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Sample records for force generation examined

  1. Force generation examined by laser temperature-jumps in shortening and lengthening mammalian (rabbit psoas) muscle fibres.

    Science.gov (United States)

    Ranatunga, K W; Coupland, M E; Pinniger, G J; Roots, H; Offer, G W

    2007-11-15

    We examined the tension change induced by a rapid temperature jump (T-jump) in shortening and lengthening active muscle fibres. Experiments were done on segments of permeabilized single fibres (length (L0) approximately 2 mm, sarcomere length 2.5 microm) from rabbit psoas muscle; [MgATP] was 4.6 mm, pH 7.1, ionic strength 200 mm and temperature approximately 9 degrees C. A fibre was maximally Ca2+-activated in the isometric state and a approximately 3 degrees C, rapid ( 0.05 L0 s(-1), whereas the tension decreased to about < 0.5 x P0 during shortening at 0.1-0.2 L0 s(-1); the unloaded shortening velocity was approximately 1 L0 s(-1) and the curvature of the force-shortening velocity relation was high (a/P0 ratio from Hill's equation of approximately 0.05). In isometric state, a T-jump induced a tension rise of 15-20% to a new steady state; by curve fitting, the tension rise could be resolved into a fast (phase 2b, 40-50 s(-1)) and a slow (phase 3, 5-10 s(-1)) exponential component (as previously reported). During steady lengthening, a T-jump induced a small instantaneous drop in tension, followed by recovery, so that the final tension recorded with and without a T-jump was not significantly different; thus, a T-jump did not lead to a net increase of tension. During steady shortening, the T-jump induced a pronounced tension rise and both its amplitude and the rate (from a single exponential fit) increased with shortening velocity; at 0.1-0.2 L0 s(-1), the extent of fibre shortening during the T-jump tension rise was estimated to be approximately 1.2% L(0) and it was shorter at lower velocities. At a given shortening velocity and over the temperature range of 8-30 degrees C, the rate of T-jump tension rise increased with warming (Q10 approximately 2.7), similar to phase 2b (endothermic force generation) in isometric muscle. Results are discussed in relation to the previous findings in isometric muscle fibres which showed that a T-jump promotes an early step in the

  2. Computer-Controlled Force Generator, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research, Inc. is developing a compact, low power, Next-Generation Exercise Device (NGRED) that can generate any force between 5 and 600 lbf. We use a closed...

  3. Computer-Controlled Force Generator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research, Inc. is developing a compact, low power, Next-Generation Exercise Device (NGRED) that can generate any force between 5 and 600 lbf. We use a closed...

  4. Force generation within tissues during development

    Science.gov (United States)

    Kasza, Karen

    During embryonic development, multicellular tissues physically change shape, move, and grow. Changes in epithelial tissue organization are often accomplished by local movements of cells that are driven largely by forces generated by the motor protein myosin II. These forces are patterned to orient cell movements, resulting in changes in tissue shape and organization to build functional tissues and organs. To investigate the mechanisms of force generation in vivo, we use the fruit fly embryo as a model system. Spatial patterns of forces orient cell movements to drive rapid tissue elongation along the head-to-tail axis of the embryo. I will describe how studying embryos generated with engineered myosin variants provides insight into where, when, and how forces are generated to efficiently reorganize tissues. We found that a myosin variant that is locked-in to the active or ``on'' state accelerates cell movements, while two mutant myosin variants associated with human disease produce slowed cell movement. These myosin variants all disrupt tissue elongation, but live imaging and biophysical measurements reveal distinct effects on myosin organization and dynamics within cells and uncover mechanisms that control the spatial and temporal patterns of force generation. These studies shed light not only on how defects in force generation contribute to disease but also on physical principles at work in active, living materials.

  5. Force generation by orthodontic coil springs.

    Science.gov (United States)

    von Fraunhofer, J A; Bonds, P W; Johnson, B E

    1993-01-01

    Nickel titanium (NiTi) coil springs are a new development in orthodontics, designed to produce light continuous forces. This study compares the force delivery by NiTi open and closed coil springs during unloading (de-activation) to that provided by comparable stainless steel (SS) springs. Open-coil springs (0.010 x 0.035 inch) were compressed from their initial length of 15 mm to 6 mm and the forces generated with spring recovery recorded. Closed-coil springs (0.009 x 0.035 inch) were distracted from their initial length of 3 mm to 9 mm and the force recorded as the spring recovered. The closed-coil NiTi springs produced light continuous forces of 75-90 g over the distraction range of 6 mm while the open-coil springs produced forces of 55-70 g within the 9 mm compression range. SS springs produced heavier forces, ca. 200 g, for an activation of 1 mm and the generated force increased rapidly as the activation was increased. The findings indicate that NiTi coil springs deliver optimal forces for orthodontic tooth movement over a longer activation range than comparable SS springs.

  6. FMNL formins boost lamellipodial force generation

    DEFF Research Database (Denmark)

    Kage, Frieda; Winterhoff, Moritz; Dimchev, Vanessa

    2017-01-01

    Migration frequently involves Rac-mediated protrusion of lamellipodia, formed by Arp2/3 complex-dependent branching thought to be crucial for force generation and stability of these networks. The formins FMNL2 and FMNL3 are Cdc42 effectors targeting to the lamellipodium tip and shown here...... reduces both migration and capability of cells to move against viscous media. Together, we conclude that force generation in lamellipodia strongly depends on FMNL formin activity, operating in addition to Arp2/3 complex-dependent filament branching....

  7. Forced circulation steam generators for SAGD applications

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, M [Engineered Boiler Systems (United States)

    2011-07-01

    Steam for steam assisted gravity drainage (SAGD) is traditionally supplied by once-through steam generators (OTSG) or drum type boilers. Research by Cleaver Brooks aims to combine the quality features of OTSGs and drum boilers and to address issues encountered with both these types of machinery. The forced-circulation oil sands steam generator (FC-OSSG) resulted from the design of a flow management system which allowed water quality upsets to be handled successfully. Integration of the boiler and the burner design through computational fluid dynamics (CFD) led to a decrease in the environmental footprint of the steam generator. Circuit maintenance was also significantly facilitated by elaborating new piggable circuits. Moreover, the design of a water cooled furnace enabled the generator to work at constant heat. The resulting FC-OSSG produces cleaner steam than either OTSGs or drum boilers, and has a higher capacity than OTSGs. Additionally, turndown, blowdown and feedwater quality are similar to that obtained using drum boilers.

  8. Steam generator of the forced circulation type

    International Nuclear Information System (INIS)

    Forestier, Jean; Leblanc, Bernard; Monteil, Marcel; Monteil, Pierre

    1977-01-01

    The steam generator described is of the forced circulation single passage type comprising an outer casing including a vertical generally cylindrical side ring, an internal skirt coaxial with the outer casing, the bottom of this skirt having a free edge separated from a bottom end closing the outer casing, a central tube plate extending horizontally near a top end, in opposition to the bottom end, a peripheral tube plate, parallel to the central plate and located in the annular space under this central plate, a bundle of J shaped tubes [fr

  9. Curvature recognition and force generation in phagocytosis

    Directory of Open Access Journals (Sweden)

    Prassler Jana

    2010-12-01

    Full Text Available Abstract Background The uptake of particles by actin-powered invagination of the plasma membrane is common to protozoa and to phagocytes involved in the immune response of higher organisms. The question addressed here is how a phagocyte may use geometric cues to optimize force generation for the uptake of a particle. We survey mechanisms that enable a phagocyte to remodel actin organization in response to particles of complex shape. Results Using particles that consist of two lobes separated by a neck, we found that Dictyostelium cells transmit signals concerning the curvature of a surface to the actin system underlying the plasma membrane. Force applied to a concave region can divide a particle in two, allowing engulfment of the portion first encountered. The phagosome membrane that is bent around the concave region is marked by a protein containing an inverse Bin-Amphiphysin-Rvs (I-BAR domain in combination with an Src homology (SH3 domain, similar to mammalian insulin receptor tyrosine kinase substrate p53. Regulatory proteins enable the phagocyte to switch activities within seconds in response to particle shape. Ras, an inducer of actin polymerization, is activated along the cup surface. Coronin, which limits the lifetime of actin structures, is reversibly recruited to the cup, reflecting a program of actin depolymerization. The various forms of myosin-I are candidate motor proteins for force generation in particle uptake, whereas myosin-II is engaged only in retracting a phagocytic cup after a switch to particle release. Thus, the constriction of a phagocytic cup differs from the contraction of a cleavage furrow in mitosis. Conclusions Phagocytes scan a particle surface for convex and concave regions. By modulating the spatiotemporal pattern of actin organization, they are capable of switching between different modes of interaction with a particle, either arresting at a concave region and applying force in an attempt to sever the particle

  10. Interrater reliability of quantitative ultrasound using force feedback among examiners with varied levels of experience

    Directory of Open Access Journals (Sweden)

    Michael O. Harris-Love

    2016-06-01

    Full Text Available Background. Quantitative ultrasound measures are influenced by multiple external factors including examiner scanning force. Force feedback may foster the acquisition of reliable morphometry measures under a variety of scanning conditions. The purpose of this study was to determine the reliability of force-feedback image acquisition and morphometry over a range of examiner-generated forces using a muscle tissue-mimicking ultrasound phantom. Methods. Sixty material thickness measures were acquired from a muscle tissue mimicking phantom using B-mode ultrasound scanning by six examiners with varied experience levels (i.e., experienced, intermediate, and novice. Estimates of interrater reliability and measurement error with force feedback scanning were determined for the examiners. In addition, criterion-based reliability was determined using material deformation values across a range of examiner scanning forces (1–10 Newtons via automated and manually acquired image capture methods using force feedback. Results. All examiners demonstrated acceptable interrater reliability (intraclass correlation coefficient, ICC = .98, p .90, p < .001, independent of their level of experience. The measurement error among all examiners was 1.5%–2.9% across all applied stress conditions. Conclusion. Manual image capture with force feedback may aid the reliability of morphometry measures across a range of examiner scanning forces, and allow for consistent performance among examiners with differing levels of experience.

  11. Propulsive force symmetry generated during butterfly swimming

    Directory of Open Access Journals (Sweden)

    Gustavo Soares Pereira

    2015-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n6p704   The aim of the study was to analyze the hand force symmetry in butterfly swimming. Fourteen male and female swimmers (18.4 ± 4.9 years old, 71.8 ± 14.6 kg of body mass, 1.78 ± 0.09 m of height and mean performance that corresponds to 74.9 ± 5.8% of the world record. Subjects performed three trials of 25 m of butterfly swimming at maximal speed. Mean and maximum forces were estimated for each hand using pressure sensors of the Aquanex System (Swimming Technology Research, USA. The comparisons between force values for dominant and non-dominant hands were made through Student’s T test for dependent samples (p<0.05. In addition, the symmetry Index (SI was calculated as a relative measure of the force applied by each hand. The mean and maximum force for the dominant hand corresponded, respectively, to 55.7 ± 14.7 N and 114.7 ± 39.6 N. For the non-dominant hand, values were 51.2 ± 14.7 N for mean force and 110.7 ± 36.7 N for maximum force. Significant differences were found between dominant and non-dominant hands for both variables (p<0.01. The symmetry index analysis showed mean values of 8.9% for mean force and of 12.6% for maximum force, and most swimmers presented values higher than 10% for mean and/or maximum forces. Further studies should be performed in order to investigate the relationship between hand force symmetry and swimming performance.

  12. A novel three-filament model of force generation in eccentric contraction of skeletal muscles.

    Science.gov (United States)

    Schappacher-Tilp, Gudrun; Leonard, Timothy; Desch, Gertrud; Herzog, Walter

    2015-01-01

    We propose and examine a three filament model of skeletal muscle force generation, thereby extending classical cross-bridge models by involving titin-actin interaction upon active force production. In regions with optimal actin-myosin overlap, the model does not alter energy and force predictions of cross-bridge models for isometric contractions. However, in contrast to cross-bridge models, the three filament model accurately predicts history-dependent force generation in half sarcomeres for eccentric and concentric contractions, and predicts the activation-dependent forces for stretches beyond actin-myosin filament overlap.

  13. A novel three-filament model of force generation in eccentric contraction of skeletal muscles.

    Directory of Open Access Journals (Sweden)

    Gudrun Schappacher-Tilp

    Full Text Available We propose and examine a three filament model of skeletal muscle force generation, thereby extending classical cross-bridge models by involving titin-actin interaction upon active force production. In regions with optimal actin-myosin overlap, the model does not alter energy and force predictions of cross-bridge models for isometric contractions. However, in contrast to cross-bridge models, the three filament model accurately predicts history-dependent force generation in half sarcomeres for eccentric and concentric contractions, and predicts the activation-dependent forces for stretches beyond actin-myosin filament overlap.

  14. Cyclosporine increases muscular force generation in Duchenne muscular dystrophy.

    Science.gov (United States)

    Sharma, K R; Mynhier, M A; Miller, R G

    1993-03-01

    We investigated the effect of cyclosporine (CsA) on force generation in 15 boys with Duchenne muscular dystrophy (DMD) by obtaining monthly measures of tetanic force and maximum voluntary contraction (MVC) of both anterior tibial muscles. During 4 months of a natural history phase, both tetanic force and MVC declined significantly. During 8 weeks of CsA treatment (5 mg/kg/day), significantly increased tetanic force (25.8 +/- 6.6%) and MVC (13.6 +/- 4.0%) occurred within 2 weeks. The maximum mean increase during treatment was 35.2 +/- 5.9% (tetanic force) and 19.0 +/- 4.6% (MVC). Side effects from CsA, gastrointestinal and flu-like symptoms, were transient and self-limiting. Thus, as previously reported with prednisone, CsA increases muscular force generation in the anterior tibial muscles of DMD patients.

  15. Scaling of motor cortical excitability during unimanual force generation.

    Science.gov (United States)

    Perez, Monica A; Cohen, Leonardo G

    2009-10-01

    During performance of a unimanual force generation task primary motor cortices (M1s) experience clear functional changes. Here, we evaluated the way in which M1s interact during parametric increases in right wrist flexion force in healthy volunteers. We measured the amplitude and the slope of motor evoked potentials (MEP) recruitment curves to transcranial magnetic stimulation (TMS) in the left and right flexor carpi radialis (FCR) muscles at rest and during 10%, 30% and 70% of maximal wrist flexion force. At rest, no differences were observed in the amplitude and slope of MEP recruitment curves in the left and right FCR muscles. With increasing right wrist flexion force, MEP amplitudes increased in both FCR muscles, with larger amplitudes in the right FCR. We found a significant correlation between the left and right MEP amplitudes across conditions. The slope of right and left FCR MEP recruitment curve was significantly steeper at 70% of force compared to rest and 10% of force. A significant correlation between the slope of left and right FCR MEP amplitudes was found at 70% of force only. Our results indicate a differential scaling of excitability in the corticospinal system controlling right and left FCR muscles at increasing levels of unimanual force generation. Specifically, these data highlights that at strong levels of unimanual force the increases in motor cortical excitability with increasing TMS stimulus intensities follow a similar pattern in both M1s, while at low levels of force they do not.

  16. Dynamics of flagellar force generated by a hyperactivated spermatozoon.

    Science.gov (United States)

    Ishijima, Sumio

    2011-09-01

    The flagellar force generated by a hyperactivated monkey spermatozoon was evaluated using the resistive force theory applied to the activated (nonhyperactivated) and hyperactivated flagellar waves that were obtained using high-speed video microscopy and digital image processing in order to clarify the mechanism of sperm penetration through the zona pellucida. No difference in the maximum propulsive force, which was parallel to the longitudinal sperm head axis, was found between the activated and hyperactivated spermatozoa. The maximum transverse force (45 pN), which was perpendicular to the longitudinal sperm head axis, of the hyperactivated spermatozoon was ∼2.5 times its propulsive force. As the beat frequency of the flagellar beating remarkably decreased during the hyperactivation, the slowly oscillating transverse force (5 Hz) by the hyperactivated spermatozoon seems to be most effective for sperm penetration through the zona pellucida.

  17. Flapping motion and force generation in a viscoelastic fluid

    Science.gov (United States)

    Normand, Thibaud; Lauga, Eric

    2008-12-01

    In a variety of biological situations, swimming cells have to move through complex fluids. Similarly, mucociliary clearance involves the transport of polymeric fluids by beating cilia. Here, we consider the extent to which complex fluids could be exploited for force generation on small scales. We consider a prototypical reciprocal motion (i.e., identical under time-reversal symmetry): the periodic flapping of a tethered semi-infinite plane. In the Newtonian limit, such motion cannot be used for force generation according to Purcell’s scallop theorem. In a polymeric fluid (Oldroyd-B, and its generalization), we show that this is not the case and calculate explicitly the forces on the flapper for small-amplitude sinusoidal motion. Three setups are considered: a flapper near a wall, a flapper in a wedge, and a two-dimensional scalloplike flapper. In all cases, we show that at quadratic order in the oscillation amplitude, the tethered flapping motion induces net forces, but no average flow. Our results demonstrate therefore that the scallop theorem is not valid in polymeric fluids. The reciprocal component of the movement of biological appendages such as cilia can thus generate nontrivial forces in polymeric fluid such as mucus, and normal-stress differences can be exploited as a pure viscoelastic force generation and propulsion method.

  18. Atomic force microscopy for the examination of single cell rheology.

    Science.gov (United States)

    Okajima, Takaharu

    2012-11-01

    Rheological properties of living cells play important roles in regulating their various biological functions. Therefore, measuring cell rheology is crucial for not only elucidating the relationship between the cell mechanics and functions, but also mechanical diagnosis of single cells. Atomic force microscopy (AFM) is becoming a useful technique for single cell diagnosis because it allows us to measure the rheological properties of adherent cells at any region on the surface without any modifications. In this review, we summarize AFM techniques for examining single cell rheology in frequency and time domains. Recent applications of AFM for investigating the statistical analysis of single cell rheology in comparison to other micro-rheological techniques are reviewed, and we discuss what specificity and universality of cell rheology are extracted using AFM.

  19. Generation of spin motive force in a soliton lattice

    International Nuclear Information System (INIS)

    Ovchinnikov, A. S.; Sinitsyn, V. E.; Bostrem, I. G.; Kishine, J.

    2013-01-01

    The generation of a spin motive force in a chiral helimagnet due to the action of two crossed magnetic fields is considered. The cases of pulsed and periodic magnetic fields directed along the helical axis under a perpendicular dc field are analyzed. It is shown that, in the case of a pulsed field, the spin motive force is related to dissipation, whereas in a periodic field, there is a reactive component that is not related to damping processes.

  20. Examination of concept of next generation computer. Progress report 1999

    International Nuclear Information System (INIS)

    Higuchi, Kenji; Hasegawa, Yukihiro; Hirayama, Toshio

    2000-12-01

    The Center for Promotion of Computational Science and Engineering has conducted R and D works on the technology of parallel processing and has started the examination of the next generation computer in 1999. This report describes the behavior analyses of quantum calculation codes. It also describes the consideration for the analyses and examination results for the method to reduce cash misses. Furthermore, it describes a performance simulator that is being developed to quantitatively examine the concept of the next generation computer. (author)

  1. Physical Modeling of microtubule force generation and self-organization

    NARCIS (Netherlands)

    Tanase, C.

    2004-01-01

    Biological systems are complex heterogeneous and far from equilibrium systems. The fundamental questions posed by the physics of such systems are what the force generation mechanisms are, and how energy is processed and distributed among the components inside them. In answering these questions we

  2. Crouched Posture Maximizes Ground Reaction Forces Generated by Muscles

    Science.gov (United States)

    Hoang, Hoa X.; Reinbolt, Jeffrey A.

    2012-01-01

    Crouch gait decreases walking efficiency due to the increased knee and hip flexion during the stance phase of gait. Crouch gait is generally considered to be disadvantageous for children with cerebral palsy; however, a crouched posture may allow biomechanical advantages that lead some children to adopt a crouch gait. To investigate one possible advantage of crouch gait, a musculoskeletal model created in OpenSim was placed in 15 different postures from upright to severe crouch during initial, middle, and final stance of the gait cycle for a total of 45 different postures. A series of optimizations was performed for each posture to maximize transverse plane ground reaction forces in the 8 compass directions by modifying muscle forces acting on the model. We compared the force profile areas across all postures. Larger force profile areas were allowed by postures from mild crouch (for initial stance) to crouch (for final stance). The overall ability to generate larger ground reaction force profiles represents a mechanical advantage of a crouched posture. This increase in muscle capacity while in a crouched posture may allow a patient to generate new movements to compensate for impairments associated with cerebral palsy, such as motor control deficits. PMID:22542242

  3. Destructive examination and analyses of pulled steam generator tubes

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Kim, H. P.; Kim, J. S.; Lim, Y. S.; Hwang, S. S.; Kim, S. W.; Jeong, M. K.; Hong, J. H.; Kim, W. W.

    2011-07-01

    Steam generator model F in Kori 3, Younggwang 2 and Younggwang 1 as 950MWe PWR was provided by Westinghouse. Steam generator tube made of Alloy 600TT material (outer diameter 0.688'(17.475 mm), thickness 0.04'(1.016mm) in Blairsville was provided by Huntington alloys. Steam generator in Ulchin 4 as 1000MWe KHNP PWR was manufactured by Doosan heavy industry and steam generator tubes were manufactured by B and W (Bobcock and Wilcox). Alloy 600 MA was used as steam generator tubing material of outer diameter 19.05mm and thickness 1.07mm. Five tubes of Alloy 600TT which showed crack signal from non-destructive examination were pulled from Kori 3, Younggwang 2 and Younggwang 1. Two tubes which showed crack signal from non-destructive examination were pulled from Ulchin 4. For the pulled tubes, KAERI performed destructive examination. Through the destructive examination, the existence of cracks were confirmed and the cause of crack was investigated. Remedy was also suggested to mitigate the present circumstances. Stress corrosion cracking (SCC) was observed for Alloy 600TT tubes. It was recommended that the sludge content should be lowered, deleterious elements and MRI should be maintained continuously. For Ulchin 4, SCC was confirmed for Alloy 600MA tubes. It is necessary to lower and remove the sludge in the near term. In the longer term, replacement of steam generator was suggested

  4. An examination of the variables that affect express saccade generation.

    Science.gov (United States)

    Schiller, Peter H; Haushofer, Johannes; Kendall, Geoffery

    2004-01-01

    The frequency with which express saccades are generated under a variety of conditions in rhesus monkeys was examined. Increasing the gap time between fixation spot termination and target onset increased express saccade frequency but was progressively less effective in doing so as the number of target positions in the sample was increased. Express saccades were rarely produced when two targets were presented simultaneously and the choice of either of which was rewarded; a temporal asynchrony of only 17 ms between the targets reinstated express saccade generation. Express saccades continued to be generated when the vergence or pursuit systems was coactivated with the saccadic system.

  5. Does dynamic stability govern propulsive force generation in human walking?

    Science.gov (United States)

    Browne, Michael G; Franz, Jason R

    2017-11-01

    Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking speed and propulsive force ( F P ) generation on dynamic stability in young adults, and (ii) the extent to which young adults prioritize dynamic stability in selecting their preferred combination of walking speed and F P generation. Subjects walked on a force-measuring treadmill across a range of speeds as well as at constant speeds while modulating their F P according to a visual biofeedback paradigm based on real-time force measurements. In contrast to improvements when walking slower, walking with a diminished push-off worsened dynamic stability by up to 32%. Rather, we find that young adults adopt an F P at their preferred walking speed that maximizes dynamic stability. One implication of these findings is that the onset of a diminished push-off in old age may independently contribute to poorer balance control and precipitate slower walking speeds.

  6. Morphological Transformation and Force Generation of Active Cytoskeletal Networks.

    Directory of Open Access Journals (Sweden)

    Tamara Carla Bidone

    2017-01-01

    Full Text Available Cells assemble numerous types of actomyosin bundles that generate contractile forces for biological processes, such as cytokinesis and cell migration. One example of contractile bundles is a transverse arc that forms via actomyosin-driven condensation of actin filaments in the lamellipodia of migrating cells and exerts significant forces on the surrounding environments. Structural reorganization of a network into a bundle facilitated by actomyosin contractility is a physiologically relevant and biophysically interesting process. Nevertheless, it remains elusive how actin filaments are reoriented, buckled, and bundled as well as undergo tension buildup during the structural reorganization. In this study, using an agent-based computational model, we demonstrated how the interplay between the density of myosin motors and cross-linking proteins and the rigidity, initial orientation, and turnover of actin filaments regulates the morphological transformation of a cross-linked actomyosin network into a bundle and the buildup of tension occurring during the transformation.

  7. System for Automatic Generation of Examination Papers in Discrete Mathematics

    Science.gov (United States)

    Fridenfalk, Mikael

    2013-01-01

    A system was developed for automatic generation of problems and solutions for examinations in a university distance course in discrete mathematics and tested in a pilot experiment involving 200 students. Considering the success of such systems in the past, particularly including automatic assessment, it should not take long before such systems are…

  8. Force

    CERN Document Server

    Graybill, George

    2007-01-01

    Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

  9. Planning for and Applying Military Force: An Examination of Terms

    National Research Council Canada - National Science Library

    Van Riper, Paul K

    2006-01-01

    This Letort Paper briefly examines current and, in some cases, still evolving definitions in joint doctrine -- especially with regard to strategy, center of gravity, decisive point, and commander's intent...

  10. Job-specific mandatory medical examinations for the police force

    NARCIS (Netherlands)

    Boschman, J. S.; Hulshof, C. T. J.; Frings-Dresen, M. H. W.; Sluiter, J. K.

    2017-01-01

    Background Mandatory medical examinations (MMEs) of workers should be based on the health and safety requirements that are needed for effectively performing the relevant work. For police personnel in the Netherlands, no job-specific MME exists that takes the specific tasks and duties into account.

  11. Slurry steam generator program and baseline eddy current examination

    International Nuclear Information System (INIS)

    Clark, R.A.; Doctor, P.G.

    1985-01-01

    The Steam Generator Group Project was initiated in January 1982 with formation of consortium including NRC, EPRI, Japanese, French, and Italian participants. The project utilizes a retired-from-service nuclear steam generator established in a specially designed facility which houses the unit in its normal vertical operating position. The most important objectives deal with validation of nondestructive examination (NDE) techniques used to characterize steam generators during service. This research generator offers the first opportunity to characterize a statistically significant number of service-induced defects nondestructively followed by destructive metallographic confirmation. The project seeks to establish the reliability of defect detection and the accuracy of sizing defects via current state-of-the-art NDE. Other service degraded tubes will be burst tested to establish remaining service integrity. The integrity information and NDE reliability results will serve as inputs to establish a model for steam generator in-service inspections, and provide a data base for evaluation of tube plugging criteria. In addition to NDE validation goals, the project will use the service degraded generator as a specimen for demonstration/proof testing of repair and maintenance techniques, including chemical cleaning/decontamination technologies. In addition to the efforts associated with NDE, a multitude of other project tasks have continued through 1984, and results are presented

  12. Probing cooperative force generation in collective cancer invasion

    Science.gov (United States)

    Alobaidi, Amani A.; Xu, Yaopengxiao; Chen, Shaohua; Jiao, Yang; Sun, Bo

    2017-08-01

    Collective cellular dynamics in the three-dimensional extracellular matrix (ECM) plays a crucial role in many physiological processes such as cancer invasion. Both chemical and mechanical signaling support cell-cell communications on a variety of length scales, leading to collective migratory behaviors. Here we conduct experiments using 3D in vitro tumor models and develop a phenomenological model in order to probe the cooperativity of force generation in the collective invasion of breast cancer cells. In our model, cell-cell communication is characterized by a single parameter that quantifies the correlation length of cellular migration cycles. We devise a stochastic reconstruction method to generate realizations of cell colonies with specific contraction phase correlation functions and correlation length a. We find that as a increases, the characteristic size of regions containing cells with similar contraction phases grows. For small a values, the large fluctuations in individual cell contraction phases smooth out the temporal fluctuations in the time-dependent deformation field in the ECM. For large a values, the periodicity of an individual cell contraction cycle is clearly manifested in the temporal variation of the overall deformation field in the ECM. Through quantitative comparisons of the simulated and experimentally measured deformation fields, we find that the correlation length for collective force generation in the breast cancer diskoid in geometrically micropatterned ECM (DIGME) system is a≈ 25~μ \\text{m} , which is roughly twice the linear size of a single cell. One possible mechanism for this intermediate cell correlation length is the fiber-mediated stress propagation in the 3D ECM network in the DIGME system.

  13. Generation of intermittent gravitocapillary waves via parametric forcing

    Science.gov (United States)

    Castillo, Gustavo; Falcón, Claudio

    2018-04-01

    We report on the generation of an intermittent wave field driven by a horizontally moving wave maker interacting with Faraday waves. The spectrum of the local gravitocapillary surface wave fluctuations displays a power law in frequency for a wide range of forcing parameters. We compute the probability density function of the local surface height increments, which show that they change strongly across time scales. The structure functions of these increments are shown to display power laws as a function of the time lag, with exponents that are nonlinear functions of the order of the structure function. We argue that the origin of this scale-invariant intermittent spectrum is the Faraday wave pattern breakup due to its advection by the propagating gravity waves. Finally, some interpretations are proposed to explain the appearance of this intermittent spectrum.

  14. Job-specific mandatory medical examinations for the police force.

    Science.gov (United States)

    Boschman, J S; Hulshof, C T J; Frings-Dresen, M H W; Sluiter, J K

    2017-08-01

    Mandatory medical examinations (MMEs) of workers should be based on the health and safety requirements that are needed for effectively performing the relevant work. For police personnel in the Netherlands, no job-specific MME exists that takes the specific tasks and duties into account. To provide the Dutch National Police with a knowledge base for job-specific MMEs for police personnel that will lead to equitable decisions from an occupational health perspective about who can perform police duties. We used a stepwise mixed-methods approach in which we included interviews with employees and experts and a review of the national and international literature. We determined the job demands for the various police jobs, determined which were regarded as specific job demands and formulated the matching health requirements as specific as possible for each occupation. A total of 21 specific job demands were considered relevant in different police jobs. These included biomechanical, physiological, physical, emotional, psychological/cognitive and sensory job demands. We formulated both police-generic and job-specific health requirements based on the specific job demands. Two examples are presented: bike patrol and criminal investigation. Our study substantiated the need for job-specific MMEs for police personnel. We found specific job demands that differed substantially for various police jobs. The corresponding health requirements were partly police-generic, and partly job-specific. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  15. AF Security Forces and Building Partner Capacity Examining Cultural Competency as a Force Enabler

    Science.gov (United States)

    2017-02-03

    personal experiences as a Security Forces commander executing the Police Transition Team mission in Iraq. Ultimately this analysis revolves around... eyes of the indigenous culture, it wasn’t a war for communism, it was a civil war for unification. “Former Secretary of Defense Robert McNamara...in a color coded method for each of the police stations and police chiefs and then report that information up the chain of command in what was called

  16. The suitability of Sanders' model for calculation of the propulsive force generated by the hands during sculling motion.

    Science.gov (United States)

    Gomes, Lara Elena; Boeira, Lucas; Loss, Jefferson Fagundes

    2017-05-01

    This study examined whether Sanders' model is suitable for estimating accurately the propulsive force generated by the hands' motion in swimming comparing the calculated force obtained using the model and the measured force during an actual propulsive action. The measured and calculated forces were obtained from 13 swimmers who, while tethered, performed a sculling motion in a prone position for the purpose of displacing the body by moving it forward. Kinematic analyses were conducted to obtain the calculated force, while the measured force was obtained via the use of a load cell. The calculated force was lower than the measured force and accounted for only a small part of the variation in the measured force. The forces could not be used interchangeably, and there were fixed and proportional differences between them. Consequently, this study indicates that Sanders' model is not suitable for estimating accurately the propulsive force generated by the swimmer's hands during sculling motion. However, research that integrates analyses from different approaches could result in improvements to the model that would render it applicable for estimating the propulsive forces during movements that are characterised by directional changes of the hands.

  17. Preparing the Periphery for a Subsequent Behavior: Motor Neuronal Activity during Biting Generates Little Force but Prepares a Retractor Muscle to Generate Larger Forces during Swallowing in Aplysia

    Science.gov (United States)

    Lu, Hui; McManus, Jeffrey M.; Cullins, Miranda J.

    2015-01-01

    Some behaviors occur in obligatory sequence, such as reaching before grasping an object. Can the earlier behavior serve to prepare the musculature for the later behavior? If it does, what is the underlying neural mechanism of the preparation? To address this question, we examined two feeding behaviors in the marine mollusk Aplysia californica, one of which must precede the second: biting and swallowing. Biting is an attempt to grasp food. When that attempt is successful, the animal immediately switches to swallowing to ingest food. The main muscle responsible for pulling food into the buccal cavity during swallowing is the I3 muscle, whose motor neurons B6, B9, and B3 have been previously identified. By performing recordings from these neurons in vivo in intact, behaving animals or in vitro in a suspended buccal mass preparation, we demonstrated that the frequencies and durations of these motor neurons increased from biting to swallowing. Using the physiological patterns of activation to drive these neurons intracellularly, we further demonstrated that activating them using biting-like frequencies and durations, either alone or in combination, generated little or no force in the I3 muscle. When biting-like patterns preceded swallowing-like patterns, however, the forces during the subsequent swallowing-like patterns were significantly enhanced. Sequences of swallowing-like patterns, either with these neurons alone or in combination, further enhanced forces in the I3 muscle. These results suggest a novel mechanism for enhancing force production in a muscle, and may be relevant to understanding motor control in vertebrates. PMID:25810534

  18. Two-phase forced-convective fouling under steam generator operating conditions

    International Nuclear Information System (INIS)

    Klimas, S.J.; Pietralik, J.M.

    2002-01-01

    Two-phase forced-convective fouling can occur in adiabatic two-phase flow and in diabatic two-phase flow, where it can be a significant contributor to fouling under flow-boiling conditions. For recirculating steam generators (SGs), it is, therefore, of significance to steam separators, tube support plates, tubesheet and the tube bundle. Loop test data are presented on forced-convective fouling rate of iron corrosion products under a range of conditions relevant to the secondary-side of recirculating SGs. The measurements were performed using a number of corrosion products (magnetite, hematite and lepidocrocite) under a range of water chemistry conditions, with several different amines. The measurements were limited to the straight-tube geometry. Comparable fouling data are given for flow-boiling conditions. A SG artefact was examined to corroborate the loop data. The rate constants for the forced-convective fouling measurements are compared with those for flow-boiling fouling. Their relative magnitudes can vary greatly, depending on the chemistry and thermohydraulic conditions. Boiling fouling dominated over forced-convection fouling for hematite and lepidocrocite particles, likely because of particle-bubble interactions. Forced-convective fouling rate was only slightly lower than boiling fouling for magnetite. For the region of cross-flow (upper tube bundle), deposits show significant thickness variation. Four or five deposit thickness peaks are noted, approximately equally spaced circumferentially. It is hypothesized that the fouling pattern is developed due to the cross-flow pattern present in the tube bundle. The possible interactions between the force-convective and nucleate-boiling fouling streams are briefly discussed. A method is presented for the superposition of the forced-convective and nucleate boiling fouling components. This method is based on the Chen heat transfer correlation. (author)

  19. Field measurement of basal forces generated by erosive debris flows

    Science.gov (United States)

    McCoy, S.W.; Tucker, G.E.; Kean, J.W.; Coe, J.A.

    2013-01-01

    It has been proposed that debris flows cut bedrock valleys in steeplands worldwide, but field measurements needed to constrain mechanistic models of this process remain sparse due to the difficulty of instrumenting natural flows. Here we present and analyze measurements made using an automated sensor network, erosion bolts, and a 15.24 cm by 15.24 cm force plate installed in the bedrock channel floor of a steep catchment. These measurements allow us to quantify the distribution of basal forces from natural debris‒flow events that incised bedrock. Over the 4 year monitoring period, 11 debris‒flow events scoured the bedrock channel floor. No clear water flows were observed. Measurements of erosion bolts at the beginning and end of the study indicated that the bedrock channel floor was lowered by 36 to 64 mm. The basal force during these erosive debris‒flow events had a large‒magnitude (up to 21 kN, which was approximately 50 times larger than the concurrent time‒averaged mean force), high‒frequency (greater than 1 Hz) fluctuating component. We interpret these fluctuations as flow particles impacting the bed. The resulting variability in force magnitude increased linearly with the time‒averaged mean basal force. Probability density functions of basal normal forces were consistent with a generalized Pareto distribution, rather than the exponential distribution that is commonly found in experimental and simulated monodispersed granular flows and which has a lower probability of large forces. When the bed sediment thickness covering the force plate was greater than ~ 20 times the median bed sediment grain size, no significant fluctuations about the time‒averaged mean force were measured, indicating that a thin layer of sediment (~ 5 cm in the monitored cases) can effectively shield the subjacent bed from erosive impacts. Coarse‒grained granular surges and water‒rich, intersurge flow had very similar basal force distributions despite

  20. Acoustic manipulation of active spherical carriers: Generation of negative radiation force

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, Majid, E-mail: majid_rajabi@iust.ac.ir; Mojahed, Alireza

    2016-09-15

    This paper examines theoretically a novel mechanism of generating negative (pulling) radiation force for acoustic manipulation of spherical carriers equipped with piezoelectric actuators in its inner surface. In this mechanism, the spherical particle is handled by common plane progressive monochromatic acoustic waves instead of zero-/higher- order Bessel beams or standing waves field. The handling strategy is based on applying a spatially uniform harmonic electrical voltage at the piezoelectric actuator with the same frequency of handling acoustic waves, in order to change the radiation force effect from repulsive (away from source) to attractive (toward source). This study may be considered as a start point for development of contact-free precise handling and entrapment technology of active carriers which are essential in many engineering and medicine applications.

  1. The role of the cytoskeleton in cellular force generation in 2D and 3D environments

    International Nuclear Information System (INIS)

    Kraning-Rush, Casey M; Carey, Shawn P; Califano, Joseph P; Smith, Brooke N; Reinhart-King, Cynthia A

    2011-01-01

    To adhere and migrate, cells generate forces through the cytoskeleton that are transmitted to the surrounding matrix. While cellular force generation has been studied on 2D substrates, less is known about cytoskeletal-mediated traction forces of cells embedded in more in vivo-like 3D matrices. Recent studies have revealed important differences between the cytoskeletal structure, adhesion, and migration of cells in 2D and 3D. Because the cytoskeleton mediates force, we sought to directly compare the role of the cytoskeleton in modulating cell force in 2D and 3D. MDA-MB-231 cells were treated with agents that perturbed actin, microtubules, or myosin, and analyzed for changes in cytoskeletal organization and force generation in both 2D and 3D. To quantify traction stresses in 2D, traction force microscopy was used; in 3D, force was assessed based on single cell-mediated collagen fibril reorganization imaged using confocal reflectance microscopy. Interestingly, even though previous studies have observed differences in cell behaviors like migration in 2D and 3D, our data indicate that forces generated on 2D substrates correlate with forces within 3D matrices. Disruption of actin, myosin or microtubules in either 2D or 3D microenvironments disrupts cell-generated force. These data suggest that despite differences in cytoskeletal organization in 2D and 3D, actin, microtubules and myosin contribute to contractility and matrix reorganization similarly in both microenvironments

  2. Prairie Island Nuclear Generating Plant steam generator owners group II: examination of 3 tubes removed from steam generator No. 12

    International Nuclear Information System (INIS)

    Kuchirka, P.; Madeyski, A.; Pearson, R.

    1986-01-01

    The No. 12 steam generator at Prairie Island Unit 1 has experienced some degradation of the hot leg tubes within the tube sheet region. The history of the degradation is given. A comparison of the rate of degradation of No. 12 steam generator with similar rates at Point Beach and Ginna is presen. The No. 11 steam generator has not experienced similar degradation. To investigate the cause and degree of degradation and to obtain correlation of field eddy current (EC) indications with actual conditions, the three hot leg tube segments were removed from the No. 12 steam generator for laboratory EC testing and destructive examination. Two of the tubes had field EC indications in the tube sheet region and one was apparently free of indications. The results of the testing and examinations are given. These tests showed that the lab EC correlated well with the destructive exam, but the field EC did not. The lab EC detected defects that are >35% thru wall, whereas the field EC detected defects that are >80%. The principle degradation was intergranular stress corrosion cracking in the tube sheet region with some uniform intergranular attack. The clean tube had randomly distributed IGA with a maximum depth of 15%. tube/tube sheet deposit chemical analysis does not support the existence of a caustic environment. The conclusions of this work are given

  3. Examination of forced unsteady separated flow fields on a rotating wind turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Huyer, S [Univ. of Colorado, Boulder, CO (US)

    1993-04-01

    The wind turbine industry faces many problems regarding the construction of efficient and predictable wind turbine machines. Steady state, two-dimensional wind tunnel data are generally used to predict aerodynamic loads on wind turbine blades. Preliminary experimental evidence indicates that some of the underlying fluid dynamic phenomena could be attributed to dynamic stall, or more specifically to generation of forced unsteady separated flow fields. A collaborative research effort between the University of Colorado and the National Renewable Energy Laboratory was conducted to systematically categorize the local and global effects of three- dimensional forced unsteady flow fields.

  4. Transient forces generated by projectiles on variable quality mouthguards monitored by instrumented impact testing

    NARCIS (Netherlands)

    Warnet, Laurent; Greasley, A.

    2001-01-01

    Objectives: (a) To determine the force-time trace that occurs when a spring mounted simulated upper jaw is impacted; (b) to examine if mouthguards of variable quality have significant influence on such force-time traces; (c) to attempt to relate physical events to the profile of the force-time

  5. Estimation of the forces generated by the thigh muscles for transtibial amputee gait.

    Science.gov (United States)

    Voinescu, M; Soares, D P; Natal Jorge, R M; Davidescu, A; Machado, L J

    2012-04-05

    The forces generated by the muscles with origin on the human femur play a major role in transtibial amputee gait, as they are the most effective of the means that the body can use for propulsion. By estimating the forces generated by the thigh muscles of transtibial amputees, and comparing them to the forces generated by the thigh muscles of normal subjects, it is possible to better estimate the energy output needed from prosthetic devices. The purpose of this paper is to obtain the forces generated by the thigh muscles of transtibial amputees and compare these with forces obtained from the same muscles in the case of normal subjects. Two transtibial amputees and four normal subjects similar in size to the amputees were investigated. Level ground walking was chosen as the movement to be studied, since it is a common activity that most amputees engage in. Inverse dynamics and a muscle recruitment algorithm (developed by AnyBody Technology(®)) were used for generating the muscle activation patterns and for computing the muscle forces. The muscle forces were estimated as two sums: one for all posterior muscles and one for the anterior muscles, based on the position of the muscles of the thigh relative to the frontal plane of the human body. The results showed that a significantly higher force is generated by the posterior muscles of the amputees during walking, leading to a general increase of the metabolic cost necessary for one step. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. In vitro frictional forces generated by three different ligation methods.

    Science.gov (United States)

    Gandini, Paola; Orsi, Linda; Bertoncini, Chiara; Massironi, Sarah; Franchi, Lorenzo

    2008-09-01

    To test the hypothesis that there is no difference between the frictional forces produced by a passive self-ligating bracket (SLB) in vitro and a conventional bracket (CB) used with two types of elastomeric ligatures. The brackets, wires and ligation methods used in vitro were a passive SLB and a CB used with two types of elastomeric ligatures (conventional elastomeric ligature [CEL] and unconventional elastomeric ligatures [UEL]). The bracket ligation systems were tested with two types of wires (0.014'' super elastic nickel titanium wire and 0.019'' x 0.025'' stainless steel wire). Resistance to sliding of the bracket/wire/ligature systems was measured with an experimental model mounted on the crosshead of an Instron testing machine with a 10 N load cell. Each sample was tested 10 consecutive times under a dry state. Frictional forces close to 0 g were recorded in all tests with SLB and in all tests with UEL on CB with both wire types. Resistance to sliding increased significantly (87-177 g) (P UELs may represent a valid alternative to passive SLBs for low-friction biomechanics.

  7. Effect of Elastase-induced Emphysema on the Force-generating Ability of the Diaphragm

    Science.gov (United States)

    Supinski, Gerald S.; Kelsen, Steven G.

    1982-01-01

    The effect of emphysema on the ability of the diaphragm to generate force was examined in costal diaphragm muscle strips from 10 Golden hamsters killed 18 mo after intratracheal injection of pancreatic elastase in a dose producing hyperinflation (mean total lung capacity [TLC] = 163% of control) and generalized panacinar emphysema. 13 saline-injected normal animals served as controls. The time course of isometric tension and the effect of alterations in muscle fiber and sarcomere length on the isometric tension (T) generated in response to tetanizing electrical stimuli (length-tension [L-T] relationship) were examined. Elastase administration caused an increase in diaphragm muscle thickness and reduction in the length of costal diaphragm muscle fibers measured in situ. Emphysema significantly increased the maximum tetanic tension as a result of hypertrophy. Maximal tension corrected for increases in muscle cross-sectional area (T/cm2), however, was the same in emphysematous (E) and control (C) animals. Emphysema also shifted the muscle fiber L-T curve of the diaphragm but not of a control muscle, the soleus, toward shorter lengths. In contrast to the effects of E on the diaphragm muscle fiber L-T curve, the sarcomere L-T curve was the same in E and C. Since the length at which tension was maximal correlated closely with sarcomere number (r = 0.94; P < 0.001) reduction in the number of sarcomeres in series in muscles from emphysematous animals appeared to explain the shift in the muscle fiber L-T curve. We conclude that in elastase-induced emphysema adaptive changes both in diaphragm cross-sectional area and sarcomere number augment the force-generating ability of the diaphragm. We speculate that changes in sarcomere number compensate for alterations in muscle fiber length resulting from chronic hyperinflation of the thorax, while diaphragmatic muscle hypertrophy represents a response to changes in respiratory load and/or diaphragm configuration (La

  8. Applying the cost of generating force hypothesis to uphill running

    Directory of Open Access Journals (Sweden)

    Wouter Hoogkamer

    2014-07-01

    Full Text Available Historically, several different approaches have been applied to explain the metabolic cost of uphill human running. Most of these approaches result in unrealistically high values for the efficiency of performing vertical work during running uphill, or are only valid for running up steep inclines. The purpose of this study was to reexamine the metabolic cost of uphill running, based upon our understanding of level running energetics and ground reaction forces during uphill running. In contrast to the vertical efficiency approach, we propose that during incline running at a certain velocity, the forces (and hence metabolic energy required for braking and propelling the body mass parallel to the running surface are less than during level running. Based on this idea, we propose that the metabolic rate during uphill running can be predicted by a model, which posits that (1 the metabolic cost of perpendicular bouncing remains the same as during level running, (2 the metabolic cost of running parallel to the running surface decreases with incline, (3 the delta efficiency of producing mechanical power to lift the COM vertically is constant, independent of incline and running velocity, and (4 the costs of leg and arm swing do not change with incline. To test this approach, we collected ground reaction force (GRF data for eight runners who ran thirty 30-second trials (velocity: 2.0–3.0 m/s; incline: 0–9°. We also measured the metabolic rates of eight different runners for 17, 7-minute trials (velocity: 2.0–3.0 m/s; incline: 0–8°. During uphill running, parallel braking GRF approached zero for the 9° incline trials. Thus, we modeled the metabolic cost of parallel running as exponentially decreasing with incline. With that assumption, best-fit parameters for the metabolic rate data indicate that the efficiency of producing mechanical power to lift the center of mass vertically was independent of incline and running velocity, with a value of ∼29

  9. Forces generated in guide-wires when drilling human bone.

    Science.gov (United States)

    Shuaib, I; Hillery, M

    1995-01-01

    In orthopaedic surgery guide-wires are extensively used for the drilling of pilot holes in human bones to allow further drilling, reaming and screw-tapping to take place in the repair and reconstruction of fractures. The guide-wires are generally 1.5 to 2.5 mm in diameter and have a three-faceted point with or without a screw thread. This paper describes drilling tests carried out using both types of guide-wire and these are compared with results obtained from a two-faceted geometry developed during this research. Tests were performed on the heads of femurs which had been removed during hip arthroplasty. A variable speed drilling machine together with a very sensitive drilling dynamometer were used for measuring the torque and thrust during the experimental stage of the research. This equipment was developed as part of an overall research programme into the mechanics of drilling of human bone. The indications are, firstly, that little advantage is gained by using a threaded-point guide-wire. In fact using a thread on the guide-wire can be a disadvantage. Secondly, the thrust cutting force is dependent on the spindle speed and feed. An optimum set of speeds of between 800 and 1400 r/min is recommended for 2.5 mm diameter guide-wires.

  10. Force generation in dividing E. coli cells : A handles-on approach using optical tweezers

    NARCIS (Netherlands)

    Verhoeven, Gertjan Sebastiaan

    2008-01-01

    In bacteria, what ‘drives’ the process of cell division is unknown. Possibly, forces generated by an internal protein ring (termed ‘the Z-ring’) are responsible for the division process, but direct evidence is lacking. Here we describe the development of a method to measure forces in a single

  11. Comparison of Two Methods for the Generation of Spatially Modulated Ultrasound Radiation Force

    OpenAIRE

    Elegbe, Etana C.; Menon, Manoj G.; McAleavey, Stephen A.

    2011-01-01

    Spatially modulated ultrasound radiation force (SMURF) imaging is an elastographic technique that involves generating a radiation force beam with a lateral intensity variation of a defined spatial frequency. This results in a shear wave of known wavelength. By using the displacements induced by the shear wave and standard Doppler or speckle-tracking methods, the shear wave frequency, and thus material shear modulus, is estimated. In addition to generating a pushing beam pattern with a specifi...

  12. Direct Observation of Phosphate Inhibiting the Force-Generating Capacity of a Miniensemble of Myosin Molecules

    Science.gov (United States)

    Debold, Edward P.; Walcott, Sam; Woodward, Mike; Turner, Matthew A.

    2013-01-01

    Elevated levels of phosphate (Pi) reduce isometric force, providing support for the notion that the release of Pi from myosin is closely associated with the generation of muscular force. Pi is thought to rebind to actomyosin in an ADP-bound state and reverse the force-generating steps, including the rotation of the lever arm (i.e., the powerstroke). Despite extensive study, this mechanism remains controversial, in part because it fails to explain the effects of Pi on isometric ATPase and unloaded shortening velocity. To gain new insight into this process, we determined the effect of Pi on the force-generating capacity of a small ensemble of myosin (∼12 myosin heads) using a three-bead laser trap assay. In the absence of Pi, myosin pulled the actin filament out of the laser trap an average distance of 54 ± 4 nm, translating into an average peak force of 1.2 pN. By contrast, in the presence of 30 mM Pi, myosin generated only enough force to displace the actin filament by 13 ± 1 nm, generating just 0.2 pN of force. The elevated Pi also caused a >65% reduction in binding-event lifetime, suggesting that Pi induces premature detachment from a strongly bound state. Definitive evidence of a Pi-induced powerstroke reversal was not observed, therefore we determined if a branched kinetic model in which Pi induces detachment from a strongly bound, postpowerstroke state could explain these observations. The model was able to accurately reproduce not only the data presented here, but also the effects of Pi on both isometric ATPase in muscle fibers and actin filament velocity in a motility assay. The ability of the model to capture the findings presented here as well as previous findings suggests that Pi-induced inhibition of force may proceed along a kinetic pathway different from that of force generation. PMID:24268149

  13. Examining the Preparatory Effects of Problem Generation and Solution Generation on Learning from Instruction

    Science.gov (United States)

    Kapur, Manu

    2018-01-01

    The goal of this paper is to isolate the preparatory effects of problem-generation from solution generation in problem-posing contexts, and their underlying mechanisms on learning from instruction. Using a randomized-controlled design, students were assigned to one of two conditions: (a) problem-posing with solution generation, where they…

  14. Screening for Gynecologic Conditions With Pelvic Examination: US Preventive Services Task Force Recommendation Statement.

    Science.gov (United States)

    Bibbins-Domingo, Kirsten; Grossman, David C; Curry, Susan J; Barry, Michael J; Davidson, Karina W; Doubeni, Chyke A; Epling, John W; García, Francisco A R; Kemper, Alex R; Krist, Alex H; Kurth, Ann E; Landefeld, C Seth; Mangione, Carol M; Phillips, William R; Phipps, Maureen G; Silverstein, Michael; Simon, Melissa; Siu, Albert L; Tseng, Chien-Wen

    2017-03-07

    Many conditions that can affect women's health are often evaluated through pelvic examination. Although the pelvic examination is a common part of the physical examination, it is unclear whether performing screening pelvic examinations in asymptomatic women has a significant effect on disease morbidity and mortality. To issue a new US Preventive Services Task Force (USPSTF) recommendation on screening for gynecologic conditions with pelvic examination for conditions other than cervical cancer, gonorrhea, and chlamydia, for which the USPSTF has already made specific recommendations. The USPSTF reviewed the evidence on the accuracy, benefits, and potential harms of performing screening pelvic examinations in asymptomatic, nonpregnant adult women 18 years and older who are not at increased risk for any specific gynecologic condition. Overall, the USPSTF found inadequate evidence on screening pelvic examinations for the early detection and treatment of a range of gynecologic conditions in asymptomatic, nonpregnant adult women. The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of performing screening pelvic examinations in asymptomatic, nonpregnant adult women. (I statement) This statement does not apply to specific disorders for which the USPSTF already recommends screening (ie, screening for cervical cancer with a Papanicolaou smear, screening for gonorrhea and chlamydia).

  15. Forces and moments generated by removable thermoplastic aligners: incisor torque, premolar derotation, and molar distalization.

    Science.gov (United States)

    Simon, Mareike; Keilig, Ludger; Schwarze, Jörg; Jung, Britta A; Bourauel, Christoph

    2014-06-01

    The exact force systems as well as their progressions generated by removable thermoplastic appliances have not been investigated. Thus, the purposes of this experimental study were to quantify the forces and moments delivered by a single aligner and a series of aligners (Invisalign; Align Technology, Santa Clara, Calif) and to investigate the influence of attachments and power ridges on the force transfer. We studied 970 aligners of the Invisalign system (60 series of aligners). The aligners came from 30 consecutive patients, of which 3 tooth movements (incisor torque, premolar derotation, molar distalization) with 20 movements each were analyzed. The 3 movement groups were subdivided so that 10 movements were supported with an attachment and 10 were not. The patients' ClinCheck (Align Technology, Santa Clara, Calif) was planned so that the movements to be investigated were performed in isolation in the respective quadrant. Resin replicas of the patients' intraoral situation before the start of the investigated movement were taken and mounted in a biomechanical measurement system. An aligner was put on the model, the force systems were measured, and the calculated movements were experimentally performed until no further forces or moments were generated. Subsequently, the next aligners were installed, and the measurements were repeated. The initial mean moments were about 7.3 N·mm for maxillary incisor torque and about 1.0 N for distalization. Significant differences in the generated moments were measured in the premolar derotation group, whether they were supported with an attachment (8.8 N·mm) or not (1.2 N·mm). All measurements showed an exponential force change. Apart from a few maximal initial force systems, the forces and moments generated by aligners of the Invisalign system are within the range of orthodontic forces. The force change is exponential while a patient is wearing removable thermoplastic appliances. Copyright © 2014 American Association of

  16. Examination of incentive mechanisms for innovative technologies applicable to utility and nonutility power generators

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, K.A. [Illinois Commerce Commission, Springfield, IL (United States); Bailey, K.A.; South, D.W. [Argonne National Lab., IL (United States). Environmental Assessment and Information Sciences Div.

    1993-08-01

    Innovative technologies, built by either utility or nonutility power generators, have the potential to lower costs with less environmental emissions than conventional technologies. However, the public-good nature of information, along with uncertain costs, performance, and reliability, discourages rapid adoption of these technologies. The effect of regulation of electricity production may also have an adverse impact on motivation to innovate. Slower penetration of cleaner, more efficient technologies could result in greater levels of pollution, higher electricity prices, and a reduction in international competitiveness. Regulatory incentives could encourage adoption and deployment of innovative technologies of all kinds, inducting clean coal technologies. Such incentives must be designed to offset risks inherent in innovative technology and encourage cost-effective behavior. To evaluate innovative and conventional technologies equally, the incremental cost of risk (ICR) of adopting the innovative technology must be determined. Through the ICR, the magnitude of incentive required to make a utility (or nonutility) power generator equally motivated to use either conventional or innovative technologies can be derived. Two technology risks are examined: A construction risk, represented by a 15% cost overrun, and an operating risk, represented by a increased forced outage rate (decreased capacity factor). Different incentive mechanisms and measurement criteria are used to assess the effects of these risks on ratepayers and shareholders. In most cases, a regulatory incentive could offset the perceived risks while encouraging cost-effective behavior by both utility and nonutility power generators. Not only would the required incentive be recouped, but the revenue requirements would be less for the innovative technology; also, less environmental pollution would be generated. In the long term, ratepayers and society would benefit from innovative technologies.

  17. Insufficient joint forces of first-generation articulating instruments for laparoendoscopic single-site surgery.

    Science.gov (United States)

    Jeong, Chang Wook; Kim, Sung Hoon; Kim, Hyung Tae; Jeong, Seong Jin; Hong, Sung Kyu; Byun, Seok-Soo; Lee, Sang Eun

    2013-10-01

    The current articulating instruments used in laparoendoscopic single-site surgery do not appear to provide the joint forces required. Thus, we measured the joint forces of first-generation articulating laparoscopic instruments. To compare these forces with those necessary in the surgical context, we evaluated the forces sufficient to produce secure surgical ties in an animal model. The articulating instruments tested were Laparo-Angle (Cambridge Endoscopic Devices Inc, Framingham, MA), RealHand (Novare Surgical Systems Inc, Cupertino, CA), and Roticulator (Covidien Inc, Mansfield, MA). For each, we measured the angle between the end-effector and the shaft in proportion to the articulating force using a push-pull gauge. Two fixed-position configurations of the instruments were predetermined: the neutral and the fully articulated positions. The forces required to secure surgical ties for the ureter, renal artery, and renal vein were evaluated using kidneys harvested from a female pig. The bending forces required to bend from the neutral position to 30° were 5.6 ± 1.2 and 4.7 ± 1.0 N with the Laparo-Angle and RealHand, respectively. Furthermore, the slippage forces in the fully articulated state were 1.8 ± 0.3, 1.6 ± 0.2, and 1.5 ± 0.2 N in the above order. In contrast, the mean forces to produce surgical ties of the ureter, renal artery, and renal vein were 14.5 ± 2.3, 11.5 ± 0.8, and 10.3 ± 2.3 N, respectively. The joint forces of first-generation articulating instruments for laparoendoscopic single-site surgery are not sufficient to meet the usual operative needs. Improved articulating instruments with greater articulating forces should be developed.

  18. A novel 3D fibril force assay implicates src in tumor cell force generation in collagen networks.

    Directory of Open Access Journals (Sweden)

    Robert J Polackwich

    Full Text Available New insight into the biomechanics of cancer cell motility in 3D extracellular matrix (ECM environments would significantly enhance our understanding of aggressive cancers and help identify new targets for intervention. While several methods for measuring the forces involved in cell-matrix interactions have been developed, previous to this study none have been able to measure forces in a fibrillar environment. We have developed a novel assay for simultaneously measuring cell mechanotransduction and motility in 3D fibrillar environments. The assay consists of a controlled-density fibrillar collagen gel atop a controlled-stiffness polyacrylamide (PAA surface. Forces generated by living cells and their migration in the 3D collagen gel were measured with the 3D motion of tracer beads within the PAA layer. Here, this 3D fibril force assay is used to study the role of the invasion-associated protein kinase Src in mechanotransduction and motility. Src expression and activation are linked with proliferation, invasion, and metastasis, and have been shown to be required in 2D for invadopodia membranes to direct and mediate invasion. Breast cancer cell line MDA-MD-231 was stably transfected with GFP-tagged constitutively active Src or wild-type Src. In 3D fibrillar collagen matrices we found that, relative to wild-type Src, constitutively active Src: 1 increased the strength of cell-induced forces on the ECM, 2 did not significantly change migration speed, and 3 increased both the duration and the length, but not the number, of long membrane protrusions. Taken together, these results support the hypothesis that Src controls invasion by controlling the ability of the cell to form long lasting cellular protrusions to enable penetration through tissue barriers, in addition to its role in promoting invadopodia matrix-degrading activity.

  19. A Novel 3D Fibril Force Assay Implicates Src in Tumor Cell Force Generation in Collagen Networks

    Science.gov (United States)

    Polackwich, Robert J.; Koch, Daniel; Arevalo, Richard; Miermont, Anne M.; Jee, Kathleen J.; Lazar, John; Urbach, Jeffrey; Mueller, Susette C.; McAllister, Ryan G.

    2013-01-01

    New insight into the biomechanics of cancer cell motility in 3D extracellular matrix (ECM) environments would significantly enhance our understanding of aggressive cancers and help identify new targets for intervention. While several methods for measuring the forces involved in cell-matrix interactions have been developed, previous to this study none have been able to measure forces in a fibrillar environment. We have developed a novel assay for simultaneously measuring cell mechanotransduction and motility in 3D fibrillar environments. The assay consists of a controlled-density fibrillar collagen gel atop a controlled-stiffness polyacrylamide (PAA) surface. Forces generated by living cells and their migration in the 3D collagen gel were measured with the 3D motion of tracer beads within the PAA layer. Here, this 3D fibril force assay is used to study the role of the invasion-associated protein kinase Src in mechanotransduction and motility. Src expression and activation are linked with proliferation, invasion, and metastasis, and have been shown to be required in 2D for invadopodia membranes to direct and mediate invasion. Breast cancer cell line MDA-MD-231 was stably transfected with GFP-tagged constitutively active Src or wild-type Src. In 3D fibrillar collagen matrices we found that, relative to wild-type Src, constitutively active Src: 1) increased the strength of cell-induced forces on the ECM, 2) did not significantly change migration speed, and 3) increased both the duration and the length, but not the number, of long membrane protrusions. Taken together, these results support the hypothesis that Src controls invasion by controlling the ability of the cell to form long lasting cellular protrusions to enable penetration through tissue barriers, in addition to its role in promoting invadopodia matrix-degrading activity. PMID:23536784

  20. Numerical Study of Balearic Meteotsunami Generation and Propagation under Synthetic Gravity Wave Forcing

    Science.gov (United States)

    Licer, Matjaz; Mourre, Baptiste; Troupin, Charles; Krietemeyer, Andreas; Tintoré, Joaquín

    2017-04-01

    A high resolution nested ocean modelling system forced by synthetic atmospheric gravity waves is used to investigate meteotsunami generation, amplification and propagation properties over the Mallorca-Menorca shelf (Balearic Islands, Western Mediterranean Sea). We determine how meteotsunami amplitude outside and inside of the Balearic port of Ciutadella depends on forcing gravity wave direction, speed and trajectory. Contributions of Mallorca shelves and Menorca Channel are quantified for different gravity wave forcing angles and speeds. Results indicate that the Channel is the key build-up region and that Northern and Southern Mallorca shelves do not significantly contribute to the amplitude of substantial harbour oscillations in Ciutadella. This fact seriously reduces early-warning alert times in cases of locally generated pressure perturbations. Tracking meteotsunami propagation paths in the Menorca Channel for several forcing velocities, we show that the Channel bathymetry serves as a focusing lens for meteotsunami waves whose paths are constrained by the forcing direction. Faster meteotsunamis are shown to propagate over deeper ocean regions, as required by the Proudman resonance. Meteotsunami speed under sub- and supercritical forcing is estimated and a first order estimate of its magnitude is derived. Meteotsunamis generated by the supercritical gravity waves are found to propagate with a velocity which is equal to an arithmetic mean of the gravity wave speed and local ocean barotropic wave speed.

  1. Earth Mothers (and Fathers): Examining Generativity and Environmental Concerns in Adolescents and Their Parents

    Science.gov (United States)

    Pratt, Michael W.; Norris, Joan E.; Alisat, Susan; Bisson, Elise

    2013-01-01

    Erikson's construct of generative concern for future generations seems a plausible structure for supporting environmental behavior and socialization in the family. The present study of 44 Canadian middle-class families with a focal child aged 14-16 years, examined variations in generative concern among parents and their children and tested how…

  2. Periodic Screening Pelvic Examination: Evidence Report and Systematic Review for the US Preventive Services Task Force.

    Science.gov (United States)

    Guirguis-Blake, Janelle M; Henderson, Jillian T; Perdue, Leslie A

    2017-03-07

    Recent changes in the periodicity of cervical cancer screening have led to questions about the role of screening pelvic examinations among asymptomatic women. To systematically review literature on health benefits, accuracy, and harms of the screening pelvic examination for gynecologic conditions for the US Preventive Services Task Force (USPSTF). MEDLINE, PubMed, and Cochrane Central Register of Controlled Trials for relevant English-language studies published through January 13, 2016, with surveillance through August 3, 2016. Two reviewers independently screened abstracts and studies. The search yielded 8678 unique citations; 316 full-text articles were reviewed, and 9 studies including 27 630 patients met inclusion criteria. Two reviewers rated study quality using USPSTF criteria. Morbidity; mortality; diagnostic accuracy for any gynecologic cancer or condition except cervical cancer, gonorrhea, and chlamydia, which are covered by other USPSTF screening recommendations; harms (false-positive rates, false-negative rates, surgery rates). No trials examined the effectiveness of the pelvic examination in reducing all-cause mortality, reducing cancer- and disease-specific morbidity and mortality, or improving quality of life. Eight studies reported accuracy for the screening pelvic examination: ovarian cancer (4 studies; n = 26 432), bacterial vaginosis (2 studies; n = 930), trichomoniasis (1 study; n = 779), and genital herpes (1 study; n = 779). In the 4 ovarian cancer screening studies, low prevalence of ovarian cancer consistently resulted in low positive predictive values (PPVs) and false-positive rates, with a lack of precision in accuracy estimates (sensitivity range, 0%-100%; specificity range, 91%-99%; PPV range, 0%-3.6%; negative predictive value [NPV] range, ≥99%). Each diagnostic accuracy study for bacterial vaginosis, trichomoniasis, and genital herpes was performed in a high-prevalence population with substantial proportions of

  3. Cogging force investigation of a free piston permanent magnet linear generator

    Science.gov (United States)

    Abdalla, I. I.; Zainal, A. E. Z.; Ramlan, N. A.; Firmansyah; Aziz, A. R. A.; Heikal, M. R.

    2017-10-01

    Better performance and higher efficiency of the vehicles can be achieved by using free piston engine, in which the piston is connected directly to the linear generator and waiving of any mechanical means. The free piston engine has the ability to overcome or reduce many of the challenges, such as the carbon dioxide (CO2) emission and fossil fuel consumption. The cogging force produces undesired vibration and acoustic noise in the generator. However, the cogging force must be minimized as much as possible, in order to have a high performance. This paper studies the effects of ferromagnetic materials on the cogging force of the permanent magnet linear generator (PMLG) to be used in a free piston engine using nonlinear finite-element analysis (FEA) under ANSYS Maxwell. The comparisons have been established for the cogging force of the PMLG under various translator velocities and three different ferromagnetic materials for the stator core, namely, Silicon Steel laminations, Mild Steel and Somaloy. It has been shown that the PMLG with a stator core made of Somaloy has a lower cogging force among them. Furthermore, the induced voltage of the PMLG at different accelerations has been studied. It is found that the PMLG with Mild Steel and Somaloy, respectively give larger induced voltage. Moreover, as the translator speed increase the induced voltage increased.

  4. Guidelines for random excitation forces due to cross flow in steam generators

    International Nuclear Information System (INIS)

    Taylor, C.E.; Pettigrew, M.J.

    1998-01-01

    Random excitation forces can cause low-amplitude tube motion that will result in long-term fretting-wear or fatigue. To prevent these tube failures in steam generators and other heat exchangers, designers and trouble-shooters must have guidelines that incorporate random or turbulent fluid forces. Experiments designed to measure fluid forces have been carried out at Chalk River Laboratories and at other labs around the world. The data from these experiments have been studied and collated to determine suitable guidelines for random excitation forces. In this paper, a guideline for random excitation forces in single-phase cross flow is presented in the form of normalised spectra that are applicable to a wide range of flow conditions and tube frequencies. In particular, the experimental results used in this study were carried out over the full range of flow conditions found in a nuclear steam generator. The proposed guidelines are applicable to steam generators, condensers, reheaters and other shell-and-tube heat exchangers. They may be used for flow-induced vibration analysis of new or existing components, as input to vibration analysis computer codes and as specifications in procurement documents. (author)

  5. On convergence generation in computing the electro-magnetic Casimir force

    International Nuclear Information System (INIS)

    Schuller, F.

    2008-01-01

    We tackle the very fundamental problem of zero-point energy divergence in the context of the Casimir effect. We calculate the Casimir force due to field fluctuations by using standard cavity radiation modes. The validity of convergence generation by means of an exponential energy cut-off factor is discussed in detail. (orig.)

  6. A comparative assessment of forces and moments generated by lingual and conventional brackets

    NARCIS (Netherlands)

    Sifakakis, I.; Pandis, N.; Makou, M.; Katsaros, C.; Eliades, T.; Bourauel, C.

    2013-01-01

    The aim of this study was to assess the effect of bracket type on the labiopalatal forces and moments generated in the sagittal plane. Incognito lingual brackets (3M Unitek), STb lingual brackets (Light Lingual System; ORMCO), and conventional 0.018 inch slot brackets (Gemini; 3M Unitek) were bonded

  7. The proton motive force generated in Leuconostoc oenos by L-malate fermentation

    NARCIS (Netherlands)

    Salema, Madalena; Lolkema, Juke S.; San Romão, M.V.; Loureiro Dias, Maria C.

    In cells of Leuconostoc oenos, the fermentation of L-malic acid generates both a transmembrane pH gradient, inside alkaline, and an electrical potential gradient, inside negative. In resting cells, the proton motive force ranged from -170 mV to -88 mV between pH 3.1 and 5.6 in the presence of

  8. Cogging Force Issues of Permanent Magnet Linear Generator for Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Izzeldin Idris Abdalla

    2017-09-01

    Full Text Available Alternatives to hydraulic drives that used on vehicles are necessary in order to reduce the Carbon dioxide (CO2 emission and oil consumption. Hence better performance and efficiency of the vehicles can be achieved by using free piston engine, in which the piston reciprocate linearly with a permanent magnet linear generator (PMLG without the need of a crankshaft. The PMLG has high performance, but suffering from the cogging force. The cogging force induces undesired vibration and acoustic noise and makes a ripple in the thrust force. Moreover, the cogging force deteriorates the control characteristics, particularly in terms of the position control and speed precisely. This paper proposes Somaloy to replace the laminated silicon steel sheets in order to reduce the cogging force in a PMLG. Through a finite-element analysis, it has been shown that, the stator core made of Somaloy minimizes the cogging force of the PMLG, moreover, giving larger flux-linkage and back-electromotive force (B-EMF, respectively.

  9. Examination of E-3 AWACS Readiness Spares Kit Adequacy During Operation Allied Force

    National Research Council Canada - National Science Library

    McCormick, David

    2000-01-01

    ... readiness spares kits during Operation ALLIED FORCE. Also, FY 1999 summary readiness indicator statistics for the E-3 fleet, at different deployed locations and home station, before, during, and after ALLIED FORCE are presented...

  10. Examining effective factors on human forces' productivity in bureau of naval operations

    Directory of Open Access Journals (Sweden)

    Younes Bahadori

    2015-01-01

    Full Text Available This research aims at examining effective factors on improvement of human forces' productivity and determining degree of influence and importance of each group among factors including workshop equipment and arrangement in organization, system of control and supervision on employees, degree of employees training, occupational value of employees and at last, administrating meritocracy system on improvement of human forces' productivity. Statistical population is composed of bureau of naval operations' employees in oil terminals' company in Khark, Iran. Statistical population has been 230, among which 135 people were determined as statistical sample size using Cochran formula. Survey instrument in this research has been questionnaire, according to which employees' ideas about effective factors on employees' productivity were evaluated. These questionnaires completed by people among statistical sample contain 16 close questions which were set up according to Likert 5-grade scale and were distributed as 135 numbers that after returning questionnaire, statistical analysis and data processing were accomplished. Analysis was performed in 2 descriptive and inferential statistics levels. Results of data analysis show that: A 5-fold factors under review “workshop equipment and arrangement of organization, system of control and supervision on employees, degree of employees training, occupational value of employees and administrating meritocracy related to human resources by management” have had effects on improvement of employees' productivity as average. B degree of employees training and then occupational value of employees and administrating meritocracy system have had the most influence, and workshop equipment and arrangement of organization and system of control and supervision on employees have had the least influence.

  11. Comparison of Forced-Alignment Speech Recognition and Humans for Generating Reference VAD

    DEFF Research Database (Denmark)

    Kraljevski, Ivan; Tan, Zheng-Hua; Paola Bissiri, Maria

    2015-01-01

    This present paper aims to answer the question whether forced-alignment speech recognition can be used as an alternative to humans in generating reference Voice Activity Detection (VAD) transcriptions. An investigation of the level of agreement between automatic/manual VAD transcriptions...... and the reference ones produced by a human expert was carried out. Thereafter, statistical analysis was employed on the automatically produced and the collected manual transcriptions. Experimental results confirmed that forced-alignment speech recognition can provide accurate and consistent VAD labels....

  12. Using the Kaleidoscope Career Model to Examine Generational Differences in Work Attitudes

    Science.gov (United States)

    Sullivan, Sherry E.; Forret, Monica L.; Carraher, Shawn M.; Mainiero, Lisa A.

    2009-01-01

    Purpose: The purpose of this paper is to examine, utilising the Kaleidoscope Career Model, whether members of the Baby Boom generation and Generation X differ in their needs for authenticity, balance, and challenge. Design/methodology/approach: Survey data were obtained from 982 professionals located across the USA. Correlations, t-tests, and…

  13. Comparison of two methods for the generation of spatially modulated ultrasound radiation force.

    Science.gov (United States)

    Elegbe, Etana C; Menon, Manoj G; McAleavey, Stephen A

    2011-07-01

    Spatially modulated ultrasound radiation force (SMURF) imaging is an elastographic technique that involves generating a radiation force beam with a lateral intensity variation of a defined spatial frequency. This results in a shear wave of known wavelength. By using the displacements induced by the shear wave and standard Doppler or speckle-tracking methods, the shear wave frequency, and thus material shear modulus, is estimated. In addition to generating a pushing beam pattern with a specified lateral intensity variation, it is generally desirable to induce larger displacements so that the displacement data signal-to-noise ratio is higher. We provide an analysis of two beam forming methods for generating SMURF in an elastic material: the focal Fraunhofer and intersecting plane wave methods. Both techniques generate beams with a defined spatial frequency. However, as a result of the trade-offs associated with each technique, the peak acoustic intensity outputs in the region of interest differs for the same combinations of parameters (e.g., the focal depth, the width of the area of interest, and ultrasonic attenuation coefficient). Assuming limited transducer drive voltage, we provide a decision plot to determine which of the two techniques yields the greater pushing force for a specific configuration.

  14. Improving nuclear utility generation capacity, understanding the sources of forced outage and learning how to prevent them

    International Nuclear Information System (INIS)

    Brodeur, D.L.; Todreas, N.E.; Angus, V.T.

    1998-01-01

    MIT and PECO Energy have completed a detailed examination of the sources of forced outages at the Limerick Generating Station (LGS) Boiling Water Reactor Class IV (BWR IV) site over a five year period and contrasted that information to similar BWR IV utilities in the United States over the same period. Each forced outage was attributed to one system and assigned causal codes of equipment versus human factors and failure attributes such as weak design, poor craftsmanship, and worn parts. It was found that fifty four percent of the lost power at LGS was the result of Balance of Plant failures. Industry wide data identifies fifty nine percent of the lost power as attributed to Balance of Plant failures. Balance of Plant systems are those systems not included in the primary and safety related system category. Considering failure causal factors, forty six percent of the lost power at the utility under study was the result of equipment factors such as weak design or worn parts. Significantly, the study showed a high variance between those systems which caused significant forced outage at the two sister LGS units. This demonstrated the infrequent nature of plant forced outages within a given system. This was supported by the observation that dominant systems attributing to forced outage at LGS were not equally represented in industry data. It is suggested that for individual utilities to dramatically improve unit capability factors with regard to Balance of Plant systems, they must learn from industry wide experiences and develop cooperative means of exchanging lessons learned among similarly designed plants and systems. With the broad knowledge base of system failures, current designs must be frequently assessed and altered until each system poses an acceptable level of risk to generation capacity. (author)

  15. Enhancement of force generated by individual myosin heads in skinned rabbit psoas muscle fibers at low ionic strength.

    Science.gov (United States)

    Sugi, Haruo; Abe, Takahiro; Kobayashi, Takakazu; Chaen, Shigeru; Ohnuki, Yoshiki; Saeki, Yasutake; Sugiura, Seiryo

    2013-01-01

    Although evidence has been presented that, at low ionic strength, myosin heads in relaxed skeletal muscle fibers form linkages with actin filaments, the effect of low ionic strength on contraction characteristics of Ca(2+)-activated muscle fibers has not yet been studied in detail. To give information about the mechanism of muscle contraction, we have examined the effect of low ionic strength on the mechanical properties and the contraction characteristics of skinned rabbit psoas muscle fibers in both relaxed and maximally Ca(2+)-activated states. By progressively decreasing KCl concentration from 125 mM to 0 mM (corresponding to a decrease in ionic strength μ from 170 mM to 50 mM), relaxed fibers showed changes in mechanical response to sinusoidal length changes and ramp stretches, which are consistent with the idea of actin-myosin linkage formation at low ionic strength. In maximally Ca(2+)-activated fibers, on the other hand, the maximum isometric force increased about twofold by reducing KCl concentration from 125 to 0 mM. Unexpectedly, determination of the force-velocity curves indicated that, the maximum unloaded shortening velocity Vmax, remained unchanged at low ionic strength. This finding indicates that the actin-myosin linkages, which has been detected in relaxed fibers at low ionic strength, are broken quickly on Ca(2+) activation, so that the linkages in relaxed fibers no longer provide any internal resistance against fiber shortening. The force-velocity curves, obtained at various levels of steady Ca(2+)-activated isometric force, were found to be identical if they are normalized with respect to the maximum isometric force. The MgATPase activity of muscle fibers during isometric force generation was found not to change appreciably at low ionic strength despite the two-fold increase in Ca(2+)-activated isometric force. These results can be explained in terms of enhancement of force generated by individual myosin heads, but not by any changes in

  16. Enhancement of force generated by individual myosin heads in skinned rabbit psoas muscle fibers at low ionic strength.

    Directory of Open Access Journals (Sweden)

    Haruo Sugi

    Full Text Available Although evidence has been presented that, at low ionic strength, myosin heads in relaxed skeletal muscle fibers form linkages with actin filaments, the effect of low ionic strength on contraction characteristics of Ca(2+-activated muscle fibers has not yet been studied in detail. To give information about the mechanism of muscle contraction, we have examined the effect of low ionic strength on the mechanical properties and the contraction characteristics of skinned rabbit psoas muscle fibers in both relaxed and maximally Ca(2+-activated states. By progressively decreasing KCl concentration from 125 mM to 0 mM (corresponding to a decrease in ionic strength μ from 170 mM to 50 mM, relaxed fibers showed changes in mechanical response to sinusoidal length changes and ramp stretches, which are consistent with the idea of actin-myosin linkage formation at low ionic strength. In maximally Ca(2+-activated fibers, on the other hand, the maximum isometric force increased about twofold by reducing KCl concentration from 125 to 0 mM. Unexpectedly, determination of the force-velocity curves indicated that, the maximum unloaded shortening velocity Vmax, remained unchanged at low ionic strength. This finding indicates that the actin-myosin linkages, which has been detected in relaxed fibers at low ionic strength, are broken quickly on Ca(2+ activation, so that the linkages in relaxed fibers no longer provide any internal resistance against fiber shortening. The force-velocity curves, obtained at various levels of steady Ca(2+-activated isometric force, were found to be identical if they are normalized with respect to the maximum isometric force. The MgATPase activity of muscle fibers during isometric force generation was found not to change appreciably at low ionic strength despite the two-fold increase in Ca(2+-activated isometric force. These results can be explained in terms of enhancement of force generated by individual myosin heads, but not by any

  17. Enhanced electrohydrodynamic force generation in a two-stroke cycle dielectric-barrier-discharge plasma actuator

    Science.gov (United States)

    Sato, Shintaro; Takahashi, Masayuki; Ohnishi, Naofumi

    2017-05-01

    An approach for electrohydrodynamic (EHD) force production is proposed with a focus on a charge cycle on a dielectric surface. The cycle, consisting of positive-charging and neutralizing strokes, is completely different from the conventional methodology, which involves a negative-charging stroke, in that the dielectric surface charge is constantly positive. The two-stroke charge cycle is realized by applying a DC voltage combined with repetitive pulses. Simulation results indicate that the negative pulse eliminates the surface charge accumulated during constant voltage phase, resulting in repetitive EHD force generation. The time-averaged EHD force increases almost linearly with increasing repetitive pulse frequency and becomes one order of magnitude larger than that driven by the sinusoidal voltage, which has the same peak-to-peak voltage.

  18. Does the stress generation hypothesis apply to eating disorders?: an examination of stress generation in eating, depressive, and anxiety symptoms.

    Science.gov (United States)

    Bodell, Lindsay P; Hames, Jennifer L; Holm-Denoma, Jill M; Smith, April R; Gordon, Kathryn H; Joiner, Thomas E

    2012-12-15

    The stress generation hypothesis posits that individuals actively contribute to stress in their lives. Although stress generation has been studied frequently in the context of depression, few studies have examined whether this stress generation process is unique to depression or whether it occurs in other disorders. Although evidence suggests that stress contributes to the development of eating disorders, it is unclear whether eating disorders contribute to subsequent stress. A prospective design was used to examine the influence of eating disorder symptoms on negative life stressors. Two hundred and ninety female undergraduates completed questionnaires at two time points that examined eating disorder, depressive and anxiety symptoms and the presence of negative life events. Regression analyses found that while eating disorder symptoms (i.e. bulimic symptoms and drive for thinness) were independent, significant predictors of negative life events, they did not predict negative life events above and beyond symptoms of depression. Limitations include the use of self-report measures and a college-based sample, which may limit generalizability of the results. Findings suggest that if stress generation is present in individuals with symptoms of eating disorders, it is likely attributable to symptoms of depression. Thus, it may be important for clinicians to target depressive symptoms in order to reduce the frequency of negative life stressors among individuals with eating disorders. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Determination of the attractive force, adhesive force, adhesion energy and Hamaker constant of soot particles generated from a premixed methane/oxygen flame by AFM

    Science.gov (United States)

    Liu, Ye; Song, Chonglin; Lv, Gang; Chen, Nan; Zhou, Hua; Jing, Xiaojun

    2018-03-01

    Atomic force microscopy (AFM) was used to characterize the attractive force, adhesive force and adhesion energy between an AFM probe tip and nanometric soot particle generated by a premixed methane/oxygen flame. Different attractive force distributions were found when increasing the height above burner (HAB), with forces ranging from 1.1-3.5 nN. As the HAB was increased, the average attractive force initially increased, briefly decreased, and then underwent a gradual increase, with a maximum of 2.54 nN observed at HAB = 25 mm. The mean adhesive force was 6.5-7.5 times greater than the mean attractive force at the same HAB, and values were in the range of 13.5-24.5 nN. The adhesion energy was in the range of 2.0-5.6 × 10-17 J. The variations observed in the average adhesion energy with increasing HAB were different from those of the average adhesion force, implying that the stretched length of soot particles is an important factor affecting the average adhesion energy. The Hamaker constants of the soot particles generated at different HABs were determined from AFM force-separation curves. The average Hamaker constant exhibited a clear correlation with the graphitization degree of soot particles as obtained from Raman spectroscopy.

  20. Generated forces and heat during the critical stages of friction stir welding and processing

    International Nuclear Information System (INIS)

    Hussein, Sadiq Aziz; Tahir, Abd Salam Md; Izamshah, R.

    2015-01-01

    The solid-state behavior of friction stir welding process results in violent mechanical forces that should be mitigated, if not eliminated. Plunging and dwell time are the two critical stages of this welding process in terms of the generated forces and the related heat. In this study, several combinations of pre-decided penetration speeds, rotational speeds, tool designs, and dwell time periods were used to investigate these two critical stages. Moreover, a coupled-field thermal-structural finite element model was developed to validate the experimental results and the induced stresses. The experimental results revealed the relatively large changes in force and temperature during the first two stages compared with those during the translational tool movement stage. An important procedure to mitigate the undesired forces was then suggested. The model prediction of temperature values and their distribution were in good agreement with the experimental prediction. Therefore, the thermal history of this non-uniform heat distribution was used to estimate the induced thermal stresses. Despite the 37% increase in these stresses when 40 s dwell time was used instead of 5 s, these stresses showed no effect on the axial force values because of the soft material incidence and stir effects

  1. Generated forces and heat during the critical stages of friction stir welding and processing

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Sadiq Aziz; Tahir, Abd Salam Md; Izamshah, R. [University Teknikal Malaysia Melaka, Malacca (Malaysia)

    2015-10-15

    The solid-state behavior of friction stir welding process results in violent mechanical forces that should be mitigated, if not eliminated. Plunging and dwell time are the two critical stages of this welding process in terms of the generated forces and the related heat. In this study, several combinations of pre-decided penetration speeds, rotational speeds, tool designs, and dwell time periods were used to investigate these two critical stages. Moreover, a coupled-field thermal-structural finite element model was developed to validate the experimental results and the induced stresses. The experimental results revealed the relatively large changes in force and temperature during the first two stages compared with those during the translational tool movement stage. An important procedure to mitigate the undesired forces was then suggested. The model prediction of temperature values and their distribution were in good agreement with the experimental prediction. Therefore, the thermal history of this non-uniform heat distribution was used to estimate the induced thermal stresses. Despite the 37% increase in these stresses when 40 s dwell time was used instead of 5 s, these stresses showed no effect on the axial force values because of the soft material incidence and stir effects.

  2. Examination of biogenic selenium-containing nanosystems based on polyelectrolyte complexes by atomic force, Kelvin probe force and electron microscopy methods

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanova, T. E., E-mail: tat-sukhanova@mail.ru; Vylegzhanina, M. E.; Valueva, S. V.; Volkov, A. Ya.; Kutin, A. A. [Institute of Macromolecular Compounds RAS, 199004 Bolshoy Pr., 31, St.-Petersburg (Russian Federation); Temiryazeva, M. P.; Temiryazev, A. G. [Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch) Russian Academy of Sciences, Fryazino, Moscow region, 141190 (Russian Federation)

    2016-06-17

    The morphology and electrical properties of biogenic selenium-containing nanosystems based on polyelectrolyte complexes (PECs) were examined using AFM, Kelvin Probe Force and electron microscopy methods. It has been found, that prepared nanostructures significantly differed in their morphological types and parameters. In particular, multilayers capsules can be produced via varying synthesis conditions, especially, the selenium–PEC mass ratio ν. At the “special point” (ν = 0.1), filled and hollow nano- and microcapsules are formed in the system. The multilayer character of the capsules walls is visible in the phase images. Kelvin Probe Force images showed the inhomogeneity of potential distribution in capsules and outside them.

  3. Amplification of disturbances generated by localized body forces in channel flows of viscoelastic fluids

    Science.gov (United States)

    Hariharan, Gokul; Jovanovic, Mihailo; Kumar, Satish

    2017-11-01

    The study of non-modal amplification of distributed body forces in channel flows of viscoelastic fluids has provided useful insight into the mechanisms that may govern the initial stages of transition to elastic turbulence. However, distributed body forces are not easy to implement in experiments and there is a need to examine amplification of localized body forces. In this work, we use the linearized governing equations to examine such amplification in plane Poiseuille flow of FENE-CR fluids. We first identify the location at which the impulsive excitations experience the largest amplification and then analyze the energy of the fluctuations and resulting flow structures. For both a Newtonian fluid at high Reynolds number and a viscoelastic fluid at low Reynolds number, the largest amplification occurs for disturbances that are located near the channel wall. Analysis of the energy evolution shows that the localized point force directed in the spanwise direction has the largest impact and that the streamwise velocity is most affected. For viscoelastic fluids we observe the development of vortical structures away from the source of impulsive excitation, a feature absent in Newtonian fluids that may provide a mechanism for the initial stages of transition to elastic turbulence.

  4. An examination of electricity generation by utility organizations in the Southeast United States

    International Nuclear Information System (INIS)

    Craig, Christopher A.; Feng, Song

    2016-01-01

    This study examined the impact of climatic variability on electricity generation in the Southeast United States. The relationship cooling degree days (CDD) and heating degree days (HDD) shared with electricity generation by fuel source was explored. Using seasonal autoregressive integrated weighted average (ARIMA) and seasonal simple exponentially smoothed models, retrospective time series analysis was run. The hypothesized relationship between climatic variability and total electricity generation was supported, where an ARIMA model including CDDs as a predictor explained 57.6% of the variability. The hypothesis that climatic variability would be more predictive of fossil fuel electricity generation than electricity produced by clean energy sources was partially supported. The ARIMA model for natural gas indicated that CDDS were the only predictor for the fossil fuel source, and that 79.4% of the variability was explained. Climatic variability was not predictive of electricity generation from coal or petroleum, where simple seasonal exponentially smoothed models emerged. However, HDDs were a positive predictor of hydroelectric electricity production, where 48.9% of the variability in the clean energy source was explained by an ARIMA model. Implications related to base load electricity from fossil fuels, and future electricity generation projections relative to extremes and climate change are discussed. - Highlights: • Models run to examine impact of climatic variability on electricity generation. • Cooling degree days explained 57.6% of variability in total electricity generation. • Climatic variability was not predictive of coal or petroleum generation. • Cooling degree days explained 79.4% of natural gas generation. • Heating degree days were predictive of nuclear and hydroelectric generation.

  5. Rise in legal skirmishes and intellectual property protectionism force companies to re-examine technology policy

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2006-12-15

    The possession of intellectual property (IP) has become an important part of a technologically advanced oil and gas industry. Firms that specialize in IP law are now aiding oil and gas companies to establish company-wide IP policies to protect their inventions and properly profit from them. However, many companies do not have a clear policy to report on the commercial value of their IP assets or keep track of efforts made to gain value from them. A patent policy could require that patents be applied for only when the scientific merits and the business merits justify the allocation of personnel and financial resources. Patent disputes can be expensive and have led some companies into financial difficulties. Companies who have not successfully defended their patents may fall victim to patent trolls, who search for un-enforced patents in order to force companies to pay for licence fees or damage awards for the patents that they acquire. Anecdotal evidence suggests that licensing is becoming an important means of generating revenue from process innovations. Petrobank Energy and Resources Ltd. has formed its own research and development company to protect patents for its proprietary toe-to-heel air injection (THAI) oilsands recovery process, and has established a patent cooperation treaty, where patents are filed in various countries in a single procedure. However, many oil and gas companies insist that some new technologies are better protected as trade secrets. To secure a patent, a company must publicly disclose all aspects of an invention. Trade secrets are an option where secrecy can be maintained after commercialization. Unlike patent protection, which expires after 20 years, trade secrets can last indefinitely, as long as the secret is not publicly disclosed or independently developed by a competitor. While patenting may offer a competitive lead-time for some companies, many industry officials prefer to focus on using their innovations in the field. The oil and

  6. Identification by force modulation microscopy of nanoparticles generated in vacuum arcs Identification by force modulation microscopy of nanoparticles generated in vacuum arcs

    Directory of Open Access Journals (Sweden)

    M. Arroyave Franco

    2006-06-01

    Full Text Available An alternative method based on force modulation microscopy (FMM for identification of nanoparticles produced in the plasma generated by the cathode spots of vacuum arcs is presented. FMM technique is enabled for the detection of variations in the mechanical properties of a surface with high sensitiveness. Titanium nitride (TiN coatings deposited on oriented silicon by pulsed vacuum arc process have been analyzed. AFM (Atomic Force Microscopy and FMM images were simultaneously obtained, and in all cases it was possible to identify nanoparticle presence. Further X-ray Diffraction spectra of sample coating were taken. Existence of contaminant particles of 47 nanometers in diameter was reported.En este trabajo se presenta un método alternativo basado en microscopia de modulación de fuerza (FMM, para la identificación de nanogotas producidas en el plasma generado por los spots catódicos de los arcos en vacío. La técnica FMM esta habilitada para la detección de variaciones en las propiedades mecánicas de una superficie, con alta sensibilidad. Se han analizado recubrimientos de nitruro de titanio (TiN depositados sobre Silicio orientado por el proceso de arco en vacío pulsado. Se han obtenido simultáneamente imágenes de microscopia de fuerza atómica (AFM y de microscopia FMM mediante las cuales se ha podido identificar la presencia de nanogotas. Adicionalmente se han tomado espectros de difracción de rayos X (XRD de las muestras recubiertas. Se ha reportado la existencia de partículas contaminantes de 47 nanómetros de diámetro sobre los recubrimientos.

  7. Generation of random numbers on graphics processors: forced indentation in silico of the bacteriophage HK97.

    Science.gov (United States)

    Zhmurov, A; Rybnikov, K; Kholodov, Y; Barsegov, V

    2011-05-12

    The use of graphics processing units (GPUs) in simulation applications offers a significant speed gain as compared to computations on central processing units (CPUs). Many simulation methods require a large number of independent random variables generated at each step. We present two approaches for implementation of random number generators (RNGs) on a GPU. In the one-RNG-per-thread approach, one RNG produces a stream of random numbers in each thread of execution, whereas the one-RNG-for-all-threads method builds on the ability of different threads to communicate, thus, sharing random seeds across an entire GPU device. We used these approaches to implement Ran2, Hybrid Taus, and Lagged Fibonacci algorithms on a GPU. We profiled the performance of these generators in terms of the computational time, memory usage, and the speedup factor (CPU time/GPU time). These generators have been incorporated into the program for Langevin simulations of biomolecules fully implemented on the GPU. The ∼250-fold computational speedup on the GPU allowed us to carry out single-molecule dynamic force measurements in silico to explore the mechanical properties of the bacteriophage HK97 in the experimental subsecond time scale. We found that the nanomechanical response of HK97 depends on the conditions of force application, including the rate of change and geometry of the mechanical perturbation. Hence, using the GPU-based implementation of RNGs, presented here, in conjunction with Langevin simulations, makes it possible to directly compare the results of dynamic force measurements in vitro and in silico.

  8. Measuring Pushing and Braking Forces Generated by Ensembles of Kinesin-5 Crosslinking Two Microtubules.

    Science.gov (United States)

    Shimamoto, Yuta; Forth, Scott; Kapoor, Tarun M

    2015-09-28

    The proper organization of the microtubule-based mitotic spindle is proposed to depend on nanometer-sized motor proteins generating forces that scale with a micron-sized geometric feature, such as microtubule overlap length. However, it is unclear whether such regulation can be achieved by any mitotic motor protein. Here, we employ an optical-trap- and total internal reflection fluorescence (TIRF)-based assay to show that ensembles of kinesin-5, a conserved mitotic motor protein, can push apart overlapping antiparallel microtubules to generate a force whose magnitude scales with filament overlap length. We also find that kinesin-5 can produce overlap-length-dependent "brake-like" resistance against relative microtubule sliding in both parallel and antiparallel geometries, an activity that has been suggested by cell biological studies but had not been directly measured. Together, these findings, along with numerical simulations, reveal how a motor protein can function as an analog converter, "reading" simple geometric and dynamic features in cytoskeletal networks to produce regulated force outputs. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Enhancing the examiner's resisting force improves the validity of manual muscle strength measurements: application to knee extensors and flexors.

    Science.gov (United States)

    Lu, Tung-Wu; Chien, Hui-Lien; Chang, Ling-Ying; Hsu, Horng-Chaung

    2012-09-01

    The purposes of this study were to test whether an examiner's strength may affect the validity of the knee muscle strength measurements using a hand-held dynamometer (HHD) and whether enhancing the forces applied by an examiner using a resistance-enhanced dynamometer (RED) would improve measurement validity. Twenty-five young male volunteers (mean [±SD] age: 22.5 ± 1.7 years) without a history of injury to the test limb and 6 male and 6 female experienced examiners participated in this study. Maximum resisting forces of the knee flexors and extensors were measured using RED, HHD, and a dynamometer (Kin-Com). For all testing conditions, poor to moderate associations were found between the HHD and Kin-Com, whereas there was a good to excellent relationship between RED and Kin-Com. The systematic variations between RED and Kin-Com were also smaller than those between HHD and Kin-Com. The force values measured by RED were very close to those measured by Kin-Com. An examiner's strength affects the validity of the measurements using HHD. Enhancing the forces applied by the examiner to the tested segment using RED appeared to improve the validity of muscle strength measurements.

  10. Explicit polarization: a quantum mechanical framework for developing next generation force fields.

    Science.gov (United States)

    Gao, Jiali; Truhlar, Donald G; Wang, Yingjie; Mazack, Michael J M; Löffler, Patrick; Provorse, Makenzie R; Rehak, Pavel

    2014-09-16

    Conspectus Molecular mechanical force fields have been successfully used to model condensed-phase and biological systems for a half century. By means of careful parametrization, such classical force fields can be used to provide useful interpretations of experimental findings and predictions of certain properties. Yet, there is a need to further improve computational accuracy for the quantitative prediction of biomolecular interactions and to model properties that depend on the wave functions and not just the energy terms. A new strategy called explicit polarization (X-Pol) has been developed to construct the potential energy surface and wave functions for macromolecular and liquid-phase simulations on the basis of quantum mechanics rather than only using quantum mechanical results to fit analytic force fields. In this spirit, this approach is called a quantum mechanical force field (QMFF). X-Pol is a general fragment method for electronic structure calculations based on the partition of a condensed-phase or macromolecular system into subsystems ("fragments") to achieve computational efficiency. Here, intrafragment energy and the mutual electronic polarization of interfragment interactions are treated explicitly using quantum mechanics. X-Pol can be used as a general, multilevel electronic structure model for macromolecular systems, and it can also serve as a new-generation force field. As a quantum chemical model, a variational many-body (VMB) expansion approach is used to systematically improve interfragment interactions, including exchange repulsion, charge delocalization, dispersion, and other correlation energies. As a quantum mechanical force field, these energy terms are approximated by empirical functions in the spirit of conventional molecular mechanics. This Account first reviews the formulation of X-Pol, in the full variationally correct version, in the faster embedded version, and with systematic many-body improvements. We discuss illustrative examples

  11. Examining Associations between Reading Motivation and Inference Generation beyond Reading Comprehension Skill

    Science.gov (United States)

    Clinton, Virginia

    2015-01-01

    The purpose of this study was to examine the associations between reading motivation and inference generation while reading. Undergraduate participants (N = 69) read two science articles while thinking aloud, completed a standardized reading comprehension assessment, and self reported their habitual reading motivation. Findings indicate that…

  12. Technical examination and simulation of a photovoltaic system: Solar generator, battery, download

    Science.gov (United States)

    Thoma, Armin

    Examinations of each component behavior of a solar generator system are carried out. A solar tank station was supplied to an electric car on a low loss regulator. By using a large system battery, the vehicle battery could be fully loaded. Several loading processes were used for the electric car by using the system battery with an intelligent regulator. Examinations for range optimization were achieved with integration of a measure data acquisition system in the electric car. A measuring process was developed for recording the current-voltage curve of high power solar generators with low-loss load simulators. A state analysis of solar generator was obtained by comparison of data sets. A software tool was realized for analysis of operation state. By converting equivalent schemes into simulation programs, device optimization was carried out with parameter variation.

  13. Experimental study of tube/support impact forces in multi-span PWR steam generator tubes

    International Nuclear Information System (INIS)

    Axisa, F.; Desseaux, A.; Gibert, R.J.

    1984-12-01

    The vibro-impact response of a straight part of a steam generator tube is investigated experimentally and using numerical simulation with the aim to relate tube overall dynamics with excitation and tube-support clearance. Configuration studied here corresponds to the tube being excited in only one direction at its first resonance presenting an antinode of vibration at the impacted support. Tests show namely that midspan displacement of tube is almost proportional to excitation level and clearance. Impact forces averaged over a cycle of vibration are almost proportional to excitation and poorly dependent on clearance. Results of numerical simulation are in fairly good agreement with test results

  14. Analysis of Muscle Force-Velocity Parameter Changes in Elderly Women Resulting from Physical Activity--In Continuous Examinations

    Science.gov (United States)

    Skrzek, Anna; Stefanska, Malgorzata

    2012-01-01

    The aim of the paper was to evaluate changes in muscle force-velocity parameters (F-v) in elderly women subjected to physical exercise. The examinations encompassed 20 women, aged 62-71, who were students at the University of the Third Age in Wroclaw. The evaluation of flexors and extensors of the knee joint, as well as flexors and extensors of…

  15. In situ ultrasonic examination of high-strength steam generator support bolts

    International Nuclear Information System (INIS)

    Jusino, A.

    1985-01-01

    Currently employed high-strength steam generator support bolting material (designed prior to ASME Section III Part NF or Component Supports), 38.1 mm in diameter, in combination with high preloads are susceptible to stress corrosion cracking because of the relatively low stress corrosion resistance (K/sub ISCC/) properties. These bolts are part of the pressurized water reactor steam generator supports at the integral support pads (three per steam generator, with each pad housing six, eight, or ten bolts depending on the design). The US Nuclear Regulatory Commission concerns for high-strength bolting were identified in NUREG-0577, ''Potential for Low Fracture Toughness and Laminar Tearing in PWR Steam Generator and Reactor Coolant Pump Supports,'' which was issued for comment on unresolved safety issue A-12. Subsequently, the bolting issues were addressed in generic issue B29. One of the issues deals specifically with high-strength bolting materials, which are vulnerable to stress corrosion cracking. A Westinghouse Owners Group funded program was established to develop in situ ultrasonic examination techniques to determine steam generator support bolting integrity at the head-to-shank and first-thread locations. This program was established in order to determine bolting integrity in place. Ultrasonic techniques were developed for both socket-head and flat-head bolt configurations. As a result of this program, in situ ultrasonic examination techniques were developed for examination of PWR steam generator support bolts. By employing these techniques utilities will be able to ensure the integrity of this in-place bolting without incurring the costs previously experienced during removal for surface examinations

  16. Examining Evolving Performance on the Force Concept Inventory Using Factor Analysis

    Science.gov (United States)

    Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W

    2017-01-01

    The application of factor analysis to the "Force Concept Inventory" (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a…

  17. Measurement of the impuslive force generated by colapsing bubble close to a solid boundary

    Directory of Open Access Journals (Sweden)

    Zima Patrik

    2012-04-01

    Full Text Available The article presents experimental results of the acoustical and optical study of cavitation bubble collapse close to a solid boundary in water. The bubble was generated by discharge of low-voltage capacitor into a couple of wires closing a simple circuit. Different distances from the solid wall and different maximum bubble radii were studied. The bubble radius was studied using time-resolved photography and by PVDF film sensor glued on the solid boundary. The illumination was provided by high-power led diode. Synchronization of the system was provided by pulse generator connected to an oscilloscope. The impact power of the bubble to the wall was estimated from the time-resolved photography of the bubble and from the PVDF film sensor signal. The PVDF film sensor calibration was performed by a pendulum test to estimate the impact force.

  18. Entropy generation through combined non-grey gas radiation and forced convection between two parallel plates

    International Nuclear Information System (INIS)

    Ben Nejma, F.; Mazgar, A.; Abdallah, N.; Charrada, K.

    2008-01-01

    The current study presents a numerical computation of combined gas radiation and forced convection through two parallel plates. A laminar flow of a temperature-dependent and non-grey gas in the entrance region of the channel was investigated. Over-heated water vapor was chosen as a gas because of its large absorption bands. Some special attention was given to entropy generation and its dependence on geometrical and thermodynamic parameters. The radiative part of the study was solved using the 'Ray Tracing' method through S 4 directions, associated with the 'statistical narrow band correlated-k' (SNBCK) model. The temperature fields were used to calculate the distributions of local and global entropy generation

  19. Design of the magnetorheological mount with high damping force for medium speed diesel generators

    Science.gov (United States)

    Kang, O.-H.; Kim, W.-H.; Joo, W. H.; Park, J.-H.

    2013-04-01

    This paper investigates the controllable magnetorheological (MR) mount for the marine diesel-generator (D/G) sets. Sometimes, significant vibrations over the allowable limit are observed on the D/G sets due to their huge excitation forces. Because the severe vibration can lead to structural damages to the D/G sets, it should be reduced to below the limit. Although passive mounts with rubber isolators are usually used, the vibration reduction performance is not always sufficient. In addition, expecting that the vibration levels required by customers will get more severe, semi-active vibration isolation system needs to be developed. To the aim, the valve (flow) mode type of MR mount has been designed. Especially, the annular-radial configuration was adopted to enhance the damping force within the restricted space. The geometry of the mount has been optimized to obtain the required damping force and the magnetic field analysis has been carried out using ANSYS APDL. To verify the performance of the developed MR mount, excitation test was conducted and the dynamic characteristics were identified. Since damping property of the MR fluid is changed by the applied magnetic field strength and excitation frequency, responses to changing applied currents and frequencies were obtained. From the results, damping performance of the MR mount was evaluated.

  20. Easy Volcanic Aerosol (EVA v1.0: an idealized forcing generator for climate simulations

    Directory of Open Access Journals (Sweden)

    M. Toohey

    2016-11-01

    Full Text Available Stratospheric sulfate aerosols from volcanic eruptions have a significant impact on the Earth's climate. To include the effects of volcanic eruptions in climate model simulations, the Easy Volcanic Aerosol (EVA forcing generator provides stratospheric aerosol optical properties as a function of time, latitude, height, and wavelength for a given input list of volcanic eruption attributes. EVA is based on a parameterized three-box model of stratospheric transport and simple scaling relationships used to derive mid-visible (550 nm aerosol optical depth and aerosol effective radius from stratospheric sulfate mass. Precalculated look-up tables computed from Mie theory are used to produce wavelength-dependent aerosol extinction, single scattering albedo, and scattering asymmetry factor values. The structural form of EVA and the tuning of its parameters are chosen to produce best agreement with the satellite-based reconstruction of stratospheric aerosol properties following the 1991 Pinatubo eruption, and with prior millennial-timescale forcing reconstructions, including the 1815 eruption of Tambora. EVA can be used to produce volcanic forcing for climate models which is based on recent observations and physical understanding but internally self-consistent over any timescale of choice. In addition, EVA is constructed so as to allow for easy modification of different aspects of aerosol properties, in order to be used in model experiments to help advance understanding of what aspects of the volcanic aerosol are important for the climate system.

  1. Generating Converged Accurate Free Energy Surfaces for Chemical Reactions with a Force-Matched Semiempirical Model.

    Science.gov (United States)

    Kroonblawd, Matthew P; Pietrucci, Fabio; Saitta, Antonino Marco; Goldman, Nir

    2018-03-22

    We demonstrate the capability of creating robust density functional tight binding (DFTB) models for chemical reactivity in prebiotic mixtures through force matching to short time scale quantum free energy estimates. Molecular dynamics using density functional theory (DFT) is a highly accurate approach to generate free energy surfaces for chemical reactions, but the extreme computational cost often limits the time scales and range of thermodynamic states that can feasibly be studied. In contrast, DFTB is a semiempirical quantum method that affords up to a thousandfold reduction in cost and can recover DFT-level accuracy. Here, we show that a force-matched DFTB model for aqueous glycine condensation reactions yields free energy surfaces that are consistent with experimental observations of reaction energetics. Convergence analysis reveals that multiple nanoseconds of combined trajectory are needed to reach a steady-fluctuating free energy estimate for glycine condensation. Predictive accuracy of force-matched DFTB is demonstrated by direct comparison to DFT, with the two approaches yielding surfaces with large regions that differ by only a few kcal mol -1 .

  2. Generating of additional force terms in Newton equation by twist-deformed Hopf algebras and classical symmetries

    OpenAIRE

    Daszkiewicz, Marcin

    2012-01-01

    We compare two ways of force terms generating in the model of nonrelativistic particle moving in the presence of constant field force $\\vec{F}$. First of them uses the twist-deformed acceleration-enlarged Newton-Hooke quantum space-times while the second one incorporates the doubly enlarged Newton-Hooke transformations of classical space. Particulary, we find the conditions for which the both treatments provide the same force terms.

  3. Examining aging sexual stigma attitudes among adults by gender, age, and generational status.

    Science.gov (United States)

    Syme, Maggie L; Cohn, Tracy J

    2016-01-01

    Stigma related to later life sexuality could produce detrimental effects for older adults, through individual concerns and limited sexual health care for older adults. Identifying groups at risk for aging sexual stigma will help to focus interventions to reduce it. Accordingly, the purpose of this study was to examine cross-sectional trends in aging sexual stigma attitudes by age group, generational status, and gender. An online survey was administered to a national sample of adults via a crowdsourcing tool, in order to examine aging sexual stigma across age groups, generational status, and gender (N = 962; 47.0% male, 52.5% female, and .5% other; mean age = 45 years). An aging sexual stigma index was formulated from the attitudinal items of the Aging Sexual Knowledge and Attitudes Scale. This sample reported moderately permissive attitudes toward aging sexuality, indicating a low level of aging sexual stigma. Though descriptive data showed trends of stigma attitudes increasing with age and later generations, there were no significant differences between age groups or generations in terms of aging sexual stigma beliefs. Men, regardless of age and/or generation, were found to espouse significantly higher stigmatic beliefs than women or those reporting 'other' gender. Aging sexual stigma beliefs may not be prevalent among the general population as cohorts become more sexually liberal over time, though men appear more susceptible to these beliefs. However, in order to more comprehensively assess aging sexual stigma, future research may benefit from measuring explicit and implicit aging sexual stigma beliefs.

  4. Conserved mechanisms of microtubule-stimulated ADP release, ATP binding, and force generation in transport kinesins.

    Science.gov (United States)

    Atherton, Joseph; Farabella, Irene; Yu, I-Mei; Rosenfeld, Steven S; Houdusse, Anne; Topf, Maya; Moores, Carolyn A

    2014-09-10

    Kinesins are a superfamily of microtubule-based ATP-powered motors, important for multiple, essential cellular functions. How microtubule binding stimulates their ATPase and controls force generation is not understood. To address this fundamental question, we visualized microtubule-bound kinesin-1 and kinesin-3 motor domains at multiple steps in their ATPase cycles--including their nucleotide-free states--at ∼ 7 Å resolution using cryo-electron microscopy. In both motors, microtubule binding promotes ordered conformations of conserved loops that stimulate ADP release, enhance microtubule affinity and prime the catalytic site for ATP binding. ATP binding causes only small shifts of these nucleotide-coordinating loops but induces large conformational changes elsewhere that allow force generation and neck linker docking towards the microtubule plus end. Family-specific differences across the kinesin-microtubule interface account for the distinctive properties of each motor. Our data thus provide evidence for a conserved ATP-driven mechanism for kinesins and reveal the critical mechanistic contribution of the microtubule interface.

  5. Experimental and theoretical analysis of a hybrid solar thermoelectric generator with forced convection cooling

    Science.gov (United States)

    Sundarraj, Pradeepkumar; Taylor, Robert A.; Banerjee, Debosmita; Maity, Dipak; Sinha Roy, Susanta

    2017-01-01

    Hybrid solar thermoelectric generators (HSTEGs) have garnered significant research attention recently due to their potential ability to cogenerate heat and electricity. In this paper, theoretical and experimental investigations of the electrical and thermal performance of a HSTEG system are reported. In order to validate the theoretical model, a laboratory scale HSTEG system (based on forced convection cooling) is developed. The HSTEG consists of six thermoelectric generator modules, an electrical heater, and a stainless steel cooling block. Our experimental analysis shows that the HSTEG is capable of producing a maximum electrical power output of 4.7 W, an electrical efficiency of 1.2% and thermal efficiency of 61% for an average temperature difference of 92 °C across the TEG modules with a heater power input of 382 W. These experimental results of the HSTEG system are found to be in good agreement with the theoretical prediction. This experimental/theoretical analysis can also serve as a guide for evaluating the performance of the HSTEG system with forced convection cooling.

  6. Myostatin dysfunction impairs force generation in extensor digitorum longus muscle and increases exercise-induced protein efflux from extensor digitorum longus and soleus muscles.

    Science.gov (United States)

    Baltusnikas, Juozas; Kilikevicius, Audrius; Venckunas, Tomas; Fokin, Andrej; Bünger, Lutz; Lionikas, Arimantas; Ratkevicius, Aivaras

    2015-08-01

    Myostatin dysfunction promotes muscle hypertrophy, which can complicate assessment of muscle properties. We examined force generating capacity and creatine kinase (CK) efflux from skeletal muscles of young mice before they reach adult body and muscle size. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of Berlin high (BEH) mice with dysfunctional myostatin, i.e., homozygous for inactivating myostatin mutation, and with a wild-type myostatin (BEH+/+) were studied. The muscles of BEH mice showed faster (P < 0.01) twitch and tetanus contraction times compared with BEH+/+ mice, but only EDL displayed lower (P < 0.05) specific force. SOL and EDL of age-matched but not younger BEH mice showed greater exercise-induced CK efflux compared with BEH+/+ mice. In summary, myostatin dysfunction leads to impairment in muscle force generating capacity in EDL and increases susceptibility of SOL and EDL to protein loss after exercise.

  7. WIND TUNNEL RESEARCH ON THE INFLUENCE OF ACTIVE AIRFLOW ON THE LIFT FORCE GENERATED BY THE AIRFOIL

    Directory of Open Access Journals (Sweden)

    Paweł Magryta

    2013-09-01

    Full Text Available The paper discusses the results of wind tunnel tests of airfoils with additional active airflow applied to their upper surfaces. These studies were carried out for a range of velocities up to 28 m/s in an open wind tunnel. Several types of airfoils selected for the examination feature different geometries and are widely applied in today’s aviation industry. The changes in the lift and drag force generated by these airfoils were recorded during the study. The test bench for the tests was equipped with a compressor and a vacuum pump to enable airflow through some holes on the airfoil upper surface. A rapid prototyping method and a 3D printer based on a powder printing technique were applied to print the airfoils. All of their surfaces were subject to surface grinding to smooth their external surfaces. The wind tunnel tests with and without active airflow applied to airfoils are summarised in the paper.

  8. Age differences in volunteering experiences: an examination of generativity and meaning in life

    OpenAIRE

    Fyffe, Ian Alexander

    2012-01-01

    The purpose of this thesis is to examine differences in volunteering experiences between middle-aged and older aged persons participating in the 2010 Vancouver Winter Olympics. Erik Erikson’s (1959/1994) concept of generativity is applied in order to test hypotheses pertaining to age-related associations between a pre-existing community volunteer role and meaning, self-esteem and meaning as well as sense of belonging and meaning. Data were utilized from the Older Olympic Volunteer Project ...

  9. Perceived Entitlement among Amillenials versus Baby Boomers: A Cross-Generational Examination

    OpenAIRE

    Comer, Eliza

    2017-01-01

    As the Millennial workforce grows, understanding how Millennials are viewed- specifically in terms of entitlement-is an issue that merits attention, since perceived entitlement could negatively impact the extent to which an individual's contributions are valued in the workplace. While prior research suggests that Millennials are entitled (Allen 2015; Fisk 2010; Myers 2010), it neglects how perceptions of entitlement may differ across generations. We aim to address this gap by examining whethe...

  10. Measurement of hydrodynamic force generation by swimming dolphins using bubble DPIV.

    Science.gov (United States)

    Fish, Frank E; Legac, Paul; Williams, Terrie M; Wei, Timothy

    2014-01-15

    Attempts to measure the propulsive forces produced by swimming dolphins have been limited. Previous uses of computational hydrodynamic models and gliding experiments have provided estimates of thrust production by dolphins, but these were indirect tests that relied on various assumptions. The thrust produced by two actively swimming bottlenose dolphins (Tursiops truncatus) was directly measured using digital particle image velocimetry (DPIV). For dolphins swimming in a large outdoor pool, the DPIV method used illuminated microbubbles that were generated in a narrow sheet from a finely porous hose and a compressed air source. The movement of the bubbles was tracked with a high-speed video camera. Dolphins swam at speeds of 0.7 to 3.4 m s(-1) within the bubble sheet oriented along the midsagittal plane of the animal. The wake of the dolphin was visualized as the microbubbles were displaced because of the action of the propulsive flukes and jet flow. The oscillations of the dolphin flukes were shown to generate strong vortices in the wake. Thrust production was measured from the vortex strength through the Kutta-Joukowski theorem of aerodynamics. The dolphins generated up to 700 N during small amplitude swimming and up to 1468 N during large amplitude starts. The results of this study demonstrated that bubble DPIV can be used effectively to measure the thrust produced by large-bodied dolphins.

  11. Spontaneous Generation of Electromotive Force in Thin Film Al/Nanosilicon/Al Structures

    Directory of Open Access Journals (Sweden)

    Sergey G. Dorofeev

    2017-10-01

    Full Text Available Contemporary pursuits in electronics include the miniaturization as well as flexibilization of devices. Although there are a large number of different thin and flexible electrochemical batteries, only a few can boast the possibility of working in high humidity conditions. This paper reports on the fabrication of structures consisting of films of silicon nanoparticles encased between two aluminium electrodes. The value of electromotive force (emf measured depends on the temperature of the sample and on the pressure of water vapor in the storage atmosphere and reaches approximately 1 V. Volt-ampere characteristics were investigated at different conditions to yield a model of emf generation in these structures. It was found that the reaction of water with silicon nanoparticles is the prime reason behind emf generation. Such a source may be introduced into electronic paper, and employed in the next generation of smart cards. The structure may also be manufactured directly on the surface of silicon chips, such as on the back of crystals in microschemes.

  12. An Examination of Information Technology Valuation Models for the Air Force

    National Research Council Canada - National Science Library

    Peachey, Todd

    1998-01-01

    .... This thesis is designed to examine models that are currently being used in the public and private sector of the economy to evaluate Information Technology investments to learn which ones might serve...

  13. Atomic Force Microscope nanolithography on chromosomes to generate single-cell genetic probes.

    Science.gov (United States)

    Di Bucchianico, Sebastiano; Poma, Anna M; Giardi, Maria F; Di Leandro, Luana; Valle, Francesco; Biscarini, Fabio; Botti, Dario

    2011-06-28

    Chromosomal dissection provides a direct advance for isolating DNA from cytogenetically recognizable region to generate genetic probes for fluorescence in situ hybridization, a technique that became very common in cyto and molecular genetics research and diagnostics. Several reports describing microdissection methods (glass needle or a laser beam) to obtain specific probes from metaphase chromosomes are available. Several limitations are imposed by the traditional methods of dissection as the need for a large number of chromosomes for the production of a probe. In addition, the conventional methods are not suitable for single chromosome analysis, because of the relatively big size of the microneedles. Consequently new dissection techniques are essential for advanced research on chromosomes at the nanoscale level. We report the use of Atomic Force Microscope (AFM) as a tool for nanomanipulation of single chromosomes to generate individual cell specific genetic probes. Besides new methods towards a better nanodissection, this work is focused on the combination of molecular and nanomanipulation techniques which enable both nanodissection and amplification of chromosomal and chromatidic DNA. Cross-sectional analysis of the dissected chromosomes reveals 20 nm and 40 nm deep cuts. Isolated single chromosomal regions can be directly amplified and labeled by the Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP-PCR) and subsequently hybridized to chromosomes and interphasic nuclei. Atomic force microscope can be easily used to visualize and to manipulate biological material with high resolution and accuracy. The fluorescence in situ hybridization (FISH) performed with the DOP-PCR products as test probes has been tested succesfully in avian microchromosomes and interphasic nuclei. Chromosome nanolithography, with a resolution beyond the resolution limit of light microscopy, could be useful to the construction of chromosome band libraries and to the molecular

  14. Demonstration of Security Benefits of Renewable Generation at FE Warren Air Force Base

    International Nuclear Information System (INIS)

    Warwick, William M.; Myers, Kurt; Seifert, Gary

    2010-01-01

    Report detailing field demonstration of security benefits of renewable generation at FE Warren Air Force Base. The 2006 National Defense Appropriations Act directed the Department of Defense (DOD) to coordinate the testing of a wind turbine (new to the U.S. market) at an Air Force installation as a follow on to analyses conducted by the Pacific Northwest National Laborabory (PNNL) as part of the 2005 DOD Renewable Assessment. The earlier study simulated the performance of renewable power produced from wind turbines, solar photovoltaics and geothermal energy as part of a Base-wide energy security solution. The simulation concluded that integration of renewable generating resources with emergency generators, typically diesel-fired, could significantly enhance energy security and extend power supplies during prolonged commercial grid power outages. A simulation is insufficient to convince skeptics of the reliability of renewable resources, especially those that produce power only intermittently, like wind and solar. Therefore, Congress requested a field demonstration be performed using a wind turbine because wind power is the most erratic of all renewable resources. Following this direction, the Air Force identified a site for the wind turbine demonstration and contracted with the Idaho National Laboratory (INL) and PNNL to conduct the demonstration and implement other provisions in the appropriation bill. INL identified a wind turbine that met the legislative requirements (the Gamesa G-80), and with the support of PNNL and the Air Force, selected FE Warren Air Force Base for the demonstration. FE Warren has an excellent wind resource and was already a host to two wind turbines and could accommodate a third. The G-80 is rated at 2 MWs versus the two existing 660 kW turbines, consequently wind production would more than double. Procurement, siting, and acceptance testing of the new turbine was completed in early 2010. The field test was conducted in late April 2010

  15. Phase Aberration and Attenuation Effects on Acoustic Radiation Force-Based Shear Wave Generation

    Science.gov (United States)

    Amador, Carolina; Aristizabal, Sara; Greenleaf, James F.; Urban, Matthew W.

    2016-01-01

    Tissue elasticity is measured by shear wave elasticity imaging methods using acoustic radiation force to create the shear waves. Phase aberration and tissue attenuation can hamper the generation of shear waves for in vivo applications. In this study effects of phase aberration and attenuation in ultrasound focusing for creating shear waves were explored. This includes the effects of phase shifts and amplitude attenuation on shear wave characteristics such as shear wave amplitude, shear wave speed, shear wave center frequency and bandwidth. Two samples of swine belly tissue were used to create phase aberration and attenuation experimentally. To explore the phase aberration and attenuation effects individually, tissue experiments were complemented with ultrasound beam simulations using FOCUS and shear wave simulations using Finite Element Model (FEM) analysis. The ultrasound frequency used to generate shear waves was varied from 3.0 to 4.5 MHz. Results The measured acoustic pressure and resulting shear wave amplitude decreased approximately 40% to 90% with the introduction of the tissue samples. Acoustic intensity and shear wave displacement were correlated for both tissue samples, the resulting Pearson’s correlation coefficients were 0.99 and 0.97. Analysis of shear wave generation with tissue samples (Phase Aberration and Attenuation case), measured phase screen (Only Phase Aberration case) and FOCUS/FEM model (Only Attenuation case) showed that tissue attenuation affected the shear wave generation more than tissue aberration. Decreasing the ultrasound frequency helped maintain a focused beam for creation of shear waves in the presence of both phase aberration and attenuation. PMID:26742131

  16. Ca2+-activated force-generating properties of mammalian skeletal muscle fibres: histochemically identified single peeled rabbit fibres.

    Science.gov (United States)

    Donaldson, S K

    1984-12-01

    Single peeled (sarcolemma removed) rabbit skeletal muscle fibres, identified histochemically from their myofibrillar ATPase and oxidative staining patterns, were characterized according to their Ca2+-activated steady-state force-generating properties at normal intracellular pH (7.0) and under acidotic (pH 6.5) conditions. Maximum force-generating capacity of each fibre was assessed by measuring steady-state isometric force generation at saturating Ca2+ concentration at both pH values. The Ca2+ sensitivity of each fibre was ascertained by determining the percentage of maximum force generated at each of several subsaturating Ca2+ concentrations at both pH values. Fibres were selected from soleus, tibialis anterior and adductor magnus muscles. At subsaturating Ca2+ concentrations only two functional groups of fibres were distinguishable, corresponding to the histochemical classifications type I and type II. Type I fibres were more sensitive to Ca2+ and less depressed by acidosis than type II fibres in the subsaturating range of Ca2+ concentrations. At saturating Ca2+ concentrations, the acidotic depression of maximum force was significantly less for type I fibres than type II nonoxidative fibres regardless of their muscle of origin. Type II oxidative fibre maximum force properties depended upon the muscle of origin and demonstrated subgroups of these fibres that were different from type II nonoxidative fibres and similar to type I fibres.

  17. Numerical study of forced convection in a vertical channel filled with heat-generating porous medium

    International Nuclear Information System (INIS)

    Yang Jian; Zeng Min; Wang Qiuwang; Yan Xiao

    2009-01-01

    Steady laminar non-Darcian forced convection in a vertical channel filled with heat-generating porous medium is studied numerically by using the local thermal non-equilibrium model. The heat source generated by solid framework is uniform and kept constant; and the temperature of vertical walls is kept at constant temperature T 0 . The flow inside porous medium is modelled by using Forchheimer-Brinkman extended Darcy model. The effects of Reynolds number (0.5 ≤Re ≤ 50), effective fluid-to-solid thermal conductivity ratio Γ(0.001 ≤ Γ ≤ 1.0)and Darcy number (10 -3 ≤ Da ≤ 10 -5 ) are analyzed in detail. It is found that, the effects of Re, Γ and Da are remarkable; at low values of Re and Γ, and at high value of Da, the effect of local thermal non-equilibrium is significant and the local thermal non-equilibrium model should be adopted for predicting the heat transfer characteristics exactly. (authors)

  18. Computational model to investigate the relative contributions of different neuromuscular properties of tibialis anterior on force generated during ankle dorsiflexion.

    Science.gov (United States)

    Siddiqi, Ariba; Poosapadi Arjunan, Sridhar; Kumar, Dinesh Kant

    2018-01-16

    This study describes a new model of the force generated by tibialis anterior muscle with three new features: single-fiber action potential, twitch force, and pennation angle. This model was used to investigate the relative effects and interaction of ten age-associated neuromuscular parameters. Regression analysis (significance level of 0.05) between the neuromuscular properties and corresponding simulated force produced at the footplate was performed. Standardized slope coefficients were computed to rank the effect of the parameters. The results show that reduction in the average firing rate is the reason for the sharp decline in the force and other factors, such as number of muscle fibers, specific force, pennation angle, and innervation ratio. The fast fiber ratio affects the simulated force through two significant interactions. This study has ranked the individual contributions of the neuromuscular factors to muscle strength decline of the TA and identified firing rate decline as the biggest cause followed by decrease in muscle fiber number and specific force. The strategy for strength preservation for the elderly should focus on improving firing rate. Graphical abstract Neuromuscular properties of Tibialis Anterior on force generated during ankle dorsiflexion.

  19. An Adaptive Neuro-Fuzzy Inference System for Sea Level Prediction Considering Tide-Generating Forces and Oceanic Thermal Expansion

    Directory of Open Access Journals (Sweden)

    Li-Ching Lin Hsien-Kuo Chang

    2008-01-01

    Full Text Available The paper presents an adaptive neuro fuzzy inference system for predicting sea level considering tide-generating forces and oceanic thermal expansion assuming a model of sea level dependence on sea surface temperature. The proposed model named TGFT-FN (Tide-Generating Forces considering sea surface Temperature and Fuzzy Neuro-network system is applied to predict tides at five tide gauge sites located in Taiwan and has the root mean square of error of about 7.3 - 15.0 cm. The capability of TGFT-FN model is superior in sea level prediction than the previous TGF-NN model developed by Chang and Lin (2006 that considers the tide-generating forces only. The TGFT-FN model is employed to train and predict the sea level of Hua-Lien station, and is also appropriate for the same prediction at the tide gauge sites next to Hua-Lien station.

  20. Fiber Fabry-Perot Force Sensor with Small Volume and High Performance for Assessing Fretting Damage of Steam Generator Tubes.

    Science.gov (United States)

    Huang, Peijian; Wang, Ning; Li, Junying; Zhu, Yong; Zhang, Jie

    2017-12-13

    Measuring the radial collision force between the steam generator tube (SGT) and the tube support plate (TSP) is essential to assess the fretting damage of the SGT. In order to measure the radial collision force, a novel miniaturized force sensor based on fiber Fabry-Perot (F-P) was designed, and the principle and characteristics of the sensor were analyzed in detail. Then, the F-P force sensor was successfully fabricated and calibrated, and the overall dimensions of the encapsulated fiber F-P sensor were 17 mm × 5 mm × 3 mm (L × W × H). The sensor works well in humid, high pressure (10 MPa), high temperature (350 °C), and vibration (40 kHz) environments. Finally, the F-P force sensors were installed in a 1:1 steam generator test loop, and the radial collision force signals between the SGT and the TSP were obtained. The experiments indicated that the F-P sensor with small volume and high performance could help in assessing the fretting damage of the steam generator tubes.

  1. Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents.

    Science.gov (United States)

    Ballak, Sam B; Degens, Hans; de Haan, Arnold; Jaspers, Richard T

    2014-03-01

    Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Characterization of the photocurrents generated by the laser of atomic force microscopes.

    Science.gov (United States)

    Ji, Yanfeng; Hui, Fei; Shi, Yuanyuan; Iglesias, Vanessa; Lewis, David; Niu, Jiebin; Long, Shibing; Liu, Ming; Hofer, Alexander; Frammelsberger, Werner; Benstetter, Guenther; Scheuermann, Andrew; McIntyre, Paul C; Lanza, Mario

    2016-08-01

    The conductive atomic force microscope (CAFM) has become an essential tool for the nanoscale electronic characterization of many materials and devices. When studying photoactive samples, the laser used by the CAFM to detect the deflection of the cantilever can generate photocurrents that perturb the current signals collected, leading to unreliable characterization. In metal-coated semiconductor samples, this problem is further aggravated, and large currents above the nanometer range can be observed even without the application of any bias. Here we present the first characterization of the photocurrents introduced by the laser of the CAFM, and we quantify the amount of light arriving to the surface of the sample. The mechanisms for current collection when placing the CAFM tip on metal-coated photoactive samples are also analyzed in-depth. Finally, we successfully avoided the laser-induced perturbations using a two pass technique: the first scan collects the topography (laser ON) and the second collects the current (laser OFF). We also demonstrate that CAFMs without a laser (using a tuning fork for detecting the deflection of the tip) do not have this problem.

  3. LITERATURE REVIEW OF ELECTROMAGNETIC ACTUATOR FORCE GENERATION FOR DYNAMIC MODAL TESTING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Norlida Jamil

    2012-12-01

    Full Text Available Milling is one of the most common manufacturing processes for automotive components, but its productivity is limited by the onset of regenerative chatter. This is a form of unstable self-excited vibration that occurs when the volume of material removed is too large for a particular spindle speed. This form of chatter is undesirable because it results in premature tool wear, poor surface finish on the machined component and the possibility of serious damage to the machine itself. The chatter stability of a milling process can be determined using well-established theory, provided that the frequency response of the flexible structure can be determined. In practice this usually involves the excitation of a stationery (non-rotating milling tool with a modal hammer, and measurement of the response of the tool with a co-located accelerometer. However, this measurement is not necessarily accurate due to amplitude dependency factor consideration. There is anecdotal evidence that structural nonlinearity can have a significant effect on the chatter stability of some milling machines. This project develops non-contact electromagnetic actuators to measure the frequency response of milling tools to machine automotive parts. In addition it will describe the practical application of this approach, and discuss its amplitude dependency for current excitation during frequency response function measurement using magnetic force generation.

  4. Examination of Force Discrimination in Human Upper Limb Amputees With Reinnervated Limb Sensation Following Peripheral Nerve Transfer

    Science.gov (United States)

    Sensinger, Jonathon W.; Schultz, Aimee E.; Kuiken, Todd A.

    2011-01-01

    Artificial limbs allow amputees to manipulate objects, but the loss of a limb severs the sensory link between a subject and objects they touch. A novel surgical technique we term targeted reinnervation (TR) allows severed cutaneous nerves to reinnervate skin on a different portion of the body. This technique provides a physiologically appropriate portal to the sensory pathways of the missing limb through the reinnervated skin. This study quantified the ability of three amputee subjects who had undergone TR surgery on the chest (two subjects) and upper arm (one subject) to discriminate changes in graded force on their reinnervated skin over a range of 1–4 N using a stochastic staircase approach. These values were compared to those from sites on their intact contralateral skin and index fingers, and from the chests and index fingers of a control population (n = 10). Weber’s ratio (WR) was used to examine the subjects’ abilities to discriminate between a baseline force and subsequent forces of different magnitudes. WRs of 0.22, 0.25, and 0.12 were measured on the reinnervated skin of the three TR subjects, whereas WRs of 0.25,0.23, and 0.12 were measured on their contralateral skin. TR subjects did not have substantially different WRs on their reinnervated versus their contralateral normal side and did not appear to exhibit a trend towards impaired sensation. No significant difference was found between the WR of the chest and index finger of the control subjects, which ranged between 0.09 and 0.21. WR of reinnervated skin for TR subjects were within the 95% confidence interval of the control group. These data suggest that subjects with targeted reinnervation have unimpaired ability to discriminate gradations in force. PMID:19775983

  5. Preanalytics of urine sediment examination: effect of relative centrifugal force, tube type, volume of sample and supernatant removal.

    Science.gov (United States)

    Bunjevac, Amalija; Gabaj, Nora Nikolac; Miler, Marijana; Horvat, Anita

    2018-02-15

    Laboratories often modify procedures recommended by the European Urinalysis Guidelines for urine sediment analysis. The aim of this study was to compare the recommended protocol with our routine laboratory procedure and to evaluate the possible impact of modifications in the relative centrifugal force, type of tube, method of supernatant aspiration and urine volume on patient's results. Firstly, relative centrifugal force was investigated using 20 pairs of samples examined after centrifugation at 400xg and 1358xg. In phase two, 110 samples were examined, paired as: round bottom vs conical tube (N = 46), decanting vs suction of supernatant (N = 100) and 10 mL vs 5 mL of urine sample (N = 101). The number of erythrocytes, leukocytes and squamous epithelial cells was significantly lower after centrifugation at 400xg (P = 0.001, 0.002 and 0.004, respectively). The number of leukocytes was significantly lower in conical tubes (P = 0.010), after the suction of supernatant (P = 0.045) and in 5 mL urine (P urine (P urine. Lower results of leukocytes, erythrocytes, squamous cells and non-hyaline casts were recorded in recommended procedures (centrifugation at 400xg, suction of supernatant, conical tube, 5 mL of sample) than in routine procedure (centrifugation at 1358xg, decanting of supernatant, round bottom tube, 10 mL) used in our laboratory.

  6. A Preliminary Examination of the Second Generation CMORPH Real-time Production

    Science.gov (United States)

    Joyce, R.; Xie, P.; Wu, S.

    2017-12-01

    The second generation CMORPH (CMORPH2) has started test real-time production of 30-minute precipitation estimates on a 0.05olat/lon grid over the entire globe, from pole-to-pole. The CMORPH2 is built upon the Kalman Filter based CMORPH algorithm of Joyce and Xie (2011). Inputs to the system include rainfall and snowfall rate retrievals from passive microwave (PMW) measurements aboard all available low earth orbit (LEO) satellites, precipitation estimates derived from infrared (IR) observations of geostationary (GEO) and LEO platforms, and precipitation simulations from the NCEP operational global forecast system (GFS). Inputs from the various sources are first inter-calibrated to ensure quantitative consistencies in representing precipitation events of different intensities through PDF calibration against a common reference standard. The inter-calibrated PMW retrievals and IR-based precipitation estimates are then propagated from their respective observation times to the target analysis time along the motion vectors of the precipitating clouds. Motion vectors are first derived separately from the satellite IR based precipitation estimates and the GFS precipitation fields. These individually derived motion vectors are then combined through a 2D-VAR technique to form an analyzed field of cloud motion vectors over the entire globe. The propagated PMW and IR based precipitation estimates are finally integrated into a single field of global precipitation through the Kalman Filter framework. A set of procedures have been established to examine the performance of the CMORPH2 real-time production. CMORPH2 satellite precipitation estimates are compared against the CPC daily gauge analysis, Stage IV radar precipitation over the CONUS, and numerical model forecasts to discover potential shortcomings and quantify improvements against the first generation CMORPH. Special attention has been focused on the CMORPH behavior over high-latitude areas beyond the coverage of the first

  7. Examination of steam generator alloy 800 NG tube from the Almaraz unit 2 NPP

    International Nuclear Information System (INIS)

    Diego, G. de; Gomez Briceno, D.; Maffiotte, C.; Baladia, M.; Arias, C.J.

    2015-01-01

    The steam generators of Almaraz Unit 2 were replaced in 1997 by the model 61W/D3 (Siemens) with Alloy 800NG steam generator tubes. Denting indications were firstly detected in 2006 in the SG-3. Crack indications were identified in 2009. At the end of 2011, three tubes were recovered from this steam generator to carry out destructive examination in order to identify the root cause of the tubes degradation. Analysis of deposits point out the existence of multiples elements in the removed OD (Outer Diameter) deposits as well as in the deposits at the free tube under sludge and at the transition zone. Deposits are more abundant at the transition zone than at free tube. About 10% Na concentration has been detected, whereas S and Cl appear in small concentrations. Si appears regularly and Cr, Ni concentrations in the deposits are similar. Multiple intergranular cracks have been detected at 3 mm above the last contact point between the tube and the TS (tube support), in a band of around 5 mm, practically in the whole perimeter of the tube. Fracture surface of crack-B was partially covered by a Si rich layer, whereas fracture surface of crack-A seems to be cleaner. However, no significant differences in composition, except higher amount of S in crack-B, were found in the deposits of both cracks. EDX mapping and Auger profiles point out Ni enrichment with slight Cr enrichment or depletion and Fe depletion. The comparison of Auger profiles with available results for Alloy 800 tested in caustic and acid sulfate environments seems to indicate that the environment inside the cracks detected in the tube R67C48 is neutral or moderately caustic

  8. Integrated Analysis of Contractile Kinetics, Force Generation, and Electrical Activity in Single Human Stem Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Jan David Kijlstra

    2015-12-01

    Full Text Available The quantitative analysis of cardiomyocyte function is essential for stem cell-based approaches for the in vitro study of human cardiac physiology and pathophysiology. We present a method to comprehensively assess the function of single human pluripotent stem cell-derived cardiomyocyte (hPSC-CMs through simultaneous quantitative analysis of contraction kinetics, force generation, and electrical activity. We demonstrate that statistical analysis of movies of contracting hPSC-CMs can be used to quantify changes in cellular morphology over time and compute contractile kinetics. Using a biomechanical model that incorporates substrate stiffness, we calculate cardiomyocyte force generation at single-cell resolution and validate this approach with conventional traction force microscopy. The addition of fluorescent calcium indicators or membrane potential dyes allows the simultaneous analysis of contractility and calcium handling or action potential morphology. Accordingly, our approach has the potential for broad application in the study of cardiac disease, drug discovery, and cardiotoxicity screening.

  9. Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics

    Directory of Open Access Journals (Sweden)

    Roberta Ferreira Pimentel

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu and one type of sapphire monocrystalline bracket (Radiance in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets. METHODS: Tests were performed in dry and artificial saliva wet setting (Oral Balance by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in brackets (n = 18 for each bracket. In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. RESULTS: The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coefficients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artificial saliva, the Radiance and the 20/40 brackets had statistically similar friction coefficients and both were greater than that presented by the InVu brackets. The artificial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu, an increase of friction was observed in its presence. CONCLUSION: The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coefficient.OBJETIVO: avaliar e comparar in vitro as cargas máximas de atrito geradas por três tipos de braquetes estéticos, sendo dois deles cerâmicos policristalinos convencionais (20/40 e InVu e um monocristalino de safira (Radiance, em ambientes seco e umedecido por saliva artificial. Também avaliar a influência exercida pela saliva artificial sobre as cargas de atrito dos referidos

  10. Eccentric Contraction-Induced Muscle Injury: Reproducible, Quantitative, Physiological Models to Impair Skeletal Muscle’s Capacity to Generate Force

    Science.gov (United States)

    Call, Jarrod A.; Lowe, Dawn A.

    2018-01-01

    In order to investigate the molecular and cellular mechanisms of muscle regeneration an experimental injury model is required. Advantages of eccentric contraction-induced injury are that it is a controllable, reproducible, and physiologically relevant model to cause muscle injury, with injury being defined as a loss of force generating capacity. While eccentric contractions can be incorporated into conscious animal study designs such as downhill treadmill running, electrophysiological approaches to elicit eccentric contractions and examine muscle contractility, for example before and after the injurious eccentric contractions, allows researchers to circumvent common issues in determining muscle function in a conscious animal (e.g., unwillingness to participate). Herein, we describe in vitro and in vivo methods that are reliable, repeatable, and truly maximal because the muscle contractions are evoked in a controlled, quantifiable manner independent of subject motivation. Both methods can be used to initiate eccentric contraction-induced injury and are suitable for monitoring functional muscle regeneration hours to days to weeks post-injury. PMID:27492161

  11. Eccentric Contraction-Induced Muscle Injury: Reproducible, Quantitative, Physiological Models to Impair Skeletal Muscle's Capacity to Generate Force.

    Science.gov (United States)

    Call, Jarrod A; Lowe, Dawn A

    2016-01-01

    In order to investigate the molecular and cellular mechanisms of muscle regeneration an experimental injury model is required. Advantages of eccentric contraction-induced injury are that it is a controllable, reproducible, and physiologically relevant model to cause muscle injury, with injury being defined as a loss of force generating capacity. While eccentric contractions can be incorporated into conscious animal study designs such as downhill treadmill running, electrophysiological approaches to elicit eccentric contractions and examine muscle contractility, for example before and after the injurious eccentric contractions, allows researchers to circumvent common issues in determining muscle function in a conscious animal (e.g., unwillingness to participate). Herein, we describe in vitro and in vivo methods that are reliable, repeatable, and truly maximal because the muscle contractions are evoked in a controlled, quantifiable manner independent of subject motivation. Both methods can be used to initiate eccentric contraction-induced injury and are suitable for monitoring functional muscle regeneration hours to days to weeks post-injury.

  12. Investigation of a potential force-generation machinery driven by a cytoskeletal Walker-type ATPase in prokaryotic cells

    Science.gov (United States)

    Erbe, Andeas; Hou, Sing-Yi; Chen, Chen-Yun; Lin, Yi-Lih; Shen, Jie-Pan; Lin, Li-Jing; Chou, Chia-Fu; Shih, Yu-Ling

    2008-03-01

    Cytoskeletal proteins are often involved in generating mechanical force to drive various cellular processes. A subgroup of the Walker-type ATPases acts as cytoskeletal proteins that show highly dynamic behavior in bacterial cells. One of the most prominent examples is MinD that works with other cellular components to prevent cell division at unwanted polar sites through cycles of pole-to-pole oscillation in E. coli cells. We use fluorescence microscopy techniques to study the process of MinD assembly and disassembly on a lipid bilayer membrane surface and any possible change of membrane properties caused by MinD association with the membrane. To form a supported bilayer membrane, vesicles of the polar or total extract of E. coli membrane or synthetic lipids of defined composition are adsorbed to a treated glass coverslip. Ca^2+ is added to enable vesicle fusion to form a continuous bilayer on a glass surface. Formation of a bilayer is examined using fluorescence recovery after photobleaching. The results on the protein assembly on membranes present an important step in understanding the intermediate stages that occur during the dynamic movement of MinD in cells.

  13. Analyzing driving forces behind changes in energy vulnerability of Spanish electricity generation through a Divisia index-based method

    International Nuclear Information System (INIS)

    Highlights: • We propose and develop the LMDI approach to factorize changes in electricity bill vulnerability. • Spanish vulnerability (1995–2011) markedly grew mainly by increasing gas dependence. • Fuel price increase and growing importance of electricity damage energy security. • Energy intensity advances & fuel diversification: insufficient to drive vulnerability. • Main recommendation: enhance internal energy market and common external EU strategy. - Abstract: High energy dependence on fossil raises vulnerability concerns about security of supply and energy cost. This research examines the impact of high dependence of imported fuels for power generation in Spain through the quantification and analysis of the driving forces behind the change in its electricity bill. Following logarithmic mean Divisia indexes approach, we present and perform a new method that enables a complete decomposition of changes in electricity vulnerability into contributions from several drivers. In fact, we identify five predefined factors behind the variations in vulnerability in Spain during the 1998–2011 period: fuel price, average heat rate, fuel dependence, degree of electricity importance and energy intensity. The application of this approach reveals a significant increase in Spanish vulnerability in the last two decades, promoted by increments in fuel price and importance of electricity over the primary energy consumption, but especially by increasing fuel dependence (particularly gas dependence). Therefore, findings mainly advocate for those strategies aimed at reducing Spanish energy dependence. Also those improving thermal efficiency and energy intensity are indicated

  14. Entropic elasticity in the generation of muscle Force - A theoretical model

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2002-01-01

    -bridges are explored [linear, power function and worm-like chain (WLC) model based], and it is shown that the best results are obtained if the individual myosin-spring forces are modelled using a WLC model, thus hinting that entropic elasticity could be the main source of force in myosin undergoing the conformational...

  15. Examining the role of the tectorial membrane in otoacoustic emission generation

    Science.gov (United States)

    Cheatham, Marry Ann; Goodyear, Richard J.; Charaziak, Karolina K.; Conklin, Tess; Zheng, Jing; Dallos, Peter; Richardson, Guy P.; Siegel, Jonathan H.

    2015-12-01

    A mouse lacking CEACAM16, a member of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family of proteins, shows changes in tectorial membrane (TM) structure including loss of a defined striated-sheet matrix, absence of Hensen's stripe and increased porosity. In spite of these changes, thresholds for distortion product emissions (DPOAEs) and auditory brainstem responses (ABR) are near normal for most frequencies in the mouse audiogram [11]. In contrast, stimulus frequency emissions (SFOAE) are larger in knockouts (KO) and the incidence of spontaneous emissions (SOAE) is ˜70% [5]. This latter statistic is remarkable considering that SOAEs are uncommon in normal wild-type (WT) mice. In order to understand how the TM might influence emissions, SFOAE magnitude and phase were examined and group delays computed. As in humans, an approximately one-cycle phase change is observed in association with SFOAE fine structure. In addition, CEACAM16 KO mice and their WT controls showed similar group delays/phase slopes indicating no obvious changes in the mechanisms associated with emission generation.

  16. Independent Auditors Report on the Examination of Existence, Completeness, and Rights of United States Air Force Operating Materials and Supplies-Ammunition and Tactical Missiles

    Science.gov (United States)

    2015-08-21

    UNDER SECRETARY OF DEFENSE ( COMPTROLLER )/CHIEF FINANCIAL OFFICER, DOD ASSISTANT SECRETARY OF THE AIR FORCE (FINANCIAL MANAGEMENT AND COMPTROLLER ...2015-164 │ 3 August 21, 2015 MEMORANDUM FOR UNDER SECRETARY OF DEFENSE ( COMPTROLLER )/CHIEF FINANCIAL OFFICER, DOD ASSISTANT SECRETARY OF THE AIR...FORCE (FINANCIAL MANAGEMENT AND COMPTROLLER ) SUBJECT: Independent Auditor’s Report on the Examination of Existence, Completeness, and Rights of

  17. Supply Chain Management as a Driving Force for Generating Competitive Advantage for Dairy Companies

    Directory of Open Access Journals (Sweden)

    Irina Olegovna Poleshkina

    2016-11-01

    Full Text Available The study aims to uncover the reserves to generate competitive advantages for the participants of the market of perishables in the case of the dairy sector due to the formation of effective supply chains, as this category of goods is the most demanding in terms of periods and conditions of transportation and terms of preservation. The research technique is based on the concepts of value chains and supply chain management. In order to optimize the distribution of functions between the participants of the dairy chain a process-based approach has been applied. The research has revealed the main reasons for high aggregate costs and the places of their formation at each stage of the dairy supply chain. The article proposes the mechanisms to address three main problems arising from the process of building relations between the participants of the dairy supply chain in Russia. These problems are associated with a disproportionate margin distribution between the participants of the chain, with non-compliance of the quality of raw milk with the requirements for the production of specific types of dairy products, and with distrust of the supply chain participants, which increases transaction costs and forces to create reserve supplies which reduce the competitiveness of the whole dairy supply chain in general. In order to improve the competitiveness of all participants in the dairy chain, the article presents several mechanisms for solving these problems. The first is margin distribution based on the costs incurred by each participant of the dairy chain. The second is the use of a mathematical model to determine the assortment of goods of a dairy enterprise on the basis of the incoming volume and quality of raw milk according to the seasonal factor and the demand for dairy products. The third is the feasibility of refusal from the formation of reserve supplies by all participants of the dairy chain, which will not only minimize aggregate costs, but also

  18. Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-05

    A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprung dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.

  19. Mobile art pattern wind-force of generation of electricity of prod; Purodo no mobairu atogata furyoku hatsuden

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Yoriyasu

    1999-03-01

    How to think about usual force of the wind generation of electricity is the generation of electricity facilities where a propeller type is large-scale by the efficiency emphasis. However, as a scale grows bigger, it is understood more that it isn`t necessarily good if usual facilities are popularized when badness of the operating rate that it passes through the noise pollution and the year such as the velocity of the wind 4-5m/s of cut in and so on is taken into consideration. Even if the same force of the wind generation of electricity is said, it does from the beginning of the idea of cooperative plod, and a concept is wrong, and it is the story which must not be compared with a large force of the wind generator. The various functional beauty when that molding fruit stopped to become `the sculpture that wind can be seen` rather rotates is more important in the way of thinking about efficiency priority than to say an abstract expression such as `the love` which can`t have an idea, and `kindness` as sculpture to move by the wind when it says. (NEDO)

  20. Diagnostic examination of Generation 2 lithium-ion cells and assessment ofperformance degradation mechanisms.

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, D. P.; Dees, D. W.; Knuth, J.; Reynolds, E.; Gerald, R.; Hyung,Y.-E.; Belharouak, I.; Stoll, M.; Sammann, E.; MacLaren, S.; Haasch, R.; Twesten,R.; Sardela, M.; Battaglia, V.; Cairns, E.; Kerr, J.; Kerlau, M.; Kostecki, R.; Lei,J.; McCarthy, K.; McLarnon, F.; Reimer, J.; Richardson, T.; Ross, P.; Sloop,S.; Song, X.; Zhuang, V.; Balasubramanian, M.; McBreen, J.; Chung, K.-Y.; Yang, X.Q.; Yoon, W.-S.; Norin, L.

    2005-07-15

    The Advanced Technology Development (ATD) Program is a multilaboratory effort to assist industrial developers of high-power lithium-ion batteries overcome the barriers of cost, calendar life, abuse tolerance, and low-temperature performance so that this technology may be rendered practical for use in hybrid electric vehicles (HEVs). Included in the ATD Program is a comprehensive diagnostics effort conducted by researchers at Argonne National Laboratory (ANL), Brookhaven National Laboratory (BNL), and Lawrence Berkeley National Laboratory (LBNL). The goals of this effort are to identify and characterize processes that limit lithium-ion battery performance and calendar life, and ultimately to describe the specific mechanisms that cause performance degradation. This report is a compilation of the diagnostics effort conducted since spring 2001 to characterize Generation 2 ATD cells and cell components. The report is divided into a main body and appendices. Information on the diagnostic approach, details from individual diagnostic techniques, and details on the phenomenological model used to link the diagnostic data to the loss of 18650-cell electrochemical performance are included in the appendices. The main body of the report includes an overview of the 18650-cell test data, summarizes diagnostic data and modeling information contained in the appendices, and provides an assessment of the various mechanisms that have been postulated to explain performance degradation of the 18650 cells during accelerated aging. This report is intended to serve as a ready reference on ATD Generation 2 18650-cell performance and provide information on the tools for diagnostic examination and relevance of the acquired data. A comprehensive account of our experimental procedures and resulting data may be obtained by consulting the various references listed in the text. We hope that this report will serve as a roadmap for the diagnostic analyses of other lithium-ion technologies being

  1. Examining the Relations between Subjective Social Class, Academics, and Well-Being in First-Generation College Student Veterans

    Science.gov (United States)

    Colbow, Alexander James

    2017-01-01

    The aim of this study was to examine the relations between aspects of subjective social class, academic performance, and subjective wellbeing in first-generation and veteran students. In recent years, both student veterans and first-generation students have become topics of interest for universities, counselors, and researchers, as they are…

  2. EXAMINING HYPOTHESES GENERATED BY FIELD MEASURES OF SEXUAL SELECTION ON MALE LIZARDS, UTA PALMERI.

    Science.gov (United States)

    Hews, Diana K

    1990-12-01

    I examined sexual selection in the iguanid lizard Uta palmeri by measuring phenotypic selection in a cohort of males. Relative fitness was estimated by copulation rate from one breeding season, and I analyzed selection on five morphological traits (snout-vent length, mass, jaw length, head width, and head depth) and on male territory quality. Only territory quality and head depth were identified as direct targets of selection in a linear selection gradient analysis. Head depth was suggested to also be subject to quadratic selection. All traits exhibited significant directional selection differentials, suggesting indirect selection also was present because of the correlation of these traits with direct targets of selection. I used these results to generate hypotheses about the mechanisms of selection. For traits not identified as direct targets of selection (snout-vent length, mass, head width, jaw length), I could accept the null hypothesis of no female preference for the analyzed male traits; if these morphological traits were preferred by females in mate choice, they would have been identified as direct targets of selection. Exploring possible functional relationships within the cohort, I found that all five morphological traits contributed to explaining variation in territorial status. And in staged aggressive interactions between males that were similar in snout-vent length and mass, winning was associated only with greater head depth and not with head width or jaw length. Several possible interpretations of these results are presented. This study suggests that differential mating success arising from variation in territory quality gives rise to indirect selection on morphology. The possible mechanisms giving rise to the proposed direct selection on head depth require further study. © 1990 The Society for the Study of Evolution.

  3. Sympathetic activation by the cold pressor test does not increase the muscle force generation capacity.

    Science.gov (United States)

    Roatta, Silvestro; Farina, Dario

    2011-06-01

    A positive inotropic action by the sympathetic nervous system on skeletal muscles has been observed and investigated in animal and in vitro studies. This action provided a theoretical basis for the putative ergogenic action of catecholamines and adrenergic agonists, although there is no clear evidence of this effect in humans. The aim of this study was to investigate the occurrence of inotropic effects associated to physiological sympathetic activation in healthy subjects. The muscle force capacity was investigated in the tibialis anterior (n = 9 subjects) and in the soleus (n = 9) muscles electrically stimulated with single pulses and double pulses with variable interspike interval (4-1,000 ms) and short pulse trains (frequency: 5-14 Hz) before, during, and after sympathetic activation by the cold pressor test (CPT). CPT significantly decreased by 10.4 ± 7.2 and 10.6 ± 4.4% the force produced by single and double pulse stimulation, respectively, and produced smaller decreases in the force obtained by train stimulation in the tibialis anterior, while no significant changes were observed in either type of contraction in the soleus muscle. CPT failed to induce any increase in the force capacity of the investigated muscles. The prevalent decrease in force evidenced in this study supports the concept that the weakening sympathetic action on type I fiber, already shown to occur in humans, prevails over the putative potentiating action.

  4. Hilbert phase dynamometry (HPD) for real-time measurement of cell generated forces (Conference Presentation)

    Science.gov (United States)

    Sridharan, Shamira; Li, Yanfen; Bhaduri, Basanta; Majeed, Hassaan; Dupenloup, Paul; Levine, Alex; Kilian, Kristopher A.; Popescu, Gabriel

    2016-03-01

    Traction force microscopy is the most widely used technique for studying the forces exerted by cells on deformable substrates. However, the method is computationally intense and cells have to be detached from the substrate prior to measuring the displacement map. We have developed a new method, referred to as Hilbert phase dynamometry (HPD), which yields real-time force fields and, simultaneously, cell dry mass and growth information. HPD operates by imaging cells on a deformable substrate that is patterned with a grid of fluorescent proteins. A Hilbert transform is used to extract the phase map associated with the grid deformation, which provides the displacement field. By combining this information with substrate stiffness, an elasticity model was developed to measure forces exerted by cells with high spatial resolution. In our study, we prepared 10kPa gels and them with a 2-D grid of FITC-conjugated fibrinogen/fibronectin mixture, an extracellular matrix protein to which cells adhere. We cultured undifferentiated mesenchymal stem cells (MSC), and MSCs that were in the process of undergoing adipogenesis and osteogenesis. The cells were measured over the course of 24 hours using Spatial Light Interference Microscopy (SLIM) and wide-field epi-fluorescence microscopy allowing us to simultaneously measure cell growth and the forces exerted by the cells on the substrate.

  5. Generation of synthetic surface electromyography signals under fatigue conditions for varying force inputs using feedback control algorithm.

    Science.gov (United States)

    Venugopal, G; Deepak, P; Ghosh, Diptasree M; Ramakrishnan, S

    2017-11-01

    Surface electromyography is a non-invasive technique used for recording the electrical activity of neuromuscular systems. These signals are random, complex and multi-component. There are several techniques to extract information about the force exerted by muscles during any activity. This work attempts to generate surface electromyography signals for various magnitudes of force under isometric non-fatigue and fatigue conditions using a feedback model. The model is based on existing current distribution, volume conductor relations, the feedback control algorithm for rate coding and generation of firing pattern. The result shows that synthetic surface electromyography signals are highly complex in both non-fatigue and fatigue conditions. Furthermore, surface electromyography signals have higher amplitude and lower frequency under fatigue condition. This model can be used to study the influence of various signal parameters under fatigue and non-fatigue conditions.

  6. Meeting the challenges of the new energy industry: The driving forces facing electric power generators and the natural gas industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The proceedings of the IGT national conference on meeting the challenges of the New Energy Industry: The driving forces facing Electric Power Generators and the Natural Gas Industry are presented. The conference was held June 19-21, 1995 at the Ambassador West Hotel in Downtown Chicago, Illinois. A separate abstract and indexing for each of the 18 papers presented for inclusion in the Energy Science and Technology Database.

  7. Meeting the challenges of the new energy industry: The driving forces facing electric power generators and the natural gas industry

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The proceedings of the IGT national conference on meeting the challenges of the New Energy Industry: The driving forces facing Electric Power Generators and the Natural Gas Industry are presented. The conference was held June 19-21, 1995 at the Ambassador West Hotel in Downtown Chicago, Illinois. A separate abstract and indexing for each of the 18 papers presented for inclusion in the Energy Science and Technology Database

  8. Magnetic Circuit Model of PM Motor-Generator to Predict Radial Forces

    Science.gov (United States)

    McLallin, Kerry (Technical Monitor); Kascak, Peter E.; Dever, Timothy P.; Jansen, Ralph H.

    2004-01-01

    A magnetic circuit model is developed for a PM motor for flywheel applications. A sample motor is designed and modeled. Motor configuration and selection of materials is discussed, and the choice of winding configuration is described. A magnetic circuit model is described, which includes the stator back iron, rotor yoke, permanent magnets, air gaps and the stator teeth. Iterative solution of this model yields flux linkages, back EMF, torque, power, and radial force at the rotor caused by eccentricity. Calculated radial forces are then used to determine motor negative stiffness.

  9. Apoptosis generates mechanical forces that close the lens vesicle in the chick embryo

    Science.gov (United States)

    Oltean, Alina; Taber, Larry A.

    2018-03-01

    During the initial stages of eye development, optic vesicles grow laterally outward from both sides of the forebrain and come into contact with the surrounding surface ectoderm (SE). Within the region of contact, these layers then thicken locally to create placodes and invaginate to form the optic cup (primitive retina) and lens vesicle (LV), respectively. This paper examines the biophysical mechanisms involved in LV formation, which consists of three phases: (1) lens placode formation; (2) invagination to create the lens pit (LP); and (3) closure to form a complete ellipsoidally shaped LV. Previous studies have suggested that extracellular matrix deposited between the SE and optic vesicle causes the lens placode to form by locally constraining expansion of the SE as it grows, while actomyosin contraction causes this structure to invaginate. Here, using computational modeling and experiments on chick embryos, we confirm that these mechanisms for Phases 1 and 2 are physically plausible. Our results also suggest, however, that they are not sufficient to close the LP during Phase 3. We postulate that apoptosis provides an additional mechanism by removing cells near the LP opening, thereby decreasing its circumference and generating tension that closes the LP. This hypothesis is supported by staining that shows a ring of cell death located around the LP opening during closure. Inhibiting apoptosis in cultured embryos using caspase inhibitors significantly reduced LP closure, and results from a finite-element model indicate that closure driven by cell death is plausible. Taken together, our results suggest an important mechanical role for apoptosis in lens development.

  10. A new obstetrical polyurethane versus stainless steel forceps: a comparison of forces generated to the base of the fetal skull during simulated deliveries

    OpenAIRE

    Hale, Theodore M.; Shi, Zhengzhuan; Idangodage, Hasitha; Mercado, Ray; Skupski, Daniel; Veilastegui, Zoila

    2009-01-01

    Background: Decreasing the maximum force applied during traction to the base of the fetal skull using a less rigid polyurethane forceps is the basis of this study. Our hypothesis was that less force would be generated with polyurethane forceps than with steel forceps. Objective: To test a new soft polyurethane obstetrical forceps for maximal force generated to the base of the skull during simulated occiput anterior deliveries and to compare this to a similar shaped steel forceps. Methods: A...

  11. Special Forces Recruiting: The Operational Need for Targeted Recruitment of First and Second Generation Americans

    Science.gov (United States)

    2008-12-01

    Indigenous forces were recruited and trained by the OSS to operate from bases deep behind Japanese lines. Since American agents in Burma would attract...Team ( CLT ) is comprised of the Commander (SF) and First Sergeant (79R), and although these individuals are not included as recruiters, they do act

  12. Entropic elasticity in the generation of muscle Force - A theoretical model

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2002-01-01

    A novel simplified structural model of sarcomeric force production in striate muscle is presented. Using some simple assumptions regarding the distribution of myosin spring lengths at different sliding velocities it is possible to derive a very simple expression showing the main components...

  13. Use of a magnetic force exciter to vibrate a piezocomposite generating element in a small-scale windmill

    International Nuclear Information System (INIS)

    Luong, Hung Truyen; Goo, Nam Seo

    2012-01-01

    A piezocomposite generating element (PCGE) can be used to convert ambient vibrations into electrical energy that can be stored and used to power other devices. This paper introduces a design of a magnetic force exciter for a small-scale windmill that vibrates a PCGE to convert wind energy into electrical energy. A small-scale windmill was designed to be sensitive to low-speed wind in urban regions for the purpose of collecting wind energy. The magnetic force exciter consists of exciting magnets attached to the device’s input rotor and a secondary magnet fixed at the tip of the PCGE. The PCGE is fixed to a clamp that can be adjusted to slide on the windmill’s frame in order to change the gap between exciting and secondary magnets. Under an applied wind force, the input rotor rotates to create a magnetic force interaction that excites the PCGE. The deformation of the PCGE enables it to generate electric power. Experiments were performed with different numbers of exciting magnets and different gaps between the exciting and secondary magnets to determine the optimal configuration for generating the peak voltage and harvesting the maximum wind energy for the same range of wind speeds. In a battery-charging test, the charging time for a 40 mA h battery was approximately 3 h for natural wind in an urban region. The experimental results show that the prototype can harvest energy in urban regions with low wind speeds and convert the wasted wind energy into electricity for city use. (paper)

  14. ATK-ForceField: a new generation molecular dynamics software package

    Science.gov (United States)

    Schneider, Julian; Hamaekers, Jan; Chill, Samuel T.; Smidstrup, Søren; Bulin, Johannes; Thesen, Ralph; Blom, Anders; Stokbro, Kurt

    2017-12-01

    ATK-ForceField is a software package for atomistic simulations using classical interatomic potentials. It is implemented as a part of the Atomistix ToolKit (ATK), which is a Python programming environment that makes it easy to create and analyze both standard and highly customized simulations. This paper will focus on the atomic interaction potentials, molecular dynamics, and geometry optimization features of the software, however, many more advanced modeling features are available. The implementation details of these algorithms and their computational performance will be shown. We present three illustrative examples of the types of calculations that are possible with ATK-ForceField: modeling thermal transport properties in a silicon germanium crystal, vapor deposition of selenium molecules on a selenium surface, and a simulation of creep in a copper polycrystal.

  15. Optical forces generated by evanescent standing waves and their usage for sub-micron particle delivery

    Czech Academy of Sciences Publication Activity Database

    Šiler, Martin; Čižmár, Tomáš; Šerý, Mojmír; Zemánek, Pavel

    2006-01-01

    Roč. 84, 1-2 (2006), s. 157-165 ISSN 0946-2171 R&D Projects: GA AV ČR IAA1065203; GA MŠk(CZ) LC06007 EU Projects: European Commission(XE) 508952 - ATOM3D Institutional research plan: CEZ:AV0Z20650511 Keywords : total internal reflection * evanescent wave * optical force * colloidal particle * Rayleigh particle * interference optical trap Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.023, year: 2006

  16. Lonely Skies: Air-to-Air Training for a 5th Generation Fighter Force

    Science.gov (United States)

    2015-06-01

    2006, 1, http://www.af.mil/News/ArticleDisplay/tabid/223/ Article /128840/fighter-pilot- balanced-tactics-safety-effectiveness.aspx. 2 attempt to...Howard’s wisdom, the military scientist must aim at the imperfectly determined target of a future operational requirement and prepare the military forces...80), pilots faced growing complexity in their aircraft systems. The introduction of more advanced engine and hydraulic systems increased the

  17. Quantifying internally generated and externally forced climate signals at regional scales in CMIP5 models

    Science.gov (United States)

    Lyu, Kewei; Zhang, Xuebin; Church, John A.; Hu, Jianyu

    2015-11-01

    The Earth's climate evolves because of both internal variability and external forcings. Using Coupled Model Intercomparison Project Phase 5 (CMIP5) models, here we quantify the ratio of externally forced variance to total variance on interannual and longer time scales for regional surface air temperature (SAT) and sea level, which depends on the relative strength of externally forced signal compared to internal variability. The highest ratios are found in tropical areas for SAT but at high latitudes for sea level over the historical period when ocean dynamics and global mean thermosteric contributions are considered. Averaged globally, the ratios over a fixed time interval (e.g., 30 years) are projected to increase during the 21st century under the business-as-usual scenario (RCP8.5). In contrast, under two mitigation scenarios (RCP2.6 and RCP4.5), the ratio declines sharply by the end of the 21st century for SAT, but only declines slightly or stabilizes for sea level, indicating a slower response of sea level to climate mitigation.

  18. Wall Climbing Robot Using Electrostatic Adhesion Force Generated by Flexible Interdigital Electrodes

    Directory of Open Access Journals (Sweden)

    Rong Liu

    2013-01-01

    Full Text Available Electrostatic adhesion technology has broad application prospects on wall climbing robots because of its unique characteristics compared with other types of adhesion technologies. A double tracked wall climbing robot based on electrostatic adhesion technology is presented including electrode panel design, mechanical structure design, power supply system design and control system design. A theoretical adhesion model was established and the electrostatic potential and field were expressed by series expansions in terms of solutions of the Laplace function. Based on this model, the electrostatic adhesion force was calculated using the Maxwell stress tensor formulation. Several important factors which may influence the electrostatic adhesion force were analysed and discussed by both FEM simulation and theoretical calculation. In addition, experiments on the adhesion performance of the electrode panel and the climbing performance of the robot on various wall materials were carried out. Both the simulation and experiment results verify the feasibility of electrostatic adhesion technology being applied on wall climbing robots. The theoretical model and calculation method for the electrostatic adhesion force proposed in this paper are also justified.

  19. Vulnerability-specific stress generation: An examination of negative cognitive and interpersonal styles

    Science.gov (United States)

    Liu, Richard T.; Alloy, Lauren B.; Mastin, Becky M.; Choi, Jimmy Y.; Boland, Elaine M.; Jenkins, Abby L.

    2014-01-01

    Although there is substantial evidence documenting the stress generation effect in depression (i.e., the tendency for depression-prone individuals to experience higher rates of life stress to which they contribute), additional research is required to advance current understanding of the specific types of dependent stress (i.e., events influenced by characteristics and attendant behaviors of the individual) relevant to this effect. The present study tested an extension of the stress generation hypothesis, in which the content of dependent stress that is produced by depression-prone individuals is contingent upon, and matches, the nature of their particular vulnerabilities. This extension was tested within the context of two cognitive models (i.e., hopelessness theory [Abramson, Metalsky, & Alloy, 1989] and Cole’s [1990, 1991] competency-based model) and two interpersonal models (i.e., Swann’s [1987] self-verification theory and Coyne’s [1976] interpersonal theory) of depression. Overall, support was obtained for vulnerability-specific stress generation. Specifically, in analyses across vulnerability domains, evidence of stress-generation specificity was found for all domain-specific cognitive vulnerabilities except self-perceived social competence. The within-domain analyses for cognitive vulnerabilities produced more mixed results, but were largely supportive. Additionally, excessive reassurance-seeking was specifically predictive of dependent stress in the social domain, and moderated, but did not mediate, the relation between negative inferential styles overall and in the interpersonal domain and their corresponding generated stress. Finally, no evidence was found for a stress generation effect with negative feedback-seeking. PMID:24679143

  20. Entropy Generation Analysis and Performance Evaluation of Turbulent Forced Convective Heat Transfer to Nanofluids

    Directory of Open Access Journals (Sweden)

    Yu Ji

    2017-03-01

    Full Text Available The entropy generation analysis of fully turbulent convective heat transfer to nanofluids in a circular tube is investigated numerically using the Reynolds Averaged Navier–Stokes (RANS model. The nanofluids with particle concentration of 0%, 1%, 2%, 4% and 6% are treated as single phases of effective properties. The uniform heat flux is enforced at the tube wall. To confirm the validity of the numerical approach, the results have been compared with empirical correlations and analytical formula. The self-similarity profiles of local entropy generation are also studied, in which the peak values of entropy generation by direct dissipation, turbulent dissipation, mean temperature gradients and fluctuating temperature gradients for different Reynolds number as well as different particle concentration are observed. In addition, the effects of Reynolds number, volume fraction of nanoparticles and heat flux on total entropy generation and Bejan number are discussed. In the results, the intersection points of total entropy generation for water and four nanofluids are observed, when the entropy generation decrease before the intersection and increase after the intersection as the particle concentration increases. Finally, by definition of Ep, which combines the first law and second law of thermodynamics and attributed to evaluate the real performance of heat transfer processes, the optimal Reynolds number Reop corresponding to the best performance and the advisable Reynolds number Read providing the appropriate Reynolds number range for nanofluids in convective heat transfer can be determined.

  1. Sudden failure of implantable pulse generators: cause of failure and examination.

    Science.gov (United States)

    Lanmüller, Hermann; Buchroithner, Johanna; Wernisch, Johann; Alesch, François

    2007-10-01

    A sudden failure of implantable pulse generators used for spinal cord stimulation occurred in two patients. To identify the cause of this failure, an intensive destructive analysis of the explanted devices was carried out. A functional diagnosis was carried out by inspecting amplitude, pulse width and frequency on each output channel of the implantable pulse generators. Later, the titanium case of the pulse generators was opened by laser cutting to minimise any additional mechanical stress during the opening procedure. The functional test for both pulse generators showed faultless behaviour. Using light and electron microscopy, hairline cracks could be identified in the electrical connection between battery and electronic circuit. In both devices, the cracks spread through the whole bond wire in the connection to the plus pole of the battery and partially also to the minus pole. The analysis showed that both devices failed by broken bond wires. The electrical connection to the battery exists just by the spring characteristic of the wires. A push to the implant causes a short-term disconnection, resulting in a power on reset of the device. Manufacturing or design issues, allowing micromotion between battery and the hybrid part, may be the reason for this problem.

  2. Cases for the Net Generation: An Empirical Examination of Students' Attitude toward Multimedia Case Studies

    Science.gov (United States)

    Sheppard, Michael; Vibert, Conor

    2016-01-01

    Case studies have been an important tool in business, legal, and medical education for generations of students. Traditional text-based cases tend to be self-contained and structured in such a way as to teach a particular concept. The multimedia cases introduced in this study feature unscripted web-hosted video interviews with business owners and…

  3. Destructive Examinations on Divider Plates from Decommissioned Steam Generators Affected by Superficial Stress Corrosion Cracks

    Science.gov (United States)

    Miloudi, Salem; Firmin, Erwan; Deforge, Damien; Vaillant, François; Lemaire, Emmanuel

    Stress Corrosion Cracking of nickel alloys has been a major concern for all the Nuclear Power Plants over the last forty years. Since 2002, some cases of Stress Corrosion Cracking (SCC) have been reported on Steam Generator (SG) Divider Plates. However, evidence of propagation following the first detection has never been observed (based on nearly one hundred in-service inspections).

  4. Examining Psychokinesis: The Interaction of Human Intention with Random Number Generators--A Meta-Analysis

    Science.gov (United States)

    Bosch, Holger; Steinkamp, Fiona; Boller, Emil

    2006-01-01

    Seance-room and other large-scale psychokinetic phenomena have fascinated humankind for decades. Experimental research has reduced these phenomena to attempts to influence (a) the fall of dice and, later, (b) the output of random number generators (RNGs). The meta-analysis combined 380 studies that assessed whether RNG output correlated with human…

  5. Learning the Brain in Introductory Psychology: Examining the Generation Effect for Mnemonics and Examples

    Science.gov (United States)

    McCabe, Jennifer A.

    2015-01-01

    The goal of this research was to determine whether there is a generation effect for learner-created keyword mnemonics and real-life examples, compared to instructor-provided materials, when learning neurophysiological terms and definitions in introductory psychology. Students participated in an individual (Study 1) or small-group (Study 2)…

  6. Internally Generated and Externally Forced Multidecadal Oceanic Modes and their Influence on the Summer Rainfall over East Asia

    Science.gov (United States)

    Si, D.; Hu, A.

    2017-12-01

    The interdecadal oceanic variabilities can be generated from both internal and external processes, and these variabilities can significantly modulate our climate on global and regional scale, such as the warming slowdown in the early 21st century, and the rainfall in East Asia. By analyzing simulations from a unique Community Earth System Model (CESM) Large Ensemble (CESM_LE) project, we show that the Interdecadal Pacific Oscillation (IPO) is primarily an internally generated oceanic variability, while the Atlantic Multidecadal Oscillation (AMO) may be an oceanic variability generated by internal oceanic processes and modulated by external forcings in the 20th century. Although the observed relationship between IPO and the Yangtze-Huaihe River valley (YHRV) summer rainfall in China is well simulated in both the preindustrial control and 20th century ensemble, none of the 20th century ensemble members can reproduce the observed time evolution of both IPO and YHRV due to the unpredictable nature of IPO on multidecade timescale. On the other hand, although CESM_LE cannot reproduce the observed relationship between AMO and Huanghe River valley (HRV) summer rainfall of China in the preindustrial control simulation, this relationship in the 20th century simulations is well reproduced, and the chance to reproduce the observed time evolution of both AMO and HRV rainfall is about 30%, indicating the important role of the interaction between the internal processes and the external forcing to realistically simulate the AMO and HRV rainfall.

  7. Development of simulation technique and examination of mechanism for swelling of steam generator tube

    International Nuclear Information System (INIS)

    Kim, Seon Jin; Kim, Ki Nam; Park, Myung Chul; Shin, Gyeong Su; Cho, Jae Hwan

    2010-05-01

    This study was aimed at identifying the mechanism of the swelling through the development of simulation techniques for the swelling of steam generator tubes and correct understanding of swelling so as to evaluate the effect of swelling on soundness of steam generator based on results of the study. Test apparatus designed to simulate the tube swelling was fabricated and through a number of preliminary experiments at different conditions, swelling simulation was successfully completed. A tube swelling phenomenon is caused by a sort of ratcheting which is analyzable and is considered as a sort of fatigue phenomenon in which the stress is accumulated by action/reaction moment resulting from repeated impact of low energy, despite of hoop stress by internal pressure is significantly lower than yield strength of the material which has effect on hoop stress, overcoming the yield strength and causing the tubes to suffer plastic deformation

  8. Examination of the Properties of a Spent Fuel based Electricity Generation System - Scintillator Performance Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haneol; Yim, Man-Sung [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    Gammavoltaic was proposed by Karl Scharf in 1960. The low efficiency resulted in gammavoltaic being used as a radiation detector. In the 1990s the efficiency of gammavoltaic increased by the use of a scintillator. Gammavoltaic was further studied as a power source for spent fuel transportation and a nuclear battery in the 2000s Haneol Lee and Man-Sung Yim also suggested electricity generation system based on spent fuel stored inside the fuel pool of a nuclear power plant. This study proposed the systematic design of an electricity conversion system using CsI(Tl) scintillator and a-Si photovoltaic cell. As such, this study is selected to be a reference paper. The results of this paper indicate a self-absorption effect from the reference model. This effect is negligible while the irradiation degradation has to be considered. Two main ways to reduce radiation induced degradation are scintillator shielding and replacing scintillator material with a material having higher radiation resistance. The analysis of the scintillator used in the 'electricity generation system using gamma radiation from spent fuel' was performed to evaluate the ideal electricity generation in the reference research.

  9. Examination of the Properties of a Spent Fuel based Electricity Generation System - Scintillator Performance Analysis

    International Nuclear Information System (INIS)

    Lee, Haneol; Yim, Man-Sung

    2016-01-01

    Gammavoltaic was proposed by Karl Scharf in 1960. The low efficiency resulted in gammavoltaic being used as a radiation detector. In the 1990s the efficiency of gammavoltaic increased by the use of a scintillator. Gammavoltaic was further studied as a power source for spent fuel transportation and a nuclear battery in the 2000s Haneol Lee and Man-Sung Yim also suggested electricity generation system based on spent fuel stored inside the fuel pool of a nuclear power plant. This study proposed the systematic design of an electricity conversion system using CsI(Tl) scintillator and a-Si photovoltaic cell. As such, this study is selected to be a reference paper. The results of this paper indicate a self-absorption effect from the reference model. This effect is negligible while the irradiation degradation has to be considered. Two main ways to reduce radiation induced degradation are scintillator shielding and replacing scintillator material with a material having higher radiation resistance. The analysis of the scintillator used in the 'electricity generation system using gamma radiation from spent fuel' was performed to evaluate the ideal electricity generation in the reference research

  10. Effect of Hemipelvectomy Amputation on Kinematics and Muscle Force Generation of Lower Limb While Walking

    Directory of Open Access Journals (Sweden)

    Keyvan Sharifmoradi

    2017-07-01

    Conclusion The kinematics pattern of the patient’s lower limb during gait is different. Kinematic changes are associated with a significant increase in lower limb muscle generation that can have a degenerative effect on the knee joint. So the importance of this subject should be considered by rehabilitation experts.

  11. Effect of Magnetic Field on Entropy Generation Due to Laminar Forced Convection Past a Horizontal Flat Plate

    Directory of Open Access Journals (Sweden)

    Moh'd A. Al-Nimr

    2004-06-01

    Full Text Available Magnetic field effect on local entropy generation due to steady two-dimensional laminar forced convection flow past a horizontal plate was numerically investigated. This study was focused on the entropy generation characteristics and its dependency on various dimensionless parameters. The effect of various dimensionless parameters, such as Hartmann number (Ha, Eckert number (Ec, Prandtl number (Pr, Joule heating parameter (R and the free stream temperature parameter (θ∞ on the entropy generation characteristics is analyzed. The dimensionless governing equations in Cartesian coordinate were solved by an implicit finite difference technique. The solutions were carried out for Ha2=0.5-3, Ec=0.01-0.05, Pr=1-5 and θ∞=1.1-2.5. It was found that, the entropy generation increased with increasing Ha, Ec and R. While, increasing the free stream temperature parameter, and Prandtl number tend to decrease the local entropy generation.

  12. Mirror Worlds: Examining the Affordances of a Next Generation Immersive Learning Environment

    Science.gov (United States)

    Gautam, Aakash; Williams, Daron; Terry, Krista; Robinson, Kelly; Newbill, Phyllis

    2018-01-01

    As technologies continue to develop and evolve, it is imperative that instructional technologists, learning scientists, and educators involved with examining learning affordances of emerging technologies investigate the potential of innovative environments to promote and facilitate learning. This paper, as such, will describe a newly developed…

  13. Communities of Sound: Examining Meaningful Engagement with Generative Music Making and Virtual Ensembles

    Science.gov (United States)

    Dillon, Steve; Adkins, Barbara; Brown, Andrew; Hirche, Kathy

    2009-01-01

    In this article, we examine the affordances of the concept of "network jamming" as a means of facilitating social and cultural interaction, that provides a basis for unified communities that use sound and visual media as their key expressive medium. This article focuses upon the development of a means of measuring social and musical benefit…

  14. Examining runoff generation processes in the Selke catchment in central Germany: Insights from data and semi-distributed numerical model

    Directory of Open Access Journals (Sweden)

    Sumit Sinha

    2016-09-01

    New hydrological insights for the region: We examined the spatio-temporal variation of runoff generating mechanisms on the sub-basin level on seasonal basis. Our analysis reveals that the runoff generation in the Selke catchment is primarily dominated by shallow sub-surface flow and very rarely the contribution from Dunne overland flow exceeds sub-surface flow. Runoff generated by Hortonian mechanism is very infrequent and almost negligible. We also examined the spatio-temporal variation of runoff coefficients on seasonal basis as well as for individual storms. Due to higher precipitation and topographic relief in the upland catchment of Silberhutte, the runoff coefficients were consistently higher and its peak was found in winter months due to lower evapotranspiration.

  15. Quantification of intrusive/retraction force and moment generated during en-masse retraction of maxillary anterior teeth using mini-implants: A conceptual approach

    Directory of Open Access Journals (Sweden)

    A. Sumathi Felicita

    Full Text Available ABSTRACT Objective: The aim of the present study was to clarify the biomechanics of en-masse retraction of the upper anterior teeth and attempt to quantify the different forces and moments generated using mini-implants and to calculate the amount of applied force optimal for en-masse intrusion and retraction using mini-implants. Methods: The optimum force required for en-masse intrusion and retraction can be calculated by using simple mathematical formulae. Depending on the position of the mini-implant and the relationship of the attachment to the center of resistance of the anterior segment, different clinical outcomes are encountered. Using certain mathematical formulae, accurate measurements of the magnitude of force and moment generated on the teeth can be calculated for each clinical outcome. Results: Optimum force for en-masse intrusion and retraction of maxillary anterior teeth is 212 grams per side. Force applied at an angle of 5o to 16o from the occlusal plane produce intrusive and retraction force components that are within the physiologic limit. Conclusion: Different clinical outcomes are encountered depending on the position of the mini-implant and the length of the attachment. It is possible to calculate the forces and moments generated for any given magnitude of applied force. The orthodontist can apply the basic biomechanical principles mentioned in this study to calculate the forces and moments for different hypothetical clinical scenarios.

  16. Quantification of intrusive/retraction force and moment generated during en-masse retraction of maxillary anterior teeth using mini-implants: A conceptual approach.

    Science.gov (United States)

    Felicita, A Sumathi

    2017-01-01

    The aim of the present study was to clarify the biomechanics of en-masse retraction of the upper anterior teeth and attempt to quantify the different forces and moments generated using mini-implants and to calculate the amount of applied force optimal for en-masse intrusion and retraction using mini-implants. The optimum force required for en-masse intrusion and retraction can be calculated by using simple mathematical formulae. Depending on the position of the mini-implant and the relationship of the attachment to the center of resistance of the anterior segment, different clinical outcomes are encountered. Using certain mathematical formulae, accurate measurements of the magnitude of force and moment generated on the teeth can be calculated for each clinical outcome. Optimum force for en-masse intrusion and retraction of maxillary anterior teeth is 212 grams per side. Force applied at an angle of 5o to 16o from the occlusal plane produce intrusive and retraction force components that are within the physiologic limit. Different clinical outcomes are encountered depending on the position of the mini-implant and the length of the attachment. It is possible to calculate the forces and moments generated for any given magnitude of applied force. The orthodontist can apply the basic biomechanical principles mentioned in this study to calculate the forces and moments for different hypothetical clinical scenarios.

  17. Examination of a steam-generator tube section from the Zorita nuclear plant

    International Nuclear Information System (INIS)

    Stiegelmeyer, W.N.; Agrawal, A.K.

    1986-01-01

    One of the Zorita tubes (R18C43 HL) with the field EC indications on the ID was nondestructively and destructively examined. Also, deposits from the outside of the R18C53 HL were analyzed by several microchemical methods. The results of eddy current, radiography and dye penetrant examinations are given. Axial cracks, up to 80% thru wall, were found on the ID at the roll transition by dye penetrant exams. Similar OD tube sheet region intergranular attack (IGA), tube support plate region IGA and above tube sheet wastage were found as with tube R18C53 HL examined by Westinghouse. The microstructure of the tube R18C43 is shown. The results of a spark source mass spectroscopy (SSMS) analysis of deposits are given. This analysis indicates that the Na/P was >3 in the tube sheet crevice region sample and was <3 for the sample taken from the tube surface. An X-ray diffraction analysis performed on the core and surface samples showed that the deposits were primarily magnetite and copper with a mixture of phosphate compounds. The conclusions of this work are given. Free caustic was considered the likely cause of the OD surface IGA detected. High stresses in the roll transition were likely responsible for the ID axial cracks

  18. Electro-hydrodynamic force field and flow patterns generated by a DC corona discharge in the air

    Science.gov (United States)

    Monrolin, Nicolas; Plouraboue, Franck; Praud, Olivier

    2016-11-01

    Ionic wind refers to the electro-convection of ionised air between high voltage electrodes. Microscopic ion-neutral collisions are responsible for momentum transfer from accelerated ions, subjected to the electric field, to the neutral gas molecules resulting in a macroscopic airflow acceleration. In the past decades it has been investigated for various purposes from food drying through aerodynamic flow control and eventually laptop cooling. One consequence of air acceleration between the electrodes is thrust generation, often referred to as the Biefeld-Brown effect or electro-hydrodynamic thrust. In this experimental study, the ionic wind velocity field is measured with the PIV method. From computing the acceleration of the air we work out the electrostatic force field for various electrodes configurations. This enables an original direct evaluation of the force distribution as well as the influence of electrodes shape and position. Thrust computation based on the flow acceleration are compared with digital scale measurements. Complex flow features are highlighted such as vortex shedding, indicating that aerodynamic effects may play a significant role. Furthermore, the aerodynamic drag force exerted on the electrodes is quantified by choosing an appropriate control volume. Authors thank Region Midi-Pyrenee and CNES Launcher Directorate for financial support.

  19. Technical concept and evaluation of a novel shoulder simulator with adaptive muscle force generation and free motion

    Directory of Open Access Journals (Sweden)

    Verjans Mark

    2016-09-01

    Full Text Available The human shoulder is one of the most complex joints of the human body, and due to the high range of motion and the complex soft tissue apparatus prone to injuries. Surgical therapies and joint replacements often lead to unsatisfactory results. To improve the understanding of the complex biomechanics of the shoulder, experimental investigations have to be conducted. For this purpose a new shoulder simulator with an innovative muscle force generation was developed. On the basis of a modular concept six artificial pneumatic muscles were integrated to represent the functionally most important muscles of the shoulder joint, whereby a free and controlled movement of the humerus can be conducted. For each muscle individual setpoints for muscle length control based on a user defined shoulder movement for any artificial or cadaver specimen are created by manual motion “Teach-In”. Additional to muscle forces and lengths, optical tracking and a joint force measurement is used to enable different biomechanical studies of the shoulder joint. This paper describes the technical setup as well as the control strategy and first results of its experimental functional validation.

  20. Spin force and the generation of sustained spin current in time-dependent Rashba and Dresselhaus systems

    International Nuclear Information System (INIS)

    Ho, Cong Son; Tan, Seng Ghee; Jalil, Mansoor B. A.

    2014-01-01

    The generation of spin current and spin polarization in a two-dimensional electron gas structure is studied in the presence of Dresselhaus and Rashba spin-orbit couplings (SOC), the strength of the latter being modulated in time by an ac gate voltage. By means of the non-Abelian gauge field approach, we established the relation between the Lorentz spin force and the spin current in the SOC system, and showed that the longitudinal component of the spin force induces a transverse spin current. For a constant (time-invariant) Rashba system, we recover the universal spin Hall conductivity of e/(8π) , derived previously via the Berry phase and semi-classical methods. In the case of a time-dependent SOC system, the spin current is sustained even under strong impurity scattering. We evaluated the ac spin current generated by a time-modulated Rashba SOC in the absence of any dc electric field. The magnitude of the spin current reaches a maximum when the modulation frequency matches the Larmor frequency of the electrons

  1. Increased cross-bridge recruitment contributes to transient increase in force generation beyond maximal capacity in human myocardium.

    Science.gov (United States)

    Milani-Nejad, Nima; Chung, Jae-Hoon; Canan, Benjamin D; Fedorov, Vadim V; Whitson, Bryan A; Kilic, Ahmet; Mohler, Peter J; Janssen, Paul M L

    2018-01-01

    Cross-bridge attachment allows force generation to occur, and rate of tension redevelopment (k tr ) is a commonly used index of cross-bridge cycling rate. Tension overshoots have been observed briefly after a slack-restretch k tr maneuver in various species of animal models and humans. In this study, we set out to determine the properties of these overshoots and their possible underlying mechanism. Utilizing human cardiac trabeculae, we have found that tension overshoots are temperature-dependent and that they do not occur at resting states. In addition, we have found that myosin cross-bridge cycle is vital to these overshoots as inhibition of the cycle results in the blunting of the overshoots and the magnitude of the overshoots are dependent on the level of myofilament activation. Lastly, we show that the number of cross-bridges transiently increase during tension overshoots. These findings lead us to conclude that tension overshoots are likely due to a transient enhancement of the recruitment of myosin heads into the cross-bridge cycling, regulated by the myocardium, and with potential physiological significance in determining cardiac output. We show that isolated human myocardium is capable of transiently increasing its maximal force generation capability by increasing cross-bridge recruitment following slack-restretch maneuver. This process can potentially have important implications and significance in cardiac contraction in vivo. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Endothermic force generation, temperature-jump experiments and effects of increased [MgADP] in rabbit psoas muscle fibres.

    Science.gov (United States)

    Coupland, M E; Pinniger, G J; Ranatunga, K W

    2005-09-01

    We studied, by experiment and by kinetic modelling, the characteristics of the force increase on heating (endothermic force) in muscle. Experiments were done on maximally Ca2+-activated, permeabilized, single fibres (length approximately 2 mm; sarcomere length, 2.5 microm) from rabbit psoas muscle; [MgATP] was 4.6 mM, pH 7.1 and ionic strength was 200 mM. A small-amplitude (approximately 3 degrees C) rapid laser temperature-jump (0.2 ms T-jump) at 8-9 degrees C induced a tension rise to a new steady state and it consisted of two (fast and slow) exponential components. The T-jump-induced tension rise became slower as [MgADP] was increased, with half-maximal effect at 0.5 mM [MgADP]; the pre- and post-T-jump tension increased approximately 20% with 4 mM added [MgADP]. As determined by the tension change to small, rapid length steps (<1.4%L0 complete in <0.5 ms), the increase of force by [MgADP] was not associated with a concomitant increase of stiffness; the quick tension recovery after length steps (Huxley-Simmons phase 2) was slower with added MgADP. In steady-state experiments, the tension was larger at higher temperatures and the plot of tension versus reciprocal absolute temperature was sigmoidal, with a half-maximal tension at 10-12 degrees C; the relation with added 4 mM MgADP was shifted upwards on the tension axis and towards lower temperatures. The potentiation of tension with 4 mM added MgADP was 20-25% at low temperatures (approximately 5-10 degrees C), but approximately 10% at the physiological temperatures (approximately 30 degrees C). The shortening velocity was decreased with increased [MgADP] at low and high temperatures. The sigmoidal relation between tension and reciprocal temperature, and the basic effects of increased [MgADP] on endothermic force, can be qualitatively simulated using a five-step kinetic scheme for the crossbridge/A-MATPase cycle where the force generating conformational change occurs in a reversible step before the release of

  3. Examining of solid waste generation and community awareness between city center and suburban area in Medan City, Indonesia

    Science.gov (United States)

    Khair, H.; Putri, C. N.; Dalimunthe, R. A.; Matsumoto, T.

    2018-02-01

    Municipal solid waste (MSW) management is still an issue in many cities in Indonesia including Medan. Understanding the waste generation, its characteristic and communities involvement could provide effective solid waste management. This research compares waste generation from people who live in the city center and suburban area. The research also examines the willingness and participation of community about environmental aspect, especially solid waste management. The method of waste generation used Indonesian Nasional Standard 19-3964-1994. The city center generates 0.295 kg/person/day of solid waste and 0.180 kg/person/day for suburbs. The result showed that there are the common amount of waste compositions between the city center and suburban area. The majority waste composition was an organic fraction. Questionnaires were distributed to examine the community awareness. The descriptive statistic used to analyze the data. The result showed that people living in the city center are slightly higher in community awareness than in the suburb. This paper highlights that area of living could give some effect to solid waste generation, waste composition and rate of awareness.

  4. Guide to the safety design examination about light water reactor facilities for power generation

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This guide was compiled to evaluate the validity of the design policy when the safety design is examined at the time of the application for approval of the installation of nuclear reactors. About 7 years has elapsed since the existing guide was established, and the more appropriate guide to evaluate the safety should be made on the basis of the knowledge and experience accumulated thereafter. The range of application of this guide is limited to the above described evaluation, and it is not intended as the general standard for the design of nuclear reactors. First, the definition of the words used in this guide is given. Then, the guide to the safety examination is described about the general matters of reactor facilities, nuclear reactors and the measuring and controlling system, reactor-stopping system, reactivity-controlling system and safety protection system, reactor-cooling system, reactor containment vessels, fuel handling and waste treatment system. Several matters which require attention in the application of this guide or the clarification of the significance and interpretation of the guide itself were found, therefore the explanation about them was added at the end of this guide. (Kako, I.)

  5. Numerical study of entropy generation for forced convection flow and heat transfer of a Jeffrey fluid over a stretching sheet

    Directory of Open Access Journals (Sweden)

    Nemat Dalir

    2014-12-01

    Full Text Available Entropy generation for the steady two-dimensional laminar forced convection flow and heat transfer of an incompressible Jeffrey non-Newtonian fluid over a linearly stretching, impermeable and isothermal sheet is numerically investigated. The governing differential equations of continuity, momentum and energy are transformed using suitable similarity transformations to two nonlinear coupled ordinary differential equations (ODEs. Then the ODEs are solved by applying the numerical implicit Keller’s box method. The effects of various parameters of the flow and heat transfer including Deborah number, ratio of relaxation to retardation times, Prandtl number, Eckert number, Reynolds number and Brinkman number on dimensionless velocity, temperature and entropy generation number profiles are analyzed. The results reveal that the entropy generation number increases with the increase of Deborah number while the increase of ratio of relaxation to retardation times causes the entropy generation number to reduce. A comparative study of the numerical results with the results from an exact solution for the dimensionless velocity gradient at the sheet surface is also performed. The comparison shows excellent agreement within 0.05% error.

  6. The Beginning of Kinesin's Force-Generating Cycle Visualized at 9Angstrom Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, Charles V.; Downing, Kenneth H.

    2007-06-20

    We have used cryo-electron microscopy of kinesin-decorated microtubules to resolve the structure of the motor protein kinesin's crucial nucleotide response elements, switch I and the switch II helix, in kinesin's poorly understood nucleotide-free state. Both of the switch elements undergo conformational change relative to the microtubule-free state. The changes in switch I suggest a role for it in ''ejecting'' adenosine diphosphate when kinesin initially binds to the microtubule. The switch II helix has an N-terminal extension, apparently stabilized by conserved microtubule contacts, implying a microtubule activation mechanism that could convey the state of the bound nucleotide to kinesin's putative force-delivering element (the ''neck linker''). In deriving this structure, we have adapted an image-processing technique, single-particle reconstruction, for analyzing decorated microtubules. The resulting reconstruction visualizes the asymmetric seam present in native, 13-protofilament microtubules, and this method will provide an avenue to higher-resolution characterization of a variety of microtubule- binding proteins, as well as the microtubule itself.

  7. Myosin-independent cytokinesis inGiardiautilizes flagella to coordinate force generation and direct membrane trafficking.

    Science.gov (United States)

    Hardin, William R; Li, Renyu; Xu, Jason; Shelton, Andrew M; Alas, Germain C M; Minin, Vladimir N; Paredez, Alexander R

    2017-07-18

    Devoid of all known canonical actin-binding proteins, the prevalent parasite Giardia lamblia uses an alternative mechanism for cytokinesis. Unique aspects of this mechanism can potentially be leveraged for therapeutic development. Here, live-cell imaging methods were developed for Giardia to establish division kinetics and the core division machinery. Surprisingly, Giardia cytokinesis occurred with a median time that is ∼60 times faster than mammalian cells. In contrast to cells that use a contractile ring, actin was not concentrated in the furrow and was not directly required for furrow progression. Live-cell imaging and morpholino depletion of axonemal Paralyzed Flagella 16 indicated that flagella-based forces initiated daughter cell separation and provided a source for membrane tension. Inhibition of membrane partitioning blocked furrow progression, indicating a requirement for membrane trafficking to support furrow advancement. Rab11 was found to load onto the intracytoplasmic axonemes late in mitosis and to accumulate near the ends of nascent axonemes. These developing axonemes were positioned to coordinate trafficking into the furrow and mark the center of the cell in lieu of a midbody/phragmoplast. We show that flagella motility, Rab11, and actin coordination are necessary for proper abscission. Organisms representing three of the five eukaryotic supergroups lack myosin II of the actomyosin contractile ring. These results support an emerging view that flagella play a central role in cell division among protists that lack myosin II and additionally implicate the broad use of membrane tension as a mechanism to drive abscission.

  8. Isometric and eccentric force generation assessment of skeletal muscles isolated from murine models of muscular dystrophies.

    Science.gov (United States)

    Moorwood, Catherine; Liu, Min; Tian, Zuozhen; Barton, Elisabeth R

    2013-01-31

    Critical to the evaluation of potential therapeutics for muscular disease are sensitive and reproducible physiological assessments of muscle function. Because many pre-clinical trials rely on mouse models for these diseases, isolated muscle function has become one of the standards for Go/NoGo decisions in moving drug candidates forward into patients. We will demonstrate the preparation of the extensor digitorum longus (EDL) and diaphragm muscles for functional testing, which are the predominant muscles utilized for these studies. The EDL muscle geometry is ideal for isolated muscle preparations, with two easily accessible tendons, and a small size that can be supported by superfusion in a bath. The diaphragm exhibits profound progressive pathology in dystrophic animals, and can serve as a platform for evaluating many potential therapies countering fibrosis, and promoting myofiber stability. Protocols for routine testing, including isometric and eccentric contractions, will be shown. Isometric force provides assessment of strength, and eccentric contractions help to evaluate sarcolemma stability, which is disrupted in many types of muscular dystrophies. Comparisons of the expected results between muscles from wildtype and dystrophic muscles will also be provided. These measures can complement morphological and biochemical measurements of tissue homeostasis, as well as whole animal assessments of muscle function.

  9. EXPERIENCE SANITARY-EPIDEMIOLOGICAL EXAMINATION PROJECT OF PLACING A SOURCE OF IONIZING RADIATION (GENERATING) IN HEALTH CARE INSTITUTIONS

    OpenAIRE

    I. A. Rakitin; A. L. Zel’din; V. B. Karpov

    2015-01-01

    The article reviews the results of long-term sanitary-epidemiological examination of projects of placing of ionizing radiation (generating) sources in health care institutions of Saint-Petersburg. The majority among the placed sources presented for examination was X-ray diagnostic units and sets – 35.7%, dentist X-rays – 39.4% and fluorography units – 10.8%. Mammography units and computer tomographs made 6.7% each, accelerants – 0.7%.The most frequent reasons of primary refusals to accept des...

  10. Sexual orientation differences in teen pregnancy and hormonal contraceptive use: An examination across two generations

    Science.gov (United States)

    Charlton, Brittany M.; Corliss, Heather L.; Missmer, Stacey A.; Rosario, Margaret; Spiegelman, Donna; Austin, S. Bryn

    2013-01-01

    Objectives To examine whether sexual orientation is associated with disparities in teen pregnancy and hormonal contraception use among adolescent females in two intergenerational cohorts. Study Design Data were collected from 91,003 women in the Nurses’ Health Study II (NHSII),born between 1947–1964, and 6,463 of their children, born between 1982–1987, enrolled in the Growing Up Today Study (GUTS). Log-binomial models were used to estimate risk ratios (RR) for teen pregnancy and hormonal contraception use in sexual minorities compared to heterosexuals and meta-analysis techniques were used to compare the two cohorts. Results Overall, teen hormonal contraception use was lower and teen pregnancy was higher in NHSII than GUTS. In both cohorts, lesbians were less likely, whereas the other sexual minorities were more likely, to use hormonal contraception as teenagers compared to their heterosexual peers. All sexual minority groups in both cohorts, except NHSII lesbians, were at significantly increased risk for teen pregnancy, with RRs ranging from 1.61 (95%CI 0.40, 6.55) to 5.82 (95%CI 2.89, 11.73). Having a NHSII mother who was pregnant as a teen was not associated with teen pregnancy in GUTS participants. Finally, significant heterogeneity was found between the two cohorts. Conclusions Adolescent sexual minorities have been, and continue to be, at increased risk for pregnancy. Public health and clinical efforts are needed to address teen pregnancy in this population. PMID:23796650

  11. Sexual orientation differences in teen pregnancy and hormonal contraceptive use: an examination across 2 generations.

    Science.gov (United States)

    Charlton, Brittany M; Corliss, Heather L; Missmer, Stacey A; Rosario, Margaret; Spiegelman, Donna; Austin, S Bryn

    2013-09-01

    To examine whether sexual orientation is associated with disparities in teen pregnancy and hormonal contraception use among adolescent females in 2 intergenerational cohorts. Data were collected from 91,003 women in the Nurses' Health Study II (NHSII), born between 1947-1964, and 6463 of their children, born between 1982-1987, enrolled in the Growing Up Today Study (GUTS). Log-binomial models were used to estimate risk ratios for teen pregnancy and hormonal contraception use in sexual minorities compared with heterosexuals and metaanalysis techniques were used to compare the 2 cohorts. Overall, teen hormonal contraception use was lower and teen pregnancy was higher in NHSII than GUTS. In both cohorts, lesbians were less likely, whereas the other sexual minorities were more likely, to use hormonal contraception as teenagers compared with their heterosexual peers. All sexual minority groups in both cohorts, except NHSII lesbians, were at significantly increased risk for teen pregnancy, with risk ratios ranging from 1.61 (95% confidence interval, 0.40-6.55) to 5.82 (95% confidence interval, 2.89-11.73). Having an NHSII mother who was pregnant as a teen was not associated with teen pregnancy in GUTS participants. Finally, significant heterogeneity was found between the 2 cohorts. Adolescent sexual minorities have been, and continue to be, at increased risk for pregnancy. Public health and clinical efforts are needed to address teen pregnancy in this population. Copyright © 2013 Mosby, Inc. All rights reserved.

  12. Detection of Infectious Influenza Virus in Cough Aerosols Generated in a Simulated Patient Examination Room

    Science.gov (United States)

    Noti, John D.; Lindsley, William G.; Blachere, Francoise M.; Cao, Gang; Kashon, Michael L.; Thewlis, Robert E.; McMillen, Cynthia M.; King, William P.; Szalajda, Jonathan V.; Beezhold, Donald H.

    2015-01-01

    Background The potential for aerosol transmission of infectious influenza virus (ie, in healthcare facilities) is controversial. We constructed a simulated patient examination room that contained coughing and breathing manikins to determine whether coughed influenza was infectious and assessed the effectiveness of an N95 respirator and surgical mask in blocking transmission. Methods National Institute for Occupational Safety and Health aerosol samplers collected size-fractionated aerosols for 60 minutes at the mouth of the breathing manikin, beside the mouth, and at 3 other locations in the room. Total recovered virus was quantitated by quantitative polymerase chain reaction and infectivity was determined by the viral plaque assay and an enhanced infectivity assay. Results Infectious influenza was recovered in all aerosol fractions (5.0% in >4 µm aerodynamic diameter, 75.5% in 1–4 µm, and 19.5% in <1 µm; n = 5). Tightly sealing a mask to the face blocked entry of 94.5% of total virus and 94.8% of infectious virus (n = 3). A tightly sealed respirator blocked 99.8% of total virus and 99.6% of infectious virus (n = 3). A poorly fitted respirator blocked 64.5% of total virus and 66.5% of infectious virus (n = 3). A mask documented to be loosely fitting by a PortaCount fit tester, to simulate how masks are worn by healthcare workers, blocked entry of 68.5% of total virus and 56.6% of infectious virus (n = 2). Conclusions These results support a role for aerosol transmission and represent the first reported laboratory study of the efficacy of masks and respirators in blocking inhalation of influenza in aerosols. The results indicate that a poorly fitted respirator performs no better than a loosely fitting mask. PMID:22460981

  13. Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape

    Science.gov (United States)

    Taylor, Andrea B.; Vinyard, Christopher J.

    2009-01-01

    Cebus apella is renowned for its dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between the tufted capuchin (C. apella; n = 12 ) and two “untufted” capuchins (C. capuchinus, n = 3; C. albifrons, n = 5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that C. apella exhibits architectural properties of their jaw muscles that facilitate relatively large forces, including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P0). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter, whole masseter, and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P0. As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in C. apella primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear

  14. Using optical tweezers to examine the chemotactic force to a single inflammatory cell--eosinophil stimulated by chemoattractants prepared from Toxocara Canis larvae

    Science.gov (United States)

    Shih, Po-Chen; Su, Yi-Jr; Chen, Ke-Min; Jen, Lin-Ni; Liu, Cheng-tzu; Hsu, Long

    2005-08-01

    Granulocytes are a group of white blood cells belonging to the innate immune system in human and in murine in which eosinophils play an important role in worm infection-induced inflammation. The migration of these cells is well characterized and has been separated into four steps: rolling, adhesion, transendothelial migration, and chemotaxis, however, the physical characteristics of the chemotactic force to eosinophils from worm component remain largely unknown. Note that optical tweezers are featured in the manipulation of a single cell and the measurement of biological forces. Therefore, we propose to use optical tweezers to examine the chemotactic force to a eosinophil from a T. canis lavae preparation in terms of distance during the migration of eosinophil.

  15. Characterization of polymer surface structure and surface mechanical behaviour by sum frequency generation surface vibrational spectroscopy and atomic force microscopy

    International Nuclear Information System (INIS)

    Opdahl, Aric; Koffas, Telly S; Amitay-Sadovsky, Ella; Kim, Joonyeong; Somorjai, Gabor A

    2004-01-01

    Sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM) have been used to study polymer surface structure and surface mechanical behaviour, specifically to study the relationships between the surface properties of polymers and their bulk compositions and the environment to which the polymer is exposed. The combination of SFG surface vibrational spectroscopy and AFM has been used to study surface segregation behaviour of polyolefin blends at the polymer/air and polymer/solid interfaces. SFG surface vibrational spectroscopy and AFM experiments have also been performed to characterize the properties of polymer/liquid and polymer/polymer interfaces, focusing on hydrogel materials. A method was developed to study the surface properties of hydrogel contact lens materials at various hydration conditions. Finally, the effect of mechanical stretching on the surface composition and surface mechanical behaviour of phase-separated polyurethanes, used in biomedical implant devices, has been studied by both SFG surface vibrational spectroscopy and AFM. (topical review)

  16. Environmental Attitudes and Behaviors: An Examination of the Antecedents of Behavior Among Air Force Members at Work

    National Research Council Canada - National Science Library

    Laudenslager, Mark

    1996-01-01

    .... The behaviors and intentions individuals have towards recycling, energy conservation, and carpooling were examined, with the demographic variables of gender, age, and education also investigated...

  17. Effect of combined actions of hip adduction/abduction on the force generation and maintenance of pelvic floor muscles in healthy women.

    Directory of Open Access Journals (Sweden)

    Amanda C Amorim

    Full Text Available Pelvic floor muscle (PFM force and coordination are related to urinary incontinence severity and to sexual satisfaction. Health professionals frequently combine classic PFM exercises with hip adduction/abduction contraction to treat these disorders, but the real benefits of this practice are still unknown. Based on a theoretical anatomy approach whereby the levator ani muscle is inserted into the obturator internus myofascia and in which force generated by hip movements should increase the contraction quality of PFMs, our aim was to investigate the effects of isometric hip adduction and abduction on PFM force generation. Twenty healthy, nulliparous women were evaluated using two strain-gauge dynamometers (one cylinder-like inside the vaginal cavity, and the other measuring hip adduction/abduction forces around both thighs while performing three different tasks: (a isolated PFM contraction; (b PFM contraction combined with hip adduction (30% and 50% maximum hip force; and (c PFM contraction combined with hip abduction (30% and 50% maximum hip force. Data were sampled at 100Hz and subtracted from the offset if existent. We calculated a gradient between the isolated PFM contraction and each hip condition (Δ Adduction and Δ Abduction for all variables: Maximum force (N, instant of maximum-force occurrence (s, mean force in an 8-second window (N, and PFM force loss (N.s. We compared both conditions gradients in 30% and 50% by paired t-tests. All variables did not differ between hip conditions both in 30% and 50% of maximum hip force (p>.05. PFM contraction combined with isometric hip abduction did not increase vaginal force in healthy and nulliparous women compared to PFM contraction combined with isometric hip adduction. Therefore, so far, the use of hip adduction or abduction in PFM training and treatments are not justified for improving PFM strength and endurance.

  18. A new obstetrical polyurethane versus stainless steel forceps: a comparison of forces generated to the base of the fetal skull during simulated deliveries.

    Science.gov (United States)

    Hale, Theodore M; Shi, Zhengzhuan; Idangodage, Hasitha; Mercado, Ray; Skupski, Daniel; Veilastegui, Zoila

    2009-01-01

    Decreasing the maximum force applied during traction to the base of the fetal skull using a less rigid polyurethane forceps is the basis of this study. Our hypothesis was that less force would be generated with polyurethane forceps than with steel forceps. To test a new soft polyurethane obstetrical forceps for maximal force generated to the base of the skull during simulated occiput anterior deliveries and to compare this to a similar shaped steel forceps. After designing a prototype polyurethane forceps, we used a pelvic manikin model and a fetal manikin model. Force and load sensors were attached at the inner tips of the distal forceps blade. A Tekscan 201 (accurate for measuring 0-25 pounds of force) 0.0008 inches flexible printed circuit was used that measured contact forces. Forceps with an attached calibrated sensor were applied to the fetal head while inside the pelvic model. The median maximum traction force at the base of the fetal skull was 4.60 pounds (range 4.3-4.62) for polyurethane forceps vs. 9.52 pounds (range 9.22-9.52) for steel forceps (P=0.027). The polyurethane forceps applied 50% less overall mechanical force than the steel forceps at the tip of the forceps and base of the skull during simulated occiput anterior outlet deliveries.

  19. Celery (Apium graveolens L.) parenchyma cell walls examined by atomic force microscopy: effect of dehydration on cellulose microfibrils.

    Science.gov (United States)

    Thimm, J C; Burritt, D J; Ducker, W A; Melton, L D

    2000-12-01

    Atomic force microscopy (AFM) was used to image celery (Apium graveolens L.) parenchyma cell walls in situ. Cellulose microfibrils could clearly be distinguished in topographic images of the cell wall. The microfibrils of the hydrated walls appeared smaller, more uniformly distributed, and less enmeshed than those of dried peels. In material that was kept hydrated at all times and imaged under water, the microfibril diameter was mainly in the range 6-25 nm. The cellulose microfibril diameters were highly dependent on the water content of the specimen. As the water content was decreased, by mixing ethanol with the bathing solution, the microfibril diameters increased. Upon complete dehydration of the specimen we observed a significant increase in microfibril diameter. The procedure used to dehydrate the parenchyma cells also influenced the size of cellulose microfibrils with freeze-dried material having larger diameters than air-dried material.

  20. The apparent rate constant for the dissociation of force generating myosin crossbridges from actin decreases during Ca2+ activation of skinned muscle fibres.

    Science.gov (United States)

    Kerrick, W G; Potter, J D; Hoar, P E

    1991-02-01

    The effect of Ca2+ activation on the apparent rate constant governing the dissociation of force generating myosin crossbridges was studied in skinned rabbit adductor magnus fibres (fast-twitch) at 21 +/- 1 degree C. Simultaneous measurements of Ca2(+)-activated isometric force and ATPase activity were conducted in parallel with simultaneous measurements of DANZ-labelled troponin C (TnCDANZ) fluorescence and isometric force in fibres whose endogenous troponin C had been partially replaced with TnCDANZ. The Ca2+ activation of isometric force occurred at approximately two times higher Ca2+ concentration than did actomyosin ATPase activity at 2.0 mM MgATP. Since increases in both TnCDANZ fluorescence and ATPase activity occurred over approximately the same Ca2+ concentration range at substantially lower concentrations of Ca2+ than did force, this data suggests that the TnCDANZ fluorescence is associated with the Ca2+ activation of myosin crossbridge turnover (ATPase) rather than force. According to the model of Huxley (1957) and assuming the hydrolysis of one molecule of ATP per cycle of the crossbridge, the apparent rate constant gapp for the dissociation of force generating myosin crossbridges is proportional to the actomyosin ATPase/isometric force ratio. This measure of gapp shows approximately a fivefold decrease during Ca2+ activation of isometric force. This change in gapp is responsible for separation of the Ca2+ sensitivity of the normalized ATPase activity and isometric force curves. If the MgATP concentration is reduced to 0.5 mM, the change in gapp is reduced and consequently the difference in Ca2+ sensitivity between normalized steady state ATPase and force is also reduced.

  1. Tide generating forces

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    stream_size 3 stream_content_type text/plain stream_name Trg_Calculat_Water_Depth_Chart_Datum_1991_3.pdf.txt stream_source_info Trg_Calculat_Water_Depth_Chart_Datum_1991_3.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  2. Grandparenting and mothers' labour force participation: A comparative analysis using the Generations and Gender Survey

    Directory of Open Access Journals (Sweden)

    Arnstein Aassve

    2012-07-01

    Full Text Available BACKGROUND It is well known that the provision of public childcare plays an important role for women labour force participation and its availability varies tremendously across countries. In many countries, informal childcare is also important and typically provided by the grandparents, but its role on mothers' employment is not yet well understood. Understanding the relationship between labour supply decisions and grandparental childcare is complex. While the provision of grandparental childcare is clearly a function of the social and institutional context of a country, it also depends on family preferences, which are typically unobserved in surveys. OBJECTIVE We analyze the role of informal childcare provided by grandparents on mothers' labour force participation keeping unobserved preferences into account. METHODS Bivariate probit models with instrumental variables are estimated on data from seven countries (Bulgaria, France, Georgia, Germany, Hungary, Russia and The Netherlands drawn from the Generations and Gender Survey. RESULTS We find that only in some countries mothers' employment is positively and significantly associated with grandparents providing childcare. In other countries, once we control for unobserved preferences, we do not find this effect. CONCLUSIONS The role of grandparents is an important element to reconcile work and family for women in some countries. Our results show the importance of considering family preferences and country differences when studying the relationship between grandparental childcare and mothers' labour supply. COMMENTS Our results are consistent with previous research on this topic. However, differently from previous studies, we conduct separate analyses by country and show that the effect of grandparental childcare varies considerably. The fact that we also include in the analyses Bulgaria, Hungary, Russia and Georgia is an important novelty as there are no studies on this issue

  3. Complex myograph allows the examination of complex muscle contractions for the assessment of muscle force, shortening, velocity, and work in vivo

    Directory of Open Access Journals (Sweden)

    Ruhschulte Hainer

    2008-07-01

    Full Text Available Abstract Background The devices used for in vivo examination of muscle contractions assess only pure force contractions and the so-called isokinetic contractions. In isokinetic experiments, the extremity and its muscle are artificially moved with constant velocity by the measuring device, while a tetanic contraction is induced in the muscle, either by electrical stimulation or by maximal voluntary activation. With these systems, experiments cannot be performed at pre-defined, constant muscle length, single contractions cannot be evaluated individually and the separate examination of the isometric and the isotonic components of single contractions is not possible. Methods The myograph presented in our study has two newly developed technical units, i.e. a. a counterforce unit which can load the muscle with an adjustable, but constant force and b. a length-adjusting unit which allows for both the stretching and the contraction length to be infinitely adjustable independently of one another. The two units support the examination of complex types of contraction and store the counterforce and length-adjusting settings, so that these conditions may be accurately reapplied in later sessions. Results The measurement examples presented show that the muscle can be brought to every possible pre-stretching length and that single isotonic or complex isometric-isotonic contractions may be performed at every length. The applied forces act during different phases of contraction, resulting into different pre- and after-loads that can be kept constant – uninfluenced by the contraction. Maximal values for force, shortening, velocity and work may be obtained for individual muscles. This offers the possibility to obtain information on the muscle status and to monitor its changes under non-invasive measurement conditions. Conclusion With the Complex Myograph, the whole spectrum of a muscle's mechanical characteristics may be assessed.

  4. NRC Fact-Finding Task Force report on the ATWS event at Salem Nuclear Generating Station, Unit 1, on February 25, 1983

    International Nuclear Information System (INIS)

    1983-03-01

    An NRC Region I Task Force was established on March 1, 1983 to conduct fact finding and data collection with regard to the circumstances which led to an anticipated transient without scram (ATWS) event at the Public Service Electric and Gas Company's Salem Generating Station, Unit 1 on February 25, 1983. The charter of the Task Force was to determine the factual information pertinent to management and administrative controls which should have ensured proper operation of the reactor trip breakers in the solid state protection system. This report documents the findings of the Task Force along with its conclusions

  5. An intervention study examining the effects of condom wrapper graphics and scent on condom use in the Botswana Defence Force.

    Science.gov (United States)

    Tran, Bonnie Robin; Thomas, Anne Goldzier; Vaida, Florin; Ditsela, Mooketsi; Phetogo, Robert; Kelapile, David; Haubrich, Richard; Chambers, Christina; Shaffer, Richard

    2014-01-01

    Free condoms provided by the government are often not used by Botswana Defence Force (BDF) personnel due to a perceived unpleasant scent and unattractive wrapper. Formative work with the BDF found that scented condoms and military-inspired (camouflage) wrapper graphics were appealing to personnel. A non-randomized intervention study was implemented to determine whether condom wrapper graphics and scent improved condom use in the BDF. Four military sites were selected for participation. Two sites in the south received the intervention condom wrapped in a generic wrapper and two sites in the north received the intervention condom wrapped in a military-inspired wrapper; intervention condoms were either scented or unscented. Two hundred and eleven male soldiers who ever had sex, aged 18-30 years, and stationed at one of the selected sites consented to participate. Sexual activity and condom use were measured pre- and post-intervention using sexual behavior diaries. A condom use rate (CUR; frequency of protected sex divided by the total frequency of sex) was computed for each participant. Mean CURs significantly increased over time (85.7% baseline vs. 94.5% post-intervention). Adjusted odds of condom use over time were higher among participants who received the intervention condom packaged in the military wrapper compared with the generic wrapper. Adjusted odds of condom use were also higher for participants who reported using scented vs. unscented condoms. Providing scented condoms and condoms packaged in a military-inspired wrapper may help increase condom use and reduce HIV infection among military personnel.

  6. Timing differences in the generation of ground reaction forces between the initial and secondary landing phases of the drop vertical jump ☆

    Science.gov (United States)

    Bates, Nathaniel A.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

    2014-01-01

    Background Rapid impulse loads imparted on the lower extremity from ground contact when landing from a jump may contribute to ACL injury prevalence in female athletes. The drop jump and drop landing tasks enacted in the first and second landings of drop vertical jumps, respectively, have been shown to elicit separate neuromechanical responses. We examined the first and second landings of a drop vertical jump for differences in landing phase duration, time to peak force, and rate of force development. Methods 239 adolescent female basketball players completed drop vertical jumps from an initial height of 31 cm. In-ground force platforms and a three dimensional motion capture system recorded force and positional data for each trial. Findings Between the first and second landing, rate of force development experienced no change (P > 0.62), landing phase duration decreased (P = 0.01), and time to peak ground reaction force increased (P 0.12). Interpretation The current results have important implications for the future assessment of ACL injury risk behaviors. Rate of force development remained unchanged between first and second landings from equivalent fall height, while time to peak reaction force increased during the second landing. Neither factor was dependent on the total time duration of landing phase, which decreased during the second landing. Shorter time to peak force may increase ligament strain and better represent the abrupt joint loading that is associated with ACL injury risk. PMID:23899938

  7. Timing differences in the generation of ground reaction forces between the initial and secondary landing phases of the drop vertical jump.

    Science.gov (United States)

    Bates, Nathaniel A; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

    2013-08-01

    Rapid impulse loads imparted on the lower extremity from ground contact when landing from a jump may contribute to ACL injury prevalence in female athletes. The drop jump and drop landing tasks enacted in the first and second landings of drop vertical jumps, respectively, have been shown to elicit separate neuromechanical responses. We examined the first and second landings of a drop vertical jump for differences in landing phase duration, time to peak force, and rate of force development. 239 adolescent female basketball players completed drop vertical jumps from an initial height of 31cm. In-ground force platforms and a three dimensional motion capture system recorded force and positional data for each trial. Between the first and second landing, rate of force development experienced no change (P>0.62), landing phase duration decreased (P=0.01), and time to peak ground reaction force increased (P0.12). The current results have important implications for the future assessment of ACL injury risk behaviors. Rate of force development remained unchanged between first and second landings from equivalent fall height, while time to peak reaction force increased during the second landing. Neither factor was dependent on the total time duration of landing phase, which decreased during the second landing. Shorter time to peak force may increase ligament strain and better represent the abrupt joint loading that is associated with ACL injury risk. © 2013.

  8. Data analysis algorithms for flaw sizing based on eddy current rotating probe examination of steam generator tubes

    International Nuclear Information System (INIS)

    Bakhtiari, S.; Elmer, T.W.

    2009-01-01

    Computer-aided data analysis tools can help improve the efficiency and reliability of flaw sizing based on nondestructive examination data. They can further help produce more consistent results, which is important for both in-service inspection applications and for engineering assessments associated with steam generator tube integrity. Results of recent investigations at Argonne on the development of various algorithms for sizing of flaws in steam generator tubes based on eddy current rotating probe data are presented. The research was carried out as part of the activities under the International Steam Generator Tube Integrity Program (ISG-TIP) sponsored by the U.S. Nuclear Regulatory Commission. A computer-aided data analysis tool has been developed for off-line processing of eddy current inspection data. The main objectives of the work have been to a) allow all data processing stages to be performed under the same user interface, b) simplify modification and testing of signal processing and data analysis scripts, and c) allow independent evaluation of viable flaw sizing algorithms. The focus of most recent studies at Argonne has been on the processing of data acquired with the +Point probe, which is one of the more widely used eddy current rotating probes for steam generator tube examinations in the U.S. The probe employs a directional surface riding differential coil, which helps reduce the influence of tubing artifacts and in turn helps improve the signal-to-noise ratio. Various algorithms developed under the MATLAB environment for the conversion, segmentation, calibration, and analysis of data have been consolidated within a single user interface. Data acquired with a number of standard eddy current test equipment are automatically recognized and converted to a standard format for further processing. Because of its modular structure, the graphical user interface allows user-developed routines to be easily incorporated, modified, and tested independent of the

  9. Recommendations concerning Tennessee's hazardous waste management policies by a task force representing generators, environmentalists, and other key constituencies

    International Nuclear Information System (INIS)

    Colglazier, E.W.; English, M.R.

    1987-01-01

    Four recommendations are proposed. 1) A Governor's Roundtable on Hazardous and Solid Wastes should be established to ensure that Tennessee have sound policies and plans for waste management, adequate waste treatment and disposal capacity, and the means to meet the October, 1989 deadline for certification of hazardous waste capacity. 2) Opportunities for early public information and participation in Tennessee's RCRA permitting process should be improved. 3) A Superfund Public Involvement Task Force should be appointed by the Commissioner of Health and Environment to find ways to ensure that a community affected by a Tennessee Superfund site has early and adequate opportunities for information and involvement. 4) Communications about hazardous waste issues should be improved by the appointment of a hazardous waste information officer, the establishment of a Speakers Bureau, the funding of the UT Center for Industrial Services' Hazardous Waste Extension Program, establishment of a crisis situation network of consultants for communities, and exploration of the possibility of Amnesty Days for household hazardous waste and for small-quantity generators waste

  10. Air-coupled acoustic radiation force for non-contact generation of broadband mechanical waves in soft media

    Energy Technology Data Exchange (ETDEWEB)

    Ambroziński, Łukasz [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); AGH University of Science and Technology, Krakow 30059 (Poland); Pelivanov, Ivan, E-mail: ivanp3@uw.edu [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Faculty of Physics, Moscow State University, Moscow 119991 (Russian Federation); Song, Shaozhen; Yoon, Soon Joon; Gao, Liang; O' Donnell, Matthew [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Li, David [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Chemical Engineering, University of Washington Seattle, Washington 98195 (United States); Shen, Tueng T.; Wang, Ruikang K. [Department of Bioengineering, University of Washington, Seattle, Washington 98195 (United States); Department of Ophthalmology, University of Washington, Seattle, Washington 98104 (United States)

    2016-07-25

    A non-contact method for efficient, non-invasive excitation of mechanical waves in soft media is proposed, in which we focus an ultrasound (US) signal through air onto the surface of a medium under study. The US wave reflected from the air/medium interface provides radiation force to the medium surface that launches a transient mechanical wave in the transverse (lateral) direction. The type of mechanical wave is determined by boundary conditions. To prove this concept, a home-made 1 MHz piezo-ceramic transducer with a matching layer to air sends a chirped US signal centered at 1 MHz to a 1.6 mm thick gelatin phantom mimicking soft biological tissue. A phase-sensitive (PhS)-optical coherence tomography system is used to track/image the mechanical wave. The reconstructed transient displacement of the mechanical wave in space and time demonstrates highly efficient generation, thus offering great promise for non-contact, non-invasive characterization of soft media, in general, and for elasticity measurements in delicate soft tissues and organs in bio-medicine, in particular.

  11. A modified blade element theory for estimation of forces generated by a beetle-mimicking flapping wing system

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Q T; Nguyen, Q V; Park, H C; Goo, N S [Department of Advanced Technology Fusion, Konkuk University, Seoul 143-701 (Korea, Republic of); Truong, V T; Byun, D Y, E-mail: hcpark@konkuk.ac.kr [National Research Laboratory for Biomimetics and Intelligent Microsystems, Konkuk University, Seoul 143-701 (Korea, Republic of)

    2011-09-15

    We present an unsteady blade element theory (BET) model to estimate the aerodynamic forces produced by a freely flying beetle and a beetle-mimicking flapping wing system. Added mass and rotational forces are included to accommodate the unsteady force. In addition to the aerodynamic forces needed to accurately estimate the time history of the forces, the inertial forces of the wings are also calculated. All of the force components are considered based on the full three-dimensional (3D) motion of the wing. The result obtained by the present BET model is validated with the data which were presented in a reference paper. The difference between the averages of the estimated forces (lift and drag) and the measured forces in the reference is about 5.7%. The BET model is also used to estimate the force produced by a freely flying beetle and a beetle-mimicking flapping wing system. The wing kinematics used in the BET calculation of a real beetle and the flapping wing system are captured using high-speed cameras. The results show that the average estimated vertical force of the beetle is reasonably close to the weight of the beetle, and the average estimated thrust of the beetle-mimicking flapping wing system is in good agreement with the measured value. Our results show that the unsteady lift and drag coefficients measured by Dickinson et al are still useful for relatively higher Reynolds number cases, and the proposed BET can be a good way to estimate the force produced by a flapping wing system.

  12. Using robots in "Hands-on" academic activities: a case study examining speech-generating device use and required skills.

    Science.gov (United States)

    Adams, Kim; Cook, Al

    2016-01-01

    A 12-year-old girl, Emily, with complex communication needs and severe physical limitations, controlled a Lego robot from a speech-generating device (SGD) to do various "hands-on" academic activities. Emily's teacher and assistive technology (AT) team thought that controlling a robot would motivate Emily to "use her SGD more". A descriptive case study was used because the integration of communication and manipulation technologies is not yet understood. Target activities and goals were chosen by Emily's teacher and AT team. Emily performed several manipulative math activities and engaged in an "acting" activity aimed at increasing her message length. The competency skills needed to control a robot from the SGD were examined, as well as stakeholder satisfaction with the robot system. Emily generated up to 0.4 communication events and 7 robot commands per minute in the activities. Her length of utterance was usually one-word long, but she generated two- and three-word utterances during some activities. Observations of Emily informed a framework to describe the competency skills needed to use SGDs to control robots. Emily and her teacher expressed satisfaction with robot use. Robot use could motivate students to build SGD operational skills and learn educational concepts. Implications for Rehabilitation Controlling a robot from a speech-generating device (SGD) could increase students' motivation, engagement and understanding in learning educational concepts, because of the hands-on enactive approach. The robot and SGD system was acceptable to the participant and teacher and elicited positive comments from classmates. Thus, it may provide a way for children with disabilities to link with the curriculum and with other students in the classroom. Controlling a robot via SGD presents opportunities to improve augmentative and alternative communication operational, linguistic, social and strategic skills. Careful choice of activities will ensure that the activity requirements

  13. The Effects of Local Heating and Cooling of Arm on Maximal Isometric Force Generated by the Elbow Flexor Musculature in Male Subjects

    Directory of Open Access Journals (Sweden)

    Afsun Nodehi Moghadami

    2012-04-01

    Full Text Available Objectives: It is well known that neuromuscular function is temperature sensitive. Changing of muscle temperature can effect voluntary muscle contraction. The aim of this study was to investigate the effects of cooling and heating on maximal isometric force generated by the elbow flexor musculature in male subjects. Methods: Forty five healthy males encompassing 3 groups participated in the current study. The maximal isometric forces of elbow flexion were measured before and after placing ice and hot packs over the arm for 15 minutes. Paired t tests were used to compare differences between pre and post maximal forces between groups. Results: The results showed no significant difference between pre and post maximal isometric force scores in control and heat groups (P>0.05 and significant difference between pre and post cooling maximal isometric force scores (P=0.02. Discussion: The results suggest that the use of 15 minutes cold pack over the arm can significantly increase muscle force, however, the use of hot pack had no change in force output.

  14. An Examination of AC/HVDC Power Circuits for Interconnecting Bulk Wind Generation with the Electric Grid

    Directory of Open Access Journals (Sweden)

    Daniel Ludois

    2010-06-01

    Full Text Available The application of high voltage dc (HVDC transmission for integrating large scale and/or off-shore wind generation systems with the electric grid is attractive in comparison to extra high voltage (EHV ac transmission due to a variety of reasons. While the technology of classical current sourced converters (CSC using thyristors is well established for realization of large HVDC systems, the technology of voltage sourced converters (VSC is emerging to be an alternative approach, particularly suitable for multi-terminal interconnections. More recently, a more modular scheme that may be termed ‘bridge of bridge’ converters (BoBC has been introduced to realize HVDC systems. While all these three approaches are functionally capable of realizing HVDC systems, the converter power circuit design trade-offs between these alternatives are not readily apparent. This paper presents an examination of these topologies from the point of view of power semiconductor requirements, reactive component requirements, operating losses, fault tolerance, multi-terminal operation, modularity, complexity, etc. Detailed analytical models will be used along with a benchmark application to develop a comparative evaluation of the alternatives that maybe used by wind energy/bulk transmission developers for performing engineering trade-off studies.

  15. EXPERIENCE SANITARY-EPIDEMIOLOGICAL EXAMINATION PROJECT OF PLACING A SOURCE OF IONIZING RADIATION (GENERATING IN HEALTH CARE INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    I. A. Rakitin

    2015-01-01

    Full Text Available The article reviews the results of long-term sanitary-epidemiological examination of projects of placing of ionizing radiation (generating sources in health care institutions of Saint-Petersburg. The majority among the placed sources presented for examination was X-ray diagnostic units and sets – 35.7%, dentist X-rays – 39.4% and fluorography units – 10.8%. Mammography units and computer tomographs made 6.7% each, accelerants – 0.7%.The most frequent reasons of primary refusals to accept design documentation were: absence of calculations of protection against all placed diagnostic X-ray devices (23.6% – at placing of diagnostic X-ray sets, 16.2% – at placing of dentist devices, absence of the upper floors layouts (26.5% – at placing of dentist X-rays and absence of permitting documentation for X-ray devices (at placing of dentist X-ray devices – 22.2%.At carrying out of design activity of special importance is creation of medical and technical projects which were absent in 22.9% of presented projects and in 34.6% were replaced with technical projects. Significant drawbacks of the projects were ignoring the necessity to consider the distance from the personnel workplaces and the width of technical passes (34.0%. That was caused by the absence of corresponding documentation from suppliers of equipment for X-ray rooms.At calculation of protection against X-ray radiation in 11.3% of projects of placing X-ray diagnostic devices (sets and in 7.7% of projects of placing dentist X-ray devices, radiation directivity factors (N were determined incorrectly.Of importance is the issue of adequate choice of building and finishing materials. In 50.0% of projects of placing of diagnostic X-ray devices (sets and 37.6% of projects of placing dentist X-ray devices there were no sanitary-epidemiological conclusions regarding the building and finishing materials to confirming their feasibility for healthcare institutions.Analysis of the main stages

  16. The categorisation of swimming start performance with reference to force generation on the main block and footrest components of the Omega OSB11 start blocks.

    Science.gov (United States)

    Slawson, Sian E; Conway, Paul P; Cossor, Jodi; Chakravorti, Nandini; West, Andrew A

    2013-01-01

    Work presented in this paper provides a methodology for categorising swimming start performance based on peak force production on the main block and footrest components of the Omega OSB11 starting block. A total of 46 elite British swimmers were tested, producing over 1000 start trials. Overwater cameras were synchronised to a specifically designed start block that allowed the measurement of force production via two sets of four, tri-axis, force transducers; one set in the main block and one in the footrest. Data were then analysed, segregating trials for gender. Each start was categorised, with respect to the peak force production in horizontal and vertical components, into one of nine categories. Three performance indicators, i.e. block time, take-off velocity and distance of entry, were used to assess whether differences in performance could be correlated with these categories. Results from these data suggest that swimmers generating higher than average peak forces were more likely to produce a better overall start performance than those who produced forces lower than the average, for this population of athletes.

  17. Muscle strength assessment in critically ill patients with handheld dynamometry: an investigation of reliability, minimal detectable change, and time to peak force generation.

    Science.gov (United States)

    Baldwin, Claire E; Paratz, Jennifer D; Bersten, Andrew D

    2013-02-01

    Dynamometry is an objective tool for volitional strength evaluation that may overcome the limited sensitivity of the Medical Research Council scale for manual muscle tests, particularly at grades 4 and 5. The primary aims of this study were to investigate the reliability, minimal detectable change, and time to peak muscle force, measured with portable dynamometry, in critically ill patients. Isometric hand grip, elbow flexion, and knee extension were measured with portable dynamometry. Interrater consistency (intraclass correlation coefficient [95% confidence interval]) (0.782 [0.321-0.930] to 0.946 [0.840-0.982]) and test-retest agreement (0.819 [0.390-0.943] to 0.918 [0.779-0.970]) were acceptable for all dynamometry forces, with the exception of left elbow flexion. Despite generally good reliability, a mean change (upper 95% confidence interval) of 2.8 (7.8) kg, 1.9 (5.2) kg, and 2.6 (7.1) kg may be required from a patient's baseline force measurement of right grip, elbow flexion, and knee extension to reflect real force changes. There was also a delay in the time for critically ill patients to generate peak muscle forces, compared with healthy controls (P ≤ .001). Dynamometry can provide reliable measurements in alert critically ill patients, but moderate changes in strength may be required to overcome measurement error, during the acute recovery period. Deficits in force timing may reflect impaired neuromuscular control. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. The evolution of radiation dose over time: Measurement of a patient cohort undergoing whole-body examinations on three computer tomography generations

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, Roy P., E-mail: roy.marcus@med.uni-tuebingen.de [Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen (Germany); Department of Radiology, Mayo Clinic, Rochester, MN (United States); Koerner, Elise [Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen (Germany); Aydin, Roland C. [Institute for Computational Mechanics, Technische Universität München, Garching (Germany); Zinsser, Dominik; Finke, Tobias [Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen (Germany); Cyron, Christian J. [Institute for Computational Mechanics, Technische Universität München, Garching (Germany); Bamberg, Fabian; Nikolaou, Konstantin; Notohamiprodjo, Mike [Institute of Diagnostic and Interventional Radiology, Eberhard-Karls-Universität, Tübingen (Germany)

    2017-01-15

    Objectives: To evaluate and compare the radiation dose and image quality of whole-body-CT (WBCT) performed on the 3rd-generation dual-source-CT (DSCT) with 2nd-generation DSCT and 64-slices-Single-Source-CT (SSCT) in a large patient cohort. Material and methods: Using a monitoring and tracking software 1451, 747 and 1861 patients scanned with a one-spiral-thorax-abdomen-pelvis-CT-examination on a 3rd-, 2nd-generation DSCT and SSCT, respectively, were extracted from the PACS server. For the intra-individual analysis, 203 patients on the 3rd-generation DSCT were identified. Out of those 203 patients, 155 had the same examination on the 2nd-generation DSCT, 91 patients had the same examination on the SSCT and 43 patients had an examination on all three CT-generations. Automatic tube current modulation was active on all three CT-generations, whereas automatic tube voltage selection was only available on both DSCT-generations. Dose was recorded by the size-specific-dose-estimate-method (SSDE); signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated placing a ROI on the ascending aorta/liver and the subcutaneous adipose tissue at comparable level. Image quality of axillary and mediastinal lymph nodes and adrenal glands was assessed by two experienced radiologists. Results: Subjective image quality was excellent throughout all three CT-generations (p = 0.38–0.98). Quantitative image quality in both DSCT generations was superior to SSCT (p < 0.001). SNR and CNR in the liver parenchyma were superior in the 3rd-generation DSCT compared to the 2nd generation DSCT (p < 0.001), whereas there was no difference in the aorta. In the inter-individual analysis, CTDI{sub vol} was lower by 26.9% and 44.3% in the 3rd-generation DSCT, when compared to the 2nd-generation DSCT and SSCT, respectively; SSDE was lower by 31.5% and 51% in the 3rd-generation DSCT, when compared to the 2nd-generation DSCT and SSCT, respectively. In the intra-individual comparison CTDI

  19. The effects of cutting parameters on cutting forces and heat generation when drilling animal bone and biomechanical test materials.

    Science.gov (United States)

    Cseke, Akos; Heinemann, Robert

    2018-01-01

    The research presented in this paper investigated the effects of spindle speed and feed rate on the resultant cutting forces (thrust force and torque) and temperatures while drilling SawBones ® biomechanical test materials and cadaveric cortical bone (bovine and porcine femur) specimens. It also investigated cortical bone anisotropy on the cutting forces, when drilling in axial and radial directions. The cutting forces are only affected by the feed rate, whereas the cutting temperature in contrast is affected by both spindle speed and feed rate. The temperature distribution indicates friction as the primary heat source, which is caused by the rubbing of the tool margins and the already cut chips over the borehole wall. Cutting forces were considerably higher when drilling animal cortical bone, in comparison to cortical test material. Drilling direction, and therewith anisotropy, appears to have a negligible effect on the cutting forces. The results suggest that this can be attributed to the osteons being cut at an angle rather than in purely axial or radial direction, as a result of a twist drill's point angle. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  20. A Current-Forced Line-Commutated Inverter for Single-Phase Grid-Connected Photovoltaic Generation Systems

    Directory of Open Access Journals (Sweden)

    UNLU, M.

    2015-05-01

    Full Text Available A simple power electronic interface based on the line-commutated inverter (LCI has been developed in order to inject sinusoidal current to the grid for single-phase grid-connected photovoltaic (PV energy generation systems. The proposed inverter facilitates controlling the injecting/grid current with a controllable power factor in contrast to the conventional LCI system. It is achieved that the total harmonic distortion (THD of the injecting currents for the different firing angles/power factors and reference currents is about 5% or less than 5%. Thus, the grid-connected standards for injecting current are satisfied without filter equipment unlike the conventional LCI system. The proposed system has been built in MATLAB/Simulink and examined experimentally on PV array of 160 W. The simulation and experimental results are better performance than the conventional line-commutated inverter methods reported in the literature. The proposed LCI has a simple and robust structure, and it can be easily synchronized with grid thanks to self-latching property of SCRs. Therefore, it is a good alternative for the power transferring from PV panels to the utility grid in grid-connected PV systems.

  1. The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

    Science.gov (United States)

    Turcato, Anna Maria; Godi, Marco; Giordano, Andrea; Schieppati, Marco; Nardone, Antonio

    2015-01-09

    Turning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking. Twenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination. Gait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In. The lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet

  2. Bra-breast forces generated in women with large breasts while standing and during treadmill running: Implications for sports bra design.

    Science.gov (United States)

    McGhee, Deirdre E; Steele, Julie R; Zealey, William J; Takacs, George J

    2013-01-01

    This study aimed to determine the bra-breast forces generated in women with large breasts while these women wore different levels of breast support during both upright standing and treadmill running. The mean bilateral vertical component of the bra-breast force in standing was 11.7 ± 4.6 N, whereas during treadmill running the mean unilateral bra-breast force was 8.7 ± 6.4 N and 14.7 ± 10.3 N in the high and low support conditions, respectively. Furthermore, breast mass was significantly correlated with vertical breast displacement (R(2) = 0.62) in the high support condition. The wide range of breast masses of women with large breasts is an important consideration for designers of sports bras to ensure these bras can reduce force generation and breast discomfort by providing a high level of breast support while these women participate in physical activity. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  3. Hyperthermophile protein behavior: partially-structured conformations of Pyrococcus furiosus rubredoxin monomers generated through forced cold-denaturation and refolding.

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Chandrayan

    Full Text Available Some years ago, we showed that thermo-chemically denatured, partially-unfolded forms of Pyrococcus furiosus triosephosphateisomerase (PfuTIM display cold-denaturation upon cooling, and heat-renaturation upon reheating, in proportion with the extent of initial partial unfolding achieved. This was the first time that cold-denaturation was demonstrated for a hyperthermophile protein, following unlocking of surface salt bridges. Here, we describe the behavior of another hyperthermophile protein, the small, monomeric, 53 residues-long rubredoxin from Pyrococcus furiosus (PfRd, which is one of the most thermostable proteins known to man. Like PfuTIM, PfRd too displays cold-denaturation after initial thermo-chemical perturbation, however, with two differences: (i PfRd requires considerably higher temperatures as well as higher concentrations of guanidium hydrochloride (Gdm.HCl than PfuTIM; (ii PfRd's cold-denaturation behavior during cooling after thermo-chemical perturbation is incompletely reversible, unlike PfuTIM's, which was clearly reversible (from each different conformation generated. Differential cold-denaturation treatments allow PfRd to access multiple partially-unfolded states, each of which is clearly highly kinetically-stable. We refer to these as 'Trishanku' unfolding intermediates (or TUIs. Fascinatingly, refolding of TUIs through removal of Gdm.HCl generates multiple partially-refolded, monomeric, kinetically-trapped, non-native 'Trishanku' refolding intermediates (or TRIs, which differ from each other and from native PfRd and TUIs, in structural content and susceptibility to proteolysis. We find that the occurrence of cold denaturation and observations of TUI and TRI states is contingent on the oxidation status of iron, with redox agents managing to modulate the molecule's behavior upon gaining access to PfRd's iron atom. Mass spectrometric examination provides no evidence of the formation of disulfide bonds, but other experiments

  4. Improved contractile force generation of tissue-engineered skeletal muscle constructs by IGF-I and Bcl-2 gene transfer with electrical pulse stimulation

    OpenAIRE

    Ikeda, Kazushi; Ito, Akira; Sato, Masanori; Kawabe, Yoshinori; Kamihira, Masamichi

    2016-01-01

    Introduction: Tissue-engineered skeletal muscle constructs should be designed to generate contractile force with directional movement. Because electrical impulses from a somatic nervous system are crucial for in vivo skeletal muscle development, electrical pulse stimulation (EPS) culture as an artificial exercise is essential to fabricate functional skeletal muscle tissues in vitro. To further improve muscle functions, the activation of cell-signaling pathways from myogenic growth factors, su...

  5. Dissipative particle dynamics simulation of flow generated by two rotating concentric cylinders: II. Lateral dissipative and random forces

    International Nuclear Information System (INIS)

    Filipovic, N; Haber, S; Kojic, M; Tsuda, A

    2008-01-01

    Traditional DPD methods address dissipative and random forces exerted along the line connecting neighbouring particles. Espanol (1998 Phys. Rev. E 57 2930-48) suggested adding dissipative and random force components in a direction perpendicular to this line. This paper focuses on the advantages and disadvantages of such an addition as compared with the traditional DPD method. Our benchmark system comprises fluid initially at rest occupying the space between two concentric cylinders rotating with various angular velocities. The effect of the lateral force components on the time evolution of the simulated velocity profile was also compared with that of the known analytical solution. The results show that (i) the solution accuracy at steady state has improved and the error has been reduced by at least 30% (in one case by 75%), (ii) the DPD time to reach steady state has been halved, (iii) the CPU time has increased by only 30%, and (iv) no significant differences exist in density and temperature distributions

  6. Comparing Single Case Design Overlap-Based Effect Size Metrics from Studies Examining Speech Generating Device Interventions

    Science.gov (United States)

    Chen, Mo; Hyppa-Martin, Jolene K.; Reichle, Joe E.; Symons, Frank J.

    2016-01-01

    Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with…

  7. Chin force in violin playing.

    Science.gov (United States)

    Obata, Satoshi; Kinoshita, Hiroshi

    2012-06-01

    Force generated between the left mandible of violinists and the chinrest of the violin was examined using a force-sensing chinrest developed in this study. A strain-gauge force sensor was built, and it was fixed between the violin's top plate and a chin cup. Fifteen professional/amateur violinists held the violin statically, played musical scales with different sound properties and sounding techniques, as well as an excerpt from a Max Bruch concerto. Peak and mean forces were evaluated for each task. In a separate experiment, lateral movement of the lower teeth due to different levels of voluntary chin force exertion was measured. Static holding forces observed were 15 and 22 N with and without the help of the left hand, respectively. Peak force increased from 16 N at soft dynamics to 20 N at strong dynamics during scales. The force further increased to 29 N with the use of vibrato technique and 35 N during shifts. Tempo and hand position did not affect the force. Playing a Bruch concerto induced a mean peak force of 52 N, ranging from 31 to 82 N among the violinists. The developed force-sensing chinrest could accurately record the generated chin force. Typical chin force to stabilize the violin during ordinary musical performance was less than 30 N, but it could momentarily exceed 50 N when technically demanding musical pieces were performed. The lateral shift of the mandible was fairly small (<0.4 mm) even with high chin-force exertion, possibly due to clenching of the molars.

  8. Up-regulation of Rho/ROCK signaling in sarcoma cells drives invasion and increased generation of protrusive forces

    Czech Academy of Sciences Publication Activity Database

    Rosel, D.; Brabek, J.; Tolde, O.; Mierke, C.T.; Zitterbart, D.P.; Raupach, C.; Bicanova, K.; Kollmannsberger, P.; Pánková, D.; Veselý, Pavel; Folk, P.; Fabry, B.

    2008-01-01

    Roč. 6, č. 9 (2008), s. 1410-1420 ISSN 1541-7786 Institutional research plan: CEZ:AV0Z50520514 Keywords : Rho kinase ROCK * traction force microscopy * ameboid invasion Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.533, year: 2008

  9. A multiscale chemo-electro-mechanical skeletal muscle model to analyze muscle contraction and force generation for different muscle fiber arrangements

    Directory of Open Access Journals (Sweden)

    Thomas eHeidlauf

    2014-12-01

    Full Text Available The presented chemo-electro-mechanical skeletal muscle model relies on a continuum mechanical formulation describing the muscle’s deformation and force generation on the macroscopic muscle level. Unlike other three-dimensional models, the description of the activation-induced behavior of the mechanical model is entirely based on chemo-electro-mechanical principles on the microscopic sarcomere level. Yet, the multiscale model reproduces key characteristics of skeletal muscles such as experimental force-length and force-velocity data on the macroscopic whole muscle level. The paper presents the methodological approaches required to obtain such a multiscale model, and demonstrates the feasibility of using such a model to analyze differences in the mechanical behavior of parallel-fibered muscles, in which the muscle fibers either span the entire length of the fascicles or terminate intrafascicularly. The presented results reveal that muscles, in which the fibers span the entire length of the fascicles, show lower peak forces, more dispersed twitches and fusion of twitches at lower stimulation frequencies. In detail, the model predicted twitch rise times of 38.2ms and 17.2ms for a 12 cm long muscle, in which the fibers span the entire length of the fascicles and with twelve fiber compartments in series, respectively. Further, the twelve-compartment model predicted peak twitch forces that were 19% higher than in the single-compartment model. The analysis of sarcomere lengths during fixed-end single twitch contractions at optimal length predicts rather small sarcomere length changes. The observed lengths range from 75 to 111% of the optimal sarcomere length, which corresponds to a region with maximum filament overlap. This result suggests that stability issues resulting from activation-induced stretches of non-activated sarcomeres are unlikely in muscles with passive forces appearing at short muscle length.

  10. A Generational Examination of Instructional Facebook Use and the Effects on Perceived Instructor Immediacy, Credibility and Student Affective Learning

    Science.gov (United States)

    Enskat, Aaron; Hunt, Stephen K.; Hooker, John F.

    2017-01-01

    This study examined Millennial student perceptions of use of social networking, specifically Facebook, by instructors. Two independent variables were examined: instructor age (Baby Boomer or Millennial) and use of Facebook (utilising a course group site through the service versus not using the service at all). Results revealed that Baby Boomer…

  11. Differential thermodynamic driving force of first- and second-generation antihistamines to determine their binding affinity for human H1 receptors.

    Science.gov (United States)

    Hishinuma, Shigeru; Sugawara, Kenta; Uesawa, Yoshihiro; Fukui, Hiroyuki; Shoji, Masaru

    2014-09-15

    Differential binding sites for first- and second-generation antihistamines were indicated on the basis of the crystal structure of human histamine H1 receptors. In this study, we evaluated differences between the thermodynamic driving forces of first- and second-generation antihistamines for human H1 receptors and their structural determinants. The binding enthalpy and entropy of 20 antihistamines were estimated with the van't Hoff equation using their dissociation constants obtained from their displacement curves against the binding of [(3)H]mepyramine to membrane preparations of Chinese hamster ovary cells expressing human H1 receptors at various temperatures from 4°C to 37°C. Structural determinants of antihistamines for their thermodynamic binding properties were assessed by quantitative structure-activity relationship (QSAR) analyses. We found that entropy-dependent binding was more evident in second- than first-generation antihistamines, resulting in enthalpy-entropy compensation between the binding forces of first- and second-generation antihistamines. QSAR analyses indicated that enthalpy-entropy compensation was determined by the sum of degrees, maximal electrostatic potentials, water-accessible surface area and hydrogen binding acceptor count of antihistamines to regulate their affinity for receptors. In conclusion, it was revealed that entropy-dependent hydrophobic interaction was more important in the binding of second-generation antihistamines, even though the hydrophilicity of second-generation antihistamines is generally increased. Furthermore, their structural determinants responsible for enthalpy-entropy compensation were explored by QSAR analyses. These findings may contribute to understanding the fundamental mechanisms of how the affinity of ligands for their receptors is regulated. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. An analysis of laminar free-convection flow and heat transfer about a flat plate paralled to the direction of the generating body force

    Science.gov (United States)

    Ostrach, Simon

    1953-01-01

    The free-convection flow and heat transfer (generated by a body force) about a flat plate parallel to the direction of the body force are formally analyzed and the type of flow is found to be dependent on the Grashof number alone. For large Grashof numbers (which are of interest in aeronautics), the flow is of the boundary-layer type and the problem is reduced in a formal manner, which is analogous to Prandtl's forced-flow boundary-layer theory, to the simultaneous solution of two ordinary differential equations subject to the proper boundary conditions. Velocity and temperature distributions for Prandtl numbers of 0.01, 0.72, 0.733, 1, 1, 10, 100, and 1000 are computed, and it is shown that velocities and Nusselt numbers of the order of magnitude of those encountered in forced-convection flows may be obtained in free-convection flows. The theoretical and experimental velocity and temperature distributions are in good agreement. A flow and a heat-transfer parameter, from which the important physical quantities such as shear stress and heat-transfer rate can be computed, are derived as functions of Prandtl number alone.

  13. "Desafios y Bendiciones": A Multiperspective Examination of the Educational Experiences and Coping Responses of First-Generation College Latina Students

    Science.gov (United States)

    Gloria, Alberta M.; Castellanos, Jeanett

    2012-01-01

    Taking a multiperspective approach, seven Latina students, two student services personnel, and one mental health service provider are interviewed to gain different stakeholder perspectives regarding Latina first-generation college educational and coping experiences. Familial involvement and connections with family, peers, and university personnel…

  14. Flagella-generated forces reveal gear-type motor in single cells of the green alga, Chlamydomonas reinhardtii.

    Science.gov (United States)

    D'Souza, Jacinta S; Gudipati, Mohanram; Dharmadhikari, Jayashree A; Dharmadhikari, Aditya K; Kashyap, Abhishek; Sivaramakrishnan, Manaswini; Aiyer, Manaswini; Rao, Usha; Mathur, Deepak; Rao, Basuthkar J

    2009-03-06

    Optically trapped single cells of the biflagellated, green alga, Chlamydomonas reinhardtii, rotate. The rotational dynamics of trapped wild-type and mutant cells show that functional flagella play a decisive role: the entire flagellar apparatus (central microtubules, radial spokes, and dynein arms) is involved. Any aberration in this apparatus leads to non-functionality, indicating a gear-type mechanism. The translational and rotational motions of the wild-type and mutant cells do not differ significantly. Optical forces alone do not play a vital role in the rotational dynamics of this cellular motor, making them useful as probes of the internal dynamics without external influence.

  15. [Measurements of the flux densities of static magnetic fields generated by two types of dental magnetic attachments and their retentive forces].

    Science.gov (United States)

    Xu, Chun; Chao, Yong-lie; Du, Li; Yang, Ling

    2004-05-01

    To measure and analyze the flux densities of static magnetic fields generated by two types of commonly used dental magnetic attachments and their retentive forces, and to provide guidance for the clinical application of magnetic attachments. A digital Gaussmeter was used to measure the flux densities of static magnetic fields generated by two types of magnetic attachments, under four circumstances: open-field circuit; closed-field circuit; keeper and magnet slid laterally for a certain distance; and existence of air gap between keeper and magnet. The retentive forces of the magnetic attachments in standard closed-field circuit, with the keeper and magnet sliding laterally for a certain distance or with a certain air gap between keeper and magnet were measured by a tensile testing machine. There were flux leakages under both the open-field circuit and closed-field circuit of the two types of magnetic attachments. The flux densities on the surfaces of MAGNEDISC 800 (MD800) and MAGFIT EX600W (EX600) magnetic attachments under open-field circuit were 275.0 mT and 147.0 mT respectively. The flux leakages under closed-field circuit were smaller than those under open-field circuit. The respective flux densities on the surfaces of MD800 and EX600 magnetic attachments decreased to 11.4 mT and 4.5 mT under closed-field circuit. The flux density around the magnetic attachment decreased as the distance from the surface of the attachment increased. When keeper and magnet slid laterally for a certain distance or when air gap existed between keeper and magnet, the flux leakage increased in comparison with that under closed-field circuit. Under the standard closed-field circuit, the two types of magnetic attachments achieved the largest retentive forces. The retentive forces of MD800 and EX600 magnetic attachments under the standard closed-field circuit were 6.20 N and 4.80 N respectively. The retentive forces decreased with the sliding distance or with the increase of air gap

  16. Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

    Directory of Open Access Journals (Sweden)

    Manoela Fávaro Francisconi

    Full Text Available ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342, using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05. Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

  17. Arrhythmia-free survival and pulmonary vein reconnection patterns after second-generation cryoballoon and contact-force radiofrequency pulmonary vein isolation.

    Science.gov (United States)

    Buist, Thomas J; Adiyaman, Ahmet; Smit, Jaap Jan J; Ramdat Misier, Anand R; Elvan, Arif

    2018-02-06

    The aim of this study was to compare second-generation cryoballoon and contact-force radiofrequency point-by-point pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients with regard to pulmonary vein reconnection and arrhythmia-free survival. Altogether, 269 consecutive patients with drug-refractory AF undergoing PVI were included and randomly allocated to second-generation cryoballoon or contact-force point-by-point radiofrequency ablation. Median follow-up duration was 389 days (interquartile range 219-599). Mean age was 59 years (71% male); 136 patients underwent cryoballoon and 133 patients underwent radiofrequency ablation. Acute electrical PVI was 100% for both techniques. Procedure duration was significantly shorter in cryoballoon vs radiofrequency (166.5 vs 184.13 min P = 0.016). Complication rates were similar (6.0 vs 6.7%, P = 1.00). Single procedure freedom of atrial arrhythmias was significantly higher in cryoballoon as compared to radiofrequency (75.2 vs 57.4%, P = 0.013). In multivariate analysis, persistent AF, AF duration, and cryoballoon ablation were associated with freedom of atrial tachyarrhythmias. The number of repeat ablation procedures was significantly lower in the cryoballoon compared to radiofrequency (15.0 vs 24.3%, P = 0.045). At repeat ablation, pulmonary vein reconnection rate was significantly lower after cryoballoon as compared to radiofrequency ablation (36.8 vs 58.1%, P = 0.003). Improved arrhythmia-free survival and more durable pulmonary vein isolation is seen after PVI using second-generation cryoballoon as compared to contact-force radiofrequency, in patients with drug-refractory paroxysmal AF. Complication rates for both ablation techniques are low.

  18. GENERATION OF A PROTON MOTIVE FORCE BY HISTIDINE DECARBOXYLATION AND ELECTROGENIC HISTIDINE HISTAMINE ANTIPORT IN LACTOBACILLUS-BUCHNERI

    NARCIS (Netherlands)

    MOLENAAR, D; BOSSCHER, JS; TENBRINK, B; DRIESSEN, AJM; KONINGS, WN

    Lactobacillus buchneri ST2A vigorously decarboxylates histidine to the biogenic amine histamine, which is excreted into the medium. Cells grown in the presence of histidine generate both a transmembrane pH gradient, inside alkaline, and an electrical potential (DELTApsi), inside negative, upon

  19. EXAMINATION OF THE CUTTING FORCES OF AISI 304 AUSTENITIC STAINLESS STEEL IN THE TURNING PROCESS WITH TITANIUM CARBIDE COATED CUTTING TOOLS

    Directory of Open Access Journals (Sweden)

    Özgür TEKASLAN

    2007-02-01

    Full Text Available In this study, cutting forces occurring in the machining process of AISI 304 austenitic stainless steel specimen using titanium coated cutting tools are investigated experimentally and the results are compared to theoretical calculations. In the experimental study, various cutting speeds, feed rates and cutting depths are considered. Cutting forces are measured by 3-dimensional Kistler dynamometer. In the theoretically study, cutting forces are determined by Kienzle formulation. Consequently, it is found that the calculation of cutting forces in the theoretical method doesn't yield the exact results because of various factors and there is a % 25 average differences in accordance with the experimental results. Hence it is evaluated that the experimental technique in the determination of cutting forces yields more accurate results.

  20. Changes in power and force generation during coupled eccentric-concentric versus concentric muscle contraction with training and aging

    DEFF Research Database (Denmark)

    Caserotti, Paolo; Aagaard, Per; Puggaard, Lis

    2008-01-01

    Age-related decline in maximal concentric muscle power is associated with frailty and functional impairments in the elderly. Compared to concentric contraction, mechanical muscle output is generally enhanced when muscles are rapidly pre-stretched (eccentric contraction), albeit less pronounced......-alone and coupled eccentric-concentric contraction and selected functional motor performances before and after 36-week multicomponent training including aerobic, strength, balance, flexibility and coordination components in elderly males. Vertical force, excursion, velocity, power and acceleration of the body...... center of mass were measured in two standardised vertical jumps (squatting jump, SQJ; countermovement jump, CMJ). Pre-stretch enhancement during CMJ did not improve performance [i.e., no enhanced maximal muscle power (P (peak)) and jump height (JH)] compared to concentric-alone muscle contraction (SQJ...

  1. Sexual orientation differences in teen pregnancy and hormonal contraceptive use: an examination across 2 generations

    OpenAIRE

    Charlton, Brittany Michelle; Corliss, Heather L.; Missmer, Stacey Ann; Rosario, Margaret; Spiegelman, Donna Lynn; Austin, Sydney Bryn

    2013-01-01

    OBJECTIVE: To examine whether sexual orientation is associated with disparities in teen pregnancy and hormonal contraception use among adolescent females in 2 intergenerational cohorts. STUDY DESIGN: Data were collected from 91,003 women in the Nurses' Health Study II (NHSII), born between 1947-1964, and 6463 of their children, born between 1982-1987, enrolled in the Growing Up Today Study (GUTS). Log-binomial models were used to estimate risk ratios for teen pregnancy and hormonal ...

  2. An Examination of the Roles of Medical Units in Support of Chemical, Biological, Radiological, or Nuclear Event (CBRN) under Joint Task Force Civil Support (JF-CS)

    Science.gov (United States)

    2012-05-16

    diabetes, obesity, pediatrics, geriatrics , obstetrics, are some of the areas that the military medical response forces are currently not capable of...equipment and maintenance thereof; combat stress control; and medical, dental, veterinary, laboratory, optometric, nutrition therapy, and medical...

  3. Enhancement of Force Generated by Individual Myosin Heads in Skinned Rabbit Psoas Muscle Fibers at Low Ionic Strength

    OpenAIRE

    Sugi, Haruo; Abe, Takahiro; Kobayashi, Takakazu; Chaen, Shigeru; Ohnuki, Yoshiki; Saeki, Yasutake; Sugiura, Seiryo

    2013-01-01

    Although evidence has been presented that, at low ionic strength, myosin heads in relaxed skeletal muscle fibers form linkages with actin filaments, the effect of low ionic strength on contraction characteristics of Ca(2+)-activated muscle fibers has not yet been studied in detail. To give information about the mechanism of muscle contraction, we have examined the effect of low ionic strength on the mechanical properties and the contraction characteristics of skinned rabbit psoas muscle fiber...

  4. Methodology and a preliminary data base for examining the health risks of electricity generation from uranium and coal fuels

    Energy Technology Data Exchange (ETDEWEB)

    El-Bassioni, A.A.

    1980-08-01

    An analytical model was developed to assess and examine the health effects associated with the production of electricity from uranium and coal fuels. The model is based on a systematic methodology that is both simple and easy to check, and provides details about the various components of health risk. A preliminary set of data that is needed to calculate the health risks was gathered, normalized to the model facilities, and presented in a concise manner. Additional data will become available as a result of other evaluations of both fuel cycles, and they should be included in the data base. An iterative approach involving only a few steps is recommended for validating the model. After each validation step, the model is improved in the areas where new information or increased interest justifies such upgrading. Sensitivity analysis is proposed as the best method of using the model to its full potential. Detailed quantification of the risks associated with the two fuel cycles is not presented in this report. The evaluation of risks from producing electricity by these two methods can be completed only after several steps that address difficult social and technical questions. Preliminary quantitative assessment showed that several factors not considered in detail in previous studies are potentially important. 255 refs., 21 figs., 179 tabs.

  5. The Next Generation of Scientists: Examining the Experiences of Graduate Students in Network-Level Social-Ecological Science

    Directory of Open Access Journals (Sweden)

    Michele Romolini

    2013-09-01

    Full Text Available By integrating the research and resources of hundreds of scientists from dozens of institutions, network-level science is fast becoming one scientific model of choice to address complex problems. In the pursuit to confront pressing environmental issues such as climate change, many scientists, practitioners, policy makers, and institutions are promoting network-level research that integrates the social and ecological sciences. To understand how this scientific trend is unfolding among rising scientists, we examined how graduate students experienced one such emergent social-ecological research initiative, Integrated Science for Society and Environment, within the large-scale, geographically distributed Long Term Ecological Research (LTER Network. Through workshops, surveys, and interviews, we found that graduate students faced challenges in how they conceptualized and practiced social-ecological research within the LTER Network. We have presented these conceptual challenges at three scales: the individual/project, the LTER site, and the LTER Network. The level of student engagement with and knowledge of the LTER Network was varied, and students faced different institutional, cultural, and logistic barriers to practicing social-ecological research. These types of challenges are unlikely to be unique to LTER graduate students; thus, our findings are relevant to other scientific networks implementing new social-ecological research initiatives.

  6. Modelling the driving forces of the municipal solid waste generation in touristic islands. A case study of the Balearic Islands (2000-2030).

    Science.gov (United States)

    Estay-Ossandon, Charles; Mena-Nieto, Angel

    2018-02-14

    The improvement of municipal solid waste (MSW) management in touristic islands has not been sufficiently studied, and by using the Spanish Balearics as a case study, a hybrid methodology has been developed which: (i) identifies the three most influential variables (driving forces) of the MSW generation system through an econometric model based on official historical data for a given period (2000-2014), (ii) develops a System Dynamics (SD) model of the evolution of MSW generation in this archipelago based on the same data and time period, and (iii) forecasts the performance of the MSW management system for a future period (2015-2030). Six different scenarios are considered with varying assumptions, objectives and management policies, while applying Scenario Analysis to the SD model developed. The results show that by maintaining the current policies ("business as usual" BAU scenario) it will be impossible to meet the goals set by the Regional and the Spanish National Plans based on the European MSW Directive. However, by implementing the improvements proposed in the simulated alternative scenarios, the model predicts that by 2030, generation of MSW will have increased by 15% compared to 2014, mainly due to the effect of the Tourist Population which is 37.5% higher than the Resident Population. In addition, for the most optimistic scenario, the amount of MSW sent to landfills would decrease by 40%, and selective collection would increase by 30%, compared to 2014. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Filament turnover tunes both force generation and dissipation to control long-range flows in a model actomyosin cortex.

    Science.gov (United States)

    McFadden, William M; McCall, Patrick M; Gardel, Margaret L; Munro, Edwin M

    2017-12-01

    Actomyosin-based cortical flow is a fundamental engine for cellular morphogenesis. Cortical flows are generated by cross-linked networks of actin filaments and myosin motors, in which active stress produced by motor activity is opposed by passive resistance to network deformation. Continuous flow requires local remodeling through crosslink unbinding and and/or filament disassembly. But how local remodeling tunes stress production and dissipation, and how this in turn shapes long range flow, remains poorly understood. Here, we study a computational model for a cross-linked network with active motors based on minimal requirements for production and dissipation of contractile stress: Asymmetric filament compliance, spatial heterogeneity of motor activity, reversible cross-links and filament turnover. We characterize how the production and dissipation of network stress depend, individually, on cross-link dynamics and filament turnover, and how these dependencies combine to determine overall rates of cortical flow. Our analysis predicts that filament turnover is required to maintain active stress against external resistance and steady state flow in response to external stress. Steady state stress increases with filament lifetime up to a characteristic time τm, then decreases with lifetime above τm. Effective viscosity increases with filament lifetime up to a characteristic time τc, and then becomes independent of filament lifetime and sharply dependent on crosslink dynamics. These individual dependencies of active stress and effective viscosity define multiple regimes of steady state flow. In particular our model predicts that when filament lifetimes are shorter than both τc and τm, the dependencies of effective viscosity and steady state stress on filament turnover cancel one another, such that flow speed is insensitive to filament turnover, and shows a simple dependence on motor activity and crosslink dynamics. These results provide a framework for understanding

  8. DEEPWAVE Initial Investigation of Mesospheric Gravity Wave Signatures Generated by Variable Orographic Forcing Over Lauder Station (45°S). New Zealand

    Science.gov (United States)

    Criddle, N.; Taylor, M. J.; Pautet, P. D.; Zhao, Y.

    2014-12-01

    DEEPWAVE is a new international collaborative research program focused on identifying, characterizing, and predicting the generation and propagation of deeply propagating atmospheric gravity waves from the Earth's surface up to ̴100 km altitude and beyond. An extended series of coordinated airborne and ground-based measurements were recently conducted from New Zealand's South Island to investigate gravity wave forcing during the winter months when strong North-Westerly winds are known to generate gravity waves capable of penetrating well into the stratosphere. As part of this collaborative effort the Atmospheric Imaging Lab at Utah State University (USU) deployed and operated an Advanced Mesospheric Temperature Mapper (AMTM) at the National Institute for Water and Atmosphere (NIWA) Lauder research station, NZ (45°S 169°E). In the lee of the Southern Alps, Lauder is well positioned for measuring a broad spectrum of gravity waves launched from south island orography and from other meteorological sources. The AMTM is uniquely capable of mapping the wave-induced temperature perturbations to investigate the two-dimensional gravity wave field with high temporal ( ̴10 sec) and high temperature precision ( ̴1-2 K in 30 sec). High-quality infrared image measurements of the OH (3,1) band emission layer (altitude ̴ 87 km) were made nightly from May 31 to July 22, 2014. The DEEPWAVE program has been a resounding success and over 42 nights of data were obtained at Lauder with distinct mesospheric mountain wave signatures recorded there in OH intensity, and in temperatures for the first time. In this poster we provide a summary of the AMTM data set from Lauder, complemented by data from coincident airborne over-flights where appropriate, and we present initial results characterizing the mesopause gravity wave field under varying orographic forcings. We thank the NSF for sponsoring this research program.

  9. Evaluating Photographs as a Replacement for the In-Person Physical Examination of the Scored Patient-Generated Subjective Global Assessment in Elderly Hospital Patients.

    Science.gov (United States)

    Miller, Michelle; Thomas, Jolene; Suen, Jenni; Ong, De Sheng; Sharma, Yogesh

    2018-02-08

    Undernourished patients discharged from the hospital require follow-up; however, attendance at return visits is low. Teleconsultations may allow remote follow-up of undernourished patients; however, no valid method to remotely perform physical examination, a critical component of assessing nutritional status, exists. This study aims to compare agreement between photographs taken by trained dietitians and in-person physical examinations conducted by trained dietitians to rate the overall physical examination section of the scored Patient Generated Subjective Global Assessment (PG-SGA). Nested cross-sectional study. Adults aged ≥60 years, admitted to the general medicine unit at Flinders Medical Centre between March 2015 and March 2016, were eligible. All components of the PG-SGA and photographs of muscle and fat sites were collected from 192 participants either in the hospital or at their place of residence after discharge. Validity of photograph-based physical examination was determined by collecting photographic and PG-SGA data from each participant at one encounter by trained dietitians. A dietitian blinded to data collection later assessed de-identified photographs on a computer. Percentage agreement, weighted kappa agreement, sensitivity, and specificity between the photographs and in-person physical examinations were calculated. All data collected were included in the analysis. Overall, the photograph-based physical examination rating achieved a percentage agreement of 75.8% against the in-person assessment, with a weighted kappa agreement of 0.526 (95% CI: 0.416, 0.637; Pphysical examination by trained dietitians achieved a nearly acceptable percentage agreement, moderate weighted kappa, and fair sensitivity-specificity pair. Methodological refinement before field testing with other personnel may improve the agreement and accuracy of photograph-based physical examination. Copyright © 2018 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All

  10. Atomic force microscopy investigation of surface roughness generated between SiO2 micro-pits in CHF3/Ar plasma

    Science.gov (United States)

    Rad, Maryam Alsadat; Ibrahim, Kamarulazizi; Mohamed, Khairudin

    2012-05-01

    The present paper investigates the surface roughness generated by reactive ion etching (RIE) on the location between silicon dioxide (SiO2) micro-pits structures. The micro-pit pattern on polymethyl methacrylate (PMMA) mask was created by an electron beam lithography tool. By using PMMA as a polymer resist mask layer for pattern transfer in RIE process, the carbon (C) content in etching process is increased, which leads to decrease of F/C ratio and causes domination of polymerization reactions. This leads to high surface roughness via self-organized nanostructure features generated on SiO2 surface which was analyzed using atomic force microscopy (AFM) technique. The etching chemistry of CHF3 plasma on PMMA masking layer and SiO2 is analyzed to explain the polymerization. The surface root-mean-square (RMS) roughness below 1 nm was achieved by decreasing the RF power to 150 W and process pressure lower than 10 mTorr.

  11. Consumer-generated Advertising on YouTube : A quantitative study examining the effects of endorser credibility and coupon proneness on brands

    OpenAIRE

    Jonsson Brajim, Rahel; Romanov, Tina

    2016-01-01

    Consumer-generated advertising on YouTube is a developing phenomenon that in the last years has grown exponentially. Recent research by Holt (2016) suggests that well-known content creators on YouTube have a large impact on brands, so great that regular firms are unable to compete with these well-known content creators. However, firms do have the opportunity to cooperate with well-known content creators on YouTube. Therefore, examining YouTube as a marketing tool is beneficial for marketing m...

  12. Comparative efficacy and safety of contact force-sensing catheter and second-generation cryoballoon ablation for atrial fibrillation: a meta-analysis

    Directory of Open Access Journals (Sweden)

    X. Zhou

    Full Text Available This meta-analysis compared the efficacy and safety of the contact force (CF-sensing catheter and second-generation cryoballoon (CB ablation for treating atrial fibrillation (AF. Six controlled clinical trials comparing ablation for AF using a CF-sensing catheter or second-generation CB were identified from PubMed, EMBASE, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure. The procedure duration was significantly lower in the CB group compared with that in the CF group [mean difference (MD=29.4; 95%CI=17.84–40.96; P=0.01], whereas there was no difference between the groups for fluoroscopy duration (MD=0.59; 95%CI=–4.48–5.66; P=0.82. Moreover, there was no difference in the incidence of non-lethal complications (embolic event, tamponade, femoral/subclavian hematoma, arteriovenous fistula, pulmonary vein stenosis, phrenic nerve palsy, and esophageal injury between the CB and the CF groups (8.38 vs 5.35%; RR=0.66; 95%CI=0.37–1.17; P=0.15. Transient phrenic nerve palsy occurred in 17 of 326 patients (5.2% of the CB group vs none in the CF group (RR=0.12; 95%CI=0.03–0.43; P=0.001. A comparable proportion of patients in CF and CB groups suffered from AF recurrence during the 12-month follow-up after a single ablation procedure [risk ratio (RR=1.03; 95%CI=0.78–1.35; P=0.84]. AF ablation using CF-sensing catheters and second-generation CB showed comparable fluoroscopy duration and efficacy (during a 12-month follow-up, with shorter procedure duration and different complications in the CB group.

  13. Integrated magnetic and elastic force systems.

    Science.gov (United States)

    Bourauel, Christoph; Köklü, Saduman O; Vardimon, Alexander D

    2002-08-01

    Magnetic force increases as the distance (d) of the force- generating elements (F approximately 1/d(2)) decreases, whereas elastic force decreases as the distance decreases (F approximately kd). These opposing characteristics suggest that combining both force systems will establish an integrated system with a long-range working ability. The objective of this study was to determine the vertical closure force (F(X)) and the transverse axis moment (M(Y)) of an integrated force system, ie, attracting magnets with elastics (vertical or Classes II and III). F(X) and M(Y) were examined on the orthodontic measurement and simulation system. It was found that the integrated force system had a positive closure force (+F(X)) that never declined to 0 and a long working range. Three regions characterized the force-deflection curve of F(X): the magnetic region (0-3 mm, for magnets with 3/16-in medium elastics), in which the decline in magnetic force was larger than the increase in elastic force (6.3-2.5 N); the constant region (3-7 mm), in which the decline in magnetic force equaled the increase in elastic force (2.5-2.9 N); and the elastic region (7-10 mm), in which there was only an increase in elastic force (2.9-3.5 N). The transverse axis moment (+M(Y)), which tends to close the bite, developed especially in magnets with a single vertical elastic. Clinically, inactivation of vertical elastics by closing the mouth can be overruled by the integrated force system because it exerts adequate force level at both short and long distances.

  14. Examination of the collision force method for analyzing the responses of simple containment/deflection structures to impact by one engine rotor blade fragment

    Science.gov (United States)

    Zirin, R. M.; Witmer, E. A.

    1972-01-01

    An approximate collision analysis, termed the collision-force method, was developed for studying impact-interaction of an engine rotor blade fragment with an initially circular containment ring. This collision analysis utilizes basic mass, material property, geometry, and pre-impact velocity information for the fragment, together with any one of three postulated patterns of blade deformation behavior: (1) the elastic straight blade model, (2) the elastic-plastic straight shortening blade model, and (3) the elastic-plastic curling blade model. The collision-induced forces are used to predict the resulting motions of both the blade fragment and the containment ring. Containment ring transient responses are predicted by a finite element computer code which accommodates the large deformation, elastic-plastic planar deformation behavior of simple structures such as beams and/or rings. The effects of varying the values of certain parameters in each blade-behavior model were studied. Comparisons of predictions with experimental data indicate that of the three postulated blade-behavior models, the elastic-plastic curling blade model appears to be the most plausible and satisfactory for predicting the impact-induced motions of a ductile engine rotor blade and a containment ring against which the blade impacts.

  15. An experimental investigation into the deployment of 3-D, finned wing and shape memory alloy vortex generators in a forced air convection heat pipe fin stack

    International Nuclear Information System (INIS)

    Aris, M.S.; McGlen, R.; Owen, I.; Sutcliffe, C.J.

    2011-01-01

    Forced air convection heat pipe cooling systems play an essential role in the thermal management of electronic and power electronic devices such as microprocessors and IGBT's (Integrated Gate Bipolar Transistors). With increasing heat dissipation from these devices, novel methods of improving the thermal performance of fin stacks attached to the heat pipe condenser section are required. The current work investigates the use of a wing type surface protrusions in the form of 3-D delta wing tabs adhered to the fin surface, thin wings punched-out of the fin material and TiNi shape memory alloy delta wings which changed their angles of attack based on the fin surface temperature. The longitudinal vortices generated from the wing designs induce secondary mixing of the cooler free stream air entering the fin stack with the warmer fluid close to the fin surfaces. The change in angle of the attack of the active delta wings provide heat transfer enhancement while managing flow pressure losses across the fin stack. A heat transfer enhancement of 37% compared to a plain fin stack was obtained from the 3-D tabs in a staggered arrangement. The punched-out delta wings in the staggered and inline arrangements provided enhancements of 30% and 26% respectively. Enhancements from the active delta wings were lower at 16%. However, as these devices reduce the pressure drop through the fin stack by approximately 19% in the de-activate position, over the activated position, a reduction in fan operating cost may be achieved for systems operating with inlet air temperatures below the maximum inlet temperature specification for the device. CFD analysis was also carried out to provide additional detail of the local heat transfer enhancement effects. The CFD results corresponded well with previously published reports and were consistent with the experimental findings. - Highlights: → Heat transfer enhancements of heat pipe fin stacks was successfully achieved using fixed and active delta

  16. Force Dynamics During T Cell Activation

    Science.gov (United States)

    Garcia, David A.; Upadhyaya, Arpita

    T cell activation is an essential step in the adaptive immune response. The binding of the T cell receptor (TCR) with antigen triggers signaling cascades and cell spreading. Physical forces exerted on the TCR by the cytoskeleton have been shown to induce signaling events. While cellular forces are known to depend on the mechanical properties of the cytoskeleton, the biophysical mechanisms underlying force induced activation of TCR-antigen interactions unknown. Here, we use traction force microscopy to measure the force dynamics of activated Jurkat T cells. The movements of beads embedded in an elastic gel serve as a non-invasive reporter of cytoskeletal and molecular motor dynamics. We examined the statistical structure of the force profiles throughout the cell during signaling activation. We found two spatially distinct active regimes of force generation characterized by different time scales. Typically, the interior of the cells was found to be more active than the periphery. Inhibition of myosin motor activity altered the correlation time of the bead displacements indicating additional sources of stochastic force generation. Our results indicate a complex interaction between myosin activity and actin polymerization dynamics in producing cellular forces in immune cells.

  17. Phase transition behaviors of the supported DPPC bilayer investigated by sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM).

    Science.gov (United States)

    Wu, Heng-Liang; Tong, Yujin; Peng, Qiling; Li, Na; Ye, Shen

    2016-01-21

    The phase transition behaviors of a supported bilayer of dipalmitoylphosphatidyl-choline (DPPC) have been systematically evaluated by in situ sum frequency generation (SFG) vibrational spectroscopy and atomic force microscopy (AFM). By using an asymmetric bilayer composed of per-deuterated and per-protonated monolayers, i.e., DPPC-d75/DPPC and a symmetric bilayer of DPPC/DPPC, we were able to probe the molecular structural changes during the phase transition process of the lipid bilayer by SFG spectroscopy. It was found that the DPPC bilayer is sequentially melted from the top (adjacent to the solution) to bottom leaflet (adjacent to the substrate) over a wide temperature range. The conformational ordering of the supported bilayer does not decrease (even slightly increases) during the phase transition process. The conformational defects in the bilayer can be removed after the complete melting process. The phase transition enthalpy for the bottom leaflet was found to be approximately three times greater than that for the top leaflet, indicating a strong interaction of the lipids with the substrate. The present SFG and AFM observations revealed similar temperature dependent profiles. Based on these results, the temperature-induced structural changes in the supported lipid bilayer during its phase transition process are discussed in comparison with previous studies.

  18. Examining the financial performance of micro-generation wind projects and the subsidy effect of feed-in tariffs for urban locations in the United Kingdom

    International Nuclear Information System (INIS)

    Walters, Ryan; Walsh, Philip R.

    2011-01-01

    This paper seeks to evaluate the effect of the upcoming 2010 UK Feed-in Tariff (UK FIT) on decentralised small wind-energy installations at the household and building level in urban locations. It is projected that the UK FIT will stimulate an unprecedented surge in building-mounted turbine installation. The tariff amount must stimulate incentive but mitigate the likelihood of distortions in the competitive electricity market. To analyse these issues, measured energy output from sites in the Warwick Wind Trials Project (WWTP) is converted into revenue in a net-present-value (NPV) framework for assessing commercial purchases of small wind systems. Variances in project variables are examined through NPV simulations using Monte Carlo analysis to capture permutations of small wind-project performance in the UK-with and without the UK FIT. Our research concludes that the proposed tariff amount of 30.5 p/kWh will not significantly boost the economic attractiveness of mildly selective (WWTP-based) sites in the UK. Furthermore, the fixed-tariff rate ( Pounds /kWh generated) could cause inefficiencies applied across uneven wind-resource distribution. The results of this study suggest further examination of policy related to micro-generation, in particular decentralised small wind projects. - Highlights: → Feed-in tariff (FIT) policy for urban UK small wind projects. → Determination of economic attractiveness (NPV) of projects. → Application of performance data from Warwick Wind Trials. → Need for higher tariff rate to provide average project with NPV>0. → Recommend reconsideration of FIT policy for urban small wind projects.

  19. A policy study examining the use of imported LNG for gas-fired power generation on the southeast coast of China

    International Nuclear Information System (INIS)

    Li Yajun; Bai Fangfang

    2010-01-01

    Since China's energy demand is growing quickly, speeding up the development of natural gas is an important substitute and supplement for coal and oil. The development of the natural gas market in many developing countries has demonstrated that the success of the whole project hinges upon the success of gas-fired power generation. However, under the current energy pricing system in China, the advantages of gas-fired power plants, such as low investment costs and high efficiency, have not been able to offset the low price of coal. The gas-fired power plants, both at downstream of the Liquefied Natural Gas (LNG) industry and upstream of the power sector, are faced with a dilemma. In order to solve the problems facing gas-fired power projects while providing policy guidance for the future development of gas-fired power projects, the policy of gas-fired power generation using imported LNG on the southeastern coast of China was examined. This study aims to identify the position of the national energy strategy that China should import some LNG from the other countries, to guide the development of energy policy in this region, and to formulate some clear policy measures.

  20. Force transmission in epithelial tissues.

    Science.gov (United States)

    Vasquez, Claudia G; Martin, Adam C

    2016-03-01

    In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells' decisions to divide, die, or differentiate. Forces are transmitted across epithelia because cells are mechanically linked through junctional complexes, and forces can propagate through the cell cytoplasm. Here, we review some of the molecular mechanisms responsible for force generation, with a specific focus on the actomyosin cortex and adherens junctions. We then discuss evidence for how these mechanisms promote cell shape changes and force transmission in tissues. © 2016 Wiley Periodicals, Inc.

  1. Women Faculty, Professional Identity, and Generational Disposition

    Science.gov (United States)

    Marine, Susan B.; Martínez Alemán, Ana M.

    2018-01-01

    In an exploratory qualitative study, the generational dispositions of tenured women faculty from the Boomer Generation were examined. As pioneers and now senior members in the academic profession in the Golden Era of American higher education, they exist in a common historical location characterized by cultural forces and events that helped to…

  2. Passive Joint Forces Are Tuned to Limb Use in Insects and Drive Movements without Motor Activity

    Science.gov (United States)

    Ache, Jan M.; Matheson, Thomas

    2013-01-01

    Summary Background Limb movements are generally driven by active muscular contractions working with and against passive forces arising in muscles and other structures. In relatively heavy limbs, the effects of gravity and inertia predominate, whereas in lighter limbs, passive forces intrinsic to the limb are of greater consequence. The roles of passive forces generated by muscles and tendons are well understood, but there has been little recognition that forces originating within joints themselves may also be important, and less still that these joint forces may be adapted through evolution to complement active muscle forces acting at the same joint. Results We examined the roles of passive joint forces in insect legs with different arrangements of antagonist muscles. We first show that passive forces modify actively generated movements of a joint across its working range, and that they can be sufficiently strong to generate completely passive movements that are faster than active movements observed in natural behaviors. We further demonstrate that some of these forces originate within the joint itself. In legs of different species adapted to different uses (walking, jumping), these passive joint forces complement the balance of strength of the antagonist muscles acting on the joint. We show that passive joint forces are stronger where they assist the weaker of two antagonist muscles. Conclusions In limbs where the dictates of a key behavior produce asymmetry in muscle forces, passive joint forces can be coadapted to provide the balance needed for the effective generation of other behaviors. PMID:23871240

  3. Using the kaleidoscope career model to examine generational differences in work attitudes between Gen X and Gen Y– within Malaysia Perspective

    OpenAIRE

    Koay, Chee Hua Alwyn

    2016-01-01

    Generation Y (also known as Yers) has started to take a prominent position in today’s workforce. With this new position comes a new territory of research. The research about this generation has increased over the past years, with most of this research focusing on characteristics of GenY (Sheahan (2005), Martin (2005), Armour (2005)) and the differences between generations (Smola and Sutton (2002), Cennamo and Gardner (2008)). Noticeably, there has been many literature and news (Hoi J., 2013) ...

  4. In Situ Adsorption Studies at the Solid/Liquid Interface: Characterization of Biological Surfaces and Interfaces Using Sum Frequency Generation Vibrational Spectroscopy, Atomic Force Microscopy, and Quartz Crystal Microbalance

    International Nuclear Information System (INIS)

    Phillips, D.C.

    2006-01-01

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and quartz crystal microbalance (QCM) have been used to study the molecular surface structure, surface topography and mechanical properties, and quantitative adsorbed amount of biological molecules at the solid-liquid interface. The molecular-level behavior of designed peptides adsorbed on hydrophobic polystyrene and hydrophilic silica substrates has been examined as a model of protein adsorption on polymeric biomaterial surfaces. Proteins are such large and complex molecules that it is difficult to identify the features in their structure that lead to adsorption and interaction with solid surfaces. Designed peptides which possess secondary structure provide simple model systems for understanding protein adsorption. Depending on the amino acid sequence of a peptide, different secondary structures (α-helix and β-sheet) can be induced at apolar (air/liquid or air/solid) interfaces. Having a well-defined secondary structure allows experiments to be carried out under controlled conditions, where it is possible to investigate the affects of peptide amino acid sequence and chain length, concentration, buffering effects, etc. on adsorbed peptide structure. The experiments presented in this dissertation demonstrate that SFG vibrational spectroscopy can be used to directly probe the interaction of adsorbing biomolecules with a surface or interface. The use of well designed model systems aided in isolation of the SFG signal of the adsorbing species, and showed that surface functional groups of the substrate are sensitive to surface adsorbates. The complementary techniques of AFM and QCM allowed for deconvolution of the effects of surface topography and coverage from the observed SFG spectra. Initial studies of biologically relevant surfaces are also presented: SFG spectroscopy was used to study the surface composition of common soil bacteria for use in bioremediation of nuclear waste

  5. In Situ Adsorption Studies at the Solid/Liquid Interface:Characterization of Biological Surfaces and Interfaces Using SumFrequency Generation Vibrational Spectroscopy, Atomic Force Microscopy,and Quartz Crystal Microbalance

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Diana Christine [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and quartz crystal microbalance (QCM) have been used to study the molecular surface structure, surface topography and mechanical properties, and quantitative adsorbed amount of biological molecules at the solid-liquid interface. The molecular-level behavior of designed peptides adsorbed on hydrophobic polystyrene and hydrophilic silica substrates has been examined as a model of protein adsorption on polymeric biomaterial surfaces. Proteins are such large and complex molecules that it is difficult to identify the features in their structure that lead to adsorption and interaction with solid surfaces. Designed peptides which possess secondary structure provide simple model systems for understanding protein adsorption. Depending on the amino acid sequence of a peptide, different secondary structures (α-helix and β-sheet) can be induced at apolar (air/liquid or air/solid) interfaces. Having a well-defined secondary structure allows experiments to be carried out under controlled conditions, where it is possible to investigate the affects of peptide amino acid sequence and chain length, concentration, buffering effects, etc. on adsorbed peptide structure. The experiments presented in this dissertation demonstrate that SFG vibrational spectroscopy can be used to directly probe the interaction of adsorbing biomolecules with a surface or interface. The use of well designed model systems aided in isolation of the SFG signal of the adsorbing species, and showed that surface functional groups of the substrate are sensitive to surface adsorbates. The complementary techniques of AFM and QCM allowed for deconvolution of the effects of surface topography and coverage from the observed SFG spectra. Initial studies of biologically relevant surfaces are also presented: SFG spectroscopy was used to study the surface composition of common soil bacteria for use in bioremediation of nuclear waste.

  6. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Koffas, Telly Stelianos [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to

  7. The relationship of motor unit size, firing rate and force.

    Science.gov (United States)

    Conwit, R A; Stashuk, D; Tracy, B; McHugh, M; Brown, W F; Metter, E J

    1999-07-01

    Using a clinical electromyographic (EMG) protocol, motor units were sampled from the quadriceps femoris during isometric contractions at fixed force levels to examine how average motor unit size and firing rate relate to force generation. Mean firing rates (mFRs) and sizes (mean surface-detected motor unit action potential (mS-MUAP) area) of samples of active motor units were assessed at various force levels in 79 subjects. MS-MUAP size increased linearly with increased force generation, while mFR remained relatively constant up to 30% of a maximal force and increased appreciably only at higher force levels. A relationship was found between muscle force and mS-MUAP area (r2 = 0.67), mFR (r2 = 0.38), and the product of mS-MUAP area and mFR (mS-MUAP x mFR) (r2 = 0.70). The results support the hypothesis that motor units are recruited in an orderly manner during forceful contractions, and that in large muscles only at higher levels of contraction ( > 30% MVC) do mFRs increase appreciably. MS-MUAP and mFR can be assessed using clinical EMG techniques and they may provide a physiological basis for analyzing the role of motor units during muscle force generation.

  8. The R21C Mutation in Cardiac Troponin I Imposes Differences in Contractile Force Generation between the Left and Right Ventricles of Knock-In Mice

    Directory of Open Access Journals (Sweden)

    Jingsheng Liang

    2015-01-01

    Full Text Available We investigated the effect of the hypertrophic cardiomyopathy-linked R21C (arginine to cysteine mutation in human cardiac troponin I (cTnI on the contractile properties and myofilament protein phosphorylation in papillary muscle preparations from left (LV and right (RV ventricles of homozygous R21C+/+ knock-in mice. The maximal steady-state force was significantly reduced in skinned papillary muscle strips from the LV compared to RV, with the latter displaying the level of force observed in LV or RV from wild-type (WT mice. There were no differences in the Ca2+ sensitivity between the RV and LV of R21C+/+ mice; however, the Ca2+ sensitivity of force was higher in RV-R21C+/+ compared with RV-WT and lower in LV- R21C+/+ compared with LV-WT. We also observed partial loss of Ca2+ regulation at low [Ca2+]. In addition, R21C+/+-KI hearts showed no Ser23/24-cTnI phosphorylation compared to LV or RV of WT mice. However, phosphorylation of the myosin regulatory light chain (RLC was significantly higher in the RV versus LV of R21C+/+ mice and versus LV and RV of WT mice. The difference in RLC phosphorylation between the ventricles of R21C+/+ mice likely contributes to observed differences in contractile force and the lower tension monitored in the LV of HCM mice.

  9. The Situational Leadership Approach Effects on Employee Motivation in Multi-Generational Information Technology Organizations

    Science.gov (United States)

    Irby, Thaddaeus

    2011-01-01

    This study examines the three generations comprising today's IT organizations to determine whether the Situational Leadership approach is effective in motivating this diverse work force to perform project-related tasks. Baby Boomer employees, Generation X employees, and Generation Y employees are the three generations actively employed in IT…

  10. HeatmapGenerator: high performance RNAseq and microarray visualization software suite to examine differential gene expression levels using an R and C++ hybrid computational pipeline.

    Science.gov (United States)

    Khomtchouk, Bohdan B; Van Booven, Derek J; Wahlestedt, Claes

    2014-01-01

    The graphical visualization of gene expression data using heatmaps has become an integral component of modern-day medical research. Heatmaps are used extensively to plot quantitative differences in gene expression levels, such as those measured with RNAseq and microarray experiments, to provide qualitative large-scale views of the transcriptonomic landscape. Creating high-quality heatmaps is a computationally intensive task, often requiring considerable programming experience, particularly for customizing features to a specific dataset at hand. Software to create publication-quality heatmaps is developed with the R programming language, C++ programming language, and OpenGL application programming interface (API) to create industry-grade high performance graphics. We create a graphical user interface (GUI) software package called HeatmapGenerator for Windows OS and Mac OS X as an intuitive, user-friendly alternative to researchers with minimal prior coding experience to allow them to create publication-quality heatmaps using R graphics without sacrificing their desired level of customization. The simplicity of HeatmapGenerator is that it only requires the user to upload a preformatted input file and download the publicly available R software language, among a few other operating system-specific requirements. Advanced features such as color, text labels, scaling, legend construction, and even database storage can be easily customized with no prior programming knowledge. We provide an intuitive and user-friendly software package, HeatmapGenerator, to create high-quality, customizable heatmaps generated using the high-resolution color graphics capabilities of R. The software is available for Microsoft Windows and Apple Mac OS X. HeatmapGenerator is released under the GNU General Public License and publicly available at: http://sourceforge.net/projects/heatmapgenerator/. The Mac OS X direct download is available at: http://sourceforge.net/projects/heatmapgenerator/files/HeatmapGenerator

  11. The Effects of Spanwise Structures and Unsteady Forcing of Vortex Generators on a Shock-Induced Separated Flow Using Planar Laser Scattering

    National Research Council Canada - National Science Library

    Searcy, Jeffrey A

    2006-01-01

    Through the use of planar laser scattering, the effects of vortex generators (VGs) on the separation shock in an unswept compression ramp interaction have been investigated in a Mach 2 and Mach 5 wind funnel...

  12. Institutionalizing Security Force Assistance

    National Research Council Canada - National Science Library

    Binetti, Michael R

    2008-01-01

    .... It looks at the manner in which security assistance guidance is developed and executed. An examination of national level policy and the guidance from senior military and civilian leaders highlights the important role of Security Force Assistance...

  13. Special Research Column: Empathetic Genres, Empathetic Spaces, and Mentoring: Examining Contemporary Research on First-Generation College Students in First-Year Writing

    Science.gov (United States)

    Borchert, Jessica Jorgenson

    2017-01-01

    This article focuses on contemporary research on first-generation college students bringing to light pedagogical interventions that can be used in the classroom to help engage and retain these students. The pedagogical interventions focus on reflective and personal writing in the classroom, creating safe spaces, and opening up opportunities for…

  14. An Introductory Mixed-Methods Intersectionality Analysis of College Access and Equity: An Examination of First-Generation Asian Americans and Pacific Islanders

    Science.gov (United States)

    Museus, Samuel D.

    2011-01-01

    In this article, the author discusses how researchers can use mixed-methods approaches and intersectional analyses to understand college access among first-generation Asian American and Pacific Islanders (AAPIs). First, he discusses the utility of mixed-methods approaches and intersectionality research in studying college access. Then, he…

  15. An Examination of the Impact of Major Changing Patterns on the Academic Performance and Career Decision-Making Self-Efficacy of First Generation College Students

    Science.gov (United States)

    McLean, Carrie Frederick

    2016-01-01

    Career development studies show that First Generation College Students (FCGS) have unique career development needs, less college knowledge, and the increased likelihood that they will not complete college. There is evidence in the research that changing majors could impact a student's ability to complete college successfully, especially if they…

  16. The critical examination of X-ray generating equipment in diagnostic radiology. Guidance on the interpretation of the Ionising Radiation Regulations 1985, Regulation 32(2)a

    International Nuclear Information System (INIS)

    1998-01-01

    Regulation 32(2)a requires an examination, where appropriate, of X-ray equipment and its operating environment, following its installation, repair or modification. In this context 'appropriate' means - 'if there are possible radiation protection implications'. The examination should be carried out before the equipment is brought into use. The intent of the Regulation is to ensure that the installation process does not compromise the radiation safety of the equipment as provided for by its original design and manufacture, and that any persons who might be exposed are adequately protected. However, the scope of the Regulation does not directly cover features controlling the optimisation of dose for a medical exposure. An examination of the equipment relating to the radiation protection consequences of the way it was installed is required. This is termed 'critical', emphasising the need to review the installation to a greater degree than the simple fulfilment of a preconceived test procedure. The involvement of a radiation protection adviser is required as an expert in radiation safety. This document provides guidance on when it is necessary to carry out a critical examination, and on its content. The Ionising Radiations Regulations 1985 firmly place the responsibility for ensuring that a critical examination is carried out, on the installer of the equipment. However, knowledge of various aspects of the critical examination is also relevant to employers who manage health related facilities, as well as their RPAs, and physicists who carry out equipment tests. Aside from the actual examination itself, there are issues pertaining to purchase contracts, and a knowledge of the satisfactory completion of a critical examination will be relevant to an employer in fulfilling his duties under Regulations 6 and 33. (author)

  17. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2012

    2012-01-01

    The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

  18. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  19. An Empirical Examination of the Permanence of Performance and Response Patterns Generated by a CRM-Reading Produced by Expert Judgment.

    Science.gov (United States)

    Hess, Richard Wayne

    Stability of performance on a criterion referenced reading test was examined for 413 students in grades one through six. The test, which measures 367 behavioral reading objectives, was administered twice to each student, with an interval of at least three weeks between the first and second administrations. Three statistical indices of permanence…

  20. Experimental and numerical examination of eddy (Foucault) currents in rotating micro-coils: Generation of heat and its impact on sample temperature.

    Science.gov (United States)

    Aguiar, Pedro M; Jacquinot, Jacques-François; Sakellariou, Dimitris

    2009-09-01

    The application of nuclear magnetic resonance (NMR) to systems of limited quantity has stimulated the use of micro-coils (diameter Foucault (eddy) currents, which generate heat. We report the first data acquired with a 4mm MACS system and spinning up to 10kHz. The need to spin faster necessitates improved methods to control heating. We propose an approximate solution to calculate the power losses (heat) from the eddy currents for a solenoidal coil, in order to provide insight into the functional dependencies of Foucault currents. Experimental tests of the dependencies reveal conditions which result in reduced sample heating and negligible temperature distributions over the sample volume.

  1. Experimental and numerical examination of eddy (Foucault) currents in rotating micro-coils: Generation of heat and its impact on sample temperature

    Science.gov (United States)

    Aguiar, Pedro M.; Jacquinot, Jacques-François; Sakellariou, Dimitris

    2009-09-01

    The application of nuclear magnetic resonance (NMR) to systems of limited quantity has stimulated the use of micro-coils (diameter Foucault (eddy) currents, which generate heat. We report the first data acquired with a 4 mm MACS system and spinning up to 10 kHz. The need to spin faster necessitates improved methods to control heating. We propose an approximate solution to calculate the power losses (heat) from the eddy currents for a solenoidal coil, in order to provide insight into the functional dependencies of Foucault currents. Experimental tests of the dependencies reveal conditions which result in reduced sample heating and negligible temperature distributions over the sample volume.

  2. Widespread tsunami-like waves of 23-27 June in the Mediterranean and Black Seas generated by high-altitude atmospheric forcing

    Science.gov (United States)

    Šepić, Jadranka; Vilibić, Ivica; Rabinovich, Alexander B.; Monserrat, Sebastian

    2015-01-01

    A series of tsunami-like waves of non-seismic origin struck several southern European countries during the period of 23 to 27 June 2014. The event caused considerable damage from Spain to Ukraine. Here, we show that these waves were long-period ocean oscillations known as meteorological tsunamis which are generated by intense small-scale air pressure disturbances. An unique atmospheric synoptic pattern was tracked propagating eastward over the Mediterranean and the Black seas in synchrony with onset times of observed tsunami waves. This pattern favoured generation and propagation of atmospheric gravity waves that induced pronounced tsunami-like waves through the Proudman resonance mechanism. This is the first documented case of a chain of destructive meteorological tsunamis occurring over a distance of thousands of kilometres. Our findings further demonstrate that these events represent potentially dangerous regional phenomena and should be included in tsunami warning systems. PMID:26119833

  3. Widespread tsunami-like waves of 23-27 June in the Mediterranean and Black Seas generated by high-altitude atmospheric forcing.

    Science.gov (United States)

    Šepić, Jadranka; Vilibić, Ivica; Rabinovich, Alexander B; Monserrat, Sebastian

    2015-06-29

    A series of tsunami-like waves of non-seismic origin struck several southern European countries during the period of 23 to 27 June 2014. The event caused considerable damage from Spain to Ukraine. Here, we show that these waves were long-period ocean oscillations known as meteorological tsunamis which are generated by intense small-scale air pressure disturbances. An unique atmospheric synoptic pattern was tracked propagating eastward over the Mediterranean and the Black seas in synchrony with onset times of observed tsunami waves. This pattern favoured generation and propagation of atmospheric gravity waves that induced pronounced tsunami-like waves through the Proudman resonance mechanism. This is the first documented case of a chain of destructive meteorological tsunamis occurring over a distance of thousands of kilometres. Our findings further demonstrate that these events represent potentially dangerous regional phenomena and should be included in tsunami warning systems.

  4. Interaction between force production and cognitive performance in humans

    NARCIS (Netherlands)

    Zijdewind, Inge; van Duinen, Hiske; Zielman, R; Lorist, MM

    Objective: A dual task paradigm was used to examine the effects of the generation of force on cognitive performance. Methods: Subjects (n = 22) were asked to respond to auditory stimuli with their left middle or index finger and concurrently maintain a sub-maximal contraction with their right index

  5. Forced marriage.

    Science.gov (United States)

    2007-06-01

    Guidelines to help A&E staff and other healthcare professionals who suspect cases of forced marriage were launched this month by the government. The guidelines provide practical advice on how to recognise the warning signs, and what to do if patients disclose that they have been, or are about to be, forced to marry. The guidelines, Dealing with Cases of Forced Marriage, are available at www.fco.gov.uk/forcedmarriage.

  6. Force Reproduction Error Depends on Force Level, whereas the Position Reproduction Error Does Not

    NARCIS (Netherlands)

    Onneweer, B.; Mugge, W.; Schouten, Alfred Christiaan

    2016-01-01

    When reproducing a previously perceived force or position humans make systematic errors. This study determined the effect of force level on force and position reproduction, when both target and reproduction force are self-generated with the same hand. Subjects performed force reproduction tasks at

  7. Does weightlifting increase residual force enhancement?

    Science.gov (United States)

    Siebert, Tobias; Kurch, David; Blickhan, Reinhard; Stutzig, Norman

    2016-07-05

    The force maintained following stretching of an active muscle exceeds the isometric force at the same muscle length. This residual force enhancement (RFE) is different for various muscles. It is currently unknown whether training induces changes in RFE. Weightlifters perform a large number of eccentric contractions during training, and RFE might be functionally relevant. The aim of this study was to examine whether there is increased RFE in weightlifters versus a reference group. Therefore, we measured external reaction forces during a multi-joint leg extension in weightlifters (n=10) and a reference group (n=11) using a motor driven leg press dynamometer (ISOMED 2000). Steady state isometric forces after stretching were compared to the corresponding forces obtained during isometric reference contractions. Statistical analyses yielded a significant RFE for both groups (pweightlifting group versus the reference group. We conclude that long-term weightlifting has only a minor influence on RFE. We speculate that the specific training including a combination of eccentric and concentric exercises induced almost no changes in titin-isoform expression which may be responsible for generation of RFE after active muscle stretching. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The VicGeneration study - a birth cohort to examine the environmental, behavioural and biological predictors of early childhood caries: background, aims and methods

    Science.gov (United States)

    2010-01-01

    Background Dental caries (decay) during childhood is largely preventable however it remains a significant and costly public health concern, identified as the most prevalent chronic disease of childhood. Caries in children aged less than five years (early childhood caries) is a rapid and progressive disease that can be painful and debilitating, and significantly increases the likelihood of poor child growth, development and social outcomes. Early childhood caries may also result in a substantial social burden on families and significant costs to the public health system. A disproportionate burden of disease is also experienced by disadvantaged populations. Methods/Design This study involves the establishment of a birth cohort in disadvantaged communities in Victoria, Australia. Children will be followed for at least 18 months and the data gathered will explore longitudinal relationships and generate new evidence on the natural history of early childhood caries, the prevalence of the disease and relative contributions of risk and protective biological, environmental and behavioural factors. Specifically, the study aims to: 1. Describe the natural history of early childhood caries (at ages 1, 6, 12 and 18 months), tracking pathways from early bacterial colonisation, through non-cavitated enamel white spot lesions to cavitated lesions extending into dentine. 2. Enumerate oral bacterial species in the saliva of infants and their primary care giver. 3. Identify the strength of concurrent associations between early childhood caries and putative risk and protective factors, including biological (eg microbiota, saliva), environmental (fluoride exposure) and socio-behavioural factors (proximal factors such as: feeding practices and oral hygiene; and distal factors such as parental health behaviours, physical health, coping and broader socio-economic conditions). 4. Quantify the longitudinal relationships between these factors and the development and progression of early

  9. The VicGeneration study - a birth cohort to examine the environmental, behavioural and biological predictors of early childhood caries: background, aims and methods

    Directory of Open Access Journals (Sweden)

    Dashper Stuart

    2010-02-01

    Full Text Available Abstract Background Dental caries (decay during childhood is largely preventable however it remains a significant and costly public health concern, identified as the most prevalent chronic disease of childhood. Caries in children aged less than five years (early childhood caries is a rapid and progressive disease that can be painful and debilitating, and significantly increases the likelihood of poor child growth, development and social outcomes. Early childhood caries may also result in a substantial social burden on families and significant costs to the public health system. A disproportionate burden of disease is also experienced by disadvantaged populations. Methods/Design This study involves the establishment of a birth cohort in disadvantaged communities in Victoria, Australia. Children will be followed for at least 18 months and the data gathered will explore longitudinal relationships and generate new evidence on the natural history of early childhood caries, the prevalence of the disease and relative contributions of risk and protective biological, environmental and behavioural factors. Specifically, the study aims to: 1. Describe the natural history of early childhood caries (at ages 1, 6, 12 and 18 months, tracking pathways from early bacterial colonisation, through non-cavitated enamel white spot lesions to cavitated lesions extending into dentine. 2. Enumerate oral bacterial species in the saliva of infants and their primary care giver. 3. Identify the strength of concurrent associations between early childhood caries and putative risk and protective factors, including biological (eg microbiota, saliva, environmental (fluoride exposure and socio-behavioural factors (proximal factors such as: feeding practices and oral hygiene; and distal factors such as parental health behaviours, physical health, coping and broader socio-economic conditions. 4. Quantify the longitudinal relationships between these factors and the development and

  10. GENERATION OF A VECTOR OF NODAL FORCES PRODUCED BY LOADS PRE-SET BY THE ARBITRARY SCULPTED SURFACE DESIGNATED FOR UNIVERSAL STRESS ANALYSIS SOFTWARE

    Directory of Open Access Journals (Sweden)

    Shaposhnikov Nikolay Nikolaevich

    2012-10-01

    A user may select the surface accommodating any simulated arbitrary load; further, a point of the pre-set load intensity specified in the Distributed Load Q field of interface window Distributed Loads, and the point of zero intensity load are to be specified. The above source data are used to calculate the scale coefficient of transition from linear distances to the real value of the load intensity generated within the coordinate surface. The point of zero load intensity represents a virtual plane of zero distributed load values. The proposed software designated for the conversion of arbitrary distributed loads into the nodal load is compact; therefore, it may be integrated into modules capable of exporting the nodal load into other systems of strength analysis, though functioning as a problem-oriented geometrical utility of AutoCAD.

  11. Different forces

    CERN Multimedia

    1982-01-01

    The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies or phenomena in which they have a dominant role.

  12. Study of heat generation and cutting force according to minimization of grain size (500 nm to 180 nm) of WC ball endmill using FEM

    Science.gov (United States)

    Byeon, J. H.; Ahmed, F.; Ko, T. J.; lee, D. K.; Kim, J. S.

    2018-03-01

    As the industry develops, miniaturization and refinement of products are important issues. Precise machining is required for cutting, which is a typical method of machining a product. The factor determining the workability of the cutting process is the material of the tool. Tool materials include carbon tool steel, alloy tool steel, high-speed steel, cemented carbide, and ceramics. In the case of a carbide material, the smaller the particle size, the better the mechanical properties with higher hardness, strength and toughness. The specific heat, density, and thermal diffusivity are also changed through finer particle size of the material. In this study, finite element analysis was performed to investigate the change of heat generation and cutting power depending on the physical properties (specific heat, density, thermal diffusivity) of tool material. The thermal conductivity coefficient was obtained by measuring the thermal diffusivity, specific heat, and density of the material (180 nm) in which the particle size was finer and the particle material (0.05 μm) in the conventional size. The coefficient of thermal conductivity was calculated as 61.33 for 180nm class material and 46.13 for 0.05μm class material. As a result of finite element analysis using this value, the average temperature of exothermic heat of micronized particle material (180nm) was 532.75 °C and the temperature of existing material (0.05μm) was 572.75 °C. Cutting power was also compared but not significant. Therefore, if the thermal conductivity is increased through particle refinement, the surface power can be improved and the tool life can be prolonged by lowering the temperature generated in the tool during machining without giving a great influence to the cutting power.

  13. Loudness control in pianists as exemplified in keystroke force measurements on different touches.

    Science.gov (United States)

    Kinoshita, Hiroshi; Furuya, Shinichi; Aoki, Tomoko; Altenmüller, Eckart

    2007-05-01

    The relationship between the key depression force on an upright piano and the level of loudness of a generated tone was examined when pianists hit a force-sensor built-in key with "struck" or "pressed" type of touch. The vertical displacement of the key, and the radiated piano sounds were also recorded. It was found that for both types of touch, simple exponential functions could adequately describe the relation of the force amplitude with the level of the piano tone as well as that of the impulse of the force with the piano tone. The impulse of the force generated before the maximum key depression moment commonly amounted to above 80% of the total impulse produced at the tone below mezzo-forte. It, however, decreased to around 60% at fortissimo, indicating a decrease in the efficiency of the force application for sound production. The two types of touch differed in their force profiles. The struck touch was characterized by a steeper initial force increase with greater fluctuations in the subsequent period than the pressed touch. The struck touch also demonstrated lower maximum force and less impulse at fortissimo. The inter-pianist variation in the force and impulse, and the "finger-noise" are also herein examined.

  14. Method of Calibrating a Force Balance

    Science.gov (United States)

    Parker, Peter A. (Inventor); Rhew, Ray D. (Inventor); Johnson, Thomas H. (Inventor); Landman, Drew (Inventor)

    2015-01-01

    A calibration system and method utilizes acceleration of a mass to generate a force on the mass. An expected value of the force is calculated based on the magnitude and acceleration of the mass. A fixture is utilized to mount the mass to a force balance, and the force balance is calibrated to provide a reading consistent with the expected force determined for a given acceleration. The acceleration can be varied to provide different expected forces, and the force balance can be calibrated for different applied forces. The acceleration may result from linear acceleration of the mass or rotational movement of the mass.

  15. An analysis of factors causing the occurrence of off-design thermally induced force effects in the zone of weld joint no. 111-1 in a PGV-1000M steam generator and recommendations on excluding them

    Science.gov (United States)

    Bakirov, M. B.; Levchuk, V. I.; Povarov, V. P.; Gromov, A. F.

    2014-08-01

    Inadmissible operational flaws occurring in the critical zones of heat-transfer and mechanical equipment are commonly revealed in all nuclear power plant units both in Russia and abroad. The number of such flaws will only grow in the future because the majority of nuclear power plants have been in operation for a time that is either close to or even exceeds the assigned service life. In this connection, establishing cause-and-effect relations with regard to accelerated incipience and growth of flaws, working out compensating measures aimed at reducing operational damageability, and setting up monitoring of equipment integrity degradation of during operation are becoming the matters of utmost importance. There is a need to introduce new approaches to comprehensive diagnostics of the technical state of important nuclear power plant equipment, including continuous monitoring of its operational damageability and the extent of its loading in the most critical zones. Starting from 2011, such a monitoring system has successfully been used for the Novovoronezh NPP Unit 5 in the zone of weld joint no. 111-1 of steam generator no. 4. Based on the results from operation of this system in 2011-2013, unsteady thermally induced force effects (periodic thermal shocks and temperature abnormalities) were reveled, which had not been considered in the design, and which have an essential influence on the operational loading of this part. Based on an analysis of cause-and-effect relations pertinent to temperature abnormalities connected with technological operations, a set of measures aimed at reducing the thermally induced force loads exerted on pipeline sections was developed, which includes corrections to the process regulations for safe operation and to the operating manuals (involving changes in the algorithms for manipulating with the stop and control valves in the steam generator blowdown system).

  16. Non-conservative optical forces

    Science.gov (United States)

    Sukhov, Sergey; Dogariu, Aristide

    2017-11-01

    Undoubtedly, laser tweezers are the most recognized application of optically induced mechanical action. Their operation is usually described in terms of conservative forces originating from intensity gradients. However, the fundamental optical action on matter is non-conservative. We will review different manifestations of non-conservative optical forces (NCF) and discuss their dependence on the specific spatial properties of optical fields that generate them. New developments relevant to the NCF such as tractor beams and transversal forces are also discussed.

  17. Cognitive Behaviors for Computer Generated Forces

    National Research Council Canada - National Science Library

    Gillis, Philip

    2000-01-01

    ...; hence this is a needed research and development area. The lack of existing research impacts the accurate behavior of CGF CEs, and it also affects the human resources required for CGF scenario development and exercise control in ADS...

  18. Next Generation Simulation Training for Pararescue Forces

    Science.gov (United States)

    2014-02-13

    design, and analysis as well as the build out of its information technology systems and training infrastructure at its Design and Development Center...sessions conducted immediately after training. • Written feedback – Obtained through a web-based survey tool (SurveyMonkey) Data Analysis : Analysis of the...brevity, being detailed in a classical Strengths, Weatknesses, Opportunities, Threats ( SWOT ) structure. STRENGTHS: Identified strengths of the simulation

  19. Teleoperation with virtual force feedback

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.J.

    1993-08-01

    In this paper we describe an algorithm for generating virtual forces in a bilateral teleoperator system. The virtual forces are generated from a world model and are used to provide real-time obstacle avoidance and guidance capabilities. The algorithm requires that the slaves tool and every object in the environment be decomposed into convex polyhedral Primitives. Intrusion distance and extraction vectors are then derived at every time step by applying Gilbert`s polyhedra distance algorithm, which has been adapted for the task. This information is then used to determine the compression and location of nonlinear virtual spring-dampers whose total force is summed and applied to the manipulator/teleoperator system. Experimental results validate the whole approach, showing that it is possible to compute the algorithm and generate realistic, useful psuedo forces for a bilateral teleoperator system using standard VME bus hardware.

  20. Role of uterine forces in intrauterine device embedment, perforation, and expulsion.

    Science.gov (United States)

    Goldstuck, Norman D; Wildemeersch, Dirk

    2014-01-01

    The purpose of this study was to examine factors that could help reduce primary perforation during insertion of a framed intrauterine device (IUD) and to determine factors that contribute in generating enough uterine muscle force to cause embedment and secondary perforation of an IUD. The objective was also to evaluate the main underlying mechanism of IUD expulsion. We compared known IUD insertion forces for "framed" devices with known perforation forces in vitro (hysterectomy specimens) and known IUD removal forces and calculated a range of possible intrauterine forces using pressure and surface area. These were compared with known perforation forces. IUD insertion forces range from 1.5 N to 6.5 N. Removal forces range from 1 N to 5.8 N and fracture forces from 8.7 N to 30 N depending upon device. Measured perforation forces are from 20 N to 54 N, and calculations show the uterus is capable of generating up to 50 N of myometrial force depending on internal pressure and surface area. Primary perforation with conventional framed IUDs may occur if the insertion pressure exceeds the perforation resistance of the uterine fundus. This is more likely to occur if the front end of the inserter/IUD is narrow, the passage through the cervix is difficult, and the procedure is complex. IUD embedment and secondary perforation and IUD expulsion may be due to imbalance between the size of the IUD and that of the uterine cavity, causing production of asymmetrical uterine forces. The uterine muscle seems capable of generating enough force to cause an IUD to perforate the myometrium provided it is applied asymmetrically. A physical theory for IUD expulsion and secondary IUD perforation is given.

  1. Role of uterine forces in intrauterine device embedment, perforation, and expulsion

    Science.gov (United States)

    Goldstuck, Norman D; Wildemeersch, Dirk

    2014-01-01

    Background The purpose of this study was to examine factors that could help reduce primary perforation during insertion of a framed intrauterine device (IUD) and to determine factors that contribute in generating enough uterine muscle force to cause embedment and secondary perforation of an IUD. The objective was also to evaluate the main underlying mechanism of IUD expulsion. Methods We compared known IUD insertion forces for “framed” devices with known perforation forces in vitro (hysterectomy specimens) and known IUD removal forces and calculated a range of possible intrauterine forces using pressure and surface area. These were compared with known perforation forces. Results IUD insertion forces range from 1.5 N to 6.5 N. Removal forces range from 1 N to 5.8 N and fracture forces from 8.7 N to 30 N depending upon device. Measured perforation forces are from 20 N to 54 N, and calculations show the uterus is capable of generating up to 50 N of myometrial force depending on internal pressure and surface area. Conclusion Primary perforation with conventional framed IUDs may occur if the insertion pressure exceeds the perforation resistance of the uterine fundus. This is more likely to occur if the front end of the inserter/IUD is narrow, the passage through the cervix is difficult, and the procedure is complex. IUD embedment and secondary perforation and IUD expulsion may be due to imbalance between the size of the IUD and that of the uterine cavity, causing production of asymmetrical uterine forces. The uterine muscle seems capable of generating enough force to cause an IUD to perforate the myometrium provided it is applied asymmetrically. A physical theory for IUD expulsion and secondary IUD perforation is given. PMID:25143756

  2. Evaluating amber force fields using computed NMR chemical shifts.

    Science.gov (United States)

    Koes, David R; Vries, John K

    2017-10-01

    NMR chemical shifts can be computed from molecular dynamics (MD) simulations using a template matching approach and a library of conformers containing chemical shifts generated from ab initio quantum calculations. This approach has potential utility for evaluating the force fields that underlie these simulations. Imperfections in force fields generate flawed atomic coordinates. Chemical shifts obtained from flawed coordinates have errors that can be traced back to these imperfections. We use this approach to evaluate a series of AMBER force fields that have been refined over the course of two decades (ff94, ff96, ff99SB, ff14SB, ff14ipq, and ff15ipq). For each force field a series of MD simulations are carried out for eight model proteins. The calculated chemical shifts for the 1 H, 15 N, and 13 C a atoms are compared with experimental values. Initial evaluations are based on root mean squared (RMS) errors at the protein level. These results are further refined based on secondary structure and the types of atoms involved in nonbonded interactions. The best chemical shift for identifying force field differences is the shift associated with peptide protons. Examination of the model proteins on a residue by residue basis reveals that force field performance is highly dependent on residue position. Examination of the time course of nonbonded interactions at these sites provides explanations for chemical shift differences at the atomic coordinate level. Results show that the newer ff14ipq and ff15ipq force fields developed with the implicitly polarized charge method perform better than the older force fields. © 2017 Wiley Periodicals, Inc.

  3. Nondestructive examination

    International Nuclear Information System (INIS)

    Mletzko, U.

    1980-01-01

    Visual examination is treated as a method for the control of size and shape of components, surface quality and weld performance. Dye penetrant, magnetic particle and eddy current examinations are treated as methods for the evaluation of surface defects and material properties. The limitations to certain materials, defect sizes and types are shown. (orig./RW)

  4. Cluster forcing

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    , Portugal and New Zealand have adopted the concept. Public sector interventions that aim to support cluster development in industries most often focus upon economic policy goals such as enhanced employment and improved productivity, but rarely emphasise broader societal policy goals relating to e.......g. sustainability or quality of life. The purpose of this paper is to explore how and to what extent public sector interventions that aim at forcing cluster development in industries can support sustainable development as defined in the Brundtland tradition and more recently elaborated in such concepts as eco...... in 2000 by the Welsh Automotive Task Force under the Welsh Assembly Government. The Accelerate programme takes basically different two directions: The first one, which was the first to be launched, is concerned with the upgrading of existing supply chains in the automotive industry in Wales. The programme...

  5. The Cytoskeleton and Force Response Mechanisms

    Science.gov (United States)

    Allen, Philip Goodwin

    2003-01-01

    examined the roles of several actin filament disassembly factors in the global reduction of cellular actin filaments. The calcium regulated actin filament severing protein gelsolin is not necessary for the increased actin turnover, as cells derived from gelsolin null and wildtype mice still show a reduction in total actin filament content. Instead, our work suggests that the actin binding protein cofilin may be important for these changes in actin dynamics. Cofilin binds to and enhances the disassembly of actin filaments. Using immunological methods, we observe transient changes in the phosphorylation state of cofilin upon force application that suggests that cofilin may mediate actin filament turnover. Early after force application, cofilin is transiently dephosphorylated, activating its actin disassembly activity. Subsequently, we find a hyper-phosphorylation of cofilin, rendering it inactive. This reduction in cofilin activity may explain the stability of the force induced actin structuttes. In testing this hypothesis, we aimed to generate cells that express the constituitively active kinase (LIM-kinase) that phosphorylates cofilin. lnidial attempts in the cell lines used for the our previous studies proved unsuccessful. While we prepare this work for pubication, we are continuing to study other cell lines and tissue sources to determine whether they show a reduction in F-actin content after force application.

  6. Special Forces Command and Control in Afghanistan

    National Research Council Canada - National Science Library

    Rhyne, Richard

    2004-01-01

    .... The author examines how Special Forces and conventional forces worked together in the past in Vietnam, Panama, Somalia, Haiti, Bosnia-Herzegovina, and Operations Desert Storm and Desert Shield...

  7. Army Forces for Operations Other Than War

    National Research Council Canada - National Science Library

    Sortor, Ronald

    1997-01-01

    ... contingencies influence the readiness and availability of Army forces to deploy to an MRC? We examine OOTW missions performed by the Army since 1975 and plans for possible future operations in order to define force requirements for OOTW...

  8. [The network organization of medical research in the US Armed Forces].

    Science.gov (United States)

    Golota, A S; Zubenko, A I; Ivchenko, E V; Krassiĭ, A B; Shalakhin, R A

    2014-03-01

    The current article is dedicated to the network mode of medical scientific research organization in the US Armed Forces exploring the Armed Forces Institute of Regenerative Medicine as an example. The following features of the institute are examined: the structure, definition of scientific research goals and tasks, financing, management, areas of research, the next generation of the institute. In conclusion some characteristic features of network scientific research establishment and required legal conditions are determined.

  9. A concept study of inexpensive solar power satellite using centrifugal force for self-deployment

    Science.gov (United States)

    Kuroda, Y.; Matsumoto, S.; Saito, T.; Nozaki, K.; Tadokoro, H.; Kanamori, H.; Takagi, K.

    1992-08-01

    The paper examines a concept of inexpensive solar power satellites that has the following characteristics: deployable structure, utilization of centrifual force, no EVA and no construction robots, and attitude control by natural forces such as the solar wind or the magnetic field. Taking into account these characteristics, no less than ten concepts are generated. Each idea is then evaluated according to such criteria as construction, material, and maintenance costs, and ease of attitude control.

  10. Ear examination

    Science.gov (United States)

    ... to the side, or the child's head may rest against an adult's chest. Older children and adults may sit with the head tilted toward the shoulder opposite the ear being examined. The provider will ...

  11. Effects of Gloves and Pulling Task on Achievable Downward Pull Forces on a Rung.

    Science.gov (United States)

    Beschorner, Kurt E; Slota, Gregory P; Pliner, Erika M; Spaho, Egli; Seo, Na Jin

    2018-03-01

    Objective We examined the impacts of pulling task (breakaway and pull-down tasks at different postures), glove use, and their interaction on achievable downward pull forces from a ladder rung. Background Posture, glove use, and the type of pulling task are known to affect the achievable forces. However, a gap in the literature exists regarding how these factors affect achievable downward pulling forces, which are relevant to recovery from a perturbation during ladder climbing. Methods Forty subjects completed four downward pulling tasks (breakaway force; pull force at maximum height, shoulder height, and a middle height), using three glove conditions with varying coefficient of friction (COF) levels (cotton glove, low COF; bare hand, moderate COF; and latex-coated glove, high COF) with their dominant and nondominant hand. The outcome variable was the maximum force normalized to body weight. Results The highest forces were observed for the highest hand postures (breakaway and maximum height). Increased COF led to higher forces and had a larger effect on breakaway force than the other tasks. The dominant hand was associated with higher forces than the nondominant hand. Male subjects generated greater forces than female subjects, particularly for higher hand positions. Conclusion This study suggests that a higher hand position on the ladder, while avoiding low-friction gloves, may be effective for improving recovery from ladder perturbations. Application This study may guide preferred climbing strategies (particularly those that lead to a higher hand position) for improving recovery from a perturbation during ladder climbing.

  12. Flow mechanotransduction regulates traction forces, intercellular forces, and adherens junctions

    Science.gov (United States)

    Ting, Lucas H.; Jahn, Jessica R.; Jung, Joon I.; Shuman, Benjamin R.; Feghhi, Shirin; Han, Sangyoon J.; Rodriguez, Marita L.

    2012-01-01

    Endothelial cells respond to fluid shear stress through mechanotransduction responses that affect their cytoskeleton and cell-cell contacts. Here, endothelial cells were grown as monolayers on arrays of microposts and exposed to laminar or disturbed flow to examine the relationship among traction forces, intercellular forces, and cell-cell junctions. Cells under laminar flow had traction forces that were higher than those under static conditions, whereas cells under disturbed flow had lower traction forces. The response in adhesion junction assembly matched closely with changes in traction forces since adherens junctions were larger in size for laminar flow and smaller for disturbed flow. Treating the cells with calyculin-A to increase myosin phosphorylation and traction forces caused an increase in adherens junction size, whereas Y-27362 cause a decrease in their size. Since tugging forces across cell-cell junctions can promote junctional assembly, we developed a novel approach to measure intercellular forces and found that these forces were higher for laminar flow than for static or disturbed flow. The size of adherens junctions and tight junctions matched closely with intercellular forces for these flow conditions. These results indicate that laminar flow can increase cytoskeletal tension while disturbed flow decreases cytoskeletal tension. Consequently, we found that changes in cytoskeletal tension in response to shear flow conditions can affect intercellular tension, which in turn regulates the assembly of cell-cell junctions. PMID:22447948

  13. Wind Forcing of the Pacific Ocean Using Scatterometer Wind Data

    Science.gov (United States)

    Kelly, Kathryn A.

    1999-01-01

    The long-term objective of this research was an understanding of the wind-forced ocean circulation, particularly for the Pacific Ocean. To determine the ocean's response to the winds, we first needed to generate accurate maps of wind stress. For the ocean's response to wind stress we examined the sea surface height (SSH) both from altimeters and from numerical models for the Pacific Ocean.

  14. Performance of Generating Plant: New Metrics for Industry in Transition

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    This report is the result of the work of the Performance of Generating Plant task force of the World Energy Council. The report examines the challenges of measuring and improving performance and considers some of the issues related to this field.

  15. Comparison of Frictional Forces Generated by a New Ceramic Bracket with the Conventional Brackets using Unconventional and Conventional Ligation System and the Self-ligating Brackets: An In Vitro Study.

    Science.gov (United States)

    Pasha, Azam; Vishwakarma, Swati; Narayan, Anjali; Vinay, K; Shetty, Smitha V; Roy, Partha Pratim

    2015-09-01

    Fixed orthodontic mechanotherapy is associated with friction between the bracket - wire - ligature interfaces during the sliding mechanics. A sound knowledge of the various factors affecting the magnitude of friction is of paramount importance. The present study was done to analyze and compare the frictional forces generated by a new ceramic (Clarity Advanced) bracket with the conventional, (metal and ceramic) brackets using unconventional and conventional ligation system, and the self-ligating (metal and ceramic) brackets in the dry condition. The various bracket wire ligation combinations were tested in dry condition. The brackets used were of 0.022″ × 0.028″ nominal slot dimension of MBT prescription: Stainless steel (SS) self-ligating bracket (SLB) of (SmartClip), SS Conventional bracket (CB) (Victory series), Ceramic SLB (Clarity SL), Conventional Ceramic bracket with metal slot (Clarity Bracket), Clarity Advanced Ceramic Brackets (Clarity(™) ADVANCED, 3M Unitek). These brackets were used with two types of elastomeric ligatures: Conventional Elastomeric Ligatures (CEL) (Clear medium mini modules) and Unconventional Elastomeric Ligatures (UEL) (Clear medium slide ligatures, Leone orthodontic products). The aligning and the retraction wires were used, i.e., 0.014″ nickel titanium (NiTi) wires and 0.019″ × 0.025″ SS wires, respectively. A universal strength testing machine was used to measure the friction produced between the different bracket, archwires, and ligation combination. This was done with the use of a custom-made jig being in position. Mean, standard deviation, and range were computed for the frictional values obtained. Results were subjected to statistical analysis through ANOVA. The frictional resistance observed in the new Clarity Advanced bracket with a conventional elastomeric ligature was almost similar with the Clarity metal slot bracket with a conventional elastomeric ligature. When using the UEL, the Clarity Advanced bracket

  16. The criterion for blanking-off heat-transfer tubes in the steam generators at VVER-based nuclear power plants based on the results of eddy-current examination

    Science.gov (United States)

    Lunin, V. P.; Zhdanov, A. G.; Chegodaev, V. V.; Stolyarov, A. A.

    2015-05-01

    The problem of defining the criterion for blanking off heat-transfer tubes in the steam generators at nuclear power plants on the basis of signals obtained from the standard multifrequency eddy-current examination is considered. The decision about blanking off one or another tube is presently made with reference to one parameter of the relevant signal at the working frequency, namely, with reference to its phase, which directly depends on the depth of the flaw being detected, i.e., a crack in the tube. The crack depth equal to 60% of the tube wall thickness is regarded to be the critical one, at which a decision about withdrawing such a tube out from operation (blanking off) must be taken. However, since mechanical tensile rupture tests of heat-transfer tubes show the possibility of their further use with such flaws, the secondary parameter of the signal, namely, its amplitude, must be used for determining the blanking-off criterion. The signals produced by the standard flow-type transducers in response to flaws in the form of a longitudinal crack having the depth and length within the limits permitted by the relevant regulations were calculated using 3D finite-element modeling. Based on the obtained results, the values of the eddy-current signal amplitude were determined, which, together with the signal phase value, form a new amplitude-phase criterion for blanking off heat-transfer tubes. For confirming the effectiveness of this technique, the algorithm for revealing the signal indications satisfying the proposed amplitude-phase criterion was tested on real signals obtained from operational eddy-current examination of the state of steam generator heat-transfer tubes carried out within the framework of planned preventive repair.

  17. Direct measurements of intermolecular forces by chemical force microscopy

    Science.gov (United States)

    Vezenov, Dmitri Vitalievich

    1999-12-01

    Detailed description of intermolecular forces is key to understanding a wide range of phenomena from molecular recognition to materials failure. The unique features of atomic force microscopy (AFM) to make point contact force measurements with ultra high sensitivity and to generate spatial maps of surface topography and forces have been extended to include measurements between well-defined organic molecular groups. Chemical modification of AFM probes with self-assembled monolayers (SAMs) was used to make them sensitive to specific molecular interactions. This novel chemical force microscopy (CFM) technique was used to probe forces between different molecular groups in a range of environments (vacuum, organic liquids and aqueous solutions); measure surface energetics on a nanometer scale; determine pK values of the surface acid and base groups; measure forces to stretch and unbind a short synthetic DNA duplex and map the spatial distribution of specific functional groups and their ionization state. Studies of adhesion forces demonstrated the important contribution of hydrogen bonding to interactions between simple organic functionalities. The chemical identity of the tip and substrate surfaces as well as the medium had a dramatic effect on adhesion between model monolayers. A direct correlation between surface free energy and adhesion forces was established. The adhesion between epoxy polymer and model mixed SAMs varied with the amount of hydrogen bonding component in the monolayers. A consistent interpretation of CFM measurements in polar solvents was provided by contact mechanics models and intermolecular force components theory. Forces between tips and surfaces functionalized with SAMs terminating in acid or base groups depended on their ionization state. A novel method of force titration was introduced for highly local characterization of the pK's of surface functional groups. The pH-dependent changes in friction forces were exploited to map spatially the

  18. Coriolis Force

    Science.gov (United States)

    Marciuc, Daly; Solschi, Viorel

    2017-04-01

    Understanding the Coriolis effect is essential for explaining the movement of air masses and ocean currents. The lesson we propose aims to familiarize students with the manifestation of the Coriolis effect. Students are guided to build, using the GeoGebra software, a simulation of the motion of a body, related to a rotating reference system. The mathematical expression of the Coriolis force is deduced, for particular cases, and the Foucault's pendulum is presented and explained. Students have the opportunity to deepen the subject, by developing materials related to topics such as: • Global Wind Pattern • Ocean Currents • Coriolis Effect in Long Range Shooting • Finding the latitude with a Foucault Pendulum

  19. Joining Forces

    DEFF Research Database (Denmark)

    Christiansen, Anne Mette

    2013-01-01

    The interest in Corporate Social Responsibility (CSR) has grown dramatically over the last three years in Greenland. A vast geographical area with a tiny population, Greenland has recently obtained self-government status and is going through a rapid development economically and socially...... as the country moves towards embracing extractive industries (oil, gas and mining) as a path to development. Both government, civil society and business are increasingly looking for new and innovative ways of joining forces across sectors to solve some of the country's many critical social issues. Greenlandic...... companies have over the last 23 years embraced the concept of strategic CSR and are increasingly engaging in cross-sector partnerships as part of their CSR strategy. The partnerships take different forms both in regards to number of partners, focus areas and level of strategic engagement. In the article...

  20. Virtual Computed Tomography Colonography: Evaluation of 2D and Virtual 3D Image Quality of Sub-mSv Examinations Enabled by Third-generation Dual Source Scanner Featuring Tin Filtering.

    Science.gov (United States)

    Seuss, Hannes; Janka, Rolf; Hammon, Matthias; Cavallaro, Alexander; Uder, Michael; Dankerl, Peter

    2018-01-19

    To evaluate two- and three-dimensional (2D and 3D) image quality of sub-milliSievert (mSv) computed tomography (CT) colonography utilizing a third-generation dual source CT scanner featuring a tin filter. We retrospectively evaluated 26 consecutive patients who underwent third-generation dual source CT colonography, nine with the standard-dose clinical-scan protocol (SDP) and 17 with a low-dose protocol (LDP) featuring a tin filter. Radiation dose was evaluated by volume computed tomography dose index (CTDI vol ), dose length product (DLP), effective dose (E), and size-specific dose estimate. Objective image quality was evaluated utilizing signal-to-noise ratio (SNR) derived from standardized placed regions of interest on the transverse 2D images and the ratio of SNR/CTDI vol (normalized SNR). Two radiologists in consensus assessed subjective image quality of the virtual 3D images. There were no significant differences in subjective image quality (P = .661). All examinations were rated "excellent" or "good" for diagnostic confidence. The mean total for DLP/E was 143.4 ± 29.8 mGy/3.00 ± 0.40 mSv in the SDP and therefore significantly higher than in the LDP with 36.9 ± 8.7 mGy/0.75 ± 0.16 mSv (P source CT featuring a tin filter enables consistent sub-mSv colonography without substantially impairing image quality. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  1. Joining Forces

    Science.gov (United States)

    Sawchuk, Stephen; Sparks, Sarah D.; Cavanagh, Sean; Samuels, Christina A.

    2011-01-01

    A mantra in recent years has been to blame the teachers' unions for many of the problems that beset public education. Americans only need look at Wisconsin, where the governor and lawmakers pushed through legislation curtailing the collective bargaining rights of teachers and other public employees. This special report examines the attempts by a…

  2. Effective force application in guided leg extensions

    NARCIS (Netherlands)

    Doorenbosch, C.A.M.; Veeger, H. E J; van Zandwijk, J. P.; van Ingen Schenau, G. J.

    1996-01-01

    In guided movements, limb kinematics is determined by the object on which a force is applied (as in cycling). Consequently, the force direction may deviate from the effective direction. It is examined how effective force application is related to maximal power output. A recent study, where subjects

  3. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  4. Influence of 21st century atmospheric and sea surface temperature forcing on West African climate

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Chris B [Stanford University; Ashfaq, Moetasim [ORNL; Diffenbaugh, Noah [Stanford University

    2011-01-01

    he persistence of extended drought events throughout West Africa during the 20th century has motivated a substantial effort to understand the mechanisms driving African climate variability, as well as the possible response to elevated greenhouse gas (GHG) forcing. We use an ensemble of global climate model experiments to examine the relative roles of future direct atmospheric radiative forcing and SST forcing in shaping potential future changes in boreal summer precipitation over West Africa. We find that projected increases in precipitation throughout the Western Sahel result primarily from direct atmospheric radiative forcing. The changes in atmospheric forcing generate a slight northward displacement and weakening of the African easterly jet (AEJ), a strengthening of westward monsoon flow onto West Africa and an intensification of the tropical easterly jet (TEJ). Alternatively, we find that the projected decreases in precipitation over much of the Guinea Coast region are caused by SST changes that are induced by the atmospheric radiative forcing. The changes in SSTs generate a weakening of the monsoon westerlies and the TEJ, as well as a decrease in low-level convergence and resultant rising air throughout the mid levels of the troposphere. Our experiments suggest a potential shift in the regional moisture balance of West Africa should global radiative forcing continue to increase, highlighting the importance of climate system feedbacks in shaping the response of regional-scale climate to global-scale changes in radiative forcing.

  5. Chaotic examination

    Science.gov (United States)

    Bildirici, Melike; Sonustun, Fulya Ozaksoy; Sonustun, Bahri

    2018-01-01

    In the regards of chaos theory, new concepts such as complexity, determinism, quantum mechanics, relativity, multiple equilibrium, complexity, (continuously) instability, nonlinearity, heterogeneous agents, irregularity were widely questioned in economics. It is noticed that linear models are insufficient for analyzing unpredictable, irregular and noncyclical oscillations of economies, and for predicting bubbles, financial crisis, business cycles in financial markets. Therefore, economists gave great consequence to use appropriate tools for modelling non-linear dynamical structures and chaotic behaviors of the economies especially in macro and the financial economy. In this paper, we aim to model the chaotic structure of exchange rates (USD-TL and EUR-TL). To determine non-linear patterns of the selected time series, daily returns of the exchange rates were tested by BDS during the period from January 01, 2002 to May 11, 2017 which covers after the era of the 2001 financial crisis. After specifying the non-linear structure of the selected time series, it was aimed to examine the chaotic characteristic for the selected time period by Lyapunov Exponents. The findings verify the existence of the chaotic structure of the exchange rate returns in the analyzed time period.

  6. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R; Strasik, Michael [Boeing Research and Technology, PO Box 3707, MC 2T-50, Seattle, WA 98124-2207 (United States)

    2010-12-15

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  7. Concepts for using trapped-flux bulk high-temperature superconductor in motors and generators

    International Nuclear Information System (INIS)

    Hull, John R; Strasik, Michael

    2010-01-01

    We review previous concepts for using bulk high-temperature superconductors (HTSs) in motors and generators and discuss methods for using trapped-flux (TF) HTSs in motors and generators that have been recently investigated in our laboratory. We examine the expected performance of a brushless motor/generator that uses TF bulk HTSs to provide magnetomotive force, where the stator windings are used to create the TF. A key feature is the use of dysprosium for the stator and rotor cores.

  8. Force Modulator System

    Energy Technology Data Exchange (ETDEWEB)

    Redmond Clark

    2009-04-30

    Many metal parts manufacturers use large metal presses to shape sheet metal into finished products like car body parts, jet wing and fuselage surfaces, etc. These metal presses take sheet metal and - with enormous force - reshape the metal into a fully formed part in a manner of seconds. Although highly efficient, the forces involved in forming metal parts also damage the press itself, limit the metals used in part production, slow press operations and, when not properly controlled, cause the manufacture of large volumes of defective metal parts. To date, the metal-forming industry has not been able to develop a metal-holding technology that allows full control of press forces during the part forming process. This is of particular importance in the automotive lightweighting efforts under way in the US automotive manufacturing marketplace. Metalforming Controls Technology Inc. (MC2) has developed a patented press control system called the Force Modulator that has the ability to control these press forces, allowing a breakthrough in stamping process control. The technology includes a series of hydraulic cylinders that provide controlled tonnage at all points in the forming process. At the same time, the unique cylinder design allows for the generation of very high levels of clamping forces (very high tonnages) in very small spaces; a requirement for forming medium and large panels out of HSS and AHSS. Successful production application of these systems testing at multiple stamping operations - including Ford and Chrysler - has validated the capabilities and economic benefits of the system. Although this technology has been adopted in a number of stamping operations, one of the primary barriers to faster adoption and application of this technology in HSS projects is system cost. The cost issue has surfaced because the systems currently in use are built for each individual die as a custom application, thus driving higher tooling costs. This project proposed to better

  9. When aspirations and achievements don't meet. A longitudinal examination of the differential effect of education and occupational attainment on declines in self-rated health among Canadian labour force participants.

    Science.gov (United States)

    Smith, Peter; Frank, John

    2005-08-01

    To examine the association of a mismatch between educational qualifications and occupational attainment and subsequent declines in self-rated health (SRH) in a longitudinal nationally representative Canadian population sample. This study used longitudinal data from 4045 healthy, working respondents of the Canadian National Population Health Survey. Respondents were categorized as either qualified, overqualified, or underqualified based on the match between their education and the skills required for their current occupation over a 2-year period. Logistic regression analysis estimated the odds of decline in SRH over the following 4-year period, using the match between occupation and education as the main independent variable. Analyses were controlled for a number of confounding variables including health behaviours, mental health, self-esteem, job control, and demographic information. Relative to respondents with university education working in occupations for which they were qualified, respondents with university education, working in occupations for which they were overqualified had a significant risk of decline in SRH between 1996 and 2000, even after adjusting for a number of potential confounders (OR = 2.08, 95% CI 1.11-3.91). In respondents with secondary education or less, differences in occupational attainment were not associated with differences in the odds of decline in SRH. The effect of occupational attainment on health is important for individuals who have invested the most time in their education. Conversely, differential occupational attainment is not associated with differences in the odds of decline in health for participants with lower levels of education.

  10. DelPhiForce web server: electrostatic forces and energy calculations and visualization.

    Science.gov (United States)

    Li, Lin; Jia, Zhe; Peng, Yunhui; Chakravorty, Arghya; Sun, Lexuan; Alexov, Emil

    2017-11-15

    Electrostatic force is an essential component of the total force acting between atoms and macromolecules. Therefore, accurate calculations of electrostatic forces are crucial for revealing the mechanisms of many biological processes. We developed a DelPhiForce web server to calculate and visualize the electrostatic forces at molecular level. DelPhiForce web server enables modeling of electrostatic forces on individual atoms, residues, domains and molecules, and generates an output that can be visualized by VMD software. Here we demonstrate the usage of the server for various biological problems including protein-cofactor, domain-domain, protein-protein, protein-DNA and protein-RNA interactions. The DelPhiForce web server is available at: http://compbio.clemson.edu/delphi-force. delphi@clemson.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  11. Self generation, small generation, and embedded generation issues

    International Nuclear Information System (INIS)

    2001-01-01

    The New Brunswick Market Design Committee for electric power restructuring has been directed to examine issues regarding cogeneration and small-scale, on-site generation and how they will fit within the framework of the bilateral contract market. The Committee will also have to deal with issues of generation embedded in a distribution system. The Committee has defined cogeneration as the simultaneous production of electricity and useful thermal energy. Self-generation has been defined as small-scale power generation by an end-user, while embedded generation has been defined as a generation facility that is located within a distribution utility but is not directly connected to the transmission system. The Committee has postponed its decision on whether embedded generation will be eligible to participate under the bilateral contract market for electricity. This report discusses general issues such as the physical support of generation, market support of generation, transition issues and policy issues. It also discusses generation support issues such as operating reserves, transmission tariff issues, and distribution tariffs. Market support issues such as transmission access for generation sales were also considered, along with market access for generation sales, and net metering for behind the meter generation. 7 refs., 1 tab

  12. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  13. Mechanics of mesenchymal contribution to clefting force in branching morphogenesis.

    Science.gov (United States)

    Wan, Xiaohai; Li, Zhilin; Lubkin, Sharon R

    2008-10-01

    Branching morphogenesis is ubiquitous and may involve several different mechanisms. Glandular morphogenesis is affected by growth, cell rearrangements, changes in the basal lamina, changes in the stromal ECM, changes in cell-cell and cell-ECM adhesions, mesenchymal contractility, and possibly other mechanisms. We have developed a 3D model of the mechanics of clefting, focusing in this paper solely on the potential role of mesenchyme-generated traction forces. The tissue mechanics are assumed to be those of fluids, and the hypothesized traction forces are modeled as advected by the deformations which they generate. We find that mesenchymal traction forces are sufficient to generate a cleft of the correct size and morphology, in the correct time frame. We find that viscosity of the tissues affects the time course of morphogenesis, and also affects the resulting form of the organ. Morphology is also strongly dependent on the initial distribution of contractility. We suggest an in vitro method of examining the role of mesenchyme in branching morphogenesis.

  14. Oscillating fluid power generator

    Science.gov (United States)

    Morris, David C

    2014-02-25

    A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure oscillates back and forth, generating lift first in one direction then in the opposite direction. This oscillating movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other oscillating devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given oscillation cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.

  15. Trip generation studies for special generators.

    Science.gov (United States)

    2010-02-01

    This research examines the effects of town centers and senior housing developments on : surrounding roadways and nearby transit. The Institute of Transportation Engineers (ITE) : Trip Generation Manual, which determines number of trips produced or at...

  16. Coffee Cup Atomic Force Microscopy

    Science.gov (United States)

    Ashkenaz, David E.; Hall, W. Paige; Haynes, Christy L.; Hicks, Erin M.; McFarland, Adam D.; Sherry, Leif J.; Stuart, Douglas A.; Wheeler, Korin E.; Yonzon, Chanda R.; Zhao, Jing; Godwin, Hilary A.; Van Duyne, Richard P.

    2010-01-01

    In this activity, students use a model created from a coffee cup or cardstock cutout to explore the working principle of an atomic force microscope (AFM). Students manipulate a model of an AFM, using it to examine various objects to retrieve topographic data and then graph and interpret results. The students observe that movement of the AFM…

  17. Validation of engineering methods for predicting hypersonic vehicle controls forces and moments

    Science.gov (United States)

    Maughmer, M.; Straussfogel, D.; Long, L.; Ozoroski, L.

    1991-01-01

    This work examines the ability of the aerodynamic analysis methods contained in an industry standard conceptual design code, the Aerodynamic Preliminary Analysis System (APAS II), to estimate the forces and moments generated through control surface deflections from low subsonic to high hypersonic speeds. Predicted control forces and moments generated by various control effectors are compared with previously published wind-tunnel and flight-test data for three vehicles: the North American X-15, a hypersonic research airplane concept, and the Space Shuttle Orbiter. Qualitative summaries of the results are given for each force and moment coefficient and each control derivative in the various speed ranges. Results show that all predictions of longitudinal stability and control derivatives are acceptable for use at the conceptual design stage.

  18. StringForce

    DEFF Research Database (Denmark)

    Barendregt, Wolmet; Börjesson, Peter; Eriksson, Eva

    2017-01-01

    In this paper, we present the forced collaborative interaction game StringForce. StringForce is developed for a special education context to support training of collaboration skills, using readily available technologies and avoiding the creation of a "mobile bubble". In order to play StringForce ...

  19. Colice's story and the effects of generational loss.

    Science.gov (United States)

    Sherrod, Melissa McIntire

    2006-11-01

    In 1934, Colice Sayer was forcefully removed from her home and involuntarily committed to a state mental hospital following a legal proceeding she was not allowed to attend. Colice's husband initiated the complaint against her. Colice remained in the institution for 43 years as a ward of the state of New York. This study examined her life to gain an understanding of how the lives of successive generations were altered. The life history method was used to elicit the stories of the central character and her family. Hermeneutic phenomenology was used to gather and analyze the data. Two themes emerged from the data: learned expectations and retreating behaviors. Learned expectations were family rules taught to successive generations. Retreating behaviors were indirect actions observed or obliquely communicated. The loss of a mother by means of forced, legal separation and the subsequent disintegration of the family can pervasively affect successive generations.

  20. Status of Forces and Criminal Jurisdiction

    OpenAIRE

    Voetelink, J.

    2013-01-01

    This article examines the legal status of armed forces present in friendly foreign territory with a special focus on criminal jurisdiction. Traditionally, this issue has been considered from the perspective of public international law in which immunities play an important role. However, this perspective does not fully cover the criminal jurisdiction provisions in the international agreements dealing with the status of visiting forces (Status of Forces Agreements). This article introduces mili...

  1. An Investigation of the Posterior Component of Occlusal Force

    Science.gov (United States)

    1994-05-01

    the dental arch across the midline and examined mandibula deformation in subjects with osseointegrated implants . The authors found that, with maximum...the 58 tongue and cheek musculature. Future studies may consider examining interdental forces between a natural dentition and osseointegrated implants ... dental occlusion forces, and 4. periodontal membrane forces. A stable occlusion would purportedly result when balance in terms of the magnitude

  2. Distributed generation induction and permanent magnet generators

    CERN Document Server

    Lai, L

    2007-01-01

    Distributed power generation is a technology that could help to enable efficient, renewable energy production both in the developed and developing world. It includes all use of small electric power generators, whether located on the utility system, at the site of a utility customer, or at an isolated site not connected to the power grid. Induction generators (IGs) are the cheapest and most commonly used technology, compatible with renewable energy resources. Permanent magnet (PM) generators have traditionally been avoided due to high fabrication costs; however, compared with IGs they are more reliable and productive. Distributed Generation thoroughly examines the principles, possibilities and limitations of creating energy with both IGs and PM generators. It takes an electrical engineering approach in the analysis and testing of these generators, and includes diagrams and extensive case study examples o better demonstrate how the integration of energy sources can be accomplished. The book also provides the ...

  3. Wave Forces on Crown Walls

    DEFF Research Database (Denmark)

    Pedersen, Jan; Burcharth, H. F.

    1993-01-01

    This paper presents some of the results from a large parametric laboratory study including more than 200 long-duration model tests. The study addresses both the wave forces imposed on the breakwater crown wall as well as the performance of the structure in reducing the wave overtopping. The testing...... programme includes variations of the sea state parameters and of the geometrical configuration of the breakwater and crown wall. Basic relations between forces/overtopping and the varied parameters are examined and preliminary design guidelines for structures within the tested range of variations...

  4. Mechanical forces in skin disorders.

    Science.gov (United States)

    Hsu, Chao-Kai; Lin, Hsi-Hui; Harn, Hans I-Chen; Hughes, Michael W; Tang, Ming-Jer; Yang, Chao-Chun

    2018-03-08

    Mechanical forces are known to regulate homeostasis of the skin and play a role in the pathogenesis of skin diseases. The epidermis consists of keratinocytes that are tightly adhered to each other by cell junctions. Defects in keratins or desmosomal/hemidesmosomal proteins lead to the attenuation of mechanical strength and formation of intraepidermal blisters in the case of epidermolysis bullosa simplex. The dermis is rich in extracellular matrix, especially collagen, and provides the majority of tensile force in the skin. Keloid and hypertrophic scar, which is the result of over-production of collagen by fibroblasts during the wound healing, are associated with extrinsic tensile forces and changes of intrinsic mechanical properties of the cell. Increasing evidences shows that stiffness of the skin environment determines the regenerative ability during wound healing process. Mechanotransduction pathways are also involved in the morphogenesis and cyclic growth of hair follicles. The development of androgenetic alopecia is correlated to tensile forces generated by the fibrous tissue underlying the scalp. Acral melanoma predominantly occurs in the weight-bearing area of the foot suggesting the role of mechanical stress. Increased dermal stiffness from fibrosis might be the cause of recessive dystrophic epidermolysis bullosa associated squamous cell carcinoma. Strategies to change the mechanical forces or modify the mechanotransduction signals may lead to a new way to treat skin diseases and promote skin regeneration. Copyright © 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  5. Interfacial force measurements using atomic force microscopy

    NARCIS (Netherlands)

    Chu, L.

    2018-01-01

    Atomic Force Microscopy (AFM) can not only image the topography of surfaces at atomic resolution, but can also measure accurately the different interaction forces, like repulsive, adhesive and lateral existing between an AFM tip and the sample surface. Based on AFM, various extended techniques have

  6. Ground reaction forces and knee kinetics during single and repeated badminton lunges.

    Science.gov (United States)

    Lam, Wing Kai; Ding, Rui; Qu, Yi

    2017-03-01

    Repeated movement (RM) lunge that frequently executed in badminton might be used for footwear evaluation. This study examined the influence of single movement (SM) and RM lunges on the ground reaction forces (GRFs) and knee kinetics during the braking phase of a badminton lunge step. Thirteen male university badminton players performed left-forward lunges in both SM and RM sessions. Force platform and motion capturing system were used to measure GRFs and knee kinetics variables. Paired t-test was performed to determine any significant differences between SM and RM lunges regarding mean and coefficient of variation (CV) in each variable. The kinetics results indicated that compared to SM lunges, the RM lunges had shorter contact time and generated smaller maximum loading rate of impact force, peak knee anterior-posterior force, and peak knee sagittal moment but generated larger peak horizontal resultant forces (Ps forces (Ps < 0.05). These results suggested that the RM testing protocols had a distinct loading response and adaptation pattern during lunge and that the RM protocol showed higher within-trial reliability, which may be beneficial for the knee joint loading evaluation under different interventions.

  7. Proprioception is Robust under External Forces

    NARCIS (Netherlands)

    Kuling, I.A.; Brenner, E.; Smeets, J.B.J.

    2013-01-01

    Information from cutaneous, muscle and joint receptors is combined with efferent information to create a reliable percept of the configuration of our body (proprioception). We exposed the hand to several horizontal force fields to examine whether external forces influence this percept. In an

  8. Parametrization of open systems with effective quadratic hamiltonians plus stochastic force

    International Nuclear Information System (INIS)

    Hernandez, E.S.; Mizrahi, S.S.

    1981-12-01

    The evolution generated by general dissipative Hamiltonians is analyzed when a stochastic force is included. A mapping technique allows to easily write the equations of motion for the observables of interest. A general dissipativity condition is extracted, whose fullfilment guarantees that thermal equilibrium is reached as the final stage of the evolution. Several existing frictional Hamiltonians are examined and it is seen that the correlation of the fluctuating force is essential to the destruction of a constant of motion inherent to pure quantal behaviour. (Author) [pt

  9. Examining Cyber Command Structures

    Science.gov (United States)

    2015-03-01

    Debate with Renewed Relevance (Carlisle Barracks, PA: U.S. Army War College, 2002), 1; John D. Cinnamon , U.S. Department of the Space Force: A...Washington, DC: Joint Chiefs of Staff, 2014. Cinnamon , John D. U.S. Department of the Space Force: A Necessary Evolution. Norfolk, VA: Joint Forces Staff

  10. Tomorrow's Work Force: New Values in the Workplace.

    Science.gov (United States)

    Deutsch, R. Eden

    1985-01-01

    A new generation of workers is entering the work force. The "computer babies," fiercely independent, will demand autonomy on the job and will brush aside many of the values of the older baby-boom generation. (RM)

  11. Dynamic Commitment: Wargaming Projected Forces Against the QDR Defense Strategy

    National Research Council Canada - National Science Library

    Carter, Clarence

    1997-01-01

    .... The Dynamic Commitment Wargame Series informed participants regarding the expected future demand on forces, such that Services were better able to articulate the effect of the examined force options...

  12. Challenging Forced Marriage: Building the Defence and Support ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Forced marriage violates the principles of personal freedom and individual autonomy. It is viewed as a human rights violation under international human rights law. This project will generate evidence that will help combat forced marriage in India on two key issues: shelters for women resisting forced marriage and a law to ...

  13. Acoustic radiation force impulse of the liver

    Science.gov (United States)

    D’Onofrio, Mirko; Crosara, Stefano; De Robertis, Riccardo; Canestrini, Stefano; Demozzi, Emanuele; Gallotti, Anna; Pozzi Mucelli, Roberto

    2013-01-01

    Acoustic radiation force impulse (ARFI) imaging is a new and promising ultrasound-based diagnostic technique that, evaluating the wave propagation speed, allows the assessment of the tissue stiffness. ARFI is implemented in the ultrasound scanner. By short-duration acoustic radiation forces (less than 1 ms), localized displacements are generated in a selected region of interest not requiring any external compression so reducing the operator dependency. The generated wave scan provides qualitative or quantitative (wave velocity values) responses. Several non-invasive methods for assessing the staging of fibrosis are used, in order to avoid liver biopsy. Liver function tests and transient elastography are non-invasive, sensitive and accurate tools for the assessment of liver fibrosis and for the discrimination between cirrhotic and non-cirrhotic liver. Many published studies analyse ARFI performance and feasibility in studying diffuse liver diseases and compare them to other diagnostic imaging modalities such as conventional ultrasonography and transient elastography. Solid focal liver lesions, both benign and malignant, are common findings during abdominal examinations. The accurate characterization and differential diagnosis are important aims of all the imaging modalities available today. Only few papers describe the application of ARFI technology in the study of solid focal liver lesions, with different results. In the present study, the existing literature, to the best of our knowledge, about ARFI application on diffuse and focal liver pathology has been evaluated and results and statistical analyses have been compared, bringing to the conclusion that ARFI can be used in the study of the liver with similar accuracy as transient elastography in diagnosing significant fibrosis or cirrhosis and has got some advantages in respect to transient elastography since it does not require separate equipment, better displays anatomical structures and measurements can be

  14. An Examination of the Mediating Effect of Acculturation on the Relationship between Parenting Style, Academic Experience, and Resilience among Second and Third Generations West Indian College Students and Their Families

    Science.gov (United States)

    Greene, Makeda Jacqueline

    2017-01-01

    With the increase of West Indian families of African descent acculturating into new communities and cultivating spaces for their cultures and customs to flourish, there is an increased significance for continued quantitative analyses to examine the cultural patterns, values and practices that take place within the West Indian familial structures…

  15. Labor Force Participation Rate

    Data.gov (United States)

    City and County of Durham, North Carolina — This thematic map presents the labor force participation rate of working-age people in the United States in 2010. The 2010 Labor Force Participation Rate shows the...

  16. Aerodynamic Lifting Force.

    Science.gov (United States)

    Weltner, Klaus

    1990-01-01

    Describes some experiments showing both qualitatively and quantitatively that aerodynamic lift is a reaction force. Demonstrates reaction forces caused by the acceleration of an airstream and the deflection of an airstream. Provides pictures of demonstration apparatus and mathematical expressions. (YP)

  17. Correlation of fingertip shear force direction with somatosensory cortical activity in monkey

    Science.gov (United States)

    Fortier-Poisson, Pascal; Langlais, Jean-Sébastien

    2015-01-01

    To examine the activity of somatosensory cortex (S1) neurons to self-generated shear forces on the index and thumb, two monkeys were trained to grasp a stationary metal tab with a key grip and exert forces without the fingers slipping in one of four orthogonal directions for 1 s. A majority (∼85%) of slowly adapting and rapidly adapting (RA) S1 neurons had activity modulated with shear force direction. The cells were recorded mainly in areas 1 and 2 of the S1, although some area 3b neurons also responded to shear direction or magnitude. The preferred shear vectors were distributed in every direction, with tuning arcs varying from 50° to 170°. Some RA neurons sensitive to dynamic shear force direction also responded to static shear force but within a narrower range, suggesting that the direction of the shear force may influence the adaptation rate. Other neurons were modulated with shear forces in diametrically opposite directions. The directional sensitivity of S1 cortical neurons is consistent with recordings from cutaneous afferents showing that shear direction, even without slip, is a powerful stimulus to S1 neurons. PMID:26467520

  18. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  19. Acoustic force spectroscopy

    NARCIS (Netherlands)

    Sitters, G.; Kamsma, D.; Thalhammer, G.; Ritsch-Marte, M.; Peterman, E.J.G.; Wuite, G.J.L.

    2015-01-01

    Force spectroscopy has become an indispensable tool to unravel the structural and mechanochemical properties of biomolecules. Here we extend the force spectroscopy toolbox with an acoustic manipulation device that can exert forces from subpiconewtons to hundreds of piconewtons on thousands of

  20. Forces in General Relativity

    Science.gov (United States)

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  1. Generation of high order modes

    CSIR Research Space (South Africa)

    Ngcobo, S

    2012-07-01

    Full Text Available This work deals with the generation of symmetrical high order Laguerre Gaussian modes. These high order Laguerre-Gaussian beams are generated by forcing the laser using an annular binary Diffractive Optical Element whose geometry is in connection...

  2. Royal Danish Air Force. Air Operations Doctrine

    DEFF Research Database (Denmark)

    Nørby, Søren

    This brief examines the development of the first Danish Air Force Air Operations Doctrine, which was officially commissioned in October 1997 and remained in effect until 2010. The development of a Danish air power doctrine was heavily influenced by the work of Colonel John Warden (USAF), both...... through his book ”The Air Campaign” and his subsequent planning of the air campaign against Iraq in 1990-1991. Warden’s ideas came to Denmark and the Danish Air Force by way of Danish Air Force students attending the United States Air Force Air University in Alabama, USA. Back in Denmark, graduates from...... the Air University inspired a small number of passionate airmen, who then wrote the Danish Air Operations Doctrine. The process was supported by the Air Force Tactical Command, which found that the work dovetailed perfectly with the transformation process that the Danish Air Force was in the midst...

  3. Entropy-generated power and its efficiency

    DEFF Research Database (Denmark)

    Golubeva, N.; Imparato, A.; Esposito, M.

    2013-01-01

    We propose a simple model for a motor that generates mechanical motion by exploiting an entropic force arising from the topology of the underlying phase space. We show that the generation of mechanical forces in our system is surprisingly robust to local changes in kinetic and topological paramet...

  4. A synthetic peptide corresponding to the C-terminal 25 residues of phage MS2 coded lysis protein dissipates the protonmotive force in Escherichia coli membrane vesicles by generating hydrophilic pores

    NARCIS (Netherlands)

    Goessens, Wil H.F.; Driessen, Arnold J.M.; Wilschut, Jan; Duin, Jan van

    1988-01-01

    The RNA phage MS2 encodes a protein, 75 amino acids long, that is necessary and sufficient for lysis of the host cell. DNA deletion analysis has shown that the lytic activity is confined to the C-terminal half of the protein. We have examined the effects of a synthetic peptide, covering the

  5. Generational diversity.

    Science.gov (United States)

    Kramer, Linda W

    2010-01-01

    Generational diversity has proven challenges for nurse leaders, and generational values may influence ideas about work and career planning. This article discusses generational gaps, influencing factors and support, and the various generational groups present in today's workplace as well as the consequences of need addressing these issues. The article ends with a discussion of possible solutions.

  6. Statistics of force networks

    Science.gov (United States)

    Tighe, Brian

    2009-03-01

    We study the statistics of contact forces in the force network ensemble, a minimal model of jammed granular media that emphasizes the role of vector force balance. We show that the force probability distribution can be calculated analytically by way of an analogy to equilibrium ensemble methods. In two dimensions the large force tail decays asymptotically as a Gaussian, distinct from earlier predictions, due to the existence of a conserved quantity related to the presence of local vector force balance. We confirm our predictions with highly accurate statistical sampling -- we sample the force distribution over more than 40 decades -- permitting unambiguous confrontation of theory with numerics. We show how the conserved quantity arises naturally within the context of any constant stress ensemble.

  7. Quantum fictitious forces

    DEFF Research Database (Denmark)

    Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder

    2002-01-01

    We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii......) a singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number...... of atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

  8. An overview of advanced power generation technologies

    International Nuclear Information System (INIS)

    Gardner, D.; Shaw, P.

    1993-01-01

    This paper is intended as a brief review of the technologies currently applied in Australian electricity generation and the technologies which are likely to be employed in the future. The paper opens with a review of the primary energy resources available for the generation of electricity in Australia, and the technologies currently employed. The development of advanced generation technologies around the world is reviewed, and the most likely technologies to be employed in Australia are described. There are a number of renewable and alternative technologies, such as generation from sewage digester, landfill or mine gases. Their impact would, however, be disproportionate because of the strong climate forcing effect of methane. Of the wide range of other emerging renewable technologies examined, solar thermal offers the best prospect of maturing into a financially-competitive technology for large scale generation in the next 20 years. However, will remain unable to compete with non-renewable technologies in normal financial terms, at least until 2005 and probably well beyond that date. Generation using the fission of nuclear fuels is a mature, proven technology. Based on the most likely fuel and other assumptions made in this study, the costs of nuclear generation are only moderately higher than conventional coal-fired options. Nuclear generation is thus a relatively low cost route to reductions in carbon dioxide emission for new plant, at $19/tonne CO 2 saved, in comparison with conventional black coal technology, and $13/tonne CO 2 compared with conventional brown coal firing. While major considerations of societal acceptance clearly exist, nuclear generation has the necessary technical and financial qualifications for serious consideration as an element in any greenhouse strategy. 5 tab., 2 figs

  9. R5FORCE: a program to compute fluid induced forces using hydrodynamic output from the RELAP5 code

    International Nuclear Information System (INIS)

    Watkins, J.C.

    1983-01-01

    This paper describes the computer code R5FORCE, a postprocessor to the RELAP5/MOD1 thermal-hydraulics code. R5FORCE computes piping hydraulic force/time histories that can be input into various structural analysis computer codes. R5FORCE solves the momentum conservation equation using the pressure and wall shear force terms rather than the pressure and fluid acceleration terms; eliminating potential instabilities associated with computing the time derivative in the fluid acceleration term. The updates to REALP5 required to generate the input data to R5FORCE are also discussed

  10. The five competitive forces that shape strategy.

    Science.gov (United States)

    Porter, Michael E

    2008-01-01

    In 1979, a young associate professor at Harvard Business School published his first article for HBR, "How Competitive Forces Shape Strategy." In the years that followed, Michael Porter's explication of the five forces that determine the long-run profitability of any industry has shaped a generation of academic research and business practice. In this article, Porter undertakes a thorough reaffirmation and extension of his classic work of strategy formulation, which includes substantial new sections showing how to put the five forces analysis into practice. The five forces govern the profit structure of an industry by determining how the economic value it creates is apportioned. That value may be drained away through the rivalry among existing competitors, of course, but it can also be bargained away through the power of suppliers or the power of customers or be constrained by the threat of new entrants or the threat of substitutes. Strategy can be viewed as building defenses against the competitive forces or as finding a position in an industry where the forces are weaker. Changes in the strength of the forces signal changes in the competitive landscape critical to ongoing strategy formulation. In exploring the implications of the five forces framework, Porter explains why a fast-growing industry is not always a profitable one, how eliminating today's competitors through mergers and acquisitions can reduce an industry's profit potential, how government policies play a role by changing the relative strength of the forces, and how to use the forces to understand complements. He then shows how a company can influence the key forces in its industry to create a more favorable structure for itself or to expand the pie altogether. The five forces reveal why industry profitability is what it is. Only by understanding them can a company incorporate industry conditions into strategy.

  11. Generation Y Perspectives

    Science.gov (United States)

    Skytland, Nicholas; Painting, Kristen; Barrera, Aaron; Fitzpatrick, Garret

    2008-01-01

    This viewgraph presentation reviews the perception of NASA and the importance of engaging those people born between 1977 and 2000, also known as Generation Y. It examines some of the differences in attitudes and experiences, and how it reflects on how they view NASA. It also discusses use of the internet in connecting to the people from that generation.

  12. The nature of motive force

    CERN Document Server

    Pramanick, Achintya Kumar

    2014-01-01

    In this monograph Prof. Pramanick explicates the law of motive force, a fundamental law of nature that can be observed and appreciated as an addition to the existing laws of thermodynamics. This unmistakable and remarkable tendency of nature is equally applicable to all other branches of studies. He first conceptualized the law of motive force in 1989, when he was an undergraduate student. Here he reports various applications of the law in the area of  thermodynamics, heat transfer, fluid mechanics and solid mechanics, and shows how it is possible to solve analytically century-old unsolved problems through its application. This book offers a comprehensive account of the law and its relation to other laws and principles, such as the generalized conservation principle, variational formulation, Fermat’s principle, Bejan’s constructal law, entropy generation minimization, Bejan’s method of intersecting asymptotes and equipartition principle. Furthermore, the author addresses some interrelated fundamental p...

  13. Maternal Endogenous Forces and Shoulder Dystocia.

    Science.gov (United States)

    Grimm, Michele J

    2016-12-01

    Childbirth is a complicated biomechanical process that many take for granted. However, the delivery forces generated by a mother (uterine contractions and maternal pushing) are strong and have a significant effect on the body and tissues of the fetus, especially during the second stage of labor. Although most infants are born without negative, force-related outcomes, in some infants the normal forces of labor cause an injury that can have either temporary or permanent sequelae. The biomechanical situation is further complicated when an infant's shoulder impacts the maternal pelvis, which provides increased resistance and creates added stresses within the neonatal body and tissues.

  14. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

    Directory of Open Access Journals (Sweden)

    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  15. Learning to produce predicted static handgrip forces.

    Science.gov (United States)

    Angyán, L; Téczely, T; Karsai, I

    2005-01-01

    The objective of this study was to prove the hypothesis that kinaesthetic sensations, without visual or verbal guidance, give sufficient information to produce predictive handgrip forces. The ability of 70 girls and 70 boys aged 11 to 17 years to produce predicted static handgrip force was examined. The subjects were requested to produce 50% of their individual maximum handgrip force and maintain it for 2 seconds without visual control. Ten trials were done first by the right-hand and then by the left-hand. The maximum grip strength increased parallel with age, but significant differences were found between both the right and the left-hand, and the genders. Close correlations were found between the desired and the exerted forces. The differences between the desired forces and the exerted forces produced by the fifth trials were significantly smaller than that of the first trials. The verbal information about each exerted force contributed to the learning with right-hand since it caused a further decrease in the difference between the desired force and the exerted force. In contrast, the learning with left-hand was not enhanced by verbal feedback. These results suggest that kinaesthetic feedback information from the hand plays an effective role in learning to produce predicted grip strengths without visual and verbal information.

  16. Handbook of force transducers. Principles and components

    Energy Technology Data Exchange (ETDEWEB)

    Stefanescu, Dan Mihai [Romanian Measurement Society, Bucharest (Romania)

    2011-07-01

    Part I introduces the basic ''Principles and Methods of Force Measurement'' according to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ''(Strain Gauge) Force Transducers Components'', evolving from the classical force transducer to the digital / intelligent one, with the incorporation of three subsystems (sensors, electromechanics and informatics). The elastic element (EE) is the ''heart'' of the force transducer and basically determines its performance. A 12-type elastic element classification is proposed (stretched / compressed column or tube, bending beam, bending and/or torsion shaft, middle bent bar with fixed ends, shear beam, bending ring, yoke or frame, diaphragm, axial-stressed torus, axisymmetrical and voluminous EE), with emphasis on the optimum location of the strain gauges. The main properties of the associated Wheatstone bridge, best suited for the parametrical transducers, are examined, together with the appropriate electronic circuits for SGFTs. The handbook fills a gap in the field of Force Measurement, both experts and newcomers, no matter of their particular interest, finding a lot of useful and valuable subjects in the area of Force Transducers; in fact, it is the first specialized monograph in this inter- and multidisciplinary field. (orig.)

  17. Naval Reserve Force: Cost and Benefit Analysis of Reducing the Number of Naval Surface Reserve Force Operating Budget Holders

    National Research Council Canada - National Science Library

    Young, Eric

    1997-01-01

    .... This thesis examines one of Commander Naval Surface Reserve Force's initiatives for reducing the current number of Operating Budget holder's Comptroller Departments without sacrificing efficiency...

  18. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  19. RSOI: Force Deployment Bottleneck

    National Research Council Canada - National Science Library

    D'Amato, Mark

    1998-01-01

    This study uses The Theory Of Constraints (TOC) management methodology and recent military missions to show that RSOI operations are generally the limiting constraint to force deployment operations...

  20. Bi-Force

    DEFF Research Database (Denmark)

    Sun, Peng; Speicher, Nora K; Röttger, Richard

    2014-01-01

    outperformed existing tools with Bi-Force at least when following the evaluation protocols from Eren et al. Bi-Force is implemented in Java and integrated into the open source software package of BiCluE. The software as well as all used datasets are publicly available at http://biclue.mpi-inf.mpg.de....... of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...

  1. Intermolecular and surface forces

    CERN Document Server

    Israelachvili, Jacob N

    2011-01-01

    This reference describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This third edition is expanded into three sections and contains five new chapters over the previous edition.· starts fr

  2. Macroscopic forces from supersymmetry

    CERN Document Server

    Dimopoulos, Savas K

    1996-01-01

    We argue that theories in which supersymmetry breaking originates at low energies often contain scalar particles that mediate coherent gravitational strength forces at distances less than a cm. We estimate the strength and range of these forces in several cases. Present limits on such forces are inadequate. However new techniques, such as those based on small cryogenic mechanical oscillators, may improve the present limits by ten orders of magnitude or discover new forces as weak as 1 \\% of gravity at distances down to 40 microns.

  3. Technical-economical study of heat and energy generation and distribution systems: application to the tertiary sector; Etude technico-economique des systemes de production et distribution de chaleur et de force: application au tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Romary, D.

    2001-10-01

    The liberalization of energy markets and the related competition between energy suppliers has led to the introduction of a multitude of tariff offers, among which the end-user encounters difficulties to find his way. The aim of this work is to model this problem and to develop a 'global' control tool which integrates the hot water and electricity consumptions of the user, his energy generation and distribution facilities and his gas and power subscriptions. The potential cost saving is evidenced by three types of studies: the first one consists in determining the optimal subscriptions with the existing consumption profiles; the second one proposes a peak shaving of part of the consumptions and defines the optimal operations and subscriptions; the third one proposes a partial obliteration of the consumptions through the integration of a cogeneration system and localizes the optimal operations and subscriptions. The results of these three studies are discussed according to sensibility studies which integrate energy consumptions and prices disturbances. The databases included in the model allow to analyze different examples taken in the tertiary sector (office building, hospital, university, airport, supermarket, district heating system, small industry etc..). The results obtained demonstrate the relevance for the end-user of this decision-aid tool. (J.S.)

  4. Instant Generation

    Science.gov (United States)

    Loveland, Elaina

    2017-01-01

    Generation Z students (born between 1995-2010) have replaced millennials on college campuses. Generation Z students are entrepreneurial, desire practical skills with their education, and are concerned about the cost of college. This article presents what need to be known about this new generation of students.

  5. Isotope generator

    International Nuclear Information System (INIS)

    1979-01-01

    The patent describes an isotope generator incorporating the possibility of stopping elution before the elution vessel is completely full. Sterile ventilation of the whole system can then occur, including of both generator reservoir and elution vessel. A sterile, and therefore pharmaceutically acceptable, elution fluid is thus obtained and the interior of the generator is not polluted with non-sterile air. (T.P.)

  6. Two-Dimensional Lorentz Force Image Reconstruction for Magnetoacoustic Tomography with Magnetic Induction

    International Nuclear Information System (INIS)

    Yi-Ling, Li; Zhen-Bo, Liu; Xia-Sheng, Guo; Dong, Zhang; Qing-Yu, Ma

    2010-01-01

    Magnetoacoustic tomography with magnetic induction has shown potential applications in imaging the electrical impedance for biological tissues. We present a novel methodology for the inverse problem solution of the 2-D Lorentz force distribution reconstruction based on the acoustic straight line propagation theory. The magnetic induction and acoustic generation as well as acoustic detection are theoretically provided as explicit formulae and also validated by the numerical simulations for a multilayered cylindrical phantom model. The reconstructed 2-D Lorentz force distribution reveals not only the conductivity configuration in terms of shape and size but also the amplitude value of the Lorentz force in the examined layer. This study provides a basis for further study of conductivity distribution reconstruction of MAT-MI in medical imaging. (fundamental areas of phenomenology (including applications))

  7. Weapons of Mass Destruction and Domestic Force Protection: Basic Response Capability for Military, Police & Security Forces

    National Research Council Canada - National Science Library

    Manto, Samuel

    1999-01-01

    ... actions to improve preparedness. This paper examines what a minimum basic response capability for all military, police and security forces should be to ensure at least some chance for their own survival and possible early warning...

  8. Validating Proposed Learning Progressions on Force and Motion Using the Force Concept Inventory: Findings from Singapore Secondary Schools

    Science.gov (United States)

    Fulmer, Gavin W.

    2015-01-01

    This study examines the validity of 2 proposed learning progressions on the force concept when tested using items from the Force Concept Inventory (FCI). This is the first study to compare students' performance with respect to learning progressions both for force and motion and for Newton's third law in parallel. It is also among the first studies…

  9. In vivo recording of aerodynamic force with an aerodynamic force platform: from drones to birds.

    Science.gov (United States)

    Lentink, David; Haselsteiner, Andreas F; Ingersoll, Rivers

    2015-03-06

    Flapping wings enable flying animals and biomimetic robots to generate elevated aerodynamic forces. Measurements that demonstrate this capability are based on experiments with tethered robots and animals, and indirect force calculations based on measured kinematics or airflow during free flight. Remarkably, there exists no method to measure these forces directly during free flight. Such in vivo recordings in freely behaving animals are essential to better understand the precise aerodynamic function of their flapping wings, in particular during the downstroke versus upstroke. Here, we demonstrate a new aerodynamic force platform (AFP) for non-intrusive aerodynamic force measurement in freely flying animals and robots. The platform encloses the animal or object that generates fluid force with a physical control surface, which mechanically integrates the net aerodynamic force that is transferred to the earth. Using a straightforward analytical solution of the Navier-Stokes equation, we verified that the method is accurate. We subsequently validated the method with a quadcopter that is suspended in the AFP and generates unsteady thrust profiles. These independent measurements confirm that the AFP is indeed accurate. We demonstrate the effectiveness of the AFP by studying aerodynamic weight support of a freely flying bird in vivo. These measurements confirm earlier findings based on kinematics and flow measurements, which suggest that the avian downstroke, not the upstroke, is primarily responsible for body weight support during take-off and landing.

  10. Climate forcings and feedbacks

    Science.gov (United States)

    Hansen, James

    1993-01-01

    Global temperature has increased significantly during the past century. Understanding the causes of observed global temperature change is impossible in the absence of adequate monitoring of changes in global climate forcings and radiative feedbacks. Climate forcings are changes imposed on the planet's energy balance, such as change of incoming sunlight or a human-induced change of surface properties due to deforestation. Radiative feedbacks are radiative changes induced by climate change, such as alteration of cloud properties or the extent of sea ice. Monitoring of global climate forcings and feedbacks, if sufficiently precise and long-term, can provide a very strong constraint on interpretation of observed temperature change. Such monitoring is essential to eliminate uncertainties about the relative importance of various climate change mechanisms including tropospheric sulfate aerosols from burning of coal and oil smoke from slash and burn agriculture, changes of solar irradiance changes of several greenhouse gases, and many other mechanisms. The considerable variability of observed temperature, together with evidence that a substantial portion of this variability is unforced indicates that observations of climate forcings and feedbacks must be continued for decades. Since the climate system responds to the time integral of the forcing, a further requirement is that the observations be carried out continuously. However, precise observations of forcings and feedbacks will also be able to provide valuable conclusions on shorter time scales. For example, knowledge of the climate forcing by increasing CFC's relative to the forcing by changing ozone is important to policymakers, as is information on the forcing by CO2 relative to the forcing by sulfate aerosols. It will also be possible to obtain valuable tests of climate models on short time scales, if there is precise monitoring of all forcings and feedbacks during and after events such as a large volcanic eruption

  11. Phalanx force magnitude and trajectory deviation increased during power grip with an increased coefficient of friction at the hand-object interface.

    Science.gov (United States)

    Enders, Leah R; Seo, Na Jin

    2011-05-17

    This study examined the effect of friction between the hand and grip surface on a person's grip strategy and force generation capacity. Twelve young healthy adults performed power grip exertions on an instrumented vertical cylinder with the maximum and 50% of maximum efforts (far above the grip force required to hold the cylinder), while normal and shear forces at each phalanx of all five fingers in the direction orthogonal to the gravity were recorded. The cylinder surface was varied for high-friction rubber and low-friction paper coverings. An increase in surface friction by replacing the paper covering with the rubber covering resulted in 4% greater mean phalanx normal force (perpendicular to the cylinder surface) and 22% greater mean phalanx shear force in either the proximal or distal direction of the digits (pfriction with the rubber surface compared to the paper surface was associated with a 20% increase in the angular deviation of the phalanx force from the direction normal to the cylinder surface (p<0.05). This study demonstrates that people significantly changed the magnitude and direction of phalanx forces depending on the surface they gripped. Such change in the grip strategy appears to help increase grip force generation capacity. This finding suggests that a seemingly simple power grip exertion involves sensory feedback-based motor control, and that people's power grip capacity may be reduced in cases of numbness, glove use, or injuries resulting in reduced sensation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Physicists' Forced Migrations under Hitler

    Science.gov (United States)

    Beyerchen, Alan

    2011-03-01

    When the Nazis came to power in early 1933 they initiated formal and informal measures that forced Jews and political opponents from public institutions such as universities. Some physicists retired and others went into industry, but most emigrated. International communication and contact made emigration a viable option despite the desperate economic times in the Great Depression. Another wave of emigrations followed the annexation of Austria in 1938. Individual cases as well as general patterns of migration and adaptation to new environments will be examined in this presentation. One important result of the forced migrations was that many of the physicists expelled under Hitler played important roles in strengthening physics elsewhere, often on the Allied side in World War II.

  13. Jaw-muscle force and excursion scale with negative allometry in platyrrhine primates.

    Science.gov (United States)

    Taylor, Andrea B; Yuan, Tian; Ross, Callum F; Vinyard, Christopher J

    2015-07-14

    Platyrrhines span two orders of magnitude in body size and are characterized by diverse feeding behaviors and diets. While size plays an important role in primate feeding behavior and masticatory apparatus morphology, we know little about size-correlated changes in the force-generating (physiologic cross-sectional area; PCSA) and excursion/stretch (fiber length; L f ) capabilities of the jaw-closing muscles in platyrrhines. We examined scaling relationships of the superficial masseter and temporalis muscles in 21 platyrrhine species. Previous work suggests that larger platyrrhines are at a mechanical disadvantage for generating bite forces compared with smaller platyrrhines. We hypothesize that scaling of jaw-muscle fiber architecture counters this size-correlated decrease in mechanical advantage. Thus, we predicted that jaw-muscle PCSAs and muscle weights scale with positive allometry while L f s scale with negative allometry, relative to load-arm estimates for incisor/molar biting and chewing. Jaw-muscle PCSAs and L f s appear to scale with negative allometry relative to load-arm estimates and body size. Negative allometry of jaw-muscle weights partially accounts for the size-correlated decreases in PCSA and L f . Estimates of bite force also scale with negative allometry. Large-bodied platyrrhines (e.g., Alouatta) are at a relative disadvantage for generating jaw-muscle and bite force as well as jaw-muscle stretch, compared with smaller species (e.g., Callithrix). The net effect is that larger platyrrhines likely produce relatively smaller maximal bite forces compared with smaller taxa. Relative to small- and intermediate-sized platyrrhines, large-bodied platyrrhines feed on some of the least mechanically challenging foods, consistent with the size-correlated decrease in relative muscle and bite forces across the clade. Am J Phys Anthropol, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. Elementary Particles and Forces.

    Science.gov (United States)

    Quigg, Chris

    1985-01-01

    Discusses subatomic particles (quarks, leptons, and others) revealed by higher accelerator energies. A connection between forces at this subatomic level has been established, and prospects are good for a description of forces that encompass binding atomic nuclei. Colors, fundamental interactions, screening, camouflage, electroweak symmetry, and…

  15. The forces in Nature

    CERN Multimedia

    CERN AC

    1998-01-01

    The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies of phenomena in which they have a dominant role.

  16. Forces in yeast flocculation

    Science.gov (United States)

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2015-01-01

    In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

  17. A novel hydraulic force standard machine

    Science.gov (United States)

    McIlraith, A. H.; Clarkson, M. T.

    2002-12-01

    A hydraulic force standard machine covering the range 40 kN-1.5 MN has been designed, built and tested. Preliminary measurements indicate that this force standard can be self-calibrated to a relative standard uncertainty of 1 × 10-4 or better and is linear to 0.31 kN. The design of this force standard is suitable for much larger machines generating forces up to 20 MN. The special features of this machine include the use of controlled clearance for the limitation of oil flow, thus enabling the generation of high pressures and large forces, the use of journal bearings external to the high-pressure region to give high stiffness against side thrusts, and a method of calibration that involves determining the slope of the curve force versus pressure. This calibration procedure is essentially a null method that is largely independent of load cell properties such as hysteresis, creep, long-term drift and state of calibration, in contrast to current build-up calibration techniques that are strongly dependent on load cell properties.

  18. Steam generator life management

    International Nuclear Information System (INIS)

    Tapping, R.L.; Nickerson, J.; Spekkens, P.; Maruska, C.

    1998-01-01

    Steam generators are a critical component of a nuclear power reactor, and can contribute significantly to station unavailability, as has been amply demonstrated in Pressurized Water Reactors (PWRs). CANDU steam generators are not immune to steam generator degradation, and the variety of CANDU steam generator designs and tube materials has led to some unexpected challenges. However, aggressive remedial actions, and careful proactive maintenance activities, have led to a decrease in steam generator-related station unavailability of Canadian CANDUs. AECL and the CANDU utilities have defined programs that will enable existing or new steam generators to operate effectively for 40 years. Research and development work covers corrosion and mechanical degradation of tube bundles and internals, chemistry, thermal hydraulics, fouling, inspection and cleaning, as well as provision for specially tool development for specific problem solving. A major driving force is development of CANDU-specific fitness-for-service guidelines, including appropriate inspection and monitoring technology to measure steam generator condition. Longer-range work focuses on development of intelligent on-line monitoring for the feedwater system and steam generator. New designs have reduced risk of corrosion and fouling, are more easily inspected and cleaned, and are less susceptible to mechanical damage. The Canadian CANDU utilities have developed programs for remedial actions to combat degradation of performance (Gentilly-2, Point Lepreau, Bruce A/B, Pickering A/B), and have developed strategic plans to ensure that good future operation is ensured. This report shows how recent advances in cleaning technology are integrated into a life management strategy, discusses downcomer flow measurement as a means of monitoring steam generator condition, and describes recent advances in hideout return as a life management tool. The research and development program, as well as operating experience, has identified

  19. Nonequilibrium forces between dragged ultrasoft colloids.

    Science.gov (United States)

    Singh, Sunil P; Winkler, Roland G; Gompper, Gerhard

    2011-10-07

    The dynamical deformation of ultrasoft colloids as well as their dynamic frictional forces are numerically investigated, when one colloid is dragged past another at constant velocity. Hydrodynamic interactions are captured by a particle-based mesoscopic simulation method. At vanishing relative velocity, the equilibrium repulsive force-distance curve is obtained. At large drag velocities, in contrast, we find an apparent attractive force for departing colloids along the dragging direction. The deformation, in the close encounter of colloids, and the energy dissipation are examined as a function of the drag velocity and their separation.

  20. Analysis of applied forces and electromyography of back and shoulders muscles when performing a simulated hand scaling task.

    Science.gov (United States)

    Porter, William; Gallagher, Sean; Torma-Krajewski, Janet

    2010-05-01

    Hand scaling is a physically demanding task responsible for numerous overexertion injuries in underground mining. Scaling requires the miner to use a long pry bar to remove loose rock, reducing the likelihood of rock fall injuries. The experiments described in this article simulated "rib" scaling (scaling a mine wall) from an elevated bucket to examine force generation and electromyographic responses using two types of scaling bars (steel and fiberglass-reinforced aluminum) at five target heights ranging from floor level to 176 cm. Ten male and six female subjects were tested in separate experiments. Peak and average force applied at the scaling bar tip and normalized electromyography (EMG) of the left and right pairs of the deltoid and erectores spinae muscles were obtained. Work height significantly affected peak prying force during scaling activities with highest force capacity at the lower levels. Bar type did not affect force generation. However, use of the lighter fiberglass bar required significantly more muscle activity to achieve the same force. Results of these studies suggest that miners scale points on the rock face that are below their knees, and reposition the bucket as often as necessary to do so. Published by Elsevier Ltd.

  1. Hydrophobic-hydrophilic forces in protein folding.

    Science.gov (United States)

    Durell, Stewart R; Ben-Naim, Arieh

    2017-08-01

    The process of protein folding is obviously driven by forces exerted on the atoms of the amino-acid chain. These forces arise from interactions with other parts of the protein itself (direct forces), as well as from interactions with the solvent (solvent-induced forces). We present a statistical-mechanical formalism that describes both these direct and indirect, solvent-induced thermodynamic forces on groups of the protein. We focus on 2 kinds of protein groups, commonly referred to as hydrophobic and hydrophilic. Analysis of this result leads to the conclusion that the forces on hydrophilic groups are in general stronger than on hydrophobic groups. This is then tested and verified by a series of molecular dynamics simulations, examining both hydrophobic alkanes of different sizes and hydrophilic moieties represented by polar-neutral hydroxyl groups. The magnitude of the force on assemblies of hydrophilic groups is dependent on their relative orientation: with 2 to 4 times larger forces on groups that are able to form one or more direct hydrogen bonds. © 2017 Wiley Periodicals, Inc.

  2. Nanoindentation and atomic force microscopy measurements on ...

    Indian Academy of Sciences (India)

    The films were deposited on silicon (111) substrates at various process conditions, e.g. substrate bias voltage (B) and nitrogen partial pressure. Mechanical properties of the coatings were investigated by a nanoindentation technique. Force vs displacement curves generated during loading and unloading of a Berkovich ...

  3. Active Magnetic Bearings – Magnetic Forces

    DEFF Research Database (Denmark)

    Kjølhede, Klaus

    2006-01-01

    Parameter identification procedures and model validation are major steps towards intelligent machines supported by active magnetic bearings (AMB). The ability of measuring the electromagnetic bearing forces, or deriving them from measuring the magnetic flux, strongly contributes to the model...... of the work is the characterization of magnetic forces by using two experimental different experimental approaches. Such approaches are investigated and described in details. A special test rig is designed where the 4 poles - AMB is able to generate forces up to 1900 N. The high precision characterization...... of the magnetic forces are led by using different experimental tests: (I) by using hall sensors mounted directly on the poles (precise measurements of the magnetic flux) and by an auxiliary system, composed of strain gages and flexible beams attached to the rotor; (II) by measuring the input current and bearing...

  4. Parameterized examination in econometrics

    Science.gov (United States)

    Malinova, Anna; Kyurkchiev, Vesselin; Spasov, Georgi

    2018-01-01

    The paper presents a parameterization of basic types of exam questions in Econometrics. This algorithm is used to automate and facilitate the process of examination, assessment and self-preparation of a large number of students. The proposed parameterization of testing questions reduces the time required to author tests and course assignments. It enables tutors to generate a large number of different but equivalent dynamic questions (with dynamic answers) on a certain topic, which are automatically assessed. The presented methods are implemented in DisPeL (Distributed Platform for e-Learning) and provide questions in the areas of filtering and smoothing of time-series data, forecasting, building and analysis of single-equation econometric models. Questions also cover elasticity, average and marginal characteristics, product and cost functions, measurement of monopoly power, supply, demand and equilibrium price, consumer and product surplus, etc. Several approaches are used to enable the required numerical computations in DisPeL - integration of third-party mathematical libraries, developing our own procedures from scratch, and wrapping our legacy math codes in order to modernize and reuse them.

  5. Motivating the Generations: Economic and Educational Influences

    Science.gov (United States)

    Herley, Wade

    2009-01-01

    This paper examines the various generations that include the greatest generation, the baby-boomers, generation X, and generation Y. The research encompasses many motivational elements that each generation covets, rejects, or shares. These generations are at different stages in life and each plays a vital role within our society. The workforce has…

  6. OOTW Force Design Tools

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.E.; Hartley, D.S.III; Packard, S.L.

    1999-05-01

    This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

  7. Forced magnetic reconnection

    Science.gov (United States)

    Vekstein, G.

    2017-10-01

    This is a tutorial-style selective review explaining basic concepts of forced magnetic reconnection. It is based on a celebrated model of forced reconnection suggested by J. B. Taylor. The standard magnetohydrodynamic (MHD) theory of this process has been pioneered by Hahm & Kulsrud (Phys. Fluids, vol. 28, 1985, p. 2412). Here we also discuss several more recent developments related to this problem. These include energetics of forced reconnection, its Hall-mediated regime, and nonlinear effects with the associated onset of the secondary tearing (plasmoid) instability.

  8. Rate of force development

    DEFF Research Database (Denmark)

    Maffiuletti, Nicola A; Aagaard, Per; Blazevich, Anthony J

    2016-01-01

    development and to discuss various methodological considerations inherent to its evaluation for research and clinical purposes. Rate of force development (1) seems to be mainly determined by the capacity to produce maximal voluntary activation in the early phase of an explosive contraction (first 50-75 ms......The evaluation of rate of force development during rapid contractions has recently become quite popular for characterising explosive strength of athletes, elderly individuals and patients. The main aims of this narrative review are to describe the neuromuscular determinants of rate of force...

  9. Interfacial forces in aqueous media

    CERN Document Server

    van Oss, Carel J

    2006-01-01

    Thoroughly revised and reorganized, the second edition of Interfacial Forces in Aqueous Media examines the role of polar interfacial and noncovalent interactions among biological and nonbiological macromolecules as well as biopolymers, particles, surfaces, cells, and both polar and apolar polymers. The book encompasses Lifshitz-van der Waals and electrical double layer interactions, as well as Lewis acid-base interactions between colloidal entities in polar liquids such as water. New in this Edition: Four previously unpublished chapters comprising a new section on interfacial propertie

  10. BILATERAL GROUND REACTION FORCES AND JOINT MOMENTS FOR LATERAL SIDESTEPPING AND CROSSOVER STEPPING TASKS

    Directory of Open Access Journals (Sweden)

    William I. Sellers

    2009-03-01

    Full Text Available Racquet sports have high levels of joint injuries suggesting the joint loads during play may be excessive. Sports such as badminton employ lateral sidestepping (SS and crossover stepping (XS movements which so far have not been described in terms of biomechanics. This study examined bilateral ground reaction forces and three dimensional joint kinetics for both these gaits in order to determine the demands of the movements on the leading and trailing limb and predict the contribution of these movements to the occurrence of overuse injury of the lower limbs. A force platform and motion-analysis system were used to record ground reaction forces and track marker trajectories of 9 experienced male badminton players performing lateral SS, XS and forward running tasks at a controlled speed of 3 m·s-1 using their normal technique. Ground reaction force and kinetic data for the hip, knee and ankle were analyzed, averaged across the group and the biomechanical variables compared. In all cases the ground reaction forces and joint moments were less than those experienced during moderate running suggesting that in normal play SS and XS gaits do not lead to high forces that could contribute to increased injury risk. Ground reaction forces during SS and XS do not appear to contribute to the development of overuse injury. The distinct roles of the leading and trailing limb, acting as a generator of vertical force and shock absorber respectively, during the SS and XS may however contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury. However it is still possible that faulty use of these gaits might lead to high loads and this should be the subject of future work

  11. Generative Semantics.

    Science.gov (United States)

    King, Margaret

    The first section of this paper deals with the attempts within the framework of transformational grammar to make semantics a systematic part of linguistic description, and outlines the characteristics of the generative semantics position. The second section takes a critical look at generative semantics in its later manifestations, and makes a case…

  12. Generative collectives

    NARCIS (Netherlands)

    van Osch, W.; Avital, M.; Sabherwal, R.; Sumner, M.

    2010-01-01

    Analyzing generative group activities against the backdrop of an increasingly connected world, this theory development paper introduces the concept of "generative collectives" as a new framework for classifying internet-based collectives and a novel theoretical lens for explaining why some

  13. Generational Phenomenology

    African Journals Online (AJOL)

    denise

    by Xers, and how Millennials not only accept but expect diversity (320 ff.). However, nothing is actually said to the effect that generational relations might be affected by the different styles of thinking, speaking, and values of women. Moreover, it seems likely that generations and their relations are different for people of color,.

  14. Sound generator

    NARCIS (Netherlands)

    Berkhoff, Arthur P.

    2008-01-01

    A sound generator, particularly a loudspeaker, configured to emit sound, comprising a rigid element (2) enclosing a plurality of air compartments (3), wherein the rigid element (2) has a back side (B) comprising apertures (4), and a front side (F) that is closed, wherein the generator is provided

  15. Sound generator

    NARCIS (Netherlands)

    Berkhoff, Arthur P.

    2010-01-01

    A sound generator, particularly a loudspeaker, configured to emit sound, comprising a rigid element (2) enclosing a plurality of air compartments (3), wherein the rigid element (2) has a back side (B) comprising apertures (4), and a front side (F) that is closed, wherein the generator is provided

  16. Pulse Generator

    Science.gov (United States)

    Greer, Lawrence (Inventor)

    2017-01-01

    An apparatus and a computer-implemented method for generating pulses synchronized to a rising edge of a tachometer signal from rotating machinery are disclosed. For example, in one embodiment, a pulse state machine may be configured to generate a plurality of pulses, and a period state machine may be configured to determine a period for each of the plurality of pulses.

  17. Sound generator

    NARCIS (Netherlands)

    Berkhoff, Arthur P.

    2007-01-01

    A sound generator, particularly a loudspeaker, configured to emit sound, comprising a rigid element (2) enclosing a plurality of air compartments (3), wherein the rigid element (2) has a back side (B) comprising apertures (4), and a front side (F) that is closed, wherein the generator is provided

  18. Generative Semantics

    Science.gov (United States)

    Bagha, Karim Nazari

    2011-01-01

    Generative semantics is (or perhaps was) a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of…

  19. Contribution of hand and foot force to take-off velocity for the kick-start in competitive swimming.

    Science.gov (United States)

    Takeda, Tsuyoshi; Sakai, Shin; Takagi, Hideki; Okuno, Keisuke; Tsubakimoto, Shozo

    2017-03-01

    This study examines the hand and foot reaction force recorded independently while performing the kick-start technique. Eleven male competitive swimmers performed three trials for the kick-start with maximum effort. Three force platforms (main block, backplate and handgrip) were used to measure reaction forces during starting motion. Force impulses from the hands, front foot and rearfoot were calculated via time integration. During the kick-start, the vertical impulse from the front foot was significantly higher than that from the rearfoot and the horizontal impulse from the rearfoot was significantly higher than that from the front foot. The force impulse from the front foot was dominant for generating vertical take-off velocity and the force impulse from the rearfoot was dominant for horizontal take-off velocity. The kick-start's shorter block time in comparison to prior measurements of the grab start was explained by the development of horizontal reaction force from the hands and the rearfoot at the beginning of the starting motion.

  20. Postmodern Chapel Services for Generation X and Millennial Generation Soldiers

    Science.gov (United States)

    2008-06-13

    TERMS Chapels, Chaplains, Postmodern, Postmodernism, Generations, Generation X, Millenial Generation, Emergent Chruch, Emerging Churches, Seeker...new trends . Chapter One has six sections that introduce the problem, research question, assumptions, definitions, delimitations, and significance of... trending in any direction? Who are the majority of soldiers? 2 Society demographics. What is known about that majority from examining the

  1. Objective Force Warrior

    National Research Council Canada - National Science Library

    Shisler, Vernon

    2001-01-01

    This presentation concerns technology aimed at the dismounted soldier, Capstone demonstrations for FY06-07, fielding in the Objective Force time frame, strong interest in a lightweight weapon family...

  2. Packing force data correlations

    International Nuclear Information System (INIS)

    Heiman, S.M.

    1994-01-01

    One of the issues facing valve maintenance personnel today deals with an appropriate methodology for installing and setting valve packing that will minimize leak rates, yet ensure functionality of the the valve under all anticipated operating conditions. Several variables can affect a valve packing's ability to seal, such as packing bolt torque, stem finish, and lubrication. Stem frictional force can be an excellent overall indicator of some of the underlying conditions that affect the sealing characteristics of the packing and the best parameter to use when adjusting the packing. This paper addresses stem friction forces, analytically derives the equations related to these forces, presents a methodology for measuring these forces on valve stems, and attempts to correlate the data directly to the underlying variables

  3. Hanscom Air Force Base

    Data.gov (United States)

    Federal Laboratory Consortium — MIT Lincoln Laboratory occupies 75 acres (20 acres of which are MIT property) on the eastern perimeter of Hanscom Air Force Base, which is at the nexus of Lexington,...

  4. On the fifth forces

    Science.gov (United States)

    Treder, Hans-Jürgen

    1991-03-01

    We discuss the possibility of “fifth forces” in relativistic gravitation theories of fourth order. The fifth force may be an analog to the “weak forces” in the theories of electroweak interactions.

  5. Examining the media as channels of conflict generation | Osong ...

    African Journals Online (AJOL)

    A survey was adopted, using fifty (50) respondents from three media houses: the Nigeria Television Authority, NTA; the Cross River Broadcasting Corporation, CRBC; Hit FM, a private radio station located in Calabar and lecturers of Mass Communication Studies, the University of Calabar, Unical; and the Cross River ...

  6. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    1987-05-01

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes

  7. Bow Crushing Forces

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    1996-01-01

    The purpose of these notes is to present a basis for the estimation of the internal collision forces between conventinal merchant vessels and large volume offshore structures in the form of gravity-supported offshore installations and bridges crossing international shipping routes.The main emphasis...... is on the presentation of impact loads on fixed offshore structures due to bow collisions. The crushing forces are determined as functions of vessels size, vessels speed, bow profile, collision angles and eccentric impacts....

  8. Security Force Assistance

    Science.gov (United States)

    2009-05-01

    Group 8-59. Cultures may be individualistic or collectivist in their orientation. An individualist culture is one in which the ties between...relatively little weight on offensive and defensive operations from a U.S. perspective . However, when U.S. forces accompany foreign security forces (FSF) in...precedence when conducting SFA. As a result, the brigade combat team (BCT) may be a supported command from a U.S. perspective as well as acting as

  9. Joint Force Fires Coordination: Towards a Joint Force Answer

    National Research Council Canada - National Science Library

    Fearn, William

    1997-01-01

    .... Components compete for decisive effect not only with each other but with the joint force. The contemporary joint force is confederated, the joint force headquarters a weak arbitration authority...

  10. Comparison of the initial orthodontic force systems produced by a new lingual bracket system and a straight-wire appliance.

    Science.gov (United States)

    Fuck, Lars-Michael; Wiechmann, Dirk; Drescher, Dieter

    2005-09-01

    Over the last few years, lingual appliances have become an established orthodontic treatment technique. Many studies have concentrated on various esthetic aspects, on laboratory and clinical procedures, and on patient comfort and compliance. The orthodontic force systems of these appliances, however, have not yet been investigated. The aim of this study was thus to determine the forces and moments produced by a new lingual bracket system during the leveling phase of orthodontic treatment and to compare those with the corresponding force system of a labial straight-wire appliance. The intra-oral situation of ten patients undergoing orthodontic treatment was replicated in measurement casts fitted with lingual and labial brackets. Special care was taken to precisely reproduce each patient's interbracket geometry. We measured each tooth's force systems as generated by a leveling arch inserted into the lingual and labial brackets. The resulting force systems of both appliances were found to be quite similar with regard to the magnitude of most force and moment components. Only the first molars were subjected to considerably greater single forces with the lingual appliance. Tipping moments were found to be significantly smaller with the lingual technique, whereas the rotational moments were significantly smaller with the labial appliance. All in all we noted significant differences between the two techniques only in certain areas which upon closer examination were distributed over only a few tooth types. The initial force systems produced by the new lingual bracket system proved to be comparable with those delivered by a conventional straight-wire appliance. The actual levels of forces and moments, however, were found in certain cases to be too heavy with both techniques. We therefore recommend the development of leveling wires producing considerably lighter forces and moments.

  11. Variable Acceleration Force Calibration System (VACS)

    Science.gov (United States)

    Rhew, Ray D.; Parker, Peter A.; Johnson, Thomas H.; Landman, Drew

    2014-01-01

    Conventionally, force balances have been calibrated manually, using a complex system of free hanging precision weights, bell cranks, and/or other mechanical components. Conventional methods may provide sufficient accuracy in some instances, but are often quite complex and labor-intensive, requiring three to four man-weeks to complete each full calibration. To ensure accuracy, gravity-based loading is typically utilized. However, this often causes difficulty when applying loads in three simultaneous, orthogonal axes. A complex system of levers, cranks, and cables must be used, introducing increased sources of systematic error, and significantly increasing the time and labor intensity required to complete the calibration. One aspect of the VACS is a method wherein the mass utilized for calibration is held constant, and the acceleration is changed to thereby generate relatively large forces with relatively small test masses. Multiple forces can be applied to a force balance without changing the test mass, and dynamic forces can be applied by rotation or oscillating acceleration. If rotational motion is utilized, a mass is rigidly attached to a force balance, and the mass is exposed to a rotational field. A large force can be applied by utilizing a large rotational velocity. A centrifuge or rotating table can be used to create the rotational field, and fixtures can be utilized to position the force balance. The acceleration may also be linear. For example, a table that moves linearly and accelerates in a sinusoidal manner may also be utilized. The test mass does not have to move in a path that is parallel to the ground, and no re-leveling is therefore required. Balance deflection corrections may be applied passively by monitoring the orientation of the force balance with a three-axis accelerometer package. Deflections are measured during each test run, and adjustments with respect to the true applied load can be made during the post-processing stage. This paper will

  12. An Enduring Framework for Assessing the Contributions of Force Structure to a Coercive Strategy

    National Research Council Canada - National Science Library

    Beene, Eric

    2002-01-01

    .... With a strategy and force structure review occurring on average every two years, the military has still not been able to generate a consistent basis on which to justify its force structure or its strategy...

  13. Flywheel Generator

    OpenAIRE

    Yuniarsih, Pratitis; Bachtiyar, Fahmi; Rosyidin, Mufti; Prabawanto, Trisakti

    2014-01-01

    Lately, the needs of energy is increasing but its availability is very limited. Therefore,it is important to do more research on energy reform. Generator is one of the alternative energy which commonly used by the public, but it has a minus value such as the voltage instability and low efficiency of the generator . Based on those issues,so we made an application flywheel in electrical generator, which aims to produce a concept of power efficiency increase, stabilize the output voltage of the ...

  14. Entropy Generation in Steady Laminar Boundary Layers with Pressure Gradients

    Directory of Open Access Journals (Sweden)

    Donald M. McEligot

    2014-07-01

    Full Text Available In an earlier paper in Entropy [1] we hypothesized that the entropy generation rate is the driving force for boundary layer transition from laminar to turbulent flow. Subsequently, with our colleagues we have examined the prediction of entropy generation during such transitions [2,3]. We found that reasonable predictions for engineering purposes could be obtained for flows with negligible streamwise pressure gradients by adapting the linear combination model of Emmons [4]. A question then arises—will the Emmons approach be useful for boundary layer transition with significant streamwise pressure gradients as by Nolan and Zaki [5]. In our implementation the intermittency is calculated by comparison to skin friction correlations for laminar and turbulent boundary layers and is then applied with comparable correlations for the energy dissipation coefficient (i.e., non-dimensional integral entropy generation rate. In the case of negligible pressure gradients the Blasius theory provides the necessary laminar correlations.

  15. Traction force dynamics predict gap formation in activated endothelium

    International Nuclear Information System (INIS)

    Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L.

    2016-01-01

    In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

  16. Traction force dynamics predict gap formation in activated endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L., E-mail: p.hordijk@vumc.nl

    2016-09-10

    In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

  17. Issues related to choosing a guard force structure

    International Nuclear Information System (INIS)

    Averbach, C.; Cusack, J.; Green, L.; Higinbotham, W.; Indusi, J.; Marcuse, W.; Weinstock, E.

    1975-01-01

    The establishment of a federal security force has been suggested as an additional step to protect nuclear material. The force would be given the responsibility for guarding nuclear facilities and shipments of nuclear materials. A study to identify the issues that are relevant to choosing between the private guard forces that are presently employed by industry or a guard force under federal authority is summarized. To examine the issues which would be relevant, three possible types of security force structures were selected for comparison: a federal force under central authority, a private guard force employed by or under contract to a facility, and a private arrangement to employ local police officers similar to the arrangement for armed guards at airports. The issues were divided into seven categories: (1) legal considerations, (2) liability, (3) staffing and operations, (4) costs, (5) relationship to off-site forces, (6) management and control, and (7) transportation. (U.S.)

  18. Graph Generator Survey

    Energy Technology Data Exchange (ETDEWEB)

    Lothian, Joshua [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Sarah S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sullivan, Blair D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baker, Matthew B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schrock, Jonathan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Poole, Stephen W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2013-10-01

    The benchmarking effort within the Extreme Scale Systems Center at Oak Ridge National Laboratory seeks to provide High Performance Computing benchmarks and test suites of interest to the DoD sponsor. The work described in this report is a part of the effort focusing on graph generation. A previously developed benchmark, SystemBurn, allowed the emulation of different application behavior profiles within a single framework. To complement this effort, similar capabilities are desired for graph-centric problems. This report examines existing synthetic graph generator implementations in preparation for further study on the properties of their generated synthetic graphs.

  19. Steam-Generator Integrity Program/Steam-Generator Group Project

    International Nuclear Information System (INIS)

    1982-10-01

    The Steam Generator Integrity Program (SGIP) is a comprehensive effort addressing issues of nondestructive test (NDT) reliability, inservice inspection (ISI) requirements, and tube plugging criteria for PWR steam generators. In addition, the program has interactive research tasks relating primary side decontamination, secondary side cleaning, and proposed repair techniques to nondestructive inspectability and primary system integrity. The program has acquired a service degraded PWR steam generator for research purposes. This past year a research facility, the Steam Generator Examination Facility (SGEF), specifically designed for nondestructive and destructive examination tasks of the SGIP was completed. The Surry generator previously transported to the Hanford Reservation was then inserted into the SGEF. Nondestructive characterization of the generator from both primary and secondary sides has been initiated. Decontamination of the channelhead cold leg side was conducted. Radioactive field maps were established in the steam generator, at the generator surface and in the SGEF

  20. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    1993-01-01

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining licensees and applicants for reactor operator and senior reactor operator licenses at power reactor facilities pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). The Examiner Standards are intended to assist NRC examiners and facility licensees to better understand the initial and requalification examination processes and to ensure the equitable and consistent administration of examinations to all applicants. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator licensing policy changes

  1. Unfolding of globular polymers by external force

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Samuel; Terentjev, Eugene M., E-mail: emt1000@cam.ac.uk [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2015-11-14

    We examine the problem of a polymer chain, folded into a globule in poor solvent, subjected to a constant tensile force. Such a situation represents a Gibbs thermodynamic ensemble and is useful for analysing force-clamp atomic force microscopy measurements, now very common in molecular biophysics. Using a basic Flory mean-field theory, we account for surface interactions of monomers with solvent. Under an increasing tensile force, a first-order phase transition occurs from a compact globule to a fully extended chain, in an “all-or-nothing” unfolding event. This contrasts with the regime of imposed extension, first studied by Halperin and Zhulina [Europhys. Lett. 15, 417 (1991)], where there is a regime of coexistence of a partial globule with an extended chain segment. We relate the transition forces in this problem to the solvent quality and degree of polymerisation, and also find analytical expressions for the energy barriers present in the problem. Using these expressions, we analyse the kinetic problem of a force-ramp experiment and show that the force at which a globule ruptures depends on the rate of loading.

  2. Experimental Studies of Explosively-Driven Magnetohydrodynamic Generators

    National Research Council Canada - National Science Library

    Agee, F

    1997-01-01

    .... Explosive magnetohydrodynamic (MHD) generators are electrical power sources, which convert the kinetic energy of moving plasma into useful electrical energy through the magnetic portion of the Lorentz force...

  3. Generating ethnographic research questions

    DEFF Research Database (Denmark)

    Friberg, Torbjörn

    2015-01-01

    As part of recent complex transformations, it seems that higher educational organisations are being forced to reorganise, standardise and streamline in order to survive in the new political and economic context. How are ethnographers in general going to approach these contemporary phenomena......? By drawing on the conceptual history of anthropology, the aim of this article is to generate ethnographic-oriented research questions concerned with higher education. The first part of the article provides an ethnographic background, while the second part focuses on Paul Willis's reasoning on ethnographic...

  4. From static to animated: Measuring mechanical forces in tissues.

    Science.gov (United States)

    Nelson, Celeste M

    2017-01-02

    Cells are physical objects that exert mechanical forces on their surroundings as they migrate and take their places within tissues. New techniques are now poised to enable the measurement of cell-generated mechanical forces in intact tissues in vivo, which will illuminate the secret dynamic lives of cells and change our current perception of cell biology. © 2017 Nelson.

  5. Spin motive forces due to magnetic vortices and domain walls

    NARCIS (Netherlands)

    Lucassen, M.E.; Kruis, G.C.F.L.; Lavrijsen, R.; Swagten, H.J.M.; Koopmans, B.; Duine, R.A.

    2011-01-01

    We study spin motive forces, that is, spin-dependent forces and voltages induced by time-dependent magnetization textures, for moving magnetic vortices and domain walls. First, we consider the voltage generated by a one-dimensional field-driven domain wall. Next, we perform detailed calculations on

  6. Force generation of bio-inspired hover kinematics

    NARCIS (Netherlands)

    Vandenheede, R.B.R.; Bernal, L.P.; Morrison, C.L.; Humbert, S.

    2012-01-01

    This paper presents the results of an experimental study of the aerodynamics of an elliptical flap plate wing in pitch-plunge motion. Several wing motion kinematics are derived from the kinematics of the Agrius Convolvuli (hawk moth) in hover. The experiments are conducted at a Reynolds number of 4,

  7. Generating ordered Si nanocrystals via atomic force microscopy

    Czech Academy of Sciences Publication Activity Database

    Verveniotis, Elisseos; Šípek, Emil; Stuchlík, Jiří; Kočka, Jan; Rezek, Bohuslav

    2012-01-01

    Roč. 358, č. 17 (2012), 2118–2121 ISSN 0022-3093 R&D Projects: GA ČR GD202/09/H041; GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : AFM * CS-AFM * a-Si:H * electric crystallization * nickel Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.597, year: 2012

  8. Pedestrian-induced lateral forces on footbridges

    DEFF Research Database (Denmark)

    Ingolfsson, Einar Thor; Georgakis, Christos T.; Jönsson, Jeppe

    2012-01-01

    This paper investigates the phenomenon of excessive pedestrian-induced lateral vibrations as observed on several high-profile footbridges. The vibrations are a consequence of human-structure interaction, in which the forces generated by the pedestrians depend strongly on the vibration of the unde......This paper investigates the phenomenon of excessive pedestrian-induced lateral vibrations as observed on several high-profile footbridges. The vibrations are a consequence of human-structure interaction, in which the forces generated by the pedestrians depend strongly on the vibration...... of the underlying pavement. An extensive experimental analysis has been carried out to determine the lateral forces generated by pedestrians when walking on a laterally moving treadmill. Two different conditions are investigated; initially the treadmill is fixed and then it is laterally driven in a sinusoidal...... motion at varying combinations of frequencies (0.33-1.07 Hz) and amplitudes (4.5-48 mm). The component of the pedestrian-induced force which is caused by the laterally moving surface is herewith quantified through equivalent velocity and acceleration proportional coefficients. It is shown that large...

  9. Pedestrian-induced lateral forces on footbridges

    DEFF Research Database (Denmark)

    Ingólfsson, Einar Thór; Georgakis, Christos T.; Jönsson, Jeppe

    2011-01-01

    This paper investigates the phenomenon of excessive pedestrian-induced lateral vibrations as observed on several high-profile footbridges. The vibrations are a consequence of human-structure interaction, in which the forces generated by the pedestrians depend strongly on the vibration of the unde......This paper investigates the phenomenon of excessive pedestrian-induced lateral vibrations as observed on several high-profile footbridges. The vibrations are a consequence of human-structure interaction, in which the forces generated by the pedestrians depend strongly on the vibration...... of the underlying pavement. An extensive experimental analysis has been carried out to determine the lateral forces generated by pedestrians when walking on a laterally moving treadmill. Two different conditions are investigated; initially the treadmill is fixed and then it is laterally driven in a sinusoidal...... motion at varying combinations of frequencies (0.33-1.07 Hz) and amplitudes (4.5-48 mm). The component of the pedestrian-induced force which is caused by the laterally moving surface is herewith quantified through equivalent velocity and acceleration proportional coefficients. It is shown that large...

  10. Lateral force transmission between human tendon fascicles

    DEFF Research Database (Denmark)

    Haraldsson, Bjarki T; Aagaard, Per; Qvortrup, Klaus

    2008-01-01

    Whether adjacent collagen fascicles transmit force in parallel is unknown. The purpose of the present study was to examine the magnitude of lateral force transmission between adjacent collagen fascicles from the human patellar and Achilles tendon. From each sample two adjacent strands of fascicles...... in the patellar and Achilles tendon fascicles, respectively. A decline in stiffness of 39% and 60% from cycle 1 to cycle 2, and of 93% and 100% from cycle 2 to cycle 3 was observed in the patellar and Achilles tendon fascicles, respectively. The present data demonstrate that lateral force transmission between...... adjacent collagen fascicles in human tendons is small or negligible, suggesting that tendon fascicles largely act as independent structures and that force transmission principally takes place within the individual fascicles....

  11. Force production in the rugby union scrum.

    Science.gov (United States)

    Quarrie, K L; Wilson, B D

    2000-04-01

    In this study, we examined the relationship between anthropometric, strength and power characteristics of rugby forwards, their body position when scrummaging, and their ability to apply force when scrummaging. Force applied to an instrumented scrum machine was measured for 56 players, both individually and as scrum packs. Measurements of body position for individuals were made by digitizing videotape records of the trials. Forty players subsequently had their anthropometry assessed and completed several strength and power tests. Body mass, each component of somatotype, maximal anaerobic power developed on a cycle ergometer, and isokinetic knee extension strength correlated significantly with individual scrummaging force. A regression model (P scrum pack to develop technique and coordination as a unit to maximize scrummaging force.

  12. Automobile dependence: The irresistible force

    Energy Technology Data Exchange (ETDEWEB)

    Kenworthy, J.; Newman, P. [Murdoch Univ., WA (Australia). Inst. for Science and Technology Policy

    1993-08-01

    The proposition by Charles Lave that the automobile is `unstoppable`, an irresistible force` and that transit has `lost the battle` in the US and is losing it in Europe, is examined in this paper. It also examines Lave`s proposition that, despite this power of the automobile, car use in the US will probably plateau because of saturation in car ownership, and therefore it may be possible to expand the US highway network without new roads immediately filling up, as they have done until now. The paper presents 1990/91 data on private and public transport for US, Australian, European and Asian cities and updates previously published data. The update to 1990 is attempting to see the extent to which these patterns are continuing or changing in different cities. Overall the paper finds that although automobile dependence is a powerful force, it is not `irresistible` or `unstoppable` and it is certainly not an inevitable outcome of growing wealth. (author). 7 tabs., 17 figs., refs.

  13. Design and Implementation of Nonlinear Force Controllers for Friction Stir Welding Processes

    Science.gov (United States)

    2009-02-01

    In the path force controller implementation, a constant path force is maintained, even in the presence of gaps, and wormhole generation during the...set of experiments is designed to demonstrate the ability of the path force controller to eliminate the generation of wormholes during the welding...reference value of 0.22 kN. The reference path force is selected so a good weld will be obtained without wormholes or the creation of surface voids

  14. Measuring Single-Bond Rupture Forces Using High Electric Fields in Microfluidic Channels and DNA Oligomers as Force Tags

    OpenAIRE

    Breisch, Stefanie; Gonska, Julian; Deissler, Helmut; Stelzle, Martin

    2005-01-01

    The disruption force of specific biotin-streptavidin bonds was determined using DNA oligomers as force tags. Forces were generated by an electric field acting on a biotinylated fluorescently labeled DNA oligomer. DNA oligomers were immobilized via biotin-streptavidin bonds on the walls of microfluidic channels. Channel layout and fluid-based deposition process were designed to enable well-defined localized deposition of the oligomers in a narrow gap of the microchannel. Electric fields of up ...

  15. Examining the Assessment Literacy of External Examiners

    Science.gov (United States)

    Medland, Emma

    2015-01-01

    External scrutiny of higher education courses is evident globally, but the use of an external examiner from another institution for the purposes of quality assurance has been a distinguishing feature of UK higher education since the 1830s. However, the changing higher education context has led to mounting criticism of the system and the…

  16. Examining Competition in Ontario's Higher Education Market

    Science.gov (United States)

    Farhan, Bayan Yousef

    2017-01-01

    Financial challenges have forced many publicly funded academic institutions in Ontario to adopt a corporate model and to use market tools to compete in the higher education market and maintain their enrolment and revenue levels. This study has analyzed how competition affects publicly funded universities in Ontario. Competition was examined by…

  17. Trial manufacture of rotary friction tester and frictional force measurement of metals

    CERN Document Server

    Abe, T; Kanari, M; Tanzawa, S

    2002-01-01

    In the plasma confinement type fusion reactor, in-vessel structures such as a blanket module slide at the joints each other when plasma disruption occurs, and then frictional heat is generated there. Therefore, for the selection of material and the use as the design data, it is important to understand the frictional characteristics of metals and ceramic films in the vacuum. In the present study, we have manufactured a prototype of rotary friction tester and examined the performances of the tester. The frictional characteristics of metals in the room air was measured using the friction tester, and the results obtained are as follows. A drifting friction force for a constant time and a friction force during the idling were 98 mN and 225 mN, respectively. These values were sufficiently small as compared to pressing load (9.8 - 57.8 N) used in the friction test. In a friction force measurement of stainless steel, dynamic friction force obeyed Amontons' law which indicated that dynamic friction force is not depend...

  18. Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions.

    Science.gov (United States)

    Fulford, Jonathan; Winyard, Paul G; Vanhatalo, Anni; Bailey, Stephen J; Blackwell, Jamie R; Jones, Andrew M

    2013-04-01

    Dietary nitrate supplementation, which enhances nitric oxide (NO) bioavailability, has previously been shown to contribute to improved exercise performance by reducing both oxygen cost and energy expenditure. In contrast, previous studies have indicated that NO can lower force production in vitro. To examine the role of dietary nitrates in regulating force generation under normal physiological conditions, we undertook an extended nitrate supplementation regime and determined force output and energy cost with a repeated isometric maximum voluntary contraction (MVC) protocol. In a double-blind, randomized, crossover design, eight participants received 0.5 l/day of nitrate-rich (BR) or nitrate-depleted (PL) beetroot juice for 15 days and completed an exercise protocol consisting of 50 MVCs at 2.5 h, 5 days and 15 days after the beginning of the supplementation period. No significant reduction in force output was determined for BR relative to PL for the peak contraction, the mean or the end force, and no significant time effect was found over the course of the supplementation period. There was a reduction in the mean PCr cost of exercise averaged over the BR supplementation trials, but this did not reach statistical significance for end exercise (BR 15.10 ± 4.14 mM, PL 17.10 ± 5.34 mM, P = 0.06) or the mean throughout the protocol (BR 15.96 ± 4.14 mM, PL 17.79 ± 4.51 mM, P = 0.06). However, a significant reduction in PCr cost per unit force output was found for BR at end exercise (P = 0.04). These results indicate that, under normal physiological conditions, increased NO bioavailability is not associated with a reduction of force-generating capability in human skeletal muscle and confirm that nitrate supplementation reduces the PCr cost of force production.

  19. A linear magnetic motor and generator

    Science.gov (United States)

    Studer, P. A.

    1980-01-01

    In linear magnetic motor and generator suitable for remote and hostile environments, magnetic forces drive reciprocating shaft along its axis. Actuator shaft is located in center of cylindrical body and may be supported by either contacting or noncontacting bearings. When device operates as bidirectional motor, drive coil selectively adds and subtracts magnetic flux to and from flux paths, producing forces that drive actuator along axis. When actuator is driven by external reciprocating engine, device becomes ac generator.

  20. Chaos as an intermittently forced linear system.

    Science.gov (United States)

    Brunton, Steven L; Brunton, Bingni W; Proctor, Joshua L; Kaiser, Eurika; Kutz, J Nathan

    2017-05-30

    Understanding the interplay of order and disorder in chaos is a central challenge in modern quantitative science. Approximate linear representations of nonlinear dynamics have long been sought, driving considerable interest in Koopman theory. We present a universal, data-driven decomposition of chaos as an intermittently forced linear system. This work combines delay embedding and Koopman theory to decompose chaotic dynamics into a linear model in the leading delay coordinates with forcing by low-energy delay coordinates; this is called the Hankel alternative view of Koopman (HAVOK) analysis. This analysis is applied to the Lorenz system and real-world examples including Earth's magnetic field reversal and measles outbreaks. In each case, forcing statistics are non-Gaussian, with long tails corresponding to rare intermittent forcing that precedes switching and bursting phenomena. The forcing activity demarcates coherent phase space regions where the dynamics are approximately linear from those that are strongly nonlinear.The huge amount of data generated in fields like neuroscience or finance calls for effective strategies that mine data to reveal underlying dynamics. Here Brunton et al.develop a data-driven technique to analyze chaotic systems and predict their dynamics in terms of a forced linear model.

  1. Free piston linear generator for low grid power generation

    Directory of Open Access Journals (Sweden)

    Abdalla Izzeldin

    2017-01-01

    Full Text Available Generating power is of great importance nowadays across the world. However, recently, the world became aware of the climatic changes due to the greenhouse effect caused by CO2 emissions and began seeking solutions to reduce the negative impact on the environment. Besides, the exhaustion of fossil fuels and their environmental impact, make it is crucial to develop clean energy sources, and efforts are focused on developing and improving the efficiency of all energy consuming systems. The tubular permanent magnet linear generators (TPMLGs are the best candidate for energy converters. Despite being suffering problem of attraction force between permanent magnets and stator teeth, to eliminate such attraction force, ironless-stator could be considered. Thus, they could waive the presence of any magnetic attraction between the moving and stator part. This paper presents the design and analysis of ironless -cored TPMLG for low grid power generation. The main advantages of this generator are the low cogging force and high efficiency. Therefore, the magnetic field computation of the proposed generator has been performed by applying a magnetic vector potential and utilizing a 2-D finite element analysis (FEA. Moreover, the experimental results for the current profile, pressure profile and velocity profile have been presented.

  2. Turning the ECOWAS Standby Force in a More Proactive Force: An Analysis of Past Interventions to Assess Key Deployment Hindrances

    Science.gov (United States)

    2015-06-12

    collective security forces through a dedicated budget and a levy system to generate funds. At the ECOWAS level, the operationalization of the ESF is well...establishing the force headquarters. On January 30th, the former president of Burundi, Pierre Buyoya, AU high Representative for Mali and the Sahel at that time

  3. The OMERACT ultrasound task force -- Advances and priorities.

    LENUS (Irish Health Repository)

    D'Agostino, Maria-Antonietta

    2009-08-01

    This article reports the most recent work of the OMERACT Ultrasound Task Force (post OMERACT 8) and highlights of future research priorities discussed at the OMERACT 9 meeting, Kananaskis, Canada, May 2008. Results of 3 studies were presented: (1) assessing intermachine reliability; (2) applying the scoring system developed in the hand to other joints most commonly affected in rheumatoid arthritis (RA); and (3) assessing interobserver reliability on a deep target joint (shoulder). Results demonstrated good intermachine reliability between multiple examiners, and good applicability of the scoring system for the hand on other joints (including shoulder). Study conclusions were discussed and a future research agenda was generated, notably the further development of a Global OMERACT Sonography Scoring (GLOSS) system in RA, emphasizing the importance of testing feasibility and added value over standard clinical variables. Future disease areas of importance to develop include a scoring system for enthesitis and osteoarthritis.

  4. [The medical aspects of manpower recruitment for the Armed Forces].

    Science.gov (United States)

    Korsakov, L I

    1992-02-01

    The article examines the problems of draft procurement from the point of view of military medical expertise. Based upon concrete examples the authors show how the criteria of medical selection of call-up personnel depend upon the socio-demographical situation of society, principles of Defense Policy and Force planning, health status of young generation. For the improvement of the draftees' health index and the quality of medical selection it is necessary to carry out definite sanitary and prophylactic measures among personnel of pre-conscription and call-up age, as well as assign qualified medical specialists to the staff of medical boards, who are good in the questions of military medical expertise. The authors provide one of the possible variants of changes in the medical draft selection procedure.

  5. Reliability of generation at a Hanford Nuclear Energy Center (HNEC)

    International Nuclear Information System (INIS)

    Clark, R.G.; Dowis, W.J.

    1977-12-01

    A nuclear energy center characteristically would have large amounts of electric generating capacity in a relatively small geographical area. HNEC is a conceptual nuclear energy center containing 20 generating units of 1200 MW capacity each, located at Hanford, Washington. DS is an alternative concept; namely, 20 generating units of similar capacity in six clusters at sites along the Columbia and Willamette rivers in Washington and Oregon. HNEC in year 2005 could provide up to 30% of system capacity; typically utilities limit concentration of thermal plant generation to about 15% of system requirements. For this reason it is appropriate to examine the reliability of generation at a nuclear energy center to determine if it could be less than at dispersed sites because of local conditions and the close proximity of many generating units. In the report, reliability of generation HNEC is assessed by comparing it with that at Dispersed Sites (DS) throughout the Pacific Northwest. Reliability is measured in terms of two sets of risks: risk of forced outage, and risk of user power shortage

  6. 120 watt thermoelectric generator

    Science.gov (United States)

    Marling, Daryl K.

    The Manpack, a 120-W portable liquid-fueled thermoelectric generator, consists of a thermoelectric converter, multiliquid fuel combustor, forced-air cooling, and electronic microprocessor control. The Manpack can operate continuously for 8 hours (with the operation capacity extendable by the use of an auxiliary fuel connection), has an operational range of -40 C to +50 C, and an adjustable output of 24 to 32 Vdc at 120 W minimum power. The Manpack's atomizer subsystem is able to handle all types of liquid fuel including gasoline and summer diesel. Any liquid can be atomized from 0 kg/h to 1.0 kg/h over the full temperature range of the generator.

  7. Inflow Turbulence Generation Methods

    Science.gov (United States)

    Wu, Xiaohua

    2017-01-01

    Research activities on inflow turbulence generation methods have been vigorous over the past quarter century, accompanying advances in eddy-resolving computations of spatially developing turbulent flows with direct numerical simulation, large-eddy simulation (LES), and hybrid Reynolds-averaged Navier-Stokes-LES. The weak recycling method, rooted in scaling arguments on the canonical incompressible boundary layer, has been applied to supersonic boundary layer, rough surface boundary layer, and microscale urban canopy LES coupled with mesoscale numerical weather forecasting. Synthetic methods, originating from analytical approximation to homogeneous isotropic turbulence, have branched out into several robust methods, including the synthetic random Fourier method, synthetic digital filtering method, synthetic coherent eddy method, and synthetic volume forcing method. This article reviews major progress in inflow turbulence generation methods with an emphasis on fundamental ideas, key milestones, representative applications, and critical issues. Directions for future research in the field are also highlighted.

  8. Rod examination gauge

    Energy Technology Data Exchange (ETDEWEB)

    Bacvinskas, W.S.; Bayer, J.E.; Davis, W.W.; Fodor, G.; Kikta, T.J.; Matchett, R.L.; Nilsen, R.J.; Wilczynski, R.

    1991-12-31

    The present invention is directed to a semi-automatic rod examination gauge for performing a large number of exacting measurements on radioactive fuel rods. The rod examination gauge performs various measurements underwater with remote controlled machinery of high reliability. The rod examination gauge includes instruments and a closed circuit television camera for measuring fuel rod length, free hanging bow measurement, diameter measurement, oxide thickness measurement, cladding defect examination, rod ovality measurement, wear mark depth and volume measurement, as well as visual examination. A control system is provided including a programmable logic controller and a computer for providing a programmed sequence of operations for the rod examination and collection of data.

  9. Computing the flow past Vortex Generators: Comparison between RANS Simulations and Experiments

    DEFF Research Database (Denmark)

    Manolesos, M.; Sørensen, Niels N.; Troldborg, Niels

    2016-01-01

    The flow around a wind turbine airfoil equipped with Vortex Generators (VGs) is examined. Predictions from three different Reynolds Averaged Navier Stokes (RANS) solvers with two different turbulence models and two different VG modelling approaches are compared between them and with experimental ...... data. The best results are obtained with the more expensive fully resolved VG approach. The cost efficient BAY model can also provide acceptable results, if grid related numerical diffusion is minimized and only force coefficient polars are considered....

  10. Forces in strategy formation

    DEFF Research Database (Denmark)

    Steensen, Elmer Fly; Sanchez, Ron

    2008-01-01

    This chapter proposes that organizational strategy formation should be characterized theoretically as a process that is subject to several interacting forces, rather than represented by separate discrete decisionmodels or theoretic perspectives, as is commonly done in the strategic management...... literature. Based on an extensive review of relevant theory and empirical work in strategic decision-making, organizational change theory, cognitive and social psychology, and strategy processes, seven kinds of ''forces'' - rational, imposed, teleological, learning, political, heuristic, and social...... - are identified as interacting in and having significant influence on the strategy formation process. It is further argued that by applying a holistic ''forces-view'' of the significant and interacting influences on strategy formation, we can better understand the dynamics and challenges in managing the process...

  11. Generational Transitions in Platform Markets

    DEFF Research Database (Denmark)

    Kretschmer, Tobias; Claussen, Jörg

    2016-01-01

    The introduction of a new product generation forces incumbents in platform markets to rebuild their installed base of complementary products. Using three different data sets on the U.S. market for video game consoles, we show that incumbents can, to some extent, substitute for rebuilding their new...... through the reduced supply of new software. We find that both effects are moderated by the age of the new technological generation and by the technological leap between generations: backward compatibility becomes less important with increasing console age and larger technological improvement between...

  12. Electrochemical force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam F.; Rodriguez, Brian J.

    2017-01-10

    A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

  13. ForcePAD

    DEFF Research Database (Denmark)

    Lindemann, J.; Damkilde, Lars

    2009-01-01

    ForcePAD is a 2-dimensional finite element application that started as a concept application for finite element modeling. Over the course of 10 years the application has been evolved into an application that is used extensively in both an educational setting as well as a tool for design and engin......ForcePAD is a 2-dimensional finite element application that started as a concept application for finite element modeling. Over the course of 10 years the application has been evolved into an application that is used extensively in both an educational setting as well as a tool for design...

  14. Examine Your Skin

    Medline Plus

    Full Text Available ... Store In Memory Melanoma Info Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ... video. UPDATED: February 7, 2018 Melanoma Facts Melanoma Prevention Sunscreen Suggestions Examine Your Skin Newly Diagnosed? Understanding ...

  15. Wood's lamp examination

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood lamp examination To use the sharing features on this page, please enable JavaScript. A Wood lamp examination is a test that uses ultraviolet ( ...

  16. Examine Your Skin

    Medline Plus

    Full Text Available ... Suggestions Examine Your Skin Newly Diagnosed? Understanding Your Pathology Biopsy: The First Step Sentinel Node Biopsy Melanoma ... Suggestions Examine Your Skin Newly Diagnosed? Understanding Your Pathology Biopsy: The First Step Sentinel Node Biopsy Melanoma ...

  17. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    1983-10-01

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes. As appropriate, these standards will be revised periodically to accommodate comments and reflect new information or experience

  18. PULSE GENERATOR

    Science.gov (United States)

    Roeschke, C.W.

    1957-09-24

    An improvement in pulse generators is described by which there are produced pulses of a duration from about 1 to 10 microseconds with a truly flat top and extremely rapid rise and fall. The pulses are produced by triggering from a separate input or by modifying the current to operate as a free-running pulse generator. In its broad aspect, the disclosed pulse generator comprises a first tube with an anode capacitor and grid circuit which controls the firing; a second tube series connected in the cathode circuit of the first tube such that discharge of the first tube places a voltage across it as the leading edge of the desired pulse; and an integrator circuit from the plate across the grid of the second tube to control the discharge time of the second tube, determining the pulse length.

  19. Force microscopy imaging of individual protein molecules with sub-pico Newton force sensitivity.

    Science.gov (United States)

    Patil, Shivprasad; Martinez, Nicolas F; Lozano, Jose R; Garcia, Ricardo

    2007-01-01

    The capability of atomic force microscopes (AFM) to generate atomic or nanoscale resolution images of surfaces has deeply transformed the study of materials. However, high resolution imaging of biological systems has proved more difficult than obtaining atomic resolution images of crystalline surfaces. In many cases, the forces exerted by the tip on the molecules (1-10 nN) either displace them laterally or break the noncovalent bonds that hold the biomolecules together. Here, we apply a force microscope concept based on the simultaneous excitation of the first two flexural modes of the cantilever. The coupling of the modes generated by the tip-molecule forces enables imaging under the application of forces ( approximately 35 pN) which are smaller than those needed to break noncovalent bonds. With this instrument we have resolved the intramolecular structure of antibodies in monomer and pentameric forms. Furthermore, the instrument has a force sensitivity of 0.2 pN which enables the identification of compositional changes along the protein fragments. Copyright (c) 2007 John Wiley & Sons, Ltd.

  20. Force Structure: Better Information Needed to Support Air Force A-10 and Other Future Divestment Decisions

    Science.gov (United States)

    2016-08-01

    timeframes and identify and examine new concepts and capabilities. • Future F-35 versions are expected to improve on CAS capability from the “basic...in Vietnam Rep. Otis Pike chaired a subcommittee for 7 days to investigate Vietnam CAS deficiencies. 1966 Johnson- McConnell Agreement Air Force...First F-16 delivered to Air Force 1982 The Army developed concept on AirLand battle U.S. Army Training and Doctrine Command developed this concept to

  1. Status of Forces and Criminal Jurisdiction

    NARCIS (Netherlands)

    Joop Voetelink

    2013-01-01

    This article examines the legal status of armed forces present in friendly foreign territory with a special focus on criminal jurisdiction. Traditionally, this issue has been considered from the perspective of public international law in which immunities play an important role. However, this

  2. Influence of the distance in a roundhouse kick's execution time and impact force in Taekwondo.

    Science.gov (United States)

    Falco, Coral; Alvarez, Octavio; Castillo, Isabel; Estevan, Isaac; Martos, Julio; Mugarra, Fernando; Iradi, Antonio

    2009-02-09

    Taekwondo, originally a Korean martial art, is well known for its kicks. One of the most frequently used kicks in competition is Bandal Chagui or roundhouse kick. Excellence in Taekwondo relies on the ability to make contact with the opponent's trunk or face with enough force in as little time as possible, while at the same time avoiding being hit. Thus, the distance between contestants is an important variable to be taken into consideration. Thirty-one Taekwondo athletes in two different groups (expert and novice, according to experience in competition) took part in this study. The purpose of this study was to examine both impact force and execution time in a Bandal Chagui or roundhouse kick, and to explore the effect of execution distance in these two variables. A new model was developed in order to measure the force exerted by the body on a load. A force platform and a contact platform were used to measure these variables. The results showed that there are no significant differences in terms of impact force in relation to execution distance in expert competitors. Significant and positive correlations between body mass and impact force (p<.01) seem to mean that novice competitors use their body mass to generate high impact forces. Significant differences were found in competitive experience and execution time for the three different distances of kicking considered in the study. Standing at a certain further distance from the opponent should be an advantage for competitors who are used to kick from a further distance in their training.

  3. User's Manual for SAG-2 SHARC/SAMM Atmosphere Generator

    National Research Council Canada - National Science Library

    Shroll, Robert

    2003-01-01

    The SHARC Atmosphere Generator (SAG) is a stand-alone, interactive program that utilizes a combination of empirical models to generate atmospheric profiles for Air Force IR radiation codes that account for systematic variability...

  4. TMI-2 core examination

    International Nuclear Information System (INIS)

    Hobbins, R.R.; MacDonald, P.E.; Owen, D.E.

    1983-01-01

    The examination of the damaged core at the Three Mile Island Unit 2 (TMI-2) reactor is structured to address the following safety issues: fission product release, transport, and deposition; core coolability; containment integrity; and recriticality during severe accidents; as well as zircaloy cladding ballooning and oxidation during so-called design basis accidents. The numbers of TMI-2 components or samples to be examined, the priority of each examination, the safety issue addressed by each examination, the principal examination techniques to be employed, and the data to be obtained and the principal uses of the data are discussed in this paper

  5. Aerodynamic forces and flow structures of the leading edge vortex on a flapping wing considering ground effect

    International Nuclear Information System (INIS)

    Truong, Tien Van; Yoon, Kwang Joon; Byun, Doyoung; Kim, Min Jun; Park, Hoon Cheol

    2013-01-01

    The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff

  6. Aerodynamic forces and flow structures of the leading edge vortex on a flapping wing considering ground effect.

    Science.gov (United States)

    Van Truong, Tien; Byun, Doyoung; Kim, Min Jun; Yoon, Kwang Joon; Park, Hoon Cheol

    2013-09-01

    The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff.

  7. Operator licensing examiner standards

    International Nuclear Information System (INIS)

    1994-06-01

    The Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining licensees and applicants for reactor operator and senior reactor operator licenses at power reactor facilities pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR 55). The Examiner Standards are intended to assist NRC examiners and facility licensees to better understand the initial and requalification examination processes and to ensure the equitable and consistent administration of examinations to all applicants. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator licensing policy changes. Revision 7 was published in January 1993 and became effective in August 1993. Supplement 1 is being issued primarily to implement administrative changes to the requalification examination program resulting from the amendment to 10 CFR 55 that eliminated the requirement for every licensed operator to pass an NRC-conducted requalification examination as a condition for license renewal. The supplement does not substantially alter either the initial or requalification examination processes and will become effective 30 days after its publication is noticed in the Federal Register. The corporate notification letters issued after the effective date will provide facility licensees with at least 90 days notice that the examinations will be administered in accordance with the revised procedures

  8. New gravitational forces from quantum theory

    International Nuclear Information System (INIS)

    Nieto, M.M.; Goldman, T.; Hughes, R.J.

    1988-01-01

    When a classical theory is quantized, new physical effects result. The prototypical example is the Lamb Shift of quantum electrodynamics. Even though this phenomenon could be parametrized by the ''Uehling Potential,'' it was always realized that it was a quantum aspect of electromagnetism, not a ''new force'' of nature. So, too, with theories of quantum gravity. Generically they predict that there will be spin-1 (graviphoton) and spin-0 (graviscalar) partners of the spin-2 graviton. At some level, these partners will generate new effects. Among them are (1) non-Newtonian gravitational forces and (2) substance dependance (violation of the Principle of Equivalence). We discuss these ideas in the context of recent experiments. (Experiments usually test only one of the above effects, which could be distinct.) We contrast these ideas with the alternative point of view, that there actually may be a ''fifth force'' of nature. 20 refs

  9. due to Capillary Forces

    Directory of Open Access Journals (Sweden)

    Hassen M. Ouakad

    2009-01-01

    Full Text Available We present modeling and analysis for the static behavior and collapse instabilities of doubly-clamped and cantilever microbeams subjected to capillary forces. These forces can be as a result of a volume of liquid trapped underneath the microbeam during the rinsing and drying process in fabrication. The model considers the microbeam as a continuous medium, the capillary force as a nonlinear function of displacement, and accounts for the mid-plane stretching and geometric nonlinearities. The capillary force is assumed to be distributed over a specific length underneath the microbeam. The Galerkin procedure is used to derive a reduced-order model consisting of a set of nonlinear algebraic and differential equations that describe the microbeams static and dynamic behaviors. We study the collapse instability, which brings the microbeam from its unstuck configuration to touch the substrate and gets stuck in the so-called pinned configuration. We calculate the pull-in length that distinguishes the free from the pinned configurations as a function of the beam thickness and gap width for both microbeams. Comparisons are made with analytical results reported in the literature based on the Ritz method for linear and nonlinear beam models. The instability problem, which brings the microbeam from a pinned to adhered configuration is also investigated. For this case, we use a shooting technique to solve the boundary-value problem governing the deflection of the microbeams. The critical microbeam length for this second instability is also calculated.

  10. The fifth force

    International Nuclear Information System (INIS)

    Fischbach, E.; Sudarsky, D.; Szafer, A.; Talmadge, C.; Aronson, S.H.

    1986-01-01

    We present a phenomenological description of the ''fifth force'' which focuses on the implications of the existing data from satellite and geophysical measurements of gravity, the Eoetvoes experiment, decays into hyperphotons, and the energy-dependence of the K 0 - anti K 0 parameters

  11. Magnetic Force Microscopy

    NARCIS (Netherlands)

    Abelmann, Leon

    Principle of MFM In magnetic force microscopy (MFM), the magnetic stray field above a very flat specimen, or sample, is detected by placing a small magnetic element, the tip, mounted on a cantilever spring very close to the surface of the sample (Figure 1). Typical dimensions are a cantilever length

  12. Separation problems and forcing

    Czech Academy of Sciences Publication Activity Database

    Zapletal, Jindřich

    2013-01-01

    Roč. 13, č. 1 (2013), s. 1350002 ISSN 0219-0613 R&D Projects: GA AV ČR IAA100190902 Institutional research plan: CEZ:AV0Z10190503 Keywords : separation * set of uniqueness * forcing Subject RIV: BA - General Mathematics Impact factor: 0.364, year: 2012 http://www.worldscientific.com/doi/abs/10.1142/S0219061313500025

  13. Allegiance: Egypt Security Forces

    Science.gov (United States)

    2013-12-01

    expected after the uprising of 2011 never truly materialized; the Interior Ministry instituted various cosmetic changes, but its basic construct and...military forces located there. The masked men appeared to be shooting and the army responded, shooting back.284 Whatever the stories

  14. Activation force splines

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol; Erleben, Kenny

    We present a method for simulating the active contraction of deformable models, usable for interactive animation of soft deformable objects. We present a novel physical principle as the governing equation for the coupling between the low dimensional 1D activation force model and the higher...

  15. Generation Next

    Science.gov (United States)

    Hawkins, B. Denise

    2010-01-01

    There is a shortage of accounting professors with Ph.D.s who can prepare the next generation. To help reverse the faculty deficit, the American Institute of Certified Public Accountants (CPAs) has created the new Accounting Doctoral Scholars program by pooling more than $17 million and soliciting commitments from more than 70 of the nation's…

  16. Generative Contexts

    Science.gov (United States)

    Lyles, Dan Allen

    Educational research has identified how science, technology, engineering, and mathematics (STEM) practice and education have underperforming metrics in racial and gender diversity, despite decades of intervention. These disparities are part of the construction of a culture of science that is alienating to these populations. Recent studies in a social science framework described as "Generative Justice" have suggested that the context of social and scientific practice might be modified to bring about more just and equitable relations among the disenfranchised by circulating the value they and their non-human allies create back to them in unalienated forms. What is not known are the underlying principles of social and material space that makes a system more or less generative. I employ an autoethnographic method at four sites: a high school science class; a farm committed to "Black and Brown liberation"; a summer program geared towards youth environmental mapping; and a summer workshop for Harlem middle school students. My findings suggest that by identifying instances where material affinity, participatory voice, and creative solidarity are mutually reinforcing, it is possible to create educational contexts that generate unalienated value, and circulate it back to the producers themselves. This cycle of generation may help explain how to create systems of justice that strengthen and grow themselves through successive iterations. The problem of lack of diversity in STEM may be addressed not merely by recruiting the best and the brightest from underrepresented populations, but by changing the context of STEM education to provide tools for its own systematic restructuring.

  17. Fifth force, sixth force and all that

    International Nuclear Information System (INIS)

    Recami, E.; Tonin Zanchin, V.

    1988-01-01

    In the recent literature, a few claims appeared about possible deviations from the ordinary gravitational laws (both at the terrestrial and at the galactic level). The experimental evidence does not seem to be conclusive; nor its is clear if new forces are showing up, or if we have to accept actual deviations from Newton or Einstein gravitation (in the latter case, the validity of the very Equivalence Principle might be on the stage). In such a situation, the attempts by various authors at explaining the ''new effects'' just on the basis of the ordinary theory of General Relativity (for instance, in terms of quantum gravity) can be regarded as logically instance, in terms of quantum gravity) can be regarded as logically questionable. In this pedagogically oriented paper, the problem is approached within the classical realm, by exploring whether the possible new effects can be accounted for through minimal modifications of the standard formulatiaon of General Relativity: in particular, through exploitation and extension of the role of the cosmological constant

  18. Biodegradable Piezoelectric Force Sensor.

    Science.gov (United States)

    Curry, Eli J; Ke, Kai; Chorsi, Meysam T; Wrobel, Kinga S; Miller, Albert N; Patel, Avi; Kim, Insoo; Feng, Jianlin; Yue, Lixia; Wu, Qian; Kuo, Chia-Ling; Lo, Kevin W-H; Laurencin, Cato T; Ilies, Horea; Purohit, Prashant K; Nguyen, Thanh D

    2018-01-30

    Measuring vital physiological pressures is important for monitoring health status, preventing the buildup of dangerous internal forces in impaired organs, and enabling novel approaches of using mechanical stimulation for tissue regeneration. Pressure sensors are often required to be implanted and directly integrated with native soft biological systems. Therefore, the devices should be flexible and at the same time biodegradable to avoid invasive removal surgery that can damage directly interfaced tissues. Despite recent achievements in degradable electronic devices, there is still a tremendous need to develop a force sensor which only relies on safe medical materials and requires no complex fabrication process to provide accurate information on important biophysiological forces. Here, we present a strategy for material processing, electromechanical analysis, device fabrication, and assessment of a piezoelectric Poly-l-lactide (PLLA) polymer to create a biodegradable, biocompatible piezoelectric force sensor, which only employs medical materials used commonly in Food and Drug Administration-approved implants, for the monitoring of biological forces. We show the sensor can precisely measure pressures in a wide range of 0-18 kPa and sustain a reliable performance for a period of 4 d in an aqueous environment. We also demonstrate this PLLA piezoelectric sensor can be implanted inside the abdominal cavity of a mouse to monitor the pressure of diaphragmatic contraction. This piezoelectric sensor offers an appealing alternative to present biodegradable electronic devices for the monitoring of intraorgan pressures. The sensor can be integrated with tissues and organs, forming self-sensing bionic systems to enable many exciting applications in regenerative medicine, drug delivery, and medical devices.

  19. Molecular force sensors to measure stress in cells

    International Nuclear Information System (INIS)

    Prabhune, Meenakshi; Rehfeldt, Florian; Schmidt, Christoph F

    2017-01-01

    Molecularly generated forces are essential for most activities of biological cells, but also for the maintenance of steady state or homeostasis. To quantitatively understand cellular dynamics in migration, division, or mechanically guided differentiation, it will be important to exactly measure stress fields within the cell and the extracellular matrix. Traction force microscopy and related techniques have been established to determine the stress transmitted from adherent cells to their substrates. However, different approaches are needed to directly assess the stress generated inside the cell. This has recently led to the development of novel molecular force sensors. In this topical review, we briefly mention methods used to measure cell-external forces, and then summarize and explain different designs for the measurement of cell-internal forces with their respective advantages and disadvantages. (topical review)

  20. Non-equilibrium Casimir force between vibrating plates.

    Directory of Open Access Journals (Sweden)

    Andreas Hanke

    Full Text Available We study the fluctuation-induced, time-dependent force between two plates confining a correlated fluid which is driven out of equilibrium mechanically by harmonic vibrations of one of the plates. For a purely relaxational dynamics of the fluid we calculate the fluctuation-induced force generated by the vibrating plate on the plate at rest. The time-dependence of this force is characterized by a positive lag time with respect to the driving. We obtain two distinctive contributions to the force, one generated by diffusion of stress in the fluid and another related to resonant dissipation in the cavity. The relation to the dynamic Casimir effect of the electromagnetic field and possible experiments to measure the time-dependent Casimir force are discussed.