with a sampling time of just 2 min.

  4. Eye Pull, Eye Push: Moving Objects between Large Screens and Personal Devices with Gaze and Touch

    OpenAIRE

    Turner , Jayson; Alexander , Jason; Bulling , Andreas; Schmidt , Dominik; Gellersen , Hans

    2013-01-01

    Part 4: Gaze-Enabled Interaction Design; International audience; Previous work has validated the eyes and mobile input as a viable approach for pointing at, and selecting out of reach objects. This work presents Eye Pull, Eye Push, a novel interaction concept for content transfer between public and personal devices using gaze and touch. We present three techniques that enable this interaction: Eye Cut & Paste, Eye Drag & Drop, and Eye Summon & Cast. We outline and discuss several scenarios in...

  5. Grip Force and 3D Push-Pull Force Estimation Based on sEMG and GRNN

    Directory of Open Access Journals (Sweden)

    Changcheng Wu

    2017-06-01

    Full Text Available The estimation of the grip force and the 3D push-pull force (push and pull force in the three dimension space from the electromyogram (EMG signal is of great importance in the dexterous control of the EMG prosthetic hand. In this paper, an action force estimation method which is based on the eight channels of the surface EMG (sEMG and the Generalized Regression Neural Network (GRNN is proposed to meet the requirements of the force control of the intelligent EMG prosthetic hand. Firstly, the experimental platform, the acquisition of the sEMG, the feature extraction of the sEMG and the construction of GRNN are described. Then, the multi-channels of the sEMG when the hand is moving are captured by the EMG sensors attached on eight different positions of the arm skin surface. Meanwhile, a grip force sensor and a three dimension force sensor are adopted to measure the output force of the human's hand. The characteristic matrix of the sEMG and the force signals are used to construct the GRNN. The mean absolute value and the root mean square of the estimation errors, the correlation coefficients between the actual force and the estimated force are employed to assess the accuracy of the estimation. Analysis of variance (ANOVA is also employed to test the difference of the force estimation. The experiments are implemented to verify the effectiveness of the proposed estimation method and the results show that the output force of the human's hand can be correctly estimated by using sEMG and GRNN method.

  6. L4-L5 compression and anterior/posterior joint shear forces in cabin attendants during the initial push/pull actions of airplane meal carts.

    Science.gov (United States)

    Sandfeld, Jesper; Rosgaard, Christian; Jensen, Bente Rona

    2014-07-01

    The aim of the present study was to assess the acute low back load of cabin attendants during cart handling and to identify working situations which present the highest strain on the worker. In a setup, 17 cabin attendants (ten females and seven males) pushed, pulled and turned a 20 kg standard meal cart (L: 0.5m × W: 0.3 m × H: 0.92 m) loaded with extra 20 kg and 40 kg, respectively on two different surfaces (carpet and linoleum) and at three floor inclinations (-2°, 0° and +2°). Two force transducers were mounted as handles. Two-dimensional movement analysis was performed and a 4D WATBAK modelling tool was used to calculate the acute L4-L5 load. No working situations created loads greater than the accepted values for single exertions, however compression and anterior/posterior shear forces during pulling and turning were much higher when compared with pushing. There were significant effects of handling the cart on different floor types, at the varying inclinations and with different cart weights. Additionally, when external forces were reduced, the cabin attendants did not decrease push/pull force proportionally and thus the L4-L5 load did not decrease as much as expected. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  7. Acceptor number-dependent ultrafast photo-physical properties of push-pull chromophores using time-resolved methods

    Science.gov (United States)

    Chi, Xiao-Chun; Wang, Ying-Hui; Gao, Yu; Sui, Ning; Zhang, Li-Quan; Wang, Wen-Yan; Lu, Ran; Ji, Wen-Yu; Yang, Yan-Qiang; Zhang, Han-Zhuang

    2018-04-01

    Three push-pull chromophores comprising a triphenylamine (TPA) as electron-donating moiety and functionalized β-diketones as electron acceptor units are studied by various spectroscopic techniques. The time-correlated single-photon counting data shows that increasing the number of electron acceptor units accelerates photoluminescence relaxation rate of compounds. Transient spectra data shows that intramolecular charge transfer (ICT) takes place from TPA units to β-diketones units after photo-excitation. Increasing the number of electron acceptor units would prolong the generation process of ICT state, and accelerate the excited molecule reorganization process and the relaxation process of ICT state.

  8. What Makes International Capital Flows So Volatile?: Push vs. Pull Factors in the Case of Korea

    Directory of Open Access Journals (Sweden)

    Tae-Joon Kim

    2010-12-01

    Full Text Available This paper analyzes the determinants of financial capital flows in Korea, which provides an intriguing case for examining the volatility of such flows as an almost fully opened capital market. Our empirical analysis finds both pull and push factors have significantly affected all three types of foreign capital flows- foreign equity investment, foreign bond investment and foreign other-type investment- in Korea, though the relative importance of each factor varies by sample period and type of financial capital. First, the determinants of capital inflows changed substantially following the 1997 currency crisis. The impact of push factors on foreign investment strengthened, rendering the Korean stock and bond market more susceptible to external shocks. Second, the global financial crisis, which increased global financial instability and preference for safe assets, appears to have had a negative effect on other-type investment. However, fThis paper analyzes the determinants of financial capital flows in Korea, which provides an intriguing case for examining the volatility of such flows as an almost fully opened capital market. Our empirical analysis finds both pull and push factors have significantly affected all three types of foreign capital flows- foreign equity investment, foreign bond investment and foreign other-type investment- in Korea, though the relative importance of each factor varies by sample period and type of financial capital. First, the determinants of capital inflows changed substantially following the 1997 currency crisis. The impact of push factors on foreign investment strengthened, rendering the Korean stock and bond market more susceptible to external shocks. Second, the global financial crisis, which increased global financial instability and preference for safe assets, appears to have had a negative effect on other-type investment. However, foreign equity investment showed a quick recovery in the wake of global financial

  9. A comparison of push and pull production controls under machine breakdown

    Directory of Open Access Journals (Sweden)

    Prakash, J.

    2011-01-01

    Full Text Available Production control for high-mix production remains a complex issue. Common pull system replenishment generates large works-in-process (WIPs for each part type, especially under breakdown. This paper attempts to solve this by presenting a production control that classifies parts into two categories. The performances of three production control mechanisms under breakdown are compared. The production control mechanisms in consideration are push, shared constant WIP (CONWIP, and parallel CONWIP. A full-factorial simulation experiment was conducted. ANOVA was performed to determine the significant effects of input factors. Response surface methodology was used to demonstrate the behavior of performance measures in terms of these significant input factors. The results prove that parallel CONWIP is superior over shared CONWIP in terms of the average flow time per part. If categorical dispatch rules are employed, parallel CONWIP outperforms shared CONWIP in terms of service level. With high card count, parallel CONWIP generally produces lower bottleneck utilizations while maintaining a low average flow time per part than shared CONWIP.

  10. Characterization and Performance Comparison of Low-Voltage, High-Speed, Push-Pull and Traveling-Wave Silicon Mach-Zehnder Modulators

    Science.gov (United States)

    2014-03-27

    unloaded transmission line is simply the coplanar strip waveguide (CPS), and is designed to have an impedance higher than 50Ω, as the capacitive load...microwave loss operation, with a junction capacitance of 0.41 fF at 0 V bias. From a macroscopic point of view, the push-pull design uses two electrodes...by ±5°. The chip mount is designed to hold a thermoelectric cooler (TEC) between two copper plates, and a temperature sensor in the top plate, above

  11. Determinants of FDI into Central and Eastern European Countries: Pull or Push Effect?

    Directory of Open Access Journals (Sweden)

    Burcak Polat

    2015-11-01

    Full Text Available Despite the growing interest in foreign direct investments (FDI, substantial uncertainty still exists regarding what stimulates foreign investors to operate in a foreign market and uneven distribution of FDI across countries. Using panel data for 2001 -2012 period, the major determinants of the FDI inflows into the Central and Eastern European Countries are analysed in this study. Strong evidence are found that while EU CR indices, EU and USA real GDP growth rates and global financial crisis have power to explain FDI inflows among all other push factors, labour cost, electricity price, real exchange rate and host CR indices have strong influential on FDI as the most effective pull factors. However, study fails to find any effect of openness, tax rates on commercial profits, USA CR indices, interest rate differentials and host real GDP growth on FDI.

  12. Novel push-pull fluorescent dyes - 7-(diethylamino)furo- and thieno[3,2-c]coumarins derivatives: structure, electronic spectra and TD-DFT study

    Science.gov (United States)

    Akchurin, Igor O.; Yakhutina, Anna I.; Bochkov, Andrei Y.; Solovjova, Natalya P.; Medvedev, Michael G.; Traven, Valerii F.

    2018-05-01

    Novel push-pull fluorescent dyes - 7-(diethylamino)furo- and 7-(diethylamino)thieno[3,2-c]coumarins derivatives have been synthesized using formyl derivatives of furo- and thieno[3,2-c]coumarins as starting materials. Electron absorption and fluorescent spectra of the dyes have been recorded in different solvents. Structure and solvent effects on the dyes spectral characteristics were analyzed. The fusion of five-membered heterocycle to coumarin provides a definite increase of Stokes shifts in all solvents and results in higher quantum yields of fluorescence. The absorption and emission bands of thieno[3,2-c] coumarin derivatives are definitely shifted to the red region (3-30 nm) compared to similar derivatives of furo[3,2-c]coumarin. TD-DFT calculations of some of the studied compounds have shown that hybrid DFT functionals and adequate representation of molecular environment are essential for obtaining accurate UV-Vis absorption spectra for the dyes with extended π-system. The longest-wave electron transitions in the studied compounds were computationally shown to be of push-pull nature.

  13. Pushed, pulled, or blocked? The elderly and the labor market in post-Soviet Russia.

    Science.gov (United States)

    Gerber, Theodore P; Radl, Jonas

    2014-05-01

    Russia provides an interesting context for studying the labor market experiences of the elderly because of its experience with market transition, its looming growth in the elderly dependency ratio, and its unusual pension policies that do not penalize pensioners for working. We use data from twenty surveys of the Russian population conducted from February 1991 to November 2007 to analyze the labor market participation and earnings of elderly Russians following market transition. Economic desperation, exacerbated by low pension levels, pushed some elderly to seek employment for income on the labor market. Elderly Russians with more education had more opportunities to work, and education differentials increased as market reforms progressed. The correlates of earnings operate similarly for retirement- and pre-retirement age Russians, with several exceptions: unobserved factors favoring employment are negatively associated with earnings for the elderly, occupation mediates most of the effects of education, and patterns of change over time differ somewhat. Elderly Russians are not disproportionately blocked from employment following market reforms. Following the initial transition shock, their labor market activity increased. Overall, both push and pull factors shape the employment and earnings of the elderly, affecting different segments of them. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. International migration of health professionals and the marketization and privatization of health education in India: from push-pull to global political economy.

    Science.gov (United States)

    Walton-Roberts, Margaret

    2015-01-01

    Health worker migration theories have tended to focus on labour market conditions as principal push or pull factors. The role of education systems in producing internationally oriented health workers has been less explored. In place of the traditional conceptual approaches to understanding health worker, especially nurse, migration, I advocate global political economy (GPE) as a perspective that can highlight how educational investment and global migration tendencies are increasing interlinked. The Indian case illustrates the globally oriented nature of health care training, and informs a broader understanding of both the process of health worker migration, and how it reflects wider marketization tendencies evident in India's education and health systems. The Indian case also demonstrates how the global orientation of education systems in source regions is increasingly central to comprehending the place of health workers in the global and Asian rise in migration. The paper concludes that Indian corporate health care training systems are increasingly aligned with the production of professionals orientated to globally integrated health human resource labour markets, and our conceptual analysis of such processes must effectively reflect these tendencies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. The United States and international climate cooperation: International 'pull' versus domestic 'push'

    International Nuclear Information System (INIS)

    Bang, Guri; Froyn, Camilla Bretteville; Hovi, Jon; Menz, Fredric C.

    2007-01-01

    The US government is being pressured by both international and domestic influences to re-engage in international climate control. This paper considers whether the international 'pull' and the domestic 'push' will be strong enough to accomplish this. First, we discuss whether changes in the architecture of the current climate regime might induce the United States to re-engage at the international level. We argue that the United States is unlikely to rejoin any global climate regime that is based on the Kyoto architecture, even if Kyoto were to be 'reformed'. Second, we discuss whether domestic political developments might eventually cause the United States to re-engage. We conclude that US re-engagement is likely to require the emergence of a new climate regime that basically extends US regulation to other countries. However, the forging of a unified US climate policy is still in the making. Furthermore, a new regime can gain widespread participation only if the Kyoto countries accept the idea of replacing Kyoto with some alternative architecture, which seems unlikely in the near future

  16. The United States and international climate cooperation: international ''pull'' versus domestic ''push''

    International Nuclear Information System (INIS)

    Bang, G.; Froyn, C.B.; Hovi, J.; Menz, F.C.; Clarkson University, Potsdam, NY

    2007-01-01

    The US government is being pressured by both international and domestic influences to re-engage in international climate control. This paper considers whether the international ''pull'' and the domestic ''push'' will be strong enough to accomplish this. First, we discuss whether changes in the architecture of the current climate regime might induce the United States to re-engage at the international level. We argue that the United States is unlikely to rejoin any global climate regime that is based on the Kyoto architecture, even if Kyoto were to be ''reformed''. Second, we discuss whether domestic political developments might eventually cause the United States to re-engage. We conclude that US re-engagement is likely to require the emergence of a new climate regime that basically extends US regulation to other countries. However, the forging of a unified US climate policy is still in the making. Furthermore, a new regime can gain widespread participation only if the Kyoto countries accept the idea of replacing Kyoto with some alternative architecture, which seems unlikely in the near future. (author)

  17. A Push-pull Protocol to Reduce Colonization of Bird Nest Boxes by Honey Bees.

    Science.gov (United States)

    Efstathion, Caroline A; Kern, William H

    2016-09-04

    Introduction of the invasive Africanized honey bee (AHB) into the Neotropics is a serious problem for many cavity nesting birds, specifically parrots. These bees select cavities that are suitable nest sites for birds, resulting in competition. The difficulty of removing bees and their defensive behavior makes a prevention protocol necessary. Here, we describe a push-pull integrated pest management protocol to deter bees from inhabiting bird boxes by applying a bird safe insecticide, permethrin, to repel bees from nest boxes, while simultaneously attracting them to pheromone-baited swarm traps. Shown here is an example experiment using Barn Owl nest boxes. This protocol successfully reduced colonization of Barn Owl nest boxes by Africanized honey bees. This protocol is flexible, allowing adjustments to accommodate a wide range of bird species and habitats. This protocol could benefit conservation efforts where AHB are located.

  18. Organization and intramolecular charge-transfer enhancement in tripodal tris[(pyridine-4-yl)phenyl]amine push-pull molecules by intercalation into layered materials bearing acidic functionalities

    Czech Academy of Sciences Publication Activity Database

    Melánová, Klára; Cvejn, D.; Bureš, F.; Zima, Vítězslav; Svoboda, Jan; Beneš, L.; Mikysek, T.; Pytela, O.; Knotek, P.

    2014-01-01

    Roč. 43, č. 27 (2014), s. 10462-10470 ISSN 1477-9226 R&D Projects: GA ČR(CZ) GA13-01061S Institutional support: RVO:61389013 Keywords : tripodal push-pull molecules * intercalation * zirconium hydrogenphosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 4.197, year: 2014

  19. Impact of the Anchoring Ligand on Electron Injection and Recombination Dynamics at the Interface of Novel Asymmetric Push-Pull Zinc Phthalocyanines and TiO2

    NARCIS (Netherlands)

    Sharma, Divya; Steen, Gerrit Willem; Korterik, Jeroen P.; Garcia-Iglesias, M.; Vazquez, P; Torres, T.; Herek, Jennifer Lynn; Huijser, Jannetje Maria

    2013-01-01

    Phthalocyanines are promising photosensitizers for dye-sensitized solar cells (DSSCs). A parameter that has been problematic for a long time involves electron injection (EI) into the TiO2. The development of push-pull phthalocyanines shows great potential to improve the ratio of EI to back electron

  20. Uranium metalla-allenes with carbene imido R_2C=U"I"V=NR' units (R=Ph_2PNSiMe_3; R'=CPh_3): alkali-metal-mediated push-pull effects with an amido auxiliary

    International Nuclear Information System (INIS)

    Lu, Erli; Tuna, Floriana; Kaltsoyannis, Nikolas; Liddle, Stephen T.; Lewis, William

    2016-01-01

    We report uranium(IV)-carbene-imido-amide metalla-allene complexes [U(BIPM"T"M"S)(NCPh_3)(NHCPh_3)(M)] (BIPM"T"M"S=C(PPh_2NSiMe_3)_2; M=Li or K) that can be described as R_2C=U=NR' push-pull metalla-allene units, as organometallic counterparts of the well-known push-pull organic allenes. The solid-state structures reveal that the R_2C=U=NR' units adopt highly unusual cis-arrangements, which are also reproduced by gas-phase theoretical studies conducted without the alkali metals to remove their potential structure-directing roles. Computational studies confirm the double-bond nature of the U=NR' and U=CR_2 interactions, the latter increasingly attenuated by potassium then lithium when compared to the hypothetical alkali-metal-free anion. Combined experimental and theoretical data show that the push-pull effect induced by the alkali metal cations and amide auxiliary gives a fundamental and tunable structural influence over the C=U"I"V=N units. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Push-pull with recovery stage high-voltage DC converter for PV solar generator

    Science.gov (United States)

    Nguyen, The Vinh; Aillerie, Michel; Petit, Pierre; Pham, Hong Thang; Vo, Thành Vinh

    2017-02-01

    A lot of systems are basically developed on DC-DC or DC-AC converters including electronic switches such as MOS or bipolar transistors. The limits of efficiency are quickly reached when high output voltages and high input currents are needed. This work presents a new high-efficiency-high-step-up based on push-pull DC-DC converter integrating recovery stages dedicated to smart HVDC distributed architecture in PV solar energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. Thus, the efficiency of a basic DC-HVDC converter dedicated to renewable energy production can be further improved with such topology. A prototype converter is developed, and experimentally tested for validation.

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

    Science.gov (United States)

    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.

  3. Push-pull converter with energy saving circuit for protecting switching transistors from peak power stress

    Science.gov (United States)

    Mclyman, W. T. (Inventor)

    1981-01-01

    In a push-pull converter, switching transistors are protected from peak power stresses by a separate snubber circuit in parallel with each comprising a capacitor and an inductor in series, and a diode in parallel with the inductor. The diode is connected to conduct current of the same polarity as the base-emitter juction of the transistor so that energy stored in the capacitor while the transistor is switched off, to protect it against peak power stress, discharges through the inductor when the transistor is turned on, and after the capacitor is discharges through the diode. To return this energy to the power supply, or to utilize this energy in some external circuit, the inductor may be replaced by a transformer having its secondary winding connected to the power supply or to the external circuit.

  4. Simultaneously 'pushing' and 'pulling' graphene oxide into low-polar solvents through a designed interface.

    Science.gov (United States)

    Liu, Zhen; Liu, Jingquan; Wang, Yichao; Razal, Joselito M; Francis, Paul S; Biggs, Mark J; Barrow, Colin J; Yang, Wenrong

    2018-08-03

    Dispersing graphene oxide (GO) in low-polar solvents can realize a perfect self-assembly with functional molecules and application in removal of organic impurities that only dissolve in low-polar solvents. The surface chemistry of GO plays an important role in its dispersity in these solvents. The direct transfer of hydrophilic GO into low-polar solvents, however, has remained an experimental challenge. In this study, we design an interface to transfer GO by simultaneously 'pushing and pulling' the nanosheets into low-polar solvents. Our approach is outstanding due to the ability to obtain monolayers of chemically reduced GO (CRGO) with designed surface properties in the organic phase. Using the transferred GO or CRGO dispersions, we have fabricated GO/fullerene nanocomposites and assessed the ability of CRGOs for dye adsorption. We hope our work can provide a universal approach for the phase transfer of other nanomaterials.

  5. Functional Requirements on the Design of the Detectors and the Interaction Region of an e+e- Linear Collider with a Push-Pull Arrangement of Detectors

    International Nuclear Information System (INIS)

    Markiewicz, T.

    2009-01-01

    The Interaction Region of the International Linear Collider is based on two experimental detectors working in a push-pull mode. A time efficient implementation of this model sets specific requirements and challenges for many detector and machine systems, in particular the IR magnets, the cryogenics and the alignment system, the beamline shielding, the detector design and the overall integration. This paper attempts to separate the functional requirements of a push pull interaction region and machine detector interface from any particular conceptual or technical solution that might have been proposed to date by either the ILC Beam Delivery Group or any of the three detector concepts. As such, we hope that it provides a set of ground rules for interpreting and evaluating the MDI parts of the proposed detector concept's Letters of Intent, due March 2009. The authors of the present paper are the leaders of the IR Integration Working Group within Global Design Effort Beam Delivery System and the representatives from each detector concept submitting the Letters Of Intent.

  6. Synthesis and pH-sensing Properties of a Push-Pull Conjugated Fluorophore Based on Dicyanomethylene-1,4-dihydropyridine

    International Nuclear Information System (INIS)

    Kim, Young Hyun; Kim, Heemoon; Kim, Hyung Jin

    2016-01-01

    A push-pull conjugated dye with a dicyanomethylene-1,4-dihydropyridine moiety (DCMP) was designed and synthesized for use as an optical pH sensor in acidic solution. The spectroscopic and pH-sensing properties of DCMP were investigated by UV-vis and fluorescence spectroscopy. DCMP displayed a pH-dependent ratiometric absorption property in the range of pH 4.5-12.0. The fluorescence intensity of DCMP around 560 nm, when irradiated at 435 nm, increased when pH was increased in the range of 2.0-7.0, showing a linear response in the pH range of 3.85-6.25.

  7. Next-Practise in University Research Based Open Innovation - From Push to Pull: Case Studies from Denmark

    DEFF Research Database (Denmark)

    Rønnow Lønholdt, Jens; Wilken Bengtsson, Mille; Karlby, Lone Tolstrup

    2013-01-01

    -graduate education at DTU in design and management of projects in network. It supports competence development within efficient knowledge transfer. Finally conclusions and recommendations will be presented and discussed based on the above six cases within university research based knowledge transfer. © Springer......How do we ensure knowledge transfer from universities in the most effective and efficient way? What is the right balance between a push and a pull approach? These issues have been discussed at length and various methods of intermediary facilitating and ways to organise the transfer have been tried...... in different contextual settings at universities all over the world. Lessons learned are mixed and naturally varies from country to country. This paper presents a recently completed development project concerning the transfer facility at the Technical University of Denmark (DTU). The project focused...

  8. Assessment of a Geothermal Doublet in the Malm Aquifer Using a Push-Pull Tracer Test

    Science.gov (United States)

    Lafogler, Mark; Somogyi, Gabriella; Nießner, Reinhard; Baumann, Thomas

    2013-04-01

    Geothermal exploration of the Malm aquifer in Bavaria is highly successful. Data about the long-term operation, however, is still scarce, although detailed knowledge about the processes occurring in the aquifer is a key requirement to run geothermal facilities efficiently and economically. While there usually is a constant flow of data from the production well (temperatures, hydraulic data, hydrochemical conditions, gas composition) not even the temperatures in the immediate surrounding of the reinjection well are accessible or known. In 2011 the geothermal facility in Pullach was extended with a third geothermal well reaching into the Malm aquifer which is now used as a reinjection well. The former reinjection well was converted to a production well after 5 years of operation. This setting offers a unique opportunity to study the processes in the vicinity of a reinjection well and provides the data base to describe the hydraulic, thermal and hydrochemical performance of the reservoir. The viscosity of the reinjected cold water is increasing by 60% compared to the production well, thus one would expect an increase of the reinjection pressure as the cold water plume spreads around the reinjection well. Measurements, however, show a significant decrease of the reinjection pressure, suggesting processes in the aquifer which positively change the hydraulic properties and overcompensate the viscosity effects. Hydrochemical data and modeling indicate that a dissolution of the matrix along the flow pathways is responsible for the decreasing reinjection pressures. The change of the flow direction from reinjection to production was used to conduct a push-pull tracer test. Here, a series of fluorescent dye pulses was added to the reinjected water before the former reinjection well was shut down (push phase). These tracers included a conservative tracer (Fluorescein), surface-sensitive tracers (Eosin/Sulforhodamin B), and a NAPL-sensitive tracer (Na-Naphthionate). After

  9. Voltage inverter with push-pull topology to inject energy into electrical systems with modulation SPWM

    Directory of Open Access Journals (Sweden)

    Emerson Charles M. Silva

    2013-09-01

    Full Text Available This paper presents a proposal for a voltage inverter topology based on push-pull converters, switched at high frequency to inject energy into the grid from a source of DC power. A system using two reverse voltage static converters provides the power grid; energy in the form of alternating current, that can work in conjunction with the provision of utility power. Aiming at the possible use of renewable energy sources, that can be stored in the form of voltage continuous, such as wind, solar, hydroelectric and others. The functioning of topology is presented, such as the power and control circuits, as well as sizing components, theoretical and practical results achieved with the assembly of a prototype 100W of power and switching in 40khz, which after filtering provides the frequency of 60Hz, which is compatible with the Brazilian electrical system.

  10. Solvent-Dependent Dual Fluorescence of the Push-Pull System 2-Diethylamino-7-Nitrofluorene

    KAUST Repository

    Larsen, Martin A. B.

    2018-01-31

    The solvent-dependent excited state behavior of the molecular push-pull system 2-diethylamino-7-nitrofluorene has been explored using femtosecond transient absorption spectroscopy in combination with density functional theory calculations. Several excited state minima have been identified computationally, all possessing significant intramolecular charge transfer character. The experimentally observed dual fluorescence is suggested to arise from a planar excited state minimum and another minimum reached by twisting of the aryl-nitrogen bond of the amino group. The majority of the excited state population, however, undergo non-radiative transitions and potential excited deactivation pathways are assessed in the computational investigation. A third excited state conformer, characterized by twisting around the aryl-nitrogen bond of the nitro group, is reasoned to be responsible for the majority of the non-radiative decays and a crossing between the excited state and ground state is localized. Additionally, ultrafast intersystem crossing is observed in the apolar solvent cyclohexane and rationalized to occur via an El-Sayed assisted transition from one of the identified excited state minima. The solvent thus determines more than just the fluorescence lifetime and shapes the potential energy landscape, thereby dictating the available excited state pathways.

  11. Solvent-Dependent Dual Fluorescence of the Push-Pull System 2-Diethylamino-7-Nitrofluorene

    KAUST Repository

    Larsen, Martin A. B.; Stephansen, Anne B.; Alarousu, Erkki; Pittelkow, Michael; Mohammed, Omar F.; Sø lling, Theis I

    2018-01-01

    The solvent-dependent excited state behavior of the molecular push-pull system 2-diethylamino-7-nitrofluorene has been explored using femtosecond transient absorption spectroscopy in combination with density functional theory calculations. Several excited state minima have been identified computationally, all possessing significant intramolecular charge transfer character. The experimentally observed dual fluorescence is suggested to arise from a planar excited state minimum and another minimum reached by twisting of the aryl-nitrogen bond of the amino group. The majority of the excited state population, however, undergo non-radiative transitions and potential excited deactivation pathways are assessed in the computational investigation. A third excited state conformer, characterized by twisting around the aryl-nitrogen bond of the nitro group, is reasoned to be responsible for the majority of the non-radiative decays and a crossing between the excited state and ground state is localized. Additionally, ultrafast intersystem crossing is observed in the apolar solvent cyclohexane and rationalized to occur via an El-Sayed assisted transition from one of the identified excited state minima. The solvent thus determines more than just the fluorescence lifetime and shapes the potential energy landscape, thereby dictating the available excited state pathways.

  12. "Pull and push back" concepts of longevity and life span extension.

    Science.gov (United States)

    Muradian, Khachik

    2013-12-01

    The negative relation between metabolism and life span is a fundamental gerontological discovery well documented in a variety of ontogenetic and phylogenetic models. But how the long-lived species and populations sustain lower metabolic rate and, in more general terms, what is the efficient way to decline the metabolism? The suggested 'pull and push back' hypothesis assumes that decreased Po2 (hypoxia) and/or increased [Formula: see text] (hypercapnia) may create preconditions for the declined metabolic and aging rates. However, wider implementation of such ideas is compromised because of little advances in modification of the metabolic rate. Artificial atmosphere with controlled [Formula: see text] and [Formula: see text] could be a promising approach because of the minimal external invasions and involvement of the backward and forward loops ensuring physiological self-regulation of the metabolic perturbations. General considerations and existing data indicate that manipulations of [Formula: see text] may be more efficient in life span extension than [Formula: see text]. Thus, maximum life span of mammals positively correlates with the blood [Formula: see text] and HCO3 (-) but not with [Formula: see text]. Yet, proportional decease of the body [Formula: see text] and increase of [Formula: see text] seems the most optimal regime ensuring lower losses of the energy equivalents. Furthermore, especially rewarding results could be expected when such changes are modeled without major external invasions using the animals' inner capacity to consume O2 and generate CO2, as it is typical for the extreme longevity.

  13. Non-paraxial beam to push and pull microparticles

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Qiu, C.-W.

    2011-01-01

    We discuss a feasibility of the pulling (backward) force acting on a spherical microparticle in a non-paraxial Bessel beam. The effect can be explained by the strong interaction of particle's multipoles or by the conservation of momentum in the system “photons-particle.” It is remarkable that the...

  14. Effects of Bulky Substituents of Push-Pull Porphyrins on Photovoltaic Properties of Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Higashino, Tomohiro; Kawamoto, Kyosuke; Sugiura, Kenichi; Fujimori, Yamato; Tsuji, Yukihiro; Kurotobi, Kei; Ito, Seigo; Imahori, Hiroshi

    2016-06-22

    To evaluate the effects of substituent bulkiness around a porphyrin core on the photovoltaic properties of porphyrin-sensitized solar cells, long alkoxy groups were introduced at the meso-phenyl group (ZnPBAT-o-C8) and the anchoring group (ZnPBAT-o-C8Cn, n = 4, 8) of an asymmetrically substituted push-pull porphyrin with double electron-donating diarylamino groups and a single electron-withdrawing carboxyphenylethynyl anchoring group. The spectroscopic and electrochemical properties of ZnPBAT-o-C8 and ZnPBAT-o-C8Cn were found to be superior to those of a push-pull porphyrin reference (YD2-o-C8), demonstrating their excellent light-harvesting and redox properties for dye-sensitized solar cells. A power conversion efficiency (η) of the ZnPBAT-o-C8-sensitized solar cell (η = 9.1%) is higher than that of the YD2-o-C8-sensitized solar cell (η = 8.6%) using iodine-based electrolyte due to the enhanced light-harvesting ability of ZnPBAT-o-C8. In contrast, the solar cells based on ZnPBAT-o-C8Cn, possessing the additional alkoxy chains in the anchoring group, revealed the lower η values of 7.3% (n = 4) and 7.0% (n = 8). Although ZnPBAT-o-C8Cn exhibited higher resistance at the TiO2-dye-electrolyte interface by virtue of the extra alkoxy chains, the reduced amount of the porphyrins on TiO2 by excessive addition of coadsorbent chenodeoxycholic acid (CDCA) for mitigating the aggregation on TiO2 resulted in the low η values. Meanwhile, the ZnPBAT-o-C8-sensitized solar cell showed the lower η value of 8.1% than the YD2-o-C8-sensitized solar cell (η = 9.8%) using cobalt-based electrolyte. The smaller η value of the ZnPBAT-o-C8-sensitized solar cell may be attributed to the insufficient blocking effect of the bulky substituents of ZnPBAT-o-C8 under the cobalt-based electrolyte conditions. Overall, the alkoxy chain length and substitution position around the porphyrin core are important factors to affect the cell performance.

  15. The limited role of aquifer heterogeneity on metal reduction in an Atlantic coastal plain determined by push-pull tests

    International Nuclear Information System (INIS)

    Mailloux, Brian J.; Devlin, Stephanie; Fuller, Mark E.; Onstott, T.C.; De Flaun, Mary F.; Choi, K.-H.; Green-Blum, Maria; Swift, Donald J.P.; McCarthy, John; Dong Hailiang

    2007-01-01

    Sixty push-pull experiments were conducted to determine the factors controlling Fe(III) and Mn(IV) reduction in a well-characterized, shallow, coastal plain aquifer near Oyster, VA, USA. The five multi-level samplers each equipped with 12 ports sampled a heterogeneous portion of the aquifer from 4.4 to 8m-bgs. Each multi-level sampler (MLS) was injected with groundwater that contained NO 3 - and Br - along with: (1) just groundwater (control treatment), (2) humics, (3) lactate (conducted twice) and (4) lactate plus humics. Microbially mediated Fe(III) reduction caused the aqueous Fe Tot concentrations to increase at every depth in the lactate treatment with significant increases within 1 day even while NO 3 - was present. Little change in the Fe Tot concentrations were observed in the control and humics treatment. Humics may have acted as an electron shuttle to increase Fe(III) reduction in the lactate plus humics treatment. The amount of Mn(IV) reduction was significantly lower than that of Fe(III) reduction. Geochemical modeling indicated that gas formation, sorption on reactive surfaces, and mineral precipitation were important processes and that Fe(III) and SO 4 2- reduction were co-occurring. Conditions were favorable for the precipitation of Fe-carbonates, Fe-sulfides and Fe-silicates. In the lactate treatment protist concentrations increased then decreased and planktonic cell concentrations steadily increased, whereas no change was observed in the control treatment. Correlations of Fe(III) reduction with physical and chemical heterogeneity were weak, probably as a result of the abundance of Fe(III) bearing minerals relative to electron donor abundance and that the push-pull test sampled a representative elemental volume that encompassed the microbial diversity within the aquifer. This work indicates that stimulating metal reduction in aquifer systems is a feasible method for remediating heterogeneous subsurface sites contaminated with metals and

  16. Pushed news: when the news comes to the cellphone

    Directory of Open Access Journals (Sweden)

    Antonio Fidalgo

    2009-12-01

    Full Text Available Combining two findings of recent surveys on the Internet which state that 1 “the Internet will soon surpass all other media as a main source for national and international news” and 2 “the mobile device will be the primary connection tool to the Internet in 2020” leads us to the conclusion that smartphones will soon be the primary source for news access. But if so, how will news come to the Internetconnected cellphones? In accordance with the distinction, already drawn in 1997, between push and pull technologies as two different forms of how content is delivered to the end users, cellphones are characterized as push devices (passive reception, in opposition to computers, classified as pull devices (active reception. The news items that fit cellphones are pushed news. And they will be pushed as SMS, e-mails, tweets and through news aggregators.

  17. PUSHED NEWS: When the news comes to the cellphone

    Directory of Open Access Journals (Sweden)

    Antonio Fidalgo

    2009-12-01

    Full Text Available Combining two findings of recent surveys on the Internet whichstate that 1 “the Internet will soon surpass all other media as a main source for national and international news” and 2 “the mobile device will be the primary connection tool to the Internet in 2020” leads us to the conclusion that smartphones will soon be the primary source for news access. But if so, how will news come to the Internetconnected cellphones? In accordance with the distinction, already drawn in 1997, between push and pull technologies as two different forms of how content is delivered to the end users, cellphones are characterized as push devices (passive reception, in opposition to computers, classified as pull devices (active reception. The news items that fit cellphones are pushed news. And they will be pushed as SMS, e-mails, tweets and through news aggregators.

  18. Mind-muscle connection training principle: influence of muscle strength and training experience during a pushing movement.

    Science.gov (United States)

    Calatayud, Joaquin; Vinstrup, Jonas; Jakobsen, Markus D; Sundstrup, Emil; Colado, Juan Carlos; Andersen, Lars L

    2017-07-01

    To investigate the effect of different attentional focus conditions on muscle activity during the push-up exercise and to assess the possible influence of muscle strength and training experience. Eighteen resistance-trained men performed 1RM bench press testing and were familiarized with the procedure during the first session. In the second session, three different conditions were randomly performed: regular push-up and push-up focusing on using the pectoralis major and triceps brachii muscles, respectively. Surface electromyography (EMG) was recorded and analyzed (EMG normalized to max; nEMG) for the triceps brachii and pectoralis major muscles. Participants had on average 8 (SD 6) years of training experience and 1RM of 1.25 (SD 0.28) kg per kg bodyweight. Focusing on using pectoralis major increased activity in this muscle by 9% nEMG (95% CI 5-13; Cohen's d 0.60) compared with the regular condition. Triceps activity was not significantly influenced by triceps focus although borderline significant, with a mean difference of 5% nEMG (95% CI 0-10; Cohen's d 0.30). However, years of training experience was positively associated with the ability to selectively activate the triceps (β = 0.41, P = 0.04), but not the pectoralis. Bench press 1RM was not significantly associated with the ability to selectively activate the muscles. Pectoralis activity can be increased when focusing on using this muscle during push-ups, whereas the ability to do this for the triceps is dependent on years of training experience. Maximal muscle strength does not appear to be a decisive factor for the ability to selectively activate these muscles.

  19. An on-line push/pull perfusion-based hollow-fiber liquid-phase microextraction system for high-performance liquid chromatographic determination of alkylphenols in water samples.

    Science.gov (United States)

    Chao, Yu-Ying; Jian, Zhi-Xuan; Tu, Yi-Ming; Wang, Hsaio-Wen; Huang, Yeou-Lih

    2013-06-07

    In this study, we employed a novel on-line method, push/pull perfusion hollow-fiber liquid-phase microextraction (PPP-HF-LPME), to extract 4-tert-butylphenol, 2,4-di-tert-butylphenol, 4-n-nonylphenol, and 4-n-octylphenol from river and tap water samples; we then separated and quantified the extracted analytes through high-performance liquid chromatography (HPLC). Using this approach, we overcame the problem of fluid loss across the porous HF membrane to the donor phase, permitting on-line coupling of HF-LPME to HPLC. In our PPP-HF-LPME system, we used a push/pull syringe pump as the driving source to perfuse the acceptor phase, while employing a heating mantle and an ultrasonic probe to accelerate mass transfer. We optimized the experimental conditions such as the nature of the HF supported intermediary phase and the acceptor phase, the composition of the donor and acceptor phases, the sample temperature, and the sonication conditions. Our proposed method provided relative standard deviations of 3.1-6.2%, coefficients of determination (r(2)) of 0.9989-0.9998, and limits of detection of 0.03-0.2 ng mL(-1) for the analytes under the optimized conditions. When we applied this method to analyses of river and tap water samples, our results confirmed that this microextraction technique allows reliable monitoring of alkylphenols in water samples.

  20. Photoinduced Charge Shifts and Electron Transfer in Viologen-Tetraphenylborate Complexes: Push-Pull Character of the Exciplex.

    Science.gov (United States)

    Santos, Willy G; Budkina, Darya S; Deflon, Victor M; Tarnovsky, Alexander N; Cardoso, Daniel R; Forbes, Malcolm D E

    2017-06-14

    Viologen-tetraarylborate ion-pair complexes were prepared and investigated by steady-state and time-resolved spectroscopic techniques such as fluorescence and femtosecond transient absorption. The results highlight a charge transfer transition that leads to changes in the viologen structure in the excited singlet state. Femtosecond transient absorption reveals the formation of excited-state absorption and stimulated emission bands assigned to the planar (k obs < 10 12 s -1 ) and twisted (k obs ∼ 10 10 s -1 ) structures between two pyridinium groups in the viologen ion. An efficient photoinduced electron transfer from the tetraphenylborate anionic moiety to the viologen dication was observed less than 1 μs after excitation. This is a consequence of the push-pull character of the electron donor twisted viologen structure, which helps formation of the borate triplet state. The borate triplet state is deactivated further via a second electron transfer process, generating viologen cation radical (V •+ ).

  1. Scapula kinematics of pull-up techniques: Avoiding impingement risk with training changes.

    Science.gov (United States)

    Prinold, Joe A I; Bull, Anthony M J

    2016-08-01

    Overhead athletic activities and scapula dyskinesia are linked with shoulder pathology; pull-ups are a common training method for some overhead sports. Different pull-up techniques exist: anecdotally some are easier to perform, and others linked to greater incidences of pathology. This study aims to quantify scapular kinematics and external forces for three pull-up techniques, thus discussing potential injury implications. An observational study was performed with eleven participants (age=26.8±2.4 years) who regularly perform pull-ups. The upward motions of three pull-up techniques were analysed: palms facing anterior, palms facing posterior and wide-grip. A skin-fixed scapula tracking technique with attached retro-reflective markers was used. High intra-participant repeatability was observed: mean coefficients of multiple correlations of 0.87-1.00 in humerothoracic rotations and 0.77-0.90 for scapulothoracic rotations. Standard deviations of hand force was low: kinematics were observed between the pull-up techniques. The reverse technique has extreme glenohumeral internal-external rotation and large deviation from the scapula plane. The wide technique has a reduced range of pro/retraction in the same HT plane of elevation and 90° of arm abduction with 45° external rotation was observed. All these factors suggest increased sub-acromial impingement risk. The scapula tracking technique showed high repeatability. High arm elevation during pull-ups reduces sub-acromial space and increases pressure, increasing the risk of impingement injury. Wide and reverse pull-ups demonstrate kinematics patterns linked with increased impingement risk. Weight-assisted front pull-ups require further investigation and could be recommended for weaker participants. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Uranium metalla-allenes with carbene imido R{sub 2}C=U{sup IV}=NR' units (R=Ph{sub 2}PNSiMe{sub 3}; R'=CPh{sub 3}): alkali-metal-mediated push-pull effects with an amido auxiliary

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Erli; Tuna, Floriana; Kaltsoyannis, Nikolas; Liddle, Stephen T. [School of Chemistry, The University of Manchester (United Kingdom); Lewis, William [School of Chemistry, The University of Nottingham (United Kingdom)

    2016-08-08

    We report uranium(IV)-carbene-imido-amide metalla-allene complexes [U(BIPM{sup TMS})(NCPh{sub 3})(NHCPh{sub 3})(M)] (BIPM{sup TMS}=C(PPh{sub 2}NSiMe{sub 3}){sub 2}; M=Li or K) that can be described as R{sub 2}C=U=NR' push-pull metalla-allene units, as organometallic counterparts of the well-known push-pull organic allenes. The solid-state structures reveal that the R{sub 2}C=U=NR' units adopt highly unusual cis-arrangements, which are also reproduced by gas-phase theoretical studies conducted without the alkali metals to remove their potential structure-directing roles. Computational studies confirm the double-bond nature of the U=NR' and U=CR{sub 2} interactions, the latter increasingly attenuated by potassium then lithium when compared to the hypothetical alkali-metal-free anion. Combined experimental and theoretical data show that the push-pull effect induced by the alkali metal cations and amide auxiliary gives a fundamental and tunable structural influence over the C=U{sup IV}=N units. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Pushing Back against Push-In: ESOL Teacher Resistance and the Complexities of Coteaching

    Science.gov (United States)

    McClure, Greg; Cahnmann-Taylor, Melisa

    2010-01-01

    As U. S. school districts struggle to address persistent achievement gaps between increasing numbers of English language learners (ELLs) and their native-English-speaking counterparts, many districts are moving away from segregative models like pull-out to implement more collaborative approaches such as coteaching, or push-in. In contrast to…

  4. Structural Change Out of Agriculture: Labor Push versus Labor Pull

    OpenAIRE

    Francisco Alvarez-Cuadrado; Markus Poschke

    2011-01-01

    The process of economic development is characterized by substantial rural-urban migrations and a decreasing share of agriculture in output and employment. The literature highlights two main engines behind this process of structural change: (i) improvements in agricultural technology combined with the effect of Engel's law of demand push resources out of the agricultural sector (the "labor push" hypothesis), and (ii) improvements in industrial technology attract labor into this sector (the "la...

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

    Science.gov (United States)

    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 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.

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

    Directory of Open Access Journals (Sweden)

    Joaquin Calatayud, Sebastien Borreani, Juan C. Colado, Fernando F Martín, Michael E. Rogers

    2014-09-01

    Full Text Available 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.

  7. Push and pull models to manage patient consent and licensing of multimedia resources in digital repositories for case-based reasoning.

    Science.gov (United States)

    Kononowicz, Andrzej A; Zary, Nabil; Davies, David; Heid, Jörn; Woodham, Luke; Hege, Inga

    2011-01-01

    Patient consents for distribution of multimedia constitute a significant element of medical case-based repositories in medicine. A technical challenge is posed by the right of patients to withdraw permission to disseminate their images or videos. A technical mechanism for spreading information about changes in multimedia usage licenses is sought. The authors gained their experience by developing and managing a large (>340 cases) repository of virtual patients within the European project eViP. The solution for dissemination of license status should reuse and extend existing metadata standards in medical education. Two methods: PUSH and PULL are described differing in the moment of update and the division of responsibilities between parties in the learning object exchange process. The authors recommend usage of the PUSH scenario because it is better adapted to legal requirements in many countries. It needs to be stressed that the solution is based on mutual trust of the exchange partners and therefore is most appropriate for use in educational alliances and consortia. It is hoped that the proposed models for exchanging consents and licensing information will become a crucial part of the technical frameworks for building case-based repositories.

  8. The United States and international climate cooperation: International 'pull' versus domestic 'push'

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Guri [Center for International Climate and Environmental Research, Oslo (Norway); Froyn, Camilla Bretteville [Center for International Climate and Environmental Research, Oslo (Norway); Hovi, Jon [Center for International Climate and Environmental Research, Oslo (Norway) and Department of Political Science, University of Oslo, P.O. Box 1097, 0317 Oslo (Norway)]. E-mail: jon.hovi@stv.uio.no; Menz, Fredric C. [Center for International Climate and Environmental Research, Oslo (Norway); School of Business, Clarkson University, Potsdam, NY 13699 (United States)

    2007-02-15

    The US government is being pressured by both international and domestic influences to re-engage in international climate control. This paper considers whether the international 'pull' and the domestic 'push' will be strong enough to accomplish this. First, we discuss whether changes in the architecture of the current climate regime might induce the United States to re-engage at the international level. We argue that the United States is unlikely to rejoin any global climate regime that is based on the Kyoto architecture, even if Kyoto were to be 'reformed'. Second, we discuss whether domestic political developments might eventually cause the United States to re-engage. We conclude that US re-engagement is likely to require the emergence of a new climate regime that basically extends US regulation to other countries. However, the forging of a unified US climate policy is still in the making. Furthermore, a new regime can gain widespread participation only if the Kyoto countries accept the idea of replacing Kyoto with some alternative architecture, which seems unlikely in the near future.

  9. Beyond technology-push and demand-pull: Lessons from California's solar policy

    International Nuclear Information System (INIS)

    Taylor, Margaret

    2008-01-01

    The scale of the technological transformation required to reduce greenhouse gas emissions to 'safe' levels while minimizing economic impacts necessitates an emphasis on designing climate policy to foster, or at least not impede, environmental innovation. There is only a weak empirical base for policy-makers to stand on regarding the comparative innovation effects of various climate policy options, however. Empirical scholarship in environmental innovation is hindered by the complexity of both the innovation process and the interactions between the dual market failures of pollution and innovation that are in play, and it appears that the field would benefit from the structure provided by a common lexicon. This paper focuses on the issues related to policy categorization in this field; these issues have received little attention in the literature despite their importance to making insights gained from empirical studies generalizable. The paper reviews the origins, strengths, and weaknesses of the dominant policy typology of technology-push versus demand-pull instruments. Its primary contribution, however, is to assemble a comprehensive chronology of solar policy in California and its impacts on innovation, where known, and then use this as a basis for building a new policy categorization that takes advantage of the intuitive resonance of the dominant typology, while encompassing the broader range of policy instruments that are employed in practice in order to stimulate environmental innovation. The most noteworthy aspect of the new categorization is that it introduces a third category of environmental innovation policy instrument that focuses on improving the interface between technology suppliers and users. This reflects developments in the economics of innovation literature as well as considerable evidence in the domain of distributed solar energy technologies that opportunism by some of the actors that work at this interface can be a barrier to innovation

  10. Low-Back Biomechanics and Static Stability During Isometric Pushing

    Science.gov (United States)

    Granata, Kevin P.; Bennett, Bradford C.

    2006-01-01

    Pushing and pulling tasks are increasingly prevalent in industrial workplaces. Few studies have investigated low-back biomechanical risk factors associated with pushing, and we are aware of none that has quantified spinal stability during pushing exertions. Data recorded from 11 healthy participants performing isometric pushing exertions demonstrated that trunk posture, vector force direction of the applied load, and trunk moment were influenced (p pushing task, and foot position. A biomechanical model was used to analyze the posture and hand force data gathered from the pushing exertions. Model results indicate that pushing exertions provide significantly (p pushing exertions. If one maintains stability by means of cocontraction, additional spinal load is thereby created, increasing the risk of overload injury. Thus it is important to consider muscle cocontraction when evaluating the biomechanics of pushing exertions. Potential applications of this research include improved assessment of biomechanical risk factors for the design of industrial pushing tasks. PMID:16435695

  11. Analysis of the behavior of orthogonal-core-type push-pull parametric transformer with iron and copper losses. Tetsuson oyobi doson wo koryoshita chokko jishinkei push pull parametric hen prime atsuki no dosa kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, K; Anazawa, Y; Kaga, A [Akita University, Akita (Japan). Mining College; Ichinokura, O [Tohoku University, Sendai (Japan). Faculty of Engineering

    1991-04-30

    This paper reports on a precise numerical analysis of operating characteristics of the push-pull parametric transformer of orthogonal-core type (proposed by the authors in the preceding papers) made in consideration of both the iron loss of its magnetic core and the copper loss of its windings. A model of magnetic circuit in the core is presented, which involves magnetic reluctances representing saturation characteristics of the core and magnetic inductances representing effects produced by hysteresis. Use is made of the function that expresses the saturation characteristics by a twenty-first power series of magnetic flux, the coefficient of each term being determined by use of experimental data on a specified sample of the magnetic core. Furthermore, recourse is had to the circuit simulator SPICE in order to analyze the operating characteristics of the transformer. Comparing results of the present analysis with experimental results, the following are noted: first, both output voltages and currents of windings of the transformer under the condition of parametric oscillation are calculated with sufficient accuracy; second, the present analysis is capable of evaluating the conversion efficiency of electric power and input power factor of the transformer, and of providing more accurate values of both voltage and current in the case of the maximum output under loading conditions as compared with the analyses so far presented. 8 refs., 11 figs., 2 tabs.

  12. A triphenylamine-based push-pull – σ – C60 dyad as photoactive molecular material for single-component organic solar cells: synthesis, characterizations and photophysical properties

    KAUST Repository

    Labrunie, Antoine; Gorenflot, Julien; Babics, Maxime; Aleveque, Olivier; Dabos-Seignon, Sylvie; Balawi, Ahmed H.; Kan, Zhipeng; Wohlfahrt, Markus; Levillain, Eric; Hudhomme, Pietrick; Beaujuge, Pierre; Laquai, Fré dé ric; Cabanetos, Clé ment; Blanchard, Philippe

    2018-01-01

    A push-pull – σ – C60 molecular dyad was synthesized via Huisgen-type click-chemistry and used as photoactive material for single-component organic solar cells. Steady-state photoluminescence (PL) experiments of the dyad in solution show a significant quenching of the emission of the push-pull moiety. Spin-casting of a solution of the dyad results in homogenous and smooth thin-films, which exhibit complete PL quenching in line with ultrafast photo-induced electron-transfer in the solid-state. Spectro-electrochemistry reveals the optical signatures of radical cations and radical anions. Evaluation of the charge carrier mobility by space-charge limited current measurements gives an electron-mobility of μe = 4.3 × 10-4 cm2 V-1 s-1, ca. 50 times higher than the hole-mobility. Single-component organic solar cells yield an open-circuit voltage Voc of 0.73 V and a short-circuit current density of 2.1 mA cm-2 however, a poor fill-factor FF (29%) is obtained, resulting in low power conversion efficiency of only 0.4%. Combined TA and time-delayed collection field (TDCF) experiments show mostly ultrafast photon-to-charge conversion and a small component of diffusion-limited exciton dissociation, revealing the presence of pure fullerene domains. Furthermore, a strong field dependence of charge generation is observed, governing the device fill factor, which is further reduced by a competition between extraction and fast recombination of separated charges.

  13. A triphenylamine-based push-pull – σ – C60 dyad as photoactive molecular material for single-component organic solar cells: synthesis, characterizations and photophysical properties

    KAUST Repository

    Labrunie, Antoine

    2018-04-23

    A push-pull – σ – C60 molecular dyad was synthesized via Huisgen-type click-chemistry and used as photoactive material for single-component organic solar cells. Steady-state photoluminescence (PL) experiments of the dyad in solution show a significant quenching of the emission of the push-pull moiety. Spin-casting of a solution of the dyad results in homogenous and smooth thin-films, which exhibit complete PL quenching in line with ultrafast photo-induced electron-transfer in the solid-state. Spectro-electrochemistry reveals the optical signatures of radical cations and radical anions. Evaluation of the charge carrier mobility by space-charge limited current measurements gives an electron-mobility of μe = 4.3 × 10-4 cm2 V-1 s-1, ca. 50 times higher than the hole-mobility. Single-component organic solar cells yield an open-circuit voltage Voc of 0.73 V and a short-circuit current density of 2.1 mA cm-2 however, a poor fill-factor FF (29%) is obtained, resulting in low power conversion efficiency of only 0.4%. Combined TA and time-delayed collection field (TDCF) experiments show mostly ultrafast photon-to-charge conversion and a small component of diffusion-limited exciton dissociation, revealing the presence of pure fullerene domains. Furthermore, a strong field dependence of charge generation is observed, governing the device fill factor, which is further reduced by a competition between extraction and fast recombination of separated charges.

  14. Friction Pull Plug Welding in Aluminum Alloys

    Science.gov (United States)

    Brooke, Shane A.; Bradford, Vann

    2012-01-01

    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  15. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    KAUST Repository

    Huang, Yi-Jen

    2016-04-07

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<±1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  16. Ergonomic study regarding sport trainingPush-ups simulation and analysis

    Directory of Open Access Journals (Sweden)

    Ion S. BOROZAN

    2012-06-01

    Full Text Available Some of the most common and helpful physical exercises used in sport training are the push-ups. Their biomechanics is analyzed in the paper and the author also gives an ergonomical study of this particular exercise with a complete simulation of the process.

  17. Push and pull factors determing wine tourism development in the 'Tri Morave' sub-region

    Directory of Open Access Journals (Sweden)

    Jovanović-Tončev Melita

    2016-01-01

    Full Text Available The subject of this paper are the factors affecting the decision of wine tourists to take a trip to a particular destination. These factors can be divided into internal (push and external (pull factors. The purpose of this study is to determine the development potential as well as the factors that influence participation in wine tourism in Tri Morave sub-region. In order to do that, two researches were conducted: one on the offer side and another on the demand side. Based on the results of the survey on the offer side, one can conclude that Tri Morave sub-region abounds in natural and anthropological resources that should be turned into an integrated wine product. On the other hand, research concerning tourist demand was conducted by polling winery visitors. The obtained data confirms assumptions about the appearance of modern tourists seeking authentic experience, satisfaction of hedonistic needs, and enjoyment of high-quality wine and food. Based on the results of the survey, the purchase of wine and wine tasting are the highest ranked benefits that tourists expect from visits to wineries. The application of Spearman's correlation coefficient points to statistically significant correlation between respondents, who referred to tasting, wine purchase, and authentic tourist experience as the basic motives of their visit, and future behavior of tourists in terms of revisiting and recommendations of the given wine destination to friends.

  18. Attentional Push: Augmenting Salience with Shared Attention Modeling

    OpenAIRE

    Gorji, Siavash; Clark, James J.

    2016-01-01

    We present a novel visual attention tracking technique based on Shared Attention modeling. Our proposed method models the viewer as a participant in the activity occurring in the scene. We go beyond image salience and instead of only computing the power of an image region to pull attention to it, we also consider the strength with which other regions of the image push attention to the region in question. We use the term Attentional Push to refer to the power of image regions to direct and man...

  19. Bright and photostable push-pull pyrene dye visualizes lipid order variation between plasma and intracellular membranes.

    Science.gov (United States)

    Niko, Yosuke; Didier, Pascal; Mely, Yves; Konishi, Gen-ichi; Klymchenko, Andrey S

    2016-01-11

    Imaging lipid organization in cell membranes requires advanced fluorescent probes. Here, we show that a recently synthesized push-pull pyrene (PA), similarly to popular probe Laurdan, changes the emission maximum as a function of lipid order, but outperforms it by spectroscopic properties. In addition to red-shifted absorption compatible with common 405 nm diode laser, PA shows higher brightness and much higher photostability than Laurdan in apolar membrane environments. Moreover, PA is compatible with two-photon excitation at wavelengths >800 nm, which was successfully used for ratiometric imaging of coexisting liquid ordered and disordered phases in giant unilamellar vesicles. Fluorescence confocal microscopy in Hela cells revealed that PA efficiently stains the plasma membrane and the intracellular membranes at >20-fold lower concentrations, as compared to Laurdan. Finally, ratiometric imaging using PA reveals variation of lipid order within different cellular compartments: plasma membranes are close to liquid ordered phase of model membranes composed of sphingomyelin and cholesterol, while intracellular membranes are much less ordered, matching well membranes composed of unsaturated phospholipids without cholesterol. These differences in the lipid order were confirmed by fluorescence lifetime imaging (FLIM) at the blue edge of PA emission band. PA probe constitutes thus a new powerful tool for biomembrane research.

  20. Pull-push mechanism for the 1,2-hydrogen rearrangement of carbenes. Substituent and deuterium isotope effects for thermal decomposition of 1-phenyl-2-diazopropanes

    International Nuclear Information System (INIS)

    Su, D.T.T.; Thornton, E.R.

    1978-01-01

    Intramolecular and intermolecular deuterium isotope effects have been measured for the thermal carbene H rearrangements of three substituted 1-phenyl-2-diazopropanes-1-d in hexane at 25 0 C. The isotope effects, k/sub H//k/sub D/, vary from ca. 1.2 to 1.5, increasing with electron-withdrawing substituents, for the formation of both cis- and trans-β-methylstyrenes. Product ratios were determined for these compounds as well as the corresponding undeuterated ones, permitting calculation of intermolecular primary and secondary isotope effects. In addition, the competition among the cis and trans products and the product of H migration from the terminal methyl group permitted determination of Hammett rho values of ca. -1 for the competition between benzylic and terminal migration. The results strongly indicate a ''pull-push'' mechanism, which can be pictured roughly as electrophilic attack on the C--H bond by the phantom p orbital of the carbene along with backside nucleophilic attack by the carbene unshared electron pair to push the H away and form the π bond. The data are believed to be consistent only with a nonzero barrier for the carbene hydrogen rearrangement

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

    Science.gov (United States)

    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.

  2. The Determination of Production and Distribution Policy in Push-Pull Production Chain with Supply Hub as the Junction Point

    Science.gov (United States)

    Sinaga, A. T.; Wangsaputra, R.

    2018-03-01

    The development of technology causes the needs of products and services become increasingly complex, diverse, and fluctuating. This causes the level of inter-company dependencies within a production chains increased. To be able to compete, efficiency improvements need to be done collaboratively in the production chain network. One of the efforts to increase efficiency is to harmonize production and distribution activities in the production chain network. This paper describes the harmonization of production and distribution activities by applying the use of push-pull system and supply hub in the production chain between two companies. The research methodology begins with conducting empirical and literature studies, formulating research questions, developing mathematical models, conducting trials and analyses, and taking conclusions. The relationship between the two companies is described in the MINLP mathematical model with the total cost of production chain as the objective function. Decisions generated by the mathematical models are the size of production lot, size of delivery lot, number of kanban, frequency of delivery, and the number of understock and overstock lot.

  3. Azo polymers with electronical push and pull structures prepared via RAFT polymerization and its photoinduced birefringence behavior

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available Two methacrylate monomers containing azo and electronical push and pull structure, e.g. 2-Methyl-acrylic-acid-2-{[4-(4-cyano-phenylazo-3-methyl-phenyl]-ethyl-amino-ethyl ester (MACP with cyano substituted and 2-Methylacrylic-acid-2-{ethyl-[4-(4-methoxy-phenylazo-3-methyl-phenyl]-amino}-ethyl ester (MAMP with methoxy substituted, were synthesized and polymerized using 2-cyanoprop-2-yl dithiobenzoate (CPDB as chain transfer agent and 2,2'-azobisisobutyronitrile (AIBN as initiator. The results showed that the polymerization displayed characteristics of ‘living’/controlled free radical polymerization. Thus, the obtained polymers, polyMACP (pMACP and polyMAMP (pMAMP, had controlled molecular weights and narrow molecular weights distribution. The chain extension experiments of pMACP and pMAMP using styrene as the second monomer were successfully carried out. The photo-induced trans-cis-trans isomerization kinetic of pMACP and pMAMP in chloroform solution were described. Marked differences in rate for the trans-cis and cis-trans isomerization of pMACP and pMAMP were observed in chloroform solution due to the different electronic effects in these two polymers. Photoinduced birefringence and surface relief grating (SRG of the pMACP and pMAMP were investigated in thin film state.

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

    Science.gov (United States)

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

    2012-01-01

    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 (...

  5. Physical Limits on the Precision of Mitotic Spindle Positioning by Microtubule Pushing forces: Mechanics of mitotic spindle positioning.

    Science.gov (United States)

    Howard, Jonathon; Garzon-Coral, Carlos

    2017-11-01

    Tissues are shaped and patterned by mechanical and chemical processes. A key mechanical process is the positioning of the mitotic spindle, which determines the size and location of the daughter cells within the tissue. Recent force and position-fluctuation measurements indicate that pushing forces, mediated by the polymerization of astral microtubules against- the cell cortex, maintain the mitotic spindle at the cell center in Caenorhabditis elegans embryos. The magnitude of the centering forces suggests that the physical limit on the accuracy and precision of this centering mechanism is determined by the number of pushing microtubules rather than by thermally driven fluctuations. In cells that divide asymmetrically, anti-centering, pulling forces generated by cortically located dyneins, in conjunction with microtubule depolymerization, oppose the pushing forces to drive spindle displacements away from the center. Thus, a balance of centering pushing forces and anti-centering pulling forces localize the mitotic spindles within dividing C. elegans cells. © 2017 The Authors. BioEssays published by Wiley Periodicals, Inc.

  6. Intrapartum translabial ultrasound with pushing used to predict the difficulty in vacuum-assisted delivery of fetuses in non-occiput posterior position.

    Science.gov (United States)

    Antonio Sainz, José; Borrero, Carlota; Aquise, Adriana; García-Mejido, José Antonio; Gutierrez, Laura; Fernández-Palacín, Ana

    2016-10-01

    Our aim is to evaluate the capacity of intrapartum translabial ultrasound (ITU) with pushing in the prediction of difficulty of fetal extraction in vacuum assisted deliveries. Prospective, observational study performed (2/2015-8/2015) on 75 nulliparous women, ≥37 weeks with singleton pregnancies at full dilatation who had ITU-with-pushing performed, previous to vacuum-placement for fetal extraction. Working on the translabial sagittal-plane, we assessed: Angle-Progression (AoP), Progression-Distance (PD) and Head-Direction (HD); in the axial plane we evaluated: Midline-Angle (MLA) and Head-Perineum-Distance (HPD). Vacuum extractions were classified as easy-difficulty (ED) (≤3 vacuum-pulls), difficult-unsuccessful (DD) (>3 vacuum-pulls). We did not assess occipito-posterior-presentations. Seventy nulliparous were studied (44-ED,26-DD). We observed no differences in obstetric, neonatal or intrapartum characteristics between the two study groups, with the following exceptions: newborn weight (3272 ± 438 g versus 3540 ± 372 g; p = 0.011) and number of vacuum-pulls (1.4-ED-vs-4.4-DD; p pushing was 143.9° ± 14.6° in ED and 115.1°± 12.9° in DD (p Pushing was 42.7 ± 11.3 mm versus 30.4 ± 9.8 mm (p Pushing was 27.6°± 26.6° versus 57.5°±26.5°(p=0.025); HPD-Pushing was 40.8 ± 10.0 mm versus 47.4 ± 10.9 mm (p = 0.039). We identified that the presence of an AoP-Pushing > 128° predicts an Easy-Vacuum-Delivery (≤3 Vacuum-Pulls) in  >85% of cases (Sen 80%-FPR 9.3%).

  7. Morphisms of Extensions of C*-algebras: Pushing Forward the Busby Invariant

    DEFF Research Database (Denmark)

    Eilers, Søren; Loring, Terry A.; Pedersen, Gert Kjærgård

    1999-01-01

    of varying severity, on the given vertical maps and describe the solutions in terms of push-outs and pull-backs of certain diagrams. Our characterization of the universal solution to one of the diagrams yields a concrete description of various amalgamated free products. This leads to new results about the K...

  8. Choices of Destination for Transnational Higher Education: "Pull" Factors in an Asia Pacific Market

    Science.gov (United States)

    Ahmad, Syed Zamberi; Buchanan, Frederick Robert

    2016-01-01

    Traditional assumptions favouring native English language countries in transnational higher education (TNHE) overlook experiences of international students in new emerging Asian education hubs. Specifically, there has been limited research relating to international students' choice for studying in Malaysia. Drawing from the "push-pull"…

  9. Effect of different pushing speeds on bench press.

    Science.gov (United States)

    Padulo, J; Mignogna, P; Mignardi, S; Tonni, F; D'Ottavio, S

    2012-05-01

    The purpose of this study was to investigate the effect on muscular strength after a 3-week training with the bench-press at a fixed pushing of 80-100% maximal speed (FPS) and self-selected pushing speed (SPS). 20 resistance-trained subjects were divided at random in 2 groups differing only regarding the pushing speed: in the FPS group (n=10) it was equal to 80-100% of the maximal speed while in the SPS group (n=10) the pushing speed was self-selected. Both groups were trained twice a week for 3 weeks with a load equal to 85% of 1RM and monitored with the encoder. Before and after the training we measured pushing speed and maximum load. Significant differences between and within the 2 groups were pointed out using a 2-way ANOVA for repeated measures. After 3 weeks a significant improvement was shown especially in the FPS group: the maximum load improved by 10.20% and the maximal speed by 2.22%, while in the SPS group the effect was <1%. This study shows that a high velocity training is required to increase the muscle strength further in subjects with a long training experience and this is possible by measuring the individual performance speed for each load. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Demonstration of In situ Anaerobic Transformation of Toluene and Xylene Using Single-Well Push-Pull Tests and Deuterated BTEX Surrogates

    Science.gov (United States)

    Field, J. A.; Reusser, D. E.; Beller, H. R.; Istok, J. D.

    2001-12-01

    Obtaining unambiguous evidence of in-situ transformation of benzene, toluene, ethylbenzene and xylene (BTEX) in the subsurface is a difficult task. Recently, benzylsuccinic acid and its methyl analogues were shown to be unequivocal degradation products of anaerobic toluene and xylene biodegradation. Conducting tracer tests at BTEX-contaminated field sites is problematic because background contaminant concentrations potentially interfere with the interpretation of field test data. To avoid the time and cost associated with removing background contaminants, alternative approaches are needed. Deuterated analogs of toluene and xylene are well-suited for use in field tracer tests because they are inexpensive and can be distinguished analytically from background toluene and xylene. In this study, single-well push-pull tests, in which deuterated toluene and xylene were injected, were performed to assess the in-situ anaerobic biotransformation of toluene and xylene in BTEX-contaminated wells. A total of 4 single-well push-pull tests were conducted at BTEX-contaminated field sites near Portland, OR and Kansas City, KS. Test solutions consisting of 100 mg/L bromide, 250 mg/L nitrate, 0.4 to 2.5 mg/L toluene-d8, and 0.4 to 1.0 mg/L o-xylene-d10.were injected at a rate of 0.5 - 2 L/min. During the extraction phase, samples were taken daily to biweekly for up to 30 days. Samples for volatile organic analytes were collected in 40-mL volatile organic analysis (VOA) vials without headspace. Samples for BSA and methyl-BSA were collected in 1 L glass bottles and preserved with 5% (w/w) formalin. Samples were shipped on ice and stored at 4 C until analysis. Unambiguous evidence of toluene and xylene biotransformation was obtained with the in-situ formation of BSA and methyl-BSA. The concentrations of BSA ranged from below the detection limit (0.2 ug/L) to 1.5 ug/L. The concentrations of methyl-BSA ranged from below detection to the quantitation limit (0.7 ug/L). The highest BSA

  11. Pushing, pulling and electromagnetic radiation force cloaking by a pair of conducting cylindrical particles

    Science.gov (United States)

    Mitri, F. G.

    2018-02-01

    The present analysis shows that two conducting cylindrical particles illuminated by an axially-polarized electric field of plane progressive waves at arbitrary incidence will attract, repel or become totally cloaked (i.e., invisible to the transfer of linear momentum carried by the incident waves), depending on their sizes, the interparticle distance as well as the angle of incidence of the incident field. Based on the rigorous multipole expansion method and the translational addition theorem of cylindrical wave functions, the electromagnetic (EM) radiation forces arising from multiple scattering effects between a pair of perfectly conducting cylindrical particles of circular cross-sections are derived and computed. An effective incident field on a particular particle is determined first, and used subsequently with its corresponding scattered field to derive the closed-form analytical expressions for the radiation force vector components. The mathematical expressions for the EM radiation force components (i.e. longitudinal and transverse) are exact, and have been formulated in partial-wave series expansions in cylindrical coordinates involving the angle of incidence, the interparticle distance and the expansion coefficients. Numerical examples illustrate the analysis for two perfectly conducting circular cylinders in a homogeneous nonmagnetic medium of wave propagation. The computations for the dimensionless radiation force functions are performed with particular emphasis on varying the angle of incidence, the interparticle distance, and the sizes of the particles. Depending on the interparticle distance and angle of incidence, the cylinders yield total neutrality (or invisibility); they experience no force and become unresponsive to the transfer of the EM linear momentum due to multiple scattering cancellation effects. Moreover, pushing or pulling EM forces between the two cylinders arise depending on the interparticle distance, the angle of incidence and their

  12. Shoulder joint loading and posture during medicine cart pushing task.

    Science.gov (United States)

    Xu, Xu; Lin, Jia-Hua; Boyer, Jon

    2013-01-01

    Excessive physical loads and awkward shoulder postures during pushing and pulling are risk factors for shoulder pain. Pushing a medicine cart is a major component of a work shift for nurses and medical assistants in hospitals and other health care facilities. A laboratory experiment was conducted to examine the effects of common factors (e.g., lane congestion, cart load stability, floor surface friction) on shoulder joint moment and shoulder elevation angle of participants during cart pushing. Participants pushed a medicine cart on straight tracks and turning around right-angle corners. Peak shoulder joint moments reached 25.1 Nm, 20.3 Nm, and 26.8 Nm for initial, transition, and turning phases of the pushing tasks, indicating that shoulder joint loading while pushing a medical cart is comparable to levels previously reported from heavy manual activities encountered in industry (e.g., garbage collection). Also, except for user experience, all other main study factors, including congestion level, cart load stability, location of transition strip, shoulder tendency, surface friction, and handedness, significantly influenced shoulder joint moment and shoulder elevation angle. The findings provide a better understanding of shoulder exposures associated with medicine cart operations and may be helpful in designing and optimizing the physical environment where medicine carts are used.

  13. Attainment and retention of force moderation following laparoscopic resection training with visual force feedback.

    Science.gov (United States)

    Hernandez, Rafael; Onar-Thomas, Arzu; Travascio, Francesco; Asfour, Shihab

    2017-11-01

    Laparoscopic training with visual force feedback can lead to immediate improvements in force moderation. However, the long-term retention of this kind of learning and its potential decay are yet unclear. A laparoscopic resection task and force sensing apparatus were designed to assess the benefits of visual force feedback training. Twenty-two male university students with no previous experience in laparoscopy underwent relevant FLS proficiency training. Participants were randomly assigned to either a control or treatment group. Both groups trained on the task for 2 weeks as follows: initial baseline, sixteen training trials, and post-test immediately after. The treatment group had visual force feedback during training, whereas the control group did not. Participants then performed four weekly test trials to assess long-term retention of training. Outcomes recorded were maximum pulling and pushing forces, completion time, and rated task difficulty. Extreme maximum pulling force values were tapered throughout both the training and retention periods. Average maximum pushing forces were significantly lowered towards the end of training and during retention period. No significant decay of applied force learning was found during the 4-week retention period. Completion time and rated task difficulty were higher during training, but results indicate that the difference eventually fades during the retention period. Significant differences in aptitude across participants were found. Visual force feedback training improves on certain aspects of force moderation in a laparoscopic resection task. Results suggest that with enough training there is no significant decay of learning within the first month of the retention period. It is essential to account for differences in aptitude between individuals in this type of longitudinal research. This study shows how an inexpensive force measuring system can be used with an FLS Trainer System after some retrofitting. Surgical

  14. A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

    International Nuclear Information System (INIS)

    Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.; Rebecca, L.; Lalnunthari, J.; Thanga, H. H.

    2016-01-01

    Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

  15. Push-Pull Type Porphyrin Based Sensitizers: The Effect of Donor Structure on the Light-Harvesting Ability and Photovoltaic Performance

    KAUST Repository

    Qi, Qingbiao; Li, Renzhi; Luo, Jie; Zheng, Bin; Huang, Kuo-Wei; Wang, Peng; Wu, Jishan

    2015-01-01

    Push-pull type porphyrin-based sensitizers have become promising candidates for high-efficiency dye sensitized solar cells (DSCs). It is of importance to understand the fundamental structure-physical property-photovoltaic performance relationships by varying the donor and acceptor moieties. In this work, two new porphyrin-based sensitizers, WW-7 and WW-8, were synthesized and compared with the known sensitizer YD20. All the three dyes have the same porphyrin core and acceptor group (ethynylbenzoic acid) but their donor groups vary from the triphenylamine in YD20 to meso-diphenylaminoanthracene in WW-7 to N-phenyl carbazole in WW-8. Co(II/III)-based DSC device characterizations revealed that WW-7 showed enhanced light harvesting ability in comparison to YD20 with improved incident photon-to-collected electron conversion efficiencies (IPCEs). As a result, WW-7 displayed much higher short circuit current (Jsc: 13.54 mA cm-2) and open-circuit voltage (Voc: 0.829 V), with a power conversion efficiency (η) as high as 7.7%. Under the same conditions, YD20 cell exhibited a power conversion efficiency of 6.6% and the dye WW-8 showed even lower efficiency (η = 4.6%). Detailed physical measurements and theoretic calculations were conducted to understand the difference and reveal how three different donor structures affect their molecular orbital profile, light-harvesting ability, energy level alignment, and eventually the photovoltaic performance.

  16. Push-Pull Type Porphyrin Based Sensitizers: The Effect of Donor Structure on the Light-Harvesting Ability and Photovoltaic Performance

    KAUST Repository

    Qi, Qingbiao

    2015-06-23

    Push-pull type porphyrin-based sensitizers have become promising candidates for high-efficiency dye sensitized solar cells (DSCs). It is of importance to understand the fundamental structure-physical property-photovoltaic performance relationships by varying the donor and acceptor moieties. In this work, two new porphyrin-based sensitizers, WW-7 and WW-8, were synthesized and compared with the known sensitizer YD20. All the three dyes have the same porphyrin core and acceptor group (ethynylbenzoic acid) but their donor groups vary from the triphenylamine in YD20 to meso-diphenylaminoanthracene in WW-7 to N-phenyl carbazole in WW-8. Co(II/III)-based DSC device characterizations revealed that WW-7 showed enhanced light harvesting ability in comparison to YD20 with improved incident photon-to-collected electron conversion efficiencies (IPCEs). As a result, WW-7 displayed much higher short circuit current (Jsc: 13.54 mA cm-2) and open-circuit voltage (Voc: 0.829 V), with a power conversion efficiency (η) as high as 7.7%. Under the same conditions, YD20 cell exhibited a power conversion efficiency of 6.6% and the dye WW-8 showed even lower efficiency (η = 4.6%). Detailed physical measurements and theoretic calculations were conducted to understand the difference and reveal how three different donor structures affect their molecular orbital profile, light-harvesting ability, energy level alignment, and eventually the photovoltaic performance.

  17. Ground reaction force characteristics of Tai Chi push hand.

    Science.gov (United States)

    Chang, Yao-Ting; Chang, Jia-Hao; Huang, Chen-Fu

    2014-01-01

    Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s(-1)) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant's body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.

  18. Design of an expert system for the development and formulation of push-pull osmotic pump tablets containing poorly water-soluble drugs.

    Science.gov (United States)

    Zhang, Zhi-hong; Dong, Hong-ye; Peng, Bo; Liu, Hong-fei; Li, Chun-lei; Liang, Min; Pan, Wei-san

    2011-05-30

    The purpose of this article was to build an expert system for the development and formulation of push-pull osmotic pump tablets (PPOP). Hundreds of PPOP formulations were studied according to different poorly water-soluble drugs and pharmaceutical acceptable excipients. The knowledge base including database and rule base was built based on the reported results of hundreds of PPOP formulations containing different poorly water-soluble drugs and pharmaceutical excipients and the experiences available from other researchers. The prediction model of release behavior was built using back propagation (BP) neural network, which is good at nonlinear mapping and learning function. Formulation design model was established based on the prediction model of release behavior, which was the nucleus of the inference engine. Finally, the expert system program was constructed by VB.NET associating with SQL Server. Expert system is one of the most popular aspects in artificial intelligence. To date there is no expert system available for the formulation of controlled release dosage forms yet. Moreover, osmotic pump technology (OPT) is gradually getting consummate all over the world. It is meaningful to apply expert system on OPT. Famotidine, a water insoluble drug was chosen as the model drug to validate the applicability of the developed expert system. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Using a train drawn by a locomotive engine or a taking a railway-motor train?; Lokbespannung oder Triebzuege?

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, V. [Siemens Verkehrstechnik Erlangen (Germany). ICE-Marketing

    2000-10-01

    In the field of passenger rail traffic extending from urban transport to long-distance railroad different requirements lead in the past to different developments with regard to forming a train. Using trains hauled by a locomotive. Using a push and pull train or a adistributed power train, and had to be decided with operational and economical considerations in mind. Nevertheless, besides factual and objective arguments there are also arguments to be attributed to the level of training and to emotions. Therefore, the author finally tries to arrive at an assessable conclusion by means of a comparison of the life cycle costs of two real trains running under comparable operational conditions. (orig.) [German] Zur Lokomotive eroeffnet die elektrische Traktion in Form eines Triebzuges oder Triebwagens eine Alternative mit verteilter Antriebstechnik. Fuer beide Varianten gibt es typische Anwendungsfaelle. Im Personenfernverkehr koennen beide Zugarten fallweise Vorteile fuer Betreiber und Fahrgaeste haben. Eine LCC-Betrachtung fuer beide Zugarten soll neben betrieblichen Argumenten eine Entscheidungshilfe geben. (orig.)

  20. Silicon Nitride Deposition for Flexible Organic Electronic Devices by VHF (162 MHz)-PECVD Using a Multi-Tile Push-Pull Plasma Source.

    Science.gov (United States)

    Kim, Ki Seok; Kim, Ki Hyun; Ji, You Jin; Park, Jin Woo; Shin, Jae Hee; Ellingboe, Albert Rogers; Yeom, Geun Young

    2017-10-19

    Depositing a barrier film for moisture protection without damage at a low temperature is one of the most important steps for organic-based electronic devices. In this study, the authors investigated depositing thin, high-quality SiN x film on organic-based electronic devices, specifically, very high-frequency (162 MHz) plasma-enhanced chemical vapor deposition (VHF-PECVD) using a multi-tile push-pull plasma source with a gas mixture of NH 3 /SiH 4 at a low temperature of 80 °C. The thin deposited SiN x film exhibited excellent properties in the stoichiometry, chemical bonding, stress, and step coverage. Thin film quality and plasma damage were investigated by the water vapor transmission rate (WVTR) and by electrical characteristics of organic light-emitting diode (OLED) devices deposited with SiN x , respectively. The thin deposited SiN x film exhibited a low WVTR of 4.39 × 10 -4  g (m 2 · day) -1 for a single thin (430 nm thick) film SiN x and the electrical characteristics of OLED devices before and after the thin SiN x film deposition on the devices did not change, which indicated no electrical damage during the deposition of SiN x on the OLED device.

  1. Optimal regenerative braking with a push-belt CVT: an experimental study

    NARCIS (Netherlands)

    Berkel, van K.; Hofman, T.; Vroemen, B.G.; Steinbuch, M.

    2010-01-01

    This paper describes the approach and the results of efficiency experiments on a push-belt Continuously Variable Transmission (CVT) in a new hybrid drive train. The hybrid drive train uses the push-belt CVT to charge a flywheel, with the kinetic energy of the vehicle during regenerative braking and

  2. Optimal regenerative braking with a push-belt CVT : an experimental study

    NARCIS (Netherlands)

    van Berkel, K.; Hofman, T.; Vroemen, B.; Steinbuch, M.

    2010-01-01

    This paper describes the approach and the results of efficiency experiments on a push-belt Continuously Variable Transmission (CVT) in a new hybrid drive train. The hybrid drive train uses the push-belt CVT to “charge” a flywheel, with the kinetic energy of the vehicle during regenerative braking

  3. Effect of intercalation and chromophore arrangement on the linear and nonlinear optical properties of model aminopyridine push–pull molecules

    Czech Academy of Sciences Publication Activity Database

    Bureš, F.; Cvejn, D.; Melánová, Klára; Beneš, L.; Svoboda, Jan; Zima, Vítězslav; Pytela, O.; Mikysek, T.; Růžičková, Z.; Kityk, I. V.; Wojciechowski, A.; AlZayed, N.

    2016-01-01

    Roč. 4, č. 3 (2016), s. 468-478 ISSN 2050-7526 R&D Projects: GA ČR(CZ) GA13-01061S Institutional support: RVO:61389013 Keywords : push-pull chromophore * intercalation * layered phosphates Subject RIV: CA - Inorganic Chemistry Impact factor: 5.256, year: 2016

  4. Energy requirements of tire pulling.

    Science.gov (United States)

    Fredriksen, Per M; Mamen, Asgeir

    2017-10-01

    We have investigated the effect using walking poles and pulling tires at 4 and 6 km·h-1 (1.11 and 1.67 m·s-1) speeds on oxygen uptake (V̇O2) and heart rate. Eleven subjects, 6 males, with a mean (SD) age of 25.2 (6.9) years participated in field tests involving walking without poles, walking with poles and tire pulling with poles. Increasing the load caused the largest increases in energy demand, more than 4 MET. Speed increase also caused substantial energy increase, approximately 4 MET. Increasing the inclination only modestly increased the oxygen uptake, approximately 2 MET. In both level walking and uphill walking, using poles marginally increased oxygen uptake compared to working without poles. Pulling one tire (12.5 kg) required an oxygen uptake of 27 (4) mL·kg-1·min-1 at 4 km·h-1 and 0% inclination. Adding one more tire (6 kg) drove the oxygen uptake further up to 39 (4) mL·kg-1·min-1. This is close to the requirement of level running at 10.5 km·h-1. Pulling both tires at 6 km·h-1 and 5% inclination required a V̇O2 of 54 (6) mL·kg-1·min-1, equal to running uphill at 5% inclination and 12.5 km·h-1 speed. Heart rate rose comparably with oxygen uptake. At 4 km·h-1 and 0% inclination the increase was 29 bpm, from 134 (21) to 163 (22) bpm when going from pulling one tire to two tires. In the hardest exercise, 6 km·h-1 and 5% inclination, heart rate reached 174 (14) bpm. The study showed that tire pulling even at slow speeds has an energy requirement that is so large that the activity may be feasible as endurance training.

  5. Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push-Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Fernandes, Sara S M; Castro, M Cidália R; Pereira, Ana Isabel; Mendes, Adélio; Serpa, Carlos; Pina, João; Justino, Licínia L G; Burrows, Hugh D; Raposo, M Manuela M

    2017-12-31

    The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push-pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO 2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine-thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO 2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20-64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%.

  6. Push-pull-thinking

    DEFF Research Database (Denmark)

    Kolodovski, A.

    2006-01-01

    Scientific innovation takes two distinct paths. Sometimes, companies ask researchers to develop a solution for a specific business problem. This is a demand-driven, “PULL” method. In other cases, scientists develop a technology with new valuablecapabilities, and then search for commercial applica...

  7. Comparison of the effects of an eight-week push-up program using stable versus unstable surfaces.

    Science.gov (United States)

    Chulvi-Medrano, Iván; Martínez-Ballester, Esteban; Masiá-Tortosa, Laura

    2012-12-01

    Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push-up training on stable and unstable surfaces had on strength performance in healthy young men. Thirty subjects with experience in resistance training participated in push-up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T-Bow® (TBp) or the BOSU® (Bp). Strength, as measured by one repetition maximum (1-RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups. The addition of unstable surfaces in push-up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men. 3b.

  8. 49 CFR 220.49 - Radio communication used in shoving, backing or pushing movements.

    Science.gov (United States)

    2010-10-01

    ... 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 movements. When radio communication is used in connection with the shoving, backing or pushing of a train...

  9. Electromyographical Comparison of a Traditional, Suspension Device, and Towel Pull-Up

    Directory of Open Access Journals (Sweden)

    Snarr Ronald L.

    2017-08-01

    Full Text Available Strengthening muscles of the back may have various implications for improving functions of daily living, aiding in the transfer of power in throwing, and assist in injury prevention of the shoulder complex. While several versions of the pull-up exist, there is currently no literature comparing their differences. The purpose of this investigation was to compare the electromyographical activity of the latissimus dorsi, posterior deltoid, middle trapezius, and biceps brachii while performing three variations of the pull-up. Resistance-trained men and women (n =15, age = 24.87 ± 6.52 years participated in this study by performing traditional pull-ups, suspension device pull-ups, and towel pull-ups in a randomized fashion. Each pull-up was performed for three repetitions with a 1.5 bi-acromial grip-width for each participant. Normalized (%MVC electromyographical values were recorded for each muscle group during each pull-up variation. No significant differences existed within the latissimus dorsi, biceps brachii or posterior deltoid between any of the exercises. For the middle trapezius, towel pull-ups provided significantly lower muscle activity than the traditional pull-up, while no differences between suspension pull-ups and the other variations occurred. In conclusion, only one muscular difference existed between the exercise variations and all versions examined provided electromyographical values, determined by current literature, to invoke a sufficient stimulus to promote increases in muscle strength and hypertrophy. Although further research is needed, practitioners can be confident when programming any of the movement variations examined when attempting to elicit adaptations of muscular strength and hypertrophy.

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

    Science.gov (United States)

    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. Trichotillomania (Hair-Pulling Disorder)

    Science.gov (United States)

    ... pulling Biting, chewing or eating pulled-out hair Playing with pulled-out hair or rubbing it across ... of trichotillomania: Family history. Genetics may play a role in the development of trichotillomania, and the disorder ...

  12. Effects of Angle Variations in Suspension Push-up Exercise.

    Science.gov (United States)

    Gulmez, Irfan

    2017-04-01

    Gulmez, I. Effects of angle variations in suspension push-up exercise. J Strength Cond Res 31(4): 1017-1023, 2017-This study aimed to determine and compare the amount of loads on the TRX Suspension Trainer (TRX) straps and ground reaction forces at 4 different angles during TRX push-ups. Twenty-eight male (mean age, 24.1 ± 2.9 years; height, 179.4 ± 8.0 m; weight, 78.8 ± 9.8 kg) physical education and sports university students participated in this study. The subjects were tested at TRX angles (0, 15, 30, 45°) during the TRX push-ups. Force data were recorded by a force platform and load cells integrated into the TRX straps. The results show that as the TRX angle was reduced, the load applied to the TRX straps increased and simultaneously the load measured by the force platform decreased. This was true for both the elbow joint changing from flexion to extension and vice versa. When the TRX angle was set at 0° and subjects' elbows were at extension during TRX push-up, 50.4% of the subjects' body weight, and when the elbows were at flexion, 75.3% of the body weight was registered by the sensors on the TRX straps. The results of this study can be used in the calculation of the training load and volume (resistance training programming) during TRX push-up exercises at varying angles.

  13. Analysis of pushing exercises: muscle activity and spine load while contrasting techniques on stable surfaces with a labile suspension strap training system.

    Science.gov (United States)

    McGill, Stuart M; Cannon, Jordan; Andersen, Jordan T

    2014-01-01

    Labile surfaces in the form of suspension straps are increasingly being used as a tool in resistance training programs. Pushing is a common functional activity of daily living and inherently part of a well-rounded training program. This study examined pushing exercises performed on stable surfaces and unstable suspension straps, specifically muscle activation levels and spine loads were quantified together with the influence of employing technique coaching. There were several main questions that this study sought to answer: Which exercises challenged particular muscles? What was the magnitude of the resulting spine load? How did stable and unstable surfaces differ? Did coaching influence the results? Fourteen men were recruited as part of a convenience sample (mean age, 21.1 ± 2.0 years; height, 1.77 ± 0.06 m; mean weight, 74.6 ± 7.8 kg). Data were processed and input to a sophisticated and anatomically detailed 3D model that used muscle activity and body segment kinematics to estimate muscle force-in this way, the model was sensitive to the individuals choice of motor control for each task; muscle forces and linked segment joint loads were used to calculate spine loads. Exercises were performed using stable surfaces for hand/feet contact and repeated where possible with labile suspension straps. Speed of movement was standardized across participants with the use of a metronome for each exercise. There were gradations of muscle activity and spine load characteristics to every task. In general, the instability associated with the labile exercises required greater torso muscle activity than when performed on stable surfaces. Throughout the duration of an exercise, there was a range of compression; the TRX push-up ranged from 1,653 to 2,128.14 N, whereas the standard push-up had a range from 1,233.75 to 1,530.06 N. There was no significant effect of exercise on spine compression (F(4,60) = 0.86, p = 0.495). Interestingly, a standard push-up showed significantly

  14. A Highly Automated, Wireless Inertial Measurement Unit Based System for Monitoring Gym-Based Push-Start Training Sessions by Bob-Skeleton Athletes

    Directory of Open Access Journals (Sweden)

    Mark GAFFNEY

    2015-01-01

    Full Text Available Wireless Inertial Measurement Units (WIMUs are increasingly used to improve our understanding of complex human motion scenarios. In sports this allows for more valid coaching, selection and training methods leading to improved athletic performance. The Push-Start in the Winter Olympic sport of Bob-Skeleton is poorly understood but believed to be critical to performance. At the University of Bath a piece of gym-based equipment called the “Assassin” used by athletes to practice the Push-Start was instrumented with a custom WIMU system to investigate this motion regime. A test subject performed 36 runs, comprising 3 runs at each of 12 combinations of 3 Incline and 4 Weight settings. A developed algorithm automatically identified valid data-files, extracted the Pushing-Phase Acceleration data, and estimated sled Velocity and Displacement. The average velocities derived from an existing Light-Gate and WIMU data-files were comparable, with an average Root Mean Squared Error of 0.105 meters per second over the 52 valid WIMU data-files identified, covering 11 of the 12 Weight and Incline settings. Additional investigation of WIMU data revealed information such as: step count; track incline; and whether weights had been added could be determined, although further verification and validation of these features are required. Such an automated WIMU-based system could replace performance monitoring methods such as Light-Gates, providing higher fidelity performance data, additional information on equipment setup with lower-cost and greater ease-of-use by coaches or athletes. Its portable and modular nature also allow use with other training scenarios or equipment, such as using additional on-body WIMUs, or use with outdoor and ice-track sleds, enabling performance monitoring from the gym to the ice-track for improved candidate selection, comparison and training in Bob-Skeleton and other ice-track based sled sports.

  15. Contribution of limb momentum to power transfer in athletic wheelchair pushing.

    Science.gov (United States)

    Masson, G; Bégin, M-A; Lopez Poncelas, M; Pelletier, S-K; Lessard, J-L; Laroche, J; Berrigan, F; Langelier, E; Smeesters, C; Rancourt, D

    2016-09-06

    Pushing capacity is a key parameter in athletic racing wheelchair performance. This study estimated the potential contribution of upper limb momentum to pushing. The question is relevant since it may affect the training strategy adopted by an athlete. A muscle-free Lagrangian dynamic model of the upper limb segments was developed and theoretical predictions of power transfer to the wheelchair were computed during the push phase. Results show that limb momentum capacity for pushing can be in the order of 40J per push cycle at 10m/s, but it varies with the specific pushing range chosen by the athlete. Although use of momentum could certainly help an athlete improve performance, quantifying the actual contribution of limb momentum to pushing is not trivial. A preliminary experimental investigation on an ergometer, along with a simplified model of the upper limb, suggests that momentum is not the sole contributor to power transfer to a wheelchair. Muscles substantially contribute to pushing, even at high speeds. Moreover, an optimal pushing range is challenging to find since it most likely differs if an athlete chooses a limb momentum pushing strategy versus a muscular exertion pushing strategy, or both at the same time. The study emphasizes the importance of controlling pushing range, although one should optimize it while also taking the dynamics of the recovery period into account. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Hair Pulling (Trichotillomania)

    Science.gov (United States)

    ... for Families - Vietnamese Spanish Facts for Families Guide Hair Pulling (Trichotillomania) No. 96; Reviewed July 2013 It ... for children and adolescents to play with their hair. However, frequent or obsessive hair pulling can lead ...

  17. Relationship between push phase and final race time in skeleton performance.

    Science.gov (United States)

    Zanoletti, Costanza; La Torre, Antonio; Merati, Giampiero; Rampinini, Ermanno; Impellizzeri, Franco M

    2006-08-01

    The aim of this study was to examine the relationship between push-time and final race time in skeleton participants during a series of major international competitions to determine the importance of the push phase in skeleton performance. Correlations were computed from the first and second heat split data measured during 24 men and 24 women skeleton competitions. Body mass, height, age, and years of experience of the first 30 men and women athletes of the skeleton, bobsleigh and luge 2003-2004 World Cup ranking were used for the comparison between sliding sports. Moderate but significant correlations (p push-time and final race time in men (r(mean) = 0.48) and women (r(mean) = 0.63). No correlations were found between changes in the individual push-time between the first and second heat with the corresponding changes in final race time. The bobsleigh sliders are heavier than the athletes of the other sliding disciplines. Luge athletes have more experience and are younger than bobsleigh and skeleton sliders. The results of this study suggest that a fast push phase is a prerequisite to success in competition and confirms that the selection of skeleton athletes based on the ability to accelerate to a maximum speed quickly could be valid. However, a good or improved push-time does not ensure a placement in the top finishing positions. On the basis of these results, we suggest that strength and power training is necessary to maintain a short push-time but additional physical training aimed to enhance the push phase might not reflect performance improvements. The recruitment of younger athletes and an increase of youthful competitive activity may be another effective way to reach international competitive results.

  18. Comparison of Olympic and Hexagonal Barbells With Midthigh Pull, Deadlift, and Countermovement Jump.

    Science.gov (United States)

    Malyszek, Kylie K; Harmon, RoQue A; Dunnick, Dustin D; Costa, Pablo B; Coburn, Jared W; Brown, Lee E

    2017-01-01

    Malyszek, KK, Harmon, RA, Dunnick, DD, Costa, PB, Coburn, JW, and Brown, LE. Comparison of olympic and hexagonal barbells with midthigh pull, deadlift, and countermovement jump. J Strength Cond Res 31(1): 140-145, 2017-Those training for strength and power commonly use different bars and different lifts. The hexagonal barbell (HBar) and Olympic barbell (OBar) are frequently used training implements, and the midthigh pull (MTP) and deadlift (DL) are 2 popular exercises. Therefore, the purpose of this study was to compare force between an HBar and OBar for a MTP, DL, and countermovement jump (CMJ). Twenty resistance-trained men (age = 24.05 ± 2.09 years, ht = 178.07 ± 7.05 cm, mass = 91.42 ± 14.44 kg) volunteered to participate and performed MTP and DL using both bars and a CMJ. Joint angles were recorded for all pulls and the bottom position of the CMJ. Peak ground reaction force (PGRF) was greater in the MTP (3,186.88 ± 543.53 N) than DL (2,501.15 ± 404.04 N) but not different between bars. Midthigh pull joint angles were more extended than DL, and the strongest correlations between isometric and dynamic performance were seen between DL PGRF and CMJ impulse (OBar r = 0.85; HBar r = 0.84). These findings are likely because of the different anatomical characteristics between the MTP and DL and the similarity in joint angles between the DL and CMJ. Therefore, the DL may be an optimal choice for athletes in jump-dependent sports, regardless of bar.

  19. Why are you draining your brain? Factors underlying decisions of graduating Lebanese medical students to migrate.

    Science.gov (United States)

    Akl, Elie A; Maroun, Nancy; Major, Stella; Afif, Claude; Chahoud, Bechara; Choucair, Jacques; Sakr, Mazen; Schünemann, Holger J

    2007-03-01

    In the context of a worldwide physician brain drain phenomenon, Lebanon has the highest emigration factor in the Middle East and North Africa. In this manuscript we aim to identify and develop a conceptual framework for the factors underlying the decisions of graduating Lebanese medical students to train abroad. We conducted two focus groups and seven semi-structured individual interviews with 23 students. In the deductive analysis (based on the push-pull theory), students reported push factors in Lebanon and pull factors abroad related to five dimensions. They focused predominantly on how training abroad provides them with a competitive advantage in an oversaturated Lebanese job market. An inductive analysis revealed the following emerging concepts: repel factors abroad and retain factors locally; societal expectations that students should train abroad; marketing of abroad training; and an established culture of migration. The marketing of abroad training and the culture of migration are prevalent in the academic institutions.

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

    International Nuclear Information System (INIS)

    Miyato, N.; Yagi, M.; Scott, B. D.

    2015-01-01

    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 is 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Miyato, N., E-mail: miyato.naoaki@jaea.go.jp; Yagi, M. [Japan Atomic Energy Agency, 2-116 Omotedate, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Scott, B. D. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany)

    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 is 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.

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

    Science.gov (United States)

    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 (ppush-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 (ppush-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.

  3. Combining Push Pull Tracer Tests and Microbial DNA and mRNA Analysis to Assess In-Situ Groundwater Nitrate Transformations

    Science.gov (United States)

    Henson, W.; Graham, W. D.; Huang, L.; Ogram, A.

    2015-12-01

    Nitrogen transformation mechanisms in the Upper Floridan Aquifer (UFA) are still poorly understood because of karst aquifer complexity and spatiotemporal variability in nitrate and carbon loading. Transformation rates have not been directly measured in the aquifer. This study quantifies nitrate-nitrogen transformation potential in the UFA using single well push-pull tracer injection (PPT) experiments combined with microbial characterization of extracted water via qPCR and RT-qPCR of selected nitrate reduction genes. Tracer tests with chloride and nitrate ± carbon were executed in two wells representing anoxic and oxic geochemical end members in a spring groundwater contributing area. A significant increase in number of microbes with carbon addition suggests stimulated growth. Increases in the activities of denitrification genes (nirK and nirS) as measured by RT-qPCR were not observed. However, only microbes suspended in the tracer were obtained, ignoring effects of aquifer material biofilms. Increases in nrfA mRNA and ammonia concentrations were observed, supporting Dissimilatory Reduction of Nitrate to Ammonia (DNRA) as a reduction mechanism. In the oxic aquifer, zero order nitrate loss rates ranged from 32 to 89 nmol /L*hr with no added carbon and 90 to 240 nmol /L*hr with carbon. In the anoxic aquifer, rates ranged from 18 to 95 nmol /L*hr with no added carbon and 34 to 207 nmol /L*hr with carbon. These loss rates are low; 13 orders of magnitude less than the loads applied in the contributing area each year, however they do indicate that losses can occur in oxic and anoxic aquifers with and without carbon. These rates may include, ammonia adsorption, uptake, or denitrification in aquifer material biofilms. Rates with and without carbon addition for both aquifers were similar, suggesting aquifer redox state and carbon availability alone are insufficient to predict response to nutrient additions without characterization of microbial response. Surprisingly, these

  4. Association of the Duration of Active Pushing With Obstetric Outcomes.

    Science.gov (United States)

    Grobman, William A; Bailit, Jennifer; Lai, Yinglei; Reddy, Uma M; Wapner, Ronald J; Varner, Michael W; Caritis, Steve N; Prasad, Mona; Tita, Alan T N; Saade, George; Sorokin, Yoram; Rouse, Dwight J; Blackwell, Sean C; Tolosa, Jorge E

    2016-04-01

    To estimate the associations between the duration of active pushing during the second stage of labor and maternal and neonatal outcomes. We performed an observational study in which data were obtained by trained abstractors from maternal and neonatal charts of deliveries at 25 hospitals over a 3-year period. In this secondary analysis, women with no prior cesarean delivery who had a term, singleton, cephalic gestation and reached complete dilation were analyzed. The duration of pushing, defined as the time from initiation of pushing to either vaginal delivery or the decision to proceed with a cesarean delivery, was determined. The primary maternal outcome was cesarean delivery and the primary neonatal outcome was a composite that included: mechanical ventilation, proven sepsis, brachial plexus palsy, clavicular fracture, skull fracture, other fracture, seizures, hypoxic-ischemic encephalopathy, or death. Nulliparous and parous women were analyzed separately in univariable and then multivariable analyses. A total of 53,285 women were analyzed. In both nulliparous and parous women, longer duration of pushing was associated with increased odds of both cesarean delivery and the neonatal adverse outcome composite. Nevertheless, even after 4 hours of pushing, approximately 78% of nulliparous women who continued with active pushing had a vaginal delivery and more than 97% did not have the composite adverse neonatal outcome. Similarly, after more than 2 hours of pushing, approximately 82% of parous women who continued active pushing delivered vaginally and more than 97% did not have the adverse neonatal outcome. A longer duration of pushing is associated with an increased relative risk, but small absolute difference in risk, of neonatal complications. Approximately 78% of nulliparous women delivered vaginally even after 4 hours of pushing.

  5. Single-well reactive tracer test and stable isotope analysis for determination of microbial activity in a fast hydrocarbon-contaminated aquifer

    International Nuclear Information System (INIS)

    Burbery, L.; Cassiani, G.; Andreotti, G.; Ricchiuto, T.; Semple, K.T.

    2004-01-01

    Single-well reactive tracer tests, such as the push-pull test are useful tools for characterising in-situ bioattenuation processes in contaminated aquifers. However, the analytical models that are used to interpret push-pull data may be over-simplified, and potentially overlook important processes responsible for the frequent discrepancy between predicted and observed results obtained from push-pull tests. In this study, the limitations underlying the push-pull test methodology were investigated and were supported with results from a push-pull test conducted in a sulphate-reducing aquifer contaminated by crude oil. Poor ( 20% mass recoveries were achieved. Push-pull test data collected from sulphate-reducing aquifers indicate that the assumption of a well-mixed batch reactor system is incorrect and that reaction rates obtained from push-pull tests in such systems may be affected by the extraction regime implemented. Evidence of microbial respiration of the reactive tracer was provided by stable sulphur isotope analysis, from which an isotope fractionation factor of +9.9±8.1%o was estimated. The stable isotope data support the argument that reaction rates calculated using push-pull tests are not uniformly distributed in space and time and are likely to be influenced by heterogeneities in the flow field. - Reaction rates calculated by push-pull tests are not uniformly distributed in time and space

  6. Friction Pull Plug and Material Configuration for Anti-Chatter Friction Pull Plug Weld

    Science.gov (United States)

    Littell, Justin Anderson (Inventor)

    2016-01-01

    A friction pull plug is provided for use in forming a plug weld in a hole in a material. The friction pull plug includes a shank and a series of three frustoconical sections. The relative sizes of the sections assure that a central one of the sections defines the initial contact point between the hole's sides. The angle defined by the central one of the sections reduces or eliminates chatter as the plug is pulled into the hole.

  7. Exercise-training intervention studies in competitive swimming.

    Science.gov (United States)

    Aspenes, Stian Thoresen; Karlsen, Trine

    2012-06-01

    Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three

  8. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INLAND NAVIGATION RULES INLAND RULES: INTERPRETATIVE RULES § 90.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and...

  9. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES 72 COLREGS: INTERPRETATIVE RULES § 82.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a...

  10. Human push capability.

    Science.gov (United States)

    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.

  11. Pull-pull position control of dual motor wire rope transmission.

    Science.gov (United States)

    Guo, Quan; Jiao, Zongxia; Yan, Liang; Yu, Qian; Shang, Yaoxing

    2016-08-01

    Wire rope transmission is very efficient because of the small total moving object mass. The wire rope could only transmit pulling force. Therefore it has to be kept in a tightened state during transmission; in high speed applications the dynamic performance depends on the rope's stiffness, which can be adjusted by the wire rope tension. To improve the system dynamic performance output, this paper proposes a novel pull-pull method based on dual motors connected by wire ropes, for precise, high speed position control applications. The method can regulate target position and wire rope tension simultaneously. Wire ropes remain in a pre-tightening state at all times, which prevents the influence of elasticity and reduces the position tracking error in the changing direction process. Simulations and experiments were conducted; the results indicate that both position precision and superior dynamic performance can be synchronously achieved. The research is relevant to space craft precision pointing instruments.

  12. Online video-based resistance training improves the physical capacity of junior basketball athletes.

    Science.gov (United States)

    Klusemann, Markus J; Pyne, David B; Fay, Tristan S; Drinkwater, Eric J

    2012-10-01

    Junior basketball athletes require a well-designed resistance training program to improve their physical development. Lack of expert supervision and resistance training in junior development pathways may be overcome by implementing an online video-based program. The aim of this study was to compare the magnitude of improvement (change) in physical performance and strength and functional movement patterns of junior basketball athletes using either a fully supervised or an online video-based resistance training program. Thirty-eight junior basketball athletes (males, n = 17; age, 14 ± 1 year; height, 1.79 ± 0.10 m; mass, 67 ± 12 kg; females, n = 21; age, 15 ± 1 year; height, 1.70 ± 0.07 m; mass, 62 ± 8 kg) were randomly assigned into a supervised resistance training group (SG, n = 13), video training group (VG, n = 13) or control group (CG, n = 12) and participated in a 6-week controlled experimental trial. Pre- and posttesting included measures of physical performance (20-m sprint, step-in vertical jump, agility, sit and reach, line drill, and Yo-Yo intermittent recovery level 1), strength (15 s push-up and pull-up), and functional movement screening (FMS). Both SG and VG achieved 3-5% ± 2-4% (mean ± 90% confidence limits) greater improvements in several physical performance measures (vertical jump height, 20-m sprint time, and Yo-Yo endurance performance) and a 28 ± 21% greater improvement in push-up strength compared with the CG. The SG attained substantially larger gains in FMS scores over both the VG (12 ± 10%) and CG (13 ± 8%). Video-based training appears to be a viable option to improve physical performance and strength in junior basketball athletes. Qualified supervision is recommended to improve functional movement patterns in junior athletes.

  13. Pengaruh Latihan Traditional Push Up, Plyometric Push Up, dan Incline Push Up Terhadap Kekuatan Otot Lengan, Power Otot Lengan, dan Daya Tahan Otot Lengan

    Directory of Open Access Journals (Sweden)

    Febriyan Dwi Cahyono

    2018-05-01

    Full Text Available Tujuan penelitian ini adalah untuk peningkatan performa fisik otot lengan siswa ekstrakulikuler putra SMAN 2 Lamongan yang memiliki kelemahan saat dilakukan evaluasi fisik. Empat puluh siswa sehat dengan melihat status gizi melalui indeks masa tubuh (IMT dipilih sesuai dengan kriteria dan dilakukan pretest dan pemeringkatan sehingga masuk dalam pengelompokan traditional push up, plyometric push up, incline push up dan kelompok kontrol. Push up 30 detik, push up 60 detik dan medicine ball test digunakan untuk mengukur peningkatan kinerja. Ketiga kelompok berpartisipasi dalam penelitian tiga hari dalam seminggu selama enam minggu dan menyelesaikan 18 sesi pelatihan, pada frekuensi 3 sesi per minggu. Hasil uji paired sample t-test dalam kelompok traditional push up menunjukkan pengaruh yang signifikan pada variabel kekuatan dan daya tahan, kelompok plyometric push up menunjukkan pengaruh yang signifikan pada variabel kekuatan dan power, dan kelompok incline push up menunjukkan pengaruh yang signifikan pada variabel kekuatan dan daya tahan.  Disimpulkan dari penelitian ini bahwa pelatihan traditional push up, plyometric push up dan incline push up ketiganya efektif untuk peningkatan kinerja tubuh bagian atas.

  14. Pulled elbow in children.

    Science.gov (United States)

    Yamanaka, Syunsuke; Goldman, Ran D

    2018-06-01

    Question Our practice is seeing children with relatively minor injuries to their elbows, with a history of "swinging" them when their hands are being held to cross the road. Nothing is usually found on a physical examination. I know that this is likely a "pulled elbow." Can we manage this in the clinic setting rather than sending the family to the emergency department? What would be the best course of action in the clinic setting? Answer Pulled elbow, also called nursemaid's elbow , is a radial head subluxation caused by axial traction or a sudden pull of the extended pronated arm, and it is a very common phenomenon. The practice of swinging children while holding their hands should be abandoned. In the case of pulled elbow, the child usually avoids moving the affected arm, holding it close to his or her body, without considerable pain, and no obvious swelling or deformity can be seen. While a fracture should be excluded, pulled elbow can usually be identified based on this presentation. The reduction procedure can easily be done in the office setting, with an 80% success rate and no complications. The hyperpronation maneuver (holding the elbow at 90° and then firmly pronating the wrist) to reduce pulled elbow has been found to be better than a supination-flexion maneuver (holding the elbow at 90° with one hand, supinating and flexing the elbow rapidly with the other) and should be exercised first. When 2 trials of reduction are unsuccessful, the child's arm should be splinted and the family should be sent for further evaluation. Copyright© the College of Family Physicians of Canada.

  15. Impact of Androstenone on Leash Pulling and Jumping Up in Dogs

    Directory of Open Access Journals (Sweden)

    Glenna Pirner

    2016-05-01

    Full Text Available Dogs are relinquished to shelters due to behavioral problems, such as leash pulling and jumping up. Interomones are chemical cues produced by one species that elicit a response in a different species. We reported earlier that androstenone, a swine sex pheromone, acts as an interomone to reduce barking in dogs. Here we report two models using 10 dogs/study: a dog jumping and a dog walking model. For the leash-pulling model, each time the dog pulled on the leash the walker either did nothing (NOT, or sprayed the dog with water (H2O, androstenone + water (ANH, androstenone 0.1 µg/mL (AND1, or androstenone 1.0 µg/mL (AND2. The number of pulls during each walk was counted. For the jumping up model, each time the dog jumped the researcher did nothing (NOT, or sprayed the dog with H2O, ANH, AND1, or AND2. The number of jumps and the time between jumps were recorded. In Study 1, ANH, AND1, and AND2 each reduced leash pulling more than NOT and H2O (p< 0.01. In Study 2, all treatments were effective in reducing jumping up behavior. Androstenone reduced jumping up, but not beyond that elicited by a spray of water alone. We conclude that androstenone in multiple delivery vehicles reduced leash pulling. The burst of air intended as a disruptive stimulus in the correction sprays may be too harsh for more sensitive dogs, and as such use of these sprays is cautioned in these animals. For other dogs, this interomone can be used to stop some behavior immediately or as a part of a training program to reduce undesirable behavior.

  16. Efficient {pi} electrons delocalization in prospective push-pull non-linear optical chromophore 4-[N,N-dimethylamino]-4'-nitro stilbene (DANS): A vibrational spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, T.; Hubert Joe, I. [Centre for Molecular and Biophysics Research, Department of Physics, Mar Ivanios College, Thiruvananthapuram 695 015, Kerala (India); Reghunadhan Nair, C.P. [Polymers and Special Chemicals Division, Vikram Sarabhai Space Centre, Thiruvananthapuram 695 022, Kerala (India); Jayakumar, V.S. [Centre for Molecular and Biophysics Research, Department of Physics, Mar Ivanios College, Thiruvananthapuram 695 015, Kerala (India)], E-mail: vsjk@vsnl.net

    2008-01-22

    A comprehensive investigation on the intramolecular charge transfer (ICT) of an efficient {pi}-conjugated potential push-pull NLO chromophore, 4-[N,N-dimethylamino]-4'-nitro stilbene (DANS), from a strong electron-donor group (dimethylamino-N(CH{sub 3}){sub 2}) to a strong electron-acceptor group (nitro-NO{sub 2}) through the {pi}-conjugated bridge (trans-stilbene) has been carried out from their vibrational spectra. The NIR FT-Raman and FT-IR spectra supported by the density functional theory (DFT) quantum chemical computations have been employed to analyze the effects of intramolecular charge transfer on the geometries and the vibrational modes contributing to the linear electro-optic effect of the organic NLO material. It has been observed that the changes in the endocyclic and exocyclic angles result from the charge-transfer interaction of the phenyl ring and the amino group in the electron-donor side of the NLO chromophore. The strongest vibrational modes contributing to the electro-optic effect have been identified and examined from the concurrent IR and Raman activation of {nu}(C=C/C-C) mode, ring C=C stretching modes, in-plane deformation modes, nitro modes and the umbrella mode of methyl groups. Furthermore, the splitting of the vinyl stretching modes and the electronic effects such as hyperconjugation and backdonation on the methyl hydrogen atoms causing the decrease of stretching frequencies and infrared intensities have also been analyzed in detail. The effect of frontier orbitals transition of electron density transfer and the influence of planarity between the phenyl rings of the stilbene moiety on the first hyperpolarizability have also been discussed.

  17. Comparison of the Hang High-Pull and Loaded Jump Squat for the Development of Vertical Jump and Isometric Force-Time Characteristics.

    Science.gov (United States)

    Oranchuk, Dustin J; Robinson, Tracey L; Switaj, Zachary J; Drinkwater, Eric J

    2017-04-15

    Weightlifting movements have high skill demands and require expert coaching. Loaded jumps have a comparably lower skill demand, but may be similarly effective for improving explosive performance. The purpose of this study was to compare vertical jump performance, isometric force, and rate of force development (RFD) following a ten-week intervention employing the hang high-pull (hang-pull) or trap-bar jump squat (jump-squat). Eighteen NCAA Division II swimmers (8 males, 10 females) with at least one year of resistance training experience volunteered to participate. Testing included the squat jump (SJ), countermovement jump (CMJ) and the isometric mid-thigh pull (IMTP). Vertical ground reaction forces were analyzed to obtain jump height and relative peak power. Relative peak force, peak RFD and relative force at five time bands were obtained from the IMTP. Subjects were randomly assigned to either a hang-pull (n = 9) or jump-squat (n = 9) training group and completed a ten-week, volume-equated, periodized training program. While there was a significant main effect of training for both groups, no statistically significant between-group differences were found (p ≥ 0.17) for any of the dependent variables. However, medium effect sizes in favor of the jump-squat training group were seen in SJ height (d = 0.56) and SJ peak power (d = 0.69). Loaded jumps seem equally effective as weightlifting derivatives for improving lower-body power in experienced athletes. Since loaded jumps require less skill and less coaching expertise than weightlifting, loaded jumps should be considered where coaching complex movements is difficult.

  18. Self-Induced Backaction Optical Pulling Force

    Science.gov (United States)

    Zhu, Tongtong; Cao, Yongyin; Wang, Lin; Nie, Zhongquan; Cao, Tun; Sun, Fangkui; Jiang, Zehui; Nieto-Vesperinas, Manuel; Liu, Yongmin; Qiu, Cheng-Wei; Ding, Weiqiang

    2018-03-01

    We achieve long-range and continuous optical pulling in a periodic photonic crystal background, which supports a unique Bloch mode with the self-collimation effect. Most interestingly, the pulling force reported here is mainly contributed by the intensity gradient force originating from the self-induced backaction of the object to the self-collimation mode. This force is sharply distinguished from the widely held conception of optical tractor beams based on the scattering force. Also, this pulling force is insensitive to the angle of incidence and can pull multiple objects simultaneously.

  19. Delayed pull-in transitions in overdamped MEMS devices

    Science.gov (United States)

    Gomez, Michael; Moulton, Derek E.; Vella, Dominic

    2018-01-01

    We consider the dynamics of overdamped MEMS devices undergoing the pull-in instability. Numerous previous experiments and numerical simulations have shown a significant increase in the pull-in time under DC voltages close to the pull-in voltage. Here the transient dynamics slow down as the device passes through a meta-stable or bottleneck phase, but this slowing down is not well understood quantitatively. Using a lumped parallel-plate model, we perform a detailed analysis of the pull-in dynamics in this regime. We show that the bottleneck phenomenon is a type of critical slowing down arising from the pull-in transition. This allows us to show that the pull-in time obeys an inverse square-root scaling law as the transition is approached; moreover we determine an analytical expression for this pull-in time. We then compare our prediction to a wide range of pull-in time data reported in the literature, showing that the observed slowing down is well captured by our scaling law, which appears to be generic for overdamped pull-in under DC loads. This realization provides a useful design rule with which to tune dynamic response in applications, including state-of-the-art accelerometers and pressure sensors that use pull-in time as a sensing mechanism. We also propose a method to estimate the pull-in voltage based only on data of the pull-in times.

  20. The Effect of Variation of Plyometric Push-Ups on Force-Application Kinetics and Perception of Intensity.

    Science.gov (United States)

    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 push-up exercises ([CMP] SCPu, KCPu, and DFPu) than squat push-up exercises ([SP] SSPu and KSPu). Furthermore, the flight time was greater (P push-up exercises and train athletes' muscle power by correctly interpreting GRF-based parameters. However, caution is required as some parameters had marginal absolute reliability.

  1. 10–25 GHz frequency reconfigurable MEMS 5-bit phase shifter using push–pull actuator based toggle mechanism

    International Nuclear Information System (INIS)

    Dey, Sukomal; Koul, Shiban K

    2015-01-01

    This paper presents a frequency tunable 5-bit true-time-delay digital phase shifter using radio frequency microelectromechanical system (RF MEMS) technology. The phase shifter is based on the distributed MEMS transmission line (DMTL) concept utilizing a MEMS varactor. The main source of frequency tuning in this work is a bridge actuation mechanism followed by capacitance variation. Two stages of actuation mechanisms (push and pull) are used to achieve a 2:1 tuning ratio. Accurate control of the actuation voltage between the pull to push stages contributes differential phase shift over the band of interest. The functional behavior of the push–pull actuation over the phase shifter application is theoretically established, experimentally investigated and validated with simulation. The phase shifter is fabricated monolithically using a gold based surface micromachining process on an alumina substrate. The individual primary phase-bits (11.25°/22.5°/45°/90°/180°) that are the fundamental building blocks of the complete 5-bit phase shifter are designed, fabricated and experimentally characterized from 10–25 GHz for specific applications. Finally, the complete 5-bit phase shifter demonstrates an average phase error of 4.32°, 2.8°, 1° and 1.58°, an average insertion loss of 3.76, 4.1, 4.2 and 4.84 dB and an average return loss of 11.7, 12, 14 and 11.8 dB at 10, 12, 17.2 and 25 GHz, respectively. To the best of the authors’ knowledge, this is the first reported band tunable stand alone 5-bit phase shifter in the literature which can work over the large spectrum for different applications. The total area of the 5-bit phase shifter is 15.6 mm 2 . Furthermore, the cold-switched reliability of the unit cell and the complete 5-bit MEMS phase shifter are extensively investigated and presented. (paper)

  2. Pengaruh Latihan Lari Zig-Zag, Lari Bolak-Balik, Push-Up dengan Pola Circuit Training Terhadap Kesegaran Jasmani Siswa Ekstrakurikuler Sepak Bola SMAN I Soa Tahun Ajaran 2015/2016

    Directory of Open Access Journals (Sweden)

    Wiljiwianus Primus Wio Bei

    2017-11-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui pengaruh latihan lari zig-zag,  lari bolak-balik, push-up dengan pola circuit training studi pada siswa ekstrakurikuler sepak bola SMAN 1 Soa. Penelitian ini adalah penelitian eksperimen dengan desain the static –group pretest – posttest design. Sampel penelitian ini sebanyak 40 orang terdiri atas 20 orang adalah kelompok eksperimen dan 20 orang kelompok kontrol yang diambil secara random. Untuk mengumpulkan data peningkatan Kesegaran Jasmani digunakan TKJI, kemudian data dianalisis dengan t-test. Hasil analisis menunjukan bahwa nilai thitung sebesar 3,5 lebih besar dari nilai ttabel 2,042 pada taraf signifikasi 5 % (α=0,05. Ini berarti ada perbedaan yang signifikan Kesegaran Jasmani antara kelompok eksperimen dan kelompok kontrol. Dengan demikian dapat disimpulkan bahwa latihan lari zig-zag, lari bolak-balik, push up dengan pola circuit training berpengaruh terhadap kesegaran jasmani pada siswa peserta ektrakurikuler sepak bola SMAN 1 Soa.

  3. Push Recovery for Humanoid Robot in Dynamic Environment and Classifying the Data Using K-Mean

    Directory of Open Access Journals (Sweden)

    Anubha Parashar

    2016-12-01

    Full Text Available Push recovery is prime ability that is essential to be incorporated in the process of developing a robust humanoid robot to support bipedalism. In real environment it is very essential for humanoid robot to maintain balance. In this paper we are generating a control system and push recovery controller for humanoid robot walking. We apply different kind of pushes to humanoid robot and the algorithm that can bring a change in the walking stage to sustain walking. The simulation is done in 3D environment using Webots. This paper describes techniques for feature selection to foreshow push recovery for hip, ankle and knee joint. We train the system by K-Mean algorithm and testing is done on crouch data and tested results are reported. Random push data of humanoid robot is collected and classified to see whether push lie in safer region and then tested on given proposed system.

  4. Training approach-avoidance of smiling faces affects emotional vulnerability in socially anxious individuals

    Science.gov (United States)

    Rinck, Mike; Telli, Sibel; Kampmann, Isabel L.; Woud, Marcella L.; Kerstholt, Merel; te Velthuis, Sarai; Wittkowski, Matthias; Becker, Eni S.

    2013-01-01

    Previous research revealed an automatic behavioral bias in high socially anxious individuals (HSAs): although their explicit evaluations of smiling faces are positive, they show automatic avoidance of these faces. This is reflected by faster pushing than pulling of smiling faces in an Approach-Avoidance Task (AAT; Heuer et al., 2007). The current study addressed the causal role of this avoidance bias for social anxiety. To this end, we used the AAT to train HSAs, either to approach smiling faces or to avoid them. We examined whether such an AAT training could change HSAs' automatic avoidance tendencies, and if yes, whether AAT effects would generalize to a new approach task with new facial stimuli, and to mood and anxiety in a social threat situation (a video-recorded self-presentation). We found that HSAs trained to approach smiling faces did indeed approach female faces faster after the training than HSAs trained to avoid smiling faces. Moreover, approach-faces training reduced emotional vulnerability: it led to more positive mood and lower anxiety after the self-presentation than avoid-faces training. These results suggest that automatic approach-avoidance tendencies have a causal role in social anxiety, and that they can be modified by a simple computerized training. This may open new avenues in the therapy of social phobia. PMID:23970862

  5. Training Approach-Avoidance of Smiling Faces Affects Emotional Vulnerability in Socially Anxious Individuals

    Directory of Open Access Journals (Sweden)

    Mike eRinck

    2013-08-01

    Full Text Available Previous research revealed an automatic behavioral bias in high socially anxious individuals (HSAs: Although their explicit evaluations of smiling faces are positive, they show automatic avoidance of these faces. This is reflected by faster pushing than pulling of smiling faces in an Approach-Avoidance Task (AAT; Heuer, Rinck, & Becker, 2007. The current study addressed the causal role of this avoidance bias for social anxiety. To this end, we used the AAT to train HSAs, either to approach smiling faces or to avoid them. We examined whether such an AAT training could change HSAs’ automatic avoidance tendencies, and if yes, whether AAT effects would generalize to a new approach task with new facial stimuli, and to mood and anxiety in a social threat situation (a video-recorded self-presentation. We found that HSAs trained to approach smiling faces did indeed approach female faces faster after the training than HSAs trained to avoid smiling faces. Moreover, approach-faces training reduced emotional vulnerability: It led to more positive mood and lower anxiety after the self-presentation than avoid-faces training. These results suggest that automatic approach-avoidance tendencies have a causal role in social anxiety, and that they can be modified by a simple computerized training. This may open new avenues in the therapy of social phobia.

  6. Multilevel push pull power converter

    DEFF Research Database (Denmark)

    2007-01-01

    A power converter for converting an input voltage (Vin) into an output voltage (Vout), comprising a first supply potential and a second supply potential established by the input voltage, and at least one primary winding having two terminals, a center tap arranged between the two terminals and con...

  7. Non-slipping domains of a pulled spool

    International Nuclear Information System (INIS)

    Wagner, Clemens; Vaterlaus, Andreas

    2014-01-01

    We have investigated the pulled spool by considering pulling angles up to 360 ∘ . Our focus was on downward pulling forces with pulling angles in the range of 180 ∘ to 360 ∘ . In this range we have found a domain of pulling angles where the spool never starts to slip independent of the strength of the pulling force. The size of the domain depends on the static friction coefficient and on the moment of inertia of the spool. The non-slipping domain is mainly formed around the critical angle where the static friction force becomes zero. For low static friction the non-slipping domain decays into two different domains. We have determined the limiting angles of the non-slipping domains and explored the transitions from a single domain to two separated domains in parameter space. (paper)

  8. A piezo motor based on a new principle with high output force, rigidity and integrity: The Tuna Drive

    Science.gov (United States)

    Liu, Xiaolong; Lu, Qingyou

    2012-11-01

    We present a linear piezoelectric motor as simple as one piezoelectric scanner tube (PST) spring-clamping a central shaft at both ends with roughly equal clamping forces. The clamping points are aligned with ±X electrodes at one end and ±Y electrodes at the other end. Thus, the ±X (or ±Y) push-pull motions of the PST can cause the push-pull motions of the clamping points on the shaft (called push-pull rubbing), which reduces the total dynamic friction force at one (or the other) end of the PST. This new piezo motor advances one step by fast push-pull rubbing at one end while slowly retracting the PST followed by fast push-pull rubbing at the other end while slowly elongating the PST. Apart from the obvious advantages of simplicity, rigidity, integrity, etc., we will also show that this motor can produce a large output force, which we believe is because of the huge drop of the clamping friction force when the push-pull rubbing occurs.

  9. Solar cell contact pull strength as a function of pull-test temperature

    Science.gov (United States)

    Yasui, R. K.; Berman, P. A.

    1972-01-01

    Four types of solar cell contacts were given pull-strength tests at temperatures between -173 and +165 C. Contacts tested were: (1) solder-coated titanium-silver contacts on n-p cells, (2) palladium-containing titanium-silver contacts on n-p cells, (3) titanium-silver contacts on 0.2-mm-thick n-p cells, and (4) solder-coated electroless-nickel-plated contacts on p-n cells. Maximum pull strength was demonstrated at temperatures significantly below the air mass zero cell equilibrium temperature of +60 C. At the lowest temperatures, the chief failure mechanism was silicon fracture along crystallographic planes; at the highest temperatures, it was loss of solder strength. In the intermediate temperatures, many failure mechanisms operated. Pull-strength tests give a good indication of the suitability of solar cell contact systems for space use. Procedures used to maximize the validity of the results are described.

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

    Science.gov (United States)

    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 push-ups (P 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.

  11. Implementing LEAN in the Supply Chain

    DEFF Research Database (Denmark)

    Bilberg, Arne

      An industrial co-operative project between a manufacturing company and a university demonstrates how a large scale project from idea to trained organisation was carried through. The order management process was redesigned from push to pull, and the planning activities were moved to the shop flo...

  12. Automatic control of oscillatory penetration apparatus

    Science.gov (United States)

    Lucon, Peter A

    2015-01-06

    A system and method for controlling an oscillatory penetration apparatus. An embodiment is a system and method for controlling a sonic drill having a displacement and an operating range and operating at a phase difference, said sonic drill comprising a push-pull piston and eccentrics, said method comprising: operating the push-pull piston at an initial push-pull force while the eccentrics are operated at a plurality of different operating frequencies within the operating range of the sonic drill and measuring the displacement at each operating frequency; determining an efficient operating frequency for the material being drilled and operating the eccentrics at said efficient operating frequency; determining the phase difference at which the sonic drill is operating; and if the phase difference is not substantially equal to minus ninety degrees, operating the push-pull piston at another push-pull force.

  13. Control of vertical posture while standing on a sliding board and pushing an object.

    Science.gov (United States)

    Lee, Yun-Ju; Chen, Bing; Liang, Jing-Nong; Aruin, Alexander S

    2018-03-01

    Voluntary pushing or translation perturbation of the support surface each induces a body perturbation that affects postural control. The objective of the study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments when pushing an object (that induces self-initiated perturbation) and standing on a sliding board (that induces translational perturbation). Thirteen healthy young participants were instructed to push a handle with both hands while standing on a sliding board that was either free to move in the anterior-posterior direction or stationary. Electromyographic activity (EMG) of trunk and lower extremity muscles, center of pressure (COP) displacements, and the forces exerted by the hand were recorded and analyzed during the APA and CPA phases. When the sliding board was free to move during pushing (translation perturbation), onsets of activity of ventral leg muscles and COP displacement were delayed as compared to pushing when standing on a stationary board. Moreover, magnitudes of shank muscle activity and the COP displacement were decreased. When pushing heavier weight, magnitudes of muscle activity, COP displacement, and pushing force increased. The magnitude of activity of the shank muscles during the APA and CPA phases in conditions with translational perturbation varied with the magnitude of the pushing weight. The outcome of the study suggests that the central nervous system prioritizes the pushing task while attenuates the source of additional perturbation induced by translation perturbation. These results could be used in the development of balance re-training paradigms involving pushing weight while standing on a sliding surface.

  14. Push Attack: Binding Virtual and Real Identities Using Mobile Push Notifications

    Directory of Open Access Journals (Sweden)

    Pierpaolo Loreti

    2018-01-01

    Full Text Available Popular mobile apps use push notifications extensively to offer an “always connected” experience to their users. Social networking apps use them as a real-time channel to notify users about new private messages or new social interactions (e.g., friendship request, tagging, etc.. Despite the cryptography used to protect these communication channels, the strict temporal binding between the actions that trigger the notifications and the reception of the notification messages in the mobile device may represent a privacy issue. In this work, we present the push notification attack designed to bind the physical owners of mobile devices with their virtual identities, even if pseudonyms are used. In an online attack, an active attacker triggers a push notification and captures the notification packets that transit in the network. In an offline attack, a passive attacker correlates the social network activity of a user with the received push notification. The push notification attack bypasses the standard ways of protecting user privacy based on the network layer by operating at the application level. It requires no additional software on the victim’s mobile device.

  15. Bench press and push-up at comparable levels of muscle activity results in similar strength gains.

    Science.gov (United States)

    Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C; Martin, Fernando; Tella, Victor; Andersen, Lars L

    2015-01-01

    Electromyography (EMG) exercise evaluation is commonly used to measure the intensity of muscle contraction. Although researchers assume that biomechanically comparable resistance exercises with similar high EMG levels will produce similar strength gains over the long term, no studies have actually corroborated this hypothesis. This study evaluated EMG levels during 6 repetition maximum (6RM) bench press and push-up, and subsequently performed a 5-week training period where subjects were randomly divided into 3 groups (i.e., 6RM bench press group, 6RM elastic band push-up group, or control group) to evaluate muscle strength gains. Thirty university students with advanced resistance training experience participated in the 2-part study. During the training period, exercises were performed using the same loads and variables that were used during the EMG data collection. At baseline, EMG amplitude showed no significant difference between 6RM bench press and band push-up. Significant differences among the groups were found for percent change (Δ) between pretest and posttest for 6RM (p = 0.017) and for 1 repetition maximum (1RM) (p bench press group and 6RM elastic band push-up group improved their 1RM and 6RM (Δ ranging from 13.65 to 22.21) tests significantly with similar gains, whereas control group remains unchanged. Thus, when the EMG values are comparable and the same conditions are reproduced, the aforementioned exercises can provide similar muscle strength gains.

  16. August A. Pulle. 1878-1955

    NARCIS (Netherlands)

    Lanjouw, J.

    1955-01-01

    On the 28th of February 1955 Prof. Dr A. A. Pulle died at Utrecht after a long and painful illness. August Adriaan Pulle was born on the 10th of January 1878 at Arnhem, where he also attended the primary and the secundary school. During the later years at the high school his interest in plants was

  17. The Efficacy of Wrestling-Style Compression Suits to Improve Maximum Isometric Force and Movement Velocity in Well-Trained Male Rugby Athletes.

    Science.gov (United States)

    McMaster, Daniel T; Beaven, Christopher M; Mayo, Brad; Gill, Nicholas; Hébert-Losier, Kim

    2017-01-01

    Purpose: The prevalence of compression garment (CG) use is increasing with athletes striving to take advantage of the purported benefits to recovery and performance. Here, we investigated the effect of CG on muscle force and movement velocity performance in athletes. Methods: Ten well-trained male rugby athletes wore a wrestling-style CG suit applying 13-31 mmHg of compressive pressure during a training circuit in a repeated-measures crossover design. Force and velocity data were collected during a 5-s isometric mid-thigh pull (IMTP) and repeated countermovement jump (CMJ), respectively; and time to complete a 5-m horizontal loaded sled push was also measured. Results: IMTP peak force was enhanced in the CG condition by 139 ± 142 N (effect size [ES] = 0.36). Differences in CMJ peak velocity (ES = 0.08) and loaded sled-push sprint time between the conditions were trivial (ES = -0.01). A qualitative assessment of the effects of CG wear suggested that the likelihood of harm was unlikely in the CMJ and sled push, while a beneficial effect in the CMJ was possible, but not likely. Half of the athletes perceived a functional benefit in the IMTP and CMJ exercises. Conclusion: Consistent with other literature, there was no substantial effect of wearing a CG suit on CMJ and sprint performance. The improvement in peak force generation capability in an IMTP may be of benefit to rugby athletes involved in scrummaging or lineout lifting. The mechanism behind the improved force transmission is unclear, but may involve alterations in neuromuscular recruitment and proprioceptive feedback.

  18. STRENGTH ANALYSIS METHODS OF CIRCULAR PULL BROACH COGS

    Directory of Open Access Journals (Sweden)

    Cosmin MIRIŢOIU

    2010-10-01

    Full Text Available A very big importance in a pull broach designing is represented by its mechanic computation, which trots out the pull broach resistance on various blank tooling, pull broach productivity and also the loadings which is subdued to and the stresses that appear during the chipping process. The pull broach geometric complexity leads to one difficulty concerning the resistance computing methods application (and implicitly, simplifying assumptions application. This present study presents a resistance computing of pull broach cogs, which dresses a circular hole trotting out more methods which can be used in this computing, and the teoretic aspects are then trotted out by an example of a numerical computation for a particular case.

  19. Customized Pull Systems for Single-Product Flow Lines

    NARCIS (Netherlands)

    Gaury, E.G.A.; Kleijnen, J.P.C.; Pierreval, H.

    1998-01-01

    Traditionally pull production systems are managed through classic control systems such as Kanban, Conwip, or Base stock, but this paper proposes ‘customized’ pull control. Customization means that a given production line is managed through a pull control system that in principle connects each stage

  20. Development of remote fuel pushing system in Reprocessing Plant, Tarapur

    International Nuclear Information System (INIS)

    Chandra, Munish; Coelho, G.; Kodilkar, S.S.; Mishra, A.K.; Bajpai, D.D.; Nair, M.K.T.

    1990-01-01

    Power Reactor Fuel Reprocessing Plant (PREFRE), Tarapur has been processing spent fuel arising from Pressurized Heavy Water Reactors for quite some time. The process adopted in the plant is purex process with chopleach head end treatment. The head end treatment involves loading of ten spent fuel bundles in the charging cask at a time in the fuel bay and aligning the cask with the transfer port and subsequently pushing all the ten bundles together into the fuel magazine. At present the fuel is pushed into the magazine manually. Since the ten bundles weigh approximately 200 Kg. and involves pushing of 9.4 meters length, the operation is carried out using stainless steel screwed pipes, in steps of five lengths. The entire operation requires a large number of trained skilled workers and is found to be tedious. To solve this problem a hydraulic cum pneumatic fuel pushing system has been designed, fabricated, tested and is in the process of installation in the fuel handling area. This paper describes various requirements, constraints and dimensional details arising in the incorporation of such a system to be back fitted in an existing plant, though many of these constraints can be avoided in future plants. Further, complete sequence of operations, technical specifications regarding the telescopic hydraulic power pack and associated controls incorporated in the system are highlighted. (author). 2 figs

  1. Particle Engulfment and Pushing

    Science.gov (United States)

    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.

  2. Push-pull effect on the geometrical, optical and charge transfer properties of disubstituted derivatives of mer-tris(4-hydroxy-1,5-naphthyridinato aluminum (mer-AlND3

    Directory of Open Access Journals (Sweden)

    Rao Joshi Laxmikanth

    2016-01-01

    Full Text Available To design innovative and novel optical materials with high mobility, two kinds of disubstituted derivatives for mer-tris(4-hydroxy-1,5-naphthyridinato aluminum (mer-AlND3 with push (EDG–pull (EWG substituents have been designed. The structures of mer-tris(8-EDG-2-EWG-4-hydroxy-1,5-naphthyridinato aluminum (type I and mer-tris(8-EWG-2-EDG-4-hydroxy-1,5-naphthyridinato aluminum (type II in the ground and first excited states have been optimized at the B3LYP/6-31G(D and CIS/6-31G(D level of theory, respectively. It can be seen from frontier molecular orbitals analysis, in all these complexes, the highest occupied molecular orbital (HOMO is localized on the pyridine-4-ol ring of A-ligand while lowest unoccupied molecular orbital (LUMO is on the pyridyl ring of B-ligand in ground state irrespective of electron donor/acceptor substitution present on the ligands similar to that of mer-tris(8-hydroxyquinoline aluminum (mer-Alq3 and parent mer-AlND3.The absorption and emission wavelengths have been evaluated at the TD-PBE0/6-31G(D level and it can be see that all the type I derivatives show blue shift while most of the type II derivatives show red shift compared to mer-AlND3. All the disubstituted complexes have showed hypsochromic shifts in both the absorption and emission spectra when compared with the calculated absorption and emission spectra respectively of mer-Alq3. It can be seen that the reorganization energies of some of the disubstituted derivatives are comparable with mer-Alq3 and these derivatives might be good candidates for emitting materials in OLED.

  3. Low-load bench press and push-up induce similar muscle hypertrophy and strength gain.

    Science.gov (United States)

    Kikuchi, Naoki; Nakazato, Koichi

    2017-06-01

    To investigate the effect of push-up training with a similar load of to 40% of 1- repetition maximumal (1RM) bench press on muscle hypertrophy and strength gain in men. Eighteen male participants (age, 20.2 ± 0.73 years, range: 19-22 years, height: 169.8 ± 4.4 cm, weight: 64.5 ± 4.7 kg) were randomly assigned to one of two experimental groups: bench press at 40%1RM (bench-press group, n = 9) or push-ups with position adjusted (e.g. kneeling) to the same load of bench-press 40%1RM (push-up group, n = 9), performed twice per week for 8 weeks. Muscle thickness at three sites (biceps, triceps, and pectoralis major), bench-press 1RM, maximum repetition at 40%1RM, and power output (medicine ball throw) were measured before and after the training period. Significant increases in 1RM and muscle thickness (triceps and pectoralis major) were observed in bench-press group (1RM, from 60.0 ± 12.1 kg to 65.0 ± 12.1 kg, p bench-press group (28.4 ± 3.3 mm to 31.5 ± 3.7 mm, p bench press is comparably effective for muscle hypertrophy and strength gain over an 8-week training period.

  4. Casing pull tests for directionally drilled environmental wells

    International Nuclear Information System (INIS)

    Staller, G.E.; Wemple, R.P.; Layne, R.R.

    1994-11-01

    A series of tests to evaluate several types of environmental well casings have been conducted by Sandia National Laboratories (SNL) and it's industrial partner, The Charles Machine Works, Inc. (CMW). A test bed was constructed at the CMW test range to model a typical shallow, horizontal, directionally drilled wellbore. Four different types of casings were pulled through this test bed. The loads required to pull the casings through the test bed and the condition of the casing material were documented during the pulling operations. An additional test was conducted to make a comparison of test bed vs actual wellbore casing pull loads. A directionally drilled well was emplaced by CMW to closely match the test bed. An instrumented casing was installed in the well and the pull loads recorded. The completed tests are reviewed and the results reported

  5. Casing pull tests for directionally drilled environmental wells

    Energy Technology Data Exchange (ETDEWEB)

    Staller, G.E.; Wemple, R.P. [Sandia National Labs., Albuquerque, NM (United States); Layne, R.R. [Charles Machine Works, Inc., Perry, OK (United States)

    1994-11-01

    A series of tests to evaluate several types of environmental well casings have been conducted by Sandia National Laboratories (SNL) and it`s industrial partner, The Charles Machine Works, Inc. (CMW). A test bed was constructed at the CMW test range to model a typical shallow, horizontal, directionally drilled wellbore. Four different types of casings were pulled through this test bed. The loads required to pull the casings through the test bed and the condition of the casing material were documented during the pulling operations. An additional test was conducted to make a comparison of test bed vs actual wellbore casing pull loads. A directionally drilled well was emplaced by CMW to closely match the test bed. An instrumented casing was installed in the well and the pull loads recorded. The completed tests are reviewed and the results reported.

  6. A study on metallic creep-fatigue interaction at elevated temperatures

    International Nuclear Information System (INIS)

    Ohnami, Masateru; Sakane, Masao

    1978-01-01

    In order to investigate the difference between the hold-time effect in push-pull low-cycle fatigue and that in torsional one, both types of strain controlled fatigue tests of SUS 316 stainless steel were performed at 600 0 C with or without hold-time. Significant difference between the push-pull and torsional fatigue test data on the basis of equivalent total strain range of Mises' type was not observed in terms of number of cycles to failure, number of cycles to crack initiation and crack propagation rate. More precisely speaking, however, the push-pull test had a larger hold-time effect on the failure life and on the crack behaviors than the torsional test in lower strain range. That is, slower crack propagation rate was observed in the push-pull test without hold-time than in torsional one, but crack propagation was observed in the push-pull test with hold-time. This crack behavior was discussed from the influence of stress triaxiality near the crack tip on the crack propagation rate and also from the effect of hydrostatic stress. (author)

  7. The Efficacy of Wrestling-Style Compression Suits to Improve Maximum Isometric Force and Movement Velocity in Well-Trained Male Rugby Athletes

    Directory of Open Access Journals (Sweden)

    Daniel T. McMaster

    2017-11-01

    Full Text Available Purpose: The prevalence of compression garment (CG use is increasing with athletes striving to take advantage of the purported benefits to recovery and performance. Here, we investigated the effect of CG on muscle force and movement velocity performance in athletes.Methods: Ten well-trained male rugby athletes wore a wrestling-style CG suit applying 13–31 mmHg of compressive pressure during a training circuit in a repeated-measures crossover design. Force and velocity data were collected during a 5-s isometric mid-thigh pull (IMTP and repeated countermovement jump (CMJ, respectively; and time to complete a 5-m horizontal loaded sled push was also measured.Results: IMTP peak force was enhanced in the CG condition by 139 ± 142 N (effect size [ES] = 0.36. Differences in CMJ peak velocity (ES = 0.08 and loaded sled-push sprint time between the conditions were trivial (ES = −0.01. A qualitative assessment of the effects of CG wear suggested that the likelihood of harm was unlikely in the CMJ and sled push, while a beneficial effect in the CMJ was possible, but not likely. Half of the athletes perceived a functional benefit in the IMTP and CMJ exercises.Conclusion: Consistent with other literature, there was no substantial effect of wearing a CG suit on CMJ and sprint performance. The improvement in peak force generation capability in an IMTP may be of benefit to rugby athletes involved in scrummaging or lineout lifting. The mechanism behind the improved force transmission is unclear, but may involve alterations in neuromuscular recruitment and proprioceptive feedback.

  8. Laparoscopically assisted anorectal pull-through for rectovestibular ...

    African Journals Online (AJOL)

    Laparoscopically assisted anorectal pull-through for rectovestibular fistula. Taha Alkhatrawi, Radi Elsherbini, Waheed Alturkistani. Abstract. Purpose Laparoscopically assisted anorectal pull-through (LAARP) has been described as an alternative to posterior sagittal anorectoplasty for the surgical treatment of rectourethral ...

  9. Effect of push handle height on net moments and forces on the musculoskeletal system during standardized wheelchair pushing tasks

    NARCIS (Netherlands)

    Van Der Woude, L H; Van Koningsbruggen, C M; Kroes, A L; Kingma, I

    1995-01-01

    The aim of this investigation was to analyze the external forces and biomechanical loading on the musculoskeletal system during wheelchair pushing, in relation to different push handle heights. In addition, recommendations for wheelchair pushing in accordance with push handle height are made. Eight

  10. Push piece for spent fuel elements magazine

    International Nuclear Information System (INIS)

    Griveau, R.; Kerlau, D.; Tucoulat, D.; Colas, J.; Pellier, R.

    1989-01-01

    The push piece permits the displacement of little section elements in a magazine of high section. At the end of cut, the push piece leans its flank against an auxiliary blank holder and the element is pushed by a paddle, the push piece being immobilized [fr

  11. Effects of a pushing intervention on pain, fatigue and birthing experiences among Taiwanese women during the second stage of labour.

    Science.gov (United States)

    Chang, Su-Chuan; Chou, Min-Min; Lin, Kuan-Chia; Lin, Lie-Chu; Lin, Yu-Lan; Kuo, Su-Chen

    2011-12-01

    To evaluate maternal labour pain, fatigue, duration of the second stage of labour, the women's bearing-down experiences and the newborn infant Apgar scores when spontaneous pushing is used in an upright position. Quasi-experimental study. Medical centre in Taichung, Taiwan. 66 Women giving birth at the hospital, with 33 primigravidas assigned to each group. During the second stage of labour, the women in the experimental group pushed from an upright position and were given support to push spontaneously; the women in the control group pushed from a supine position and were supported via Valsalva pushing. Pain scores were recorded at two evaluation time points: at 10 cm of cervical dilation and one hour after the first pain score evaluation. One to four hours after childbirth, the trained nurses collected the fatigue and pushing experience scores. The women in the experimental group had a lower pain index (5.67 versus 7.15, p = 0.01), lower feelings of fatigue post birth (53.91 versus 69.39, p pushing intervention during the second stage of labour lessened pain and fatigue, shortened the pushing time and enhanced the pushing experience. Pushing interventions can yield increased satisfaction levels for women giving birth. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. To push or not to push? Affective influences on moral judgment depend on decision frame.

    Science.gov (United States)

    Pastötter, Bernhard; Gleixner, Sabine; Neuhauser, Theresa; Bäuml, Karl-Heinz T

    2013-03-01

    People's moods can influence moral judgment. Such influences may arise because moods affect moral emotion, or because moods affect moral thought. The present study provides evidence that, at least in the footbridge dilemma, moods affect moral thought. The results of two experiments are reported in which, after induction of positive, negative, or neutral moods and presentation of the footbridge scenario, participants were asked one of two differentially framed closing questions. In the active frame, participants were asked whether they would be active and push the man, making thoughts about pushing accessible; in the passive frame, they were asked whether they would be passive and not push the man, making thoughts about not pushing accessible. The results show that affective influences on moral judgment depended on participants' decision frame. Compared to neutral moods, positive moods induced utilitarian responding - i.e., deciding to push - in the active decision frame, but induced nonutilitarian responding - i.e., deciding to not push - in the passive decision frame; in negative moods, exactly the opposite picture arose. The results suggest that people's moods affect moral judgment by conferring value on moral thought. Positive moods promote and negative moods inhibit accessible thoughts. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Analytical Model for Hook Anchor Pull-Out

    DEFF Research Database (Denmark)

    Brincker, Rune; Ulfkjær, Jens Peder; Adamsen, Peter

    1995-01-01

    A simple analytical model for the pull-out of a hook anchor is presented. The model is based on a simplified version of the fictitious crack model. It is assumed that the fracture process is the pull-off of a cone shaped concrete part, simplifying the problem by assuming pure rigid body motions...... allowing elastic deformations only in a layer between the pull-out cone and the concrete base. The derived model is in good agreement with experimental results, it predicts size effects and the model parameters found by calibration of the model on experimental data are in good agreement with what should...

  14. Analytical Model for Hook Anchor Pull-out

    DEFF Research Database (Denmark)

    Brincker, Rune; Ulfkjær, J. P.; Adamsen, P.

    A simple analytical model for the pull-out of a hook anchor is presented. The model is based on a simplified version of the fictitious crack model. It is assumed that the fracture process is the pull-off of a cone shaped concrete part, simplifying the problem by assuming pure rigid body motions...... allowing elastic deformations only in a layer between the pull-out cone and the concrete base. The derived model is in good agreement with experimental results, it predicts size effects and the model parameters found by calibration of the model on experimental data are in good agreement with what should...

  15. Reducing the Drag and Damage of a High-Speed Train by Analyzing and Optimizing its Boundary Layer Separation and Roll-up into Wake Vortices

    Science.gov (United States)

    Jiang, Chung-Hsiang; Marcus, Philip

    2012-11-01

    We present numerical calculations of the boundary layers and shed wake vortices behind several aerodynamic bodies and generic models of high-speed trains. Our calculations illustrate new visual diagnostics that we developed that clearly show where the separation of a boundary layer occurs and where, how, and with what angles (with respect to the stream-wise direction) the wake vortices form. The calculations also illustrate novel 3D morphing and mesh ``pushing and pulling'' techniques that allow us to change the shapes of aerodynamic bodies and models in a controlled and automated manner without spurious features appearing. Using these tools we have examined the patterns of the shed vortices behind generic bodies and trains and correlated them with the changes in the drag as well as with the effects of the shed vortices on the environment. In particular, we have applied these techniques to the end car of a next-generation, high-speed train in order to minimize the drag and to minimize the adverse effects of the shed vortices on the track ballast.

  16. Hair loss and hair-pulling in rhesus macaques (Macaca mulatta).

    Science.gov (United States)

    Lutz, Corrine K; Coleman, Kristine; Worlein, Julie; Novak, Melinda A

    2013-07-01

    Alopecia is a common problem in rhesus macaque colonies. A possible cause of this condition is hair-pulling; however the true relationship between hair-pulling and alopecia is unknown. The purpose of this study was to examine the relationship between hair loss and hair-pulling in 1258 rhesus macaques housed in 4 primate colonies across the United States. Alopecia levels ranged from 34.3% to 86.5% (mean, 49.3%) at the primate facilities. At facilities reporting a sex-associated difference, more female macaques were reported to exhibit alopecia than were males. In contrast, more males were reported to hair-pull. Animals reported to hair-pull were significantly more likely to have some amount of alopecia, but rates of hair-pulling were substantially lower than rates of alopecia, ranging from 0.6% to 20.5% (mean, 7.7%) of the populations. These results further demonstrate that hair-pulling plays only a small role in alopecia in rhesus macaques.

  17. Scapular kinematics and muscle activities during pushing tasks.

    Science.gov (United States)

    Huang, Chun-Kai; Siu, Ka-Chun; Lien, Hen-Yu; Lee, Yun-Ju; Lin, Yang-Hua

    2013-01-01

    Pushing tasks are functional activities of daily living. However, shoulder complaints exist among workers exposed to regular pushing conditions. It is crucial to investigate the control of shoulder girdles during pushing tasks. The objective of the study was to demonstrate scapular muscle activities and motions on the dominant side during pushing tasks and the relationship between scapular kinematics and muscle activities in different pushing conditions. Thirty healthy adults were recruited to push a four-wheel cart in six pushing conditions. The electromyographic signals of the upper trapezius (UT) and serratus anterior (SA) muscles were recorded. A video-based system was used for measuring the movement of the shoulder girdle and scapular kinematics. Differences in scapular kinematics and muscle activities due to the effects of handle heights and weights of the cart were analyzed using two-way ANOVA with repeated measures. The relationships between scapular kinematics and muscle activities were examined by Pearson's correlation coefficients. The changes in upper trapezius and serratus anterior muscle activities increased significantly with increased pushing weights in the one-step pushing phase. The UT/SA ratio on the dominant side decreases significantly with increased handle heights in the one-step pushing phase. The changes in upward rotation, lateral slide and elevation of the scapula decreased with increased pushing loads in the trunk-forward pushing phase. This study indicated that increased pushing loads result in decreased motions of upward rotation, lateral slide and elevation of the scapula; decreased handle heights result in relatively increased activities of the serratus anterior muscles during pushing tasks.

  18. Boris push with spatial stepping

    International Nuclear Information System (INIS)

    Penn, G; Stoltz, P H; Cary, J R; Wurtele, J

    2003-01-01

    The Boris push is commonly used in plasma physics simulations because of its speed and stability. It is second-order accurate, requires only one field evaluation per time step, and has good conservation properties. However, for accelerator simulations it is convenient to propagate particles in z down a changing beamline. A 'spatial Boris push' algorithm has been developed which is similar to the Boris push but uses a spatial coordinate as the independent variable, instead of time. This scheme is compared to the fourth-order Runge-Kutta algorithm, for two simplified muon beam lattices: a uniform solenoid field, and a 'FOFO' lattice where the solenoid field varies sinusoidally along the axis. Examination of the canonical angular momentum, which should be conserved in axisymmetric systems, shows that the spatial Boris push improves accuracy over long distances

  19. The influence of verbal training and visual feedback on manual wheelchair propulsion.

    Science.gov (United States)

    DeGroot, Keri K; Hollingsworth, Holly H; Morgan, Kerri A; Morris, Carrie L; Gray, David B

    2009-03-01

    To determine if verbal training with visual feedback improved manual wheelchair propulsion; to examine propulsion differences between an individual with paraplegia and an individual with tetraplegia. Quasi-experimental study: Nine manual wheelchair-using adults participated in propulsion assessments and training. Baseline propulsion performance was measured on several tasks on different surfaces. Participants were trained on a wheelchair treadmill with verbal and visual feedback to increase push length, reduce push frequency and to modify propulsion pattern. Handrim biomechanics were measured with an instrumented wheel. Changes in propulsion were assessed. Differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia were examined. Push length increased (p propulsion characteristics between a participant with paraplegia and a participant with tetraplegia. Verbal training may produce changes in push biomechanics of manual wheelchair users. Longer training periods may be needed to sustain propulsion changes. Findings from this study support other studies that have shown propulsion differences between people with tetraplegia and paraplegia. Propulsion training for populations with upper-extremity impairments warrants further study.

  20. A three-dimensional computerized isometric strength measurement system.

    Science.gov (United States)

    Black, Nancy L; Das, Biman

    2007-05-01

    The three-dimensional Computerized Isometric Strength Measurement System (CISMS) reliably and accurately measures isometric pull and push strengths in work spaces of paraplegic populations while anticipating comparative studies with other populations. The main elements of the system were: an extendable arm, a vertical supporting track, a rotating platform, a force transducer, stability sensors and a computerized data collection interface. The CISMS with minor modification was successfully used to measure isometric push-up and pull-down strengths of paraplegics and isometric push, pull, push-up and pull-down strength in work spaces for seated and standing able-bodied populations. The instrument has satisfied criteria of versatility, safety and comfort, ease of operation, and durability. Results are accurate within 2N for aligned forces. Costing approximately $1,500 (US) including computer, the system is affordable and accurate for aligned isometric strength measurements.

  1. A Comparison between Bench Press Throw and Ballistic Push-Up tests to assess upper-body power in trained individuals.

    Science.gov (United States)

    Bartolomei, Sandro; Nigro, Federico; Ruggeri, Sandro; Lanzoni, Ivan Malagoli; Ciacci, Simone; Merni, Franco; Sadres, Eliahu; Hoffman, Jay R; Semprini, Gabriele

    2018-03-06

    The purpose of the present study was to validate the ballistic push-up test performed with hands on a force plate (BPU) as a method to measure upper-body power. Twenty-eight experienced resistance trained men (age = 25.4 ± 5.2 y; body mass = 78.5 ± 9.0 kg; body height = 179.6 ± 7.8 cm) performed, two days apart, a bench press 1RM test and upper-body power tests. Mean power and peak power were assessed using the bench press throw test (BT) and the BPU test performed in randomized order. The area under the force/power curve (AUC) obtained at BT was also calculated. Power expressed at BPU was estimated using a time-based prediction equation. Mean force and the participant's body weight were used to predict the bench press 1RM. Pearson product moment correlations were used to examine relationships between the power assessment methods and between the predicted 1RM bench and the actual value. Large correlations (0.79; p bench and the 1RM predicted by the BPU. Results of the present study indicate that BPU represents a valid and reliable method to estimate the upper-body power in resistance-trained individuals.

  2. Evaluation of the Iron Horse Peformance Optimization Physical Training Program (IHPOP) in a Light Infantry Brigade, October 2010-April 2011

    Science.gov (United States)

    2014-06-19

    activities like excessive exercise or running long distances, r epetitive lifting/pulling/pushing objects, or repeatedly pitching a softball . 75... softball . 72. With these definitions in mind, have you had an injury during the past 6 months? If so, how many different times did you have an injury where

  3. Pull-Through Capacity in Plywood and OSB

    DEFF Research Database (Denmark)

    Munch-Andersen, Jørgen; Sørensen, John Dalsgaard

    The characteristic pull-through capacity of heads of nails and screws is needed to determine the rope effect for laterally loaded fasteners used to fix sheathing to timberframes. There is no values given in EN 1995 (Eurocode 5) but data for the pull through capacity of nail and screw heads has be...

  4. The effects of verbal information and approach-avoidance training on children's fear-related responses

    Science.gov (United States)

    Lester, Kathryn J.; Lisk, Stephen C.; Mikita, Nina; Mitchell, Sophie; Huijding, Jorg; Rinck, Mike; Field, Andy P.

    2015-01-01

    Background and objectives This study examined the effects of verbal information and approach-avoidance training on fear-related cognitive and behavioural responses about novel animals. Methods One hundred and sixty children (7–11 years) were randomly allocated to receive: a) positive verbal information about one novel animal and threat information about a second novel animal (verbal information condition); b) approach-avoidance training in which they repeatedly pushed away (avoid) or pulled closer (approach) pictures of the animals (approach-avoidance training), c) a combined condition in which verbal information was given prior to approach-avoidance training (verbal information + approach-avoidance training) and d) a combined condition in which approach-avoidance training was given prior to verbal information (approach-avoidance training + verbal information). Results Threat and positive information significantly increased and decreased fear beliefs and avoidance behaviour respectively. Approach-avoidance training was successful in training the desired behavioural responses but had limited effects on fear-related responses. Verbal information and both combined conditions resulted in significantly larger effects than approach-avoidance training. We found no evidence for an additive effect of these pathways. Limitations This study used a non-clinical sample and focused on novel animals rather than animals about which children already had experience or established fears. The study also compared positive information/approach with threat information/avoid training, limiting specific conclusions regarding the independent effects of these conditions. Conclusions The present study finds little evidence in support of a possible causal role for behavioural response training in the aetiology of childhood fear. However, the provision of verbal information appears to be an important pathway involved in the aetiology of childhood fear. PMID:25698069

  5. Giving an insulin injection

    Science.gov (United States)

    ... hand. The bubbles will float to the top. Push the bubbles back into the insulin bottle, then pull back to ... hand. The bubbles will float to the top. Push the bubbles back into the insulin bottle, then pull back to ...

  6. Pulled elbow in infancy: diagnostic role of imaging

    International Nuclear Information System (INIS)

    Scapinelli, Raffaele; Borgo, Andrea

    2005-01-01

    Purpose. Pulled elbow is a common injury in infancy. Typically the child, after a sudden pull, refuses to use the arm. The history and clinical findings are sufficient to make the diagnosis, and radiography or ultrasonography are not necessary. When imaging procedures are performed, a few small signs are useful to confirm the diagnosis of pulled elbow. Materials and methods. The authors reviewed the radiographic and ultrasonographic signs reported to be suggestive of pulled elbow (increased radio-condylar distance, increased radio-coronoid distance, proximal radio-ulnar diastasis, deviation of the radio-condylar line) and attempted to confirm their presence in children affected by this trauma. Results. Increased radio-condylar and radio-coronoid distance were present in 8 of 8 cases: proximal radio-ulnar diastasis and deviation of the radio-condylar line were inconsistently present. Ultrasonography gave contradictory results. Conclusions. In typical cases of pulled elbow, radiography or ultrasonography are not necessary for diagnosis and treatment. imaging procedures are recommended only in the case of non typical history, in the presence of deformity or traumatic skin lesions and in children over six years of age. Increased radio-coronoid distance on the affected side is the most frequent and visible sign, which can confirm the diagnosis of pulled elbow. Increased radio-condylar distance is also present, but it is not easy to visualize. Proximal radio-ulnar diastasis and deviation of the radio-condylar line are inconstant. Ultrasonography is difficult to standardize [it

  7. Steady-state Manoeuvring of a Generic ASD Tug in Escort Pull and Bow-rope Aided Push Operation

    Directory of Open Access Journals (Sweden)

    Jaroslaw Artyszuk

    2014-09-01

    Full Text Available This paper is devoted to expand the very promising research undertaken in the author's previous work, basically done on simplified modelling the escort push operation. Now, the other two modes of a tug's employment, as stated in the title, are covered. The special focus is again set on the indirect towing in that the towline force is much higher than the thruster force. The ratio of these two forces, referred to as the relative towing force (or amplification ratio is evaluated together with the hull drift angle and the thruster(-s angle for a given escort speed. This mutual relationship is known as the tug performance diagram. Although rather generic (container-type formulas are derived, they are supplied for exemplification purposes with simple, analytically given hull hydrodynamic forces. The aim is also here to provide a basis for further sensitivity analysis of the model and possible improvement/optimisation to the tug design. The obtained charts also could serve as rough and clear guidance for towmasters while escorting.

  8. [Design on tester of pull-out force for orthodontic micro implant].

    Science.gov (United States)

    Su, He; Wu, Pei; Wang, Huiyuan; Chen, Yan; Bao, Xuemei

    2013-09-01

    A special device for measuring the pull-out force of orthodontic micro implant was designed, which has the characteristics of simple construction and easy operation, and can be used to detect the pull-out-force of orthodontic micro implant. The tested data was stored and analyzed by a computer, and as the results, the pull-out-force curve, maximum pull-out force as well as average pull-out force were outputted, which was applied in analyzing or investigating the initial stability and immediate loading property of orthodontic micro implant.

  9. Virtual reality lead extraction as a method for training new physicians: a pilot study.

    Science.gov (United States)

    Maytin, Melanie; Daily, Thomas P; Carillo, Roger G

    2015-03-01

    It is estimated that the demand for transvenous lead extraction (TLE) has reached an annual extraction rate of nearly 24,000 patients worldwide. Despite technologic advances, TLE still has the potential for significant morbidity and mortality. Complication rates with TLE directly parallel operator experience. However, obtaining adequate training during and postfellowship can be difficult. Given the potential for catastrophic complications and the steep learning curve (up to 300 cases) associated with this procedure, we sought to validate a virtual reality (VR) lead extraction simulator as an innovative training and evaluation tool for physicians new to TLE. We randomized eight electrophysiology fellows to VR simulator versus conventional training. We compared procedural skill competency between the groups using simulator competency, tactile measurements, markers of proficiency and attitudes, and cognitive abilities battery. Practical skills and simulator complications differed significantly between the VR simulator and conventional training groups. The VR simulator group executed patient preparation and procedure performance better than the conventional group (P training experienced a simulator complication (two superior vena cava [SVC] tears, three right ventricle [RV] avulsions) versus one fellow in the VR simulator group (one SVC tear) (P = 0.02). Tactile measurements revealed a trend toward excess pushing versus pulling forces among the conventionally trained group. The time for lead removal was also significantly higher in the conventional training group (12.46 minutes vs 5.54 minutes, P = 0.02). There was no significant difference in baseline or posttraining cognitive ability. We contend that the implementation of alternative training tools such as a VR simulation model will improve physician training and allow for an innovative pathway to assess the achievement of competency. ©2014 Wiley Periodicals, Inc.

  10. Volunteer tourists' motivations for choosing homestay in the Kumasi Metropolis of Ghana

    Directory of Open Access Journals (Sweden)

    Elizabeth Agyeiwaah

    2013-01-01

    Full Text Available Volunteer tourists’ motivations for choosing homestay accommodation have received little attention from researchers. The objective of this research was to explore the push and pull factors that account for volunteer tourists’ choice of homestay in the Kumasi Metropolis of Ghana. Insights gained from this study will inure better understanding of volunteer tourists’ behaviour to ensure appropriate service delivery by homestay providers. With the help of the "Push and Pull" motivation model by Dann (1977, the findings indicated two main push factors: socio-cultural immersion and economic value; and pull factors: environmental sensitiveness and community service and development. The study found that the most important push and pull factors as perceived by volunteers to Ghana are socio-cultural immersion and environmental sensitiveness. The study confirms the supporting role of homestay for volunteer tourists to Ghana. In the end, the implications of this study are discussed.

  11. The effects of verbal information and approach-avoidance training on children's fear-related responses.

    Science.gov (United States)

    Lester, Kathryn J; Lisk, Stephen C; Mikita, Nina; Mitchell, Sophie; Huijding, Jorg; Rinck, Mike; Field, Andy P

    2015-09-01

    This study examined the effects of verbal information and approach-avoidance training on fear-related cognitive and behavioural responses about novel animals. One hundred and sixty children (7-11 years) were randomly allocated to receive: a) positive verbal information about one novel animal and threat information about a second novel animal (verbal information condition); b) approach-avoidance training in which they repeatedly pushed away (avoid) or pulled closer (approach) pictures of the animals (approach-avoidance training), c) a combined condition in which verbal information was given prior to approach-avoidance training (verbal information + approach-avoidance training) and d) a combined condition in which approach-avoidance training was given prior to verbal information (approach-avoidance training + verbal information). Threat and positive information significantly increased and decreased fear beliefs and avoidance behaviour respectively. Approach-avoidance training was successful in training the desired behavioural responses but had limited effects on fear-related responses. Verbal information and both combined conditions resulted in significantly larger effects than approach-avoidance training. We found no evidence for an additive effect of these pathways. This study used a non-clinical sample and focused on novel animals rather than animals about which children already had experience or established fears. The study also compared positive information/approach with threat information/avoid training, limiting specific conclusions regarding the independent effects of these conditions. The present study finds little evidence in support of a possible causal role for behavioural response training in the aetiology of childhood fear. However, the provision of verbal information appears to be an important pathway involved in the aetiology of childhood fear. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Characteristics and phenomenology of hair-pulling: an exploration of subtypes.

    Science.gov (United States)

    du Toit, P L; van Kradenburg, J; Niehaus, D J; Stein, D J

    2001-01-01

    This study was designed to detail the demographic and phenomenological features of adult chronic hair-pullers. Key possible subtypes were identified a priori. On the basis of the phenomenological data, differences between the following possible subtypes were investigated: hair-pullers with and without DSM-IV trichotillomania (TTM), oral habits, automatic versus focused hair-pulling, positive versus negative affective cues prior to hair-pulling, comorbid self-injurious habits, obsessive-compulsive disorder (OCD), and tics. Forty-seven participants were drawn from an outpatient population of chronic adult hair-pullers. A structured interview that focused on hair-pulling and associated behaviors was administered to participants. Six of the participants (12.8%) were male, and 41 (87.7%) were female. A large number of hair-pullers (63.8%) had comorbid self-injurious habits. A greater proportion of male hair-pullers had comorbid tics when compared with females. Certain subgroups of chronic hair-pullers (e.g., hairpullers with or without automatic/focused hair-pulling, comorbid self-injurious habits, and oral habits) were found to differ on a number of phenomenological and hair-pulling characteristics. However, differences between other possible subgroups (e.g., hair-pullers with or without DSM-IV TTM, comorbid OCD, and negative versus positive affective cues) may reflect greater severity in hair-pulling symptomatology rather than distinct subtypes of chronic hair-pulling. The findings of the present study also indicated that chronic hair-pulling (even in cases where DSM-IV criteria for TTM were not met) has a significant impact on quality of life. The present study provided limited support for the existence of possible subtypes of chronic hair-pulling. Recommendations are made for further investigations into such subtypes. Copyright 2001 by W.B. Saunders Company

  13. Take the "C" Train

    Science.gov (United States)

    Lawton, Rebecca

    2008-01-01

    In this essay, the author recalls several of her experiences in which she successfully pulled her boats out of river holes by throwing herself to the water as a sea-anchor. She learned this trick from her senior guides at a spring training. Her guides told her, "When you're stuck in a hole, take the "C" train."" "Meaning?" The author asked her…

  14. Two-Man Bobsled Push Start Analysis

    Directory of Open Access Journals (Sweden)

    Lopes Alexandre Dias

    2016-04-01

    Full Text Available The importance of push start times on bobsled performance was evidenced by some studies, but at this moment there is no article to the authors’ knowledge that describes the bobsled push start. Thus, the objectives of this study were to describe the two-man bobsled push start, analyze the differences between teams, and estimate the most important variable analyzed. We hypothesized that the pilot and brakeman athletes’ movement patterns during a bobsled pushing start can be described. The images used in this study were obtained during the men’s two-man XIV World Championship of Bobsled (2004. Fifteen best teams participating in the championship were recorded, and four start runs for each team were analyzed. The videos were captured by two digital video cameras. The pilot athletes were analyzed during the moment that they touched the lateral push bar of the sled, and the brakemen were analyzed during the first take-off and first landing. The teams were pooled in three groups of five teams using the final ranking of pushing time. We concluded that there was a distinct pattern movement for pilots and brakemen. The initial position of the majority of the pilots was localized slightly behind the bar. After touching the lateral bar, the pilots remained in a semi-squat position, pushing the sled forward in a pattern of marching movement. All brakemen used the board attached to the track as a support for both feet at the start. The brakeman gave the greatest contribution to break the inertia of the sled. There was no significant difference of movement between the three groups analyzed for the pilot and the brakeman.

  15. Postural Responses to a Suddenly Released Pulling Force in Older Adults with Chronic Low Back Pain: An Experimental Study.

    Directory of Open Access Journals (Sweden)

    Pei-Yun Lee

    Full Text Available Chronic low back pain (CLBP, one of the most common musculoskeletal conditions in older adults, might affect balance and functional independence. The purpose of this study was to investigate the postural responses to a suddenly released pulling force in older adults with and without CLBP. Thirty community-dwelling older adults with CLBP and 26 voluntary controls without CLBP were enrolled. Participants were required to stand on a force platform while, with one hand, they pulled a string that was fastened at the other end to a 2-kg or to a 4-kg force in the opposite direction at a random order. The number of times the participants lost their balance and motions of center of pressure (COP when the string was suddenly released were recorded. The results demonstrated that although the loss of balance rates for each pulling force condition did not differ between groups, older adults with CLBP had poorer postural responses: delayed reaction, larger displacement, higher velocity, longer path length, and greater COP sway area compared to the older controls. Furthermore, both groups showed larger postural responses in the 4-kg pulling force condition. Although aging is generally believed to be associated with declining balance and postural control, these findings highlight the effect of CLBP on reactive balance when responding to an externally generated force in an older population. This study also suggests that, for older adults with CLBP, in addition to treating them for pain and disability, reactive balance evaluation and training, such as reaction and movement strategy training should be included in their interventions. Clinicians and older patients with CLBP need to be made aware of the significance of impaired reactive balance and the increased risk of falls when encountering unexpected perturbations.

  16. Pull remanufacturing: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Levine, L.O.

    1992-09-01

    This paper describes how pull production methods have been applied to a manual transmission remanufacturing line at Tooele Army Depot in Utah. The paper emphasizes techniques for linking the control of disassembly and cleaning operations to the repair and assembly portions of the production system (PP&C). The primary objective is to show that production planning and control can be simplified when pull mechanisms are combined with shop floor improvements. One approach to applying MRP II to remanufacturing is to use a separate production schedule for the disassembly and assembly portions of the operation. This approach is primarily needed when managing the delivery and inventory of cores is critical to the successful operation of a remanufacturing organization. Because Army depots frequently have an adequate inventory of cores on hand (somewhere on-site), this requirement is usually less significant. Therefore, it is possible to eliminate the use of a master production schedule for disassembly and rely on pull linkages from the repair and assembly operations to control the activity of the disassembly and cleaning operations. In remanufacturing environments having multiple products and adequate buffers of core inventory, effective coordination of disassembly and cleaning functions with assembly production requirements becomes a key production control issue.

  17. Pull remanufacturing: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Levine, L.O.

    1992-09-01

    This paper describes how pull production methods have been applied to a manual transmission remanufacturing line at Tooele Army Depot in Utah. The paper emphasizes techniques for linking the control of disassembly and cleaning operations to the repair and assembly portions of the production system (PP C). The primary objective is to show that production planning and control can be simplified when pull mechanisms are combined with shop floor improvements. One approach to applying MRP II to remanufacturing is to use a separate production schedule for the disassembly and assembly portions of the operation. This approach is primarily needed when managing the delivery and inventory of cores is critical to the successful operation of a remanufacturing organization. Because Army depots frequently have an adequate inventory of cores on hand (somewhere on-site), this requirement is usually less significant. Therefore, it is possible to eliminate the use of a master production schedule for disassembly and rely on pull linkages from the repair and assembly operations to control the activity of the disassembly and cleaning operations. In remanufacturing environments having multiple products and adequate buffers of core inventory, effective coordination of disassembly and cleaning functions with assembly production requirements becomes a key production control issue.

  18. Cyclic deformation behaviour of quenched and tempered 42CrMo4 (AISI 4140) at two-block push-pull-loading; Zum Wechselverformungsverhalten von verguetetem 42CrMo4 bei zweistufiger Zug-Druck-Beanspruchung

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, V. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Werkstoffkunde 1; Lang, K.-H.; Voehringer, O.; Macherauch, E.

    1998-11-01

    The behaviour of steels in the course of two- and multi-block cyclic loading has been investigated up to now almost exclusively regarding the fatigue life. According to this, only a few papers exist, dealing with the cyclic deformation behaviour at two- and multi-block-push-pull-loading. Therefore, in stress- and total strain-controlled experiments with a single change of the amplitude (two-block-experiments) and multiple changes between two blocks of different lengths and amplitudes (multi-block-experiments) the cyclic deformation processes have been investigated for the quenched and tempered steel grade 42 CrMo 4 (equivalent to AISI 4140). Using the data of stress- and strain-Woehler-curves determined in usual fatigue tests, damages defined according to Miner`s rule were adjoined to the blocks. The Miner-damages at failure observed in the two-block-experiments with changes from high to low amplitudes were smaller than one and at inverse changes of amplitudes larger than one. In contrast to this, in multi-block-experiments no universally valid correlations were observed between the Miner-damages at failure and the test-parameters applied. At all tests cyclic work-softening was observed as in single-step-experiments. However, work-softening processes at high amplitude loadings yield to much larger plastic strain amplitudes after changing to smaller amplitudes than in single-step tests. Contrarily, in multi-block-tests work-softening at higher amplitude loadings reduces with decreasing block-length and increasing portion of the blocks with the smaller amplitude. This is attributed to effects of static strain-ageing. Total-strain-controlled two-block cyclic deformation experiments yield to similar effects as in stress-controlled tests. 18 refs.

  19. 'Mister Badger' Pushing Mars Rock

    Science.gov (United States)

    1976-01-01

    Viking's soil sampler collector arm successfully pushed a rock on the surface of Mars during the afternoon of Friday, October 8. The irregular-shaped rock was pushed several inches by the Lander's collector arm, which displaced the rock to the left of its original position, leaving it cocked slightly upward. Photographs and other information verified the successful rock push. Photo at left shows the soil sampler's collector head pushing against the rock, named 'Mister Badger' by flight controllers. Photo at right shows the displaced rock and the depression whence it came. Part of the soil displacement was caused by the collector s backhoe. A soil sample will be taken from the site Monday night, October 11. It will then be delivered to Viking s organic chemistry instrument for a series of analyses during the next few weeks. The sample is being sought from beneath a rock because scientists believe that, if there are life forms on Mars, they may seek rocks as shelter from the Sun s intense ultraviolet radiation.

  20. Delayed versus immediate pushing in second stage of labor.

    Science.gov (United States)

    Kelly, Mary; Johnson, Eileen; Lee, Vickie; Massey, Liz; Purser, Debbie; Ring, Karen; Sanderson, Stephanye; Styles, Juanita; Wood, Deb

    2010-01-01

    Comparison of two different methods for management of second stage of labor: immediate pushing at complete cervical dilation of 10 cm and delayed pushing 90 minutes after complete cervical dilation. This study was a randomized clinical trial in a labor and delivery unit of a not-for-profit community hospital. A sample of 44 nulliparous mothers with continuous epidural anesthesia were studied after random assignment to treatment groups. Subjects were managed with either immediate or delayed pushing during the second stage of labor at the time cervical dilation was complete. The primary outcome measure was the length of pushing during second stage of labor. Secondary outcomes included length of second stage of labor, maternal fatigue and perineal injuries, and fetal heart rate decelerations. Two-tailed, unpaired Student's t-tests and Chi-square analysis were used for data analysis. Level of significance was set at p pushing; N = 16 delayed pushing). The delayed pushing group had significantly shorter amount of time spent in pushing compared with the immediate pushing group (38.9 +/- 6.9 vs. 78.7 +/- 7.9 minutes, respectively, p = .002). Maternal fatigue scores, perineal injuries, and fetal heart rate decelerations were similar for both groups. Delaying pushing for up to 90 minutes after complete cervical dilation resulted in a significant decrease in the time mothers spent pushing without a significant increase in total time in second stage of labor.In clinical practice, healthcare providers sometimes resist delaying the onset of pushing after second stage of labor has begun because of a belief it will increase labor time. This study's finding of a 51% reduction in pushing time when mothers delay pushing for up to 90 minutes, with no significant increase in overall time for second stage of labor, disputes that concern.

  1. Accurate electrostatic and van der Waals pull-in prediction for fully clamped nano/micro-beams using linear universal graphs of pull-in instability

    Science.gov (United States)

    Tahani, Masoud; Askari, Amir R.

    2014-09-01

    In spite of the fact that pull-in instability of electrically actuated nano/micro-beams has been investigated by many researchers to date, no explicit formula has been presented yet which can predict pull-in voltage based on a geometrically non-linear and distributed parameter model. The objective of present paper is to introduce a simple and accurate formula to predict this value for a fully clamped electrostatically actuated nano/micro-beam. To this end, a non-linear Euler-Bernoulli beam model is employed, which accounts for the axial residual stress, geometric non-linearity of mid-plane stretching, distributed electrostatic force and the van der Waals (vdW) attraction. The non-linear boundary value governing equation of equilibrium is non-dimensionalized and solved iteratively through single-term Galerkin based reduced order model (ROM). The solutions are validated thorough direct comparison with experimental and other existing results reported in previous studies. Pull-in instability under electrical and vdW loads are also investigated using universal graphs. Based on the results of these graphs, non-dimensional pull-in and vdW parameters, which are defined in the text, vary linearly versus the other dimensionless parameters of the problem. Using this fact, some linear equations are presented to predict pull-in voltage, the maximum allowable length, the so-called detachment length, and the minimum allowable gap for a nano/micro-system. These linear equations are also reduced to a couple of universal pull-in formulas for systems with small initial gap. The accuracy of the universal pull-in formulas are also validated by comparing its results with available experimental and some previous geometric linear and closed-form findings published in the literature.

  2. COMPLEX SIMULATION MODEL OF TRAIN BREAKING-UP PROCESS AT THE HUMPS

    Directory of Open Access Journals (Sweden)

    E. B. Demchenko

    2015-11-01

    Full Text Available Purpose. One of the priorities of station sorting complex functioning improvement is the breaking-up process energy consumptions reduction, namely: fuel consumption for train pushing and electric energy consumption for cut braking. In this regard, an effective solution of the problem of energy consumption reduction at breaking-up subsystem requires a comprehensive handling of train pushing and cut rolling down processes. At the same time, the analysis showed that the current task of pushing process improvement and cut rolling down effectiveness increase are solved separately. To solve this problem it is necessary to develop the complex simulation model of train breaking up process at humps. Methodology. Pushing process simulation was done based on adapted under the shunting conditions traction calculations. In addition, the features of shunting locomotives work at the humps were taken into account. In order to realize the current pushing mode the special algorithm of hump locomotive controlling, which along with the safety shunting operation requirements takes into account behavioral factors associated with engineer control actions was applied. This algorithm provides train smooth acceleration and further movement with speed, which is close to the set speed. Hump locomotive fuel consumptions were determined based on the amount of mechanical work performed by locomotive traction. Findings. The simulation model of train pushing process was developed and combined with existing cut rolling down model. Cut initial velocity is determined during simulation process. The obtained initial velocity is used for further cut rolling process modeling. In addition, the modeling resulted in sufficiently accurate determination of the fuel rates consumed for train breaking-up. Originality. The simulation model of train breaking-up process at the humps, which in contrast to the existing models allows reproducing complexly all the elements of this process in detail

  3. Fixing Affordability: An Approach for Advancing Federalism in the Modern Era. State-Federal Partnerships in Postsecondary Education

    Science.gov (United States)

    Cooper, Michelle Asha

    2016-01-01

    There is a constant push and pull between state and the federal governments to find the right balance of federalism. By applying this "push-pull" framework to higher education, this brief looks at past policy interventions and how this framework can help to understand the free college movement.

  4. Initial atomic coherences and Ramsey frequency pulling in fountain clocks

    Science.gov (United States)

    Gerginov, Vladislav; Nemitz, Nils; Weyers, Stefan

    2014-09-01

    In the uncertainty budget of primary atomic cesium fountain clocks, evaluations of frequency-pulling shifts of the hyperfine clock transition caused by unintentional excitation of its nearby transitions (Rabi and Ramsey pulling) have been based so far on an approach developed for cesium beam clocks. We re-evaluate this type of frequency pulling in fountain clocks and pay particular attention to the effect of initial coherent atomic states. We find significantly enhanced frequency shifts caused by Ramsey pulling due to sublevel population imbalance and corresponding coherences within the state-selected hyperfine component of the initial atom ground state. Such shifts are experimentally investigated in an atomic fountain clock and quantitative agreement with the predictions of the model is demonstrated.

  5. Understanding Why Students Drop Out of High School, According to Their Own Reports

    Directory of Open Access Journals (Sweden)

    Jonathan Jacob Doll

    2013-10-01

    Full Text Available Research on school dropout extends from early 20th-century pioneers until now, marking trends of causes and prevention. However, specific dropout causes reported by students from several nationally representative studies have never been examined together, which, if done, could lead to a better understanding of the dropout problem. Push, pull, and falling out factors provide a framework for understanding dropouts. Push factors include school-consequence on attendance or discipline. Pull factors include out-of-school enticements like jobs and family. Finally, falling out factors refer to disengagement in students not caused by school or outside pulling factors. Since 1966, most nationally representative studies depicted pull factors as ranking the highest. Also, administrators in one study corroborated pull out factors for younger dropouts, not older ones, while most recent research cites push factors as highest overall. One rationale for this change is a response to rising standards from No Child Left Behind (NCLB, which can be ultimately tested only by future dropout research.

  6. Novel silicone compatible cross-linkers for controlled functionalization of PDMS networks

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Daugaard, Anders Egede; Hvilsted, Søren

    2013-01-01

    . In order to improve the dielectric properties of PDMS a novel system is developed where push-pull dipoles are grafted to a new silicone compatible cross-linker. The grafted cross-linkers are prepared by reaction of two different push-pull dipole alkynes as well as a fluorescent alkyne with the new azide...

  7. Superconducting push-pull flux quantum logic circuits

    International Nuclear Information System (INIS)

    Murphy, J.H.; Daniel, M.R.; Przybysz, J.X.

    1993-01-01

    A superconducting digital logic circuit is described comprising: a first circuit branch including first and second Josephson junctions electrically connected in series with each other; means for applying a positive bias voltage to a first end of said circuit branch; means for applying a negative bias voltage to a second end of said circuit branch; means for applying a first dual polarity input voltage signal to a first node in said circuit branch; and means for extracting a first output voltage signal from said first node in said circuit branch

  8. Technology Push / Market Pull Indicators in Healthcare

    Energy Technology Data Exchange (ETDEWEB)

    Nelhans, G.

    2016-07-01

    Healthcare and life sciences are among the most important drivers which form the present-day landscape of science and technology in general. A whole range of emerging areas of research and disruptive technologies are related to healthcare. The applied nature of such areas of research makes it important to specify indicators which describe these areas not only from R&D, but also from user need side. We analyze the content of domain-specific social media and online consulting services in healthcare with the help of semantic technologies in order to extract widespread and emerging user needs. We will map the corresponding topics on the agenda of scientific papers in healthcare. Understanding the intersection of these two agendas and the coverage of user needs by science and technology activities leads us to the development of the “market pull” indicators for emerging areas of research. (Author)

  9. The push and pull of new realities

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    Factors driving electricity industry restructuring in Canada are reviewed. It is conceded that much of the success of the industry will depend on its ability to supply electrical power according to customers' highly specific needs. Each provincial jurisdiction is facing a transition to greater competition, market segmentation and consumer protection. Climate change and other environmental challenges are also ongoing issues for the industry. However, the key driver for industry change is customer choice. Unbundling of services is the central issue which will respond to customer choice. As utilities are unbundling functions and services, they are also pursuing alliances with other industries. For example, the alliance of electricity and natural gas suppliers is resulting in consolidated energy service companies. A brief review of the current state of restructuring activities by the major electric utilities in Canada's ten provinces is also given

  10. Tunable Push-Pull Interactions in 5-Nitrosopyrimidines

    Czech Academy of Sciences Publication Activity Database

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

    2016-01-01

    Roč. 81, č. 9 (2016), s. 3780-3789 ISSN 0022-3263 R&D Projects: GA ČR GA15-11223S Institutional support: RVO:61388963 Keywords : polysubstituted 5-nitrosopyrimidines * molecular dynamics * NMR spectroscopy Subject RIV: CC - Organic Chemistry Impact factor: 4.849, year: 2016

  11. Kinematics of the field hockey penalty corner push-in.

    Science.gov (United States)

    Kerr, Rebecca; Ness, Kevin

    2006-01-01

    The aims of the study were to determine those variables that significantly affect push-in execution and thereby formulate coaching recommendations specific to the push-in. Two 50 Hz video cameras recorded transverse and longitudinal views of push-in trials performed by eight experienced and nine inexperienced male push-in performers. Video footage was digitized for data analysis of ball speed, stance width, drag distance, drag time, drag speed, centre of massy displacement and segment and stick displacements and velocities. Experienced push-in performers demonstrated a significantly greater (p push-in and a significantly faster ball speed than inexperienced performers. In addition, the experienced performers showed a significant positive correlation between ball speed and playing experience and tended to adopt a combination of simultaneous and sequential segment rotation to achieve accuracy and fast ball speed. The study yielded the following coaching recommendations for enhanced push-in performance: maximize drag distance by maximizing front foot-ball distance at the start of the push-in; use a combination of simultaneous and sequential segment rotations to optimise both accuracy and ball speed and maximize drag speed.

  12. 33 CFR 83.24 - Towing and pushing (Rule 24).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Towing and pushing (Rule 24). 83... NAVIGATION RULES RULES Lights and Shapes § 83.24 Towing and pushing (Rule 24). (a) A power-driven vessel when... it can best be seen. (b) Pushing vessel and pushed vessel rigidly connected in composite unit. When a...

  13. Workload balancing capability of pull systems in MTO production

    NARCIS (Netherlands)

    Germs, R.; Riezebos, J.

    2010-01-01

    Pull systems focusing on throughput time control and applicable in situations with high variety and customisation are scarce. This paper compares three unit-based pull systems that can cope with such situations: POLCA, CONWIP and m-CONWIP. These systems control the shop floor throughput time of

  14. Fuzzy Based PC-PUSH in CR-MANETs

    Directory of Open Access Journals (Sweden)

    S. Nejatian

    2014-01-01

    Full Text Available In cognitive radio (CR, the secondary user (SU needs to hand off its ongoing communication to an idle channel in order to avoid interference to the primary user (PU. Spectrum hand off issue becomes challenging in CR mobile ad hoc networks (CR-MANETs because of the uncertainty in spectrum availability, broad range of spectrum bands and lack of central entity. The purpose of this study is to design a unified spectrum handoff (USH scheme for CR-MANETs that considers the spectrum heterogeneity and its availability over time and space. A local flow hand off is performed when spectrum hand off cannot be carried out due to the SUs mobility. To improve further USH, preemptive unified spectrum handoff (PUSH algorithm is proposed in which two different preemptive hand off threshold regions are defined. The PUSH algorithm also predicts the cognitive link availability considering the PU interference boundary. Although the PUSH scheme improves the hand off performance, the number of spectrum hand offs due to the PU activity should be reduced in this scheme. Therefore, the PC-PUSH (Power Controller-PUSH scheme is proposed in which the fuzzy logic is used to improve the PUSH in terms of the number of spectrum handoffs because of the PU activity. The PC-PUSH decreases the interference to the PUs, while reducing the number of spectrum handoffs. The results show that the proposed scheme improves the link maintenance probability, decreases the hand off delay, and reduces the number of spectrum handoffs.

  15. Relationship between shoulder roll and hand propulsion in the front crawl stroke.

    Science.gov (United States)

    Kudo, Shigetada; Sakurai, Yoshihisa; Miwa, Takahiro; Matsuda, Yuji

    2017-05-01

    This study re-evaluated the magnitude of hand propulsion (HP) in the pull and push phases of the front crawl stroke and investigated the association between the angular velocity of shoulder roll (ω SR ) and hand propulsive lift (HP L ). ω SR was computed in the plane normal to a forward direction for 16 skilled swimmers performing the front crawl stroke at a maximal sprinting pace. HP, hand propulsive drag (HP D ) and HP L were determined by a dynamic pressure approach. HP and HP D in the pull phase were greater than in the push phase (P push phase. Eleven swimmers out of the 16 swimmers had a significant within-swimmers correlation between ω SR and HP L in the push phase (P push phase as the ω SR of rolling back to the neutral position became faster. A swimmer should use more drag for hand propulsion in the pull phase and propulsion from drag and lift equally in the push phase. Based on the relationship between ω SR and HP L in the push phase, a possible stroke technique to enhance HP L using ω SR is discussed.

  16. 49 CFR 218.99 - Shoving or pushing movements.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Shoving or pushing movements. 218.99 Section 218... Derails § 218.99 Shoving or pushing movements. (a)(1) Each railroad shall adopt and comply with an... violated the requirements of this section. (2) The following requirements for shoving or pushing movements...

  17. Clozapine

    Science.gov (United States)

    ... end of the plunger in the oral syringe. Push on the plunger so the medication goes back into the bottle and the air disappears. Pull ... syringe into the water in the cup. Pull back on the plunger and draw the water into the oral syringe. Push on the plunger to squirt the water into ...

  18. [Length of pushing efforts: pushing is not playing. Reply to the article of C. Le Ray and F. Audibert].

    Science.gov (United States)

    Schaal, J-P; Dreyfus, M; Bretelle, F; Carbonne, B; Dupuis, O; Foulhy, C; Goffinet, F; Houfflin-Debarge, V; Langer, B; Martin, A; Mercier, C; Mignon, A; Poulain, P; Simon, A; Teurnier, F; Verspyck, E; Riethmuller, D; Hoffmann, P; Pierre, F

    2008-11-01

    The aim of this work is to answer constructively to C. Le Ray and F. Audibert who were surprised that the French guidelines recommended an assisted delivery after 30 min pushing, even if the fetal heart rate is reassuring. We first resumed the definition of "second stage of labor", this word including the first phase with no pushing efforts and the second phase with active pushing of the mother. With that definition, the length of the second stage is around 60 min for the primipara and 20 min for the multipara, this length being modified by the use of peridural. We then specified the physiological mechanisms influencing the acidobasic equilibrium during the pushing time. Those mechanisms are difficult to consider because foetal heart rate monitoring is often "lost" during that phase. Altogether, these factors bring incertitude about progressive foetal acidosis and incapacity to diagnose it. Finally, the literature analysis teaches us that increasing the second stage of labor (inactive plus active phases) during the normal pregnancy seems to be at low risk for the foetus within the primiparas, but display a risk for the mother and so might be limited. Comparing the delayed pushing with the immediate pushing only lead us to conclude that delayed pushing is dangerous, as is prolonged second stage. In conclusion, we think that prolonging the second stage of labor is possible but must be by increasing the inactive first phase of the second stage, especially as long as we will not get a noninvasive and reliable method allowing assessing the well-being of the foetus.

  19. Experimental Investigations on the Pull-Out Behavior of Tire Strips Reinforced Sands.

    Science.gov (United States)

    Li, Li-Hua; Chen, Yan-Jun; Ferreira, Pedro Miguel Vaz; Liu, Yong; Xiao, Heng-Lin

    2017-06-27

    Waste tires have excellent mechanical performance and have been used as reinforcing material in geotechnical engineering; however, their interface properties are poorly understood. To further our knowledge, this paper examines the pull-out characteristics of waste tire strips in a compacted sand, together with uniaxial and biaxial geogrids also tested under the same conditions. The analysis of the results shows that the interlocking effect and pull-out resistance between the tire strip and the sand is very strong and significantly higher than that of the geogrids. In the early stages of the pull-out test, the resistance is mainly provided by the front portion of the embedded tire strips, as the pull-out test continues, more and more of the areas towards the end of the tire strips are mobilized, showing a progressive failure mechanism. The deformations are proportional to the frictional resistance between the tire-sand interface, and increase as the normal stresses increase. Tire strips of different wear intensities were tested and presented different pull-out resistances; however, the pull-out resistance mobilization patterns were generally similar. The pull-out resistance values obtained show that rubber reinforcement can provide much higher pull-out forces than the geogrid reinforcements tested here, showing that waste tires are an excellent alternative as a reinforcing system, regardless of the environmental advantages.

  20. Hybrid electric vehicles and electrochemical storage systems — a technology push-pull couple

    Science.gov (United States)

    Gutmann, Günter

    In the advance of fuel cell electric vehicles (EV), hybrid electric vehicles (HEV) can contribute to reduced emissions and energy consumption of personal cars as a short term solution. Trade-offs reveal better emission control for series hybrid vehicles, while parallel hybrid vehicles with different drive trains may significantly reduce fuel consumption as well. At present, costs and marketing considerations favor parallel hybrid vehicles making use of small, high power batteries. With ultra high power density cells in development, exceeding 1 kW/kg, high power batteries can be provided by adapting a technology closely related to consumer cell production. Energy consumption and emissions may benefit from regenerative braking and smoothing of the internal combustion engine (ICE) response as well, with limited additional battery weight. High power supercapacitors may assist the achievement of this goal. Problems to be solved in practice comprise battery management to assure equilibration of individual cell state-of-charge for long battery life without maintenance, and efficient strategies for low energy consumption.

  1. Modulating the electronic properties of asymmetric push–pull and symmetric Zn(II)-diarylporphyrinates with para substituted phenylethynyl moieties in 5,15 meso positions: A combined electrochemical and spectroscopic investigation

    International Nuclear Information System (INIS)

    Mussini, Patrizia Romana; Orbelli Biroli, Alessio; Tessore, Francesca; Pizzotti, Maddalena; Biaggi, Cinzia; Di Carlo, Gabriele; Lobello, Maria Grazia; De Angelis, Filippo

    2012-01-01

    Graphical abstract: - Abstract: Push–pull Zn(II)-porphyrinates have recently shown attracting performances as light harvesting systems in dye-sensitized solar cells (DSSCs). To fully exploit their intrinsically high efficiency it is important to finely tune their HOMO and LUMO levels, which can be achieved by proper choice of the push and pull substituents. Of course such target-oriented molecular design requires the availability of reliable relationships between molecular structure and electronic properties; therefore we have carried out a combined electrochemical, spectroscopic and computational investigation on a wide, systematic range of Zn(II)-porphyrinates 5,15 meso substituted with phenylethynyl linkers, including a first symmetric series carrying on the opposite terminals the same substituent (-N(CH 3 ) 2 , -OCH 3 , -COOCH 3 , -COOH, -NO 2 ); and a second push–pull one, with the terminal positions carrying one donor and one acceptor group belonging to the series above. Moreover, two suitably modified porphyrins allowed evaluation of the effects of (i) the presence or absence of the phenyl group in the linker between the porphyrin core and the acceptor group, and (ii) the effect of perfluorination on the same phenyl group. A rationalization scheme is proposed encompassing the whole porphyrin set, affording inter alia interesting clues on the different localization of the redox centres and effective conjugation between the porphyrin core and the side chains as a function of the molecular design.

  2. Effect of push frequency on the economy of wheelchair racers.

    Science.gov (United States)

    Goosey, V L; Campbell, I G; Fowler, N E

    2000-01-01

    The aim of the study was to examine the effect of varying push frequency on pushing economy (oxygen uptake at a given speed). Eight male wheelchair racers completed a series of exercise bouts on a wheelchair ergometer (Bromking Turbo Trainer, Bromakin, UK) at 6.58 m x s(-1). Initially, subjects self-selected their freely chosen push frequency (FCF); this was followed by 4 random trials pushing at 60, 80, 120, and 140% of this FCF. Steady state VO2 was determined using Douglas bags, and heart rate was recorded by telemetry. After each condition, a small capillary blood sample was obtained and analyzed for blood lactate concentration (BLa) and a rating of perceived exertion (RPE) was recorded. At 6.58 m x s(-1) oxygen uptake, RPE, and gross mechanical efficiency were nonlinearly related to push frequency. Analysis of variance showed a significant effect (P push frequency had little effect on HR although BLa increased linearly and was higher at the 140% FCF condition compared with 60% FCF (P push frequency increased. The start angle and end angle of hand contact were similar for conditions, whereas the range of trunk motion decreased with push frequency (P push frequency had an effect on pushing economy, and that the athletes' FCF was the most economical.

  3. New devices for measuring forces on the kayak foot bar and on the seat during flat-water kayak paddling: a technical report.

    Science.gov (United States)

    Nilsson, Johnny E; Rosdahl, Hans G

    2014-03-01

    The purpose was to develop and validate portable force-measurement devices for recording push and pull forces applied by each foot to the foot bar of a kayak and the horizontal force at the seat. A foot plate on a single-point force transducer mounted on the kayak foot bar underneath each foot allowed the push and pull forces to be recorded. Two metal frames interconnected with 4 linear ball bearings, and a force transducer allowed recording of horizontal seat force. The foot-bar-force device was calibrated by loading each foot plate with weights in the push-pull direction perpendicular to the foot plate surface, while the seat-force device was calibrated to horizontal forces with and without weights on the seat. A strong linearity (r2 = .99-1.0) was found between transducer output signal and load force in the push and pull directions for both foot-bar transducers perpendicular to the foot plate and the seat-force-measuring device. Reliability of both devices was tested by means of a test-retest design. The coefficient of variation (CV) for foot-bar push and pull forces ranged from 0.1% to 1.1%, and the CV for the seat forces varied from 0.6% to 2.2%. The current study opens up a field for new investigations of the forces generated in the kayak and ways to optimize kayak-paddling performance.

  4. Method to measure the force to pull and to break pin bones of fish.

    Science.gov (United States)

    Balaban, Murat O; Jie, Hubert; Yin Yee, Yin; Alçiçek, Zayde

    2015-02-01

    A texture measurement device was modified to measure the force required to pull pin bones from King salmon (Oncorhynchus tshawytscha), snapper (Pagrus auratus), and kahawai (Arripis trutta). Pulled bones were also subjected to tension to measure the breaking force. For all fish, the pulling force depended on the size of the fish, and on the length of the pin bone (P bones. For example, fresh small salmon (about 1500 g whole) required 600 g on average to pull pin bones, and large fish (about 3700 g whole) required 850 g. Longer bones required greater pulling force. The breaking force followed the same trend. In general, the breaking force was greater than the pulling force. This allows the removal of the bones without breaking them. There was no statistically significant (P > 0.05) difference between the forces (both pulling and breaking) from fresh and frozen/thawed samples, although in general frozen/thawed samples required less force to pull. With the quantification of pulling and breaking forces for pin bones, it is possible to design and build better, "more intelligent" pin bone removal equipment. © 2015 Institute of Food Technologists®

  5. Frobenius Pull Backs of Vector Bundles in Higher Dimensions

    Indian Academy of Sciences (India)

    We prove that for a smooth projective variety of arbitrary dimension and for a vector bundle over , the Harder–Narasimhan filtration of a Frobenius pull back of is a refinement of the Frobenius pull back of the Harder–Narasimhan filtration of , provided there is a lower bound on the characteristic (in terms of rank of ...

  6. Monte Carlo dosimetry of a tandem positioned beta-emitting intravascular brachytherapy source train

    International Nuclear Information System (INIS)

    Wallace, Steven A.; Schumer, Wendy; Horrigan, Mark

    2002-01-01

    Prevention of restenosis following interventional coronary procedures with catheter based beta-emitting sources is currently under clinical trial investigations. Systems utilizing fixed length source trains limit the clinician's ability to increase the radiation source length as required. A technique known as 'pull back' is used when the segment of artery requiring radiation is longer than the available fixed length source train. In this instance, tandem positioning of the fixed length source is used to treat the longer length of artery. The aim of this study was to examine the dosimetry of the junction region associated with pull back treatments using a commercially available 90 Sr/Y catheter based intravascular brachytherapy source train. Dose profiles were calculated, using the Monte Carlo code MCNP4B, at radial distances of 1.5, 2.0, and 2.5 mm for pull back techniques using 2.5 mm overlapping, abutting, and 2.5 mm spaced source trains. Results at the protocol prescription radius of 2 mm showed a junction dose elevated 61% above prescription for 2.5 mm overlapping source trains. For 2.5 mm spaced trains, this figure falls to 64% below prescription dose. In contrast, abutted source trains exhibited only a 1% depression below prescription dose in the junction region. The reference point dose rate per unit activity of this source was found to be consistent with previous studies

  7. Yarn Pull-Out as a Mechanism for Dissipation of Ballistic Impact Energy in Kevlar KM-2 Fabric, Part 1: Quasi-Static Characterization of Yarn Pull-Out

    National Research Council Canada - National Science Library

    Kirkwood, Keith

    2004-01-01

    .... This study reports the effects of fabric length, number of yarns pulled, arrangement of yarns, and transverse tension on the force-displacement curves for yarn pull-out tests on Kevlar KM-2 fabric...

  8. Optical pulling force and conveyor belt effect in resonator-waveguide system.

    Science.gov (United States)

    Intaraprasonk, Varat; Fan, Shanhui

    2013-09-01

    We present the theoretical condition and actual numerical design that achieves an optical pulling force in resonator-waveguide systems, where the direction of the force on the resonator is in the opposite direction to the input light in the waveguide. We also show that this pulling force can occur in conjunction with the lateral optical equilibrium effect, such that the resonator is maintained at the fixed distance from the waveguide while experiencing the pulling force.

  9. PUSH-ing Construction Communications & Going Viral for Safety

    OpenAIRE

    Prevost, Dan; McCall, Bill

    2018-01-01

    Over the past 2 years, the Indiana Toll Road Concession Co. (ITRCC) and its contractors have delivered the 80/90 PUSH project, an ambitious rehabilitation of 70 miles of the Indiana Toll Road. The team developed an aggressive communications program to keep its customers and community stakeholders informed, partnering with the Indiana Motor Truck Association to take its Put the Phone Down campaign to social media. Join us for a discussion.

  10. Effect of spontaneous pushing versus Valsalva pushing in the second stage of labour on mother and fetus: a systematic review of randomised trials.

    Science.gov (United States)

    Prins, M; Boxem, J; Lucas, C; Hutton, E

    2011-05-01

    To critically evaluate any benefit or harm for the mother and her baby of Valsalva pushing versus spontaneous pushing in the second stage of labour. Electronic databases from MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were systematically searched (last search May 2010). The reference lists of retrieved studies were searched by hand and an internet hand search of master theses and dissertations was performed. No date or language restriction was used. Randomised controlled trials that compared instructed pushing with spontaneous pushing in the second stage of labour were considered. Studies were evaluated independently for methodological quality and appropriateness for inclusion by two authors (MP and JB). The primary outcome was instrumental/operative delivery. Other outcomes were length of labour, any perineal repair, bladder function, maternal satisfaction. Infant outcomes included low Apgar score pushing technique (three studies; 425 women; mean difference 18.59 minutes; 95% CI 0.46-36.73 minutes). Neonatal outcomes did not differ significantly. Urodynamic factors measured 3 months postpartum were negatively affected by Valsalva pushing. Measures of first urge to void and bladder capacity were decreased (one study; 128 women; mean difference respectively 41.50 ml, 95% CI 8.40-74.60, and 54.60 ml, 95% CI 13.31-95.89). The evidence from our review does not support the routine use of Valsalva pushing in the second stage of labour. The Valsalva pushing method has a negative effect on urodynamic factors according to one study. The duration of the second stage of labour is shorter with Valsalva pushing but the clinical significance of this finding is uncertain. The primary studies are sparse, diverse and some flawed. Further research seems warranted. In the mean time supporting spontaneous pushing and encouraging women to choose their own method of pushing should be accepted as best clinical practice. © 2011 The Authors BJOG An

  11. Lithospheric-scale centrifuge models of pull-apart basins

    Science.gov (United States)

    Corti, Giacomo; Dooley, Tim P.

    2015-11-01

    We present here the results of the first lithospheric-scale centrifuge models of pull-apart basins. The experiments simulate relative displacement of two lithospheric blocks along two offset master faults, with the presence of a weak zone in the offset area localising deformation during strike-slip displacement. Reproducing the entire lithosphere-asthenosphere system provides boundary conditions that are more realistic than the horizontal detachment in traditional 1 g experiments and thus provide a better approximation of the dynamic evolution of natural pull-apart basins. Model results show that local extension in the pull-apart basins is accommodated through development of oblique-slip faulting at the basin margins and cross-basin faults obliquely cutting the rift depression. As observed in previous modelling studies, our centrifuge experiments suggest that the angle of offset between the master fault segments is one of the most important parameters controlling the architecture of pull-apart basins: the basins are lozenge shaped in the case of underlapping master faults, lazy-Z shaped in case of neutral offset and rhomboidal shaped for overlapping master faults. Model cross sections show significant along-strike variations in basin morphology, with transition from narrow V- and U-shaped grabens to a more symmetric, boxlike geometry passing from the basin terminations to the basin centre; a flip in the dominance of the sidewall faults from one end of the basin to the other is observed in all models. These geometries are also typical of 1 g models and characterise several pull-apart basins worldwide. Our models show that the complex faulting in the upper brittle layer corresponds at depth to strong thinning of the ductile layer in the weak zone; a rise of the base of the lithosphere occurs beneath the basin, and maximum lithospheric thinning roughly corresponds to the areas of maximum surface subsidence (i.e., the basin depocentre).

  12. [Development of Biliary Contrast Agents Remote Pushing Device].

    Science.gov (United States)

    Zhu, Haoyang; Dong, Dinghui; Luo, Yu; Ren, Fenggang; Zhang, Jing; Tan, Wenjun; Shi, Aihua; Hu, Liangshuo; Wu, Rongqian; Lyu, Yi

    2018-01-30

    A biliary contrast agents pushing device, including a syringe pushing system and a remote controller is introduced. The syringe pushing system comprises an injector card slot, a support platform and an injection bolus fader. A 20 mL syringe can be fitted on the syringe pushing system and kept with the ground about 30 degree. This system can perform air bubble pumping back and contrast agents bolus injection as well as speed adjustment. Remote controller is an infrared remote control which can start and stop the syringe pushing system. With this device, the remote controlled cholangiography technology can be achieved, which can not only protect doctors from X-ray radiation but also improve the traditional T-tube cholangiography and the contrast effect, reduce postoperative complications in patients as well. The application of this device will improve the current diagnosis and treatment system, the device will benefit the majority of doctors and patients.

  13. Pulling an intruder from a granular material: a novel depinning experiment

    Directory of Open Access Journals (Sweden)

    Zhang Yue

    2017-01-01

    Full Text Available Two-dimensional impact experiments by Clark et al. [2] identified the source of inertial drag to be caused by ‘collisions’ with a latent force network, leading to large fluctuations of the force experienced by the impactor. These collisions provided the major drag on an impacting intruder until the intruder was nearly at rest. As a complement, we consider controlled pull-out experiments where a buried intruder is pulled out of a material, starting from rest. This provides a means to better understand the non-inertial part of the drag force, and to explore the mechanisms associated with the force fluctuations. To some extent, the pull out process is a time reversed version of the impact process. In order to visualize this pulling process, we use 2D photoelastic disks from which circular intruders of different radii are pulled out. We present results about the dynamics of the intruder and the structures of the force chains inside the granular system as captured by slow and high speed imaging.

  14. Optimization of Contact Force and Pull-in Voltage for Series based MEMS Switch

    Directory of Open Access Journals (Sweden)

    Abhijeet KSHIRSAGAR

    2010-04-01

    Full Text Available Cantilever based metal-to-metal contact type MEMS series switch has many applications namely in RF MEMS, Power MEMS etc. A typical MEMS switch consists of a cantilever as actuating element to make the contact between the two metal terminals of the switch. The cantilever is pulled down by applying a pull-in voltage to the control electrode that is located below the middle portion of the cantilever while only the tip portion of the cantilever makes contact between the two terminals. Detailed analysis of bending of the cantilever for different pull-in voltages reveals some interesting facts. At low pull-in voltage the cantilever tip barely touches the two terminals, thus resulting in very less contact area. To increase contact area a very high pull-in voltage is applied, but it lifts the tip from the free end due to concave curving of the cantilever in the middle region of the cantilever where the electrode is located. Again it results in less contact area. Furthermore, the high pull-in voltage produces large stress at the base of the cantilever close to the anchor. Therefore, an optimum, pull-in voltage must exist at which the concave curving is eliminated and contact area is maximum. In this paper authors report the finding of optimum contact force and pull-in voltage.

  15. Oil pulling: A traditional method on the edge of evidence

    Directory of Open Access Journals (Sweden)

    H Mythri

    2017-01-01

    Full Text Available Introduction: Oil pulling is an ancient, traditional folk remedy that has been practiced for centuries in India and southern Asia as a holistic Ayurvedic technique. The practice of oil pulling involves placing a tablespoon of an edible oil (e.g. sesame, olive, sunflower, coconut inside the mouth, and swishing or “pulling” the oil through the teeth and oral cavity for anywhere from 1–5 minutes to up to 20 minutes or longer. Materials and Methods: Articles related to oil pulling were collected by using oil pulling as Keyword in Google and Medline. Out of the 21 related articles published till 2016, 6 articles with the proper study designs were used for analysis. Results: The studies were unreliable for many reasons, including the misinterpretation of results due to small sample size and improper study design. Conclusion: Though the promoters claim it as one of the best method to be as adjuvant to mechanical control methods, scientific evidences are lacking.

  16. Pull-production in repetitive remanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, D.W. Jr.

    1992-09-01

    In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele`s pull-production system and highlights design characteristics which are specific to remanufacturing applications.

  17. Pull-production in repetitive remanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, D.W. Jr.

    1992-09-01

    In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele's pull-production system and highlights design characteristics which are specific to remanufacturing applications.

  18. Station Program Note Pull Automation

    Science.gov (United States)

    Delgado, Ivan

    2016-01-01

    Upon commencement of my internship, I was in charge of maintaining the CoFR (Certificate of Flight Readiness) Tool. The tool acquires data from existing Excel workbooks on NASA's and Boeing's databases to create a new spreadsheet listing out all the potential safety concerns for upcoming flights and software transitions. Since the application was written in Visual Basic, I had to learn a new programming language and prepare to handle any malfunctions within the program. Shortly afterwards, I was given the assignment to automate the Station Program Note (SPN) Pull process. I developed an application, in Python, that generated a GUI (Graphical User Interface) that will be used by the International Space Station Safety & Mission Assurance team here at Johnson Space Center. The application will allow its users to download online files with the click of a button, import SPN's based on three different pulls, instantly manipulate and filter spreadsheets, and compare the three sources to determine which active SPN's (Station Program Notes) must be reviewed for any upcoming flights, missions, and/or software transitions. Initially, to perform the NASA SPN pull (one of three), I had created the program to allow the user to login to a secure webpage that stores data, input specific parameters, and retrieve the desired SPN's based on their inputs. However, to avoid any conflicts with sustainment, I altered it so that the user may login and download the NASA file independently. After the user has downloaded the file with the click of a button, I defined the program to check for any outdated or pre-existing files, for successful downloads, to acquire the spreadsheet, convert it from a text file to a comma separated file and finally into an Excel spreadsheet to be filtered and later scrutinized for specific SPN numbers. Once this file has been automatically manipulated to provide only the SPN numbers that are desired, they are stored in a global variable, shown on the GUI, and

  19. Affective and Sensory Correlates of Hair Pulling in Pediatric Trichotillomania

    Science.gov (United States)

    Meunier, Suzanne A.; Tolin, David F.; Franklin, Martin

    2009-01-01

    Hair pulling in pediatric populations has not received adequate empirical study. Investigations of the affective and sensory states contributing to the etiology and maintenance of hair pulling may help to elucidate the classification of trichotillomania (TTM) as an impulse control disorder or obsessive-compulsive spectrum disorder. The current…

  20. Prone positioning reduces severe pushing behavior: three case studies.

    Science.gov (United States)

    Fujino, Yuji; Amimoto, Kazu; Sugimoto, Satoshi; Fukata, Kazuhiro; Inoue, Masahide; Takahashi, Hidetoshi; Makita, Shigeru

    2016-09-01

    [Purpose] Pushing behavior is classically described as a disorder of body orientation in the coronal plane. Most interventions for pushing behavior have focused on correcting the deviation in vertical perception. However, pushing behavior seems to involve erroneous movements associated with excessive motor output by the non-paretic limbs and trunk. The present study aimed to inhibit muscular hyper-activity by placing the non-paretic limbs and trunk in the prone position. [Subjects and Methods] The subjects of the present study were 3 acute stroke patients with severe pushing behavior. The study consisted of the following 3 phases: baseline, intervention, and follow-up. In addition to conventional therapy, patients received relaxation therapy in the prone position for 10 minutes a day over 2 days. The severity of pushing behavior was assessed using the scale for contraversive pushing, and truncal balance was evaluated using the trunk control test. These assessments were performed before and after the baseline phase, and after the intervention and follow-up phases. [Results] At the baseline phase, both scores were poor. Both scores improved after the intervention and follow-up phases, and all the patients could sit independently. [Conclusion] Relaxation therapy in the prone position might ameliorate pushing behavior and impaired truncal balance.

  1. 49 CFR 392.63 - Towing or pushing loaded buses.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Towing or pushing loaded buses. 392.63 Section 392... COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.63 Towing or pushing loaded buses. No disabled bus with... passengers aboard for the purpose of towing or pushing any disabled motor vehicle, except in such...

  2. Perturbation training to promote safe independent mobility post-stroke: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Mansfield, Avril; Aqui, Anthony; Centen, Andrew; Danells, Cynthia J; DePaul, Vincent G; Knorr, Svetlana; Schinkel-Ivy, Alison; Brooks, Dina; Inness, Elizabeth L; McIlroy, William E; Mochizuki, George

    2015-06-06

    Falls are one of the most common medical complications post-stroke. Physical exercise, particularly exercise that challenges balance, reduces the risk of falls among healthy and frail older adults. However, exercise has not proven effective for preventing falls post-stroke. Falls ultimately occur when an individual fails to recover from a loss of balance. Thus, training to specifically improve reactive balance control could prevent falls. Perturbation training aims to improve reactive balance control by repeatedly exposing participants to postural perturbations. There is emerging evidence that perturbation training reduces fall rates among individuals with neurological conditions, such as Parkinson disease. The primary aim of this work is to determine if perturbation-based balance training can reduce occurrence of falls in daily life among individuals with chronic stroke. Secondary objectives are to determine the effect of perturbation training on balance confidence and activity restriction, and functional balance and mobility. Individuals with chronic stroke will be recruited. Participants will be randomly assigned to one of two groups: 1) perturbation training, or 2) 'traditional' balance training. Perturbation training will involve both manual perturbations (e.g., a push or pull from a physiotherapist), and rapid voluntary movements to cause a loss of balance. Training will occur twice per week for 6 weeks. Participants will record falls and activity for 12 months following completion of the training program. Standardized clinical tools will be used to assess functional balance and mobility, and balance confidence before and after training. Falls are a significant problem for those with stroke. Despite the large body of work demonstrating effective interventions, such as exercise, for preventing falls in other populations, there is little evidence for interventions that prevent falls post-stroke. The proposed study will investigate a novel and promising

  3. Report on ignitability testing of ''no-flow'' push bit

    International Nuclear Information System (INIS)

    Witwer, K.S.

    1997-01-01

    Testing was done to determine if an ignition occurs during a sixty foot drop of a Universal Sampler onto a push-mode bit in a flammable gas environment. Ten drops each of the sampler using both a push-mode and rotary mode insert onto a push-mode bit were completed. No ignition occurred during any of the drops

  4. The Effect of Knowledge Management Systems on Organizational Performance. Do Soldier and Unit Counterinsurgency Knowledge and Performance Improve Following ’Push’ or ’Adaptive-PushTraining

    Science.gov (United States)

    2009-01-01

    theory.................................................................................................24 Knowles’ theory of andragogy ...theories: Knowles’ andragogy theory and Gagné’s conditions of learning theory. Both may play a role in how a soldier learns during the push and...questions go beyond the scope of this research and will be left for future research. Knowles’ theory of andragogy Knowles’ theory of adult education

  5. The Uneven Legal Push for Europe

    DEFF Research Database (Denmark)

    Wind, Marlene; Martinsen, Dorte Sindbjerg; Rotger, Gabriel Pons

    2009-01-01

    National courts have been key players in the legal push for Europe, though notably to varying degrees. This paper examines the persisting variations in the referral rates of national courts and the underlying causal factors, aiming to better understand why some member states' courts have been more...... reluctant to join in the legal push for Europe. By using econometric methods, it challenges the modified neofunctionalist argument that the extent of intra-EC trade explains the referral practice of the individual member states. Majoritarian democracy is hypothesized as a causal factor in the low referral...... of majoritarian democracy on the number of referrals. The paper concludes that, owing to the uneven legal push for Europe, some member states and their citizens remain at arms' length from the legal integration process - and, in consequence, from the full impact of European integration....

  6. Progressive-overload whole-body vibration training as part of periodized, off-season strength training in trained women athletes.

    Science.gov (United States)

    Jones, Margaret T

    2014-09-01

    The purpose was to examine the effects of progressive-overload, whole-body vibration (WBV) training on strength and power as part of a 15-week periodized, strength training (ST) program. Eighteen collegiate women athletes with ≥1 year of ST and no prior WBV training participated in the crossover design. Random assignment to 1 of the 2 groups followed pretests of seated medicine ball throw (SMBT), single-leg hop for distance (LSLH, RSLH), countermovement jump (CMJ), 3 repetition maximum (3RM) front squat (FS), pull-up (PU), and 3RM bench press (BP). Whole-body vibration was two 3-week phases of dynamic and static hold body weight exercises administered 2 d·wk in ST sessions throughout the 15-week off-season program. Total WBV exposure was 6 minutes broken into 30-second bouts with 60-second rest (1:2 work-to-relief ratio). Exercises, frequency, and amplitude progressed in intensity from the first 3-week WBV training to the second 3-week phase. Repeated-measures analysis of variances were used to analyze the SMBT, CMJ, LSLH, RSLH, FS, PU, and BP tests. Alpha level was p ≤ 0.05. Front squat, LSLH, and RSLH increased (p = 0.001) from pre- to posttest; FS increased from mid- to posttest. Pull-up increased (p = 0.008) from pre- to posttest. Seated medicine ball throw and BP showed a trend of increased performance from pre- to posttest (p = 0.11). Two 3-week phases of periodized, progressive-overload WBV + ST training elicited gains in strength and power during a 15-week off-season program. Greatest improvements in performance tests occurred in the initial WBV phase. Implementing WBV in conjunction with ST appears to be more effective in the early phases of training.

  7. Research on Precision Tracking on Fast Steering Mirror and Control Strategy

    Science.gov (United States)

    Di, Lin; Yi-ming, Wu; Fan, Zhu

    2018-01-01

    Fast steering mirror is a device used for controlling the beam direction precisely. Due to the short travel of the push-pull FSM, a compound fast steering mirror system driven by both limited-angle voice coil motor and push-pull FSM together is proposed. In the compound FSM system, limited-angle voice coil motor quickly swings at wide angle, while the push-pull FSM do high frequency movement in a small range, which provides the system with the high bandwidth and long travel. In the control strategy, the method of combining feed-forward control in Kalman filtering with auto-disturbance rejection control is used to improve trajectory tracking accuracy. The simulation result shows that tracking accuracy measured by the compound method can be improved by more than 5 times than that of the conventional PID.

  8. Validity and Reliability of the PUSH Wearable Device to Measure Movement Velocity During the Back Squat Exercise.

    Science.gov (United States)

    Balsalobre-Fernández, Carlos; Kuzdub, Matt; Poveda-Ortiz, Pedro; Campo-Vecino, Juan Del

    2016-07-01

    Balsalobre-Fernández, C, Kuzdub, M, Poveda-Ortiz, P, and Campo-Vecino, Jd. Validity and reliability of the PUSH wearable device to measure movement velocity during the back squat exercise. J Strength Cond Res 30(7): 1968-1974, 2016-The purpose of this study was to analyze the validity and reliability of a wearable device to measure movement velocity during the back squat exercise. To do this, 10 recreationally active healthy men (age = 23.4 ± 5.2 years; back squat 1 repetition maximum [1RM] = 83 ± 8.2 kg) performed 3 repetitions of the back squat exercise with 5 different loads ranging from 25 to 85% 1RM on a Smith Machine. Movement velocity for each of the total 150 repetitions was simultaneously recorded using the T-Force linear transducer (LT) and the PUSH wearable band. Results showed a high correlation between the LT and the wearable device mean (r = 0.85; standard error of estimate [SEE] = 0.08 m·s) and peak velocity (r = 0.91, SEE = 0.1 m·s). Moreover, there was a very high agreement between these 2 devices for the measurement of mean (intraclass correlation coefficient [ICC] = 0.907) and peak velocity (ICC = 0.944), although a systematic bias between devices was observed (PUSH peak velocity being -0.07 ± 0.1 m·s lower, p ≤ 0.05). When measuring the 3 repetitions with each load, both devices displayed almost equal reliability (Test-retest reliability: LT [r = 0.98], PUSH [r = 0.956]; ICC: LT [ICC = 0.989], PUSH [ICC = 0.981]; coefficient of variation [CV]: LT [CV = 4.2%], PUSH [CV = 5.0%]). Finally, individual load-velocity relationships measured with both the LT (R = 0.96) and the PUSH wearable device (R = 0.94) showed similar, very high coefficients of determination. In conclusion, these results support the use of an affordable wearable device to track velocity during back squat training. Wearable devices, such as the one in this study, could have valuable practical applications for strength and conditioning coaches.

  9. Pulling cylindrical particles using a soft-nonparaxial tractor beam

    DEFF Research Database (Denmark)

    Novitsky, Andrey; Ding, Weiqiang; Wang, Maoyan

    2017-01-01

    In order to pull objects towards the light source a single tractor beam inevitably needs to be strongly nonparaxial. This stringent requirement makes such a tractor beam somewhat hypothetical. Here we reveal that the cylindrical shape of dielectric particles can effectively mitigate the nonparaxi......In order to pull objects towards the light source a single tractor beam inevitably needs to be strongly nonparaxial. This stringent requirement makes such a tractor beam somewhat hypothetical. Here we reveal that the cylindrical shape of dielectric particles can effectively mitigate...... the nonparaxiality requirements, reducing the incidence angle of the partial plane waves of the light beam down to 45 degrees and even to 30 degrees for respectively dipole and dipole-quadrupole objects. The optical pulling force attributed to the interaction of magnetic dipole and magnetic quadrupole moments...... and sorting of targeted particles....

  10. Does delayed pushing in the second stage of labor impact perinatal outcomes?

    Science.gov (United States)

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

    2012-11-01

    To estimate maternal, neonatal, and labor outcomes associated with delayed pushing. A retrospective cohort study of all consecutive women admitted to a single institution in labor at term who reached the second stage of labor. Pregnancies with multiple fetuses or major anomalies were excluded. Delayed pushing was defined as initiation of pushing ≥60 minutes after complete dilatation. Primary outcome was mode of delivery. Multivariable logistic regression was used to control for confounding. Of the 5290 women who met inclusion criteria, 471 (8.9%) employed delayed pushing, and 4819 (91.1%) pushed immediately. Delayed pushing was associated with increased rates of cesarean, operative vaginal delivery, maternal fever, and lower arterial cord pH. Duration of the second stage and length of time spent pushing were significantly longer with delayed pushing. Delayed pushing is associated with lower rates of spontaneous vaginal delivery and increased adverse maternal and neonatal outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. Contact Irritant Responses of Aedes aegypti Using Sublethal Concentration and Focal Application of Pyrethroid Chemicals

    OpenAIRE

    Manda, Hortance; Shah, Pankhil; Polsomboon, Suppaluck; Chareonviriyaphap, Theeraphap; Castro-Llanos, Fanny; Morrison, Amy; Burrus, Roxanne G.; Grieco, John P.; Achee, Nicole L.

    2013-01-01

    BACKGROUND: Previous studies have demonstrated contact irritant and spatial repellent behaviors in Aedes aegypti following exposure to sublethal concentrations of chemicals. These sublethal actions are currently being evaluated in the development of a push-pull strategy for Ae. aegypti control. This study reports on mosquito escape responses after exposure to candidate chemicals for a contact irritant focused push-pull strategy using varying concentrations and focal application. METHODS: Cont...

  12. Effect of vitrification on number of inner cell mass in mouse blastocysts in conventional straw, closed pulled straw, open pulled straw and cryoloop carriers

    International Nuclear Information System (INIS)

    Ghasem, S.; Negar, K.

    2013-01-01

    Objective: To compare the effect of using open and closed carriers on count of inner cell mass in vitrified mouse blastocyst after warming. Methods: The experimental study was conducted at Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, from April to September 2010. Forty female NMRI (Naval Medical Research Institute, USA) mice were injected with pregnant mares serum gonadotropin and human chorionic gonadotropin in order to induce super ovulation. Following the latter injection, two or three females were caged with the same-breed male mice. The presence of vaginal plug was examined the following morning. To collect blastocyst embryos, the pregnant females were sacrificed by cervical dislocation at 88-90 hours after the injection and dissected. Blastocysts were collected in phosphate-buffered saline and allocated to four groups: vitrification in conventional straw, closed pulled straw, open pulled straw and cryoloop. The vitrification solution was ethylene glycol, Ficol and sucrose (EFS) 20% and 40%. After storage for 1 month in liquid nitrogen, the blastocysts were thawed in 0.5 M sucrose then cultured in M16 medium. After 6 hours of culture, the number of expanded blastocysts was recorded and stained by double-dye technique. After staining, the number of total cell and inner cell mass was calculated. Results: The re-expansion rate of blastocysts in the cryoloop group (n=90; 78.26%) was significantly higher (p<0.05) than open pulled straw (n=83; 69.16%), closed pulled straw (n=68; 54.83%) and conventional straws (n=63; 51.21%) groups. Significant differences (p<0.05) in the number of inner cell mass in blastocysts vitrified in open pulled straws, closed straws and cryoloop with blastocysts cryopreserved in conventional straws. Conclusion: The re-expansion rate and total cell number of mouse blastocysts vitrified using open system had a better result compared with the closed system. The value of cryoloop and open pulled straws as carriers in

  13. Mechanism of oil-pulling therapy - in vitro study.

    Science.gov (United States)

    Asokan, Sharath; Rathinasamy, T K; Inbamani, N; Menon, Thangam; Kumar, S Senthil; Emmadi, Pamela; Raghuraman, R

    2011-01-01

    Oil pulling has been used extensively as a traditional Indian folk remedy without scientific proof for many years for strengthening teeth, gums and jaws and to prevent decay, oral malodor, bleeding gums and dryness of throat and cracked lips. The aim of this study was to evaluate the antibacterial activity of sesame oil and lignans isolated from sesame oil on oral microorganisms and to check whether saponification or emulsification occurs during oil-pulling therapy. The in vitro study was carried out in three different phases: (1) Antibacterial activity of the lignans and sesame oil were tested by minimum inhibitory concentration assay by agar dilution method and agar well diffusion method, respectively. (2) Increase in free fatty acid level of oil and the quantity of sodium hydroxide (NaOH) used up in the titration are good indicators of saponification process. This was assessed using analytical tests for vegetable oils. (3) Swished oil was observed under light microscope to assess the status of the oil, presence of microorganisms, oral debris and foreign bodies. Sesamin and sesamolin isolated from sesame oil did not have any antibacterial effect against oral microorganisms like Streptococcus mutans, Streptococcus mitis and Streptococcus viridans. Emulsification of sesame oil occurs during oil-pulling therapy. Increased consumption of NaOH in titration is a definite indication of a possible saponification process. The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

  14. Magnetic characterization of superparamagnetic nanoparticles pulled through model membranes.

    Science.gov (United States)

    Barnes, Allison L; Wassel, Ronald A; Mondalek, Fadee; Chen, Kejian; Dormer, Kenneth J; Kopke, Richard D

    2007-01-04

    To quantitatively compare in-vitro and in vivo membrane transport studies of targeted delivery, one needs characterization of the magnetically-induced mobility of superparamagnetic iron oxide nanoparticles (SPION). Flux densities, gradients, and nanoparticle properties were measured in order to quantify the magnetic force on the SPION in both an artificial cochlear round window membrane (RWM) model and the guinea pig RWM. Three-dimensional maps were created for flux density and magnetic gradient produced by a 24-well casing of 4.1 kilo-Gauss neodymium-iron-boron (NdFeB) disc magnets. The casing was used to pull SPION through a three-layer cell culture RWM model. Similar maps were created for a 4 inch (10.16 cm) cube 48 MGOe NdFeB magnet used to pull polymeric-nanoparticles through the RWM of anesthetized guinea pigs. Other parameters needed to compute magnetic force were nanoparticle and polymer properties, including average radius, density, magnetic susceptibility, and volume fraction of magnetite. A minimum force of 5.04 x 10(-16) N was determined to adequately pull nanoparticles through the in-vitro model. For the guinea pig RWM, the magnetic force on the polymeric nanoparticles was 9.69 x 10-20 N. Electron microscopy confirmed the movement of the particles through both RWM models. As prospective carriers of therapeutic substances, polymers containing superparamagnetic iron oxide nanoparticles were succesfully pulled through the live RWM. The force required to achieve in vivo transport was significantly lower than that required to pull nanoparticles through the in-vitro RWM model. Indeed very little force was required to accomplish measurable delivery of polymeric-SPION composite nanoparticles across the RWM, suggesting that therapeutic delivery to the inner ear by SPION is feasible.

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

    Science.gov (United States)

    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.

  16. Motion in the unstable thoracolumbar spine when spine boarding a prone patient

    Science.gov (United States)

    Conrad, Bryan P.; Marchese, Diana L.; Rechtine, Glenn R.; Horodyski, MaryBeth

    2012-01-01

    Introduction Previous research has found that the log roll (LR) technique produces significant motion in the spinal column while transferring a supine patient onto a spine board. The purpose of this project was to determine whether log rolling a patient with an unstable spine from prone to supine with a pulling motion provides better thoracolumbar immobilization compared to log rolling with a push technique. Methods A global instability was surgically created at the L1 level in five cadavers. Two spine-boarding protocols were tested (LR Push and LR Pull). Both techniques entailed performing a 180° LR rotation of the prone patient from the ground to the supine position on the spine board. An electromagnetic tracking device registered motion between the T12 and L2 vertebral segments. Six motion parameters were tracked. Repeated-measures statistical analysis was performed to evaluate angular and translational motion. Results Less motion was produced during the LR Push compared to the LR Pull for all six motion parameters. The difference was statistically significant for three of the six parameters (flexion–extension, axial translation, and anterior–posterior (A–P) translation). Conclusions Both the LR Push and LR Pull generated significant motion in the thoracolumbar spine during the prone to supine LR. The LR Push technique produced statistically less motion than the LR Pull, and should be considered when a prone patient with a suspected thoracolumbar injury needs to be transferred to a long spine board. More research is needed to identify techniques to further reduce the motion in the unstable spine during prone to supine LR. PMID:22330191

  17. Wheelchair pushing and turning: lumbar spine and shoulder loads and recommended limits.

    Science.gov (United States)

    Weston, Eric B; Khan, Safdar N; Marras, William S

    2017-12-01

    The objective of this study was to determine how simulated manual wheelchair pushing influences biomechanical loading to the lumbar spine and shoulders. Sixty-two subjects performed simulated wheelchair pushing and turning in a laboratory. An electromyography-assisted biomechanical model was used to estimate spinal loads. Moments at the shoulder joint, external hand forces and net turning torque were also assessed. Multiple linear regression techniques were employed to develop biomechanically based wheelchair pushing guidelines relating resultant hand force or net torque to spinal load. Male subjects experienced significantly greater spinal loading (p pushing (p pushing and turning can pose biomechanical risk to the lumbar spine and shoulders. Psychophysically determined maximum acceptable push forces do not appear to be protective enough of this biomechanical risk. Practitioner Summary: This laboratory study investigated biomechanical risk to the low back and shoulders during simulated wheelchair pushing. Manual wheelchair pushing posed biomechanical risk to the lumbar spine (in compression and A/P shear) and to the shoulders. Biomechanically determined wheelchair pushing thresholds are presented and are more protective than the closest psychophysically determined equivalents.

  18. Versatile H+ beam chopper system at LAMPF

    International Nuclear Information System (INIS)

    Lunsford, J.S.; Lawrence, G.P.; Bentley, R.F.

    1979-01-01

    The H + chopper system at LAMPF provides two modes (A and B) of beam chopping. Mode A provides single micropulses separated by 1 μs or more. Mode B provides a single pulse 50-ns to 10-μs long at the LAMPF repetition rate of 12 Hz. The mode of operation is selected with coaxial relays which can switch during the dead time between LAMPF macropulses. The chopper consists of 1-m-long push-pull helical-wound slow-wave deflecting structures having an axial pulse velocity of 0.04c, which matches the velocity of the proton beam. The helix ground-planes are biased by a pulser providing push-pull 500-V pulses to deflect the H + beam from the injection channel. In chopping mode A, the helical windings are driven by push-pull, 1000-V, 5-ns pulses delivered by a circuit utilizing avalanche transistors and planar triodes. In mode B, the helical windings are driven by push-pull, 1000-V, 50-ns to 10-μs long pulses, produced by a circuit utilizing beam-power tetrodes and fast SCRs. In both modes, these pulses cancel the ground-plane bias and permit beam pulses to be delivered to the linac

  19. Sistemas de control push-pull. Un estudio comparativo.

    OpenAIRE

    Ruiz Usano, Rafael; Muñoz Pérez, Miguel Ángel

    2001-01-01

    Un aspecto fundamental a nivel operacional en los sistemas de producción es la obtención de la cantidad deseada de unidades a producir con la mínima cantidad de inventario en proceso. Para conseguirlo podemos optar por distintos sistemas de control de l

  20. Compact two-beam push-pull free electron laser

    Science.gov (United States)

    Hutton, Andrew [Yorktown, VA

    2009-03-03

    An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

  1. Lithuanian "brain drain” causes : push and pull factors

    OpenAIRE

    Kazlauskienė, Aušra; Rinkevičius, Leonardas

    2006-01-01

    Differences of remuneration in regions are traditionally considered to be the reasons of migration. However, we should not give prominence solely to the reasons of economic migration. Even if the economic data of different states are similar, migration might be influenced by other factors that determine the movement of highly qualified workers, facing the brain drain problem. The paper aims to investigate the brain drain problems in Lithuania, reveal and evaluate their causes. It analyses the...

  2. Technology push is as important as marketing pull

    NARCIS (Netherlands)

    Nagel, A.P.

    1993-01-01

    This paper deals with the small and medium sized industrial firm that chooses to develop, produce and market new products on a regular basis. For such a firm it seems wise to give priority to ideas and products that have the ability to generate profit in the short run. Doing so, the firm focusses on

  3. Non-Model-Based Control of a Wheeled Vehicle Pulling Two Trailers to Provide Early Powered Mobility and Driving Experiences.

    Science.gov (United States)

    Sanders Td Vr, David A

    2018-01-01

    Non-model-based control of a wheeled vehicle pulling two trailers is proposed. It is a fun train for disabled children consisting of a locomotive and two carriages. The fun train has afforded opportunities for both disabled and able bodied young people to share an activity and has provided early driving experiences for disabled children; it has introduced them to assistive and powered mobility. The train is a nonlinear system and subject to nonholonomic kinematic constraints, so that position and state depend on the path taken to get there. The train is described, and then, a robust control algorithm using proportional-derivative filtered errors is proposed to control the locomotive. The controller was not dependent on an accurate model of the train, because the mass of the vehicle and two carriages changed depending on the number, size, and shape of children and wheelchair seats on the train. The controller was robust and stable in uncertainty. Results are presented to show the effectiveness of the approach, and the suggested control algorithm is shown to be acceptable without knowing the exact plant dynamics.

  4. Push-Back Leadership.

    Science.gov (United States)

    Tetenbaum, Toby J.; Tetenbaum, Hilary

    2003-01-01

    Describes push-back leadership, a model of leadership based on the work of Ronald Heifetz and Martin Linksky. Argues that the two key roles of the leader are to give the work back to people and to keep them within a healthy range of disequilibrium that generates creativity and innovation to solve organizational problems. (Author/LRW)

  5. Pulling a polymer with anisotropic stiffness near a sticky wall

    International Nuclear Information System (INIS)

    Tabbara, R; Owczarek, A L

    2012-01-01

    We solve exactly a two-dimensional partially directed walk model of a semi-flexible polymer that has one end tethered to a sticky wall, while a pulling force away from the adsorbing surface acts on the free end of the walk. This model generalizes a number of previously considered adsorption models by incorporating individual horizontal and vertical stiffness effects, in competition with a variable pulling angle. A solution to the corresponding generating function is found by means of the kernel method. While the phases and related phase transitions are similar in nature to those found previously the analysis of the model in terms of its physical variables highlights various novel structures in the shapes of the phase diagrams and related behaviour of the polymer. We review the results of previously considered sub-cases, augmenting these findings to include analysis with respect to the model’s physical variables—namely, temperature, pulling force, pulling angle away from the surface, stiffness strength and the ratio of vertical to horizontal stiffness potentials, with our subsequent analysis for the general model focusing on the effect that stiffness has on this pulling angle range. In analysing the model with stiffness we also pay special attention to the case where only vertical stiffness is included. The physical analysis of this case reveals behaviour more closely resembling that of an upward pulling force acting on a polymer than it does of a model where horizontal stiffness acts. The stiffness–temperature phase diagram exhibits re-entrance for low temperatures, previously only seen for three-dimensional or co-polymer models. For the most general model we delineate the shift in the physical behaviour as we change the ratio of vertical to horizontal stiffness between the horizontal-only and the vertical-only stiffness regimes. We find that a number of distinct physical characteristics will only be observed for a model where the vertical stiffness dominates

  6. Effects of pushing techniques in birth on mother and fetus: a randomized study.

    Science.gov (United States)

    Yildirim, Gulay; Beji, Nezihe Kizilkaya

    2008-03-01

    The Valsalva pushing technique is used routinely in the second stage of labor in many countries, and it is accepted as standard obstetric management in Turkey. The purpose of this study was to determine the effects of pushing techniques on mother and fetus in birth in this setting. This randomized study was conducted between July 2003 and June 2004 in Bakirkoy Maternity and Children's Teaching Hospital in Istanbul, Turkey. One hundred low-risk primiparas between 38 and 42 weeks' gestation, who expected a spontaneous vaginal delivery, were randomized to either a spontaneous pushing group or a Valsalva-type pushing group. Spontaneous pushing women were informed during the first stage of labor about spontaneous pushing technique (open glottis pushing while breathing out) and were supported in pushing spontaneously in the second stage of labor. Similarly, Valsalva pushing women were informed during the first stage of labor about the Valsalva pushing technique (closed glottis pushing while holding their breath) and were supported in using Valsalva pushing in the second stage of labor. Perineal tears, postpartum hemorrhage, and hemoglobin levels were evaluated in mothers; and umbilical artery pH, Po(2) (mmHg), and Pco(2) (mmHg) levels and Apgar scores at 1 and 5 minutes were evaluated in newborns in both groups. No significant differences were found between the two groups in their demographics, incidence of nonreassuring fetal surveillance patterns, or use of oxytocin. The second stage of labor and duration of the expulsion phase were significantly longer with Valsalva-type pushing. Differences in the incidence of episiotomy, perineal tears, or postpartum hemorrhage were not significant between the groups. The baby fared better with spontaneous pushing, with higher 1- and 5-minute Apgar scores, and higher umbilical cord pH and Po(2) levels. After the birth, women expressed greater satisfaction with spontaneous pushing. Educating women about the spontaneous pushing

  7. Hirschsprung's disease: problems with transition-zone pull-through.

    Science.gov (United States)

    Ghose, S I; Squire, B R; Stringer, M D; Batcup, G; Crabbe, D C

    2000-12-01

    It is generally accepted that if surgery for Hirschsprung's disease is to be successful, ganglionic bowel must be anastomosed to the lower rectum or anal canal. Above the aganglionic distal bowel lies a transition zone (TZ) where more subtle abnormalities of innervation are apparent. The significance of this transition zone in respect to the functional outcome of surgery has received little attention. The aim of this study was to identify the incidence of transition zone pull-through (TZPT) in a cohort of children who underwent surgery for Hirschsprung's disease, to identify the reasons why TZPTs occurred, and to identify the functional consequences. The authors report the long-term outcome of these children with emphasis on bowel function and the results of subsequent surgery. A Retrospective study was conducted of children treated at a single institution from 1979 through 1994. TZPT patients were subject to detailed review of surgical records and histopathologic material. Thirteen children were identified with a TZPT. In 12 cases, histopathologic errors contributed to the TZPT: in 5 cases this was caused by single point biopsies missing an asymmetrical TZ, whereas in 7 cases the histopathologic features of the TZ were not recognized. In 1 case the TZPT was caused by surgical error. As a consequence of the TZPT 7 children underwent repeat pull-through. One child is fully continent, one has daytime fecal continence, and 2 others are incontinent. Two children have permanent stomas. One child is clean with antegrade colonic washouts. Repeat pull-throughs were not attempted in 6 children. Two children have achieved full continence, 2 have permanent stomas, 1 is clean with antegrade colonic washouts, and 1 child receives regular suppositories. Transition zone pull-throughs occurred because of a combination of surgical and histopathologic errors. The transition zone may follow an asymmetric course around the circumference of the bowel and may be missed if single

  8. The string-pulling paradigm in comparative psychology.

    Science.gov (United States)

    Jacobs, Ivo F; Osvath, Mathias

    2015-05-01

    String pulling is one of the most widely used paradigms in comparative psychology. First documented 2 millennia ago, it has been a well-established scientific paradigm for a century. More than 160 bird and mammal species have been tested in over 200 studies with countless methodological variations. The paradigm can be used to address a wide variety of issues on animal cognition; for example, what animals understand about contact and connection as well as whether they rely on perceptual feedback, grasp the functionality of strings, generalize across conditions, apply their knowledge flexibly, and possess insight. Mammals are typically tested on a horizontal configuration, birds on a vertical one, making the studies difficult to compare; in particular, pulling a string vertically requires better coordination and attention. A species' performance on the paradigm is often influenced by its ecology, especially concerning whether limbs are used for foraging. Many other factors can be of importance and should be considered. The string-pulling paradigm is easy to administer, vary, and apply to investigate a wide array of cognitive abilities. Although it can be and has been used to compare species, divergent methods and unclear reporting have limited its comparative utility. With increasing research standards, the paradigm is expected to become an even more fundamental tool in comparative psychology. (c) 2015 APA, all rights reserved).

  9. An investigation into the cognition behind spontaneous string pulling in New Caledonian crows.

    Directory of Open Access Journals (Sweden)

    Alex H Taylor

    Full Text Available The ability of some bird species to pull up meat hung on a string is a famous example of spontaneous animal problem solving. The "insight" hypothesis claims that this complex behaviour is based on cognitive abilities such as mental scenario building and imagination. An operant conditioning account, in contrast, would claim that this spontaneity is due to each action in string pulling being reinforced by the meat moving closer and remaining closer to the bird on the perch. We presented experienced and naïve New Caledonian crows with a novel, visually restricted string-pulling problem that reduced the quality of visual feedback during string pulling. Experienced crows solved this problem with reduced efficiency and increased errors compared to their performance in standard string pulling. Naïve crows either failed or solved the problem by trial and error learning. However, when visual feedback was available via a mirror mounted next to the apparatus, two naïve crows were able to perform at the same level as the experienced group. Our results raise the possibility that spontaneous string pulling in New Caledonian crows may not be based on insight but on operant conditioning mediated by a perceptual-motor feedback cycle.

  10. The geometry of pull-apart basins in the southern part of Sumatran strike-slip fault zone

    Science.gov (United States)

    Aribowo, Sonny

    2018-02-01

    Models of pull-apart basin geometry have been described by many previous studies in a variety tectonic setting. 2D geometry of Ranau Lake represents a pull-apart basin in the Sumatran Fault Zone. However, there are unclear geomorphic traces of two sub-parallel overlapping strike-slip faults in the boundary of the lake. Nonetheless, clear geomorphic traces that parallel to Kumering Segment of the Sumatran Fault are considered as inactive faults in the southern side of the lake. I demonstrate the angular characteristics of the Ranau Lake and Suoh complex pull-apart basins and compare with pull-apart basin examples from published studies. I use digital elevation model (DEM) image to sketch the shape of the depression of Ranau Lake and Suoh Valley and measure 2D geometry of pull-apart basins. This study shows that Ranau Lake is not a pull-apart basin, and the pull-apart basin is actually located in the eastern side of the lake. Since there is a clear connection between pull-apart basin and volcanic activity in Sumatra, I also predict that the unclear trace of the pull-apart basin near Ranau Lake may be covered by Ranau Caldera and Seminung volcanic products.

  11. Design and development of a surface micro-machined push–pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

    International Nuclear Information System (INIS)

    Dey, Sukomal; Koul, Shiban K

    2012-01-01

    A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push–pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push–pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push–pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB −1 FOM over 0–40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°–360° over 0–40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0–40 GHz band. (paper)

  12. The great carbon push-pull: where science is pushing and policy is pulling the official forest carbon inventory of the US

    Science.gov (United States)

    C.W. Woodall; G.M. Domke; J. Coulston; M.B. Russell; J.A. Smith; C.H. Perry; S. Healey; A. Gray

    2015-01-01

    A national system of field inventory plots (FIA) is the primary data source for the annual assessment of US forest carbon (C) stocks and stock-change to meet reporting requirements under the United Nations Framework Convention on Climate Change (UNFCCC). The inventory data and their role in national carbon reporting continue to evolve. The framework of the previous C...

  13. Trustworthy content push

    OpenAIRE

    Kuntze, Nicolai; Schmidt, Andreas U.

    2006-01-01

    Delivery of content to mobile devices gains increasing importance in industrial environments to support employees in the field. An important application are e-mail push services like the fashionable Blackberry. These systems are facing security challenges regarding data transport to, and storage of the data on the end user equipment. The emerging Trusted Computing technology offers new answers to these open questions.

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

    Science.gov (United States)

    Zelik, Karl E; Adamczyk, Peter G

    2016-12-01

    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. © 2016. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

    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.

  16. Exercise-Based Performance Enhancement and Injury Prevention for Firefighters: Contrasting the Fitness- and Movement-Related Adaptations to Two Training Methodologies.

    Science.gov (United States)

    Frost, David M; Beach, Tyson A C; Callaghan, Jack P; McGill, Stuart M

    2015-09-01

    Using exercise to enhance physical fitness may have little impact on performers' movement patterns beyond the gym environment. This study examined the fitness and movement adaptations exhibited by firefighters in response to 2 training methodologies. Fifty-two firefighters were assigned to a movement-guided fitness (MOV), conventional fitness (FIT), or control (CON) group. Before and after 12 weeks of training, participants performed a fitness evaluation and laboratory-based test. Three-dimensional lumbar spine and frontal plane knee kinematics were quantified. Five whole-body tasks not included in the interventions were used to evaluate the transfer of training. FIT and MOV groups exhibited significant improvements in all aspects of fitness; however, only MOV exhibited improvements in spine and frontal plane knee motion control when performing each transfer task (effect sizes [ESs] of 0.2-1.5). FIT exhibited less controlled spine and frontal plane knee motions while squatting, lunging, pushing, and pulling (ES: 0.2-0.7). More MOV participants (43%) exhibited only positive posttraining changes (i.e., improved control), in comparison with FIT (30%) and CON (23%). Fewer negative posttraining changes were also noted (19, 25, and 36% for MOV, FIT, and CON). These findings suggest that placing an emphasis on how participants move while exercising may be an effective training strategy to elicit behavioral changes beyond the gym environment. For occupational athletes such as firefighters, soldiers, and police officers, this implies that exercise programs designed with a movement-oriented approach to periodization could have a direct impact on their safety and effectiveness by engraining desirable movement patterns that transfer to occupational tasks.

  17. RATE-DEPENDENT PULL-OUT BEARING CAPACITY OF PILES BY SIMILITUDE MODEL TESTS USING SEEPAGE FORCE

    Science.gov (United States)

    Kato, Tatsuya; Kokusho, Takaji

    Pull-out test of model piles was conducted by varying the pull-out velocity and skin friction of piles using a seepage force similitude model test apparatus. Due to the seepage consolidation under the pressure of 150kPa, the effective stress distribution in a prototype saturated soil of 17m could be successfully reproduced in the model ground of 28cm thick, in which the pull-out tests were carried out. The pull-out load rose to a peak value at small displacement, and then decreased to a residual value. At the same time, pore pressure in the vicinity of the pile decreased due to suction near the tip and the positive dilatancy near the pile skin. The maximum pull-out load, pile axial load, side friction and the corresponding displacement increased dramatically with increasing pull-out velocity. It was found that these rate-dependent trends become more prominent with increasing skin friction.

  18. Chemo-mechanical pushing of proteins along single-stranded DNA.

    Science.gov (United States)

    Sokoloski, Joshua E; Kozlov, Alexander G; Galletto, Roberto; Lohman, Timothy M

    2016-05-31

    Single-stranded (ss)DNA binding (SSB) proteins bind with high affinity to ssDNA generated during DNA replication, recombination, and repair; however, these SSBs must eventually be displaced from or reorganized along the ssDNA. One potential mechanism for reorganization is for an ssDNA translocase (ATP-dependent motor) to push the SSB along ssDNA. Here we use single molecule total internal reflection fluorescence microscopy to detect such pushing events. When Cy5-labeled Escherichia coli (Ec) SSB is bound to surface-immobilized 3'-Cy3-labeled ssDNA, a fluctuating FRET signal is observed, consistent with random diffusion of SSB along the ssDNA. Addition of Saccharomyces cerevisiae Pif1, a 5' to 3' ssDNA translocase, results in the appearance of isolated, irregularly spaced saw-tooth FRET spikes only in the presence of ATP. These FRET spikes result from translocase-induced directional (5' to 3') pushing of the SSB toward the 3' ssDNA end, followed by displacement of the SSB from the DNA end. Similar ATP-dependent pushing events, but in the opposite (3' to 5') direction, are observed with EcRep and EcUvrD (both 3' to 5' ssDNA translocases). Simulations indicate that these events reflect active pushing by the translocase. The ability of translocases to chemo-mechanically push heterologous SSB proteins along ssDNA provides a potential mechanism for reorganization and clearance of tightly bound SSBs from ssDNA.

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

    Science.gov (United States)

    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

  20. Conditions for sustainability of Academic Collaborative Centres for Public Health in the Netherlands: a mixed methods design.

    Science.gov (United States)

    Jansen, Maria W J; van Oers, Hans A M; Middelweerd, Mizzi D R; van de Goor, Ien A M; Ruwaard, Dirk

    2015-08-21

    Contemporary research should increasingly be carried out in the context of application. Nowotny called this new form of knowledge production Mode-2. In line with Mode-2 knowledge production, the Dutch government in 2006 initiated the so-called Academic Collaborative Centres (ACC) for Public Health. The aim of these ACCs is to build a regional, sustainable knowledge-sharing network to deliver socially robust knowledge. The present study aims to highlight the enabling and constraining push and pull factors of these ACCs in order to assess whether the ACCs are able to build and strengthen a sustainable integrated organizational network between public health policy, practice, and research. Our empirical analysis builds on a mixed methods design. Quantitative data was derived from records of a survey sent to all 11 ACCs about personnel investments, number and nature of projects, and earning power. Qualitative data was derived from 21 in-depth interviews with stakeholders involved. The interviews were tape-recorded, transcribed, and manually coded as favourable or unfavourable pull or push factors. The extra funding appeared to be the most enabling push factor. The networks secured external grants for about 150 short- and long-term Mode-2 knowledge production projects in the past years. Enabling pull factors improved, especially the number of policy-driven short-term research projects. Exchange agents were able to constructively deal with the constraining push factors, like university's publication pressure and budget limitations. However, the constraining pull factors like local government's involvement and their low demand for scientific evidence were difficult to overcome. A clear improvement of the organizational networks was noticed whereby the ACC's were pushed rather than pulled. Efforts are needed to increase the demand for scientific and socially robust evidence from policymakers and to resolve the regime differences between the research and policy systems, in

  1. Addressing Younger Workers’ Needs: The Promoting U through Safety and Health (PUSH Trial Outcomes

    Directory of Open Access Journals (Sweden)

    Diane S. Rohlman

    2016-08-01

    Full Text Available Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health. All younger workers (14–24 years old hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen’s d 0.4. However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior.

  2. Addressing Younger Workers’ Needs: The Promoting U through Safety and Health (PUSH) Trial Outcomes

    Science.gov (United States)

    Rohlman, Diane S.; Parish, Megan; Elliot, Diane L.; Hanson, Ginger; Perrin, Nancy

    2016-01-01

    Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health). All younger workers (14–24 years old) hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years) completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen’s d) 0.4). However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior. PMID:27517968

  3. Fecal incontinence after single-stage Soave's pull-through ...

    African Journals Online (AJOL)

    Journal Home > Vol 8, No 1 (2012) > ... Demographic, clinical data, preoperative investigations, operative records, postoperative ... Keywords: fecal continence, Hirschsprung's disease, Soave's operation, transanal endorectal pull-through ...

  4. Pull-out strength of a headed stud in cracked concrete

    International Nuclear Information System (INIS)

    Takiguchi, K.; Hotta, H.

    1995-01-01

    Pull-out strength of a headed stud due to cone failure of concrete with/without cracks were examined. This paper presents empirical data basis to decide the criteria for designing a headed stud embedded in a shear wall under earthquake. As a result, it is known that cracks running through the stud reduce the pull-out strength, but it almost recovers when the cracks are closed again by an external compressive load. (author). 2 refs., 10 figs., 1 tab

  5. Future application of Czochralski crystal pulling for silicon

    Science.gov (United States)

    Matlcok, J. H.

    1985-08-01

    Czochralski (Cz) crystal pulling has been the predominant method used for preparing silicon single crystal for the past twenty years. The fundamental technology used has changed little. However, great strides have been made in learning how to make the crystals bigger and of better quality at ever increasing productivity rates. Currently charge sizes of 50 kg of polycrystal silicon are being used for production and crystals up to ten inches in diameter have been grown without major difficulty. The largest material actually being processed in silicon wafer form is 150 mm (6 inches) in diameter. Growing of crystals in a magnetic field has proved to be particularly useful for microscopic impurity control. Major developments in past years on equipment for Cz crystal pulling have included the automatic growth control of the diameter as well as the starting core of the crystal, the use of magnetic fields and around the crystal puller to supress convection, various recharging schemes for dopant control and the use of continuous liquid feed in the crystal puller. The latter, while far from being a reliable production process, is ideal in concept for major improvement in Cz crystal pulling. The Czochralski process will maintain its dominance of silicon crystal production for many years.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. On-bead chemical synthesis and display of phosphopeptides for affinity pull-down proteomics

    DEFF Research Database (Denmark)

    Malene, Brandt; Madsen, Jens C.; Bunkenborg, Jakob

    2006-01-01

    We describe a new method for phosphopeptide proteomics based on the solid-phase synthesis of phosphopeptides on beads suitable for affinity pull-down experiments. Peptide sequences containing the Bad Ser112 and Ser136 phosphorylation motifs were used as bait in affinity pull-down experiments...... (aldehyde) at the C terminus for potential activity-based proteomics. The synthetic support-bound Bad phosphopeptides were able to pull down 14-3-3zeta. Furthermore, Bad phosphopeptides bound endogenous 14-3-3 proteins, and all seven members of the 14-3-3 family were identified by mass spectrometry....... In control experiments, none of the unphosphorylated Bad peptides bound transfected 14-3-3zeta or endogenous 14-3-3. We conclude that the combined synthesis and display of phosphopeptides on-bead is a fast and efficient method for affinity pull-down proteomics....

  10. Dynamics of general and specially trained of women-weightlifters at the stage of specialized basic training

    Directory of Open Access Journals (Sweden)

    Viktor Slobodyanuk

    2015-04-01

    Full Text Available Purpose: to determine the dynamics of the general and special training of women-weightlifters different groups weight categories for annual macrocycle at the stage of specialized basic training. Materials and Methods: indexes long jump, running 30 meters, push-ups, jumps on how Abalakova index and wrist strength athletes different schools of Ukraine. Results: found dynamic indicators of general and special training of women-weightlifters different groups weight categories at the stage of basic training six specialized schools in Ukraine. Conclusions: the results of the study provide an opportunity to consider certain indicators in planning differentiated training programs to improve the training process athletes for women-weightlifters at the stage of specialized basic training different groups weight categories in the annual macrocycle.

  11. The tectonic stress field evolution of India since the Oligocene

    Digital Repository Service at National Institute of Oceanography (India)

    Müller, R.D.; Yatheesh, V.; Shuhail, M.

    reconstructed plate geometries following Seton et al. (2012). We reconstruct the plate boundary configuration and age-area distribution of ocean crust around Australia through time to obtain estimates for ridge push, slab pull and collisional forces acting... on the Indo-Australian Plate since the early Cretaceous, following the methodology outlined in Dyksterhuis et al. (2005a; 2005b). In the case of the Indo-Australian Plate the dominant plate driving forces are the ridge push, slab pull and collisional forces...

  12. Effects of pushing techniques during the second stage of labor: A randomized controlled trial.

    Science.gov (United States)

    Koyucu, Refika Genç; Demirci, Nurdan

    2017-10-01

    Spontaneous pushing is a method that is used in the management of the second stage of labor and suggested to be more physiological for the mother and infant. The present study aims to evaluate the effects of pushing techniques on the mother and newborn. This randomized prospective study was performed between June 2013-March 2014 in a tertiary maternity clinic in Istanbul. 80 low risk, nulliparous cases were randomized to pushing groups. Valsalva pushing group was told to hold their breath while pushing. No visual-verbal instructions were given to spontaneous pushing group and they were encouraged to push without preventing respiration. Demographic data, second stage period, perineal laceration rates, fetal heart rate patterns, presence of meconium stained amniotic liquid, newborn APGAR scores, POP-Q examination and Q-tip test results were evaluated in these cases. The second stage of labor was significantly longer with spontaneous pushing. Decrease in Hb levels in valsalva pushing group was determined to be higher than spontaneous pushing group. An increased urethral mobility was observed in valsalva pushing group. Although the duration of the second stage of labor was longer compared to valsalva pushing technique, women were able to give birth without requiring any verbal or visual instruction, without exceeding the limit value of two hours and without affecting fetal wellness and neonatal results. Copyright © 2017. Published by Elsevier B.V.

  13. Effect of spontaneous pushing versus Valsalva pushing in the second stage of labour on mother and fetus: a systematic review of randomised trials

    NARCIS (Netherlands)

    Prins, M. [=Marianne; Boxem, J.; Lucas, C.; Hutton, E.

    2011-01-01

    To critically evaluate any benefit or harm for the mother and her baby of Valsalva pushing versus spontaneous pushing in the second stage of labour. Electronic databases from MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were systematically searched (last search May

  14. Variations of the ionization push frequency in the ASK-1 chamber

    International Nuclear Information System (INIS)

    Krivoshapkin, P.A.; Mamrukova, V.P.; Skripin, G.V.; Shafer, G.V.

    1997-01-01

    The data on frequency push in the ASK-1 chamber at the Yakutsk station for 1954-1994 are analyzed. The observed eleven-year and half-year push variations are related to the solar activity. The narrowly directed galactic anisotropy with 6-8 h direction, coinciding with the direction of the helio-magnetosphere tail, formed by the solar system motion relative to stars is identified in a daily motion by sidereal time. The great barometric and temperature coefficients of the frequency pushes are obtained. This indicates the prevailing role of the nuclear-active particles in formation of pushes

  15. [Methods of pushing at vaginal delivery and pelvi-perineal consequences. Review].

    Science.gov (United States)

    Ratier, N; Balenbois, E; Letouzey, V; Marès, P; de Tayrac, R

    2015-03-01

    The main objective of that review was to evaluate the pelvi-perineal consequences of the different methods of pushing at vaginal delivery. A review on PubMed, the Cochrane Library and EM-Premium was performed from 1984 to 2014. Among 29 manuscripts analysed, only nine randomised controlled trials (including one meta-analysis of three trials) comparing Valsalva and spontaneous pushing were selected. A 10 th study, secondary analysis of a randomized controlled trial comparing different methods of perineal protection (warm compresses, massage and manual protection), was also selected. Two trials have shown that spontaneous pushing reduces the risk of perineal tears, but studies were heterogeneous and discordant results do not allowed definitive conclusions. Results on the duration of the second stage of labour are conflicting. The method of pushing does not seem to affect the rate of episiotomy, instrumental delivery and cesarean section. Maternal satisfaction seems to be better after spontaneous pushing. It seems that there is no negative effect of spontaneous pushing on neonate well-being, and one study has shown a significant improvement of prenatal fetal parameters during the expulsive phase. According to current knowledge, both techniques of pushing during the expulsive phase at delivery seem comparable in terms of duration, risk of perineal tears and neonatal outcome. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. FAKTOR PENDORONG DAN PENARIK WISATAWAN BACKPACKER MANCANEGARA BERWISATA KE BALI

    Directory of Open Access Journals (Sweden)

    Gayatri Manik

    2017-01-01

    Full Text Available Trend backpackers is growing in various areas, including in Bali. Backpackers have been identified as having “a preference for budget accommodation, independently organized travel and emphasis on meeting other travellers, longer rather than brief holidays. The purpose of this research are to anlyses the push and pull factors that motivate the foreign backpacker tourists traveled to Bali. Sample on this research is 200 respondents of backpackers and using purposive sampling technique. Offline questionnaires are used for data collecting and the analysis technique is based on factor analysis. The results of research shows that the push factors backpackers traveled to Bali are (1 facilitation of social interaction, (2 self-identity, (3 relaxation, (4 prestige, (5 adventure (6 novelty. The push factor that dominantly is facilitation of social interaction. The pull factors are (1 cultural/historical, (2 affordable price, (3 variety seeking, (4 tourism facilities, (5 safety and clean, (6 environment. The pull factor that dominantly is Cultural / Historical.

  17. Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect

    Science.gov (United States)

    Zhu, Xingfu; Ingraham, Thomas; Søvik, Eirik

    2016-01-01

    Social insects make elaborate use of simple mechanisms to achieve seemingly complex behavior and may thus provide a unique resource to discover the basic cognitive elements required for culture, i.e., group-specific behaviors that spread from “innovators” to others in the group via social learning. We first explored whether bumblebees can learn a nonnatural object manipulation task by using string pulling to access a reward that was presented out of reach. Only a small minority “innovated” and solved the task spontaneously, but most bees were able to learn to pull a string when trained in a stepwise manner. In addition, naïve bees learnt the task by observing a trained demonstrator from a distance. Learning the behavior relied on a combination of simple associative mechanisms and trial-and-error learning and did not require “insight”: naïve bees failed a “coiled-string experiment,” in which they did not receive instant visual feedback of the target moving closer when tugging on the string. In cultural diffusion experiments, the skill spread rapidly from a single knowledgeable individual to the majority of a colony’s foragers. We observed that there were several sequential sets (“generations”) of learners, so that previously naïve observers could first acquire the technique by interacting with skilled individuals and, subsequently, themselves become demonstrators for the next “generation” of learners, so that the longevity of the skill in the population could outlast the lives of informed foragers. This suggests that, so long as animals have a basic toolkit of associative and motor learning processes, the key ingredients for the cultural spread of unusual skills are already in place and do not require sophisticated cognition. PMID:27701411

  18. Upper Extremity Muscle Activity During In-Phase and Anti-Phase Continuous Pushing Tasks.

    Science.gov (United States)

    Gruevski, Kristina M; Hodder, Joanne N; Keir, Peter J

    2017-11-01

    To determine the effect of anti-phase, in-phase bimanual and unimanual simulated industrial pushing tasks and frequency on upper extremity muscle activity. Research investigating symmetrical (in-phase) and asymmetrical (anti-phase) pushing exertions is limited despite a high prevalence in industry. Fifteen female participants completed five pushing tasks using a dual handle apparatus at three frequencies: 15 cycles per minute (cpm), 30 cpm, and self-selected. Tasks included two bimanual symmetrical pushes (constrained and unconstrained), two bimanual asymmetrical pushes (reciprocating and continuous), and one right unimanual push. Surface electromyography (EMG) from the right anterior, middle, and posterior deltoid (AD, MD, and PD); right and left trapezius (RT and LT); right pectoralis major (PM); and right and left external obliques (REO and LEO) was collected and normalized to maximum voluntary effort. There was a task by frequency interaction in the AD, MD, PD, and RT ( p pushes and constrained, in-phase pushes had the highest muscle activity demands and the least amount of variability in muscle activity and therefore may present the greatest risk of injury. Anti-phase pushing is known to have a greater cognitive demand, and this study demonstrated that it also has a greater physical demand when performed continuously.

  19. Medical and Non-Medical Factors Influencing Utilization of Delayed Pushing in the Second Stage

    Science.gov (United States)

    FREY, Heather A.; TUULI, Methodius G.; CORTEZ, Sarah; ODIBO, Anthony O.; ROEHL, Kimberly A.; SHANKS, Anthony L.; MACONES, George A.; CAHILL, Alison G.

    2014-01-01

    Objective To evaluate factors impacting selection to delayed pushing in the second stage of labor. Study design 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 modelling was used to identify factors independently associated with delayed pushing. Results We identified 471 women who delayed pushing and 4,819 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. Conclusion We identified multiple factors associated with use of delayed pushing. This study helps to define current patterns of second stage labor management. PMID:23208765

  20. Push-off reactions in recovery after tripping discriminate young subjects, older non-fallers and older fallers.

    Science.gov (United States)

    Pijnappels, Mirjam; Bobbert, Maarten F; van Dieën, Jaap H

    2005-06-01

    Tripping is a major cause for falls, especially in the elderly. This study investigated whether falls in the elderly can be attributed to inadequate push-off reactions by the support limb in the recovery after a trip. Twelve young (20-34 years) and eleven older (65-72 years) men and women walked over a platform and were tripped several times over an obstacle that suddenly appeared from the floor. Kinematics and ground reactions forces of the support limb during push-off were measured of falls and successful recoveries. Young subjects did not fall. The older subjects were divided into a group of four non-fallers and seven fallers. Older fallers showed insufficient reduction of the angular momentum during push-off and less proper placement of the recovery limb. This was due to a lower rate of change of moment generation in all support limb joints and a lower peak ankle moment. Onset of knee moment generation was slightly delayed in older fallers. Improvement over trials was ascribed to better positioning of the recovery limb, as no clear differences were seen in the joint moments of the support limb. In conclusion, the contribution of the support limb to prevent a fall after tripping is decreased in older adults. Lower limb strength could be an underlying factor and strength training might help to reduce fall risk.

  1. Single borehole test sensitivity towards crack and rock parameter. Lesson Hortberg; Einbohrlochtracertestsensitivitaet gegenueber Riss und Gesteinsparametern. Lektion Horstberg

    Energy Technology Data Exchange (ETDEWEB)

    Ghergut, Iulia; Behrens, Horst; Sauter, Martin [Goettingen Univ. (Germany). Angewandte Geologie

    2012-10-16

    The novel experiments of the GeoZentrum Hanover (Hanover, Federal Republic of Germany) on geothermal energy at the well bore Horstberg in the south heath also motivated the accompanying tracertest-mindset to move away from the tracer job stereotypes. For some possible designs at the tracertest at this drilling (forced-gradient divergent push by water fracking of Detfurth perforation, single-screen push-pull at Solling perforation, single-screen push-pull at Detfurth perforation, and so forth) the analysis shows how and why the controlling parameter do not comply with the mental basic pattern of the expectations at the tracertests ('tracertest by crack {yields} characterization of the crack', 'tracer residence time {yields} prognosis of the thermal lifetime').

  2. Arterial cord blood lactate at birth correlates with duration of pushing efforts.

    Science.gov (United States)

    Dessolle, Lionel; Lebrec, Jeremie; Daraï, Emile

    2010-01-01

    To evaluate the impact of the duration of pushing efforts on arterial cord blood lactate values. This was a prospective observational study of 124 consecutive normal vaginal deliveries in a tertiary teaching hospital. Arterial cord blood lactate was determined immediately at birth with a test strip method. Univariate and multivariate analyses were performed to check for clinical determinants of lactate levels. The main measure was lactate according to the duration of pushing efforts. Arterial cord lactates increased significantly and were strongly correlated with the duration of pushing efforts, independent of gestational age and birthweight. Women pushing for more than 20 min had higher arterial cord blood lactates (4.9 +/- 1.4 vs. 3.3 +/- 1.16 mM, respectively) and a higher rate of lactates >6 mM (18 vs. 3%) than those pushing for less than 20 min. At normal delivery, arterial cord blood lactates increase significantly with the duration of pushing efforts. Pushing for more than 20 min is associated with an increased risk of metabolic acidosis in the neonate. Further studies are required to evaluate the clinical significance of these observations. 2009 S. Karger AG, Basel.

  3. Postoperative Course and Complications after Pull-through Vaginoplasty for Distal Vaginal Atresia.

    Science.gov (United States)

    Mansouri, Roshanak; Dietrich, Jennifer E

    2015-12-01

    To report the usual postoperative course and complications after pull-through vaginoplasty for isolated distal vaginal atresia. Retrospective chart review at Texas Children's Hospital of all patients who were diagnosed with isolated distal vaginal atresia and underwent pull-through vaginoplasty during the study time frame. None. Postoperative complications such as vaginal stenosis or infection and postoperative vaginal diameter. Sixteen patients were identified and charts were reviewed. Patients were initially evaluated by pelvic magnetic resonance imaging and found to have distended hematometrocolpos with distal vaginal atresia. All patients underwent pull-through vaginoplasty with similar operative techniques. The average distance from the perineum to the level of the obstruction was 1.84 ± 1.2 cm. Two patients, both with obstructions at greater than 3 cm, experienced stricture formation postoperatively. Four patients (25%) experienced postoperative vaginitis. One patient (6.25%) experienced a postoperative urinary tract infection. Two groups (3 cm or less versus greater than 3 cm) were compared, and the presence of stricture was statistically different based on mean centimeters from perineum prior to pull-through vaginoplasty (P = .038). Distal vaginal atresia is managed with pull-through vaginoplasty. Atresias that extend greater than 3 cm from the perineum are at increased risk for vaginal stricture formation and should be followed to monitor for their formation. Other complications are infrequent and minor. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  4. Restoration of Hyperspectral Push-Broom Scanner Data

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg; Conradsen, Knut

    1997-01-01

    Several effects combine to distort the multispectral data that are obtained from push-broom scanners. We develop an algorithm for restoration of such data, illustrated on images from the ROSIS scanner. In push-broom scanners variation between elements in the detector array results in a strong...... back into the original spectral space results in noise corrected variables. The noise components will now have been removed from the entire original data set by working on a smaller set of noise contaminated transformed variables only. The application of the above techniques results in a dramatic...

  5. New laparoscopic peritoneal pull-through vaginoplasty technique

    Directory of Open Access Journals (Sweden)

    Pravin Mhatre

    2014-01-01

    Full Text Available Background: Many reconstructive surgical procedures have been described for vaginal agenesis. Almost all of them are surgically challenging, multi-staged, time consuming or leave permanent scars on abdomen or skin retrieval sites. Aim: A new simple technique using laparoscopic peritoneal pull-through in creation of neo vagina has been described. Material and Methods: Total of thirty six patients with congenital absence of vagina (MRKH syndrome were treated with laparoscopic peritoneal pull through technique of Dr. Mhatre between 2003 till 2012. The author has described 3 different techniques of peritoneal vaginoplasty. Results: This technique has given excellent results over a period of one to seven years of follow-up. The peritoneal lining changes to stratified squamous epithelium resembling normal vagina and having acidic Ph. Conclusion: Apart from giving excellent normal vaginal function, as the ovary became accessible per vaginum three patients underwent ovum retrieval and pregnancy using surrogate mother, thus making this a fertility enhancing procedure.

  6. Methodical basis of training of cadets for the military applied heptathlon competitions

    Directory of Open Access Journals (Sweden)

    R.V. Anatskyi

    2017-12-01

    Full Text Available The purpose of the research is to develop methodical bases of training of cadets for the military applied heptathlon competitions. Material and methods: Cadets of 2-3 courses at the age of 19-20 years (n=20 participated in researches. Cadets were selected by the best results of exercises performing included into the program of military applied heptathlon competitions (100 m run, 50 m freestyle swimming, Kalashnikov rifle shooting, pull-up, obstacle course, grenade throwing, 3000 m run. Preparation took place on the basis of training center. All trainings were organized and carried out according to the methodical basics: in a week preparation microcycle five days cadets had two trainings a day (on Saturday was one training, on Sunday they had rest. The selected exercises with individual loads were performed, Results : Sport scores demonstrated top results in the performance of 100 m run, 3000 m run and pull-up. The indices of performing exercise "obstacle course" were much lower than expected. Rather low results were demonstrated in swimming and shooting. Conclusions . Results of researches indicate the necessity of quality improvement: cadets’ weapons proficiency; physical readiness to perform the exercises requiring complex demonstration of all physical qualities.

  7. Control of trunk motion following sudden stop perturbations during cart pushing.

    Science.gov (United States)

    Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

    2011-01-04

    External perturbations during pushing tasks have been suggested to be a risk factor for low-back symptoms. An experiment was designed to investigate whether self-induced and externally induced sudden stops while pushing a high inertia cart influence trunk motions, and how flexor and extensor muscles counteract these perturbations. Twelve healthy male participants pushed a 200 kg cart at shoulder height and hip height. Pushing while walking was compared to situations in which participants had to stop the cart suddenly (self-induced stop) or in which the wheels of the cart were unexpectedly blocked (externally induced stop). For the perturbed conditions, the peak values and the maximum changes from the reference condition (pushing while walking) of the external moment at L5/S1, trunk inclination and electromyographic amplitudes of trunk muscles were determined. In the self-induced stop, a voluntary trunk extension occurred. Initial responses in both stops consisted of flexor and extensor muscle cocontraction. In self-induced stops this was followed by sustained extensor activity. In the externally induced stops, an external extension moment caused a decrease in trunk inclination. The opposite directions of the internal moment and trunk motion in the externally induced stop while pushing at shoulder height may indicate insufficient active control of trunk posture. Consequently, sudden blocking of the wheels in pushing at shoulder height may put the low back at risk of mechanical injury. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Ultrasonic Evaluation of the Pull-Off Adhesion between Added Repair Layer and a Concrete Substrate

    Science.gov (United States)

    Czarnecki, Slawomir

    2017-10-01

    This paper concerns the evaluation of the pull-off adhesion between a concrete added repair layer with variable thickness and a concrete substrate, based on parameters assessed using ultrasonic pulse velocity (UPV) method. In construction practice, the experimental determination of pull-off adhesion f b, between added repair layer and a concrete substrate is necessary to assess the quality of repair. This is usually carried out with the use of pull-off method which results in local damage of the added concrete layer in all the testing areas. Bearing this in mind, it is important to describe the method without these disadvantages. The prediction of the pull-off adhesion of the two-layer concrete elements with variable thickness of each layer might be provided by means of UPV method with two-sided access to the investigated element. For this purpose, two-layered cylindrical specimens were obtained by drilling the borehole from a large size specially prepared concrete element. Those two-layer elements were made out of concrete substrate layer and Polymer Cement Concrete (PCC) mortar as an added repair layer. The values of pull-off adhesion f b of the elements were determined before obtaining the samples by using the semi-destructive pull-off method. The ultrasonic wave velocity was determined in samples with variable thickness of each layer and was then compared to theoretical ultrasonic wave velocity predicted for those specimens. The regression curve for the dependence of velocity and pull-off adhesion, determined by the pulloff method, was made. It has been proved that together with an increase of ratio of investigated ultrasonic wave velocity divided by theoretical ultrasonic wave velocity, the pull-off adhesion value f b between added repair layer with variable thickness and a substrate layer also increases.

  9. An Extra Push from Entrance-Channel Effects

    International Nuclear Information System (INIS)

    Grar, Nabila; Rowley, Neil

    2006-01-01

    The fusion probability for heavy symmetric systems is known to show certain very specific features. Apart from the large variance of the fusion barrier distribution, it is found that the energy at which the s-wave transmission is 0.5 is shifted to an energy significantly higher than the nominal (e.g. Bass) Coulomb barrier. This last feature is referred to in the literature as the 'extra push' effect. Many models have been devised to explain the origin of these findings. It is worth noting, however, that despite the extra push, the capture cross section is still greatly enhanced at the very lowest energies. This fact cannot be explained within the framework of macroscopic theories involving conditional saddle points or frictional forces. We have performed full coupled-channel calculations for heavy, symmetric systems treating correctly the long-range Coulomb excitations of the collective quadrupole- and octupole-phonon states in the target and projectile. The results obtained show that the extra push and the overall shape of the fusion probability are simply explained by these entrance-channel effects

  10. Body pushing, prescription drugs and hospital admission.

    Science.gov (United States)

    Byard, Roger W; Kenneally, Michaela

    2017-09-01

    A 39-year-old man died of multi-organ failure complicating mixed drug toxicity that included methadone, oxazepam, oxycodone and nitrazepam. His past medical history involved alcohol and poly-substance abuse with chronic self-harm and suicidal ideation. There had been multiple hospital admissions for drug overdoses. At autopsy the most unusual finding was of two packages of 10 tablets each, wrapped in thin plastic film within the rectum. The insertion of drugs into body orifices and cavities has been termed body pushing to distinguish it from body packing where illicit drugs are wrapped and swallowed for transport and smuggling, and body stuffing where small amounts of loosely wrapped or unwrapped drugs are swallowed to conceal evidence from police. This case demonstrates that body pushing may not always involve illicit drugs or attempted concealment from police or customs officials. It appears that the drugs had been hidden to ensure an additional supply during the time of residence in hospital. The extent to which body pushing is currently being used by patients to smuggle drugs into secure medical facilities is yet to be determined.

  11. Pushing nanoparticles of La0.7Sr0.3MnO3

    International Nuclear Information System (INIS)

    Ma, Y.-R.; Liou Yung; Yao, Y.-D.

    2004-01-01

    Pushing nanoparticles of La 0.7 Sr 0.3 MnO 3 (LSMO) on a native SiO 2 surface using atomic force microscopy (AFM) in the tapping mode is presented. The pushing is accompanied by a repulsive tip-sample interaction between the AFM tip and the LSMO nanoparticles and the physisorption of the LSMO on the SiO 2 surface. The AFM images show scratch artifacts on the surface, indicating that artificial scratches are strongly related to the pushing of the LSMO nanoparticles. A possible approach to pushing nanoparticles is proposed

  12. Relationship between linear velocity and tangential push force while turning to change the direction of the manual wheelchair.

    Science.gov (United States)

    Hwang, Seonhong; Lin, Yen-Sheng; Hogaboom, Nathan S; Wang, Lin-Hwa; Koontz, Alicia M

    2017-08-28

    Wheelchair propulsion is a major cause of upper limb pain and injuries for manual wheelchair users with spinal cord injuries (SCIs). Few studies have investigated wheelchair turning biomechanics on natural ground surfaces. The purpose of this study was to investigate the relationship between tangential push force and linear velocity of the wheelchair during the turning portions of propulsion. Using an instrumented handrim, velocity and push force data were recorded for 25 subjects while they propel their own wheelchairs on a concrete floor along a figure-eight-shaped course at a maximum velocity. The braking force (1.03 N) of the inside wheel while turning was the largest of all other push forces (p<0.05). Larger changes in squared velocity while turning were significantly correlated with higher propulsive and braking forces used at the pre-turning, turning, and post-turning phases (p<0.05). Subjects with less change of velocity while turning needed less braking force to maneuver themselves successfully and safely around the turns. Considering the magnitude and direction of tangential force applied to the wheel, it seems that there are higher risks of injury and instability for upper limb joints when braking the inside wheel to turn. The results provide insight into wheelchair setup and mobility skills training for wheelchair users.

  13. Relationship between isometric and dynamic strength in recreationally trained men.

    Science.gov (United States)

    McGuigan, Michael R; Newton, Michael J; Winchester, Jason B; Nelson, Arnold G

    2010-09-01

    The purpose of this investigation was to examine the relationships between measures of maximal isometric force (peak force [PF]), rate of force development (RFD), vertical jump performance (VJ) and 1-repetition maximum (1RM) strength in recreationally trained men. The subjects in this study were 26 men ([mean +/- SD]: age 22 +/- 1 years; height 175 +/- 7 cm; mass 90 +/- 10 kg). They were tested for PF using the isometric midthigh pull exercise. The 1RM for the squat and bench press exercise were determined as a measure of dynamic strength. Explosive strength was measured as RFD from the isometric force-time curve. Correlations between the variables were calculated using Pearson product moment correlation coefficient. There was a nearly perfect correlation between measures of PF and 1RM squat (r = 0.97, p isometric maximum strength determined during the isometric midthigh pull test correlated well with 1RM and VJ testing. However, RFD measured during the same test did not appear to correlate as well with other measures. The isometric midthigh pull provides an efficient method for assessing strength in recreationally trained individuals. Practitioners wishing to obtain performance data related to maximum strength may wish to consider isometric testing as a less time intensive method of testing.

  14. 33 CFR 164.76 - Towline and terminal gear for towing alongside and pushing ahead.

    Science.gov (United States)

    2010-07-01

    ... towing alongside and pushing ahead. 164.76 Section 164.76 Navigation and Navigable Waters COAST GUARD... Towline and terminal gear for towing alongside and pushing ahead. The owner, master, or operator of each vessel towing alongside or pushing ahead shall ensure that the face wires, spring lines, and push gear...

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

    Science.gov (United States)

    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 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.

  16. An evaluation of the fluoroscopy-guided percutaneous gastrostomy with the pull technique

    International Nuclear Information System (INIS)

    Uhm, Chang Wook; Won, Jong Yun; Yu, Jeong Sik; Ko, Heung Kyu; Lee, Kwang Hun; Lee, Do Yun; Lee, Jong Tae

    2008-01-01

    To evaluate the safety and usefulness of the fluoroscopy-guided percutaneous gastrostomy (FPG) using a large profile gastrostomy tube accompanied with the pull technique, and without the use of an endoscopy or a gastropexy. From March 2005 to February 2007, 25 patients underwent an FPG using a large profile gastrostomy tube accompanied by the pull technique, in which a 24F pull-type tube was inserted into a patient's mouth and was pulled to the upper abdominal puncture site using a snare, under fluoroscopy. The 18 patients with difficulty swallowing due to muscular atrophic lateral sclerosis or transitional myodystrophy included 5 cases of quadriplegia, 1 case of Parkinson's disease, and 1 metastatic mediastinal tumor. The technical success rate, occurrence of complications, and clinical outcomes were examined. The technical success rate was found to be 100%. In addition, the retention periods for the indwelling tube ranged from 1 to 24 months (mean: 6.5 months), with all tubes retained at a normal position with normal function. No procedure-related mortality occurred. One patient (4%) did however develop a complication in the form of ascites and ascitic fluid leakage around the tube, which was of hepatic origin and was ultimately resolved after the drainage of ascites. As a result of this study the FPG, accompanied with the pull technique using a 24F tube, should be considered as a safe and effective method for examining patients. It was found to have a high success rate and a low complication rate

  17. An evaluation of the fluoroscopy-guided percutaneous gastrostomy with the pull technique

    Energy Technology Data Exchange (ETDEWEB)

    Uhm, Chang Wook; Won, Jong Yun; Yu, Jeong Sik; Ko, Heung Kyu; Lee, Kwang Hun; Lee, Do Yun; Lee, Jong Tae [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2008-04-15

    To evaluate the safety and usefulness of the fluoroscopy-guided percutaneous gastrostomy (FPG) using a large profile gastrostomy tube accompanied with the pull technique, and without the use of an endoscopy or a gastropexy. From March 2005 to February 2007, 25 patients underwent an FPG using a large profile gastrostomy tube accompanied by the pull technique, in which a 24F pull-type tube was inserted into a patient's mouth and was pulled to the upper abdominal puncture site using a snare, under fluoroscopy. The 18 patients with difficulty swallowing due to muscular atrophic lateral sclerosis or transitional myodystrophy included 5 cases of quadriplegia, 1 case of Parkinson's disease, and 1 metastatic mediastinal tumor. The technical success rate, occurrence of complications, and clinical outcomes were examined. The technical success rate was found to be 100%. In addition, the retention periods for the indwelling tube ranged from 1 to 24 months (mean: 6.5 months), with all tubes retained at a normal position with normal function. No procedure-related mortality occurred. One patient (4%) did however develop a complication in the form of ascites and ascitic fluid leakage around the tube, which was of hepatic origin and was ultimately resolved after the drainage of ascites. As a result of this study the FPG, accompanied with the pull technique using a 24F tube, should be considered as a safe and effective method for examining patients. It was found to have a high success rate and a low complication rate.

  18. What Are They Talking About? Analyzing Code Reviews in Pull-Based Development Model

    Institute of Scientific and Technical Information of China (English)

    Zhi-Xing Li; Yue Yu; Gang Yin; Tao Wang; Huai-Min Wang

    2017-01-01

    Code reviews in pull-based model are open to community users on GitHub. Various participants are taking part in the review discussions and the review topics are not only about the improvement of code contributions but also about project evolution and social interaction. A comprehensive understanding of the review topics in pull-based model would be useful to better organize the code review process and optimize review tasks such as reviewer recommendation and pull-request prioritization. In this paper, we first conduct a qualitative study on three popular open-source software projects hosted on GitHub and construct a fine-grained two-level taxonomy covering four level-1 categories (code correctness, pull-request decision-making, project management, and social interaction) and 11 level-2 subcategories (e.g., defect detecting, reviewer assigning, contribution encouraging). Second, we conduct preliminary quantitative analysis on a large set of review comments that were labeled by TSHC (a two-stage hybrid classification algorithm), which is able to automatically classify review comments by combining rule-based and machine-learning techniques. Through the quantitative study, we explore the typical review patterns. We find that the three projects present similar comments distribution on each subcategory. Pull-requests submitted by inexperienced contributors tend to contain potential issues even though they have passed the tests. Furthermore, external contributors are more likely to break project conventions in their early contributions.

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

    Science.gov (United States)

    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 (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.

  20. Mechanism of oil-pulling therapy -In vitro study

    Directory of Open Access Journals (Sweden)

    Sharath Asokan

    2011-01-01

    Conclusion: The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

  1. Pushing Boundaries while Maintaining Stability

    DEFF Research Database (Denmark)

    Lippke, Lena; Wegener, Charlotte

    at the same time. The exploration of transforming practices shows how disturbances in relation to the ‘normal’ practices are created and thus makes invisible conventions which are taken for granted visible. Thus, this paper addresses two types of invisibility: the unnoticed boundary-pushing practices...

  2. Developing technology pushed breakthroughs: an empirical study

    Directory of Open Access Journals (Sweden)

    Jari Sarja

    2017-12-01

    Full Text Available Developing a technology push product that brings real novelty to the market is difficult, risky and costly. This case study analyzes success factors defined by the literature. True industrial cases, representing Finnish ICT firms in their early phase after a successful market entry, were researched for the success factor analysis. The whole set of the previously introduced success factors were variably supported, and three new factors arose. Because the technology pushed development processes are risky with high failure rates, the validated success factors are valuable knowledge for the developments intensive firm’s management.

  3. The influence of the tire inflation on pull properties of agriculture tractors

    Directory of Open Access Journals (Sweden)

    Jakub Katrenčík

    2013-01-01

    Full Text Available Agricultural tractors are robust and versatile machines, which must comply with the basic requirements of users under various conditions. The main requirements include economical and reliable operation and high performance. Fuel economy could be improved using multiple methods, for example a well trained operator, adequate farming conditions and optimal tire inflation. Tractor tires transmit engine power to the surface and as such they are crucial to tractor operation. In the first part of the field measurement, all tires were inflated to 180kPa, while in the second part of the field measurements the tire pressure was set to 75kPa in front tires and to 65 kPa in rear tires. The results of the field measurement of the John Deere 6920S tractor with different tire inflation shows that pull performance increased by 9.9% and wheel slip decreased by 9.7%.

  4. Minimizing pulling geometry errors in atomic force microscope single molecule force spectroscopy.

    Science.gov (United States)

    Rivera, Monica; Lee, Whasil; Ke, Changhong; Marszalek, Piotr E; Cole, Daniel G; Clark, Robert L

    2008-10-01

    In atomic force microscopy-based single molecule force spectroscopy (AFM-SMFS), it is assumed that the pulling angle is negligible and that the force applied to the molecule is equivalent to the force measured by the instrument. Recent studies, however, have indicated that the pulling geometry errors can drastically alter the measured force-extension relationship of molecules. Here we describe a software-based alignment method that repositions the cantilever such that it is located directly above the molecule's substrate attachment site. By aligning the applied force with the measurement axis, the molecule is no longer undergoing combined loading, and the full force can be measured by the cantilever. Simulations and experimental results verify the ability of the alignment program to minimize pulling geometry errors in AFM-SMFS studies.

  5. Fluoroscopy-Guided Removal of Pull-Type Gastrostomy Tubes

    International Nuclear Information System (INIS)

    Ahlers, Christopher M.; Schneider, Jens; Lachmann, Ricarda; Herber, Sascha; Dueber, Christoph; Pitton, Michael B.

    2008-01-01

    These case reports demonstrate a radiologic interventional technique for removal of pull-type gastrostomy tubes. This approach proved to be a safe and efficient procedure in two patients. The procedure may be applicable in situations where endoscopic attempts fail.

  6. A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modula......This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase...

  7. Effect of honeybee stinger and its microstructured barbs on insertion and pull force.

    Science.gov (United States)

    Ling, Jintian; Song, Zhenhua; Wang, Jiarui; Chen, Keyun; Li, Jiyu; Xu, Shujia; Ren, Lei; Chen, Zhipeng; Jin, Dianwen; Jiang, Lelun

    2017-04-01

    Worker honeybee is well-known for its stinger with microscopic backward-facing barbs for self-defense. The natural geometry of the stinger enables painless penetration and adhesion in the human skin to deliver poison. In this study, Apis cerana worker honeybee stinger and acupuncture microneedle (as a barbless stinger) were characterized by Scanning Electron Microscope (SEM). The insertion and pull process of honeybee stinger into rabbit skin was performed by a self-developed mechanical loading equipment in comparison with acupuncture needle. In order to better understand the insertion and pull mechanisms of the stinger and its barbs in human multilayer skin, a nonlinear finite element method (FEM) was conducted. Experimental results showed that the average pull-out force of the stinger was 113.50mN and the average penetration force was only 5.75mN. The average penetration force of the stinger was about one order of magnitude smaller than that of an acupuncture microneedle while the average pull-out force was about 70 times larger than that of an acupuncture microneedle. FEM results showed that the stress concentrations were around the stinger tip and its barbs during the insertion process. The barbs were jammed in and torn the skin during the pull process. The insertion force of the stinger was greatly minimized due to its ultrasharp stinger tip and barbs while the pull force was seriously enhanced due to the mechanical interlocking of the barbs in the skin. These excellent properties are mainly a result of optimal geometry evolved by nature. Such finding may provide an inspiration for the further design of improved tissue adhesives and micro-needles for painless transdermal drug delivery and bio-signal recording. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Characterization and Effects of Fiber Pull-Outs in Hole Quality of Carbon Fiber Reinforced Plastics Composite.

    Science.gov (United States)

    Alizadeh Ashrafi, Sina; Miller, Peter W; Wandro, Kevin M; Kim, Dave

    2016-10-13

    Hole quality plays a crucial role in the production of close-tolerance holes utilized in aircraft assembly. Through drilling experiments of carbon fiber-reinforced plastic composites (CFRP), this study investigates the impact of varying drilling feed and speed conditions on fiber pull-out geometries and resulting hole quality parameters. For this study, hole quality parameters include hole size variance, hole roundness, and surface roughness. Fiber pull-out geometries are quantified by using scanning electron microscope (SEM) images of the mechanically-sectioned CFRP-machined holes, to measure pull-out length and depth. Fiber pull-out geometries and the hole quality parameter results are dependent on the drilling feed and spindle speed condition, which determines the forces and undeformed chip thickness during the process. Fiber pull-out geometries influence surface roughness parameters from a surface profilometer, while their effect on other hole quality parameters obtained from a coordinate measuring machine is minimal.

  9. MEMS and mil/aero: technology push and market pull

    Science.gov (United States)

    Clifford, Thomas H.

    2001-04-01

    MEMS offers attractive solutions to high-density fluidics, inertial, optical, switching and other demanding military/aerospace (mil/aero) challenges. However, full acceptance must confront the realities of production-scale producibility, verifiability, testability, survivability, as well as long-term reliability. Data on these `..ilities' are crucial, and are central in funding and deployment decisions. Similarly, mil/aero users must highlight specific missions, environmental exposures, and procurement issues, as well as the quirks of its designers. These issues are particularly challenging in MEMS, because of the laws of physics and business economics, as well as the risks of deploying leading-edge technology into no-fail applications. This paper highlights mil/aero requirements, and suggests reliability/qualification protocols, to guide development effort and to reassure mil/aero users that MEMS labs are mindful of the necessary realities.

  10. A Comparison of Push and Pull Techniques for AJAX

    NARCIS (Netherlands)

    Bozdag, E.; Mesbah, A.; Van Deursen, A.

    2007-01-01

    AJAX applications are designed to have high user interactivity and low user-perceived latency. Real-time dynamic web data such as news headlines, stock tickers, and auction updates need to be propagated to the users as soon as possible. However, AJAX still suffers from the limitations of the Web’s

  11. Oblique abdominal muscle activity in response to external perturbations when pushing a cart.

    Science.gov (United States)

    Lee, Yun-Ju; Hoozemans, Marco J M; van Dieën, Jaap H

    2010-05-07

    Cyclic activation of the external and internal oblique muscles contributes to twisting moments during normal gait. During pushing while walking, it is not well understood how these muscles respond to presence of predictable (cyclic push-off forces) and unpredictable (external) perturbations that occur in pushing tasks. We hypothesized that the predictable perturbations due to the cyclic push-off forces would be associated with cyclic muscle activity, while external perturbations would be counteracted by cocontraction of the oblique abdominal muscles. Eight healthy male subjects pushed at two target forces and two handle heights in a static condition and while walking without and with external perturbations. For all pushing tasks, the median, the static (10th percentile) and the peak levels (90th percentile) of the electromyographic amplitudes were determined. Linear models with oblique abdominal EMGs and trunk angles as input were fit to the twisting moments, to estimate trunk stiffness. There was no significant difference between the static EMG levels in pushing while walking compared to the peak levels in pushing while standing. When pushing while walking, the additional dynamic activity was associated with the twisting moments, which were actively modulated by the pairs of oblique muscles as in normal gait. The median and static levels of trunk muscle activity and estimated trunk stiffness were significantly higher when perturbations occurred than without perturbations. The increase baseline of muscle activity indicated cocontraction of the antagonistic muscle pairs. Furthermore, this cocontraction resulted in an increased trunk stiffness around the longitudinal axis. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. Single borehole test sensitivity towards crack and rock parameter. Lesson Hortberg; Einbohrlochtracertestsensitivitaet gegenueber Riss und Gesteinsparametern. Lektion Horstberg

    Energy Technology Data Exchange (ETDEWEB)

    Ghergut, Iulia; Behrens, Horst; Sauter, Martin [Goettingen Univ. (Germany). Angewandte Geologie

    2012-10-16

    The novel experiments of the GeoZentrum Hanover (Hanover, Federal Republic of Germany) on geothermal energy at the well bore Horstberg in the south heath also motivated the accompanying tracertest-mindset to move away from the tracer job stereotypes. For some possible designs at the tracertest at this drilling (forced-gradient divergent push by water fracking of Detfurth perforation, single-screen push-pull at Solling perforation, single-screen push-pull at Detfurth perforation, and so forth) the analysis shows how and why the controlling parameter do not comply with the mental basic pattern of the expectations at the tracertests ('tracertest by crack {yields} characterization of the crack', 'tracer residence time {yields} prognosis of the thermal lifetime').

  13. Bio-mechanical aspects of elite cyclists’ motor system adaptation in process of competition activity

    Directory of Open Access Journals (Sweden)

    A.N. Kolumbet

    2017-10-01

    Full Text Available Purpose; to study the laws of motor structure adaptation of elite cyclists, specializing in 4 km individual pursuit racing on track. Material: in the research 18 elite athletes participated. We studied special aspects of athletes’ coordination structure in experiment, which simulated competition activity. Results: at start segment of distance high speed depends on effectiveness of right leg’s pulling; on pressing and pushing of left leg. At initial stage of distance high efficiency of pedaling is ensured by pressing and pulling of right and left legs. At middle segment high workability depends on movement of right leg; pressing, pulling and pushing of left leg. On finish speed depends by effectiveness of pressing, pulling and moving of right leg; pressing and pulling of left leg. Conclusions: the presented material creates real pre-conditions for development of bio-mechanical models of cyclists’ pedaling technique. The received data can be used for special searching of optimal movement, considering competition tactic. The received results can be used for choosing of means and methods of athletes’ movements’ pedagogic re-constructions.

  14. Fast estimation of the derailment risk of a braking train in curves and turnouts

    NARCIS (Netherlands)

    Burgelman, N.D.M.; Li, Z.; Dollevoet, R.P.B.J.

    2016-01-01

    When a train runs through a turnout or a sharp curve, high lateral forces occur between the wheels and rails. These lateral forces increase when the couplers between the wagons are loaded in compression, i.e., a rear locomotive pushing a train or a front locomotive braking a train. This study

  15. Effects of a carbohydrate and protein recovery beverage on performance in trained weightlifters.

    Directory of Open Access Journals (Sweden)

    Christopher B. Taber

    2017-05-01

    Full Text Available INTRODUCTION: Previous investigations have examined nutrient timing with untrained subject and less is known about effects in trained subjects. OBJECTIVES: The purpose of this study was to examine the effects of a carbohydrate and protein supplement (CHO+PROT on performance measures in trained weightlifters. METHODS: 10 trained weightlifters (30.8±5.1 years, 177.4 ±4.0 cm, 94.3 ± 12.4 kg, training age = 5.3 ± 2.9 years completed a 12 week training program utilizing block periodization. Using a double blind placebo design, jump height, scaled peak power measured in vertical jumps and peak force and rate of force development measured in isometric mid-thigh pulls were compared between groups using a series of 2x4 (group x time repeated measures ANOVA’s. RESULTS: No significant differences (p > 0.05 were observed between treatment and placebo groups in respect to measures of jump height and peak power with weighted and unweighted jumps. Likewise, no statistical differences (p > 0.05 were observed for peak force or rate of force development with isometric mid-thigh pulls. CONCLUSION: These findings indicate that a CHO+PROT supplement provided no additional performance benefits compared to a placebo within a 12 week block periodization protocol in trained weightlifters.

  16. Incorporating pushing in exclusion-process models of cell migration.

    Science.gov (United States)

    Yates, Christian A; Parker, Andrew; Baker, Ruth E

    2015-05-01

    The macroscale movement behavior of a wide range of isolated migrating cells has been well characterized experimentally. Recently, attention has turned to understanding the behavior of cells in crowded environments. In such scenarios it is possible for cells to interact, inducing neighboring cells to move in order to make room for their own movements or progeny. Although the behavior of interacting cells has been modeled extensively through volume-exclusion processes, few models, thus far, have explicitly accounted for the ability of cells to actively displace each other in order to create space for themselves. In this work we consider both on- and off-lattice volume-exclusion position-jump processes in which cells are explicitly allowed to induce movements in their near neighbors in order to create space for themselves to move or proliferate into. We refer to this behavior as pushing. From these simple individual-level representations we derive continuum partial differential equations for the average occupancy of the domain. We find that, for limited amounts of pushing, comparison between the averaged individual-level simulations and the population-level model is nearly as good as in the scenario without pushing. Interestingly, we find that, in the on-lattice case, the diffusion coefficient of the population-level model is increased by pushing, whereas, for the particular off-lattice model that we investigate, the diffusion coefficient is reduced. We conclude, therefore, that it is important to consider carefully the appropriate individual-level model to use when representing complex cell-cell interactions such as pushing.

  17. Push for the Second Screen

    DEFF Research Database (Denmark)

    Sørensen, Jannick Kirk; Sørensen, Lene Tolstrup

    Users’ perception of the relation between the TV screen and a secondary screen (e.g. smartphone or tablet) is examined empirically in a pilot project through a low-fi prototype and interviews. Early observations indicate that the user value/acceptance of push-messages delivered to the second screen...

  18. The effects of biting and pulling on the forces generated during feeding in the Komodo dragon (Varanus komodoensis).

    Science.gov (United States)

    D'Amore, Domenic C; Moreno, Karen; McHenry, Colin R; Wroe, Stephen

    2011-01-01

    In addition to biting, it has been speculated that the forces resulting from pulling on food items may also contribute to feeding success in carnivorous vertebrates. We present an in vivo analysis of both bite and pulling forces in Varanus komodoensis, the Komodo dragon, to determine how they contribute to feeding behavior. Observations of cranial modeling and behavior suggest that V. komodoensis feeds using bite force supplemented by pulling in the caudal/ventrocaudal direction. We tested these observations using force gauges/transducers to measure biting and pulling forces. Maximum bite force correlates with both body mass and total body length, likely due to increased muscle mass. Individuals showed consistent behaviors when biting, including the typical medial-caudal head rotation. Pull force correlates best with total body length, longer limbs and larger postcranial motions. None of these forces correlated well with head dimensions. When pulling, V. komodoensis use neck and limb movements that are associated with increased caudal and ventral oriented force. Measured bite force in Varanus komodoensis is similar to several previous estimations based on 3D models, but is low for its body mass relative to other vertebrates. Pull force, especially in the ventrocaudal direction, would allow individuals to hunt and deflesh with high success without the need of strong jaw adductors. In future studies, pull forces need to be considered for a complete understanding of vertebrate carnivore feeding dynamics.

  19. The Agost Basin (Betic Cordillera, Alicante province, Spain): a pull-apart basin involving salt tectonics

    Science.gov (United States)

    Martín-Martín, Manuel; Estévez, Antonio; Martín-Rojas, Ivan; Guerrera, Francesco; Alcalá, Francisco J.; Serrano, Francisco; Tramontana, Mario

    2018-03-01

    The Agost Basin is characterized by a Miocene-Quaternary shallow marine and continental infilling controlled by the evolution of several curvilinear faults involving salt tectonics derived from Triassic rocks. From the Serravallian on, the area experienced a horizontal maximum compression with a rotation of the maximum stress axis from E-W to N-S. The resulting deformation gave rise to a strike-slip fault whose evolution is characterized progressively by three stages: (1) stepover/releasing bend with a dextral motion of blocks; (2) very close to pure horizontal compression; and (3) restraining bend with a sinistral movement of blocks. In particular, after an incipient fracturing stage, faults generated a pull-apart basin with terraced sidewall fault and graben subzones developed in the context of a dextral stepover during the lower part of late Miocene p.p. The occurrence of Triassic shales and evaporites played a fundamental role in the tectonic evolution of the study area. The salty material flowed along faults during this stage generating salt walls in root zones and salt push-up structures at the surface. During the purely compressive stage (middle part of late Miocene p.p.) the salt walls were squeezed to form extrusive mushroom-like structures. The large amount of clayish and salty material that surfaced was rapidly eroded and deposited into the basin, generating prograding fan clinoforms. The occurrence of shales and evaporites (both in the margins of the basin and in the proper infilling) favored folding of basin deposits, faulting, and the formation of rising blocks. Later, in the last stage (upper part of late Miocene p.p.), the area was affected by sinistral restraining conditions and faults must have bent to their current shape. The progressive folding of the basin and deformation of margins changed the supply points and finally caused the end of deposition and the beginning of the current erosive systems. On the basis of the interdisciplinary results

  20. Environmental labelling as a marketing concept to create added value for flower chains: How to create a horticultural chain based on responsive consumer information

    NARCIS (Netherlands)

    Dam, van Y.K.; Lans, van der I.A.; Zimmerman, K.L.

    2004-01-01

    We investigated the possibility to create markets for environmentally friendly grown flowers and plants by combining a push and a pull strategy. Consumer research revealed that the main pull should come from a target segment (one-fifth of the population) of heavy flower users that are either

  1. Approach and avoidance in fear of spiders

    NARCIS (Netherlands)

    Rinck, M.; Becker, E.S.

    2007-01-01

    We examined attitudes towards spiders by employing an Approach-Avoidance Task, in which participants respond to pictures by pulling a joystick towards themselves or by pushing it away from themselves. For spider fearfuls, this stimulus–response assignment is either compatible (push spiders away) or

  2. Investigation of the Effect of Internal Mold Release Agent and Filler on the Pulling Force in Pultrusion Process

    Directory of Open Access Journals (Sweden)

    M. Esfandeh

    2007-08-01

    Full Text Available Pulling force is one of the most important variables in pultrusion process which determines the capacity of the pultrusion machine. One of the characteristics of a desired pultrusion process is a low pulling force and a high line speed.Among the important factors affecting the pulling force are the internal mold release agent (IMR and the content and particle size of the filler in resin formulation. In addition to facilitating the part separation from the die, IMR also affects the curing kinetics and in turn the pulling force. In this research, a commercial IMR has been used in a range 1-5 phr. DSC and DMTAAnalyses showed that the presence of IMR in concentrations above 3 phr reduces the heat of curing reaction and also the curing rate. This results in an increase in pulling force. Study of filler effect showed that the increase in filler content from 4 to 8 phr reduces the pulling force but beyond that it is increased. Also, decreasing the filler particle size in line speed lower than 30 cm/min reduces the pulling force but increases it at higher line speed.

  3. Placement of effective work-in-progress limits in route-specific unit-based pull systems

    NARCIS (Netherlands)

    Ziengs, N.; Riezebos, J.; Germs, R.

    2012-01-01

    Unit-based pull systems control the throughput time of orders in a production system by limiting the number of orders on the shop floor. In production systems where orders can follow different routings on the shop floor, route-specific pull systems that control the progress of orders on the shop

  4. Pull-in and wrinkling instabilities of electroactive dielectric actuators

    International Nuclear Information System (INIS)

    De Tommasi, D; Puglisi, G; Zurlo, G; Saccomandi, G

    2010-01-01

    We propose a model to analyse the insurgence of pull-in and wrinkling failures in electroactive thin films. We take into consideration both cases of voltage and charge control, the role of pre-stretch and the size of activated regions, which are all crucial factors in technological applications of electroactive polymers (EAPs). Based on simple geometrical and material assumptions we deduce an explicit analytical description of these phenomena, allowing a clear physical interpretation of different failure mechanisms such as the occurrence of pull-in and wrinkling. Despite our simple assumptions, the comparison with experiments shows a good qualitative and, interestingly, quantitative agreement. In particular our model shows, in accordance with experiments, the existence of different optimal pre-stretch values, depending on the choice of the actuating parameter of the EAP.

  5. Pull-in and wrinkling instabilities of electroactive dielectric actuators

    Energy Technology Data Exchange (ETDEWEB)

    De Tommasi, D; Puglisi, G; Zurlo, G [Dipartimento di Ingegneria Civile e Ambientale, Politecnico di Bari, 70125 Bari (Italy); Saccomandi, G [Dipartimento di Ingegneria Industriale, Universita degli Studi di Perugia, 06125 Perugia (Italy)

    2010-08-18

    We propose a model to analyse the insurgence of pull-in and wrinkling failures in electroactive thin films. We take into consideration both cases of voltage and charge control, the role of pre-stretch and the size of activated regions, which are all crucial factors in technological applications of electroactive polymers (EAPs). Based on simple geometrical and material assumptions we deduce an explicit analytical description of these phenomena, allowing a clear physical interpretation of different failure mechanisms such as the occurrence of pull-in and wrinkling. Despite our simple assumptions, the comparison with experiments shows a good qualitative and, interestingly, quantitative agreement. In particular our model shows, in accordance with experiments, the existence of different optimal pre-stretch values, depending on the choice of the actuating parameter of the EAP.

  6. Comparison of delayed versus immediate pushing during second stage of labor for nulliparous women with epidural anesthesia.

    Science.gov (United States)

    Gillesby, Erica; Burns, Suzan; Dempsey, Amy; Kirby, Shirley; Mogensen, Kami; Naylor, Kelly; Petrella, Joann; Vanicelli, Rebecca; Whelan, Breon

    2010-01-01

    To determine if the use of delayed pushing after the onset of the second stage of labor decreases the time of active pushing and decreases maternal fatigue. Randomized clinical trial. Labor and delivery unit of a not-for-profit community hospital. Convenience sample of nulliparous laboring women with epidural anesthesia. Immediate or delayed pushing (2 hours) during the second stage of labor at the time of complete cervical dilatation. The length of pushing, total length of the second stage, and maternal fatigue. A total of 77 women were studied (immediate pushing group=39; delayed pushing=38). The immediate pushing group averaged 94 (± 57) minutes in active pushing, while the delayed pushing group averaged 68 (± 46) minutes, a statistically significant difference (p=.04). No significant differences were found in fatigue scores between the immediate and delayed pushing groups (p>.05). We found that by delaying the onset of active pushing for 2 hours after the beginning of the second stage of labor, the time that nulliparous women with epidural anesthesia spent in active pushing was significantly decreased by 27%. Although the delayed pushing group rested for up to 2 hours, the total time in the second stage of labor averaged only 59 minutes longer than the immediate pushing group. © 2010 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

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

    Science.gov (United States)

    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. Range of Motion of the Ankle According to Pushing Force, Gender and Knee Position.

    Science.gov (United States)

    Cho, Kang Hee; Jeon, Yumi; Lee, Hyunkeun

    2016-04-01

    To investigate the difference of range of motion (ROM) of ankle according to pushing force, gender and knee position. One hundred and twenty-eight healthy adults (55 men, 73 women) between the ages of 20 and 51, were included in the study. One examiner measured the passive range of motion (PROM) of ankle by Dualer IQ Inclinometers and Commander Muscle Testing. ROM of ankle dorsiflexion (DF) and plantarflexion (PF) according to change of pushing force and knee position were measured at prone position. There was significant correlation between ROM and pushing force, the more pushing force leads the more ROM at ankle DF and ankle PF. Knee flexion of 90° position showed low PF angle and high ankle DF angle, as compared to the at neutral position of knee joint. ROM of ankle DF for female was greater than for male, with no significant difference. ROM of ankle PF for female was greater than male regardless of the pushing force. To our knowledge, this is the first study to assess the relationship between pushing force and ROM of ankle joint. There was significant correlation between ROM of ankle and pushing force. ROM of ankle PF for female estimated greater than male regardless of the pushing force and the number of measurement. The ROM of the ankle is measured differently according to the knee joint position. Pushing force, gender and knee joint position are required to be considered when measuring the ROM of ankle joint.

  9. UK pulls out of plans for ILC

    CERN Multimedia

    Durrani, Matin

    2007-01-01

    "A funding crisis at one of the UK's leading research councils has forced the country to pull out of plans for the International Linear Collider (ILC). The science and Technology Facilities Council (STFC) says in a report published today that it does not see "a practicable path towards the realization of this facility as currently conceived on a reasonable timescale". (1 page)

  10. The effects of biting and pulling on the forces generated during feeding in the Komodo dragon (Varanus komodoensis.

    Directory of Open Access Journals (Sweden)

    Domenic C D'Amore

    Full Text Available In addition to biting, it has been speculated that the forces resulting from pulling on food items may also contribute to feeding success in carnivorous vertebrates. We present an in vivo analysis of both bite and pulling forces in Varanus komodoensis, the Komodo dragon, to determine how they contribute to feeding behavior. Observations of cranial modeling and behavior suggest that V. komodoensis feeds using bite force supplemented by pulling in the caudal/ventrocaudal direction. We tested these observations using force gauges/transducers to measure biting and pulling forces. Maximum bite force correlates with both body mass and total body length, likely due to increased muscle mass. Individuals showed consistent behaviors when biting, including the typical medial-caudal head rotation. Pull force correlates best with total body length, longer limbs and larger postcranial motions. None of these forces correlated well with head dimensions. When pulling, V. komodoensis use neck and limb movements that are associated with increased caudal and ventral oriented force. Measured bite force in Varanus komodoensis is similar to several previous estimations based on 3D models, but is low for its body mass relative to other vertebrates. Pull force, especially in the ventrocaudal direction, would allow individuals to hunt and deflesh with high success without the need of strong jaw adductors. In future studies, pull forces need to be considered for a complete understanding of vertebrate carnivore feeding dynamics.

  11. Approaching contamination-related stimuli with an implicit Approach-Avoidance Task: Can it reduce OCD symptoms? An online pilot study.

    Science.gov (United States)

    Weil, Ricarda; Feist, Ansgar; Moritz, Steffen; Wittekind, Charlotte E

    2017-12-01

    Dual-process models suggest that automatic behavioral tendencies contribute to the development and maintenance of Obsessive Compulsive Disorder (OCD) symptoms. The aim of the present study was to investigate the potential of the Approach-Avoidance Task (AAT) to reduce OCD symptoms and associated distress. The study was set up as an online intervention. Participants with OCD symptoms (N = 101) were randomly assigned either to one of two experimental conditions or a waitlist control group upon completion of an online baseline survey. Participants were instructed to respond to contamination-related and neutral pictures by pulling or pushing a computer mouse, respectively. In one AAT condition, contamination-relevant pictures remained on the screen one second after pulling (lock condition), while pictures disappeared immediately after pulling in the standard AAT. Participants completed an online re-assessment four weeks after baseline. For analyses, only data of patients with contamination-related OCD symptoms were analyzed. A significant reduction in distress caused by OCD symptoms was found for both AAT training groups. Furthermore, a reduction in compulsions occurred for the group using the standard AAT. No significant effect was found for the control group. Implicit behavioral tendencies prior to and after training were not assessed. Findings tentatively suggest that the AAT might be effective in reducing washing-/contamination-related OCD symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Nonlinear Finite Element Analysis of Pull-Out Test

    DEFF Research Database (Denmark)

    Saabye Ottesen, N

    1981-01-01

    A specific pull-out test used to determine in-situ concrete compressive strength is analyzed. This test consists of a steel disc that is extracted from the structure. The finite element analysis considers cracking as well as strain hardening and softening in the pre- and post-failure region...

  13. Effects of asymmetrical stance and movement on body rotation in pushing.

    Science.gov (United States)

    Lee, Yun-Ju; Aruin, Alexander S

    2015-01-21

    Pushing objects in the presence of body asymmetries could increase the risk of back injury. Furthermore, when the object is heavy, it could exacerbate the effects induced by asymmetrical posture. We investigated how the use of asymmetrical posture and/or upper extremity movement affect vertical torque (Tz) and center of pressure (COP) displacement during pushing. Ten healthy volunteers were instructed to push objects of three different weights using two hands (symmetrical hand use) or one hand (asymmetrical hand use) while standing in symmetrical or asymmetrical foot-positions. The peak values of Tz and COP displacement in the medial-lateral direction (COPML) were analyzed. In cases of isolated asymmetry, changes in the Tz were mainly linked with effects of hand-use whereas effects of foot-position dominated changes in the COPML displacement. In cases of a combined asymmetry, the magnitudes of both Tz and COPML were additive when asymmetrical hand-use and foot-position induced the rotation of the lower and upper body in the same direction or subtractive when asymmetries resulted in the rotation of the body segments in the opposite directions. Moreover, larger Tz and COP displacements were seen when pushing the heavy weight. The results point out the importance of using Tz and COPML to describe the isolated or combined effects of asymmetrical upper extremity movement and asymmetrical posture on body rotation during pushing. Furthermore, it suggests that a proper combination of unilateral arm movement and foot placements could help to reduce body rotation even when pushing heavy objects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The Effect of Coconut Oil pulling on Streptococcus mutans Count in Saliva in Comparison with Chlorhexidine Mouthwash.

    Science.gov (United States)

    Kaushik, Mamta; Reddy, Pallavi; Sharma, Roshni; Udameshi, Pooja; Mehra, Neha; Marwaha, Aditya

    2016-01-01

    Oil pulling is an age-old practice that has gained modern popularity in promoting oral and systemic health. The scientific verification for this practice is insufficient. Thus, this study evaluated the effect of coconut oil pulling on the count of Streptococcus mutans in saliva and to compare its efficacy with that of Chlorhexidine mouthwash: in vivo. The null hypothesis was that coconut oil pulling has no effect on the bacterial count in saliva. A randomized controlled study was planned and 60 subjects were selected. The subjects were divided into three groups, Group A: Oil pulling, Group B: Chlorhexidine, and Group C: Distilled water. Group A subjects rinsed mouth with 10 ml of coconut oil for 10 minutes. Group B subjects rinsed mouth with 5 ml Chlorhexidine mouthwash for 1 minute and Group C with 5 ml distilled water for 1 minute in the morning before brushing. Saliva samples were collected and cultured on 1st day and after 2 weeks from all subjects. Colonies were counted to compare the efficacy of coconut oil and Chlorhexidine with distilled water. Statistically significant reduction in S. mutans count was seen in both the coconut oil pulling and Chlorhexidine group. Oil pulling can be explored as a safe and effective alternative to Chlorhexidine. Edible oil-pulling therapy is natural, safe and has no side effects. Hence, it can be considered as a preventive therapy at home to maintain oral hygiene.

  15. Psychophysically determined forces of dynamic pushing for female industrial workers: Comparison of two apparatuses.

    Science.gov (United States)

    Ciriello, Vincent M; Maikala, Rammohan V; Dempsey, Patrick G; O'Brien, Niall V

    2010-01-01

    Using psychophysics, the maximum acceptable forces for pushing have been previously developed using a magnetic particle brake (MPB) treadmill at the Liberty Mutual Research Institute for Safety. The objective of this study was to investigate the reproducibility of maximum acceptable initial and sustained forces while performing a pushing task at a frequency of 1min(-1) both on a MPB treadmill and on a high-inertia pushcart. This is important because our pushing guidelines are used extensively as a ergonomic redesign strategy and we would like the information to be as applicable as possible to cart pushing. On two separate days, nineteen female industrial workers performed a 40-min MPB treadmill pushing task and a 2-hr pushcart task, in the context of a larger experiment. During pushing, the subjects were asked to select a workload they could sustain for 8h without "straining themselves or without becoming unusually tired, weakened, overheated or out of breath." The results demonstrated that maximum acceptable initial and sustained forces of pushing determined on the high inertia pushcart were 0.8% and 2.5% lower than the MPB treadmill. The results also show that the maximum acceptable sustained force of the MPB treadmill task was 0.5% higher than the maximum acceptable sustained force of Snook and Ciriello (1991). Overall, the findings confirm that the existing pushing data developed by the Liberty Mutual Research Institute for Safety still provides an accurate estimate of maximal acceptable forces for the selected combination of distance and frequency of push for female industrial workers.

  16. The defence technique in Tai Chi Push Hands: a case study.

    Science.gov (United States)

    Chen, Hui-Chuan; Cheng, Kuang-You B; Liu, Yu-Jen; Chiu, Hung-Ta; Cheng, Kuang-Yu

    2010-12-01

    Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force.

  17. Optical micromanipulation of active cells with minimal perturbations: direct and indirect pushing.

    Science.gov (United States)

    Wang, Chenlu; Chowdhury, Sagar; Gupta, Satyandra K; Losert, Wolfgang

    2013-04-01

    The challenge to wide application of optical tweezers in biological micromanipulation is the photodamage caused by high-intensity laser exposure to the manipulated living systems. While direct exposure to infrared lasers is less likely to kill cells, it can affect cell behavior and signaling. Pushing cells with optically trapped objects has been introduced as a less invasive alternative, but the technique includes some exposure of the biological object to parts of the optical tweezer beam. To keep the cells farther away from the laser, we introduce an indirect pushing-based technique for noninvasive manipulation of sensitive cells. We compare how cells respond to three manipulation approaches: direct manipulation, pushing, and indirect pushing. We find that indirect manipulation techniques lessen the impact of manipulation on cell behavior. Cell survival increases, as does the ability of cells to maintain shape and wiggle. Our experiments also demonstrate that indirect pushing allows cell-cell contacts to be formed in a controllable way, while retaining the ability of cells to change shape and move.

  18. (Close) distance makes the heart grow fonder:Improving implicit racial attitudes and interracial interactions through approach behaviors.

    Science.gov (United States)

    Kawakami, Kerry; Phills, Curtis E; Steele, Jennifer R; Dovidio, John F

    2007-06-01

    In 4 studies, the authors examined the effect of approaching Blacks on implicit racial attitudes and immediacy behaviors. In Studies 1-3, participants were trained to pull a joystick toward themselves or to push it away from themselves when presented with photographs of Blacks, Whites, or Asians before completing an Implicit Association Test to measure racial bias. In Study 4, the effect of this training procedure on nonverbal behavior in an interracial contact situation was investigated. Results from the studies demonstrated that approaching Blacks decreased participants' implicit racial prejudice and increased immediacy when interacting with a Black confederate. The implications of these findings for current theories on approach, avoidance, and intergroup relations are discussed. (c) 2007 APA, all rights reserved.

  19. Stroller running: Energetic and kinematic changes across pushing methods.

    Science.gov (United States)

    Alcantara, Ryan S; Wall-Scheffler, Cara M

    2017-01-01

    Running with a stroller provides an opportunity for parents to exercise near their child and counteract health declines experienced during early parenthood. Understanding biomechanical and physiological changes that occur when stroller running is needed to evaluate its health impact, yet the effects of stroller running have not been clearly presented. Here, three commonly used stroller pushing methods were investigated to detect potential changes in energetic cost and lower-limb kinematics. Sixteen individuals (M/F: 10/6) ran at self-selected speeds for 800m under three stroller conditions (2-Hands, 1-Hand, and Push/Chase) and an independent running control. A significant decrease in speed (p = 0.001) and stride length (ppushing method had a significant effect on speed (p = 0.001) and stride length (ppushing technique influences stroller running speed and kinematics. These findings suggest specific fitness effects may be achieved through the implementation of different pushing methods.

  20. Maternal and Neonatal Outcomes With Early Compared With Delayed Pushing Among Nulliparous Women.

    Science.gov (United States)

    Yee, Lynn M; Sandoval, Grecio; Bailit, Jennifer; Reddy, Uma M; Wapner, Ronald J; Varner, Michael W; Caritis, Steve N; Prasad, Mona; Tita, Alan T N; Saade, George; Sorokin, Yoram; Rouse, Dwight J; Blackwell, Sean C; Tolosa, Jorge E

    2016-11-01

    To describe factors associated with delayed pushing and evaluate the relationship between delayed pushing and perinatal outcomes in nulliparous women with singleton term gestations. This was a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Assessment of Perinatal Excellence cohort of 115,502 women and their neonates born in 25 U.S. hospitals from 2008 to 2011. Nulliparous women with singleton, cephalic, nonanomalous term births who achieved 10-cm cervical dilation were included. Women in whom pushing was delayed by 60 minutes or greater (delayed group) were compared with those who initiated pushing within 30 minutes (early group). Multivariable regression analyses were used to assess the independent association of delayed pushing with mode of delivery, length of the second stage, and other maternal and perinatal outcomes (significance defined as Ppushing was delayed in 18.4% (n=3,870). Women who were older, privately insured, or non-Hispanic white as well as those who had induction or augmentation of labor, diabetes, or epidural analgesia were more likely to have delayed pushing. Delayed pushing was more common when the second stage began during daytime hours or in hospitals with dedicated 24-hour obstetric anesthesia, although differences were small. After adjusting for differences in baseline and labor characteristics including center, women in the delayed group had longer mean durations of the second stage (191 compared with 84 minutes, Ppushing (86 compared with 76 minutes, Ppushing was associated with greater rates of cesarean delivery (11.2% compared with 5.1%; adjusted odds ratio [OR] 1.86, 95% confidence interval [CI] 1.63-2.12), operative vaginal delivery (adjusted OR 1.26, 95% CI 1.14-1.40), postpartum hemorrhage (adjusted OR 1.43, 95% CI 1.05-1.95), and blood transfusion (adjusted OR 1.51, 95% CI 1.04-2.17). Delayed pushing was not associated with increased odds of adverse neonatal outcomes

  1. RF Bead Pull Measurements of the DQW

    CERN Document Server

    Jaume, Guillaume

    2015-01-01

    This report was written within the framework of the CERN Summer Student Program. It is focused on the Radio Frequency study of the Double Quarter Wave Crab Cavity [1] considered for the crab-crossing scheme of the LHC Luminosity upgrade [2]. HFSS simulation [3] and Bead-Pull Measurements technique were used for the characterization of the higher-order terms of the main deflecting mode.

  2. Effects of Different Relative Loads on Power Performance During the Ballistic Push-up.

    Science.gov (United States)

    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 ballistic push-up, regardless of the participants' level of strength.

  3. DC dynamic pull-in instability of a dielectric elastomer balloon: an energy-based approach

    Science.gov (United States)

    Sharma, Atul Kumar; Arora, Nitesh; Joglekar, M. M.

    2018-03-01

    This paper reports an energy-based method for the dynamic pull-in instability analysis of a spherical dielectric elastomer (DE) balloon subjected to a quasi-statically applied inflation pressure and a Heaviside step voltage across the balloon wall. The proposed technique relies on establishing the energy balance at the point of maximum stretch in an oscillation cycle, followed by the imposition of an instability condition for extracting the threshold parameters. The material models of the Ogden family are employed for describing the hyperelasticity of the balloon. The accuracy of the critical dynamic pull-in parameters is established by examining the saddle-node bifurcation in the transient response of the balloon obtained by integrating numerically the equation of motion, derived using the Euler-Lagrange equation. The parametric study brings out the effect of inflation pressure on the onset of the pull-in instability in the DE balloon. A quantitative comparison between the static and dynamic pull-in parameters at four different levels of the inflation pressure is presented. The results indicate that the dynamic pull-in instability gets triggered at electric fields that are lower than those corresponding to the static instability. The results of the present investigation can find potential use in the design and development of the balloon actuators subjected to transient loading. The method developed is versatile and can be used in the dynamic instability analysis of other conservative systems of interest.

  4. Effect of the yarn pull-out velocity of shear thickening fluid-impregnated Kevlar fabric on the coefficient of friction

    Energy Technology Data Exchange (ETDEWEB)

    Aikarami, Sh [Dept. of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Kordani, N. [Dept. of Mechanical Engineering, University of Mazandaran, Mazandaran (Iran, Islamic Republic of); Sadough, Vanini A. [Dept. of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Amiri, H. [Technical Campus, Tehran South Branch, Islamic Azad University, Tehran(Iran, Islamic Republic of)

    2016-08-15

    This study explains the yarn pull-out process behavior of woven fabrics in relation to their mechanical properties. Empirical research on the relationship between the yarn pull-out behavior and fabric properties are evaluated, along with a detailed comparison of friction between the fabric fibers in static and dynamic modes. Samples are tested in three modes, namely, neat, dissolved liquid, and silica particle- based Shear thickening fluid (STF)-treated fabric. Accordingly, the presence of STF increases friction between the fabrics and the warp and weft yarns, as well as prevents the displacement of the yarns. Increased friction also leads to an increase in the energy absorption of the yarn pull-out process. In this research, the pull-out test has been performed at three different velocities: 50, 250 and 500 mm/min. Results show that increases in the pull-out velocity increase the pull-out force of the neat and dissolved liquid samples. By contrast, the behavior is completely opposite in the STF-treated sample. Comparing the yarn pull-out values indicates that the STF-treated samples have the highest value, which is approximately three times higher than that of the neat sample.

  5. Effect of the yarn pull-out velocity of shear thickening fluid-impregnated Kevlar fabric on the coefficient of friction

    International Nuclear Information System (INIS)

    Aikarami, Sh; Kordani, N.; Sadough, Vanini A.; Amiri, H.

    2016-01-01

    This study explains the yarn pull-out process behavior of woven fabrics in relation to their mechanical properties. Empirical research on the relationship between the yarn pull-out behavior and fabric properties are evaluated, along with a detailed comparison of friction between the fabric fibers in static and dynamic modes. Samples are tested in three modes, namely, neat, dissolved liquid, and silica particle- based Shear thickening fluid (STF)-treated fabric. Accordingly, the presence of STF increases friction between the fabrics and the warp and weft yarns, as well as prevents the displacement of the yarns. Increased friction also leads to an increase in the energy absorption of the yarn pull-out process. In this research, the pull-out test has been performed at three different velocities: 50, 250 and 500 mm/min. Results show that increases in the pull-out velocity increase the pull-out force of the neat and dissolved liquid samples. By contrast, the behavior is completely opposite in the STF-treated sample. Comparing the yarn pull-out values indicates that the STF-treated samples have the highest value, which is approximately three times higher than that of the neat sample

  6. Optical pulling of airborne absorbing particles and smut spores over a meter-scale distance with negative photophoretic force

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jinda; Hart, Adam G.; Li, Yong-qing, E-mail: liy@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353 (United States)

    2015-04-27

    We demonstrate optical pulling of single light-absorbing particles and smut spores in air over a meter-scale distance using a single collimated laser beam based on negative photophoretic force. The micron-sized particles are pulled towards the light source at a constant speed of 1–10 cm/s in the optical pulling pipeline while undergoing transverse rotation at 0.2–10 kHz. The pulled particles can be manipulated and precisely positioned on the entrance window with an accuracy of ∼20 μm, and their chemical compositions can be characterized with micro-Raman spectroscopy.

  7. Fast Pulling of n-Type Si Ingots for Enhanced Si Solar Cell Production

    Science.gov (United States)

    Kim, Kwanghun; Park, Sanghyun; Park, Jaechang; Pang, Ilsun; Ryu, Sangwoo; Oh, Jihun

    2018-03-01

    Reducing the manufacturing costs of silicon substrates is an important issue in the silicon-based solar cell industry. In this study, we developed a high-throughput ingot growth method by accelerating the pulling speed in the Czochralski process. By controlling the heat flow of the ingot growth chamber and at the solid-liquid interfaces, the pulling speed of an ingot could be increased by 15% compared to the conventional method, while retaining high quality. The wafer obtained at a high pulling speed showed an enhanced minority carrier lifetime compared with conventional wafers, due to the vacancy passivation effect, and also demonstrated comparable bulk resistivity and impurities. The results in this work are expected to open a new way to enhance the productivity of Si wafers used for Si solar cells, and therefore, to reduce the overall manufacturing cost.

  8. Pick-N-Pull Auto Dismantlers, Kansas City, LLC Inc.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Pick-N-Pull Auto Dismantlers, Kansas City, LLC, a subsidiary of Schnitzer Steel Industries, Inc., for alleged violations at its facilities at 8012 East Truman Rd., Kansas C

  9. Force-velocity properties' contribution to bilateral deficit during ballistic push-off.

    Science.gov (United States)

    Samozino, Pierre; Rejc, Enrico; di Prampero, Pietro Enrico; Belli, Alain; Morin, Jean-Benoît

    2014-01-01

    The objective of this study is to quantify the contribution of the force-velocity (F-v) properties to bilateral force deficit (BLD) in ballistic lower limb push-off and to relate it to individual F-v mechanical properties of the lower limbs. The F-v relation was individually assessed from mechanical measurements for 14 subjects during maximal ballistic lower limb push-offs; its contribution to BLD was then investigated using a theoretical macroscopic approach, considering both the mechanical constraints of movement dynamics and the maximal external capabilities of the lower limb neuromuscular system. During ballistic lower limb push-off, the maximum force each lower limb can produce was lower during bilateral than unilateral actions, thus leading to a BLD of 36.7% ± 5.7%. The decrease in force due to the F-v mechanical properties amounted to 19.9% ± 3.6% of the force developed during BL push-offs, which represents a nonneural contribution to BLD of 43.5% ± 9.1%. This contribution to BLD that cannot be attributed to changes in neural features was negatively correlated to the maximum unloaded extension velocity of the lower limb (r = -0.977, P push-off, BLD is due to both neural alterations and F-v mechanical properties, the latter being associated with the change in movement velocity between bilateral and unilateral actions. The level of the contribution of the F-v properties depends on the individual F-v mechanical profile of the entire lower limb neuromuscular system: the more the F-v profile is oriented toward velocity capabilities, the lower the loss of force from unilateral to bilateral push-offs due to changes in movement velocity.

  10. The pulling power of chocolate: Effects of approach-avoidance training on approach bias and consumption.

    Science.gov (United States)

    Dickson, Hugh; Kavanagh, David J; MacLeod, Colin

    2016-04-01

    Previous research has shown that action tendencies to approach alcohol may be modified using computerized Approach-Avoidance Task (AAT), and that this impacted on subsequent consumption. A recent paper in this journal (Becker, Jostman, Wiers, & Holland, 2015) failed to show significant training effects for food in three studies: Nor did it find effects on subsequent consumption. However, avoidance training to high calorie foods was tested against a control rather than Approach training. The present study used a more comparable paradigm to the alcohol studies. It randomly assigned 90 participants to 'approach' or 'avoid' chocolate images on the AAT, and then asked them to taste and rate chocolates. A significant interaction of condition and time showed that training to avoid chocolate resulted in faster avoidance responses to chocolate images, compared with training to approach it. Consistent with Becker et al.'s Study 3, no effect was found on amounts of chocolate consumed, although a newly published study in this journal (Schumacher, Kemps, & Tiggemann, 2016) did do so. The collective evidence does not as yet provide solid basis for the application of AAT training to reduction of problematic food consumption, although clinical trials have yet to be conducted. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  12. Methods of pushing during vaginal delivery and pelvic floor and perineal outcomes: a review.

    Science.gov (United States)

    de Tayrac, Renaud; Letouzey, Vincent

    2016-12-01

    Over the past 20 years, several randomized studies have compared Valsalva and spontaneous pushing techniques during vaginal delivery. This review summarizes current medical knowledge concerning their maternal and fetal consequences, focusing on pelvic and perineal outcomes. We selected nine randomized controlled trials comparing Valsalva and spontaneous pushing, and a secondary analysis of a randomized controlled trial comparing different methods of perineal protection. Two trials showed that spontaneous pushing reduces the risk of perineal tears, but no firm conclusions can be drawn given the heterogeneity and inconsistent results of these studies. Conflicting results have been reported regarding the duration of the second stage of labor. Pushing technique does not seem to affect episiotomy, instrumental delivery or cesarean rates. Maternal satisfaction seems to be better after spontaneous pushing. Spontaneous pushing appears to have no adverse effects on neonatal well being, and one study showed a significant improvement in prenatal fetal parameters during the expulsive phase. Valsalva and spontaneous pushing techniques currently appear comparable in terms of duration, pelvic floor, perineal, and neonatal outcomes. In the absence of strong evidence in favor of either technique, the decision should be guided by patient preference and the clinical situation. Additional, well-designed randomized controlled trials are required.

  13. Cavity Pull Rod: Device to Promote Single Crystal Growth from the Melt

    Science.gov (United States)

    Goldsby, Jon (Inventor)

    2017-01-01

    A pull rod for use in producing a single crystal from a molten alloy is provided that includes an elongated rod having a first end and a second end, a first cavity defined at the first end and a second cavity defined at the first end and in communication with the first cavity. The first cavity receives the molten alloy and the second cavity vents a gas from the molten alloy to thereby template a single crystal when the pull rod is dipped into and extracted from the molten alloy.

  14. Malfunctioning Plastic Biliary Endoprosthesis: Percutaneous Transhepatic Balloon Pulling Technique

    Directory of Open Access Journals (Sweden)

    Umberto G. Rossi

    2013-01-01

    Full Text Available Percutaneous transhepatic removal techniques for malfunctioning plastic biliary endoprosthesis are considered safe and efficient second-line strategies, when endoscopic procedures are not feasible. We describe the percutaneous transhepatic balloon pulling technique in a patient with an unresectable malignant hilar cholangiocarcinoma.

  15. Staying Alive! Training High-Risk Teams for Self Correction

    Science.gov (United States)

    Slack, Kelley; Noe, Raymond; Weaver, Sallie

    2011-01-01

    Research examining teams working in high-risk operations has been lacking. The present symposium showcases research on team training that helps to optimize team performance in environments characterized by life or death situations arising spontaneously after long periods of mundane activity by pulling experts from diverse areas of industry: space flight, health care, and medical simulation.

  16. Cyclic biomechanical testing of biocomposite lateral row knotless anchors in a human cadaveric model.

    Science.gov (United States)

    Barber, F Alan; Bava, Eric D; Spenciner, David B; Piccirillo, Justin

    2013-06-01

    The purpose of this study was to assess the mechanical performance of biocomposite knotless lateral row anchors based on both anchor design and the direction of pull. Two lateral row greater tuberosity insertion sites (anterior and posterior) were identified in matched pairs of fresh-frozen human cadaveric shoulders DEXA (dual energy X-ray absorptiometry) scanned to verify comparability. The humeri were stripped of all soft tissue and 3 different biocomposite knotless lateral row anchors: HEALIX Knotless BR (DePuy Mitek, Raynham MA), BioComposite PushLock (Arthrex, Naples, FL), and Bio-SwiveLock (Arthrex). Fifty-two anchors were distributed among the insertion locations and tested them with either an anatomic or axial pull. A fixed-gauge loop (15 mm) of 2 high-strength sutures from each anchor was created. After a 10-Nm preload, anchors were cycled from 10 to 45 Nm at 0.5 Hz for 200 cycles and tested to failure at 4.23 mm/second. The load to reach 3 mm and 5 mm displacement, ultimate failure load, displacement at ultimate failure, and failure mode were recorded. Threaded anchors (Bio-SwiveLock, P = .03; HEALIX Knotless, P = .014) showed less displacement with anatomic testing than did the nonthreaded anchor (BioComposite PushLock), and the HEALIX Knotless showed less overall displacement than did the other 2 anchors. The Bio-SwiveLock exhibited greater failure loads than did the other 2 anchors (P < .05). Comparison of axial and anatomic loading showed no maximum load differences for all anchors as a whole (P = .1084). Yet, anatomic pulling produced higher failure loads than did axial pulling for the Bio-SwiveLock but not for the BioComposite PushLock or the HEALIX Knotless. The nonthreaded anchor (BioComposite PushLock) displayed lower failure loads than did both threaded anchors with axial pulling. Threaded biocomposite anchors (HEALIX Knotless BR and Bio-SwiveLock) show less anatomic loading displacement and higher axial failure loads than do the nonthreaded

  17. Commercial Scholarship: Spinning Physics Research into a Business Enterprise

    Science.gov (United States)

    Butler, Orville

    2013-03-01

    The American Institute of Physics' Center for History of Physics has conducted a three year NSF funded study of physicist entrepreneurs during which we interviewed 140 physicists who have founded ninety-one startups. Forty of those companies have spun research out of twenty-some universities. Startups spun out of university research tend to be technology push companies, creating new potentially disruptive technologies for which markets do not yet clearly exist, in contrast to market pull companies founded to address innovations responding to market demands. This paper addresses the unique issues found in university spinout companies and their responses to them. While technology push companies are generally considered to be higher risk compared to market pull companies, the university spinouts in our study had a higher rate of both SBIR and venture capital funding than did the market pull companies in our study.

  18. How does the duration of active pushing in labor affect neonatal outcomes?

    Science.gov (United States)

    Yli, Branka M; Kro, Grete A Birkeland; Rasmussen, Svein; Khoury, Janette; Norèn, Håkan; Amer-Wåhlin, Isis; Saugstad, Ola Didrik; Stray-Pedersen, Babill

    2011-11-19

    To assess the effect of time of active pushing (TAP) on neonatal outcome. The study population (n=36,432) was taken from a Swedish randomized control trial on intrapartum monitoring, a European Union fetal electrocardiogram trial, and from Mölndal Hospital. After validation of acid-base samples and TAP, 22,812 cases were accepted for analysis. The median active TAP was 36 min for P0 and 13 min for P≥1 (Ppushing for 15-29 min (n=6589) relative to pushing for 12 mmol/L to 3.5 (95% CI 1.3-9.0). The group with a cord artery pH of 15 min), while the probability of a spontaneous vaginal delivery decreased with the duration of pushing. We suggest active physiological evaluation of the labor progress together with continuous electronic fetal monitoring during pushing irrespective of guideline thresholds.

  19. Push technology at Argonne National Laboratory.

    Energy Technology Data Exchange (ETDEWEB)

    Noel, R. E.; Woell, Y. N.

    1999-04-06

    Selective dissemination of information (SDI) services, also referred to as current awareness searches, are usually provided by periodically running computer programs (personal profiles) against a cumulative database or databases. This concept of pushing relevant content to users has long been integral to librarianship. Librarians traditionally turned to information companies to implement these searches for their users in business, academia, and the science community. This paper describes how a push technology was implemented on a large scale for scientists and engineers at Argonne National Laboratory, explains some of the challenges to designers/maintainers, and identifies the positive effects that SDI seems to be having on users. Argonne purchases the Institute for Scientific Information (ISI) Current Contents data (all subject areas except Humanities), and scientists no longer need to turn to outside companies for reliable SDI service. Argonne's database and its customized services are known as ACCESS (Argonne-University of Chicago Current Contents Electronic Search Service).

  20. Directional preference in dogs: Laterality and "pull of the north".

    Science.gov (United States)

    Adámková, Jana; Svoboda, Jan; Benediktová, Kateřina; Martini, Sabine; Nováková, Petra; Tůma, David; Kučerová, Michaela; Divišová, Michaela; Begall, Sabine; Hart, Vlastimil; Burda, Hynek

    2017-01-01

    Laterality is a well described phenomenon in domestic dogs. It was shown that dogs, under calm Earth's magnetic field conditions, when marking their home ranges, tend to head about north- or southwards and display thus magnetic alignment. The question arises whether magnetic alignment might be affected or even compromised by laterality and vice versa. We tested the preference of dogs to choose between two dishes with snacks that were placed left and right, in different compass directions (north and east, east and south, south and west or west and north) in front of them. Some dogs were right-lateral, some left-lateral but most of them were ambilateral. There was a preference for the dish placed north compared to the one placed east of the dog ("pull of the north"). This effect was highly significant in small and medium-sized breeds but not in larger breeds, highly significant in females, in older dogs, in lateralized dogs but less significant or not significant in males, younger dogs, or ambilateral dogs. Laterality and "pull of the north" are phenomena which should be considered in diverse tasks and behavioral tests with which dogs or other animals might be confronted. The interaction and possible conflict between lateralization and "pull of the north" might be also considered as a reason for shifted magnetic alignment observed in different animal species in different contexts.

  1. Directional preference in dogs: Laterality and "pull of the north"

    Science.gov (United States)

    Adámková, Jana; Svoboda, Jan; Benediktová, Kateřina; Martini, Sabine; Nováková, Petra; Tůma, David; Kučerová, Michaela; Divišová, Michaela; Begall, Sabine; Hart, Vlastimil

    2017-01-01

    Laterality is a well described phenomenon in domestic dogs. It was shown that dogs, under calm Earth's magnetic field conditions, when marking their home ranges, tend to head about north- or southwards and display thus magnetic alignment. The question arises whether magnetic alignment might be affected or even compromised by laterality and vice versa. We tested the preference of dogs to choose between two dishes with snacks that were placed left and right, in different compass directions (north and east, east and south, south and west or west and north) in front of them. Some dogs were right-lateral, some left-lateral but most of them were ambilateral. There was a preference for the dish placed north compared to the one placed east of the dog ("pull of the north"). This effect was highly significant in small and medium-sized breeds but not in larger breeds, highly significant in females, in older dogs, in lateralized dogs but less significant or not significant in males, younger dogs, or ambilateral dogs. Laterality and “pull of the north” are phenomena which should be considered in diverse tasks and behavioral tests with which dogs or other animals might be confronted. The interaction and possible conflict between lateralization and "pull of the north" might be also considered as a reason for shifted magnetic alignment observed in different animal species in different contexts. PMID:28945773

  2. The push factors of intra-urban residential mobility in Calabar, Nigeria

    African Journals Online (AJOL)

    The paper takes a critical look at the push factors of intra-urban residential mobility in Calabar. Push factors are defined as those which operate to induce or encourage households to change their residence in the city. The paper notes that changing of residence by urban households in Western cities is a common ...

  3. Pushing the Limit: A Class Project

    Science.gov (United States)

    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…

  4. Introduction to nuclear supply chain management. In the context of fuel cycle strategy from LWR cycle system to FR cycle system

    International Nuclear Information System (INIS)

    Shiotani, Hiroki; Ono, Kiyoshi; Namba, Takashi; Yasumatsu, Naoto; Heta, Masanori

    2011-01-01

    Supply chain management (SCM) is an important technique to maintain supply and demand balance and to achieve total optimization from upstream to downstream in manufacturers' management. One of the major reasons why SCM receives much attention recently is the trend in production and sales systems from 'Push type' to 'Pull type'. 'Push type' can be restated as 'Make to Stock' (MTS). MTS is a type of supply chain in which the production is not connected to actual demand. On the contrary, 'Pull type' can be restated as 'Make to Order' (MTO) in which the production is connected to actual demand. In this paper, the terminologies and ideas of SCM was introduced into the scenario study to give a fresh perspective for considering LWR cycle to FR cycle transition strategies in Japan. Then, an analytical tool (SCM tool) which has been developed by the authors is used to survey Japanese nuclear energy system in transition with the SCM terminologies and viewpoints. When some of the Japanese nuclear fuel cycle strategies and tools are thought back with the framework of SCM, they tend to treat nuclear fuel cycle system as 'Push type' supply chain in their simulations. For example, a reprocessing plant separates SFs (spent fuels) without considering the actual Pu demand. However, because future reprocessing plants and fuel fabrication plants will act as Pu suppliers (front-end facility) to FR as well as back-end facilities of LWRs, the reasonable plant operation principle can be 'Pull type'. The analysis was conducted by the SCM tool to simulate the behaviors of both MTS and MTO type facilities during the LWR to FR transition period. If there are large uncertainties in the Pu demand or the load factor, etc. of future reprocessing plants, SCM framework is beneficial. Furthermore, the realization of MTO type operation by SCM can reduce the recovered Pu stock in spite of the increase of the SF interim storage. As the result of the investigation on the boundary location of 'Push type

  5. Do maternal pushing techniques during labour affect obstetric or neonatal outcomes?

    Science.gov (United States)

    Barasinski, C; Lemery, D; Vendittelli, F

    2016-10-01

    To assess, through a literature review, the maternal and neonatal morbidity associated with the type of pushing used during the second stage of labour. We searched the Cochrane Library and the Medline database for randomised controlled trials from 1980 to 2015, using the following keywords: "delivery", "birth", "birthing", "bearing down, coached, uncoached, pushing", "second and stage and labour", "randomised controlled trials" and "meta-analysis". Seven randomised controlled trials were found. Interventions varied between the studies. In the intervention groups, open-glottis pushing was spontaneous or coached. The groups did not differ for perineal injuries, episiotomies or type of birth. Impact on pelvic floor structure varied between the studies. Only one study found a better 5-minute Apgar score and a better umbilical artery pH in the "open glottis" group. The low methodological quality of the studies and the differences between the protocols do not justify a recommendation of a particular pushing technique. Further studies appear necessary to study outcomes with each of these techniques. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Accuracy of clinical observations of push-off during gait after stroke.

    Science.gov (United States)

    McGinley, Jennifer L; Morris, Meg E; Greenwood, Ken M; Goldie, Patricia A; Olney, Sandra J

    2006-06-01

    To determine the accuracy (criterion-related validity) of real-time clinical observations of push-off in gait after stroke. Criterion-related validity study of gait observations. Rehabilitation hospital in Australia. Eleven participants with stroke and 8 treating physical therapists. Not applicable. Pearson product-moment correlation between physical therapists' observations of push-off during gait and criterion measures of peak ankle power generation from a 3-dimensional motion analysis system. A high correlation was obtained between the observational ratings and the measurements of peak ankle power generation (Pearson r =.98). The standard error of estimation of ankle power generation was .32W/kg. Physical therapists can make accurate real-time clinical observations of push-off during gait following stroke.

  7. EFFICACY OF ADDUCTOR PULL BACK EXERCISE ON PAIN AND FUNCTIONAL DISABILITY FOR SACROILIAC JOINT DYSFUNCTION

    Directory of Open Access Journals (Sweden)

    Sai Kumar .N

    2015-08-01

    Full Text Available Background: Sacroiliac joint dysfunction (SIJD is a common problem that causes pain and disability. Adductor pull back exercise is widely used for treating sacroiliac joint dysfunction. No yet research has been directly examined the efficacy of adductor pull back exercise for sacroiliac joint dysfunction. The purpose of the study to find the efficacy of adductor pull back exercise on pain and functional disability for subjects with sacroiliac joint dysfunction. Methods: An experimental study design, 40 subjects with unilateral Sacroiliac joint dysfunction were randomized into two groups: study group (n=20, and control group (n=20. Subjects in study group received adductor pull back exercise along with conventional exercise and Subjects in control group received conventional exercise. The duration of treatment was given for two weeks, three times a day, total six days per week. Outcome measures such as pain was measured using Visual analog scale (VAS, and functional disability was measured using Oswestry Disability Index questionnaire (ODI before and after 2 weeks of the treatment in both the groups. Results: When means were analyzed using Independent ‘t’ test as a parametric and Mann Whitney U test as a non-parametric test, there is a statistically significant improvements in means of VAS, and ODI within the groups. When means were compared using Independent ‘t’ and Mann Whitney U test, there is a significant difference in post-means of VAS and ODI between the groups. Conclusion: The present study concludes that the 2 weeks of adductor pull back exercise along with conventional exercise found statistically and clinically significant effect on improving pain, functional disability for subjects with sacroiliac joint dysfunction. Adductors pull back exercise along with conventional exercise techniques shown to have greater percentage of improvement in improving pain and functional disability for subjects with sacroiliac joint dysfunction.

  8. Information Foraging in Nuclear Power Plant Control Rooms

    International Nuclear Information System (INIS)

    Boring, R.L.

    2011-01-01

    nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

  9. Information Foraging in Nuclear Power Plant Control Rooms

    Energy Technology Data Exchange (ETDEWEB)

    R.L. Boring

    2011-09-01

    nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

  10. The Pull Model as the E-Commerce Strategy For Business-To-Consumer Sites

    OpenAIRE

    Guillermo Reyes González; Ralf Eder Lange

    2013-01-01

    One of the solutions to stabilize the bullwhip effect is to provide the supply chain with the adequate mechanisms to make the information flow upstream (to the supplier) and downstream (to the consumer). This has led the e-commerce companies to implement a distribution model known as the Pull Model. This paper provides a literature review of the main characteristics of the Pull model and a comparison with the E-Commerce strategies and benefitsJournal: Revista de Administración, Finanzas y Eco...

  11. Building Capacity for Evidence-Based Public Health: Reconciling the Pulls of Practice and the Push of Research.

    Science.gov (United States)

    Brownson, Ross C; Fielding, Jonathan E; Green, Lawrence W

    2018-04-01

    Timely implementation of principles of evidence-based public health (EBPH) is critical for bridging the gap between discovery of new knowledge and its application. Public health organizations need sufficient capacity (the availability of resources, structures, and workforce to plan, deliver, and evaluate the preventive dose of an evidence-based intervention) to move science to practice. We review principles of EBPH, the importance of capacity building to advance evidence-based approaches, promising approaches for capacity building, and future areas for research and practice. Although there is general agreement among practitioners and scientists on the importance of EBPH, there is less clarity on the definition of evidence, how to find it, and how, when, and where to use it. Capacity for EBPH is needed among both individuals and organizations. Capacity can be strengthened via training, use of tools, technical assistance, assessment and feedback, peer networking, and incentives. Modest investments in EBPH capacity building will foster more effective public health practice.

  12. Engineered microbes and methods for microbial oil production

    Energy Technology Data Exchange (ETDEWEB)

    Stephanopoulos, Gregory; Tai, Mitchell; Chakraborty, Sagar

    2018-01-09

    Some aspects of this invention provide engineered microbes for oil production. Methods for microbe engineering and for use of engineered microbes are also provided herein. In some embodiments, microbes are provided that are engineered to modulate a combination of rate-controlling steps of lipid synthesis, for example, a combination of a step generating metabolites, acetyl-CoA, ATP or NADPH for lipid synthesis (a push step), and a step sequestering a product or an intermediate of a lipid synthesis pathway that mediates feedback inhibition of lipid synthesis (a pull step). Such push-and-pull engineered microbes exhibit greatly enhanced conversion yields and TAG synthesis and storage properties.

  13. Engineered microbes and methods for microbial oil production

    Science.gov (United States)

    Stephanopoulos, Gregory; Tai, Mitchell; Chakraborty, Sagar

    2015-02-10

    Some aspects of this invention provide engineered microbes for oil production. Methods for microbe engineering and for use of engineered microbes are also provided herein. In some embodiments, microbes are provided that are engineered to modulate a combination of rate-controlling steps of lipid synthesis, for example, a combination of a step generating metabolites, acetyl-CoA, ATP or NADPH for lipid synthesis (a push step), and a step sequestering a product or an intermediate of a lipid synthesis pathway that mediates feedback inhibition of lipid synthesis (a pull step). Such push-and-pull engineered microbes exhibit greatly enhanced conversion yields and TAG synthesis and storage properties.

  14. Selectively Encrypted Pull-Up Based Watermarking of Biometric data

    Science.gov (United States)

    Shinde, S. A.; Patel, Kushal S.

    2012-10-01

    Biometric authentication systems are becoming increasingly popular due to their potential usage in information security. However, digital biometric data (e.g. thumb impression) are themselves vulnerable to security attacks. There are various methods are available to secure biometric data. In biometric watermarking the data are embedded in an image container and are only retrieved if the secrete key is available. This container image is encrypted to have more security against the attack. As wireless devices are equipped with battery as their power supply, they have limited computational capabilities; therefore to reduce energy consumption we use the method of selective encryption of container image. The bit pull-up-based biometric watermarking scheme is based on amplitude modulation and bit priority which reduces the retrieval error rate to great extent. By using selective Encryption mechanism we expect more efficiency in time at the time of encryption as well as decryption. Significant reduction in error rate is expected to be achieved by the bit pull-up method.

  15. Interfacial push-out measurements of fully-bonded SiC/SiC composites

    International Nuclear Information System (INIS)

    Snead, L.L.; Steiner, D.; Zinkle, S.J.

    1990-01-01

    The direct measurement of interfacial bond strength and frictional resistance to sliding in a fully-bonded SiC/SiC composite is measured. It is shown that a fiber push-out technique can be utilized for small diameter fibers and very thin composite sections. Results are presented for a 22 micron thick section for which 37 out of 44 Nicalon fibers tested were pushed-out within the maximum nanoindentor load of 120 mN. Fiber interfacial yielding, push-out and sliding resistance were measured for each fiber. The distribution of interfacial strengths is treated as being Weibull in form. 14 refs., 5 figs

  16. The impact of pushed output on accuracy and fluency of Iranian EFL learners’ speaking

    Directory of Open Access Journals (Sweden)

    Aram Reza Sadeghi Beniss

    2014-07-01

    Full Text Available The current study attempted to establish baseline quantitative data on the impacts of pushed output on two components of speaking (i.e., accuracy and fluency. To achieve this purpose, 30 female EFL learners were selected from a whole population pool of 50 based on the standard test of IELTS interview and were randomly assigned into an experimental group and a control group. The participants in the experimental group received pushed output treatment while the students in the control group received non-pushed output instruction. The data were collected through IELTS interview and then the interview of each participant was separately tape-recorded and later transcribed and coded to measure accuracy and fluency. Then, the independent samples t-test was employed to analyze the collected data. The results revealed that the experimental group outperformed the control group in accuracy. In contrast, findings substantiated that pushed output had no impact on fluency. The positive impact of pushed output demonstrated in this study is consistent with the hypothesized function of Swain’s (1985 pushed output. The results can provide some useful insights into syllabus design and English language teaching.

  17. Pushing hard on the accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-09-15

    The quest for new techniques to drive future generations of particle accelerators has been pushed hard in recent years, efforts having been highlighted by workshops in Europe, organized by the European Committee for Future Accelerators, and in the US. The latest ECFA Workshop on New Developments in Particle Acceleration Techniques, held at Orsay from 29 June to 4 July, showed how the initial frantic search for innovation is now maturing.

  18. The effect of klapskate hinge position on push-off performance: a simulation study

    OpenAIRE

    Houdijk, J.H.P.; Bobbert, M.F.; de Koning, J.J.; de Groot, G.

    2003-01-01

    Purpose: The introduction of the klapskate in speed skating confronts skaters with the question of how to adjust the position of the hinge in order to maximize performance. The purpose of this study was to reveal the constraint that klapskate hinge position imposes on push-off performance in speed skating. Method: For this purpose, a model of the musculoskeletal system was designed to simulate a simplified, two-dimensional skating push off. To capture the essence of a skating push off, this m...

  19. Those who pull a rose of sharon off

    International Nuclear Information System (INIS)

    Lee, Byeong Yeong

    2011-06-01

    The contents of this book are going over the U. S. policy on nuclear issue, to bloom a rose of sharon, people who pull a rose of sharon off discharge out of appointment and participation into administration and trial on election law, over the farm hardship period, the story about development of nuclear energy. The report and the contract and the related articles.

  20. Octopus movement: push right, go left.

    Science.gov (United States)

    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.