Science.gov

Sample records for internal forces

  1. On the work of internal forces

    NASA Astrophysics Data System (ADS)

    Güémez, J.; Fiolhais, M.; Brito, L.

    2015-07-01

    We discuss the role of the internal forces and how their work changes the energy of a system. We illustrate the contribution of the internal work to the variation of the system’s energy, using a pure mechanical example, a thermodynamical system and an example from electromagnetism. We emphasize that internal energy variations related to the work of the internal forces should be pinpointed in the classroom and placed on the same footing as other internal energy variations such as those caused by temperature changes or by chemical reactions.

  2. Estimating internal variability under changing external forcing

    NASA Astrophysics Data System (ADS)

    Olonscheck, Dirk; Notz, Dirk

    2016-04-01

    A robust estimate of internal variability is crucial for a wide range of climate-study applications, be it model evaluation, predictions, projections, or attribution studies. While internal variability can readily be estimated from standard pre-industrial control simulations, under changing forcing ensemble simulations are required to estimate internal variability. However, such estimate is only possible for those models that provide several ensemble simulations. To overcome this limitation, we here show how internal variability for a changing forcing can be estimated for all models from their pre-industrial control simulation provided that at least some models of the ensemble provide several simulations. To obtain the total internal variability of forced simulations largely independent of the ensemble size of individual models, we correct for the small ensemble sizes the models provide. This allows us to show that across the CMIP5 model ensemble, the time-period-averaged internal variability of global-mean surface temperature remains unchanged for historical and future simulations even for large CO2 forcing, while the time-period-averaged internal variability of most sea-ice-related variables decreases proportionally to their mean state. This emergent constraint for sea ice allows one to roughly estimate the internal variability simply based on the mean state and illuminates how the changing external forcing alters the system's internal variability. Our findings show that the internal variability estimate from each pre-industrial control simulation can be used for the present and translated to the future and thus limits the need of large ensembles for internal variability studies. Applying our approach to model evaluation of sea-ice simulations, we confirm that the plausibility of simulations differs widely and that internal variability can explain most of the model's deviation from the observed trend, but often not the model's deviation from the mean state. The

  3. International Task Force on Volunteer Cleft Missions.

    PubMed

    Yeow, Vincent K L; Lee, Seng-Teik T; Lambrecht, Thomas J; Barnett, John; Gorney, Mark; Hardjowasito, Widanto; Lemperle, Gottfried; McComb, Harold; Natsume, Nagato; Stranc, Mirek; Wilson, Libby

    2002-01-01

    The International Task Force on Volunteer Cleft Missions was set up to provide a report to be presented at the Eighth International Congress of Cleft Palate and Associated Craniofacial Anomalies on September 12, 1997, in Singapore. The aim of the report was to provide data from a wide range of different international teams performing volunteer cleft missions and, thereafter, based on the collected data, to identify common goals and aims of such missions. Thirteen different groups actively participating in volunteer cleft missions worldwide were selected from the International Confederation of Plastic and Reconstructive Surgery's list of teams actively participating in volunteer cleft missions. Because of the time frame within which the committee had to work, three groups that did not respond by the stipulated deadline were omitted from the committee. The represented members and their respective institutions have undertaken more than 50 volunteer cleft missions to underdeveloped nations worldwide within the last 3 years. They have visited over 20 different countries, treating more than 3,500 patients worldwide. Based on the data collected and by consensus, the committee outlined recommendations for future volunteer cleft missions based on 1) mission objectives, 2) organization, 3) personal health and liability, 4) funding, 5) trainees in volunteer cleft missions, and 6) public relations. The task force believed that all volunteer cleft missions should have well-defined objectives, preferably with long-term plans. The task force also decided that it was impossible to achieve a successful mission without good organization and close coordination. All efforts should be made, and care taken, to ensure that there is minimal morbidity and no mortality. Finally, as ambassadors of goodwill and humanitarian aid, the participants must make every effort to understand and respect local customs and protocol. The main aims are to provide top-quality surgical service, train local

  4. Female labor force participation: an international perspective.

    PubMed

    Psacharopoulos, G; Tzannatos, Z

    1989-07-01

    This article gives an international perspective in regard to female participation in the labor force. In most countries women contribute less than men toward the value of recorded production. Social environment, statistical inconsistencies and methods of recording labor all contribute to this inequity. In Britain for instance, women caring for the household duties are in some studies considered to be part of the labor force and in other studies they are not. Further, internationally, women often find themselves in casual, temporary, or seasonal work that goes unrecorded. Defining what "labor force participation" constitutes is a key starting point to any survey. At what age is one considered employable? What constitutes a person "actively seeking" employment? Economists often try to explain labor force participation rate by age, sex, race and income groups and use this information to cite trends. The income-leisure model theorizes that choice of work or non-work by women is based primarily upon wages for work vs. wages for non-work. This theory sees non-labor income exerting a negative influence. Empirical evidence, however, suggests that women will choose work if wages are good regardless of any non-work benefits. Because most men are permanently in the labor force, estimates of labor reserves and projections of supply focus mostly on women. International generalizations are often misleading since trends vary widely among countries. During the last 20 years the global female participation rate has remained almost constant, but this is misleading. The percentage of working women in industrial countries increased 10%; developing countries showed a decrease of 7%. Female rates are often tied closely to shifts in the overall economy, (e.g., a transition from an agricultural to an industrial economy often sees a drop in female labor because subsistence jobs are lost). Of course the ability of women to bear children and the social expectations regarding child care often

  5. Industrial Energy Conservation, Forced Internal Recirculation Burner

    SciTech Connect

    Joseph Rabovitser

    2003-06-19

    The overall objective of this research project is to develop and evaluate an industrial low NOx burner for existing and new gas-fired combustion systems for intermediate temperature (1400 degree to 2000 degree F) industrial heating devices such as watertube boilers and process fluid heaters. A multi-phase effort is being pursued with decision points to determine advisability of continuance. The current contract over Phases II and III of this work. The objectives of each phase are as follows. Phase II - to design, fabricate, and evaluate prototype burners based on the Forced Internal Recirculation (FIR) concept. Phase III - to evaluate the performance of an FIR burner under actual operating conditions in a full-scale field test and establish the performance necessary for subsequent commercialization

  6. 47 CFR 2.100 - International regulations in force.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false International regulations in force. 2.100 Section 2.100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO....100 International regulations in force. The ITU Radio Regulations, Edition of 2004, have...

  7. 47 CFR 2.100 - International regulations in force.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false International regulations in force. 2.100 Section 2.100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO....100 International regulations in force. The ITU Radio Regulations, edition of 2004, have...

  8. 47 CFR 2.100 - International regulations in force.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false International regulations in force. 2.100 Section 2.100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO....100 International regulations in force. The ITU Radio Regulations, Edition of 2004, have...

  9. 47 CFR 2.100 - International regulations in force.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false International regulations in force. 2.100 Section 2.100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO....100 International regulations in force. The ITU Radio Regulations, Edition of 2004, have...

  10. 47 CFR 2.100 - International regulations in force.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false International regulations in force. 2.100 Section 2.100 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO....100 International regulations in force. The ITU Radio Regulations, Edition of 2004, have...

  11. Joining Forces: The Case of Alliant International University

    ERIC Educational Resources Information Center

    Leslie, Heather

    2013-01-01

    Mergers and acquisitions are a prevalent force in higher education as more colleges and universities are joining forces to expand resources, enhance missions, or prevent closures. This study examines the merger of Alliant University (formerly California School of Professional Psychology) with United States International University to create what…

  12. Locomotive and reptation motion induced by internal force and friction.

    PubMed

    Sakaguchi, Hidetsugu; Ishihara, Taisuke

    2011-06-01

    We propose a simple mechanical model of locomotion induced by internal force and friction. We first construct a system of two elements as an analog of the bipedal motion. The internal force does not induce a directional motion by itself because of the action-reaction law, but a directional motion becomes possible by the control of the frictional force. The efficiency of these model systems is studied using an analogy to the heat engine. As a modified version of the two-element model, we construct a model that exhibits a bipedal motion similar to kinesin's motion of molecular motor. Next, we propose a linear chain model and a ladder model as an extension of the original two-element model. We find a transition from a straight to a snake-like motion in a ladder model by changing the strength of the internal force. PMID:21797399

  13. Locomotive and reptation motion induced by internal force and friction

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Hidetsugu; Ishihara, Taisuke

    2011-06-01

    We propose a simple mechanical model of locomotion induced by internal force and friction. We first construct a system of two elements as an analog of the bipedal motion. The internal force does not induce a directional motion by itself because of the action-reaction law, but a directional motion becomes possible by the control of the frictional force. The efficiency of these model systems is studied using an analogy to the heat engine. As a modified version of the two-element model, we construct a model that exhibits a bipedal motion similar to kinesin’s motion of molecular motor. Next, we propose a linear chain model and a ladder model as an extension of the original two-element model. We find a transition from a straight to a snake-like motion in a ladder model by changing the strength of the internal force.

  14. Internal combustion engine with balancing forces

    SciTech Connect

    Fisher, M.A.

    1990-07-10

    This patent describes an internal combustion engine of the opposed cylinder type. It comprises: a crankshaft and at least one set of pistons movably connected thereto. Each piston of the one set is reciprocally mounted within a separate corresponding cylinder and rotatably drive the crankshaft during a power stroke thereof, the one set of pistons including at least a first piston and cylinder assembly mounted on one side of the crankshaft and at least a second and a third piston and cylinder assembly mounted on the other side of the crankshaft in directly opposed relation to the first piston and cylinder assembly, each of the cylinders of the second and third piston and cylinder assemblies comprising one half the displacement volume of the cylinder of the first piston and cylinder assembly, whereby vibration of the engine is substantially reduced at all running speeds.

  15. The Internal Forces of Creativity: When Hearts Start to Flutter.

    ERIC Educational Resources Information Center

    Gnezda-Smith, Nicole

    1994-01-01

    Four artistic people of various ages were interviewed concerning their conscious and unconscious thought during creative activity, emotions which precipitated creative activity and intermingled with cognition, and intrinsic motivators and rewards. The interviews supported research regarding the internal forces of creativity. (Author/JDD)

  16. Forcing, feedback and internal variability in global temperature trends.

    PubMed

    Marotzke, Jochem; Forster, Piers M

    2015-01-29

    Most present-generation climate models simulate an increase in global-mean surface temperature (GMST) since 1998, whereas observations suggest a warming hiatus. It is unclear to what extent this mismatch is caused by incorrect model forcing, by incorrect model response to forcing or by random factors. Here we analyse simulations and observations of GMST from 1900 to 2012, and show that the distribution of simulated 15-year trends shows no systematic bias against the observations. Using a multiple regression approach that is physically motivated by surface energy balance, we isolate the impact of radiative forcing, climate feedback and ocean heat uptake on GMST--with the regression residual interpreted as internal variability--and assess all possible 15- and 62-year trends. The differences between simulated and observed trends are dominated by random internal variability over the shorter timescale and by variations in the radiative forcings used to drive models over the longer timescale. For either trend length, spread in simulated climate feedback leaves no traceable imprint on GMST trends or, consequently, on the difference between simulations and observations. The claim that climate models systematically overestimate the response to radiative forcing from increasing greenhouse gas concentrations therefore seems to be unfounded. PMID:25631444

  17. Internal flows and force matrices in axial flow inducers

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Abhijit

    1994-01-01

    Axial flow inducers such as those used in high speed rocket engine turbopumps are subject to complex internal flows and fluid-induced lateral and rotordynamic forces. An investigation of these internal flows was conducted using boundary layer flow visualization on the blades, hub and housing of unshrouded and shrouded inducers. Results showed that the blade boundary layer flows have strong radial components at off-design conditions and remain attached to the blade surface at all flow coefficients tested. The origin of upstream swirling backflow was found to be at the discharge plane of the inducer. In addition, flow reversal was observed at the suction side blade tip near the leading edge in a shrouded inducer. Re-entry of the hub boundary layer flow, a downstream backflow, into the blade passage area was observed at flow coefficients below design. For unshrouded inducers the radially outward flow near the blade tip mixed with the leakage flow to form the upstream backflow. The lateral and rotordynamic forces acting on an inducer due to an imposed whirl motion was also investigated at various flow coefficients. It was found that the rotordynamic force data at various whirl frequency ratios does not allow a normal quadratic fit; consequently the conventional inertial, stiffness and damping coefficients cannot be obtained and a definite whirl ratio describing the instability region does not result. Application of an actuator disk theory proved to be inaccurate in estimating the rotordynamic tangential force in a non-whirling inducer. The effect of upstream and downstream flow distortions on the rotordynamic and lateral forces on an inducer were studied. It was found that at flow coefficients below design, large lateral forces occurred in the presence of a downstream asymmetry. Results of inlet distortion experiments show that a strong inlet shear causes a significant increase in the lateral force. Cavitation was found to have important consequences for fluid

  18. Atomic force microscopy to detect internal live processes in insects

    NASA Astrophysics Data System (ADS)

    Dokukin, M. E.; Guz, N. V.; Vasilyev, S.; Sokolov, I.

    2010-01-01

    Here we report on the use of atomic force microscopy (AFM) to study surface oscillations coming from internal live processes of insects. With a specially designed AFM stage to keep an insect motion partially restricted, the AFM can record internal oscillations on different parts of the insect. We demonstrate the method for a fly, mosquito, and lady beetle. We show that AFM can provide information about the spectral behavior that has not been studied so far, 10-600 Hz range, detecting amplitudes down to subnanometer level.

  19. Permeability of continental crust influenced by internal and external forcing

    USGS Publications Warehouse

    Rojstaczer, S.A.; Ingebritsen, S.E.; Hayba, D.O.

    2008-01-01

    The permeability of continental crust is so highly variable that it is often considered to defy systematic characterization. However, despite this variability, some order has been gleaned from globally compiled data. What accounts for the apparent coherence of mean permeability in the continental crust (and permeability-depth relations) on a very large scale? Here we argue that large-scale crustal permeability adjusts to accommodate rates of internal and external forcing. In the deeper crust, internal forcing - fluxes induced by metamorphism, magmatism, and mantle degassing - is dominant, whereas in the shallow crust, external forcing - the vigor of the hydrologic cycle - is a primary control. Crustal petrologists have long recognized the likelihood of a causal relation between fluid flux and permeability in the deep, ductile crust, where fluid pressures are typically near-lithostatic. It is less obvious that such a relation should pertain in the relatively cool, brittle upper crust, where near-hydrostatic fluid pressures are the norm. We use first-order calculations and numerical modeling to explore the hypothesis that upper-crustal permeability is influenced by the magnitude of external fluid sources, much as lower-crustal permeability is influenced by the magnitude of internal fluid sources. We compare model-generated permeability structures with various observations of crustal permeability. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

  20. Foot Forces during Treadmill Exercise on the International Space Station

    NASA Technical Reports Server (NTRS)

    Cavanagh, Peter R.; Rice, Andrea J.; Maender, Christian C.; Gopalakrishnan, Raghavan; Genc, Kerim O.; Kuklis, Matthew

    2006-01-01

    Exercise has been the primary countermeasure to combat musculoskeletal changes during the approximately 6 month missions to the International Space Station (ISS). However, these countermeasures have not been successful in preventing loss of bone mineral density in the spine and hip of astronauts. We examined lower extremity loading during typical bouts of on-orbit exercise performed by 4 ISS crew members on the ISS treadmill (TVIS) and during locomotor activities on earth (1g). In-shoe forces were monitored at 128Hz using force-measuring insoles placed inside the shoes of the exercising crewmember, stored temporarily on Flash cards, and down-linked via satellite for analysis. Custom software extracted peak forces from up to 30 minutes of locomotor activity. All on-orbit loading conditions for walking and running resulted in peak forces and impact loading rates that were significantly less than those measured in 1g. Typical single leg loads on-orbit in walking and running were 0.860 plus or minus 0.04 body weights (BW) and 1.339 plus or minus 0.07 BW compared to 1.2 plus or minus 0.036 BW and 2.36 plus or minus 0.07 BW in 1g BW respectively. These results indicate that typical exercise on the ISS treadmill does not generate 1g-like loading conditions. This may be partly responsible for the loss of bone mineral density that has been observed in these and other crew members. Since on-orbit treadmill exercise requires a restraining load to return the crew member to the treadmill surface, more studies are required to enable comfortable full body weight loading to be applied.

  1. Stopping intense beams of internally cold molecules via centrifugal forces

    NASA Astrophysics Data System (ADS)

    Wu, Xing; Gantner, Thomas; Zeppenfeld, Martin; Chervenkov, Sotir; Rempe, Gerhard

    2016-05-01

    Cryogenic buffer-gas cooling produces intense beams of internally cold molecules. It offers a versatile source for studying collision dynamics and reaction pathways in the cold regime, and could open new avenues for controlled chemistry, precision spectroscopy, and exploration of fundamental physics. However, an efficient deceleration of these beams still presents a challenge. Here, we demonstrate that intense and continuous beams of electrically guided molecules produced by a cryogenic buffer-gas cell can be brought to a halt by the centrifugal force in a rotating frame. Various molecules (e.g. CH3F and CF3CCH) are decelerated to below 20m /s at a corresponding output intensity of ~ 6 ×109mm-2 .s-1 . In addition, our RF-resonant depletion detection shows that up to 90 % rotational-state purity can be achieved in the so-produced slow molecular beams.

  2. International Reference Ionosphere (IRI): Task Force Activity 2000

    NASA Technical Reports Server (NTRS)

    Bilitza, D.

    2000-01-01

    The annual IRI Task Force Activity was held at the Abdus Salam International Center for Theoretical Physics in Trieste, Italy from July 10 to July 14. The participants included J. Adeniyi (University of Ilorin, Nigeria), D. Bilitza (NSSDC/RITSS, USA), D. Buresova (Institute of Atmospheric Physics, Czech Republic), B. Forte (ICTP, Italy), R. Leitinger (University of Graz, Austria), B. Nava (ICTP, Italy), M. Mosert (University National Tucuman, Argentina), S. Pulinets (IZMIRAN, Russia), S. Radicella (ICTP, Italy), and B. Reinisch (University of Mass. Lowell, USA). The main topic of this Task Force Activity was the modeling of the topside ionosphere and the development of strategies for modeling of ionospheric variability. Each day during the workshop week the team debated a specific modeling problem in the morning during informal presentations and round table discussions of all participants. Ways of resolving the specific modeling problem were devised and tested in the afternoon in front of the computers of the ICTP Aeronomy and Radiopropagation Laboratory using ICTP s computer networks and internet access.

  3. Evaluation of Bite Force After Open Reduction and Internal Fixation Using Microplates

    PubMed Central

    Kumar, S Tharani; Saraf, Saurabh; Devi, S Prasanna

    2013-01-01

    The primary aim of this study is to determine maximum bite force in molar and incisor regions of healthy individuals, to evaluate the bite force after open reduction and internal fixation of mandibular fractures using micro plates, for a period of up to 6 weeks and to determine the rate of recovery of maximum bite force in an Indian population. PMID:24910656

  4. On the calculation of internal forces in mechanically stressed polyatomic molecules

    SciTech Connect

    Avdoshenko, Stanislav M.; Konda, Sai Sriharsha M.; Makarov, Dmitrii E.

    2014-10-07

    We discuss how to define and to compute internal forces in a molecule subjected to mechanical stress. Because of the inherently many-body character of intramolecular interactions, internal forces cannot be uniquely defined without specifying a set of internal coordinates used to describe the molecular structure. When such a set is comprised of 3N − 6 interactomic distances (N being the number of atoms) and includes the bond lengths of interest, we show that the associated forces, while satisfying the equation F = ∂V/∂R (where R is the bond length, F is the internal force in this bond, and V is the potential energy of the molecule), can be determined from the molecular geometry alone. We illustrate these ideas using several toy models ranging from small molecules to a graphene sheet and show that the magnitude of the internal force in a bond is not necessarily a good predictor of its strength in response to mechanical loading. At the same time, analysis of internal forces reveals interesting phenomena such as the force multiplication effect, where weak external forces may, e.g., be used to break strong bonds, and offers insight into the catch-bond phenomenon where chemical reactivity is suppressed through application of a force.

  5. Reflections on a Seminal Force in International Accounting

    ERIC Educational Resources Information Center

    Cascini, Karen T.

    2007-01-01

    Accounting is a manifestation of several important environmental factors within a country, including economic, educational and political, and, as such, is evolutionary in accordance with those changing social structures. Because of the major impact that international accounting has had on countries' internal accounting systems, it is important to…

  6. Internal waves generated by unsteady impulsive forcing - numerical simulations

    NASA Astrophysics Data System (ADS)

    Paoletti, Matthew; Shipley, Kara; Brandt, Alan

    2014-11-01

    Numerical simulations of the generation of internal waves by an unsteady impulse are presented. While extensive work has examined the generation of internal waves by steady flow, such as winds over mountains, or periodic flow, an example being tidal flow over bathymetry, internal waves can also be generated by transient events like those produced by local instabilities. The studies presented here focus on the generation of internal waves by the release of a patch of miscible fluid of constant density into a stably stratified water column. The fluid descends owing to its initial momentum, spreads in the lateral direction, and vertically displaces the isopycnals, leading to the generation of internal waves. The transfer of energy from the impulse to the internal wave field is characterized by the energy flux of the radiated internal waves. While the impulse is initially axisymmetric, the effects of the three-dimensional nature of the turbulent evolution are examined by comparing the results of two-dimensional and three-dimensional numerical simulations. Supported by the Office of Navel Research.

  7. Labour Force Participation Rates of Older Persons: An International Comparison.

    ERIC Educational Resources Information Center

    Clark, Robert L.; Anker, Richard

    1990-01-01

    Using data from 151 countries, labor force participation of older men and women was analyzed and related to economic, demographic, and policy variables. Reduced participation rates are related to increased income levels, structural changes, social security programs, and, for men, the ratio of older persons to persons of standard working age. (SK)

  8. INTERNAL LABOR MARKETS, TECHNOLOGICAL CHANGE, AND LABOR FORCE ADJUSTMENT.

    ERIC Educational Resources Information Center

    DOERINGER, PETER B.; PIORE, MICHAEL J.

    DIFFERENCES BETWEEN LABOR FORCE SKILLS AND THE REQUIREMENTS OF BLUE COLLAR JOBS ARE RECONCILED BY MEANS OVER WHICH THE EMPLOYER, ALONE OR WITH A LABOR ORGANIZATION, EXERCISES CONTROL. THE ADJUSTMENT MODEL PRESENTED IN THIS STUDY RECOGNIZES AN INPLANT LABOR MARKET CONNECTED TO THE EXTERNAL MARKET AT A LIMITED NUMBER OF POINTS. CERTAIN…

  9. Internal Electron Tunneling Enabled Ultrasensitive Position/Force Peapod Sensors.

    PubMed

    Tao, Xinyong; Fan, Zheng; Nelson, Bradley J; Dharuman, Gautham; Zhang, Wenkui; Dong, Lixin; Li, Xiaodong

    2015-11-11

    The electron quantum tunneling effect guarantees the ultrahigh spatial resolution of the scanning tunneling microscope (STM), but there have been no other significant applications of this effect after the invention of STM. Here we report the implementation of electron-tunneling-based high sensitivity transducers using a peapod B4C nanowire, where discrete Ni6Si2B nanorods are embedded in the nanowire in a peapod form. The deformation of the nanowire provides a higher order scaling effect between conductivity and deformation strain, thus allowing the potentials of position and force sensing at the picoscale. PMID:26457662

  10. Minimizing distortion and internal forces in truss structures by simulated annealing

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.; Padula, Sharon L.

    1990-01-01

    Inaccuracies in the length of members and the diameters of joints of large space structures may produce unacceptable levels of surface distortion and internal forces. Here, two discrete optimization problems are formulated, one to minimize surface distortion (DSQRMS) and the other to minimize internal forces (FSQRMS). Both of these problems are based on the influence matrices generated by a small-deformation linear analysis. Good solutions are obtained for DSQRMS and FSQRMS through the use of a simulated annealing heuristic.

  11. America in Transition: The International Frontier. Report of the Task Force on International Education.

    ERIC Educational Resources Information Center

    National Governors' Association, Washington, DC.

    More than ever, U.S. economic well-being is intertwined with that of other countries through expanding international trade, financial markets, and investments. National security, and even world stability, depend upon U.S. understanding of and communication with other countries. Therefore, international education must be an integral part of the…

  12. Numerical Simulations for Distribution Characteristics of Internal Forces on Segments of Tunnel Linings

    NASA Astrophysics Data System (ADS)

    Li, Shouju; Shangguan, Zichang; Cao, Lijuan

    A procedure based on FEM is proposed to simulate interaction between concrete segments of tunnel linings and soils. The beam element named as Beam 3 in ANSYS software was used to simulate segments. The ground loss induced from shield tunneling and segment installing processes is simulated in finite element analysis. The distributions of bending moment, axial force and shear force on segments were computed by FEM. The commutated internal forces on segments will be used to design reinforced bars on shield linings. Numerically simulated ground settlements agree with observed values.

  13. Force.

    ERIC Educational Resources Information Center

    Gamble, Reed

    1989-01-01

    Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

  14. Analysis of Korean Students' International Mobility by 2-D Model: Driving Force Factor and Directional Factor

    ERIC Educational Resources Information Center

    Park, Elisa L.

    2009-01-01

    The purpose of this study is to understand the dynamics of Korean students' international mobility to study abroad by using the 2-D Model. The first D, "the driving force factor," explains how and what components of the dissatisfaction with domestic higher education perceived by Korean students drives students' outward mobility to seek foreign…

  15. Calculation of internal valence force constants for XY 6( Oh) octahedral molecules

    NASA Astrophysics Data System (ADS)

    Fernandez-Gomez, Manuel; Lopez-Gonzalez, Juan Jesus; Cardenete Espinosa, Antonio

    1990-04-01

    The valence force constants have been calculated in terms of simple dependent rectilinear internal co-ordinates for a series of XY 6 octahedral molecules that have been amply studied from a vibrational point of view, i.e. the hexafluorides of sulphur, selenium, molybdenum, tungsten and uranium. The calculations have been carried out using the most recent force constants in symmetry co-ordinates to appear in the literature and following Kuczera's treatment, according to which the indetermination of the internal valence force constants involved in redundancies can be solved by using the transformation F* R= WTWFRWTW, which he calls the pure vibrational force field. The results show that the eleven FR dependent constants are reduced to seven F* R independent constants, the same number as the FS independent force constants. This is because of the zero value of the ƒ'* dα constants and the relationships ƒ* dα= -ƒ″* dα ƒ* αα = -ƒ″* αα ƒ* α=-2ƒ'* αα-ƒ'″* αα that are obtained from the combination of the above mentioned F* R transformation and the sum rule in Kuczera's treatment. These latter relationships can be obtained from the interactions between the displacement coordinates with which they are associated. This has allowed individual values to be assigned to the bending, bending—bending and stretching—bending constants for the above mentioned molecules without the need for recourse to any model whatsoever.

  16. Dynamics of regenerative chatter and internal resonance in milling process with structural and cutting force nonlinearities

    NASA Astrophysics Data System (ADS)

    Moradi, Hamed; Movahhedy, Mohammad R.; Vossoughi, Gholamreza

    2012-07-01

    In this paper, internal resonance and nonlinear dynamics of regenerative chatter in milling process is investigated. An extended dynamic model of the peripheral milling process including both structural and cutting force nonlinearities is presented. Closed form expressions for the nonlinear cutting forces are derived through their Fourier series components. In the presence of the large vibration amplitudes, the loss of contact effect is included in this model. Using the multiple-scales approach, analytical approximate response of the delayed nonlinear system is obtained. Considering the internal resonance dynamics (i.e. mode coupling), the energy transfer between the coupled x-y modes is studied. The results show that during regenerative chatter under specific cutting conditions, one mode can decay. Furthermore, it is possible to adjust the rate at which the x-mode (or y-mode) decays by implementation of the internal resonance. Therefore, under both internal resonance and regenerative chatter conditions, it is possible to suppress the undesirable vibration of one mode (direction) in which accurate surface finish is required. Under the steady-state motion, jump phenomenon is investigated for the process with regenerative chatter under various cutting conditions. Moreover, the effects of structural and cutting force nonlinearities on the stability lobes diagram of the process are investigated.

  17. Perturbation analysis of internal balancing for lightly damped mechanical systems with gyroscopic and circulatory forces

    NASA Technical Reports Server (NTRS)

    Blelloch, P. A.; Mingori, D. L.; Wei, J. D.

    1987-01-01

    Approximate expressions are developed for internally balanced singular values corresponding to the modes of mechanical systems with gyroscopic forces, light damping, and small circulatory forces. A brief overview is first given of the balanced realization model reduction method, including a discussion of recent work. The models considered are defined, and a perturbation analysis is used to show that the modal representation becomes asymptotically balanced as damping reduces to zero. The approximate balanced singular values are calculated, and a simple example of a flexible, dual-spin spacecraft is given as an illustration of the results.

  18. Bacillus subtilis Bacteria Generate an Internal Mechanical Force within a Biofilm.

    PubMed

    Douarche, Carine; Allain, Jean-Marc; Raspaud, Eric

    2015-11-17

    A key issue in understanding why biofilms are the most prevalent mode of bacterial life is the origin of the degree of resistance and protection that bacteria gain from self-organizing into biofilm communities. Our experiments suggest that their mechanical properties are a key factor. Experiments on pellicles, or floating biofilms, of Bacillus subtilis showed that while they are multiplying and secreting extracellular substances, bacteria create an internal force (associated with a -80±25 Pa stress) within the biofilms, similar to the forces that self-equilibrate and strengthen plants, organs, and some engineered buildings. Here, we found that this force, or stress, is associated with growth-induced pressure. Our observations indicate that due to such forces, biofilms spread after any cut or ablation by up to 15-20% of their initial size. The force relaxes over very short timescales (tens of milliseconds). We conclude that this force helps bacteria to shape the biofilm, improve its mechanical resistance, and facilitate its invasion and self-repair. PMID:26588577

  19. Interactions between internal forces, body stiffness, and fluid environment in a neuromechanical model of lamprey swimming

    PubMed Central

    Tytell, Eric D.; Hsu, Chia-Yu; Williams, Thelma L.; Cohen, Avis H.; Fauci, Lisa J.

    2010-01-01

    Animal movements result from a complex balance of many different forces. Muscles produce force to move the body; the body has inertial, elastic, and damping properties that may aid or oppose the muscle force; and the environment produces reaction forces back on the body. The actual motion is an emergent property of these interactions. To examine the roles of body stiffness, muscle activation, and fluid environment for swimming animals, a computational model of a lamprey was developed. The model uses an immersed boundary framework that fully couples the Navier–Stokes equations of fluid dynamics with an actuated, elastic body model. This is the first model at a Reynolds number appropriate for a swimming fish that captures the complete fluid-structure interaction, in which the body deforms according to both internal muscular forces and external fluid forces. Results indicate that identical muscle activation patterns can produce different kinematics depending on body stiffness, and the optimal value of stiffness for maximum acceleration is different from that for maximum steady swimming speed. Additionally, negative muscle work, observed in many fishes, emerges at higher tail beat frequencies without sensory input and may contribute to energy efficiency. Swimming fishes that can tune their body stiffness by appropriately timed muscle contractions may therefore be able to optimize the passive dynamics of their bodies to maximize peak acceleration or swimming speed. PMID:21037110

  20. The bacteriophage straight phi29 portal motor can package DNA against a large internal force.

    PubMed

    Smith, D E; Tans, S J; Smith, S B; Grimes, S; Anderson, D L; Bustamante, C

    2001-10-18

    As part of the viral infection cycle, viruses must package their newly replicated genomes for delivery to other host cells. Bacteriophage straight phi29 packages its 6.6-microm long, double-stranded DNA into a 42 x 54 nm capsid by means of a portal complex that hydrolyses ATP. This process is remarkable because entropic, electrostatic and bending energies of the DNA must be overcome to package the DNA to near-crystalline density. Here we use optical tweezers to pull on single DNA molecules as they are packaged, thus demonstrating that the portal complex is a force-generating motor. This motor can work against loads of up to 57 pN on average, making it one of the strongest molecular motors reported to date. Movements of over 5 microm are observed, indicating high processivity. Pauses and slips also occur, particularly at higher forces. We establish the force-velocity relationship of the motor and find that the rate-limiting step of the motor's cycle is force dependent even at low loads. Notably, the packaging rate decreases as the prohead is filled, indicating that an internal force builds up to approximately 50 pN owing to DNA confinement. Our data suggest that this force may be available for initiating the ejection of the DNA from the capsid during infection. PMID:11607035

  1. Internal versus SST-forced atmospheric variability as simulated by an atmospheric general circulation model

    SciTech Connect

    Harzallah, A.; Sadourny, R.

    1995-03-01

    The variability of atmospheric flow is analyzed by separating it into an internal part due to atmospheric dynamics only and an external (or forced) part due to the variability of sea surface temperature forcing. The two modes of variability are identified by performing an ensemble of seven independent long-term simulations of the atmospheric response to observed SST (1970-1988) with the LMD atmospheric general circulation model. The forced variability is defined from the analysis of the ensemble mean and the internal variability from the analysis of deviations from the ensemble mean. Emphasis is put on interannual variability of sea level pressure and 500-hPa geopotential height for the Northern Hemisphere winter. In view of the large systematic errors related to the relatively small number of realizations, unbiased variance estimators have been developed. Although statistical significance is not reached in some extratropical regions, large significant extratropical responses are found at the North Pacific-Alaska sector for SLP and over western Canada and the Aleutians for 500-hPa geopotential height. The influence of SST variations on internal variability is also examined by using a 7-year simulation using the climatological SST seasonal cycle. It is found that interannual SST changes strongly influence the geographical distribution of internal variability; in particular, it tends to increase it over oceans. EOF decompositions, showing that the model realistically simulates the leading observed variability modes. The geographical structure of internal variability patterns is found to be similar to that of total variability, although similar modes tend to evolve rather differently in time. The zonally symmetric seesaw dominates the internal variability for both observed and climatologically prescribed SST. 46 refs., 15 figs., 3 tabs.

  2. Global patterns of temperature response to climate forcings and internal climate oscillations

    NASA Astrophysics Data System (ADS)

    Mikšovský, Jiří; Pišoft, Petr

    2014-05-01

    Within the frame of the research of past climate behavior, substantial attention is often paid to the issue of attribution, i.e. identification of the factors responsible for observed variability and quantification of their effects. Here, we apply a regression-based time series analysis to identify and separate the contributions of various external and internal forcing factors to global temperature field, revealing the geographical structure of the connections between the forcings and temperature, and evaluating strength and statistical significance of these links. The explanatory variables considered represent external climate forcings (greenhouse gasses concentration, solar activity, major volcanic eruptions) as well as prominent internal oscillations in the climate system (Southern Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation, Trans Polar Index-related circulation). Results for two datasets of gridded monthly temperature (20th Century Reanalysis and Berkeley Earth) are shown and compared, on a target period covering years 1901-2010. Along with visualization of the spatial patterns associated with contributions of individual forcing factors to the temperature field, their temporal variations (both seasonal and long-term) are also presented and discussed.

  3. Dispersion Forces and the Molecular Origin of Internal Friction in Protein.

    PubMed

    Sashi, Pulikallu; Ramakrishna, Dasari; Bhuyan, Abani K

    2016-08-23

    Internal friction in macromolecules is one of the curious phenomena that control conformational changes and reaction rates. It is held here that dispersion interactions and London-van der Waals forces between nonbonded atoms are major contributors to internal friction. To demonstrate this, the flipping motion of aromatic rings of F10 and Y97 amino acid residues of cytochrome c has been studied in glycerol/water mixtures by cross relaxation-suppressed exchange nuclear magnetic resonance spectroscopy. The ring-flip rate is highly overdamped by glycerol, but this is not due to the effect of protein-solvent interactions on the Brownian dynamics of the protein, because glycerol cannot penetrate into the protein to slow the internal collective motions. Sound velocity in the protein under matching solvent conditions shows that glycerol exerts its effect by rather smothering the protein interior to produce reduced molecular compressibility and root-mean-square volume fluctuation (δVRMS), implying an increased number of dispersion interactions of nonbonded atoms. Hence, δVRMS can be used as a proxy for internal friction. By using the ansatz that internal friction is related to nonbonded interactions by the equation f(n) = f0 + f1n + f2n(2) + ..., where the variable n is the extent of nonbonded interactions with fi coefficients, the barrier to aromatic ring rotation is found to be flat. Also interesting is the appearance of a turnover region in the δVRMS dependence of the ring-flip rate, suggesting anomalous internal diffusion. We conclude that cohesive forces among nonbonded atoms are major contributors to the molecular origin of internal friction. PMID:27479029

  4. A Southwest Pacific Coral Perspective on ENSO Variability: Precessional Forcing vs. Internal Variability

    NASA Astrophysics Data System (ADS)

    Quinn, T. M.; Partin, J. W.; Thirumalai, K.; Maupin, C. R.; Vara, M. A.; Shen, C. C.; Taylor, F. W.

    2014-12-01

    ENSO variability is manifest in the western Pacific through heat and moisture exchanges associated with the Western Pacific Warm Pool (WPWP) and the South Pacific Convergence Zone (SPCZ). Forward modeling (pseudoproxy analysis) results and published coral proxy records from the tropical Pacific indicate that in addition to the central and eastern Pacific regions, corals from the WPWP and SPCZ regions skillfully record ENSO variability. Some studies suggest that precessional forcing directly reduces/enhances ENSO variability. Other studies suggest that internal variability is the primary control on Holocene ENSO changes. Herein, we use coral proxy records from the tropical Pacific and numerical simulations to better understand the response of ENSO to precessional forcing and internal variability. We extend the coral record of ENSO variability using a new modern coral record from the Solomon Islands (1716-2008 CE) and a select suite of Holocene fossil coral records from the WPWP. The new modern coral record captures large ENSO events with considerable skill, providing new evidence for potential large ENSO events during the early 18th and 19th centuries, events that are not represented in current coral and/or multi-proxy reconstructions. We also note that long periods of reduced ENSO activity can occur during intervals with near constant precessional forcing at modern values. The fossil coral records provide discrete time windows into ENSO variability over the Holocene. These records provide evidence of similar patterns of ENSO activity during intervals with different precessional configurations. The modern and fossil coral records imply a strong influence of internal variability in the modulation of ENSO, which may make it difficult to establish a direct control of precessional forcing on ENSO variability over the Holocene.

  5. Understanding the Southeast United States "Warming Hole": Forced Response or Internal Variability?

    NASA Astrophysics Data System (ADS)

    Mascioli, N. R.; Fiore, A. M.; Previdi, M. J.

    2015-12-01

    Observed summertime temperatures in the southeast United States did not change significantly from 1895 to 2011 despite the fact that temperatures averaged over the entire U.S. have increased by 0.65°C during this time. A variety of possible causes have been suggested to explain this southeast U.S. "warming hole", including changes in Pacific and Atlantic sea surface temperatures (SSTs) due to internal variability, forcing from anthropogenic aerosols, and changes in local hydrology due to land-use change. Here we investigate some of these mechanisms using the GFDL-CM3 chemistry climate model, one of the CMIP5 models best able to capture the observed warming hole. We use the "aerosol only" and "greenhouse gas only" single forcing simulations to further develop our understanding of the potential drivers of the warming hole. We find that in both simulations, temperatures in the southeast U.S. exhibit a weaker response to anthropogenic forcing compared with the rest of the country, suggesting a preferred regional mode of response that is largely independent of the type of forcing. Increasing anthropogenic aerosols weaken the Bermuda High, reducing the transport of moisture into the southeast U.S. from the Gulf of Mexico. Accordingly, total cloud fraction, precipitation, and soil moisture content are also reduced. These changes are associated with an increase in the surface absorption of shortwave (SW) radiation, thus offsetting the expected cooling due to the radiative effects of the aerosols, and creating a "cooling hole" in the aerosol only simulation. In the greenhouse gas only simulation, there is an opposite-signed response, with increases in the Bermuda High strength and moisture flux into the southeast U.S, and decreases in the surface SW absorption. Finally, the impacts of Pacific and Atlantic SST changes, both forced and internal, on the simulated temperature in the southeast U.S. are also discussed.

  6. 32 CFR 536.113 - Assistance to foreign forces for claims arising under international agreements (as to claims...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... under international agreements (as to claims arising in the United States). 536.113 Section 536.113... AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.113 Assistance to foreign forces for claims arising under international agreements (as to claims arising in the United States)....

  7. Foraging at the Edge of Chaos: Internal Clock versus External Forcing

    NASA Astrophysics Data System (ADS)

    Nicolis, S. C.; Fernández, J.; Pérez-Penichet, C.; Noda, C.; Tejera, F.; Ramos, O.; Sumpter, D. J. T.; Altshuler, E.

    2013-06-01

    Activity rhythms in animal groups arise both from external changes in the environment, as well as from internal group dynamics. These cycles are reminiscent of physical and chemical systems with quasiperiodic and even chaotic behavior resulting from “autocatalytic” mechanisms. We use nonlinear differential equations to model how the coupling between the self-excitatory interactions of individuals and external forcing can produce four different types of activity rhythms: quasiperiodic, chaotic, phase locked, and displaying over or under shooting. At the transition between quasiperiodic and chaotic regimes, activity cycles are asymmetrical, with rapid activity increases and slower decreases and a phase shift between external forcing and activity. We find similar activity patterns in ant colonies in response to varying temperature during the day. Thus foraging ants operate in a region of quasiperiodicity close to a cascade of transitions leading to chaos. The model suggests that a wide range of temporal structures and irregularities seen in the activity of animal and human groups might be accounted for by the coupling between collectively generated internal clocks and external forcings.

  8. Binaries Traveling through a Gaseous Medium: Dynamical Drag Forces and Internal Torques

    NASA Astrophysics Data System (ADS)

    Sánchez-Salcedo, F. J.; Chametla, Raul O.

    2014-10-01

    Using time-dependent linear theory, we investigate the morphology of the gravitational wake induced by a binary, whose center of mass moves at velocity {\\boldsymbol {V}}_cm against a uniform background of gas. For simplicity, we assume that the components of the binary are on circular orbits about their common center of mass. The consequences of dynamical friction is twofold. First, gas dynamical friction may drag the center of mass of the binary and cause the binary to migrate. Second, drag forces also induce a braking torque, which causes the orbits of the components of the binary to shrink. We compute the drag forces acting on one component of the binary due to the gravitational interaction with its own wake. We show that the dynamical friction force responsible for decelerating the center of mass of the binary is smaller than it is in the point-mass case because of the loss of gravitational focusing. We show that the braking internal torque depends on the Mach numbers of each binary component about their center of mass, and also on the Mach number of the center of mass of the binary. In general, the internal torque decreases with increasing the velocity of the binary relative to the ambient gas cloud. However, this is not always the case. We also mention the relevance of our results to the period distribution of binaries.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Binaries traveling through a gaseous medium: dynamical drag forces and internal torques

    SciTech Connect

    Sánchez-Salcedo, F. J.; Chametla, Raul O.

    2014-10-20

    Using time-dependent linear theory, we investigate the morphology of the gravitational wake induced by a binary, whose center of mass moves at velocity V{sub cm} against a uniform background of gas. For simplicity, we assume that the components of the binary are on circular orbits about their common center of mass. The consequences of dynamical friction is twofold. First, gas dynamical friction may drag the center of mass of the binary and cause the binary to migrate. Second, drag forces also induce a braking torque, which causes the orbits of the components of the binary to shrink. We compute the drag forces acting on one component of the binary due to the gravitational interaction with its own wake. We show that the dynamical friction force responsible for decelerating the center of mass of the binary is smaller than it is in the point-mass case because of the loss of gravitational focusing. We show that the braking internal torque depends on the Mach numbers of each binary component about their center of mass, and also on the Mach number of the center of mass of the binary. In general, the internal torque decreases with increasing the velocity of the binary relative to the ambient gas cloud. However, this is not always the case. We also mention the relevance of our results to the period distribution of binaries.

  11. Report of the Cost Assessment and Validation Task Force on the International Space Station

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Cost Assessment and Validation (CAV) Task Force was established for independent review and assessment of cost, schedule and partnership performance on the International Space Station (ISS) Program. The CAV Task Force has made the following key findings: The International Space Station Program has made notable and reasonable progress over the past four years in defining and executing a very challenging and technically complex effort. The Program size, complexity, and ambitious schedule goals were beyond that which could be reasonably achieved within the $2.1 billion annual cap or $17.4 billion total cap. A number of critical risk elements are likely to have an adverse impact on the International Space Station cost and schedule. The schedule uncertainty associated with Russian implementation of joint Partnership agreements is the major threat to the ISS Program. The Fiscal Year (FY) 1999 budget submission to Congress is not adequate to execute the baseline ISS Program, cover normal program growth, and address the known critical risks. Additional annual funding of between $130 million and $250 million will be required. Completion of ISS assembly is likely to be delayed from one to three years beyond December 2003.

  12. Research priorities and plans for the International Space Station-results of the 'REMAP' Task Force

    NASA Technical Reports Server (NTRS)

    Kicza, M.; Erickson, K.; Trinh, E.

    2003-01-01

    Recent events in the International Space Station (ISS) Program have resulted in the necessity to re-examine the research priorities and research plans for future years. Due to both technical and fiscal resource constraints expected on the International Space Station, it is imperative that research priorities be carefully reviewed and clearly articulated. In consultation with OSTP and the Office of Management and budget (OMB), NASA's Office of Biological and Physical Research (OBPR) assembled an ad-hoc external advisory committee, the Biological and Physical Research Maximization and Prioritization (REMAP) Task Force. This paper describes the outcome of the Task Force and how it is being used to define a roadmap for near and long-term Biological and Physical Research objectives that supports NASA's Vision and Mission. Additionally, the paper discusses further prioritizations that were necessitated by budget and ISS resource constraints in order to maximize utilization of the International Space Station. Finally, a process has been developed to integrate the requirements for this prioritized research with other agency requirements to develop an integrated ISS assembly and utilization plan that maximizes scientific output. c2003 American Institute of Aeronautics and Astronautics. Published by Elsevier Science Ltd. All rights reserved.

  13. Research priorities and plans for the International Space Station-results of the 'REMAP' Task Force.

    PubMed

    Kicza, M; Erickson, K; Trinh, E

    2003-01-01

    Recent events in the International Space Station (ISS) Program have resulted in the necessity to re-examine the research priorities and research plans for future years. Due to both technical and fiscal resource constraints expected on the International Space Station, it is imperative that research priorities be carefully reviewed and clearly articulated. In consultation with OSTP and the Office of Management and budget (OMB), NASA's Office of Biological and Physical Research (OBPR) assembled an ad-hoc external advisory committee, the Biological and Physical Research Maximization and Prioritization (REMAP) Task Force. This paper describes the outcome of the Task Force and how it is being used to define a roadmap for near and long-term Biological and Physical Research objectives that supports NASA's Vision and Mission. Additionally, the paper discusses further prioritizations that were necessitated by budget and ISS resource constraints in order to maximize utilization of the International Space Station. Finally, a process has been developed to integrate the requirements for this prioritized research with other agency requirements to develop an integrated ISS assembly and utilization plan that maximizes scientific output. PMID:14649263

  14. Cost Assessment and Validation Task Force on the International Space Station

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Cost Assessment and Validation (CAV) Task Force was established for independent review and assessment of cost, schedule and partnership performance on the International Space Station (ISS) Program. The CAV Task Force has made the following key findings: The International Space Station Program has made notable and reasonable progress over the past four years in defining and executing a very challenging and technically complex effort; The Program, size, complexity, and ambitious schedule goals were beyond that which could be reasonably achieved within the $2.1 billion annual cap or $17.4 billion total cap; A number of critical risk elements are likely to have an adverse impact on the International Space Station cost and schedule; The schedule uncertainty associated with Russian implementation of joint Partnership agreements is the major threat to the ISS Program; The Fiscal Year (FY) 1999 budget submission to Congress is not adequate to execute the baseline ISS Program, cover normal program, growth, and address the known critical risks. Additional annual funding of between $130 million and $250 million will be required; and Completion of ISS assembly is likely to be delayed from, one to three years beyond December 2003.

  15. Regional synchrony of temperature variation and internal wave forcing along the Florida Keys reef tract

    NASA Astrophysics Data System (ADS)

    Leichter, James J.; Stokes, M. Dale; Vilchis, L. Ignacio; Fiechter, Jerome

    2014-01-01

    Analysis of 10 year temperature records collected along the Florida Keys reef tract (FLKRT) reveals strong, regional-scale synchrony in high-frequency temperature variation suggestive of internal wave forcing at predominately semidiurnal frequencies. In each year and at all sites, the amplitude of semidiurnal temperature variation was greatest from March to September, and markedly lower from October to February. Comparisons of the semidiurnal component of the temperature variation among sites suggest complex patterns in the arrival of internal waves, with highest cross correlation among closely spaced sites and synchrony in periods of enhanced internal wave activity across the length of the FLKRT, particularly in summer. The periods of enhanced semidiurnal temperature variation at the 20 and 30 m isobaths on the reef slopes appear to be associated with the dynamics of the Florida Current and the onshore movement of warm fronts preceding the passage of Florida Current frontal eddies. Regional-scale satellite altimetry observations suggest temporal linkages to sea surface height anomalies in the Loop Current (upstream of the Florida Current) and setup of the Tortugas Gyre. The synchronized forcing of cool water onto the reef slope sites across the FLKRT is likely to affect physiological responses to temperature variation in corals and other ectothermic organisms, as well as larval transport and nutrient dynamics with the potential for regionally coherent pulses of larvae and nutrients arriving on reef slopes across the FLKRT.

  16. Internal and Forced Low-Frequency Surface Temperature Variability at Global and Regional Scales

    NASA Astrophysics Data System (ADS)

    Mann, M. E.; Steinman, B. A.; Miller, S. K.

    2014-12-01

    There is evidence for internal models of decadal and multidecadal surface temperature variability that possess relatively narrowband spectral signatures. Among these are the so-called Atlantic Multidecadal Oscillation ("AMO") and Pacific Decadal Oscillation ("PDO"). Separating these internal variability components from long-term forced temperature changes, however, is a non-trivial task. We apply a semi-empirical approach that combines climate observations and model-simulations to estimate Atlantic- and Pacific-based internal multidecadal variability (termed 'AMO' and 'PMO', respectively). Using analyses of coupled global climate model simulations, we show that our approach correctly identifies the internal variability components, while several alternative approaches overestimate and misidentify these components and their contribution to hemispheric mean temperatures. Using our method, the AMO and PMO are found to project in nearly equal proportion onto internal multidecadal variability in Northern Hemisphere mean temperature (termed 'NMO'). A recent NMO cooling trend which contributes to the slowdown or "false pause" in warming of the past decade is seen to reflect a competition between a modest positive peak in the AMO and a substantially negative-trending PMO.

  17. Topography and Mechanical Property Mapping of International Simple Glass Surfaces with Atomic Force Microscopy

    SciTech Connect

    Pierce, Eric M

    2014-01-01

    Quantitative Nanomechanical Peak Force (PF-QNM) TappingModeTM atomic force microscopy measurements are presented for the first time on polished glass surfaces. The PF-QNM technique allows for topography and mechanical property information to be measured simultaneously at each pixel. Results for the international simple glass which represents a simplified version of SON68 glass suggests an average Young s modulus of 78.8 15.1 GPa is within the experimental error of the modulus measured for SON68 glass (83.6 2 GPa) with conventional approaches. Application of the PF-QNM technique will be extended to in situ glass corrosion experiments with the goal of gaining atomic-scale insights into altered layer development by exploiting the mechanical property differences that exist between silica gel (e.g., altered layer) and pristine glass surface.

  18. Report by the International Space Station (ISS) Management and Cost Evaluation (IMCE) Task Force

    NASA Technical Reports Server (NTRS)

    Young, A. Thomas; Kellogg, Yvonne (Technical Monitor)

    2001-01-01

    The International Space Station (ISS) Management and Cost Evaluation Task Force (IMCE) was chartered to conduct an independent external review and assessment of the ISS cost, budget, and management. In addition, the Task Force was asked to provide recommendations that could provide maximum benefit to the U.S. taxpayers and the International Partners within the President's budget request. The Task Force has made the following principal findings: (1) The ISS Program's technical achievements to date, as represented by on-orbit capability, are extraordinary; (2) The Existing ISS Program Plan for executing the FY 02-06 budget is not credible; (3) The existing deficiencies in management structure, institutional culture, cost estimating, and program control must be acknowledged and corrected for the Program to move forward in a credible fashion; (4) Additional budget flexibility, from within the Office of Space Flight (OSF) must be provided for a credible core complete program; (5) The research support program is proceeding assuming the budget that was in place before the FY02 budget runout reduction of $1B; (6) There are opportunities to maximize research on the core station program with modest cost impact; (7) The U.S. Core Complete configuration (three person crew) as an end-state will not achieve the unique research potential of the ISS; (8) The cost estimates for the U.S.-funded enhancement options (e.g., permanent seven person crew) are not sufficiently developed to assess credibility. After these findings, the Task Force has formulated several primary recommendations which are published here and include: (1) Major changes must be made in how the ISS program is managed; (2) Additional cost reductions are required within the baseline program; (3) Additional funds must be identified and applied from the Human Space Flight budget; (4) A clearly defined program with a credible end-state, agreed to by all stakeholders, must be developed and implemented.

  19. International PV QA Task Force's Proposed Comparative Rating System for PV Modules: Preprint

    SciTech Connect

    Wohlgemuth, J.; Kurtz, S.

    2014-10-01

    The International PV Quality Assurance Task Force is developing a rating system that provides comparative information about the relative durability of PV modules. Development of accelerated stress tests that can provide such comparative information is seen as a major step toward being able to predict PV module service life. This paper will provide details of the ongoing effort to determine the format of such an overall module rating system. The latest proposal is based on using three distinct climate zones as defined in IEC 60721-2-1 for two different mounting systems. Specific stresses beyond those used in the qualification tests are being developed for each of the selected climate zones.

  20. The International Society for Bipolar Disorders (ISBD) Task Force Report on Antidepressant Use in Bipolar Disorders

    PubMed Central

    Pacchiarotti, Isabella; Bond, David J.; Baldessarini, Ross J.; Nolen, Willem A.; Grunze, Heinz; Licht, Rasmus W.; Post, Robert M.; Berk, Michael; Goodwin, Guy M.; Sachs, Gary S.; Tondo, Leonardo; Findling, Robert L.; Youngstrom, Eric A.; Tohen, Mauricio; Undurraga, Juan; González-Pinto, Ana; Goldberg, Joseph F.; Yildiz, Ayşegül; Altshuler, Lori L.; Calabrese, Joseph R.; Mitchell, Philip B.; Thase, Michael E.; Koukopoulos, Athanasios; Colom, Francesc; Frye, Mark A.; Malhi, Gin S.; Fountoulakis, Konstantinos N.; Vázquez, Gustavo; Perlis, Roy H.; Ketter, Terence A.; Cassidy, Frederick; Akiskal, Hagop; Azorin, Jean-Michel; Valentí, Marc; Mazzei, Diego Hidalgo; Lafer, Beny; Kato, Tadafumi; Mazzarini, Lorenzo; Martínez-Aran, Anabel; Parker, Gordon; Souery, Daniel; Özerdem, Ayşegül; McElroy, Susan L.; Girardi, Paolo; Bauer, Michael; Yatham, Lakshmi N.; Zarate, Carlos A.; Nierenberg, Andrew A.; Birmaher, Boris; Kanba, Shigenobu; El-Mallakh, Rif S.; Serretti, Alessandro; Rihmer, Zoltan; Young, Allan H.; Kotzalidis, Georgios D.; MacQueen, Glenda M.; Bowden, Charles L.; Ghaemi, S. Nassir; Lopez-Jaramillo, Carlos; Rybakowski, Janusz; Ha, Kyooseob; Perugi, Giulio; Kasper, Siegfried; Amsterdam, Jay D.; Hirschfeld, Robert M.; Kapczinski, Flávio; Vieta, Eduard

    2014-01-01

    Objective The risk-benefit profile of antidepressant medications in bipolar disorder is controversial. When conclusive evidence is lacking, expert consensus can guide treatment decisions. The International Society for Bipolar Disorders (ISBD) convened a task force to seek consensus recommendations on the use of antidepressants in bipolar disorders. Method An expert task force iteratively developed consensus through serial consensus-based revisions using the Delphi method. Initial survey items were based on systematic review of the literature. Subsequent surveys included new or reworded items and items that needed to be rerated. This process resulted in the final ISBD Task Force clinical recommendations on antidepressant use in bipolar disorder. Results There is striking incongruity between the wide use of and the weak evidence base for the efficacy and safety of antidepressant drugs in bipolar disorder. Few well-designed, long-term trials of prophylactic benefits have been conducted, and there is insufficient evidence for treatment benefits with antidepressants combined with mood stabilizers. A major concern is the risk for mood switch to hypomania, mania, and mixed states. Integrating the evidence and the experience of the task force members, a consensus was reached on 12 statements on the use of antidepressants in bipolar disorder. Conclusions Because of limited data, the task force could not make broad statements endorsing antidepressant use but acknowledged that individual bipolar patients may benefit from antidepressants. Regarding safety, serotonin reuptake inhibitors and bupropion may have lower rates of manic switch than tricyclic and tetracyclic antidepressants and norepinephrine-serotonin reuptake inhibitors. The frequency and severity of antidepressant-associated mood elevations appear to be greater in bipolar I than bipolar II disorder. Hence, in bipolar I patients antidepressants should be prescribed only as an adjunct to mood-stabilizing medications

  1. Utilizing intentional internal resonance to achieve multi-harmonic atomic force microscopy.

    PubMed

    Jeong, Bongwon; Pettit, Chris; Dharmasena, Sajith; Keum, Hohyun; Lee, Joohyung; Kim, Jungkyu; Kim, Seok; McFarland, D Michael; Bergman, Lawrence A; Vakakis, Alexander F; Cho, Hanna

    2016-03-29

    During dynamic atomic force microscopy (AFM), the deflection of a scanning cantilever generates multiple frequency terms due to the nonlinear nature of AFM tip-sample interactions. Even though each frequency term is reasonably expected to encode information about the sample, only the fundamental frequency term is typically decoded to provide topographic mapping of the measured surface. One of main reasons for discarding higher harmonic signals is their low signal-to-noise ratio. Here, we introduce a new design concept for multi-harmonic AFM, exploiting intentional nonlinear internal resonance for the enhancement of higher harmonics. The nonlinear internal resonance, triggered by the non-smooth tip-sample dynamic interactions, results in nonlinear energy transfers from the directly excited fundamental bending mode to the higher-frequency mode and, hence, enhancement of the higher harmonic of the measured response. It is verified through detailed theoretical and experimental study that this AFM design can robustly incorporate the required internal resonance and enable high-frequency AFM measurements. Measurements on an inhomogeneous polymer specimen demonstrate the efficacy of the proposed design, namely that the higher harmonic of the measured response is capable of enhanced simultaneous topography imaging and compositional mapping, exhibiting less crosstalk with an abrupt height change. PMID:26883303

  2. Internal and external forcing of sea level variability in the Black Sea

    NASA Astrophysics Data System (ADS)

    Volkov, Denis L.; Landerer, Felix W.

    2015-11-01

    The variability of sea level in the Black Sea is forced by a combination of internal and external processes of atmospheric, oceanic, and terrestrial origin. We use a combination of satellite altimetry and gravity, tide gauge, river discharge, and atmospheric re-analysis data to provide a comprehensive up-to-date analysis of sea level variability in the Black Sea and to quantify the role of different environmental factors that force the variability. The Black Sea is part of a large-scale climatic system that includes the Mediterranean and the North Atlantic. The seasonal sea level budget shows similar contributions of fresh water fluxes (precipitation, evaporation, and river discharge) and the Black Sea outflow, while the impact of the net surface heat flux is smaller although not negligible. We find that the nonseasonal sea level time series in the Black and Aegean seas are significantly correlated, the latter leading by 1 month. This lag is attributed to the adjustment of sea level in the Black Sea to externally forced changes of sea level in the Aegean Sea and to the impact of river discharge. The nonseasonal sea level budget in the Black Sea is dominated by precipitation and evaporation over the sea itself, but external processes such as river discharge and changes in the outflow can also cause some large synoptic-scale sea level anomalies. Sea level is strongly coupled to terrestrial water storage over the Black Sea drainage basin, which is modulated by the North Atlantic Oscillation (NAO). We show that during the low/high NAO southwesterly/northeasterly winds near the Strait of Gibraltar and southerly/northerly winds over the Aegean Sea are able to dynamically increase/decrease sea level in the Mediterranean and Black seas, respectively.

  3. Systematic attribution of observed Southern Hemisphere circulation trends to external forcing and internal variability

    NASA Astrophysics Data System (ADS)

    Franzke, C. L. E.; O'Kane, T. J.; Monselesan, D. P.; Risbey, J. S.; Horenko, I.

    2015-09-01

    A critical question in the global warming debate concerns the causes of the observed trends of the Southern Hemisphere (SH) atmospheric circulation over recent decades. Secular trends have been identified in the frequency of occurrence of circulation regimes, namely the positive phase of the Southern Annular Mode (SAM) and the hemispheric wave-3 pattern which is associated with blocking. Previous studies into the causes of these secular trends have either been purely model based, have not included observational forcing data or have mixed external forcing with indices of internal climate variability impeding a systematic and unbiased attribution of the causes of the secular trends. Most model studies also focused mainly on the austral summer season. However, the changes to the storm tracks have occurred in all seasons and particularly in the austral winter and early spring when midlatitude blocking is most active and stratospheric ozone should not play a role. Here we systematically attribute the secular trends over the recent decades using a non-stationary clustering method applied to both reanalysis and observational forcing data from all seasons. While most previous studies emphasized the importance of stratospheric ozone depletion in causing austral summer SH circulation trends, we show observational evidence that anthropogenic greenhouse gas concentrations have been the major driver of these secular trends in the SAM and blocking when all seasons are considered. Our results suggest that the recovery of the ozone hole might delay the signal of global warming less strongly than previously thought and that effects from all seasons are likely crucial in understanding the causes of the secular trends.

  4. Systematic Attribution of Observed Southern Hemispheric Circulation Trends to External Forcing and Internal Variability

    NASA Astrophysics Data System (ADS)

    Franzke, Christian; O'Kane, Terence; Monselesan, Didier; Risbey, James; Horenko, Illia

    2015-04-01

    A critical question in the global warming debate concerns the causes of the observed trends of the Southern Hemisphere (SH) atmospheric circulation over recent decades. Secular trends have been identified in the frequency of occurrence of circulation regimes, namely the positive phase of the Southern Annular Mode (SAM) and the hemispheric wave 3 pattern which is associated with blocking. Previous studies into the causes of these secular trends have either been purely model based, have not included observational forcing data or have mixed external forcing with indices of internal climate variability impeding a systematic and unbiased attribution of the causes of the secular trends. Most model studies also focused mainly on the austral summer season. However, the changes to the storm tracks have occurred in all seasons and particularly in the winter and early spring when mid-latitude blocking is most active and stratospheric ozone plays no role. Here we systematically attribute the secular trends over the recent decades using a non-stationary clustering method applied to both reanalysis and observational forcing data from all seasons. While most previous studies emphasized the importance of stratospheric ozone depletion in causing summer SH circulation trends, we show observational evidence that anthropogenic greenhouse gas concentrations have been the major driver of these secular trends in the SAM and blocking when all seasons are considered. Our results suggest that the recovery of the ozone hole might delay the signal of global warming less strongly than previously thought and that seasonal effects are likely crucial in understanding the causes of the secular trends.

  5. Systematic attribution of observed southern hemispheric circulation trends to external forcing and internal variability

    NASA Astrophysics Data System (ADS)

    Franzke, C. L. E.; O'Kane, T. J.; Monselesan, D. P.; Risbey, J. S.; Horenko, I.

    2015-04-01

    A critical question in the global warming debate concerns the causes of the observed trends of the Southern Hemisphere (SH) atmospheric circulation over recent decades. Secular trends have been identified in the frequency of occurrence of circulation regimes, namely the positive phase of the Southern Annular Mode (SAM) and the hemispheric wave 3 pattern which is associated with blocking. Previous studies into the causes of these secular trends have either been purely model based, have not included observational forcing data or have mixed external forcing with indices of internal climate variability impeding a systematic and unbiased attribution of the causes of the secular trends. Most model studies also focused mainly on the austral summer season. However, the changes to the storm tracks have occurred in all seasons and particularly in the austral winter and early spring when mid-latitude blocking is most active and stratospheric ozone should not a play a role. Here we systematically attribute the secular trends over the recent decades using a non-stationary clustering method applied to both reanalysis and observational forcing data from all seasons. While most previous studies emphasized the importance of stratospheric ozone depletion in causing austral summer SH circulation trends, we show observational evidence that anthropogenic greenhouse gas concentrations have been the major driver of these secular trends in the SAM and blocking when all seasons are considered. Our results suggest that the recovery of the ozone hole might delay the signal of global warming less strongly than previously thought and that effects from all seasons are likely crucial in understanding the causes of the secular trends.

  6. Internally displaced "victims of armed conflict" in Colombia: the trajectory and trauma signature of forced migration.

    PubMed

    Shultz, James M; Garfin, Dana Rose; Espinel, Zelde; Araya, Ricardo; Oquendo, Maria A; Wainberg, Milton L; Chaskel, Roberto; Gaviria, Silvia L; Ordóñez, Anna E; Espinola, Maria; Wilson, Fiona E; Muñoz García, Natalia; Gómez Ceballos, Angela Milena; Garcia-Barcena, Yanira; Verdeli, Helen; Neria, Yuval

    2014-10-01

    While conflict-induced forced migration is a global phenomenon, the situation in Colombia, South America, is distinctive. Colombia has ranked either first or second in the number of internally displaced persons for 10 years, a consequence of decades of armed conflict compounded by high prevalence of drug trafficking. The displacement trajectory for displaced persons in Colombia proceeds through a sequence of stages: (1) pre-expulsion threats and vulnerability, (2) expulsion, (3) migration, (4) initial adaptation to relocation, (5) protracted resettlement (the end point for most forced migrants), and, rarely, (6) return to the community of origin. Trauma signature analysis, an evidence-based method that elucidates the physical and psychological consequences associated with exposures to harm and loss during disasters and complex emergencies, was used to identify the psychological risk factors and potentially traumatic events experienced by conflict-displaced persons in Colombia, stratified across the phases of displacement. Trauma and loss are experienced differentially throughout the pathway of displacement. PMID:25135775

  7. [Global and historical development of the IMETAF (International Molecular Epidemiology Task Force) in Mexico].

    PubMed

    Gorodezky, C

    1997-01-01

    IMETAF or International Molecular Epidemiology Task Force was created upon the enthusiasm of Janice Dorman, molecular epidemiologist at Pittsburgh University. Also, she was in charge of the WHO type I Diabetes world project called DIAMOND. As a result of this project done with Mexican scientists. The Scientific Committee of IMETAF was formed on July 28, 1993. The activities began. A national infrastructure survey was done to analyze the epidemiology and molecular biology capabilities; a directory of scientist in epidemiology and molecular biology was elaborated; a theoric and practical course on molecular epidemiology was organized during 1996 and a second one will be held in 1997; and a series of Workshops were done: cancer and leukemias; bacterial diseases; trypanosomiosis and leishmaniosis and viral diseases. The results of these academic activities were brought to the National Academy of Medicine to a 2 days workshop and to an International Symposium called Projection of molecular epidemiology in medicine, held on April 17, 1996. The papers are published in this number. The goal of IMETAF will continue promoting transfer of technology, stimulating formal training in molecular epidemiology and helping getting funds for collaborative projects. PMID:9504097

  8. Nomenclature of genetic movement disorders: Recommendations of the international Parkinson and movement disorder society task force.

    PubMed

    Marras, Connie; Lang, Anthony; van de Warrenburg, Bart P; Sue, Carolyn M; Tabrizi, Sarah J; Bertram, Lars; Mercimek-Mahmutoglu, Saadet; Ebrahimi-Fakhari, Darius; Warner, Thomas T; Durr, Alexandra; Assmann, Birgit; Lohmann, Katja; Kostic, Vladimir; Klein, Christine

    2016-04-01

    The system of assigning locus symbols to specify chromosomal regions that are associated with a familial disorder has a number of problems when used as a reference list of genetically determined disorders,including (I) erroneously assigned loci, (II) duplicated loci, (III) missing symbols or loci, (IV) unconfirmed loci and genes, (V) a combination of causative genes and risk factor genes in the same list, and (VI) discordance between phenotype and list assignment. In this article, we report on the recommendations of the International Parkinson and Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders and present a system for naming genetically determined movement disorders that addresses these problems. We demonstrate how the system would be applied to currently known genetically determined parkinsonism, dystonia, dominantly inherited ataxia, spastic paraparesis, chorea, paroxysmal movement disorders, neurodegeneration with brain iron accumulation, and primary familial brain calcifications. This system provides a resource for clinicians and researchers that, unlike the previous system, can be considered an accurate and criterion-based list of confirmed genetically determined movement disorders at the time it was last updated. © 2016 International Parkinson and Movement Disorder Society. PMID:27079681

  9. Internal resonance in forced vibration of coupled cantilevers subjected to magnetic interaction

    NASA Astrophysics Data System (ADS)

    Chen, Li-Qun; Zhang, Guo-Ce; Ding, Hu

    2015-10-01

    Forced vibration is investigated for two elastically connected cantilevers, under harmonic base excitation. One of the cantilevers is with a tip magnet repelled by a magnet fixed on the base. The cantilevers are uniform viscoelastic beams constituted by the Kelvin model. The system is formulated as a set of two linear partial differential equations with nonlinear boundary conditions. The method of multiple scales is developed to analyze the effects of internal resonances on the steady-state responses to external excitations in the nonlinear boundary problem of the partial differential equations. In the presence of 2:1 internal resonance, both the first and the second primary resonances are examined in detail. The analytical frequency-amplitude response relationships are derived from the solvability conditions. It is found that the frequency-amplitude response curves reveal typical nonlinear phenomena such as jumping and hysteresis in both primary resonances as well as saturation in the second primary resonance. The frequency-amplitude response curves may be converted from hardening-type single-jumping to double-jumpings, and further to softening-type single-jumping by adjusting the distance between two magnets. It is also found that the unstable parts of the frequency-amplitude response curves correspond to quasi-periodic motions. The finite difference scheme is proposed to discretize both the temporal and the spatial variables, and thus the numerical solutions can be calculated. The analytical results are supported by the numerical solutions.

  10. International veterinary epilepsy task force consensus report on epilepsy definition, classification and terminology in companion animals.

    PubMed

    Berendt, Mette; Farquhar, Robyn G; Mandigers, Paul J J; Pakozdy, Akos; Bhatti, Sofie F M; De Risio, Luisa; Fischer, Andrea; Long, Sam; Matiasek, Kaspar; Muñana, Karen; Patterson, Edward E; Penderis, Jacques; Platt, Simon; Podell, Michael; Potschka, Heidrun; Pumarola, Martí Batlle; Rusbridge, Clare; Stein, Veronika M; Tipold, Andrea; Volk, Holger A

    2015-01-01

    Dogs with epilepsy are among the commonest neurological patients in veterinary practice and therefore have historically attracted much attention with regard to definitions, clinical approach and management. A number of classification proposals for canine epilepsy have been published during the years reflecting always in parts the current proposals coming from the human epilepsy organisation the International League Against Epilepsy (ILAE). It has however not been possible to gain agreed consensus, "a common language", for the classification and terminology used between veterinary and human neurologists and neuroscientists, practitioners, neuropharmacologists and neuropathologists. This has led to an unfortunate situation where different veterinary publications and textbook chapters on epilepsy merely reflect individual author preferences with respect to terminology, which can be confusing to the readers and influence the definition and diagnosis of epilepsy in first line practice and research studies.In this document the International Veterinary Epilepsy Task Force (IVETF) discusses current understanding of canine epilepsy and presents our 2015 proposal for terminology and classification of epilepsy and epileptic seizures. We propose a classification system which reflects new thoughts from the human ILAE but also roots in former well accepted terminology. We think that this classification system can be used by all stakeholders. PMID:26316133

  11. Internal Dynamics and Boundary Forcing Characteristics Associated with Interannual Variability of the Asian Summer Monsoon

    NASA Technical Reports Server (NTRS)

    Lau, K.- M.; Kim, K.-M.; Yang, S.

    1998-01-01

    In this paper, we present a description of the internal dynamics and boundary forcing characteristics of two major components of the Asian summer monsoon (ASM), i.e., the South Asian (SAM) and the Southeast-East Asian monsoon (SEAM). The description is based on a new monsoon-climate paradigm in which the variability of ASM is considered as the outcome of the interplay of a "fast" and an "intermediate" monsoon subsystem, under the influenced of the "slow" varying external forcings. Two sets of regional monsoon indices derived from dynamically consistent rainfall and wind data are used in this study. For SAM, the internal dynamics is represented by that of a "classical" monsoon system where the anomalous circulation is governed by Rossby-wave dynamics, i.e., generation of anomalous vorticity induced by an off-equatorial heat source is balanced by planetary vorticity advection. On the other hand, the internal dynamics of SEAM is characterized by a "hybrid" monsoon system featuring multi-cellular meridional circulation over the East Asian section, extending from the deep tropics to midlatitudes. These meridional-cells link tropical heating to extratropical circulation system via the East Asian jetstream, and are responsible for the characteristic occurrences of zonally oriented anomalous rainfall patterns over East Asian and the subtropical western Pacific. In the extratropical regions, the major upper level vorticity balance is by anomalous vorticity advection and generation by the anomalous divergent circulation. A consequence of this is that compared to SAM, the SEAM is associated with stronger teleconnection patterns to regions outside the ASM. A strong SAM is linked to basin-scale sea surface temperature (SST) fluctuation with significant signal in the equatorial eastern Pacific. During the boreal spring SST warming in the Arabian Sea and the subtropical western Pacific may lead to a strong SAM. For SEAM, interannual variability is tied to SSTA over the Sea of

  12. All-Atom Internal Coordinate Mechanics (ICM) Force Field for Hexopyranoses and Glycoproteins

    PubMed Central

    2016-01-01

    We present an extension of the all-atom internal-coordinate force field, ICMFF, that allows for simulation of heterogeneous systems including hexopyranose saccharides and glycan chains in addition to proteins. A library of standard glycan geometries containing α- and β-anomers of the most common hexapyranoses, i.e., d-galactose, d-glucose, d-mannose, d-xylose, l-fucose, N-acetylglucosamine, N-acetylgalactosamine, sialic, and glucuronic acids, is created based on the analysis of the saccharide structures reported in the Cambridge Structural Database. The new force field parameters include molecular electrostatic potential-derived partial atomic charges and the torsional parameters derived from quantum mechanical data for a collection of minimal molecular fragments and related molecules. The ϕ/ψ torsional parameters for different types of glycosidic linkages are developed using model compounds containing the key atoms in the full carbohydrates, i.e., glycosidic-linked tetrahydropyran–cyclohexane dimers. Target data for parameter optimization include two-dimensional energy surfaces corresponding to the ϕ/ψ glycosidic dihedral angles in the disaccharide analogues, as determined by quantum mechanical MP2/6-31G** single-point energies on HF/6-31G** optimized structures. To achieve better agreement with the observed geometries of glycosidic linkages, the bond angles at the O-linkage atoms are added to the internal variable set and the corresponding bond bending energy term is parametrized using quantum mechanical data. The resulting force field is validated on glycan chains of 1–12 residues from a set of high-resolution X-ray glycoprotein structures based on heavy atom root-mean-square deviations of the lowest-energy glycan conformations generated by the biased probability Monte Carlo (BPMC) molecular mechanics simulations from the native structures. The appropriate BPMC distributions for monosaccharide–monosaccharide and protein–glycan linkages are derived

  13. Report of the International Society of Nephrology: North American Renal Disaster Response Task Force.

    PubMed

    Blake, Peter G; Parker, Thomas F

    2003-04-01

    This article comprises a report from the North American Renal Disaster Response Task Force (RDRTF) set up in 2001 by the International Society of Nephrology Acute Renal Failure Commission. The conclusions of the report are (1) given the rarity of renal disasters in the Americas the North American and Latin American RDRTF's should be merged; (2) for the same reason, a single RDRFT Coordination Center for the whole world should be established and it is suggested that this be in Ghent, Belgium; (3) the collaborative group set up in Europe and involving the European RDRTF and Medecins Sans Frontiers be asked to extend their rapid response service to cover acute renal disasters in the Americas south of the United States-Mexico border; (4) the combined RDRTF for the Americas should establish a list of nephrologists, nurses, and technicians who are available to assist in the acute response to renal disasters; (5) the combined RDRTF of the Americas establish an inventory of equipment, machines, and methods for their transport that would be available in the event of a disaster; and (6) the RDRTF of the Americas should undertake a large-scale educational initiative on management of renal disasters. PMID:12879370

  14. Comparative evaluation of bite forces in patients after treatment of mandibular fractures with miniplate osteosynthesis and internal locking miniplate osteosynthesis

    PubMed Central

    Kumar, Saurab; Gattumeedhi, Shashank Reddy; Sankhla, Bharat; Garg, Akshay; Ingle, Ekta; Dagli, Namrata

    2014-01-01

    Aims and Objectives: The aim of present study was to compare the stability of fractured mandibular fragments under functional load, when fixed with conventional miniplate and internal locking miniplate. Materials and Methods: Bite force (in kg) recorded in twenty mandible fractured patients and fifty normal healthy individuals. Bite force was measured at incisor and molar regions. Comparative evaluation of bite force generated was performed between 10 cases treated with conventional miniplates and 10 cases treated with internal locking miniplates. Bite force generated by patients in mandibular fracture between symphysis and the angle of mandible was recorded in incisor and molar regions preoperatively. The fracture fragments were fixed using the above fixation techniques. Then same recording was undertaken on the 7th, 14th, 21st, 28th, and 90th days postoperatively. Results: Bite force generated by patients treated with locking plates at the 7th, 14th, 21st, 28th, and 90th postoperative days was significantly higher as compared to those in patients treated with miniplates. Conclusion: It was observed in our study that the locking plate/screw system offers significant advantages over the conventional plating system. There are no intraoperative difficulties associated with placement of the plate. PMID:25452924

  15. International veterinary epilepsy task force consensus proposal: diagnostic approach to epilepsy in dogs.

    PubMed

    De Risio, Luisa; Bhatti, Sofie; Muñana, Karen; Penderis, Jacques; Stein, Veronika; Tipold, Andrea; Berendt, Mette; Farqhuar, Robyn; Fischer, Andrea; Long, Sam; Mandigers, Paul J J; Matiasek, Kaspar; Packer, Rowena M A; Pakozdy, Akos; Patterson, Ned; Platt, Simon; Podell, Michael; Potschka, Heidrun; Batlle, Martí Pumarola; Rusbridge, Clare; Volk, Holger A

    2015-01-01

    This article outlines the consensus proposal on diagnosis of epilepsy in dogs by the International Veterinary Epilepsy Task Force. The aim of this consensus proposal is to improve consistency in the diagnosis of epilepsy in the clinical and research settings. The diagnostic approach to the patient presenting with a history of suspected epileptic seizures incorporates two fundamental steps: to establish if the events the animal is demonstrating truly represent epileptic seizures and if so, to identify their underlying cause. Differentiation of epileptic seizures from other non-epileptic episodic paroxysmal events can be challenging. Criteria that can be used to make this differentiation are presented in detail and discussed. Criteria for the diagnosis of idiopathic epilepsy (IE) are described in a three-tier system. Tier I confidence level for the diagnosis of IE is based on a history of two or more unprovoked epileptic seizures occurring at least 24 h apart, age at epileptic seizure onset of between six months and six years, unremarkable inter-ictal physical and neurological examination, and no significant abnormalities on minimum data base blood tests and urinalysis. Tier II confidence level for the diagnosis of IE is based on the factors listed in tier I and unremarkable fasting and post-prandial bile acids, magnetic resonance imaging (MRI) of the brain (based on an epilepsy-specific brain MRI protocol) and cerebrospinal fluid (CSF) analysis. Tier III confidence level for the diagnosis of IE is based on the factors listed in tier I and II and identification of electroencephalographic abnormalities characteristic for seizure disorders. The authors recommend performing MRI of the brain and routine CSF analysis, after exclusion of reactive seizures, in dogs with age at epileptic seizure onset <6 months or >6 years, inter-ictal neurological abnormalities consistent with intracranial neurolocalisation, status epilepticus or cluster seizure at epileptic seizure onset

  16. Probing Membrane Order and Topography in Supported Lipid Bilayers by Combined Polarized Total Internal Reflection Fluorescence-Atomic Force Microscopy

    PubMed Central

    Oreopoulos, John; Yip, Christopher M.

    2009-01-01

    Determining the local structure, dynamics, and conformational requirements for protein-protein and protein-lipid interactions in membranes is critical to understanding biological processes ranging from signaling to the translocating and membranolytic action of antimicrobial peptides. We report here the application of a combined polarized total internal reflection fluorescence microscopy-in situ atomic force microscopy platform. This platform's ability to image membrane orientational order was demonstrated on DOPC/DSPC/cholesterol model membranes containing the fluorescent membrane probe, DiI-C20 or BODIPY-PC. Spatially resolved order parameters and fluorophore tilt angles extracted from the polarized total internal reflection fluorescence microscopy images were in good agreement with the topographical details resolved by in situ atomic force microscopy, portending use of this technique for high-resolution characterization of membrane domain structures and peptide-membrane interactions. PMID:19254557

  17. Forced and internal variability in temperature simulations and reconstructions of the Common Era

    NASA Astrophysics Data System (ADS)

    Fernández-Donado, Laura; Fidel González-Rouco, J.; Garcia-Bustamante, Elena; Smerdon, Jason S.; Luterbacher, Juerg; Raible, Christoph C.

    2016-04-01

    The relatively short ranges of external forcing variability within the CE represent a challenge in as much as the consistency between simulations and reconstructions can be affected by the large uncertainties in their respective responses to the external forcings. One of the core questions within this work relates therefore the extent to which a straight response to the external forcing can be identified during the period under study and whether this signal is common to simulated and reconstructed temperature. This study is based on an exhaustive compilation, analysis and intercomparison of the available hemispherical and global temperature reconstructions as well as a complete ensemble of simulations including both PMIP3/CMIP5 and non-PMIP3 model experiments. In addition, the various external forcing configurations applied to the models are characterized and a Total External Forcing, including all the individual forcing contributors, is developed for each experiment. Based on the linear relationship found at multidecadal and longer timescales during the last millennium between the temperature and the total external forcing, a quantitative metric of the ratio of response, the so-called Last Millennium Transient Climate Response (LMTCR), is obtained and compared for simulations and reconstructions. Within the LMTCR context, a significant quantitative consistency between the simulations and reconstructions is addressed. This work also offers a discussion about the impact that a range of generally accepted methodological approaches might have on the reconstructed ensemble uncertainties and their influences on model-data comparison exercises. A segregation among the various existing spatial targets within the NH, based on the different level of temperatura variability observed in the series, suggests a lower level of model-data consistency during the MCA than previously reported.

  18. International Education: A Force for Peace and Cross-Cultural Understanding?

    ERIC Educational Resources Information Center

    Brown, Lorraine

    2009-01-01

    This paper discusses the notion that the international sojourn has the potential to transform sojourners into cultural mediators who carry the power to improve global relations. A year-long ethnographic study of the adjustment experiences of international postgraduate students in England revealed a universal early enthusiasm for cross-cultural…

  19. Guidelines and Ethical Considerations for Assessment Center Operations: International Task Force on Assessment Center Guidelines.

    ERIC Educational Resources Information Center

    Public Personnel Management, 2000

    2000-01-01

    This update of the International Personnel Management Association's guidelines for organizational psychologists, human resource management specialists, and others addresses elements of assessment centers, policy statements, assessor training, informed participation, and participants' rights. (SK)

  20. The welfare effects of labour force growth with internationally mobile capital.

    PubMed

    Clarke, H R

    1994-02-01

    "This paper examines some economic effects of population growth, due to natural increase and immigration.... An objective is to assess how immigration and natural labour supply growth impact on international equilibrium when trade in produced inputs is induced by population changes. For the most part our analysis is based on theories on international factor mobility.... Natural population growth will be analysed as a byproduct of the factor mobility studies." PMID:12287550

  1. 77 FR 29899 - Safety Zone; International Special Operations Forces Week Capability Exercise, Seddon Channel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... Week Capability Exercise, Seddon Channel, Tampa, FL AGENCY: Coast Guard, DHS. ACTION: Temporary final... Operations Forces Week Capability Exercise. The exercise is scheduled to take place on Tuesday, May 22, 2012... associated with airborne and waterborne activities occurring during the exercise. Persons and vessels...

  2. The Peaceful Uses of Military Forces. Praeger Special Studies in International Politics and Public Affairs.

    ERIC Educational Resources Information Center

    Hanning, Hugh

    This study of the peaceful uses of military forces (PUMF) offers a compendium of information and principles for the planning and conduct of such PUMF activities as meeting disaster or emergency relief situations, education and training, and economic and social projects. The provision of training opportunities by the military is a means of…

  3. Theoretical Model of Drag Force Impact on a Model International Space Station (ISS) Satellite due to Solar Activity

    NASA Astrophysics Data System (ADS)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip Kumar

    The International Space Station (ISS) is the single largest and most complex scientific and engineering space structure in human history. Its orbital parameters make it extremely vulnerable to severe atmospheric drag force. Complex interactions between solar energetic particles, ultraviolet (UV) radiation with atmosphere and geomagnetic field cause heating and subsequent expansion of the upper atmosphere. This condition increases drag on low Earth orbit satellites (LEOSs) and varies with current space weather conditions. In this work, we apply the NRLMSISE-00 empirical atmospheric density model, as a function of space environmental parameters, to model drag force impact on a model LEOS during variation of solar activity. Applying the resulting drag model on a model ISS satellite we observe that depending on the severity and/or stage of solar activity or cycle, a massive artificial satellite could experience orbit decay rate of up to 2.95km/month during solar maximum and up to 1km/month during solar minimum.

  4. Effects of neutrals on internal forces and thermal conduction of a plasma in a magnetic field

    NASA Astrophysics Data System (ADS)

    Hirano, K.

    1984-08-01

    Using the Chapman-Enskog approximation the Boltzmann equation was solved to obtain friction and thermal forces appearing between ions and their parent atoms remaining in a plasma. The heat fluxes due to thermal conduction through ions and atoms were also evaluated. Charge transfer and the elastic scattering assuming the Sutherland potential were adopted as the basic collision process between ions and atoms. It was demonstrated that thermal force on neutrals always pushes them toward higher temperature region across a strong magnetic field but colder place along the field lines if the temperature is higher than 25 eV. A very small amount of neutrals, e.g., 1 ppm to the ion density, is found to be enough for neutrals transfering even much larger heat flux than the one by ion thermal conduction loss at a fusion temperature.

  5. The Role of Forcing and Internal Dynamics in explaining the 'Medieval Climate Anomaly'

    NASA Technical Reports Server (NTRS)

    Goossee, Hugues; Crespin, Elisabeth; Dubinkina, Svetlana; Loutre, Marie-France; Mann, Michael E.; Renssen, Hans; Shindell, Drew

    2012-01-01

    Proxy reconstructions suggest that peak global temperature during the past warm interval known as the Medieval Climate Anomaly (MCA, roughly 950-1250 AD) has been exceeded only during the most recent decades. To better understand the origin of this warm period, we use model simulations constrained by data assimilation establishing the spatial pattern of temperature changes that is most consistent with forcing estimates, model physics and the empirical information contained in paleoclimate proxy records. These numerical experiments demonstrate that the reconstructed spatial temperature pattern of the MCA can be explained by a simple thermodynamical response of the climate system to relatively weak changes in radiative forcing combined with a modification of the atmospheric circulation, displaying some similarities with the positive phase of the so-called Arctic Oscillation, and with northward shifts in the position of the Gulf Stream and Kuroshio currents. The mechanisms underlying the MCA are thus quite different from anthropogenic mechanisms responsible for modern global warming.

  6. Turbofan forced mixer-nozzle internal flowfield. Volume 2: Computational fluid dynamic predictions

    NASA Technical Reports Server (NTRS)

    Werle, M. J.; Vasta, V. N.

    1982-01-01

    A general program was conducted to develop and assess a computational method for predicting the flow properties in a turbofan forced mixed duct. The detail assessment of the resulting computer code is presented. It was found that the code provided excellent predictions of the kinematics of the mixing process throughout the entire length of the mixer nozzle. The thermal mixing process between the hot core and cold fan flows was found to be well represented in the low speed portion of the flowfield.

  7. Joining forces: Collaborating internationally to deliver high-quality, online postgraduate education in pain management

    PubMed Central

    Devonshire, Elizabeth; Siddall, Philip J

    2011-01-01

    The effective management of pain is a complex and costly global issue, requiring a range of innovative educational strategies to enable culturally appropriate and high-quality health care provision. In response to this issue, the Pain Management Research Institute at the University of Sydney (Sydney, Australia) has established several strategic alliances with other overseas universities to deliver online postgraduate education in pain management. The present article discusses the rationale for joining forces, and the approach adopted in creating and maintaining these alliances. It also provides insights into the benefits, challenges and opportunities associated with collaborative educational initiatives of this nature, from institutional, academic and student perspectives. PMID:22184549

  8. Joining forces: collaborating internationally to deliver high-quality, online postgraduate education in pain management.

    PubMed

    Devonshire, Elizabeth; Siddall, Philip

    2011-01-01

    The effective management of pain is a complex and costly global issue, requiring a range of innovative educational strategies to enable culturally appropriate and high-quality health care provision. In response to this issue, the Pain Management Research Institute at the University of Sydney (Sydney, Australia) has established several strategic alliances with other overseas universities to deliver online postgraduate education in pain management. The present article discusses the rationale for joining forces, and the approach adopted in creating and maintaining these alliances. It also provides insights into the benefits, challenges and opportunities associated with collaborative educational initiatives of this nature, from institutional, academic and student perspectives. PMID:22184549

  9. Turbofan forced mixer-nozzle internal flowfield. Volume 1: A benchmark experimental study

    NASA Technical Reports Server (NTRS)

    Paterson, R. W.

    1982-01-01

    An experimental investigation of the flow field within a model turbofan forced mixer nozzle is described. Velocity and thermodynamic state variable data for use in assessing the accuracy and assisting the further development of computational procedures for predicting the flow field within mixer nozzles are provided. Velocity and temperature data suggested that the nozzle mixing process was dominated by circulations (secondary flows) of a length scale on the order the lobe dimensions which were associated with strong radial velocities observed near the lobe exit plane. The 'benchmark' model mixer experiment conducted for code assessment purposes is discussed.

  10. Quasi-ellipsoidal heads to ASME Code under internal pressure stress analysis by the Force Method

    SciTech Connect

    Guedes, E.

    1996-12-01

    Torispherically-dished pressure vessel heads that meet Section VIII of the ASME Code can be completely analyzed by means of the so-called Force Method. Thus combined normal stresses (pressure plus radial growth plus bending) at the shell junctures that make up those heads may be determined to a good degree of accuracy, along with the ideal bending-free location of the welding line (circumferential joint that connects head to shell). As a useful consequence, head skirt is kept to a safe minimum.

  11. Surface electromyography activity of the rectus abdominis, internal oblique, and external oblique muscles during forced expiration in healthy adults.

    PubMed

    Ito, Kenichi; Nonaka, Koji; Ogaya, Shinya; Ogi, Atsushi; Matsunaka, Chiaki; Horie, Jun

    2016-06-01

    We aimed to characterize rectus abdominis, internal oblique, and external oblique muscle activity in healthy adults under expiratory resistance using surface electromyography. We randomly assigned 42 healthy adult subjects to 3 groups: 30%, 20%, and 10% maximal expiratory intraoral pressure (PEmax). After measuring 100% PEmax and muscle activity during 100% PEmax, the activity and maximum voluntary contraction of each muscle during the assigned experimental condition were measured. At 100% PEmax, the external oblique (p<0.01) and internal oblique (p<0.01) showed significantly elevated activity compared with the rectus abdominis muscle. Furthermore, at 20% and 30% PEmax, the external oblique (p<0.05 and<0.01, respectively) and the internal oblique (p<0.05 and<0.01, respectively) showed significantly elevated activity compared with the rectus abdominis muscle. At 10% PEmax, no significant differences were observed in muscle activity. Although we observed no significant difference between 10% and 20% PEmax, activity during 30% PEmax was significantly greater than during 20% PEmax (external oblique: p<0.05; internal oblique: p<0.01). The abdominal oblique muscles are the most active during forced expiration. Moreover, 30% PEmax is the minimum intensity required to achieve significant, albeit very slight, muscle activity during expiratory resistance. PMID:27077819

  12. Forces Affecting the Improvement and Implementation of International Perspectives in Secondary Level Agricultural Programs in Texas. A Summary Report of Research. Department Information Bulletin 99-2.

    ERIC Educational Resources Information Center

    Bell, Larry G.

    A study analyzed the forces affecting improvement and implementation of international agricultural perspectives in secondary programs of agricultural science in Texas. A mail survey, based on force-field analysis, was used to determine the effect of 14 variables, including 3 that involved perceptions of the relevance, knowledge, and implementation…

  13. Report of a workshop on nuclear forces and nonproliferation Woodrow Wilson international center for scholars, Washington, DC October 28, 2010

    SciTech Connect

    Pilat, Joseph F

    2010-12-08

    A workshop sponsored by the Los Alamos National Laboratory in cooperation with the Woodrow Wilson International Center for Scholars was held at the Wilson Center in Washington, DC, on October 28, 2010. The workshop addressed evolving nuclear forces and their impacts on nonproliferation in the context of the new strategic environment, the Obama Administration's Nuclear Posture Review and the 2010 NPT Review Conference. The discussions reflected the importance of the NPR for defining the role of US nuclear forces in dealing with 21st century threats and providing guidance for National Nuclear Security Administration (NNSA) and Department of Defense (DoD) programs and, for many but not all participants, highlighted its role in the successful outcome of the NPT RevCon. There was widespread support for the NPR and its role in developing the foundations for a sustainable nuclear-weapon program that addresses nuclear weapons, infrastructure and expertise in the broader nonproliferation, disarmament and international security contexts. However, some participants raised concerns about its implementation and its long-term effectiveness and sustainability.

  14. Semi-decentralized adaptive fuzzy control for cooperative multirobot systems with H(infinity) motion/internal force tracking performance.

    PubMed

    Lian, Kuang-Yow; Chiu, Chian-Song; Liu, P

    2002-01-01

    We present a semi-decentralized adaptive fuzzy control scheme for cooperative multirobot systems to achieve H(infinity) performance in motion and internal force tracking. First, we reformulate the overall system dynamics into a fully actuated system with constraints. To cope with both parametric and nonparametric uncertainties, the controller for each robot consists of two parts: 1) model-based adaptive controller; and 2) adaptive fuzzy logic controller (FLC). The model-based adaptive controller handles the nominal dynamics which results in both zero motion and internal force errors for a pure parametric uncertain system. The FLC part handles the unstructured dynamics and external disturbances. An H(infinity) tracking problem defined by a novel performance criterion is given and solved in the sequel. Hence, a robust controller satisfying the disturbance attenuation is derived being simple and singularity-free. Asymptotic convergence is obtained when the fuzzy approximation error is bounded with finite energy. Maintaining the same results, the proposed controller is further simplified for easier implementation. Finally, the numerical simulation results for two cooperative planar robots transporting an object illustrate the expected performance. PMID:18238126

  15. External push and internal pull forces recruit curvature sensing N-BAR domain proteins to the plasma membrane

    PubMed Central

    Galic, Milos; Jeong, Sangmoo; Tsai, Feng-Chiao; Joubert, Lydia-Marie; Wu, Yi I.; Hahn, Klaus M.; Cui, Yi; Meyer, Tobias

    2012-01-01

    Many of the more than 20 mammalian proteins with N-BAR domains1-2 control cell architecture3 and endocytosis4-5 by associating with curved sections of the plasma membrane (PM)6. It is not well understood whether N-BAR proteins are recruited directly by processes that mechanically curve the PM or indirectly by PM-associated adaptor proteins that recruit proteins with N-BAR domains that then induce membrane curvature. Here, we show that externally-induced inward deformation of the PM by cone-shaped nanostructures (Nanocones) and internally-induced inward deformation by contracting actin cables both trigger recruitment of isolated N-BAR domains to the curved PM. Markedly, live-cell imaging in adherent cells showed selective recruitment of full length N-BAR proteins and isolated N-BAR domains to PM sub-regions above Nanocone stripes. Electron microscopy confirmed that N-BAR domains are recruited to local membrane sites curved by Nanocones. We further showed that N-BAR domains are periodically recruited to curved PM sites during local lamellipodia retraction in the front of migrating cells. Recruitment required Myosin II-generated force applied to PM connected actin cables. Together, our study shows that N-BAR domains can be directly recruited to the PM by external push or internal pull forces that locally curve the PM. PMID:22750946

  16. Dependence of the climate prediction skill on spatiotemporal scales: Internal versus radiatively-forced contribution

    NASA Astrophysics Data System (ADS)

    Volpi, D.; Doblas-Reyes, F. J.; GarcíA-Serrano, J.; Guemas, V.

    2013-06-01

    This article aims at quantifying the improvement in climate prediction skill as a function of temporal (from monthly to decadal) and spatial scales (from grid point to global) when initializing a perturbed parameter ensemble of the Hadley Centre Climate Model. The focus is on near-surface temperature and precipitation in the Tropical band, the Northern and Southern hemispheres. For temperature, the forecast system reproduces the dominant impact of the external forcing at global spatial scale and at decadal time scales. There are significant improvements with initialization for the first 40 forecast months in the global and tropical domains. In the Northern (Southern) hemisphere, the initialization increases the skill in the first 12 (20) months on regional but not hemispheric scales. The initialization has a stronger impact in the model variants with a weaker global-mean temperature trend. For precipitation, the initialization corrects the negative correlation found at global and tropical scales.

  17. g-force induced giant efficiency of nanoparticles internalization into living cells.

    PubMed

    Ocampo, Sandra M; Rodriguez, Vanessa; de la Cueva, Leonor; Salas, Gorka; Carrascosa, Jose L; Rodríguez, María Josefa; García-Romero, Noemí; Cuñado, Jose Luis F; Camarero, Julio; Miranda, Rodolfo; Belda-Iniesta, Cristobal; Ayuso-Sacido, Angel

    2015-01-01

    Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparticles (IONPs)-labelled cells is one of the most promising approaches for a fast and reliable evaluation of grafted cells in both preclinical studies and clinical trials. Current procedures to label living cells with IONPs are based on direct incubation or physical approaches based on magnetic or electrical fields, which always display very low cellular uptake efficiencies. Here we show that centrifugation-mediated internalization (CMI) promotes a high uptake of IONPs in glioblastoma tumour cells, just in a few minutes, and via clathrin-independent endocytosis pathway. CMI results in controllable cellular uptake efficiencies at least three orders of magnitude larger than current procedures. Similar trends are found in human mesenchymal stem cells, thereby demonstrating the general feasibility of the methodology, which is easily transferable to any laboratory with great potential for the development of improved biomedical applications. PMID:26477718

  18. g-force induced giant efficiency of nanoparticles internalization into living cells

    PubMed Central

    Ocampo, Sandra M.; Rodriguez, Vanessa; de la Cueva, Leonor; Salas, Gorka; Carrascosa, Jose. L.; Josefa Rodríguez, María; García-Romero, Noemí; Luis, Jose; Cuñado, F.; Camarero, Julio; Miranda, Rodolfo; Belda-Iniesta, Cristobal; Ayuso-Sacido, Angel

    2015-01-01

    Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparticles (IONPs)-labelled cells is one of the most promising approaches for a fast and reliable evaluation of grafted cells in both preclinical studies and clinical trials. Current procedures to label living cells with IONPs are based on direct incubation or physical approaches based on magnetic or electrical fields, which always display very low cellular uptake efficiencies. Here we show that centrifugation-mediated internalization (CMI) promotes a high uptake of IONPs in glioblastoma tumour cells, just in a few minutes, and via clathrin-independent endocytosis pathway. CMI results in controllable cellular uptake efficiencies at least three orders of magnitude larger than current procedures. Similar trends are found in human mesenchymal stem cells, thereby demonstrating the general feasibility of the methodology, which is easily transferable to any laboratory with great potential for the development of improved biomedical applications. PMID:26477718

  19. g-force induced giant efficiency of nanoparticles internalization into living cells

    NASA Astrophysics Data System (ADS)

    Ocampo, Sandra M.; Rodriguez, Vanessa; de La Cueva, Leonor; Salas, Gorka; Carrascosa, Jose. L.; Josefa Rodríguez, María; García-Romero, Noemí; Luis, Jose; Cuñado, F.; Camarero, Julio; Miranda, Rodolfo; Belda-Iniesta, Cristobal; Ayuso-Sacido, Angel

    2015-10-01

    Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparticles (IONPs)-labelled cells is one of the most promising approaches for a fast and reliable evaluation of grafted cells in both preclinical studies and clinical trials. Current procedures to label living cells with IONPs are based on direct incubation or physical approaches based on magnetic or electrical fields, which always display very low cellular uptake efficiencies. Here we show that centrifugation-mediated internalization (CMI) promotes a high uptake of IONPs in glioblastoma tumour cells, just in a few minutes, and via clathrin-independent endocytosis pathway. CMI results in controllable cellular uptake efficiencies at least three orders of magnitude larger than current procedures. Similar trends are found in human mesenchymal stem cells, thereby demonstrating the general feasibility of the methodology, which is easily transferable to any laboratory with great potential for the development of improved biomedical applications.

  20. Internal Variability Versus Anthropogenic Forcing on Sea Level and Its Components

    NASA Astrophysics Data System (ADS)

    Marcos, Marta; Marzeion, Ben; Dangendorf, Sönke; Slangen, Aimée B. A.; Palanisamy, Hindumathi; Fenoglio-Marc, Luciana

    2016-05-01

    In this paper we review and update detection and attribution studies in sea level and its major contributors during the past decades. Tide gauge records reveal that the observed twentieth-century global and regional sea level rise is out of the bounds of its natural variability, evidencing thus a human fingerprint in the reported trends. The signal varies regionally, and it partly depends on the magnitude of the background variability. The human fingerprint is also manifested in the contributors of sea level for which observations are available, namely ocean thermal expansion and glaciers' mass loss, which dominated the global sea level rise over the twentieth century. Attribution studies provide evidence that the trends in both components are clearly dominated by anthropogenic forcing over the second half of the twentieth century. In the earlier decades, there is a lack of observations hampering an improved attribution of causes to the observed sea level rise. At certain locations along the coast, the human influence is exacerbated by local coastal activities that induce land subsidence and increase the risk of sea level-related hazards.

  1. Treating rheumatoid arthritis to target: recommendations of an international task force

    PubMed Central

    Smolen, Josef S; Aletaha, Daniel; Bijlsma, Johannes W J; Breedveld, Ferdinand C; Boumpas, Dimitrios; Burmester, Gerd; Combe, Bernard; Cutolo, Maurizio; de Wit, Maarten; Dougados, Maxime; Emery, Paul; Gibofsky, Alan; Gomez-Reino, Juan Jesus; Haraoui, Boulos; Kalden, Joachim; Keystone, Edward C; Kvien, Tore K; McInnes, Iain; Martin-Mola, Emilio; Montecucco, Carlomaurizio; Schoels, Monika; van der Heijde, Desirée

    2010-01-01

    Background Aiming at therapeutic targets has reduced the risk of organ failure in many diseases such as diabetes or hypertension. Such targets have not been defined for rheumatoid arthritis (RA). Objective To develop recommendations for achieving optimal therapeutic outcomes in RA. Methods A task force of rheumatologists and a patient developed a set of recommendations on the basis of evidence derived from a systematic literature review and expert opinion; these were subsequently discussed, amended and voted upon by >60 experts from various regions of the world in a Delphi-like procedure. Levels of evidence, strength of recommendations and levels of agreement were derived. Results The treat-to-target activity resulted in 10 recommendations. The treatment aim was defined as remission with low disease activity being an alternative goal in patients with long-standing disease. Regular follow-up (every 1–3 months during active disease) with appropriate therapeutic adaptation to reach the desired state within 3 to a maximum of 6 months was recommended. Follow-up examinations ought to employ composite measures of disease activity which include joint counts. Additional items provide further details for particular aspects of the disease. Levels of agreement were very high for many of these recommendations (≥9/10). Conclusion The 10 recommendations are supposed to inform patients, rheumatologists and other stakeholders about strategies to reach optimal outcomes of RA based on evidence and expert opinion. PMID:20215140

  2. Driving force transmission mechanism using a timing belt for an internal combustion engine

    SciTech Connect

    Abe, S.

    1987-11-24

    A driving force transmission mechanism is described comprising: a timing pulley having teeth, each of the teeth having a width perpendicular to a direction of movement of the teeth; and a timing belt engaging the timing pulley, the timing belt having teeth, each of the timing belt teeth having a width perpendicular to a direction of movement of the timing belt teeth; a width of the timing belt not being larger that a width of the timing pulley; the width of the teeth of the timing belt at dedendums of the teeth being larger than a width of engagement of the teeth of the timing belt with the teeth of the timing pulley; at least one of width end portions of the teeth of the timing pulley and width end portions of the teeth of the timing belt being cut out so that width end portions of the teeth of the timing belt at dedendums of the timing belt do not contact the teeth of the timing pulley.

  3. International confederation for cleft lip and palate and related craniofacial anomalies task force report: beyond eurocleft.

    PubMed

    Semb, Gunvor

    2014-11-01

    The assigned objective for the Task Force Beyond Eurocleft was "to make recommendations for initiations of local and/or participation in multi-national cleft outcome studies and consist of individuals from the European experience with cleft outcome studies (Scandcleft, Eurocleft) and those who have initiated, or intend to initiate, similar studies in other geographical areas." By May 2013 the Task Force (TF) consisted of 183 members from 59 countries. It was agreed that this initiative should be truly global and include all cleft specialties as well as representatives from cleft support groups in recognition of the huge commitment for improving cleft care worldwide. The vision for this group is to build a dynamic, well-functioning TF that will work globally and be multidisciplinary with inclusive and respectful behavior to improve care for all individuals born with cleft lip and/or palate. As there is a large diversity in needs and interest in the group a range of parallel approaches would be required depending on the experience, resources, and challenges of regions, teams, and individuals. Important ideas for future work were: (1) Work on a global survey of access, existing outcome studies, current collaborations, and lessons learned. (2) Work towards the creation of a lasting, living resource for newcomers to intercenter collaboration that is kept fresh with new reports, copies of relevant publications, model grant applications, and a list of volunteers with the right experience to provide support and guidance for new initiatives. (3) Develop simple online training modules to provide information about the benefits and principles of multidisciplinary care, collaborative data collection and auditing short and longer-term outcomes. (4) Establish subgroups that will work within all regions of the world with regional and national leaders identified. An evaluation of current standards of care should be undertaken and country/region specific remedies to optimize

  4. International Literacy Year 1990: Building the Momentum. Report of the Meeting of the International Task Force on Literacy (2nd, West Berlin, Federal Republic of Germany, June 5-10, 1988).

    ERIC Educational Resources Information Center

    Marshall, Judith

    This report provides materials from the second meeting of the International Task Force on Literacy (ITFL), which focused on specific goals and targets for nongovernmental organization (NGO) mobilization for 1990, International Literacy Year (ILY). Section 2 discusses issues that emerged as central to work in literacy, including literacy,…

  5. Treating rheumatoid arthritis to target: 2014 update of the recommendations of an international task force

    PubMed Central

    Smolen, Josef S; Breedveld, Ferdinand C; Burmester, Gerd R; Bykerk, Vivian; Dougados, Maxime; Emery, Paul; Kvien, Tore K; Navarro-Compán, M Victoria; Oliver, Susan; Schoels, Monika; Scholte-Voshaar, Marieke; Stamm, Tanja; Stoffer, Michaela; Takeuchi, Tsutomu; Aletaha, Daniel; Andreu, Jose Louis; Aringer, Martin; Bergman, Martin; Betteridge, Neil; Bijlsma, Hans; Burkhardt, Harald; Combe, Bernard; Durez, Patrick; Fonseca, Joao Eurico; Gibofsky, Alan; Gomez-Reino, Juan J; Graninger, Winfried; Hannonen, Pekka; Haraoui, Boulos; Kouloumas, Marios; Landewe, Robert; Martin-Mola, Emilio; Nash, Peter; Ostergaard, Mikkel; Östör, Andrew; Richards, Pam; Sokka-Isler, Tuulikki; Thorne, Carter; Tzioufas, Athanasios G; van Vollenhoven, Ronald; de Wit, Martinus

    2016-01-01

    Background Reaching the therapeutic target of remission or low-disease activity has improved outcomes in patients with rheumatoid arthritis (RA) significantly. The treat-to-target recommendations, formulated in 2010, have provided a basis for implementation of a strategic approach towards this therapeutic goal in routine clinical practice, but these recommendations need to be re-evaluated for appropriateness and practicability in the light of new insights. Objective To update the 2010 treat-to-target recommendations based on systematic literature reviews (SLR) and expert opinion. Methods A task force of rheumatologists, patients and a nurse specialist assessed the SLR results and evaluated the individual items of the 2010 recommendations accordingly, reformulating many of the items. These were subsequently discussed, amended and voted upon by >40 experts, including 5 patients, from various regions of the world. Levels of evidence, strengths of recommendations and levels of agreement were derived. Results The update resulted in 4 overarching principles and 10 recommendations. The previous recommendations were partly adapted and their order changed as deemed appropriate in terms of importance in the view of the experts. The SLR had now provided also data for the effectiveness of targeting low-disease activity or remission in established rather than only early disease. The role of comorbidities, including their potential to preclude treatment intensification, was highlighted more strongly than before. The treatment aim was again defined as remission with low-disease activity being an alternative goal especially in patients with long-standing disease. Regular follow-up (every 1–3 months during active disease) with according therapeutic adaptations to reach the desired state was recommended. Follow-up examinations ought to employ composite measures of disease activity that include joint counts. Additional items provide further details for particular aspects of the

  6. Report of a Workshop in Nuclear Forces and Nonproliferation held at the Woodrow Wilson International Center for Scholars, Washington, DC

    SciTech Connect

    Pilat, Joseph F

    2009-01-01

    The workshop addressed evolving nuclear forces and their impacts on nonproliferation in the context of the new strategic environment, the Obama Administration's Nuclear Posture Review (NPR) Review and the 2010 Conference (RevCon) of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The issues discussed are at the heart of the debate on nuclear policy issues such asfuture nuclear weapons requirements and nonproliferation, but also the stockpile stewardship program and infrastructure modernization. The workshop discussions reflected the importance of the NPRfor defining the role of US nuclear forces in dealing with 21s1 century threats and providing guidance that will shape NNSA and DoD programs. They also highlighted its importancefor NPT diplomacy. The discussion noted the report of the bipartisan Congressional Commission on the Strategic Posture of the United States, and the expectation that the NPR would likely reflect its consensus to a large degree (although the Administration was not bound by the report). There was widespread support for developing thefoundationsfor a sustainable nuclear-weapon program that addresses nuclear weapons, infrastructure and expertise in the broader nonproliferation, disarmament and international security contexts. The discussion also revealed a convergence of views, but no consensus, on a number of important issues, including the diminished role but continued importance of nuclear weapons; the need to take action to ensure the sustainability of the stockpile, and the recapitalization of the infrastructure and expertise; and the need to take action to promote nonproliferation, arms control and disarmament objectives.

  7. Internally Displaced “Victims of Armed Conflict” in Colombia: The Trajectory and Trauma Signature of Forced Migration

    PubMed Central

    Shultz, James M.; Garfin, Dana Rose; Espinel, Zelde; Araya, Ricardo; Oquendo, Maria A.; Wainberg, Milton L.; Chaskel, Roberto; Gaviria, Silvia L.; Ordóñez, Anna E.; Espinola, Maria; Wilson, Fiona E.; García, Natalia Muñoz; Ceballos, Ángela Milena Gómez; Garcia-Barcena, Yanira; Verdeli, Helen; Neria, Yuval

    2016-01-01

    While conflict-induced forced migration is a global phenomenon, the situation in Colombia, South America, is distinctive. Colombia has ranked either first or second in the number of internally displaced persons for 10 years, a consequence of decades of armed conflict compounded by high prevalence of drug trafficking. The displacement trajectory for displaced persons in Colombia proceeds through a sequence of stages: (1) pre-expulsion threats and vulnerability, (2) expulsion, (3) migration, (4) initial adaptation to relocation, (5) protracted resettlement (the end point for most forced migrants), and, rarely, (6) return to the community of origin. Trauma signature analysis, an evidence-based method that elucidates the physical and psychological consequences associated with exposures to harm and loss during disasters and complex emergencies, was used to identify the psychological risk factors and potentially traumatic events experienced by conflict-displaced persons in Colombia, stratified across the phases of displacement. Trauma and loss are experienced differentially throughout the pathway of displacement. PMID:25135775

  8. PHARMACOLOGICAL INTERVENTIONS IN FRAILTY AND SARCOPENIA: REPORT BY THE INTERNATIONAL CONFERENCE ON FRAILTY AND SARCOPENIA RESEARCH TASK FORCE

    PubMed Central

    Cesari, M.; Fielding, R.; Bénichou, O.; Bernabei, R.; Bhasin, S.; Guralnik, J.M.; Jette, A.; Landi, F.; Pahor, M.; Rodriguez-Manas, L.; Rolland, Y.; Roubenoff, R.; Sinclair, A.J.; Studenski, S.; Travison, T.; Vellas, B.

    2015-01-01

    Sarcopenia and frailty often co-exist and both have physical function impairment as a core component. Yet despite the urgency of the problem, the development of pharmaceutical therapies for sarcopenia and frailty has lagged, in part because of the lack of consensus definitions for the two conditions. A task force of clinical and basic researchers, leaders from the pharmaceutical and nutritional industries, and representatives from non-profit organizations was established in 2012 with the aim of addressing specific issues affecting research and clinical activities on frailty and sarcopenia. The task force came together on April 22, 2015 in Boston, Massachusetts, prior to the International Conference on Frailty and Sarcopenia Research (ICFSR). The theme of this meeting was to discuss challenges related to drugs designed to target the biology of frailty and sarcopenia as well as more general questions about designing efficient drug trials for these conditions. The present article reports the results of the task force’s deliberations based on available evidence and preliminary results of ongoing activities. Overall, the lack of a consensus definition for sarcopenia and frailty was felt as still present and severely limiting advancements in the field. However, agreement appears to be emerging that low mass alone provides insufficient clinical relevance if not combined with muscle weakness and/or functional impairment. In the next future, it will be important to build consensus on clinically meaningful functional outcomes and test/validate them in long-term observational studies. PMID:26366378

  9. Eruption triggering of giant magma bodies by internal versus external forcing: A rhyolite-MELTS study

    NASA Astrophysics Data System (ADS)

    Carley, T. L.; Gualda, G. A.; Ghiorso, M. S.; Miller, C. F.

    2012-12-01

    Silicic volcanism, particularly supereruptions, raises questions about the mechanisms by which magma bodies destabilize and erupt. Are external events necessary to initiate an eruption of a large silicic system, or is possible for internal processes (crystallization, volatile exsolution) to destabilize a system and drive it to erupt? If external triggers are critically important to prompting eruption, are all felsic magma bodies equally prone to erupt? To respond to these questions, we use rhyolite-MELTS (Gualda et al. 2012) to investigate the pre-eruptive chemical evolution and the resultant changes to physical properties of giant (super-eruptive) felsic magma bodies. Simulations are conducted using pumice and glass compositions from the Peach Spring (Southwestern USA) and the Bishop (California USA) Tuffs, two giant high-silica rhyolite deposits. In our simulations, we vary initial pressure (150-350 MPa in 50 MPa intervals), volatile content (initial water ranging from 1-7 wt. %), mode of crystallization (equilibrium vs. fractional), and rheology of the magma reservoir (isobaric vs. isochoric vs. transitional). We run simulations through as much of the crystallization interval as possible, but focus on the first ~50 wt. % crystallization, most relevant for volcanic systems. In all simulations, we observe near-invariant behavior when the system becomes saturated in quartz, two feldspars and a fluid phase, from which point crystallization is essentially isothermal. Prior to the near-invariant, crystallization leads to gradual changes in bulk properties (e.g., < 1% volume decrease over 50 °C), which effectively results in modest pressure changes within the magma body (i.e., ~10 MPa). Upon reaching the near-invariant, the bulk properties change abruptly (e.g., > 5% volume increase in 0.1 °C), causing significant overpressurization of the magma body. The magnitude of this overpressurization (i.e. 10s to 100s of MPa depending on system conditions) is sufficient to

  10. PREFACE: NC-AFM 2004: Proceedings of the 7th International Conference on Non-contact Atomic Force Microscopy

    NASA Astrophysics Data System (ADS)

    Schwarz, Udo

    2005-03-01

    With the ongoing miniaturization of devices and controlled nanostructuring of materials, the importance of atomic-scale information on surfaces and surface properties is growing continuously. The astonishing progress in nanoscience and nanotechnology that took place during the last two decades was in many ways related to recent progress in high-resolution imaging techniques such as scanning tunnelling microscopy and transmission electron microscopy. Since the mid-1990s, non-contact atomic force microscopy (NC-AFM) performed in ultrahigh vacuum has evolved as an alternative technique that achieves atomic resolution, but without the restriction to conducting surfaces of the previously established techniques. Advances of the rapidly developing field of NC-AFM are discussed at annual conferences as part of a series that started in 1998 in Osaka, Japan. This special issue of Nanotechnology is a compilation of original work presented at the 7th International Conference on Non-contact Atomic Force Microscopy that took place in Seattle, USA, 12-15 September 2004. Over the years, the conference grew in size and scope. Atomic resolution imaging of oxides and semiconductors remains an issue. Noticeable new developments have been presented in this regard such as, e.g., the demonstrated ability to manipulate individual atoms. Additionally, the investigation of individual molecules, clusters, and organic materials gains more and more attention. In this context, considerable effort is undertaken to transfer the NC-AFM principle based on frequency modulation to applications in air and liquids with the goal of enabling high-resolution surface studies of biological material in native environments, as well as to reduce the experimental complexity, which so far involves the availability of (costly) vacuum systems. Force spectroscopy methods continue to be improved and are applied to topics such as the imaging of the three-dimensional force field as a function of the distance with

  11. Dynamic fe Model of Sitting Man Adjustable to Body Height, Body Mass and Posture Used for Calculating Internal Forces in the Lumbar Vertebral Disks

    NASA Astrophysics Data System (ADS)

    Pankoke, S.; Buck, B.; Woelfel, H. P.

    1998-08-01

    Long-term whole-body vibrations can cause degeneration of the lumbar spine. Therefore existing degeneration has to be assessed as well as industrial working places to prevent further damage. Hence, the mechanical stress in the lumbar spine—especially in the three lower vertebrae—has to be known. This stress can be expressed as internal forces. These internal forces cannot be evaluated experimentally, because force transducers cannot be implementated in the force lines because of ethical reasons. Thus it is necessary to calculate the internal forces with a dynamic mathematical model of sitting man.A two dimensional dynamic Finite Element model of sitting man is presented which allows calculation of these unknown internal forces. The model is based on an anatomic representation of the lower lumbar spine (L3-L5). This lumber spine model is incorporated into a dynamic model of the upper torso with neck, head and arms as well as a model of the body caudal to the lumbar spine with pelvis and legs. Additionally a simple dynamic representation of the viscera is used. All these parts are modelled as rigid bodies connected by linear stiffnesses. Energy dissipation is modelled by assigning modal damping ratio to the calculated undamped eigenvalues. Geometry and inertial properties of the model are determined according to human anatomy. Stiffnesses of the spine model are derived from static in-vitro experiments in references [1] and [2]. Remaining stiffness parameters and parameters for energy dissipation are determined by using parameter identification to fit measurements in reference [3]. The model, which is available in 3 different postures, allows one to adjust its parameters for body height and body mass to the values of the person for which internal forces have to be calculated.

  12. Development of a new physics-based internal coordinate mechanics force field (ICMFF) and its application to protein loop modeling

    PubMed Central

    Arnautova, Yelena A.; Abagyan, Ruben A.

    2010-01-01

    We report the development of ICMFF, new force field parameterized using a combination of experimental data for crystals of small molecules and quantum mechanics calculations. The main features of ICMFF include: (a) parameterization for the dielectric constant relevant to the condensed state (ε=2) instead of vacuum; (b) an improved description of hydrogen-bond interactions using duplicate sets of van der Waals parameters for heavy atom-hydrogen interactions; and (c) improved backbone covalent geometry and energetics achieved using novel backbone torsional potentials and inclusion of the bond angles at the Cα atoms into the internal variable set. The performance of ICMFF was evaluated through loop modeling simulations for 4-13 residue loops. ICMFF was combined with a solvent-accessible surface area solvation model optimized using a large set of loop decoys. Conformational sampling was carried out using the Biased Probability Monte Carlo method. Average/median backbone root-mean-square deviations of the lowest energy conformations from the native structures were 0.25/0.21 Å for 4 residues loops, 0.84/0.46 Å for 8 residue loops, and 1.16/0.73 Å for 12 residue loops. To our knowledge, these results are significantly better than or comparable to those reported to date for any loop modeling method that does not take crystal packing into account. Moreover, the accuracy of our method is on par with the best previously reported results obtained considering the crystal environment. We attribute this success to the high accuracy of the new ICM force field achieved by meticulous parameterization, to the optimized solvent model, and the efficiency of the search method. PMID:21069716

  13. Computation of the internal forces in cilia: application to ciliary motion, the effects of viscosity, and cilia interactions.

    PubMed

    Gueron, S; Levit-Gurevich, K

    1998-04-01

    This paper presents a simple and reasonable method for generating a phenomenological model of the internal mechanism of cilia. The model uses a relatively small number of parameters whose values can be obtained by fitting to ciliary beat shapes. Here, we use beat patterns observed in Paramecium. The forces that generate these beats are computed and fit to a simple functional form called the "engine." This engine is incorporated into a recently developed hydrodynamic model that accounts for interactions between neighboring cilia and between the cilia and the surface from which they emerge. The model results are compared to data on ciliary beat patterns of Paramecium obtained under conditions where the beats are two-dimensional. Many essential features of the motion, including several properties that are not built in explicitly, are shown to be captured. In particular, the model displays a realistic change in beat pattern and frequency in response to increased viscosity and to the presence of neighboring cilia in configurations such as rows of cilia and two-dimensional arrays of cilia. We found that when two adjacent model cilia start beating at different phases they become synchronized within several beat periods, as observed in experiments where two flagella are brought into close proximity. Furthermore, examination of various multiciliary configurations shows that an approximately antiplectic wave pattern evolves autonomously. This modeling evidence supports earlier conjectures that metachronism may occur, at least partially, as a self-organized phenomenon due to hydrodynamic interactions between neighboring cilia. PMID:9545031

  14. A total internal reflection ellipsometry and atomic force microscopy study of interactions between Proteus mirabilis lipopolysaccharides and antibodies.

    PubMed

    Gleńska-Olender, J; Sęk, S; Dworecki, K; Kaca, W

    2015-07-01

    Specific antigen-antibody interactions play a central role in the human immune system. The objective of this paper is to detect immune complexes using label-free detection techniques, that is, total internal reflection ellipsometry (TIRE) and atomic force microscopy (AFM)-based topography and recognition imaging. Interactions of purified rabbit immunoglobulin G (IgG) antibodies with bacterial endotoxins (Proteus mirabilis S1959 O3 lipopolysaccharides) were studied. Lipopolysaccharide was adsorbed on gold surface for TIRE. In the AFM imaging experiments, LPS was attachment to the PEG linker (AFM tip modification). The mica surface was covered by IgG. In TIRE, the optical parameters Ψ and Δ change when a complex is formed. It was found that even highly structured molecules, such as IgG antibodies (anti-O3 LPS rabbit serum), preserve their specific affinity to their antigens (LPS O3). LPS P. mirabilis O3 response of rabbit serum anti-O3 was also tested by topography and recognition imaging. Both TIRE and AFM techniques were recruited to check for possible detection of antigen-antibody recognition event. The presented data allow for determination of interactions between a variety of biomolecules. In future research, this technique has considerable potential for studying a wide range of antigen-antibody interactions and its use may be extended to other biomacromolecular systems. PMID:25854960

  15. Fast-track extreme event attribution: How fast can we disentangle thermodynamic (forced) and dynamic (internal) contributions?

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Otto, Friederike; Uhe, Peter; Allen, Myles; Cullen, Heidi

    2016-04-01

    Within the last decade, extreme weather event attribution has emerged as a new field of science and garnered increasing attention from the wider scientific community and the public. Numerous methods have been put forward to determine the contribution of anthropogenic climate change to individual extreme weather events. So far nearly all such analyses were done months after an event has happened. First, we present our newly established method which can assess the fraction of attributable risk (FAR) of a severe weather event due to an external driver in real-time. The method builds on a large ensemble of atmosphere-only GCM/RCM simulations forced by seasonal forecast sea surface temperatures (SSTs). Taking the UK 2013/14 winter floods as an example, we demonstrate that the change in risk for heavy rainfall during the England floods due to anthropogenic climate change is of similar magnitude using either observed or seasonal forecast SSTs. While FAR is assumed to be independent from event-specific dynamic contributions due to anomalous circulation patterns as a first approximation, the risk of an event to occur under current conditions is clearly a function of the state of the atmosphere. The shorter the event, the more it is a result of chaotic internal weather variability. Hence we are interested to (1) attribute the event to thermodynamic and dynamic causes and to (2) establish a sensible time-scale for which we can make a useful and potentially robust attribution statement with regard to event-specific dynamics. Having tested the dynamic response of our model to SST conditions in January 2014, we find that observed SSTs are required to establish a discernible link between anomalous ocean temperatures and the atmospheric circulation over the North Atlantic in general and the UK in particular. However, for extreme events occurring under strongly anomalous SST patterns, associated with known low-frequency climate modes such as El Nino or La Nina, forecast SSTs can

  16. A review of a method for dynamic load distribution, dynamical modeling, and explicit internal force control when two manipulators mutually lift and transport a rigid body object

    SciTech Connect

    Unseren, M.A.

    1997-04-20

    The paper reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restrict the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  17. PREFACE: NC-AFM 2006: Proceedings of the 9th International Conference on Non-contact Atomic Force Microscopy

    NASA Astrophysics Data System (ADS)

    Tomitori, Masahiko; Onishi, Hiroshi

    2007-02-01

    The advent of scanning probe microscopy (SPM) in the 1980s has significantly promoted nanoscience and nanotechnology. In particular, non-contact atomic force microscopy (NC-AFM), one of the SPM family, has unique capabilities with high spatial resolution for nanoscale measurements in vacuum, air and liquids. In the last decade we have witnessed the rapid progress of NC-AFM with improved performance and increasing applications. A series of NC-AFM international conferences have greatly contributed to this field. Initiated in Osaka in 1998, the NC-AFM meeting has been followed by annual conferences at Pontresina, Hamburg, Kyoto, Montreal, Dingle, Seattle and Bad Essen. The 9th conference was held in Kobe, Japan, 16-20 July 2006. This special issue of Nanotechnology contains the outstanding contributions of the conference. During the meeting delegates learnt about a number of significant advances. Topics covered atomic resolution imaging of metals, semiconductors, insulators, ionic crystals, oxides, molecular systems, imaging of biological materials in various environments and novel instrumentation. Work also included the characterization of electronic and magnetic properties, tip and cantilever fabrication and characterization, atomic distinction based on analysis of tip-sample interaction, atomic scale manipulation, fabrication of nanostructures using NC-AFM, and related theories and simulations. We are greatly impressed by the increasing number of applications, and convinced that NC-AFM and related techniques are building a bridge to a future nano world, where quantum phenomena will dominate and nano devices will be realized. In addition, a special session on SPM road maps was held as a first trial in the field, where the future prospects of SPM were discussed enthusiastically. The overall success of the NC-AFM 2006 conference was due to the efforts of many individuals and groups with respect to scientific and technological progress, as well as the international

  18. Assessment of forced and internal variability in the AMO through analyses of SST data from CMIP5 historical simulations and observations

    NASA Astrophysics Data System (ADS)

    Steinman, B. A.; Mann, M. E.; Miller, S. K.; Emanuel, K.

    2013-12-01

    The Atlantic Multidecadal Oscillation (AMO) is a mode of North Atlantic sea surface temperature (SST) variability that has substantial impacts on Northern Hemisphere precipitation and temperature patterns, as well as Atlantic hurricane activity. Climate models and paleoclimate data suggest that the warm AMO phase can enhance drought in the American mid- and southwest, increase rainfall intensity and amounts in North Eastern Brazil and the African Sahel region, and increase the number of severe Atlantic hurricanes. While models and instrumental data provide some support for the AMO as an internal climate ';oscillation', questions remain regarding the proportion of AMO variability resulting from internal and external forcing, and more specifically, how much of the recent (i.e. late 20th century) north Atlantic warming is anthropogenically forced. Several studies have addressed these issues and proposed various methods for diagnosing the AMO using historical climate model simulations (e.g. from CMIP3) and instrumental data. Here we present results from analyses of the North Atlantic region in historical simulations from Climate Model Intercomparison Project 5 (CMIP5). Our approach involves (1) analyzing a grand ensemble mean based on averaging realizations of all available models, such that random, internal variability components cancel and only a forced component remains; (2) for all models with at least four realizations, estimating a forced component by averaging multiple realizations and estimating internal variability components from the residual series of individual realizations and (3) analyzing control simulations for the corresponding models to assess whether or not there is evidence of enhanced AMO-like internal variability.

  19. PREFACE: NC-AFM 2005: Proceedings of the 8th International Conference on Non-Contact Atomic Force Microscopy

    NASA Astrophysics Data System (ADS)

    Reichling, M.; Mikosch, W.

    2006-04-01

    The 8th International Conference on Non-Contact Atomic Force Microscopy, held in Bad Essen, Germany, from 15 18th August 2005, attracted a record breaking number of participants presenting excellent contributions from a variety of scientific fields. This clearly demonstrated the high level of activity and innovation present in the community of NC-AFM researchers and the continuous growth of the field. The strongest ever participation of companies for a NC-AFM meeting is a sign for the emergence of new markets for the growing NC-AFM community; and the high standard of the products presented at the exhibition, many of them brand-new developments, reflected the unbroken progress in technology. The development of novel technologies and the sophistication of known techniques in research laboratories and their subsequent commercialization is still a major driving force for progress in this area of nanoscience. The conference was a perfect demonstration of how progress in the development of enabling technologies can readily be transcribed into basic research yielding fundamental insight with an impact across disciplines. The NC-AFM 2005 scientific programme was based on five cornerstones, each representing an area of vivid research and scientific progress. Atomic resolution imaging on oxide surfaces, which has long been a vision for the catalysis community, appears to be routine in several laboratories and after a period of demonstrative experiments NC-AFM now makes unique contributions to the understanding of processes in surface chemistry. These capabilities also open up new routes for the analysis of clusters and molecules deposited on dielectric surfaces where resolution limits are pushed towards the single atom level. Atomic precision manipulation with the dynamic AFM left the cradle of its infancy and flourishes in the family of bottom-up fabrication nanotechnologies. The systematic development of established and the introduction of new concepts of contrast

  20. A numerical simulation approach to studying anterior cruciate ligament strains and internal forces among young recreational women performing valgus inducing stop-jump activities.

    PubMed

    Kar, Julia; Quesada, Peter M

    2012-08-01

    Anterior cruciate ligament (ACL) injuries are commonly incurred by recreational and professional women athletes during non-contact jumping maneuvers in sports like basketball and volleyball, where incidences of ACL injury is more frequent to females compared to males. What remains a numerical challenge is in vivo calculation of ACL strain and internal force. This study investigated effects of increasing stop-jump height on neuromuscular and bio-mechanical properties of knee and ACL, when performed by young female recreational athletes. The underlying hypothesis is increasing stop-jump (platform) height increases knee valgus angles and external moments which also increases ACL strain and internal force. Using numerical analysis tools comprised of Inverse Kinematics, Computed Muscle Control and Forward Dynamics, a novel approach is presented for computing ACL strain and internal force based on (1) knee joint kinematics and (2) optimization of muscle activation, with ACL insertion into musculoskeletal model. Results showed increases in knee valgus external moments and angles with increasing stop-jump height. Increase in stop-jump height from 30 to 50 cm lead to increase in average peak valgus external moment from 40.5 ± 3.2 to 43.2 ± 3.7 Nm which was co-incidental with increase in average peak ACL strain, from 9.3 ± 3.1 to 13.7 ± 1.1%, and average peak ACL internal force, from 1056.1 ± 71.4 to 1165.4 ± 123.8 N for the right side with comparable increases in the left. In effect this study demonstrates a technique for estimating dynamic changes to knee and ACL variables by conducting musculoskeletal simulation on motion analysis data, collected from actual stop-jump tasks performed by young recreational women athletes. PMID:22527014

  1. Business and International Education. A Report Submitted by the Task Force on Business and International Education to Government/Academic Interface Committee. Occasional Paper No.4.

    ERIC Educational Resources Information Center

    American Council on Education, Washington, DC. International Education Project.

    A study was undertaken of the educational needs of present and future managers of the large number of business firms in the United States that are or will be affected by economic and political environments abroad. The task force concluded that most firms, regardless of size and type of operation, will be affected by economic and political…

  2. Policy and Practice Implications of the Program for International Student Assessment (PISA) 2000. Report of the International Reading Association PISA Task Force.

    ERIC Educational Resources Information Center

    Topping, Keith; Valtin, Renate; Roller, Cathy; Brozo, William; Dionisio, M. Lourdes

    The Program for International Student Assessment (PISA) is a study of comparisons. Subjects, 15-year-old students from 32 participating countries, were compared in their abilities to "use literacy knowledge and skills to meet real-life challenges," as assessed on a two-hour, paper-and-pencil test. Students also responded to a questionnaire related…

  3. Understanding the Programmatic and Contextual Forces That Influence Participation in a Government-Sponsored International Student-Mobility Program

    ERIC Educational Resources Information Center

    Perna, Laura W.; Orosz, Kata; Jumakulov, Zakir; Kishkentayeva, Marina; Ashirbekov, Adil

    2015-01-01

    Although prior research establishes the forces that "push" and "pull" students to participate in foreign study, the transferability of findings from earlier studies is limited by the absence of theoretical grounding. In addition, relatively little is known about how a government-sponsored student mobility program promotes…

  4. Speaker-External versus Speaker-Internal Forces on Utterance Form: Do Cognitive Demands Override Threats to Referential Success?

    ERIC Educational Resources Information Center

    Lane, Liane Wardlow; Ferreira, Victor S.

    2008-01-01

    To what extent do speaker-external communicative pressures versus speaker-internal cognitive pressures affect utterance form? Four experiments measured speakers' references to privately known (i.e., privileged) objects when naming mutually known (i.e., common ground) objects. Although speaker-external communicative pressures demanded that speakers…

  5. Can International Large-Scale Assessments Inform a Global Learning Goal? Insights from the Learning Metrics Task Force

    ERIC Educational Resources Information Center

    Winthrop, Rebecca; Simons, Kate Anderson

    2013-01-01

    In recent years, the global community has developed a range of initiatives to inform the post-2015 global development agenda. In the education community, International Large-Scale Assessments (ILSAs) have an important role to play in advancing a global shift in focus to access plus learning. However, there are a number of other assessment tools…

  6. High frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing

    NASA Astrophysics Data System (ADS)

    Liévana MacTavish, A.; Ladah, L. B.; Lavín, M. F.; Filonov, A.; Tapia, Fabian J.; Leichter, J.

    2016-04-01

    We related the vertical distribution and abundance of nearshore meroplankton at hourly time scales with internal tidal wave events. We proposed that significant changes in plankter abundance would occur across internal tidal fronts, and that surface and bottom strata would respond in opposite fashions. First-mode internal tidal bores propagating in the alongshore direction were detected in water-column currents and baroclinic temperature changes. Surface and bottom currents always flowed in opposite directions, and abrupt flow reversals coincided with large temperature changes during arrival of bores. Crab zoeae and barnacle cyprids were more abundant in the bottom strata, whereas barnacle nauplii showed the opposite pattern. Significant changes in vertical distribution and abundance of target meroplankters occurred across internal tidal fronts, especially for crabs at depth, with surface and bottom organisms responding in opposite fashions. Changes in plankter abundance were significantly correlated with current flows in the strata where they were most abundant. The manner in which plankters were affected (increasing or decreasing abundance) appeared to be modulated by their vertical position within the water column. The significant differences found at the high frequencies of this study, maintained across sampling days, suggest that nearshore meroplankton populations may have greater and more consistent temporal and vertical variability than previously considered.

  7. Armed conflict, homonegativity, and forced internal displacement: Implications for HIV among Colombian gay, bisexual, and transgender individuals

    PubMed Central

    Reisen, Carol A.; Bianchi, Fernanda T.; Gonzales, Felisa A.; Betancourt, Fabián; Aguilar, Marcela; Poppen, Paul J.

    2013-01-01

    Colombia has endured six decades of civil unrest, population displacement, and violence. We examined the relationships of contextual conditions, displacement, and HIV among gay, bisexual, and transgender individuals in Bogotá, Colombia. Nineteen key informants provided information about internal displacement of sexual minorities. Life history interviews were conducted with 42 participants aged 18 to 48 years, and included questions about displacement experiences, sexual behaviour, life prior to displacement, and participants’ economic and social situation in Bogotá. The interplay of a variety of factors—including internal conflict and violence, homonegativity and “social cleansing,” gender and sexual identity, and poverty—strongly shaped the varied experiences of displacement. Migration, sexual violence, exchange sex, and low rates of HIV testing were risk factors that increased vulnerability for HIV in this displaced sample. Although displacement and HIV in Colombia are major problems, both are understudied. PMID:23586420

  8. Armed conflict, homonegativity and forced internal displacement: implications for HIV among Colombian gay, bisexual and transgender individuals.

    PubMed

    Zea, Maria Cecilia; Reisen, Carol A; Bianchi, Fernanda T; Gonzales, Felisa A; Betancourt, Fabián; Aguilar, Marcela; Poppen, Paul J

    2013-01-01

    Colombia has endured six decades of civil unrest, population displacement and violence. We examined the relationships between contextual conditions, displacement and HIV among gay, bisexual and transgender individuals in Bogotá, Colombia. A total of 19 key informants provided information about internal displacement of sexual minorities. Life-history interviews were conducted with 42 participants aged 18 to 48 years and included questions about displacement experiences, sexual behaviour, life prior to displacement and participants' economic and social situation in Bogotá. The interplay of a variety of factors - including internal conflict and violence, homonegativity and 'social cleansing', gender and sexual identity and poverty - strongly shaped the varied experiences of displacement. Migration, sexual violence, exchange sex and low rates of HIV testing were risk factors that increased vulnerability for HIV in this displaced sample. Although displacement and HIV in Colombia are major problems, both are understudied. PMID:23586420

  9. The relevance of "non-criteria" clinical manifestations of antiphospholipid syndrome: 14th International Congress on Antiphospholipid Antibodies Technical Task Force Report on Antiphospholipid Syndrome Clinical Features.

    PubMed

    Abreu, Mirhelen M; Danowski, Adriana; Wahl, Denis G; Amigo, Mary-Carmen; Tektonidou, Maria; Pacheco, Marcelo S; Fleming, Norma; Domingues, Vinicius; Sciascia, Savino; Lyra, Julia O; Petri, Michelle; Khamashta, Munther; Levy, Roger A

    2015-05-01

    The purpose of this task force was to critically analyze nine non-criteria manifestations of APS to support their inclusion as APS classification criteria. The Task Force Members selected the non-criteria clinical manifestations according to their clinical relevance, that is, the patient-important outcome from clinician perspective. They included superficial vein thrombosis, thrombocytopenia, renal microangiopathy, heart valve disease, livedo reticularis, migraine, chorea, seizures and myelitis, which were reviewed by this International Task Force collaboration, in addition to the seronegative APS (SN-APS). GRADE system was used to evaluate the quality of evidence of medical literature of each selected item. This critical appraisal exercise aimed to support the debate regarding the clinical picture of APS. We found that the overall GRADE analysis was very low for migraine and seizures, low for superficial venous thrombosis, thrombocytopenia, chorea, longitudinal myelitis and the so-called seronegative APS and moderate for APS nephropathy, heart valve lesions and livedo reticularis. The next step can be a critical redefinition of an APS gold standard, for instance derived from the APS ACTION registry that will include not only current APS patients but also those with antiphospholipid antibodies not meeting current classification criteria. PMID:25641203

  10. The albedo field and cloud radiative forcing produced by a general circulation model with internally generated cloud optics

    NASA Technical Reports Server (NTRS)

    Charlock, T. P.; Ramanathan, V.

    1985-01-01

    A general circulation model (GCM) study is presented in which cloud radiative properties are computed from cloud liquid water content inferred from the GCM hydrological cycle. Model-generated and satellite albedos are in rough agreement. Analysis of the cloud radiative forcing indicates that cloud albedo effects overcome cloud infrared opacity effects in most regions. Both computed and observed albedo of clouds decrease from low to high altitudes. The model with variable cloud optics produces significantly different regional albedos from the same one with fixed cloud optics, especially over the tropics. The cloud droplet size distribution also has a significant impact on the model albedos. The temperature of the tropical upper troposphere is somewhat sensitive to the microphysical characteristics of the model cirrus clouds.

  11. Evaluation of the meteorological forcing used for the Air Quality Model Evaluation International Initiative (AQMEII) air quality simulations

    NASA Astrophysics Data System (ADS)

    Vautard, Robert; Moran, Michael D.; Solazzo, Efisio; Gilliam, Robert C.; Matthias, Volker; Bianconi, Roberto; Chemel, Charles; Ferreira, Joana; Geyer, Beate; Hansen, Ayoe B.; Jericevic, Amela; Prank, Marje; Segers, Arjo; Silver, Jeremy D.; Werhahn, Johannes; Wolke, Ralf; Rao, S. T.; Galmarini, Stefano

    2012-06-01

    Accurate regional air pollution simulation relies strongly on the accuracy of the mesoscale meteorological simulation used to drive the air quality model. The framework of the Air Quality Model Evaluation International Initiative (AQMEII), which involved a large international community of modeling groups in Europe and North America, offered a unique opportunity to evaluate the skill of mesoscale meteorological models for two continents for the same period. More than 20 groups worldwide participated in AQMEII, using several meteorological and chemical transport models with different configurations. The evaluation has been performed over a full year (2006) for both continents. The focus for this particular evaluation was meteorological parameters relevant to air quality processes such as transport and mixing, chemistry, and surface fluxes. The unprecedented scale of the exercise (one year, two continents) allowed us to examine the general characteristics of meteorological models' skill and uncertainty. In particular, we found that there was a large variability between models or even model versions in predicting key parameters such as surface shortwave radiation. We also found several systematic model biases such as wind speed overestimations, particularly during stable conditions. We conclude that major challenges still remain in the simulation of meteorology, such as nighttime meteorology and cloud/radiation processes, for air quality simulation.

  12. Organization of the United States International Communications Industry. Appendix. Report of the Panel on Satellites and Other Long-Haul Transmission Modes of the National Academy of Engineering. President's Task Force on Communications Policy. Staff Paper Two.

    ERIC Educational Resources Information Center

    Rostow, Eugene V.

    A staff paper to the President's Task Force on Communications Policy reviews the organization of the American international communications industries and recommends a consolidation of the competing international carriers. Particularly emphasized is the competition and division of ownership between the two technologies involved in international…

  13. Turbofan forced mixer-nozzle internal flowfield. Volume 3: A computer code for 3-D mixing in axisymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Kreskovsky, J. P.; Briley, W. R.; Mcdonald, H.

    1982-01-01

    A finite difference method is developed for making detailed predictions of three dimensional subsonic turbulent flow in turbofan lobe mixers. The governing equations are solved by a forward-marching solution procedure which corrects an inviscid potential flow solution for viscous and thermal effects, secondary flows, total pressure distortion and losses, internal flow blockage and pressure drop. Test calculations for a turbulent coaxial jet flow verify that the turbulence model performs satisfactorily for this relatively simple flow. Lobe mixer flows are presented for two geometries typical of current mixer design. These calculations included both hot and cold flow conditions, and both matched and mismatched Mach number and total pressure in the fan and turbine streams.

  14. Hydrological response in the Danube lower basin to some internal and external forcing factors of the climate system

    NASA Astrophysics Data System (ADS)

    Mares, Ileana; Dobrica, Venera; Demetrescu, Crisan; Mares, Constantin

    2016-04-01

    The precipitation in the Danube upper and middle basin is the main indicator for the Danube discharge at the entry in the lower basin. Along with precipitation, from the category of internal factors, in the first stage, we tried to find other predictors from the fields of temperature, pressure and geopotential. In the second phase, we considered external factors, taking into account the indices of solar/geomagnetic activity, represented by Wolf numbers, 10.7cm solar flux/aa geomagnetic index. In the Danube upper and middle basin, were considered fields of precipitation (PP), and temperatures (T) at 15 meteorological stations. The large-scale atmospheric circulation was quantified by Greenland-Balkan-Oscillation index (GBOI), North Atlantic Oscillation index and by blocking indices. The hydrological state in the Danube lower basin was represented by the discharge at the Orsova station. To estimate the discharge response in the Danube lower basin to various factors, developments in EOFs, cross correlations, power spectra, filters, composite maps were achieved. For the atmospheric variables, taken simultaneously, the most significant results (confidence level of 95%) are related to the predictors, considering the difference between standardized temperatures and precipitation (TPP), except for winter season, when the best predictors are PC1 of precipitation field and GBOI. In order to see the predictive hydrological response to the considered predictors, the correlative analyses with some lags were achieved. The significant results, were obtained for the winter/spring variables (PC1-precipitation and TPP), which can be considered good predictors for spring/summer discharge in the Danube lower basin. The hydrological response to the solar/ geomagnetic activity is given with a delay of two and three years. Due to the important signal of GBOI in the Danube basin precipitation in winter (correlation coefficient of 0.83), a stochastic modeling was performed between GBOI and

  15. Priming Silicic Giant Magma Bodies: Finding Evidence for Internal Forcing Versus External Triggering of Supereruptions by Phase Equilibria Modeling.

    NASA Astrophysics Data System (ADS)

    Tramontano, S.; Gualda, G. A. R.; Ghiorso, M. S.; Kennedy, B.

    2015-12-01

    It is important to understand what triggers silicic eruptions because of the implications for modern-day systems. The goal of this project is to use phase equilibria modeling (i.e. rhyolite-MELTS) to determine to what extent magmas within the crust are induced to erupt due to external triggers (e.g. earthquakes; new magma injection; neighboring eruptions) and to what extent they naturally evolve to a point where eruption is inevitable (e.g. by fluid exsolution and decrease in magma strength and density). Whole-rock compositions from four rhyolite tuffs across the globe associated with large or supereruptions (Mamaku Tuff, New Zealand; Peach Spring Tuff, SW USA; early and late-erupted Bishop Tuff, California; and Toba Tuff, Indonesia) are studied using rhyolite-MELTS modeling. Key physical properties of magma are strongly affected by the initial volatile content due to fluid exsolution. By running simulations with varying water contents, we can track the evolution of fluid exsolution during crystallization. Isobaric (constrained temperature change at constant pressure) and isochoric (constrained temperature change at constant volume) models were run for the four compositions. In constrained-pressure scenarios, fluid is free to exsolve as crystallization proceeds, and the total system volume can increase or decrease accordingly; this would require deformation of the surrounding crust to accommodate the magma volume change. In constrained-volume scenarios, bubble exsolution is limited to the volume change due to crystallization; in this case, pressure can decrease or increase (if bubbles are absent or present). For fixed-pressure scenarios, fluid exsolution is more extensive and leads to internal triggering, at least for fluid-saturated conditions; external triggering is more likely in fluid-undersaturated conditions. For fixed-volume scenarios, none of the systems cross a fragmentation threshold for the crystal contents typically observed in natural pumice. If

  16. Ground Reaction Forces and Gait Parameters during Motorized and Non-Motorized Treadmill Walking and Runing on the International Space Station Treadmill

    NASA Technical Reports Server (NTRS)

    Hagan, Ronald Donald; Norcross, Jason; DeWitt, John; Lee, Stuart M.; McCleary, Frank; Edwards, W. Brent

    2006-01-01

    Both motorized (T-M) and non-motorized (T-NM) treadmill locomotion are used on the International Space Station (ISS) as countermeasures to the deleterious effects of prolonged weightlessness. However, the ground reaction forces (GRF) and gait parameters of these exercise modes have not been examined. The purpose of this study was to determine if differences in GRF and gait parameters exist while walking (1.34 m/s) and running (3.13 m/s) on T-M and T-NM. Dissimilar GRF and gait parameters suggest that T-M and T-NM locomotion may elicit different physiologic effects. T-NM may result in a reduced stimulus to bone formation due to a lower LR, but an increased energy cost as a result of shorter, more frequent strides. Therefore, the usage of each mode should depend upon the desired training stimulus.

  17. What are the minimum requirements for ketogenic diet services in resource-limited regions? Recommendations from the International League Against Epilepsy Task Force for Dietary Therapy.

    PubMed

    Kossoff, Eric H; Al-Macki, Nabil; Cervenka, Mackenzie C; Kim, Heung D; Liao, Jianxiang; Megaw, Katherine; Nathan, Janak K; Raimann, Ximena; Rivera, Rocio; Wiemer-Kruel, Adelheid; Williams, Emma; Zupec-Kania, Beth A

    2015-09-01

    Despite the increasing use of dietary therapies for children and adults with refractory epilepsy, the availability of these treatments in developing countries with limited resources remains suboptimal. One possible contributory factor may be the costs. There is often reported a significant perceived need for a large ketogenic diet team, supplements, laboratory studies, and follow-up visits to provide this treatment. The 2009 Epilepsia Consensus Statement described ideal requirements for a ketogenic diet center, but in some situations this is not feasible. As a result, the International League Against Epilepsy (ILAE) Task Force on Dietary Therapy was asked to convene and provide practical, cost-effective recommendations for new ketogenic diet centers in resource-limited regions of the world. PMID:26033161

  18. Nutritional status of children and adolescents based on body mass index: agreement between World Health Organization and International Obesity Task Force

    PubMed Central

    Cavazzotto, Timothy Gustavo; Brasil, Marcos Roberto; Oliveira, Vinicius Machado; da Silva, Schelyne Ribas; Ronque, Enio Ricardo V.; Queiroga, Marcos Roberto; Serassuelo, Helio

    2014-01-01

    Objective: To investigate the agreement between two international criteria for classification of children and adolescents nutritional status. Methods: The study included 778 girls and 863 boys aged from six to 13 years old. Body mass and height were measured and used to calculate the body mass index. Nutritional status was classified according to the cut-off points defined by the World Health Organization and the International Obesity Task Force. The agreement was evaluated using Kappa statistic and weighted Kappa. Results: In order to classify the nutritional status, the agreement between the criteria was higher for the boys (Kappa 0.77) compared to girls (Kappa 0.61). The weighted Kappa was also higher for boys (0.85) in comparison to girls (0.77). Kappa index varied according to age. When the nutritional status was classified in only two categories - appropriate (thinness + accentuated thinness + eutrophy) and overweight (overweight + obesity + severe obesity) -, the Kappa index presented higher values than those related to the classification in six categories. Conclusions: A substantial agreement was observed between the criteria, being higher in males and varying according to the age. PMID:24676189

  19. International recommendation for a comprehensive neuropathologic workup of epilepsy surgery brain tissue: A consensus Task Force report from the ILAE Commission on Diagnostic Methods.

    PubMed

    Blümcke, Ingmar; Aronica, Eleonora; Miyata, Hajime; Sarnat, Harvey B; Thom, Maria; Roessler, Karl; Rydenhag, Bertil; Jehi, Lara; Krsek, Pavel; Wiebe, Samuel; Spreafico, Roberto

    2016-03-01

    Epilepsy surgery is an effective treatment in many patients with drug-resistant focal epilepsies. An early decision for surgical therapy is facilitated by a magnetic resonance imaging (MRI)-visible brain lesion congruent with the electrophysiologically abnormal brain region. Recent advances in the pathologic diagnosis and classification of epileptogenic brain lesions are helpful for clinical correlation, outcome stratification, and patient management. However, application of international consensus classification systems to common epileptic pathologies (e.g., focal cortical dysplasia [FCD] and hippocampal sclerosis [HS]) necessitates standardized protocols for neuropathologic workup of epilepsy surgery specimens. To this end, the Task Force of Neuropathology from the International League Against Epilepsy (ILAE) Commission on Diagnostic Methods developed a consensus standard operational procedure for tissue inspection, distribution, and processing. The aims are to provide a systematic framework for histopathologic workup, meeting minimal standards and maximizing current and future opportunities for morphofunctional correlations and molecular studies for both clinical care and research. Whenever feasible, anatomically intact surgical specimens are desirable to enable systematic analysis in selective hippocampectomies, temporal lobe resections, and lesional or nonlesional neocortical samples. Correct orientation of sample and the sample's relation to neurophysiologically aberrant sites requires good communication between pathology and neurosurgical teams. Systematic tissue sampling of 5-mm slabs along a defined anatomic axis and application of a limited immunohistochemical panel will ensure a reliable differential diagnosis of main pathologies encountered in epilepsy surgery. PMID:26839983

  20. International consensus classification of hippocampal sclerosis in temporal lobe epilepsy: a Task Force report from the ILAE Commission on Diagnostic Methods.

    PubMed

    Blümcke, Ingmar; Thom, Maria; Aronica, Eleonora; Armstrong, Dawna D; Bartolomei, Fabrice; Bernasconi, Andrea; Bernasconi, Neda; Bien, Christian G; Cendes, Fernando; Coras, Roland; Cross, J Helen; Jacques, Thomas S; Kahane, Philippe; Mathern, Gary W; Miyata, Haijme; Moshé, Solomon L; Oz, Buge; Özkara, Çiğdem; Perucca, Emilio; Sisodiya, Sanjay; Wiebe, Samuel; Spreafico, Roberto

    2013-07-01

    Hippocampal sclerosis (HS) is the most frequent histopathology encountered in patients with drug-resistant temporal lobe epilepsy (TLE). Over the past decades, various attempts have been made to classify specific patterns of hippocampal neuronal cell loss and correlate subtypes with postsurgical outcome. However, no international consensus about definitions and terminology has been achieved. A task force reviewed previous classification schemes and proposes a system based on semiquantitative hippocampal cell loss patterns that can be applied in any histopathology laboratory. Interobserver and intraobserver agreement studies reached consensus to classify three types in anatomically well-preserved hippocampal specimens: HS International League Against Epilepsy (ILAE) type 1 refers always to severe neuronal cell loss and gliosis predominantly in CA1 and CA4 regions, compared to CA1 predominant neuronal cell loss and gliosis (HS ILAE type 2), or CA4 predominant neuronal cell loss and gliosis (HS ILAE type 3). Surgical hippocampus specimens obtained from patients with TLE may also show normal content of neurons with reactive gliosis only (no-HS). HS ILAE type 1 is more often associated with a history of initial precipitating injuries before age 5 years, with early seizure onset, and favorable postsurgical seizure control. CA1 predominant HS ILAE type 2 and CA4 predominant HS ILAE type 3 have been studied less systematically so far, but some reports point to less favorable outcome, and to differences regarding epilepsy history, including age of seizure onset. The proposed international consensus classification will aid in the characterization of specific clinicopathologic syndromes, and explore variability in imaging and electrophysiology findings, and in postsurgical seizure control. PMID:23692496

  1. Data mining of external and internal forcing of fluvial systems for catchment management: A case study on the Red River (Song Hong), Vietnam

    NASA Astrophysics Data System (ADS)

    Schmitt, Rafael; Bizzi, Simone; Castelletti, Andrea

    2013-04-01

    The understanding of river hydromorphological processes has been recognized in the last decades as a priority of modern catchment management, since interactions of natural and anthropogenic forces within the catchment drives fluvial geomorphic processes, which shape physical habitat, affect river infrastructures and influence freshwater ecological processes. The characterization of river hydromorphological features is commonly location and time specific and highly resource demanding. Therefore, its routine application at regional or national scales and the assessment of spatio-temporal changes as reaction to internal and external disturbances is rarely feasible at present. Information ranging from recently available high-resolution remote-sensing data (such as DEM), historic data such as land use maps or aerial photographs and monitoring networks of flow and rainfall, open up novel and promising capacity for basin-wide understanding of dominant hydromorphological drivers. Analysing the resulting multiparametric data sets in their temporal and spatial dimensions requires sophisticated data mining tools to exploit the potential of this information. We propose a novel framework that allows for the quantitative assessment of multiparametric data sets to identify classes of channel reaches characterized by similar geomorphic drivers using remote-sensing data and monitoring networks available in the catchment. This generic framework was applied to the Red River (Song Hong) basin, the second largest basin (87,800 sq.km) in Vietnam. Besides its economic importance, the river is experiencing severe river bed incisions due to recent construction of new dams in the upstream part of the catchment and sand mining in the surrounding of the capital city Hanoi. In this context, characterized by an high development rate, current efforts to increase water productivity and minimize impacts on the fluvial systems by means of focused infrastructure and management measures require a

  2. The swim force as a body force

    NASA Astrophysics Data System (ADS)

    Yan, Wen; Brady, John

    2015-11-01

    Net (as opposed to random) motion of active matter results from an average swim (or propulsive) force. It is shown that the average swim force acts like a body force - an internal body force [Yan and Brady, Soft Matter, DOI:10.1039/C5SM01318F]. As a result, the particle-pressure exerted on a container wall is the sum of the swim pressure [Takatori et al., Phys. Rev. Lett., 2014, 113, 028103] and the `weight' of the active particles. A continuum mechanical description is possible when variations occur on scales larger than the run length of the active particles and gives a Boltzmann-like distribution from a balance of the swim force and the swim pressure. Active particles may also display `action at a distance' and accumulate adjacent to (or be depleted from) a boundary without any external forces. In the momentum balance for the suspension - the mixture of active particles plus fluid - only external body forces appear.

  3. A magnesium-induced RNA conformational switch at the internal ribosome entry site of hepatitis C virus genome visualized by atomic force microscopy.

    PubMed

    García-Sacristán, Ana; Moreno, Miguel; Ariza-Mateos, Ascensión; López-Camacho, Elena; Jáudenes, Rosa M; Vázquez, Luis; Gómez, Jordi; Martín-Gago, José Ángel; Briones, Carlos

    2015-01-01

    The 5' untranslated region of hepatitis C virus (HCV) genomic RNA contains an internal ribosome entry site (IRES) element, composed of domains II-IV, which is required for cap-independent translation initiation. Little information on the 3D structure of the whole functional HCV IRES is still available. Here, we use atomic force microscopy to visualize the HCV IRES conformation in its natural sequence context, which includes the upstream domain I and the essential, downstream domains V and VI. The 574 nt-long molecule analyzed underwent an unexpected, Mg(2+)-induced switch between two alternative conformations: from 'open', elongated morphologies at 0-2 mM Mg(2+) concentration to a 'closed', comma-shaped conformation at 4-6 mM Mg(2+). This sharp transition, confirmed by gel-shift analysis and partial RNase T1 cleavage, was hindered by the microRNA miR-122. The comma-shaped IRES-574 molecules visualized at 4-6 mM Mg(2+) in the absence of miR-122 showed two arms. Our data support that the first arm would contain domain III, while the second one would be composed of domains (I-II)+(V-VI) thanks to a long-range RNA interaction between the I-II spacer and the basal region of domain VI. This reinforces the previously described structural continuity between the HCV IRES and its flanking domains I, V and VI. PMID:25510496

  4. Review of current best practice and priorities for research in radiation oncology for elderly patients with cancer: the International Society of Geriatric Oncology (SIOG) task force.

    PubMed

    Kunkler, I H; Audisio, R; Belkacemi, Y; Betz, M; Gore, E; Hoffe, S; Kirova, Y; Koper, P; Lagrange, J-L; Markouizou, A; Pfeffer, R; Villa, S

    2014-11-01

    Radiotherapy (RT) is a key component of the management of older cancer patients. Level I evidence in older patients is limited. The International Society of Geriatric Oncology (SIOG) established a task force to make recommendations for curative RT in older patients and to identify future research priorities. Evidence-based guidelines are provided for breast, lung, endometrial, prostate, rectal, pancreatic, oesophageal, head and neck, central nervous system malignancies and lymphomas. Patient selection should include comorbidity and geriatric evaluation. Advances in radiation planning and delivery improve target coverage, reduce toxicity and widen eligibility for treatment. Shorter courses of hypofractionated whole breast RT are safe and effective. Conformal RT and involved-field techniques without elective nodal irradiation have improved outcomes in non-small-cell lung cancer (NSCLC) without increasing toxicity. Where comorbidities preclude surgery, stereotactic body radiotherapy (SBRT) is an option for early-stage NSCLC and pancreatic cancer. Modern involved-field RT for lymphoma based on pre-treatment positron emission tomography data has reduced toxicity. Significant comorbidity is a relative contraindication to aggressive treatment in low-risk prostate cancer (PC). For intermediate-risk disease, 4-6 months of hormones are combined with external beam radiotherapy (EBRT). For high-risk PC, combined modality therapy (CMT) is advised. For high-intermediate risk, endometrial cancer vaginal brachytherapy is recommended. Short-course EBRT is an alternative to CMT in older patients with rectal cancer without significant comorbidities. Endorectal RT may be an option for early disease. For primary brain tumours, shorter courses of postoperative RT following maximal debulking provide equivalent survival to longer schedules. MGMT methylation status may help select older patients for temozolomide alone. Stereotactic RT provides an alternative to whole-brain RT in patients

  5. Forceful emplacement of the Eureka Valley-Joshua Flat-Beer Creek composite pluton into a structural basin in eastern California; internal structure and wall rock deformation

    NASA Astrophysics Data System (ADS)

    Morgan, Sven; Law, Richard; de Saint Blanquat, Michel

    2013-11-01

    Anisotropy of Magnetic Susceptibility parameters have been analyzed at 311 locations in the Eureka Valley-Joshua Flat-Beer Creek (EJB) pluton of eastern California. The large amount of data has allowed for the AMS parameters to be contoured using techniques that both reveal map-scale trends and emphasize small-scale differences. The contour maps suggest that magnetic susceptibility is dominantly controlled by composition of the magma but may also be affected by emplacement-related strain as the magma chamber inflated and forced the wall rocks outward. Pluton construction involved two major pulses of different composition magmas that were emplaced sequentially but with overlapping periods of crystallization. The magmas initially intruded as sill-like bodies into a structural basin. The magnetic foliation of the pluton cuts across internal magmatic contacts on the map scale and is parallel to local contacts between the pluton and surrounding metasedimentary wall rocks. The magnetic fabric is similar in orientation and symmetry to intense flattening strains recorded in the aureole rocks. The metasedimentary wall rocks have been shortened between 60 and 70% and this strain magnitude is approximately equal on the west, south, and east margins of the pluton. Strain in the wall rocks is dominantly flattening and concentrated into a narrow (1 km wide) inner aureole. Mapping of bedding/cleavage intersection lineations south of the pluton indicates that the magma made room for itself by translating the wall rocks outward and rotating the already inward dipping wall rocks of the structural basin to sub-vertical. Stretching of the inner aureole around an expanding magma chamber was responsible for the intense shortening. Limited data on the Marble Canyon pluton to the south of the EJB pluton indicates a very similar emplacement process.

  6. The molecular structure, conformation, potential to internal rotation and force field of 2,2,2-trifluoroacetamide as studied by gas electron diffraction and quantum chemical calculations

    NASA Astrophysics Data System (ADS)

    Gundersen, Snefrid; Samdal, Svein; Seip, Ragnhild; Shorokhov, Dmitry J.; Strand, Tor G.

    1998-04-01

    2,2,2-Trifluoroacetamide (TFA) has been studied by electron diffraction (ED), ab initio Hartree-Fock (HF), density functional theory (DFT), and MP2 calculations. The calculations give one conformation with one of the CF bonds anti to the CO bond and a planar NH 2 group, except for MP2/6-311 + + G∗∗, which predicts a slightly pyramidale NH 2 group. A molecular force field has been determined, and the fundamental frequencies have tentatively been assigned. The refined structural parameters were determined using constrained ED, i.e. ab initio results are included as constraints in the analysis. The structural parameters are: rg(N-H 4) = 1.040(4), rg(CO) = 1.211(2), rg(C-N) = 1.362(4), rg = 1.562(1), rg(C-F 7) = 1.347(1), ∠ αOCN = 126.5(2), ∠ αCCN = 116.3(4), ∠ αCCF 7 = 111.9(1), and ∠ αCNH 4 = 118.5(11). Bond distances are in Å and bond angles in degrees. Uncertainties are one standard deviation from least squares refinement using a diagonal weight matrix and inclusion of the uncertainty in the electron wavelength. The structural parameters have been compared with related amides. The Fourier coefficients V3 and V6 in the potential to internal rotation of the CF 3 group, V(α) = 1/2∗V 3∗(1 - cos(3∗α)) + 1/2∗V 6∗(1 - cos(6∗α)) , are determined to be 2.7(4) and - 0.7(3) kJ/mol, respectively. The syn barrier is experimentally determined to be 2.6(4) kJ/mol, which is in good agreeent with theoretical calculations.

  7. A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object

    SciTech Connect

    Unseren, M.A.

    1997-09-01

    The report reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restricts the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  8. Electrodynamic force law controversy.

    PubMed

    Graneau, P; Graneau, N

    2001-05-01

    Cavalleri et al. [Phys. Rev. E 52, 2505 (1998); Eur. J. Phys. 17, 205 (1996)] have attempted to resolve the electrodynamic force law controversy. This attempt to prove the validity of either the Ampère or Lorentz force law by theory and experiment has revealed only that the two are equivalent when predicting the force on part of a circuit due to the current in the complete circuit. However, in our analysis of internal stresses, only Ampère's force law agrees with experiment. PMID:11415053

  9. External and Internal Influences as Driving Forces and/or Stumbling-Blocks in the Development of the South African Quality Assurance System Nationally as Well as Institutionally.

    ERIC Educational Resources Information Center

    van der Westhuizen, L. J.

    2002-01-01

    Examines the most important internal and external environmental influences directing or hampering national and institutional quality assurance and management developments, as well as their implementation, in the South African higher education system. (EV)

  10. Force propagation and force generation in cells.

    PubMed

    Jonas, Oliver; Duschl, Claus

    2010-09-01

    Determining how forces are produced by and propagated through the cytoskeleton (CSK) of the cell is of great interest as dynamic processes of the CSK are intimately correlated with many molecular signaling pathways. We are presenting a novel approach for integrating measurements on cell elasticity, transcellular force propagation, and cellular force generation to obtain a comprehensive description of dynamic and mechanical properties of the CSK under force loading. This approach uses a combination of scanning force microscopy (SFM) and Total Internal Reflection Fluorescence (TIRF) microscopy. We apply well-defined loading schemes onto the apical cell membrane of fibroblasts using the SFM and simultaneously use TIRF microscopy to image the topography of the basal cell membrane. The locally distinct changes of shape and depth of the cytoskeletal imprints onto the basal membrane are interpreted as results of force propagation through the cytoplasm. This observation provides evidence for the tensegrity model and demonstrates the usefulness of our approach that does not depend on potentially disturbing marker compounds. We confirm that the actin network greatly determines cell stiffness and represents the substrate that mediates force transduction through the cytoplasm of the cell. The latter is an essential feature of tensegrity. Most importantly, our new finding that, both intact actin and microtubule networks are required for enabling the cell to produce work, can only be understood within the framework of the tensegrity model. We also provide, for the first time, a direct measurement of the cell's mechanical power output under compression at two femtowatts. PMID:20607861

  11. DESIGNING DRUG TRIALS FOR SARCOPENIA IN OLDER ADULTS WITH HIP FRACTURE - A TASK FORCE FROM THE INTERNATIONAL CONFERENCE ONFRAILTY AND SARCOPENIA RESEARCH (ICFSR).

    PubMed

    Vellas, B; Fielding, R; Miller, R; Rolland, Y; Bhasin, S; Magaziner, J; Bischoff-Ferrari, H

    2014-01-01

    In May 2012, a Sarcopenia Consensus Summit was convened by the Foundation of the National Institutes of Health (FNIH), National Institute of Aging (NIA), and the U.S. Food and Drug Administration (FDA); and co-sponsored by five pharmaceutical companies. At this summit, sarcopenia experts from around the world worked to develop agreement on a working definition of sarcopenia, building on the work of previous efforts to generate a consensus. With the ultimate goal of improving function and independence in individuals with sarcopenia, the Task Force focused its attention on people at greatly increased risk of muscle atrophy as a consequence of hip fracture. The rationale for looking at this population is that since hip fracture is a recognized condition, there is a clear regulatory path forward for developing interventions. Moreover, patients with hip fracture may provide an appropriate population to advance understanding of sarcopenia, for example helping to define diagnostic criteria, develop biomarkers, understand the mechanisms that underlie the age-related loss of muscle mass and strength, and identify endpoints for clinical trials that are reliable, objective, and clinically meaningful. Task Force members agreed that progress in treating sarcopenia will require strengthening of partnerships between academia, industry, and government agencies, and across continents to reach consensus on diagnostic criteria, optimization of clinical trials design, and identification of improved treatment and preventive strategies. In this report, the main results of the Task Force discussion are presented. PMID:26380231

  12. Nuclear forces

    SciTech Connect

    Machleidt, R.

    2013-06-10

    These lectures present an introduction into the theory of nuclear forces. We focus mainly on the modern approach, in which the forces between nucleons emerge from low-energy QCD via chiral effective field theory.

  13. Labor Force

    ERIC Educational Resources Information Center

    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…

  14. The rotation-vibration structure of the SO2 C1B2 state explained by a new internal coordinate force field

    DOE PAGESBeta

    Jiang, Jun; Park, G. Barratt; Field, Robert W.

    2016-04-14

    A new quartic force field for the SO2 C~1B2 state has been derived, based on high resolution data from S16O2 and S18O2. Included are eight b2 symmetry vibrational levels of S16O2 reported in the first paper of this series [G. B. Park, et al., J. Chem. Phys. 144, 144311 (2016)]. Many of the experimental observables not included in the fit, such as the Franck-Condon intensities and the Coriolis-perturbed effective C rotational constants of highly anharmonic C~ state vibrational levels, are well reproduced using our force field. Because the two stretching modes of the C~ state are strongly coupled via Fermi-133more » interaction, the vibrational structure of the C state is analyzed in a Fermi-system basis set, constructed explicitly in this work via partial diagonalization of the vibrational Hamiltonian. The physical significance of the Fermi-system basis is discussed in terms of semiclassical dynamics, based on study of Fermi-resonance systems by Kellman and coworkers [M. E. Kellman and L. Xiao, J. Chem. Phys. 93, 5821 (1990)]. By diagonalizing the vibrational Hamiltonian in the Fermi-system basis, the vibrational characters of all vibrational levels can be determined unambiguously. It is shown that the bending mode cannot be treated separately from the coupled stretching modes, particularly at vibrational energies of more than 2000 cm–1. Based on our force field, the structure of the Coriolis interactions in the C~ state of SO2 is also discussed. As a result, we identify the origin of the alternating patterns in the effective C rotational constants of levels in the vibrational progressions of the symmetry-breaking mode, νβ (which correlates with the antisymmetric stretching mode in our assignment scheme).« less

  15. The Persistence Length of DNA Is Reached from the Persistence Length of Its Null Isomer through an Internal Electrostatic Stretching Force

    PubMed Central

    Manning, Gerald S.

    2006-01-01

    To understand better the effect of electrostatics on the rigidity of the DNA double helix, we define DNA*, the null isomer of DNA, as the hypothetical structure that would result from DNA if its phosphate groups were not ionized. For the purposes of theoretical analysis, we model DNA* as identical to ordinary DNA but supplemented by a longitudinal compression force equal in magnitude but oppositely directed to the stretching (tension) force on DNA caused by phosphate-phosphate repulsions. The null isomer DNA* then becomes an elastically buckled form of fully ionized DNA. On this basis, we derive a nonadditive relationship between the persistence length P of DNA and the persistence length P* of its null isomer. From the formula obtained we can predict the value of P* if P is known, and we can predict the ionic strength dependence of P under the assumption that P* does not depend on ionic strength. We predict a value of P* for null DNA drastically lower than the value of P for DNA in its ordinary state of fully ionized phosphates. The predicted dependence of P on salt concentration is log-c over most of the concentration range, with no tendency toward a salt-independent value in the range of validity of the theory. The predictions are consistent with much of the persistence-length data available for DNA. Alternate theories of the Odijk-Skolnik-Fixman type, including one by the author, are considered skeptically on the grounds that the underlying model may not be realistic. Specifically, we doubt the accuracy for real polyelectrolytes of the Odijk-Skolnik-Fixman assumption that the polymer structure is invariant to changes in electrostatic forces. PMID:16935960

  16. The rotation-vibration structure of the SO2 C̃(1)B2 state explained by a new internal coordinate force field.

    PubMed

    Jiang, Jun; Park, G Barratt; Field, Robert W

    2016-04-14

    A new quartic force field for the SO2 C̃(1)B2 state has been derived, based on high resolution data from S(16)O2 and S(18)O2. Included are eight b2 symmetry vibrational levels of S(16)O2 reported in the first paper of this series [G. B. Park et al., J. Chem. Phys. 144, 144311 (2016)]. Many of the experimental observables not included in the fit, such as the Franck-Condon intensities and the Coriolis-perturbed effective C rotational constants of highly anharmonic C̃ state vibrational levels, are well reproduced using our force field. Because the two stretching modes of the C̃ state are strongly coupled via Fermi-133 interaction, the vibrational structure of the C̃ state is analyzed in a Fermi-system basis set, constructed explicitly in this work via partial diagonalization of the vibrational Hamiltonian. The physical significance of the Fermi-system basis is discussed in terms of semiclassical dynamics, based on study of Fermi-resonance systems by Kellman and Xiao [J. Chem. Phys. 93, 5821 (1990)]. By diagonalizing the vibrational Hamiltonian in the Fermi-system basis, the vibrational characters of all vibrational levels can be determined unambiguously. It is shown that the bending mode cannot be treated separately from the coupled stretching modes, particularly at vibrational energies of more than 2000 cm(-1). Based on our force field, the structure of the Coriolis interactions in the C̃ state of SO2 is also discussed. We identify the origin of the alternating patterns in the effective C rotational constants of levels in the vibrational progressions of the symmetry-breaking mode, νβ (which correlates with the antisymmetric stretching mode in our assignment scheme). PMID:27083726

  17. The rotation-vibration structure of the SO2 C ˜ 1B2 state explained by a new internal coordinate force field

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Park, G. Barratt; Field, Robert W.

    2016-04-01

    A new quartic force field for the SO2 C ˜ 1B2 state has been derived, based on high resolution data from S16O2 and S18O2. Included are eight b2 symmetry vibrational levels of S16O2 reported in the first paper of this series [G. B. Park et al., J. Chem. Phys. 144, 144311 (2016)]. Many of the experimental observables not included in the fit, such as the Franck-Condon intensities and the Coriolis-perturbed effective C rotational constants of highly anharmonic C ˜ state vibrational levels, are well reproduced using our force field. Because the two stretching modes of the C ˜ state are strongly coupled via Fermi-133 interaction, the vibrational structure of the C ˜ state is analyzed in a Fermi-system basis set, constructed explicitly in this work via partial diagonalization of the vibrational Hamiltonian. The physical significance of the Fermi-system basis is discussed in terms of semiclassical dynamics, based on study of Fermi-resonance systems by Kellman and Xiao [J. Chem. Phys. 93, 5821 (1990)]. By diagonalizing the vibrational Hamiltonian in the Fermi-system basis, the vibrational characters of all vibrational levels can be determined unambiguously. It is shown that the bending mode cannot be treated separately from the coupled stretching modes, particularly at vibrational energies of more than 2000 cm-1. Based on our force field, the structure of the Coriolis interactions in the C ˜ state of SO2 is also discussed. We identify the origin of the alternating patterns in the effective C rotational constants of levels in the vibrational progressions of the symmetry-breaking mode, νβ (which correlates with the antisymmetric stretching mode in our assignment scheme).

  18. 22 CFR 130.3 - Armed forces.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force, or coast guard,...

  19. 22 CFR 130.3 - Armed forces.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force, or coast guard,...

  20. 22 CFR 130.3 - Armed forces.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force, or coast guard,...

  1. 22 CFR 130.3 - Armed forces.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force, or coast guard,...

  2. 22 CFR 130.3 - Armed forces.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS POLITICAL CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force, or coast guard,...

  3. From local force-flux relationships to internal dissipations and their impact on heat engine performance: the illustrative case of a thermoelectric generator.

    PubMed

    Apertet, Y; Ouerdane, H; Goupil, C; Lecoeur, Ph

    2013-08-01

    We present an in-depth analysis of the sometimes understated role of the principle of energy conservation in linear irreversible thermodynamics. Our case study is that of a thermoelectric generator (TEG), which is a heat engine of choice in irreversible thermodynamics, owing to the coupling between the electrical and heat fluxes. We show why Onsager's reciprocal relations must be considered locally and how internal dissipative processes emerge from the extension of these relations to a global scale: The linear behavior of a heat engine at the local scale is associated with a dissipation process that must partake in the global energy balance. We discuss the consequences of internal dissipations on the so-called efficiency at maximum power, in the light of our comparative analyses of exoreversibility and endoreversibility on the one hand and of two classes of heat engines, autonomous and periodically driven, on the other hand. Finally, basing our analysis on energy conservation, we also discuss recent works which claim the possibility to overcome the traditional boundaries on efficiency imposed by finite-time thermodynamics in thermoelectric systems with broken time-reversal symmetry; this we do by introducing a "thermal" thermopower and an "electrical" thermopower which permits an analysis of the thermoelectric response of the TEG considering a possible dissymmetry between the electrical/thermal and the thermal/electrical couplings. PMID:24032805

  4. HRP ForceShoe Evaluation

    NASA Video Gallery

    Maintaining astronaut bone and muscle health in microgravity is an ongoing concern for NASA. In May of 2014, NASA delivered the ForceShoe, designed by XSENS, to the International Space Station (ISS...

  5. Criteria for intraventricular conduction disturbances and pre-excitation. World Health Organizational/International Society and Federation for Cardiology Task Force Ad Hoc.

    PubMed

    Willems, J L; Robles de Medina, E O; Bernard, R; Coumel, P; Fisch, C; Krikler, D; Mazur, N A; Meijler, F L; Mogensen, L; Moret, P

    1985-06-01

    In an effort to standardize terminology and criteria for clinical electrocardiography, and as a follow-up of its work on definitions of terms related to cardiac rhythm, an Ad Hoc Working Group established by the World Health Organization and the International Society and Federation of Cardiology reviewed criteria for the diagnosis of conduction disturbances and pre-excitation. Recommendations resulting from these discussions are summarized for the diagnosis of complete and incomplete right and left bundle branch block, left anterior and left posterior fascicular block, nonspecific intraventricular block, Wolff-Parkinson-White syndrome and related pre-excitation patterns. Criteria for intraatrial conduction disturbances are also briefly reviewed. The criteria are described in clinical terms. A concise description of the criteria using formal Boolean logic is given in the Appendix. For the incorporation into computer electrocardiographic analysis programs, the limits of some interval measurements may need to be adjusted. PMID:3889097

  6. Minimum requirements for the diagnosis of psychogenic nonepileptic seizures: a staged approach: a report from the International League Against Epilepsy Nonepileptic Seizures Task Force.

    PubMed

    LaFrance, W Curt; Baker, Gus A; Duncan, Rod; Goldstein, Laura H; Reuber, Markus

    2013-11-01

    An international consensus group of clinician-researchers in epilepsy, neurology, neuropsychology, and neuropsychiatry collaborated with the aim of developing clear guidance on standards for the diagnosis of psychogenic nonepileptic seizures (PNES). Because the gold standard of video electroencephalography (vEEG) is not available worldwide, or for every patient, the group delineated a staged approach to PNES diagnosis. Using a consensus review of the literature, this group evaluated key diagnostic approaches. These included: history, EEG, ambulatory EEG, vEEG/monitoring, neurophysiologic, neurohumoral, neuroimaging, neuropsychological testing, hypnosis, and conversation analysis. Levels of diagnostic certainty were developed including possible, probable, clinically established, and documented diagnosis, based on the availability of history, witnessed event, and investigations, including vEEG. The aim and hope of this report is to provide greater clarity about the process and certainty of the diagnosis of PNES, with the intent to improve the care for people with epilepsy and nonepileptic seizures. PMID:24111933

  7. Labor Force

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    The labor force is the number of people aged 16 or older who are either working or looking for work. It does not include active-duty military personnel or institutionalized people, such as prison inmates. Quantifying this total supply of labor is a way of determining how big the economy can get. Labor force participation rates vary significantly…

  8. One Force

    NASA Astrophysics Data System (ADS)

    Kotas, Ronald R.

    2002-04-01

    There is only one entity that can extend force and couple through space; and it should be apparent that Electromagnetism is that entity. In the cases of the nuclear strong force and the nuclear weak force, this is the same fundamental Electromagnetism manifesting itself in two different ways in the nucleus. It remains the same basic Electromagnetism. On the other hand, General Relativity fails to produce force at a distance, fails the Cavendish experiment, and does not allow an apple to fall to the ground. The result shows there is only Electromagnetism that functions through physical nature providing gravity, actions in the nucleus, as well as all other physical actions universally, including Gravity and Gravitation. There are many direct proofs of this, the same proofs as in NUCLEAR QUANTUM GRAVITATION. In contrast, General Relativity plainly relies on fallacy abstract and incoherent proofs; proofs which have now been mostly disproved. In the past it was deemed necessary by some to have an "ether" to propagate Electromagnetic waves. The fallacy concept of time space needs "space distortions" in order to cause gravity. However, Electromagnetic gravity does not have this problem. Clearly there is only ONE FORCE that causes Gravity, Electromagnetism, the Nuclear Strong Force, and the Nuclear Weak Force, and that ONE FORCE is Electromagnetism.

  9. The role of the International Society of Nephrology/Renal Disaster Relief Task Force in the rescue of renal disaster victims.

    PubMed

    Vanholder, R; Van Biesen, W; Lameire, N; Sever, M S

    2007-01-01

    Disasters are a major cause of distress and material as well as corporal damage. Next to direct trauma, the crush syndrome inducing multiorgan problems as a consequence of muscle compression and the release of muscular contents into the bloodstream is the most important cause of death; this is to a large extent related to the induction of severe acute kidney injury, for which dialysis is a life-saving therapy. The practical means (both hardware and personnel) to do so are, however, often lacking in disaster conditions. The Renal Disaster Relief Task Force (RDRTF) offered support for renal problems in the aftermath of several disasters, e.g. the Marmara earthquake (1999) in Turkey, the Bam earthquake (2003) in Iran, and the Kashmir earthquake (2005) in Pakistan. A preconceived intervention plan is followed with adaptations according to local conditions. Material and personnel are dispatched to the disaster areas. These interventions have been life-saving for a substantial number of victims. The current article describes the structure and approach of the RDRTF. PMID:17464143

  10. Flood sensitivity of the Bavarian Alpine Foreland since the late Middle Ages in the context of internal and external climate forcing factors

    NASA Astrophysics Data System (ADS)

    Böhm, O.; Jacobeit, J.; Glaser, R.; Wetzel, K.-F.

    2015-12-01

    This paper describes the flood sensitivity of the Bavarian part of the Alpine Foreland of Germany and addresses different questions concerning climate variability and flood frequencies, from the 14th century until today. The focal point of the paper is the flood frequency of the superordinate spatial unit of the Bavarian Foreland. Based on written historical sources, the flood history of the Alpine Foreland of Germany can be reconstructed back to the 14th century. One major result is the occurrence of "flood-rich" and "flood-poor" episodes in almost cyclical sequences. Flood-rich periods, before the 16th century based on limited available data, were recorded in the periods 1300-1335, 1370-1450, 1470-1525, 1555-1590, 1615-1665, 1730-1780, 1820-1870, and 1910-1955 as well as in a ninth period beginning in 1980. The flood-rich periods are characterized by longer flood duration. Most of the flood-rich and flood-poor periods (in particular the beginning and the end of them) can be connected to changes in natural climate variability. These include changing sunspot numbers (as a measure of solar activity), so-called Little Ice Age type events (LIATEs) as well as changes in the North Atlantic Oscillation (NAO). Climate signals from external forcing factors, which could be used to explain the changing flood frequencies in the Bavarian Alpine Foreland, end in 1930. Relationships within the climate system such as the correlation of flood frequencies with the NAO have changed during the transition from the post Little Ice Age period to the Modern Climate Optimum around 1930. Natural climate variability might have been overlaid by anthropogenic climate change.

  11. Force sensor

    DOEpatents

    Grahn, Allen R.

    1993-01-01

    A force sensor and related method for determining force components. The force sensor includes a deformable medium having a contact surface against which a force can be applied, a signal generator for generating signals that travel through the deformable medium to the contact surface, a signal receptor for receiving the signal reflected from the contact surface, a generation controller, a reception controller, and a force determination apparatus. The signal generator has one or more signal generation regions for generating the signals. The generation controller selects and activates the signal generation regions. The signal receptor has one or more signal reception regions for receiving signals and for generating detections signals in response thereto. The reception controller selects signal reception regions and detects the detection signals. The force determination apparatus measures signal transit time by timing activation and detection and, optionally, determines force components for selected cross-field intersections. The timer which times by activation and detection can be any means for measuring signal transit time. A cross-field intersection is defined by the overlap of a signal generation region and a signal reception region.

  12. Force sensor

    DOEpatents

    Grahn, A.R.

    1993-05-11

    A force sensor and related method for determining force components is described. The force sensor includes a deformable medium having a contact surface against which a force can be applied, a signal generator for generating signals that travel through the deformable medium to the contact surface, a signal receptor for receiving the signal reflected from the contact surface, a generation controller, a reception controller, and a force determination apparatus. The signal generator has one or more signal generation regions for generating the signals. The generation controller selects and activates the signal generation regions. The signal receptor has one or more signal reception regions for receiving signals and for generating detections signals in response thereto. The reception controller selects signal reception regions and detects the detection signals. The force determination apparatus measures signal transit time by timing activation and detection and, optionally, determines force components for selected cross-field intersections. The timer which times by activation and detection can be any means for measuring signal transit time. A cross-field intersection is defined by the overlap of a signal generation region and a signal reception region.

  13. Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China's Labor-Force Dynamic Survey.

    PubMed

    Gong, Xiao; Luo, Xiaofeng; Ling, Li

    2016-04-01

    Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women's reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women's risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%-46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%-36.97%)). Multivariate analysis showed that participants with a marital status of "Widowed" had statistically lower exposure rates, while those with a status of "Cohabitation" had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants' different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS. PMID:27043604

  14. 26 CFR 301.7701-8 - Military or naval forces and Armed Forces of the United States.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 18 2013-04-01 2013-04-01 false Military or naval forces and Armed Forces of... § 301.7701-8 Military or naval forces and Armed Forces of the United States. The term “military or naval forces of the United States” and the term “Armed Forces of the United States” each includes all...

  15. 26 CFR 301.7701-8 - Military or naval forces and Armed Forces of the United States.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 18 2011-04-01 2011-04-01 false Military or naval forces and Armed Forces of... § 301.7701-8 Military or naval forces and Armed Forces of the United States. The term “military or naval forces of the United States” and the term “Armed Forces of the United States” each includes all...

  16. 26 CFR 301.7701-8 - Military or naval forces and Armed Forces of the United States.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 18 2012-04-01 2012-04-01 false Military or naval forces and Armed Forces of... § 301.7701-8 Military or naval forces and Armed Forces of the United States. The term “military or naval forces of the United States” and the term “Armed Forces of the United States” each includes all...

  17. 26 CFR 301.7701-8 - Military or naval forces and Armed Forces of the United States.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Military or naval forces and Armed Forces of... § 301.7701-8 Military or naval forces and Armed Forces of the United States. The term “military or naval forces of the United States” and the term “Armed Forces of the United States” each includes all...

  18. 26 CFR 301.7701-8 - Military or naval forces and Armed Forces of the United States.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 18 2014-04-01 2014-04-01 false Military or naval forces and Armed Forces of... § 301.7701-8 Military or naval forces and Armed Forces of the United States. The term “military or naval forces of the United States” and the term “Armed Forces of the United States” each includes all...

  19. Flood history of the Bavarian Alpine Foreland since the late Middle Ages in the context of internal and external climate forcing factors

    NASA Astrophysics Data System (ADS)

    Böhm, O.; Jacobeit, J.; Glaser, R.; Wetzel, K.-F.

    2014-07-01

    This paper describes the flood history of the Bavarian part of the Alpine Foreland of Germany and addresses different questions concerning climate variability and flood frequencies from the 13th century until today. Will recent climatic change modify the flood frequencies within the Bavarian Alpine Foreland or are the flood frequencies varying due to altering climatic conditions since historical times? In the context of recent discussions whether man-made climate change will modify the present state of flood frequencies, a look back into the past is essential to understand the occurrence of floods in general and of recent floods in particular. In order to understand climatic variability and changes in a comprehensive way, it is necessary to review long time series. A perceived increase of summer floods in eastern Germany and Bavaria since 1997 requires examination of long time series to estimate changes in flood frequencies in a proper way. In view of the annual distribution of flood events within the Alpine Foreland of Germany, summer floods prove to be most important. Based on written historical sources, the flood history of the Alpine Foreland of Germany can be reconstructed back to the 14th century. One major result is the occurrence of "flood-rich" and "flood-poor" episodes in nearly cyclical sequences. Flood-rich periods were recorded in the periods 1300-1335, 1370-1450, 1470-1525, 1555-1590, 1615-1665, 1730-1780, 1820-1870, and 1910-1955 as well as in a 9th period beginning in 1980. The flood-rich periods are characterized by longer flood durations. Most of the flood-rich and flood-poor periods (in particular the beginning and the end of them) can be connected to changes in natural climate variability. These include changing sunspot numbers (as a measure of solar activity), so-called Little Ice Age Type Events (LIATEs) as well as changes in the North Atlantic Oscillation (NAO). Climate signals from external forcing factors, which could be used to explain the

  20. Air Force Seal Programs

    NASA Technical Reports Server (NTRS)

    Mayhew, Ellen R.

    1996-01-01

    Seal technology development is an important part of the Air Force's participation in the Integrated High Performance Turbine Engine Technology (IHPTET) initiative, the joint DOD, NASA, ARPA, and industry endeavor to double turbine engine capabilities by the turn of the century. Significant performance and efficiency improvements can be obtained through reducing internal flow system leakage, but seal environment requirements continue to become more extreme as the engine thermodynamic cycles advance towards these IHPTET goals. Seal technology continues to be pursued by the Air Force to control leakage at the required conditions. This presentation briefly describes current seal research and development programs and gives a summary of seal applications in demonstrator and developmental engines.

  1. Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China’s Labor-Force Dynamic Survey

    PubMed Central

    Gong, Xiao; Luo, Xiaofeng; Ling, Li

    2016-01-01

    Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women’s reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women’s risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%–46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%–36.97%)). Multivariate analysis showed that participants with a marital status of “Widowed” had statistically lower exposure rates, while those with a status of “Cohabitation” had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants’ different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS. PMID:27043604

  2. Vacuum force

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-03-01

    To study on vacuum force, we must clear what is vacuum, vacuum is a space do not have any air and also ray. There is not exist an absolute the vacuum of space. The vacuum of space is relative, so that the vacuum force is relative. There is a certain that vacuum vacuum space exists. In fact, the vacuum space is relative, if the two spaces compared to the existence of relative vacuum, there must exist a vacuum force, and the direction of the vacuum force point to the vacuum region. Any object rotates and radiates. Rotate bend radiate- centripetal, gravity produced, relative gravity; non gravity is the vacuum force. Gravity is centripetal, is a trend that the objects who attracted wants to Centripetal, or have been do Centripetal movement. Any object moves, so gravity makes the object curve movement, that is to say, the radiation range curve movement must be in the gravitational objects, gravity must be existed in non vacuum region, and make the object who is in the region of do curve movement (for example: The earth moves around the sun), or final attracted in the form gravitational objects, and keep relatively static with attract object. (for example: objects on the earth moves but can't reach the first cosmic speed).

  3. Air Force seal activities

    NASA Technical Reports Server (NTRS)

    Mayhew, Ellen R.

    1994-01-01

    Seal technology development is an important part of the Air Force's participation in the Integrated High Performance Turbine Engine Technology (IHPTET) initiative, the joint DOD, NASA, ARPA, and industry endeavor to double turbine engine capabilities by the turn of the century. Significant performance and efficiency improvements can be obtained through reducing internal flow system leakage, but seal environment requirements continue to become more extreme as the engine thermodynamic cycles advance towards these IHPTET goals. Brush seal technology continues to be pursued by the Air Force to reduce leakage at the required conditions. Likewise, challenges in engine mainshaft air/oil seals are also being addressed. Counter-rotating intershaft applications within the IHPTET initiative involve very high rubbing velocities. This viewgraph presentation briefly describes past and current seal research and development programs and gives a summary of seal applications in demonstrator and developmental engine testing.

  4. Differential force balances during levitation

    NASA Astrophysics Data System (ADS)

    Todd, Paul

    The simplest arithmetic of inertial, buoyant, magnetic and electrokinetic levitation is explored in the context of a model living system with “acceleration-sensitive structures” in which motion, if allowed, produces a biological effect. The simple model is a finite-sized object enclosed within another finite-sized object suspended in an outer fluid (liquid or vapor) medium. The inner object has density and electrical and magnetic properties quantitatively different from those of the outer object and the medium. In inertial levitation (“weightlessness”) inertial accelerations are balanced, and the forces due to them are canceled in accordance with Newton’s third law. In the presence of inertial acceleration (gravity, centrifugal) motionlessness depends on a balance between the levitating force and the inertial force. If the inner and outer objects differ in density one or the other will be subjected to an unbalanced force when one object is levitated by any other force (buoyant, magnetic, electrokinetic). The requirements for motionlessness of the internal object in the presence of a levitating force are equality of density in the case of buoyant levitation, equality of magnetic susceptibility in the case of magnetic levitation, and equality of zeta potential and dielectric constant in the case of electrokinetic levitation. Examples of internal “acceleration-sensitive structures” are cellular organelles and the organs of advanced plants and animals. For these structures fundamental physical data are important in the interpretation of the effects of forces used for levitation.

  5. Can a small-changes approach help address the obesity epidemic? A report of the Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council.

    PubMed

    Hill, James O

    2009-02-01

    The continued rise in obesity rates in most countries suggests that current programs and initiatives designed to combat obesity have not been successful in reversing the obesity epidemic. Obesity rates are increasing because of a gradual weight gain in most populations. There has been little long-term success in treating established obesity through lifestyle change, perhaps because of the large permanent changes in diet and physical activity required to keep weight off. An alternative strategy to address the obesity epidemic involves not focusing on weight loss but promoting small changes in diet and physical activity to initially prevent further weight gain. With the use of this strategy, obesity rates could first be stabilized in most populations and then, over time, decrease gradually. Supporting data show that small reductions in conscious energy intake and increases in physical activity can reduce excessive weight gain. The opportunity exists to use the small-changes approach to bring different stakeholders together to create a national initiative to address the global epidemic of obesity. The Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council believe that a small-changes framework, aimed at helping people make conscious small changes in lifestyle behaviors, in combination with efforts by the private sector to gradually "ratchet down" some of the environmental factors that have contributed to excessive energy intake and the declining rates of physical activity, can be successful in reducing obesity rates. Such an initiative would benefit from the support of educational and social marketing campaigns developed with governmental input and support. PMID:19088151

  6. Estimation of Coriolis Force and Torque Acting on Ares-1

    NASA Technical Reports Server (NTRS)

    Mackey, Ryan M.; Kulikov, Igor K.; Smelyanskiy, Vadim; Luchinsky, Dmitry; Orr, Jeb

    2011-01-01

    A document describes work on the origin of Coriolis force and estimating Coriolis force and torque applied to the Ares-1 vehicle during its ascent, based on an internal ballistics model for a multi-segmented solid rocket booster (SRB).

  7. Operating internationally

    SciTech Connect

    Seeley, R.S.

    1994-02-01

    When Enron Power Corp. took over a 28 MW power facility at the former US Naval base in Subic Bay, the Philippines, the company was required to employ 139 people to run the plant. This large labor force was necessary not because of the plant's operational needs, but because of local labor practices and unemployment pressures. Independent power companies have become all too familiar with the high cost and complexity of developing projects in emerging international markets. Some of the most significant issues involve taxation, unfamiliar legal systems, changing regulations, and foreign investment restrictions. In addition, questions about currency exchange, national credit worthiness, and political stability add to the difficulty of international development. However, one of the most daunting challenges centers not on development, but on long-term operations and maintenance (O M). A key concern is finding qualified labor. Most developers and O M companies agree that local people should run the plant, with the top person, or persons, thoroughly trained in the developer's company philosophy.

  8. Forced Migration: Refugee Populations

    PubMed Central

    Boyle, Joyceen S.

    2015-01-01

    Undocumented migration is a global phenomenon that manifests in various contexts. This article describes the impact of the movement of large numbers of people in several African countries, producing a unique type of migrant—the refugee. We describe issues that refugee movements create on fragile health care systems, situations that precipitate refugee movements, certain human rights violations that are of particular concern such as gender based violence (GBV) and child soldiers, and lastly, implications for nursing practice and policy. We use examples from several countries in Sub-Saharan Africa, including the Democratic Republic of the Congo, Rwanda, Liberia, Sierra Leone, and Mozambique. Drawing on key documents from the United Nations High Commissioner for Refugees, current literature, as well as the international experience of the authors, this article presents an overview of forced migration and discusses opportunities for nurses to impact research, practice and policy related to refugee health. PMID:25645484

  9. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  10. Knee joint forces: prediction, measurement, and significance.

    PubMed

    D'Lima, Darryl D; Fregly, Benjamin J; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W

    2012-02-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  11. HOW TO DESIGN NUTRITIONAL INTERVENTION TRIALS TO SLOW COGNITIVE DECLINE IN APPARENTLY HEALTHY POPULATIONS AND APPLY FOR EFFICACY CLAIMS: A STATEMENT FROM THE INTERNATIONAL ACADEMY ON NUTRITION AND AGING TASK FORCE

    PubMed Central

    Ferry, M.; Coley, N.; Andrieu, S.; Bonhomme, C.; Caubere, J.P.; Cesari, M.; Gautry, J.; Garcia Sanchez, I.; Hugonot, L.; Mansuy, L.; Pahor, M.; Pariente, J.; Ritz, P.; Salva, A.; Sijben, J.; Wieggers, R.; Ythier-Moury, P.; Zaim, M.; Zetlaoui, J.; Vellas, B.

    2015-01-01

    Interventions are crucial as they offer simple and inexpensive public health solutions that will be useful over the long term use. A Task Force on designing trials of nutritional interventions to slow cognitive decline in older adults was held in Toulouse in September 2012. The aim of the Task Force was to bring together leading experts from academia, the food industry and regulatory agencies to determine the best trial designs that would enable us to reach our goal of maintaining or improving cognitive function in apparently healthy aging people. An associated challenge for this Task Force was to determine the type of trials required by the Public Food Agencies for assessing the impact of nutritional compounds in comparison to well established requirements for drug trials. Although the required quality of the study design, rationale and statistical analysis remains the same, the studies designed to show reduction of cognitive decline require a long duration and the objectives of this task force was to determine best design for these trials. Two specific needs were identified to support trials of nutritional interventions: 1- Risk- reduction strategies are needed to tackle the growing burden of cognitive decline that may lead to dementia, 2- Innovative study designs are needed to improve the quality of these studies. PMID:23933873

  12. Nanonet Force Microscopy for Measuring Cell Forces.

    PubMed

    Sheets, Kevin; Wang, Ji; Zhao, Wei; Kapania, Rakesh; Nain, Amrinder S

    2016-07-12

    The influence of physical forces exerted by or felt by cells on cell shape, migration, and cytoskeleton arrangement is now widely acknowledged and hypothesized to occur due to modulation of cellular inside-out forces in response to changes in the external fibrous environment (outside-in). Our previous work using the non-electrospinning Spinneret-based Tunable Engineered Parameters' suspended fibers has revealed that cells are able to sense and respond to changes in fiber curvature and structural stiffness as evidenced by alterations to focal adhesion cluster lengths. Here, we present the development and application of a suspended nanonet platform for measuring C2C12 mouse myoblast forces attached to fibers of three diameters (250, 400, and 800 nm) representing a wide range of structural stiffness (3-50 nN/μm). The nanonet force microscopy platform measures cell adhesion forces in response to symmetric and asymmetric external perturbation in single and cyclic modes. We find that contractility-based, inside-out forces are evenly distributed at the edges of the cell, and that forces are dependent on fiber structural stiffness. Additionally, external perturbation in symmetric and asymmetric modes biases cell-fiber failure location without affecting the outside-in forces of cell-fiber adhesion. We then extend the platform to measure forces of (1) cell-cell junctions, (2) single cells undergoing cyclic perturbation in the presence of drugs, and (3) cancerous single-cells transitioning from a blebbing to a pseudopodial morphology. PMID:27410747

  13. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries: a statement for healthcare professionals from a task force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian Resuscitation Council, New Zealand Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Councils of Southern Africa).

    PubMed

    Jacobs, Ian; Nadkarni, Vinay; Bahr, Jan; Berg, Robert A; Billi, John E; Bossaert, Leo; Cassan, Pascal; Coovadia, Ashraf; D'Este, Kate; Finn, Judith; Halperin, Henry; Handley, Anthony; Herlitz, Johan; Hickey, Robert; Idris, Ahamed; Kloeck, Walter; Larkin, Gregory Luke; Mancini, Mary Elizabeth; Mason, Pip; Mears, Gregory; Monsieurs, Koenraad; Montgomery, William; Morley, Peter; Nichol, Graham; Nolan, Jerry; Okada, Kazuo; Perlman, Jeffrey; Shuster, Michael; Steen, Petter Andreas; Sterz, Fritz; Tibballs, James; Timerman, Sergio; Truitt, Tanya; Zideman, David

    2004-11-23

    Outcome after cardiac arrest and cardiopulmonary resuscitation is dependent on critical interventions, particularly early defibrillation, effective chest compressions, and advanced life support. Utstein-style definitions and reporting templates have been used extensively in published studies of cardiac arrest, which has led to greater understanding of the elements of resuscitation practice and progress toward international consensus on science and resuscitation guidelines. Despite the development of Utstein templates to standardize research reports of cardiac arrest, international registries have yet to be developed. In April 2002, a task force of the International Liaison Committee on Resuscitation (ILCOR) met in Melbourne, Australia, to review worldwide experience with the Utstein definitions and reporting templates. The task force revised the core reporting template and definitions by consensus. Care was taken to build on previous definitions, changing data elements and operational definitions only on the basis of published data and experience derived from those registries that have used Utstein-style reporting. Attention was focused on decreasing the complexity of the existing templates and addressing logistical difficulties in collecting specific core and supplementary (ie, essential and desirable) data elements recommended by previous Utstein consensus conferences. Inconsistencies in terminology between in-hospital and out-of-hospital Utstein templates were also addressed. The task force produced a reporting tool for essential data that can be used for both quality improvement (registries) and research reports and that should be applicable to both adults and children. The revised and simplified template includes practical and succinct operational definitions. It is anticipated that the revised template will enable better and more accurate completion of all reports of cardiac arrest and resuscitation attempts. Problems with data definition, collection, linkage

  14. Transnational Research Collaboration. A Report Submitted by the Task Force on Transnational Collaborative Research to the Government/Academic Interface Committee, International Education Project, American Council on Education. Occasional Paper No. 2.

    ERIC Educational Resources Information Center

    Mangone, Gerard J.; And Others

    A descriptive overview of international, cooperative research efforts is provided. Transnational collaborative research consists of those activities that bring scholars of different countries together to work on the same or common research problems that cannot be addressed as effectively by an individual nation. This report offers a sampling of…

  15. Force regulation in multiple-manipulator systems

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Murphy, Steve H.

    1992-01-01

    A new intuitively appealing interpretation of the internal force in a multiple-arm system is presented. The static gravity-free case is considered where internal force has a well-founded physical meaning. The case is extended to the general dynamic case by removing the inertial force through balancing it with the minimum amount of contact force. The remaining component in the contact force is considered to be the sole contributor to the inertial force. Existing techniques for force control can be used to obtain various stabilizing force set point control laws. Particular attention is given to the motion control strategy for multiple arm systems. Three types of control laws, feedback linearization, arms-as-actuators, and passive control, are addressed. The first two techniques provide simplified control tuning but require much model information. The latter approach is considered to be very robust with respect to the model, but good transient performance is more challenging to obtain. It is suggested to combine one of the model-based approaches with the passive control approach.

  16. Forced-flow planar chromatography in the rear view mirror.

    PubMed

    Kalász, Huba

    2015-03-01

    Mobile phase progress in planar stationary phase can be evoked by either external or internal forces. An internal force is capillarity, while gravity, electric field, a pump and centrifugal forces belong to external forces. Overpressured layer chromatography gives a widely used special chapter of forced-flow planar chromatography, a special bridge between high-performance liquid column chromatography and thin-layer chromatography (TLC). A simple and special rule characterizes the progress of mobile phase. Optimal efficiency is composed by the doubled effect of flow resulting from the pump-forced mobile phase (convex profile of laminar flow) and capillary forces on the dry stationary phase (concave laminar flow). This review describes the most important aspects of forced-flow TLC, including how the set-ups are developed and also the progress of detection methods used. PMID:25681205

  17. Aerodynamic Lifting Force.

    ERIC Educational Resources Information Center

    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)

  18. Fluid force transducer

    DOEpatents

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  19. Physicists' Forced Migrations under Hitler

    NASA Astrophysics Data System (ADS)

    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.

  20. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries. A statement for healthcare professionals from a task force of the international liaison committee on resuscitation (American Heart Association, European Resuscitation Council, Australian Resuscitation Council, New Zealand Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa).

    PubMed

    Jacobs, Ian; Nadkarni, Vinay; Bahr, Jan; Berg, Robert A; Billi, John E; Bossaert, Leo; Cassan, Pascal; Coovadia, Ashraf; D'Este, Kate; Finn, Judith; Halperin, Henry; Handley, Anthony; Herlitz, Johan; Hickey, Robert; Idris, Ahamed; Kloeck, Walter; Larkin, Gregory Luke; Mancini, Mary Elizabeth; Mason, Pip; Mears, Gregory; Monsieurs, Koenraad; Montgomery, William; Morley, Peter; Nichol, Graham; Nolan, Jerry; Okada, Kazuo; Perlman, Jeffrey; Shuster, Michael; Steen, Petter Andreas; Sterz, Fritz; Tibballs, James; Timerman, Sergio; Truitt, Tanya; Zideman, David

    2004-12-01

    Outcome following cardiac arrest and cardiopulmonary resuscitation is dependent on critical interventions, particularly early defibrillation, effective chest compressions, and advanced life support. Utstein-style definitions and reporting templates have been used extensively in published studies of cardiac arrest, which has led to greater understanding of the elements of resuscitation practice and progress toward international consensus on science and resuscitation guidelines. Despite the development of Utstein templates to standardize research reports of cardiac arrest, international registries have yet to be developed. In April 2002 a task force of ILCOR met in Melbourne, Australia, to review worldwide experience with the Utstein definitions and reporting templates. The task force revised the core reporting template and definitions by consensus. Care was taken to build on previous definitions, changing data elements and operational definitions only on the basis of published data and experience derived from those registries that have used Utstein-style reporting. Attention was focused on decreasing the complexity of the existing templates and addressing logistical difficulties in collecting specific core and supplementary (i.e., essential and desirable) data elements recommended by previous Utstein consensus conference. Inconsistencies in terminology between in-hospital and out-of-hospital Utstein templates were also addressed. The task force produced a reporting tool for essential data that can be used for both quality improvement (registries) and research reports and that should be applicable to both adults and children. The revised and simplified template includes practical and succinct operational definitions. It is anticipated that the revised template will enable better and more accurate completion of all reports of cardiac arrest and resuscitation attempts. Problems with data definition, collection, linkage, confidentiality, management, and registry

  1. Reply to ``Electrodynamic force law controversy''

    NASA Astrophysics Data System (ADS)

    Cavalleri, G.; Tonni, E.; Spavieri, G.

    2001-05-01

    Our paper [Phys. Rev. E 58, 2505 (1998)] confirmed the validity of both Ampère and Grassmann's force law even for the action exerted on a part of a current loop. Since that part can be an element of a circuit, both force laws also predict the same internal stresses and the same recoil for a railgun. Graneau and Graneau [preceding paper, Phys. Rev. E 63, 058601 (2001)] neglected the action on the breech of the railgun, an action that produces the same recoil for both force laws. The reaction to the force exerted on the armature does not act on the rails but on the breech that, simply because of symmetry, undergoes a force equal and opposite to the one acting on the armature.

  2. Crossflow force transducer. [LMFBR

    SciTech Connect

    Mulcahy, T M

    1982-05-01

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related.

  3. Debunking Coriolis Force Myths

    ERIC Educational Resources Information Center

    Shakur, Asif

    2014-01-01

    Much has been written and debated about the Coriolis force. Unfortunately, this has done little to demystify the paradoxes surrounding this fictitious force invoked by an observer in a rotating frame of reference. It is the purpose of this article to make another valiant attempt to slay the dragon of the Coriolis force! This will be done without…

  4. Forces in General Relativity

    ERIC Educational Resources Information Center

    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…

  5. How weather impacts the forced climate response

    SciTech Connect

    Kirtman, Ben P.; Schneider, Edwin K.; Straus, David M.; Min, Dughong; Burgman, Robert

    2011-05-10

    The new interactive ensemble modeling strategy is used to diagnose how noise due to internal atmospheric dynamics impacts the forced climate response during the twentieth century (i.e., 1870–1999). The interactive ensemble uses multiple realizations of the atmospheric component model coupled to a single realization of the land, ocean and ice component models in order to reduce the noise due to internal atmospheric dynamics in the flux exchange at the interface of the component models. A control ensemble of so-called climate of the twentieth century simulations of the Community Climate Simulation Model version 3 (CCSM3) are compared with a similar simulation with the interactive ensemble version of CCSM3. Despite substantial differences in the overall mean climate, the global mean trends in surface temperature, 500 mb geopotential and precipitation are largely indistinguishable between the control ensemble and the interactive ensemble. Large differences in the forced response; however, are detected particularly in the surface temperature of the North Atlantic. Associated with the forced North Atlantic surface temperature differences are local differences in the forced precipitation and a substantial remote rainfall response in the deep tropical Pacific. We also introduce a simple variance analysis to separately compare the variance due to noise and the forced response. We find that the noise variance is decreased when external forcing is included. Finally, in terms of the forced variance, we find that the interactive ensemble increases this variance relative to the control.

  6. Temperature Management After Cardiac Arrest: An Advisory Statement by the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation and the American Heart Association Emergency Cardiovascular Care Committee and the Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation.

    PubMed

    Donnino, Michael W; Andersen, Lars W; Berg, Katherine M; Reynolds, Joshua C; Nolan, Jerry P; Morley, Peter T; Lang, Eddy; Cocchi, Michael N; Xanthos, Theodoros; Callaway, Clifton W; Soar, Jasmeet

    2015-12-22

    For more than a decade, mild induced hypothermia (32 °C-34 °C) has been standard of care for patients remaining comatose after resuscitation from out-of-hospital cardiac arrest with an initial shockable rhythm, and this has been extrapolated to survivors of cardiac arrest with initially nonshockable rhythms and to patients with in-hospital cardiac arrest. Two randomized trials published in 2002 reported a survival and neurological benefit with mild induced hypothermia. One recent randomized trial reported similar outcomes in patients treated with targeted temperature management at either 33 °C or 36 °C. In response to these new data, the International Liaison Committee on Resuscitation Advanced Life Support Task Force performed a systematic review to evaluate 3 key questions: (1) Should mild induced hypothermia (or some form of targeted temperature management) be used in comatose post-cardiac arrest patients? (2) If used, what is the ideal timing of the intervention? (3) If used, what is the ideal duration of the intervention? The task force used Grading of Recommendations Assessment, Development and Evaluation methodology to assess and summarize the evidence and to provide a consensus on science statement and treatment recommendations. The task force recommends targeted temperature management for adults with out-of-hospital cardiac arrest with an initial shockable rhythm at a constant temperature between 32 °C and 36 °C for at least 24 hours. Similar suggestions are made for out-of-hospital cardiac arrest with a nonshockable rhythm and in-hospital cardiac arrest. The task force recommends against prehospital cooling with rapid infusion of large volumes of cold intravenous fluid. Additional and specific recommendations are provided in the document. PMID:26434495

  7. Temperature Management After Cardiac Arrest: An Advisory Statement by the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation and the American Heart Association Emergency Cardiovascular Care Committee and the Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation.

    PubMed

    Donnino, Michael W; Andersen, Lars W; Berg, Katherine M; Reynolds, Joshua C; Nolan, Jerry P; Morley, Peter T; Lang, Eddy; Cocchi, Michael N; Xanthos, Theodoros; Callaway, Clifton W; Soar, Jasmeet

    2016-01-01

    For more than a decade, mild induced hypothermia (32 °C-34 °C) has been standard of care for patients remaining comatose after resuscitation from out-of-hospital cardiac arrest with an initial shockable rhythm, and this has been extrapolated to survivors of cardiac arrest with initially nonshockable rhythms and to patients with in-hospital cardiac arrest. Two randomized trials published in 2002 reported a survival and neurological benefit with mild induced hypothermia. One recent randomized trial reported similar outcomes in patients treated with targeted temperature management at either 33 °C or 36 °C. In response to these new data, the International Liaison Committee on Resuscitation Advanced Life Support Task Force performed a systematic review to evaluate 3 key questions: (1) Should mild induced hypothermia (or some form of targeted temperature management) be used in comatose post-cardiac arrest patients? (2) If used, what is the ideal timing of the intervention? (3) If used, what is the ideal duration of the intervention? The task force used Grading of Recommendations Assessment, Development and Evaluation methodology to assess and summarize the evidence and to provide a consensus on science statement and treatment recommendations. The task force recommends targeted temperature management for adults with out-of-hospital cardiac arrest with an initial shockable rhythm at a constant temperature between 32 °C and 36 °C for at least 24 hours. Similar suggestions are made for out-of-hospital cardiac arrest with a nonshockable rhythm and in-hospital cardiac arrest. The task force recommends against prehospital cooling with rapid infusion of large volumes of cold intravenous fluid. Additional and specific recommendations are provided in the document. PMID:26449873

  8. Citizen groups: a creative force

    SciTech Connect

    Stoel, T.

    1981-02-01

    The role of citizen groups is as important as that of government agencies when it comes to environmental policy in a democracy. These groups spend little money, yet they have initiated the major US environmental legislation of the past two decades. They are a recent, but effective, force in developing countries even though adversarial approaches are not often appropriate. The methods used by US environmental groups range from lobbying to confrontation in court. Groups outside the US tend to use consensus in democracies and information gathering in developing countries. While the groups' primary concerns are national in scope, international awareness and cooperation are growing. (DCK)

  9. Quarkonium binding and entropic force

    NASA Astrophysics Data System (ADS)

    Satz, Helmut

    2015-05-01

    A bound state represents a balance between repulsive kinetic and attractive potential energy. In a hot quark-gluon plasma, the interaction potential experiences medium effects. Color screening modifies the attractive binding force between the quarks, while the increase of entropy with separation gives rise to a growing repulsion. We study the role of these phenomena for in-medium binding and dissociation. It is found that the relevant potential for binding is the free energy ; with increasing separation, further binding through the internal energy is compensated by repulsive entropic effects.

  10. Cell adhesion force microscopy

    PubMed Central

    Sagvolden, G.; Giaever, I.; Pettersen, E. O.; Feder, J.

    1999-01-01

    The adhesion forces of cervical carcinoma cells in tissue culture were measured by using the manipulation force microscope, a novel atomic force microscope. The forces were studied as a function of time and temperature for cells cultured on hydrophilic and hydrophobic polystyrene substrates with preadsorbed proteins. The cells attached faster and stronger at 37°C than at 23°C and better on hydrophilic than on hydrophobic substrates, even though proteins adsorb much better to the hydrophobic substrates. Because cell adhesion serves to control several stages in the cell cycle, we anticipate that the manipulation force microscope can help clarify some cell-adhesion related issues. PMID:9892657

  11. Efficacy of climate forcings

    NASA Astrophysics Data System (ADS)

    Hansen, J.; Sato, M.; Ruedy, R.; Nazarenko, L.; Lacis, A.; Schmidt, G. A.; Russell, G.; Aleinov, I.; Bauer, M.; Bauer, S.; Bell, N.; Cairns, B.; Canuto, V.; Chandler, M.; Cheng, Y.; Del Genio, A.; Faluvegi, G.; Fleming, E.; Friend, A.; Hall, T.; Jackman, C.; Kelley, M.; Kiang, N.; Koch, D.; Lean, J.; Lerner, J.; Lo, K.; Menon, S.; Miller, R.; Minnis, P.; Novakov, T.; Oinas, V.; Perlwitz, Ja.; Perlwitz, Ju.; Rind, D.; Romanou, A.; Shindell, D.; Stone, P.; Sun, S.; Tausnev, N.; Thresher, D.; Wielicki, B.; Wong, T.; Yao, M.; Zhang, S.

    2005-09-01

    We use a global climate model to compare the effectiveness of many climate forcing agents for producing climate change. We find a substantial range in the "efficacy" of different forcings, where the efficacy is the global temperature response per unit forcing relative to the response to CO2 forcing. Anthropogenic CH4 has efficacy ˜110%, which increases to ˜145% when its indirect effects on stratospheric H2O and tropospheric O3 are included, yielding an effective climate forcing of ˜0.8 W/m2 for the period 1750-2000 and making CH4 the largest anthropogenic climate forcing other than CO2. Black carbon (BC) aerosols from biomass burning have a calculated efficacy ˜58%, while fossil fuel BC has an efficacy ˜78%. Accounting for forcing efficacies and for indirect effects via snow albedo and cloud changes, we find that fossil fuel soot, defined as BC + OC (organic carbon), has a net positive forcing while biomass burning BC + OC has a negative forcing. We show that replacement of the traditional instantaneous and adjusted forcings, Fi and Fa, with an easily computed alternative, Fs, yields a better predictor of climate change, i.e., its efficacies are closer to unity. Fs is inferred from flux and temperature changes in a fixed-ocean model run. There is remarkable congruence in the spatial distribution of climate change, normalized to the same forcing Fs, for most climate forcing agents, suggesting that the global forcing has more relevance to regional climate change than may have been anticipated. Increasing greenhouse gases intensify the Hadley circulation in our model, increasing rainfall in the Intertropical Convergence Zone (ITCZ), Eastern United States, and East Asia, while intensifying dry conditions in the subtropics including the Southwest United States, the Mediterranean region, the Middle East, and an expanding Sahel. These features survive in model simulations that use all estimated forcings for the period 1880-2000. Responses to localized forcings, such

  12. INTERNAL CUTTING DEVICE

    DOEpatents

    Russell, W.H. Jr.

    1959-06-30

    A device is described for removing material from the interior of a hollow workpiece so as to form a true spherical internal surface in a workpiece, or to cut radial slots of an adjustable constant depth in an already established spherical internal surface. This is accomplished by a spring loaded cutting tool adapted to move axially wherein the entire force urging the tool against the workpiece is derived from the spring. Further features of importance involve the provision of a seal between the workpiece and the cutting device and a suction device for carrying away particles of removed material.

  13. A White Paper on the medical and social needs of people with epilepsy and intellectual disability: the Task Force on Intellectual Disabilities and Epilepsy of the International League Against Epilepsy.

    PubMed

    Kerr, Mike; Linehan, Christine; Thompson, Rose; Mula, Marco; Gil-Nagal, Antonio; Zuberi, Sameer M; Glynn, Mike

    2014-12-01

    This White Paper builds on the publication of the International League Against Epilepsy (ILAE) and International Bureau for Epilepsy (IBE) report "Listening for a change-medical and social needs of people with intellectual disability who have epilepsy" (Listening for a change the medical and social needs of people with epilepsy and intellectual disability, ILAE, 2013). The Paper presents an overview of the recommendations of the report, which aim to improve the health and social care of this important population of people with epilepsy worldwide. Actions in four domains are indicated: (1) the development of standards and initiatives that would enhance diagnosis, pathways to investigation, and treatment; (2) the development of guidelines for treatment, specifically best practice in the management of antiepileptic drugs including rescue medication; (3) the development of standards for primary care, multidisciplinary teamwork, and clinical consultations, with emphasis on the need to enhance communication and improve access to information; and (4) the enhancement of links among different stakeholders including medical services, educational establishments, employment services, organizations providing opportunities for social engagement, and family members. The breadth of needs of this population is a challenge to the epilepsy world, spanning all the professional groupings, care providers, and the research modalities in epilepsy. PMID:25378101

  14. Forces in molecules.

    PubMed

    Hernández-Trujillo, Jesús; Cortés-Guzmán, Fernando; Fang, De-Chai; Bader, Richard F W

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another? PMID:17328425

  15. Force Limited Vibration Testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry; Chang, Kurng Y.

    2005-01-01

    This slide presentation reviews the concept and applications of Force Limited Vibration Testing. The goal of vibration testing of aerospace hardware is to identify problems that would result in flight failures. The commonly used aerospace vibration tests uses artificially high shaker forces and responses at the resonance frequencies of the test item. It has become common to limit the acceleration responses in the test to those predicted for the flight. This requires an analysis of the acceleration response, and requires placing accelerometers on the test item. With the advent of piezoelectric gages it has become possible to improve vibration testing. The basic equations have are reviewed. Force limits are analogous and complementary to the acceleration specifications used in conventional vibration testing. Just as the acceleration specification is the frequency spectrum envelope of the in-flight acceleration at the interface between the test item and flight mounting structure, the force limit is the envelope of the in-flight force at the interface . In force limited vibration tests, both the acceleration and force specifications are needed, and the force specification is generally based on and proportional to the acceleration specification. Therefore, force limiting does not compensate for errors in the development of the acceleration specification, e.g., too much conservatism or the lack thereof. These errors will carry over into the force specification. Since in-flight vibratory force data are scarce, force limits are often derived from coupled system analyses and impedance information obtained from measurements or finite element models (FEM). Fortunately, data on the interface forces between systems and components are now available from system acoustic and vibration tests of development test models and from a few flight experiments. Semi-empirical methods of predicting force limits are currently being developed on the basis of the limited flight and system test

  16. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....112-1 Combat zone compensation of members of the Armed Forces. (a) Combat zone compensation exclusion... excludes from gross income the following compensation of members of the Armed Forces: (i)...

  17. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....112-1 Combat zone compensation of members of the Armed Forces. (a) Combat zone compensation exclusion... excludes from gross income the following compensation of members of the Armed Forces: (i)...

  18. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....112-1 Combat zone compensation of members of the Armed Forces. (a) Combat zone compensation exclusion... excludes from gross income the following compensation of members of the Armed Forces: (i)...

  19. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....112-1 Combat zone compensation of members of the Armed Forces. (a) Combat zone compensation exclusion... excludes from gross income the following compensation of members of the Armed Forces: (i)...

  20. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....112-1 Combat zone compensation of members of the Armed Forces. (a) Combat zone compensation exclusion... excludes from gross income the following compensation of members of the Armed Forces: (i)...

  1. Benefits of Force Limiting Vibration Testing

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Scharton, Terry D.

    1999-01-01

    Force limited random vibration testing is used at NASA John Glenn Research Center (formerly NASA Lewis Research Center) for qualifying aerospace hardware for flight. The benefit of force limiting testing is that it limits overtesting of flight hardware, by controlling input force and acceleration from the shaker (dual control) to the test article. The purpose of force limiting is to replicate the test article resonant response for the actual flight mounting condition. The force limiting testing technology has been implemented at the Jet Propulsion Laboratory for the past 10 years on various spacecraft testing programs. The Cassini mission to Saturn, most notably, utilized force limiting vibration testing as part of the spacecraft system level vibration testing. NASA John Glenn Research Center is responsible for microgravity combustion and fluid science research on the Shuttle and the International Space Station. Qualification testing of delicate and vibration sensitive science instrumentation is particularly challenging to successfully qualify for flight. In order to facilitate the testing process, force limiting has been implemented to minimize overtesting of flight hardware. This paper will address recent flight camera testing (qualification random vibration and strength testing) for the Combustion Module-2 mission and the impact of Semi-empirical Method force limits.

  2. Coulomb force as an entropic force

    NASA Astrophysics Data System (ADS)

    Wang, Tower

    2010-05-01

    Motivated by Verlinde’s theory of entropic gravity, we give a tentative explanation to the Coulomb’s law with an entropic force. When trying to do this, we find the equipartition rule should be extended to charges and the concept of temperature should be reinterpreted. If one accepts the holographic principle as well as our generalizations and reinterpretations, then Coulomb’s law, the Poisson equation, and the Maxwell equations can be derived smoothly. Our attempt can be regarded as a new way to unify the electromagnetic force with gravity, from the entropic origin. Possibly some of our postulates are related to the D-brane picture of black hole thermodynamics.

  3. Coulomb force as an entropic force

    SciTech Connect

    Wang Tower

    2010-05-15

    Motivated by Verlinde's theory of entropic gravity, we give a tentative explanation to the Coulomb's law with an entropic force. When trying to do this, we find the equipartition rule should be extended to charges and the concept of temperature should be reinterpreted. If one accepts the holographic principle as well as our generalizations and reinterpretations, then Coulomb's law, the Poisson equation, and the Maxwell equations can be derived smoothly. Our attempt can be regarded as a new way to unify the electromagnetic force with gravity, from the entropic origin. Possibly some of our postulates are related to the D-brane picture of black hole thermodynamics.

  4. International Cooperation at NASA

    NASA Astrophysics Data System (ADS)

    Tawney, Timothy; Feldstein, Karen

    International cooperation is a cornerstone principle of NASA’s activities, especially within the activities of the Science Mission Directorate. Nearly two thirds of the flight missions in which NASA leads or participates involve international cooperation. Numerous ground based activities also rely on international cooperation, whether because of unique expertise, unique geography, or the need for a global response. Going forward, in an era of tighter budgets and a more integrated global perspective, NASA and the rest of the space agencies around the world will be forced to work more closely together, in a broader array of activities than ever before, in order to be able to afford to push the boundaries of space exploration. The goal of this presentation is to provide an overview of NASA’s current international science cooperative activities. It will include a discussion of why NASA conducts international cooperation and look at the mechanisms through which international cooperation can occur at NASA, including peer-to-peer development of relationships. It will also discuss some of the limiting factors of international cooperation, such as export control, and ways in which to manage those constraints. Finally, the presentation would look at some of the present examples where NASA is working to increase international cooperation and improve coordination. Case studies will be used to demonstrate these mechanisms and concepts. For example, NASA continues to participate in international coordination groups such as the International Mars Exploration Working Group (IMEWG) and International Space Exploration Coordination Group (ISECG), but is expanding into new areas as well. NASA is one of the leaders in expanding and improving international coordination in the area of Near-Earth Object detection, characterization, and mitigation. Having participated in the first meetings of such groups as the International Asteroid Warning Network (IAWN) and Space Missions Planning

  5. U.S. Transport Task Force 2010

    SciTech Connect

    Diamond, P.H.

    2011-09-21

    The Transport Task Force (TTF) Meeting is a venue for vigorous scientific discourse and discussion on topics in transport and turbulence in fusion plasmas. Its participation is international. The 2010 meeting was highly effective, with 139 registered participants and 131 presentations. This is remarkable for an even year (IAEA year) meeting. The meeting clearly fostered progress in understanding and control of turbulent transport.

  6. NII Task Force Issues Preliminary Report.

    ERIC Educational Resources Information Center

    Bulletin of the American Society for Information Science, 1994

    1994-01-01

    Presents the preliminary report of the National Information Infrastructure's Task Force on Intellectual Property. Topics addressed include current copyright law; distribution rights; publication; first sale doctrine; technological protection; copyright management information; public performance right; fair use; licensing; international issues;…

  7. Debunking Coriolis Force Myths

    NASA Astrophysics Data System (ADS)

    Shakur, Asif

    2014-11-01

    Much has been written and debated about the Coriolis force.1-8 Unfortunately, this has done little to demystify the paradoxes surrounding this fictitious force invoked by an observer in a rotating frame of reference. It is the purpose of this article to make another valiant attempt to slay the dragon of the Coriolis force! This will be done without unleashing the usual mathematical apparatus, which we believe is more of a hindrance than a help.

  8. Lathe tool force

    SciTech Connect

    Emery, J.D.

    1993-02-01

    This report describes a computer program that computes the forces exerted on a lathe tool as a part is being machined. The program is based on a mechanistic model which assumes that the normal force on the tool face is proportional to the cross-sectional area of the chip that is being removed from the part. This report gives transcripts of program runs, a comparison with experimentally measured forces, a bibliography, and a listing of the program.

  9. Relativistic Linear Restoring Force

    ERIC Educational Resources Information Center

    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…

  10. Mechanotransduction: use the force(s).

    PubMed

    Paluch, Ewa K; Nelson, Celeste M; Biais, Nicolas; Fabry, Ben; Moeller, Jens; Pruitt, Beth L; Wollnik, Carina; Kudryasheva, Galina; Rehfeldt, Florian; Federle, Walter

    2015-01-01

    Mechanotransduction - how cells sense physical forces and translate them into biochemical and biological responses - is a vibrant and rapidly-progressing field, and is important for a broad range of biological phenomena. This forum explores the role of mechanotransduction in a variety of cellular activities and highlights intriguing questions that deserve further attention. PMID:26141078

  11. No fifth force?

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    Hopes that geophysicists might be able to document a fifth force of nature have diminished, as new measurements and analyses of earlier geodetic experiments have yielded no solid evidence of a non-Newtonian component of gravity.Modern physics recognizes four fundamental forces with distinct spheres of influence: The strong and weak nuclear forces operate over the range of one atom, while gravity and electromagnetism have an infinite range. Gravity measurements over a few centimeters in laboratories and over millions of kilometers in space continue to buttress Issac Newton's conclusion that the gravitational force between two objects decreases as the square of the distance between them.

  12. Finding the Effective Mass and Spring Constant of a Force Probe from Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Greene, Nathaniel R.; Gill, Tom; Eyerly, Stephen

    2016-01-01

    Force probes are versatile tools in the physics lab, but their internal workings can introduce artifacts when measuring rapidly changing forces. The Dual-Range Force Sensor by Vernier uses strain gage technology to measure force, based on the bending of a beam. Strain gages along the length of the beam change resistance as the beam bends. The…

  13. On the 5D Extra-Force according to Basini Capozziello Ponce De Leon Formalism and five important features: Kar Sinha Gravitational Bending of Light, Chung Freese Superluminal Behaviour, Maartens Clarkson Black Strings, experimental measures of Extra Dimensions on board International Space Station (ISS) and the existence of the Particle Z due to a higher dimensional spacetime

    NASA Astrophysics Data System (ADS)

    Loup, Fernando

    2006-10-01

    We use the Conformal Metric as described in Kar Sinha work on Gravitational Bending of Light in a 5 D Spacetime to recompute the equations of the 5 D Force in Basini Capozziello Ponce De Leon Formalism and we arrive at a result that possesses some advantages. The equations of the Extra Force as proposed by Ponce De Leon are now more elegant in Conformal Formalism and many algebraic terms can be simplified or even suppressed. Also we recompute the Kar Sinha Gravitational Bending of Light affected by the presence of the Extra Dimension and analyze the Superluminal Chung Freese Features of this Formalism describing the advantages of the Chung Freese BraneWorld when compared to other Superluminal spacetime metrics (e.g. Warp Drive) and we describe why the Extra Dimension is invisible and how the Extra Dimension could be made visible at least in theory. We also examine the Maartens Clarkson Black Holes in 5 D (Black Strings) coupled to massive Kaluza Klein graviton modes predicted by Extra Dimensions theories and we study experimental detection of Extra Dimensions on-board LIGO and LISA Space Telescopes. We also propose the use of International Space Station (ISS) to measure the additional terms (resulting from the presence of Extra Dimensions) in the Kar Sinha Gravitational Bending of Light in Outer Space to verify if we really lives in a Higher Dimensional Spacetime. Also we demonstrate that Particle Z can only exist if the 5 D spacetime exists.

  14. Climate forcings and feedbacks

    NASA Technical Reports Server (NTRS)

    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

  15. The Labour Market as the Driving Force of Belgian Higher Education.

    ERIC Educational Resources Information Center

    Wielemans, Willy

    1988-01-01

    An examination of internal and external forces on Belgian higher education suggests that the system is too closely controlled by economic and political forces in the labor market, which threatens to distort university life and higher education in general. (MSE)

  16. Forces in yeast flocculation

    PubMed Central

    El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Flos, Marta Abellán; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

    2014-01-01

    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. PMID:25515338

  17. SCM-Forcing Data

    DOE Data Explorer

    Xie, Shaocheng; Tang,Shuaiqi; Zhang,Yunyan; Zhang,Minghua

    2016-07-01

    Single-Column Model (SCM) Forcing Data are derived from the ARM facility observational data using the constrained variational analysis approach (Zhang and Lin 1997 and Zhang et al., 2001). The resulting products include both the large-scale forcing terms and the evaluation fields, which can be used for driving the SCMs and Cloud Resolving Models (CRMs) and validating model simulations.

  18. Elementary Particles and Forces.

    ERIC Educational Resources Information Center

    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…

  19. Forces in yeast flocculation

    NASA Astrophysics Data System (ADS)

    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.

  20. Force Concept Inventory.

    ERIC Educational Resources Information Center

    Hestenes, David; And Others

    1992-01-01

    Reports the rationale, design, validation, and uses of the "Force Concept Inventory," an instrument to assess the students' beliefs on force. Includes results and implications of two studies that compared the inventory with the "Mechanics Baseline." Includes a copy of the instrument. (MDH)

  1. Lorentz force velocimetry.

    PubMed

    Thess, A; Votyakov, E V; Kolesnikov, Y

    2006-04-28

    We describe a noncontact technique for velocity measurement in electrically conducting fluids. The technique, which we term Lorentz force velocimetry (LFV), is based on exposing the fluid to a magnetic field and measuring the drag force acting upon the magnetic field lines. Two series of measurements are reported, one in which the force is determined through the angular velocity of a rotary magnet system and one in which the force on a fixed magnet system is measured directly. Both experiments confirm that the measured signal is a linear function of the flow velocity. We then derive the scaling law that relates the force on a localized distribution of magnetized material to the velocity of an electrically conducting fluid. This law shows that LFV, if properly designed, has a wide range of potential applications in metallurgy, semiconductor crystal growth, and glass manufacturing. PMID:16712237

  2. Feeble forces and gravity.

    NASA Astrophysics Data System (ADS)

    Bars, Itzhak; Visser, Matt

    1987-03-01

    We develop a scenario in which feeble intermediate range forces emerge as an effect resulting from the compactification (à la Kaluza-Klein) of multidimensional theories. These feeble forces compete with gravity and in general permit different bodies to fall to earth with different accelerations. We show that these feeble forces are mediated by vectors (V) and/or scalars (S), whose dimensionless coupling constants are typically of order gv ≈ gs ≈ 10-10 Under certain plausible assumptions the ranges of these feeble forces are expected to be of order 1 m to 1 km. It is conjectured that the general strategy will prove applicable to realistic multidimensional theories such as the 10-dimensional superstring theories. We speculate that deviations from the standard gravitational force-similar to the ones reported recently as a “fifth force”-may be interpreted as evidence for higher dimensions.

  3. Conservative entropic forces

    NASA Astrophysics Data System (ADS)

    Visser, Matt

    2011-10-01

    Entropic forces have recently attracted considerable attention as ways to reformulate, retrodict, and perhaps even "explain" classical Newtonian gravity from a rather specific thermodynamic perspective. In this article I point out that if one wishes to reformulate classical Newtonian gravity in terms of an entropic force, then the fact that Newtonian gravity is described by a conservative force places significant constraints on the form of the entropy and temperature functions. (These constraints also apply to entropic reinterpretations of electromagnetism, and indeed to any conservative force derivable from a potential.) The constraints I will establish are sufficient to present real and significant problems for any reasonable variant of Verlinde's entropic gravity proposal, though for technical reasons the constraints established herein do not directly impact on either Jacobson'sor Padmanabhan's versions of entropic gravity. In an attempt to resolve these issues, I will extend the usual notion of entropic force to multiple heat baths with multiple "temperatures" and multiple "entropies".

  4. International Perspectives.

    ERIC Educational Resources Information Center

    Allen, Kenn; Habermann, Ulla; Chowdhury, Omar Faruque; Guerra, Iraida Manzanilla

    1998-01-01

    Includes "Introduction to International Perspectives" (Allen); "Volunteerism in the Welfare State: The Case of Denmark" (Habermann); "Grassroots Organizing in Bangladesh" (Chowdhury); and "Volunteerism in Latin America" (Guerra). (SK)

  5. Linearly Forced Isotropic Turbulence

    NASA Technical Reports Server (NTRS)

    Lundgren, T. S.

    2003-01-01

    Stationary isotropic turbulence is often studied numerically by adding a forcing term to the Navier-Stokes equation. This is usually done for the purpose of achieving higher Reynolds number and longer statistics than is possible for isotropic decaying turbulence. It is generally accepted that forcing the Navier-Stokes equation at low wave number does not influence the small scale statistics of the flow provided that there is wide separation between the largest and smallest scales. It will be shown, however, that the spectral width of the forcing has a noticeable effect on inertial range statistics. A case will be made here for using a broader form of forcing in order to compare computed isotropic stationary turbulence with (decaying) grid turbulence. It is shown that using a forcing function which is directly proportional to the velocity has physical meaning and gives results which are closer to both homogeneous and non-homogeneous turbulence. Section 1 presents a four part series of motivations for linear forcing. Section 2 puts linear forcing to a numerical test with a pseudospectral computation.

  6. Turbomachinery rotor forces

    NASA Technical Reports Server (NTRS)

    Arndt, Norbert

    1988-01-01

    The fluid-induced forces, both steady and unsteady, acting upon an impeller of a centrifugal pump, and impeller blade-diffuser vane interaction in centrifugal pumps with vaned radial diffusers were evaluated experimentally and theoretically. Knowledge of the steady and unsteady forces, and the associated rotordynamic coefficients are required to effectively model the rotor dynamics of the High Pressure Fuel Turbopump (HPFTP) of the Space Shuttle Main Engine (SSME). These forces and rotordynamic coefficients were investigated using different impellers in combination with volutes and vaned diffusers, and axial inducers. These rotor forces are global. Local forces and pressures are also important in impeller-diffuser interaction, for they may cause cavitation damage and even vane failures. Thus, in a separate investigation, impeller wake, and impeller blade and diffuser vane pressure measurements were made. The nature of the rotordynamic forces is discussed, the experimental facility is described, and the measurements of unsteady forces and pressure are reported together with a brief and incomplete attempt to calculate these flows.

  7. OOTW Force Design Tools

    SciTech Connect

    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.

  8. Manual discrimination of force

    NASA Technical Reports Server (NTRS)

    Pang, Xiao-Dong; Tan, HONG-Z.; Durlach, Nathaniel I.

    1991-01-01

    Optimal design of human-machine interfaces for teleoperators and virtual-environment systems which involve the tactual and kinesthetic modalities requires knowledge of the human's resolving power in these modalities. The resolution of the interface should be appropriately matched to that of the human operator. We report some preliminary results on the ability of the human hand to distinguish small differences in force under a variety of conditions. Experiments were conducted on force discrimination with the thumb pushing an interface that exerts a constant force over the pushing distance and the index finger pressing against a fixed support. The dependence of the sensitivity index d' on force increment can be fit by a straight line through the origin and the just-noticeable difference (JND) in force can thus be described by the inverse of the slope of this line. The receiver operating characteristic (ROC) was measured by varying the a priori probabilities of the two alternatives, reference force and reference force plus an increment, in one-interval, two-alternative, forced-choice experiments. When plotted on normal deviate coordinates, the ROC's were roughly straight lines of unit slope, thus supporting the assumption of equal-variance normal distributions and the use of the conventional d' measure. The JND was roughly 6-8 percent for reference force ranging from 2.5 to 10 newtons, pushing distance from 5 to 30 mm, and initial finger-span from 45 to 125 mm. Also, the JND remained the same when the subjects were instructed to change the average speed of pushing from 23 to 153 mm/sec. The pushing was terminated by reaching either a wall or a well, and the JND's were essentially the same in both cases.

  9. Plasma igniter for internal-combustion engines

    NASA Technical Reports Server (NTRS)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  10. Dilatonic Entropic Force

    NASA Astrophysics Data System (ADS)

    Sakalli, I.

    2011-08-01

    We show in detail that the entropic force of the static spherically symmetric spacetimes with unusual asymptotics can be calculated through the Verlinde's arguments. We introduce three different holographic screen candidates, which are first employed thoroughly by Myung and Kim [Phys. Rev. D 81, 105012 (2010)] for Schwarzschild black hole solutions, in order to identify the entropic force arising between a charged dilaton black hole and a test particle. The significance of the dilaton parameter on the entropic force is highlighted, and shown graphically.

  11. International Curriculums.

    ERIC Educational Resources Information Center

    Neal, Larry L.

    This workshop presentation on international curriculums in the field of parks, recreation, leisure, cultural services, and travel/tourism comments that the literature is replete with articles addressing what the field is about, but not about curriculum issues, models, and structure. It reports an international survey of 12 college educators…

  12. Causal reasoning with forces

    PubMed Central

    Wolff, Phillip; Barbey, Aron K.

    2015-01-01

    Causal composition allows people to generate new causal relations by combining existing causal knowledge. We introduce a new computational model of such reasoning, the force theory, which holds that people compose causal relations by simulating the processes that join forces in the world, and compare this theory with the mental model theory (Khemlani et al., 2014) and the causal model theory (Sloman et al., 2009), which explain causal composition on the basis of mental models and structural equations, respectively. In one experiment, the force theory was uniquely able to account for people's ability to compose causal relationships from complex animations of real-world events. In three additional experiments, the force theory did as well as or better than the other two theories in explaining the causal compositions people generated from linguistically presented causal relations. Implications for causal learning and the hierarchical structure of causal knowledge are discussed. PMID:25653611

  13. Quantized Casimir force.

    PubMed

    Tse, Wang-Kong; MacDonald, A H

    2012-12-01

    We investigate the Casimir effect between two-dimensional electron systems driven to the quantum Hall regime by a strong perpendicular magnetic field. In the large-separation (d) limit where retardation effects are essential, we find (i) that the Casimir force is quantized in units of 3ħcα(2)/8π(2)d(4) and (ii) that the force is repulsive for mirrors with the same type of carrier and attractive for mirrors with opposite types of carrier. The sign of the Casimir force is therefore electrically tunable in ambipolar materials such as graphene. The Casimir force is suppressed when one mirror is a charge-neutral graphene system in a filling factor ν=0 quantum Hall state. PMID:23368242

  14. Forces in Motion.

    ERIC Educational Resources Information Center

    Goodsell, David; And Others

    1995-01-01

    Describes an activity to give students experience with the variables and forces impacting a moving body on an inclined plane by observing a ball as it rolls down an inclined PVC pipe of fixed length. Includes a student worksheet. (MKR)

  15. Strategic forces briefing

    SciTech Connect

    Bing, G.; Chrzanowski, P.; May, M.; Nordyke, M.

    1989-04-06

    The Strategic Forces Briefing'' is our attempt, accomplished over the past several months, to outline and highlight the more significant strategic force issues that must be addressed in the near future. Some issues are recurrent: the need for an effective modernized Triad and a constant concern for force survivability. Some issues derive from arms control: the Strategic Arms Reduction Talks (SALT) are sufficiently advanced to set broad numerical limits on forces, but not so constraining as to preclude choices among weapon systems and deployment modes. Finally, a new administration faced with serious budgetary problems must strive for the most effective strategic forces limited dollars can buy and support. A review of strategic forces logically begins with consideration of the missions the forces are charged with. We begin the briefing with a short review of targeting policy and implementation within the constraints of available unclassified information. We then review each element of the Triad with sections on SLBMs, ICBMs, and Air-Breathing (bomber and cruise missile) systems. A short section at the end deals with the potential impact of strategic defense on offensive force planning. We consider ABM, ASAT, and air defense; but we do not attempt to address the technical issues of strategic defense per se. The final section gives a brief overview of the tritium supply problem. We conclude with a summary of recommendations that emerge from our review. The results of calculation on the effectiveness of various weapon systems as a function of cost that are presented in the briefing are by Paul Chrzanowski.

  16. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  17. Force user's manual, revised

    NASA Technical Reports Server (NTRS)

    Jordan, Harry F.; Benten, Muhammad S.; Arenstorf, Norbert S.; Ramanan, Aruna V.

    1987-01-01

    A methodology for writing parallel programs for shared memory multiprocessors has been formalized as an extension to the Fortran language and implemented as a macro preprocessor. The extended language is known as the Force, and this manual describes how to write Force programs and execute them on the Flexible Computer Corporation Flex/32, the Encore Multimax and the Sequent Balance computers. The parallel extension macros are described in detail, but knowledge of Fortran is assumed.

  18. Van der Waals Forces

    NASA Astrophysics Data System (ADS)

    Parsegian, V. Adrian

    2006-03-01

    This should prove to be the definitive work explaining van der Waals forces, how to calculate them and take account of their impact under any circumstances and conditions. These weak intermolecular forces are of truly pervasive impact, and biologists, chemists, physicists and engineers will profit greatly from the thorough grounding in these fundamental forces that this book offers. Parsegian has organized his book at three successive levels of mathematical sophistication, to satisfy the needs and interests of readers at all levels of preparation. The Prelude and Level 1 are intended to give everyone an overview in words and pictures of the modern theory of van der Waals forces. Level 2 gives the formulae and a wide range of algorithms to let readers compute the van der Waals forces under virtually any physical or physiological conditions. Level 3 offers a rigorous basic formulation of the theory. Author is among the most highly respected biophysicists Van der Waals forces are significant for a wide range of questions and problems in the life sciences, chemistry, physics, and engineering, ranging up to the macro level No other book that develops the subject vigorously, and this book also makes the subject intuitively accessible to students who had not previously been mathematically sophisticated enough to calculate them

  19. Optical Bernoulli forces

    NASA Astrophysics Data System (ADS)

    Movassagh, Ramis; Johnson, Steven G.

    2013-08-01

    By Bernoulli's law, an increase in the relative speed of a fluid around a body is accompanied by a decrease in the pressure. Therefore, a rotating body in a fluid stream experiences a force perpendicular to the motion of the fluid because of the unequal relative speed of the fluid across its surface. It is well known that light has a constant speed irrespective of the relative motion. Does a rotating body immersed in a stream of photons experience a Bernoulli-like force? We show that, indeed, a rotating dielectric cylinder experiences such a lateral force from an electromagnetic wave. In fact, the sign of the lateral force is the same as that of the fluid-mechanical analog as long as the electric susceptibility is positive (ɛ>ɛ0), but for negative-susceptibility materials (e.g., metals) we show that the lateral force is in the opposite direction. Because these results are derived from a classical electromagnetic scattering problem, Mie-resonance enhancements that occur in other scattering phenomena also enhance the lateral force.

  20. Finding forced trends in oceanic oxygen

    NASA Astrophysics Data System (ADS)

    Long, Matthew C.; Deutsch, Curtis; Ito, Taka

    2016-02-01

    Anthropogenically forced trends in oceanic dissolved oxygen are evaluated in Earth system models in the context of natural variability. A large ensemble of a single Earth system model is used to clearly identify the forced component of change in interior oxygen distributions and to evaluate the magnitude of this signal relative to noise generated by internal climate variability. The time of emergence of forced trends is quantified on the basis of anomalies in oxygen concentrations and trends. We find that the forced signal should already be evident in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins; widespread detection of forced deoxygenation is possible by 2030-2040. In addition to considering spatially discrete metrics of detection, we evaluate the similarity of the spatial structures associated with natural variability and the forced trend. Outside of the subtropics, these patterns are not wholly distinct on the isopycnal surfaces considered, and therefore, this approach does not provide significantly advanced detection. Our results clearly demonstrate the strong impact of natural climate variability on interior oxygen distributions, providing an important context for interpreting observations.

  1. Forced marriage, forced sex: the perils of childhood for girls.

    PubMed

    Ouattara, M; Sen, P; Thomson, M

    1998-11-01

    A recently formed interagency Forum on the Rights of Girls and Women in Marriage is investigating the widespread problem of nonconsensual marriage and forced sex and advocating for legislative and policy initiatives. This article reviews three research projects in this area: research by Anti-Slavery International on child marriage in parts of West Africa, an investigation by Save the Children of children's views of early marriage, and research conducted by CHANGE on women's resistance to domestic violence in Calcutta, India. Girls who marry before 15 years of age are more likely to be illiterate than their older counterparts, more likely to be dowry payment brides, less likely to come into contact with development projects, have higher rates of infant mortality, and are most vulnerable to sexual violence. In many cases, intercourse is initiated before the girl begins to menstruate. Although adult women also face sexual violence within marriage, this problem is all the more traumatic for girls who lack any information about sexuality. Sex with girls below a certain age is usually covered by rape legislation, but, in countries such as India, this is mitigated by the religiously defined personal laws. The absence of adequate legal and policy action frameworks to deal with the rights of girls, coupled with the lack of sanctions against these abuses, comprise state complicity and neglect of duty under international law to this vulnerable group. PMID:12294409

  2. International Geology

    ERIC Educational Resources Information Center

    Hoover, Linn

    1977-01-01

    Briefly discusses recent international programs in various areas of geology, including land-use problems, coping with geological hazards, and conserving the environment while searching for energy and mineral resources. (MLH)

  3. International Health

    MedlinePlus

    ... create refugee populations with immediate and long-term health problems. Some of the major diseases currently affecting ... also an international problem which can affect people's health. Many countries and health organizations are working together ...

  4. Lenz's Law: Feel the Force.

    ERIC Educational Resources Information Center

    Sawicki, Charles A.

    1996-01-01

    Describes a simple, inexpensive system that allows students to have hands-on contact with simple experiments involving forces generated by induced currents. Discusses the use of a dynamic force sensor in making quantitative measurements of the forces generated. (JRH)

  5. Surgical force detection probe

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Roberts, Paul; Scott, Charles; Prass, Richard

    1991-01-01

    The development progress of a precision electro-mechanical instrument which allows the detection and documentation of the forces and moment applied to human tissue during surgery (under actual operation room conditions), is reported. The pen-shaped prototype probe which measures 1/2 inch in diameter and 7 inches in length was fabricated using an aerodynamic balance. The aerodynamic balance, a standard wind tunnel force and moment sensing transducer, measures the forces and the moments transmitted through the surgeon's hand to the human tissue during surgery. The prototype probe which was fabricated as a development tool was tested successfully. The final version of the surgical force detection probe will be designed based on additional laboratory tests in order to establish the full scale loads. It is expected that the final product will require a simplified aerodynamic balance with two or three force components and one moment component with lighter full scale loads. A signal conditioner was fabricated to process and display the outputs from the prototype probe. This unit will be interfaced with a PC-based data system to provide automatic data acquisition, data processing, and graphics display. The expected overall accuracy of the probe is better than one percent full scale.

  6. Radiative Forcing by Contrails

    NASA Technical Reports Server (NTRS)

    Meerkoetter, R.; Schumann, U.; Doelling, D. R.; Nakajima, T.; Tsushima, Y.

    1999-01-01

    A parametric study of the instantaneous radiative impact of contrails is presented using three different radiative transfer models for a series of model atmospheres and cloud parameters. Contrails are treated as geometrically and optically thin plane parallel homogeneous cirrus layers in a static atmospheres The ice water content is varied as a function of ambient temperature. The model atmospheres include tropical, mid-latitude, and subarctic summer and winter atmospheres Optically thin contrails cause a positive net forcing at top of the atmosphere. At the surface the radiative forcing is negative during daytime. The forcing increases with the optical depth and the amount of contrail cover. At the top of the atmosphere a mean contrail cover of 0.1% with average optical depth of 0.2 to 0.5 causes about 0.01 to 0.03 W/m(exp 2)a daily mean instantaneous radiative forcing. Contrails cool the surface during the day and heat the surface during the night, and hence reduce the daily temperature amplitude The net effect depends strongly on the daily variation of contrail cloud cover. The indirect radiative forcing due to particle changes in natural cirrus clouds may be of the same magnitude as the direct one due to additional cover.

  7. Forces and torques on the nanoscale: from measurement to applications

    NASA Astrophysics Data System (ADS)

    Volpe, Giovanni

    2012-10-01

    The possibility of measuring microscopic forces down to the femtonewton range has opened new possibilities in fields such as biophysics and nanophotonics. I will review some of the techniques most often employed, namely the photonic force microscope (PFM) and the total internal reflection microscope (TIRM), which are able to measure tiny forces acting on optically trapped particles. I will then discuss several applications of such nanoscopic forces: from plasmonic optical manipulation, to self-propelled microswimmers, to self-organization in large ensembles of particles.

  8. Trends of measured climate forcing agents

    PubMed Central

    Hansen, James E.; Sato, Makiko

    2001-01-01

    The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/m2 per century. This growth rate has since declined to ≈3 W/m2 per century, largely because of cooperative international actions. We argue that trends can be reduced to the level needed for the moderate “alternative” climate scenario (≈2 W/m2 per century for the next 50 years) by means of concerted actions that have other benefits, but the forcing reductions are not automatic “co-benefits” of actions that slow CO2 emissions. Current trends of climate forcings by aerosols remain very uncertain. Nevertheless, practical constraints on changes in emission levels suggest that global warming at a rate +0.15 ± 0.05°C per decade will occur over the next several decades. PMID:11752424

  9. Trends of Measured Climate Forcing Agents

    NASA Technical Reports Server (NTRS)

    Hansen, James E.; Sato, Makiko; Einaudi, Franco (Technical Monitor)

    2002-01-01

    The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/sq m per century. This growth rate has since declined to approximately equal to 3 W/sq m per century, largely because of cooperative international actions. We argue that trends can be reduced to the level needed for the moderate "alternative" climate scenario (approximately equal to 2 W/M2 per century for the next 50 years) by means of concerted actions that have other benefits, but the forcing reductions are not automatic "co-benefits" of actions that slow CO2 emissions. Current trends of climate forcings by aerosols remain very uncertain. Nevertheless, practical constraints on changes in emission levels suggest that global warming at a rate + 0.15 +/- 0.05 C per decade will occur over the next several decades.

  10. Assessing the industry using Porter's five forces.

    PubMed

    2014-01-01

    To develop a business and plan for the future, there is a need to assess the current situation. One way of doing this is to use Porter's five forces framework. This was the brainchild of Harvard Business School's Michael Porter and developed in 1979. Looking at the competitive intensity of an industry, the model assesses internal and external factors that act together to determine the direction of the business; taken together, this gives an indication of the attractiveness of the industry. PMID:24470612

  11. FLOW VISUALIZATION OF FORCED AND NATURAL CONVECTION IN INTERNAL CAVITIES

    EPA Science Inventory

    This research project will focus efforts on developing techniques to model fluid flow in spent nuclear fuel canisters. One treatment technique is to inject gases which react with spent fuels into storage canisters, preventing the occurrence of pyrophoric reactions. The primary go...

  12. Flow Visualization of Forced and Natural Convection in Internal Cavities

    SciTech Connect

    John Crepeau; Hugh M. Mcllroy,Jr.; Donald M. McEligot; Keith G. Condie; Glenn McCreery; Randy Clarsean; Robert S. Brodkey; Yann G. Guezennec

    2002-01-31

    The report descries innovative flow visualization techniques, fluid mechanics measurements and computational models of flows in a spent nuclear fuel canister. The flow visualization methods used a fluid that reacted with a metal plate to show how a local reaction affects the surrounding flow. A matched index of refraction facility was used to take mean flow and turbulence measurements within a generic spent nuclear fuel canister. Computational models were also made of the flow in the canister. It was determined that the flow field in the canister was very complex, and modifications may need to be made to ensure that the spent fuel elements are completely passivated.

  13. Does ENSO Force the PNA?.

    NASA Astrophysics Data System (ADS)

    Straus, David M.; Shukla, J.

    2002-09-01

    The primary effect of El Niño-Southern Oscillation (ENSO) sea surface temperature (SST) anomalies is to force distinct midlatitude patterns, and not only to modify the probability of the internal variability patterns [such as the Pacific-North American (PNA) pattern of Wallace and Gutzler]. Both the spatial structure and probability distribution of the external ENSO pattern are distinct from the PNA pattern. Ensemble general circulation model (GCM) integrations for 30 winters have been analyzed in the Pacific-North America region. These winters span the recent period of 1981/82 through 1998/99, plus 12 earlier winters; the entire dataset includes six El Niño (warm) and seven La Niña (cold) events. The ensemble size is nine simulations. Empirical orthogonal function (EOF) analysis is carried out for all GCMs and observed seasonal means, for the GCM ensemble means, and for the GCM deviations about the ensemble means. EOF-1 of the GCM 200-hPa height (Z) ensemble mean agrees well with EOF-1 of all GCM seasonal means, and with the pattern that optimally filters out the internal variability. This ENSO pattern agrees with EOF-1 of reanalysis data, although the latter is modified in the Atlantic sector by the presence of the North Atlantic Oscillation pattern. An internal pattern closely resembling the PNA pattern is obtained here from reanalyses as EOF-2 of Z for 37 normal winters (winters that are neither warm nor cold). The GCM version of the PNA pattern can be seen in EOF-2 of the deviation of the GCM means about the ensemble mean, EOF-3 of all GCM seasonal means, and EOF-2 of a GCM integration made with climatologically varying SST.Projections of all GCM seasonal means in a low-dimensional space indicate a segregation of the warm winter seasonal means from those of normal winters along the axis representing the external pattern. There is no support for the hypothesis that the probability distribution functions (pdfs) of internal and external variability are similar

  14. Linear force device

    NASA Technical Reports Server (NTRS)

    Clancy, John P.

    1988-01-01

    The object of the invention is to provide a mechanical force actuator which is lightweight and manipulatable and utilizes linear motion for push or pull forces while maintaining a constant overall length. The mechanical force producing mechanism comprises a linear actuator mechanism and a linear motion shaft mounted parallel to one another. The linear motion shaft is connected to a stationary or fixed housing and to a movable housing where the movable housing is mechanically actuated through actuator mechanism by either manual means or motor means. The housings are adapted to releasably receive a variety of jaw or pulling elements adapted for clamping or prying action. The stationary housing is adapted to be pivotally mounted to permit an angular position of the housing to allow the tool to adapt to skewed interfaces. The actuator mechanisms is operated by a gear train to obtain linear motion of the actuator mechanism.

  15. Carbohydrate force fields

    PubMed Central

    Foley, B. Lachele; Tessier, Matthew B.; Woods, Robert J.

    2014-01-01

    Carbohydrates present a special set of challenges to the generation of force fields. First, the tertiary structures of monosaccharides are complex merely by virtue of their exceptionally high number of chiral centers. In addition, their electronic characteristics lead to molecular geometries and electrostatic landscapes that can be challenging to predict and model. The monosaccharide units can also interconnect in many ways, resulting in a large number of possible oligosaccharides and polysaccharides, both linear and branched. These larger structures contain a number of rotatable bonds, meaning they potentially sample an enormous conformational space. This article briefly reviews the history of carbohydrate force fields, examining and comparing their challenges, forms, philosophies, and development strategies. Then it presents a survey of recent uses of these force fields, noting trends, strengths, deficiencies, and possible directions for future expansion. PMID:25530813

  16. ILO - International Migration Programme.

    PubMed

    Boudraa, Miriam

    2011-01-01

    In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration". PMID:22073693

  17. International Education--What's in a Name?

    ERIC Educational Resources Information Center

    Parker, Walter C.

    2008-01-01

    Public and private schools in the U.S. increasingly are adopting international education. The author asks, "What is it?" and finds a jumble of meanings and programs. Contradictory forces, such as nationalism and cosmopolitanism, are at play. Thus international education can have very different meanings at different schools.

  18. [Forced spirometry procedure].

    PubMed

    Cortés Aguilera, Antonio Javier

    2008-11-01

    Forced spirometry consists in a complementary test which is carried out in a health office in a workplace in order to determine the lung capacity of workers exposed to determined professional risks or those susceptible to determined working conditions which could lead to the development of respiratory problems. This test has been developed based on health vigilance laws under Article 22 of the Law for Prevention of Risks in the Workplace and requires that the technician, a nurse in a workplace, who performs it have some knowledge and skills regarding its use, following the norms for forced spirometry set by the Spanish Association for Pneumatology and Thoracic Surgery (SEPAR). PMID:19203116

  19. Radiative Forcing of Climate Change

    SciTech Connect

    Ramaswamy, V.; Boucher, Olivier; Haigh, J.; Hauglustaine, D.; Haywood, J.; Myhre, G.; Nakajima, Takahito; Shi, Guangyu; Solomon, S.; Betts, Robert E.; Charlson, R.; Chuang, C. C.; Daniel, J. S.; Del Genio, Anthony D.; Feichter, J.; Fuglestvedt, J.; Forster, P. M.; Ghan, Steven J.; Jones, A.; Kiehl, J. T.; Koch, D.; Land, C.; Lean, J.; Lohmann, Ulrike; Minschwaner, K.; Penner, Joyce E.; Roberts, D. L.; Rodhe, H.; Roelofs, G.-J.; Rotstayn, Leon D.; Schneider, T. L.; Schumann, U.; Schwartz, Stephen E.; Schwartzkopf, M. D.; Shine, K. P.; Smith, Steven J.; Stevenson, D. S.; Stordal, F.; Tegen, I.; van Dorland, R.; Zhang, Y.; Srinivasan, J.; Joos, Fortunat

    2001-10-01

    Chapter 6 of the IPCC Third Assessment Report Climate Change 2001: The Scientific Basis. Sections include: Executive Summary 6.1 Radiative Forcing 6.2 Forcing-Response Relationship 6.3 Well-Mixed Greenhouse Gases 6.4 Stratospheric Ozone 6.5 Radiative Forcing By Tropospheric Ozone 6.6 Indirect Forcings due to Chemistry 6.7 The Direct Radiative Forcing of Tropospheric Aerosols 6.8 The Indirect Radiative Forcing of Tropospheric Aerosols 6.9 Stratospheric Aerosols 6.10 Land-use Change (Surface Albedo Effect) 6.11 Solar Forcing of Climate 6.12 Global Warming Potentials hydrocarbons 6.13 Global Mean Radiative Forcings 6.14 The Geographical Distribution of the Radiative Forcings 6.15 Time Evolution of Radiative Forcings Appendix 6.1 Elements of Radiative Forcing Concept References.

  20. A New Method of Comparing Forcing Agents in Climate Models

    SciTech Connect

    Kravitz, Benjamin S.; MacMartin, Douglas; Rasch, Philip J.; Jarvis, Andrew

    2015-10-14

    We describe a new method of comparing different climate forcing agents (e.g., CO2, CH4, and solar irradiance) that avoids many of the ambiguities introduced by temperature-related climate feedbacks. This is achieved by introducing an explicit feedback loop external to the climate model that adjusts one forcing agent to balance another while keeping global mean surface temperature constant. Compared to current approaches, this method has two main advantages: (i) the need to define radiative forcing is bypassed and (ii) by maintaining roughly constant global mean temperature, the effects of state dependence on internal feedback strengths are minimized. We demonstrate this approach for several different forcing agents and derive the relationships between these forcing agents in two climate models; comparisons between forcing agents are highly linear in concordance with predicted functional forms. Transitivity of the relationships between the forcing agents appears to hold within a wide range of forcing. The relationships between the forcing agents obtained from this method are consistent across both models but differ from relationships that would be obtained from calculations of radiative forcing, highlighting the importance of controlling for surface temperature feedback effects when separating radiative forcing and climate response.

  1. The Force of Ideas

    ERIC Educational Resources Information Center

    Ascher, Carol

    2005-01-01

    "The Force of Ideas" describes a little-known aspect of both educational history and Viennese psychoanalysis during the interwar years: the movement for psychoanalytic pedagogy. The author traces her father's own story, beginning with his application to the Vienna Psychoanalytic Society for training as a psychoanalytic pedagogue, as a way to…

  2. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus; Taylor, Foreword by John C.

    2005-10-01

    Foreword John C. Taylor; 1. Unification of fundamental forces Abdus Salam; 2. History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac Abdus Salam; 3. Theory, criticism, and a philosophy Werner Heisenberg; 4. Methods in theoretical physics Paul Adrian Maurice Dirac.

  3. Reduction in Force.

    ERIC Educational Resources Information Center

    Wood, R. Craig

    This chapter of "Principles of School Business Management" reviews several concerns that must be addressed by school business administrators in districts facing declining enrollments and the need for reductions in force. The chapter first looks at the business administrator's significant role in planning for retrenchment. The chapter then…

  4. Reduction in Force.

    ERIC Educational Resources Information Center

    Phay, Robert

    Chapter 2 in a book on school law discusses the reasons for reduction in force (RIF) and presents a set of model regulations for school districts as the best means of minimizing legal problems resulting from RIF. The reasons for RIF include declining student enrollments; reduced turnover among teachers; changes in programs; and more constrained…

  5. Wearing Forces Spectacles

    ERIC Educational Resources Information Center

    Perrin, Graham

    2012-01-01

    When providing training to teachers struggling with the concept of forces, the author encourages them to start with something within the experience of the children they are teaching. For example, show them photographs taken on windy days, such as that of a tree, and ask them to explain what is happening. This encourages the children to focus on…

  6. Forces in nonlinear media

    NASA Astrophysics Data System (ADS)

    Milgrom, Mordehai

    2002-02-01

    I investigate the properties of forces on bodies in theories governed by the generalized Poisson equation μ(|ϕ| /a0)ϕ] ∝ Gρ, for the potential ϕ produced by a distribution of sources ρ. This equation describes, inter alia, media with a response coefficient, μ, that depends on the field strength, such as in nonlinear, dielectric or diamagnetic, media; nonlinear transport problems with field-strength-dependent conductivity or diffusion coefficient; nonlinear electrostatics, as in the Born-Infeld theory; certain stationary potential flows in compressible fluids, in which case the forces act on sources or obstacles in the flow. The expressions for the force on a point charge are derived exactly for the limits of very low and very high charge. The force on an arbitrary body in an external field of asymptotically constant gradient, -g0, is shown to be F = Qg0, where Q is the total effective charge of the body. The corollary Q = 0 → F = 0 is a generalization of d'Alembert's paradox. I show that for G > 0 (as in Newtonian gravity) two point charges of the same (opposite) sign still attract (repel). The opposite is true for G < 0. I discuss its generalization to extended bodies and derive virial relations.

  7. Force limited vibration testing

    NASA Technical Reports Server (NTRS)

    Scharton, Terry D.

    1991-01-01

    A new method of conducting lab vibration tests of spacecraft equipment was developed to more closely simulate the vibration environment experienced when the spacecraft is launched on a rocket. The improved tests are tailored to identify equipment design and workmanship problems without inducing artificial failures that would not have occurred at launch. These new, less destructive types of vibration tests are essential to JPL's protoflight test approach in which lab testing is conducted using the flight equipment, often one of a kind, to save time and money. In conventional vibration tests, only the input vibratory motion is specified; the feedback, or reaction force, between the test item and the vibration machine is ignored. Most test failures occur when the test item goes into resonance, and the reaction force becomes very large. It has long been recognized that the large reaction force is a test artifact which does not occur with the lightweight, flexible mounting structures characteristic of spacecraft and space vehicles. In new vibration tests, both the motion and the force provided to the test item by the vibration machine are controlled, so that the vibration ride experienced by the test item is as in flight.

  8. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  9. The Dynamic Force Table

    ERIC Educational Resources Information Center

    Geddes, John B.; Black, Kelly

    2008-01-01

    We examine an experimental apparatus that is used to motivate the connections between the basic properties of vectors, potential functions, systems of nonlinear equations, and Newton's method for nonlinear systems of equations. The apparatus is an adaptation of a force table where we remove the center-pin and allow the center-ring to move freely.…

  10. Mining Task Force Report.

    ERIC Educational Resources Information Center

    Saskatchewan Inst. of Applied Science and Technology, Saskatoon.

    In fall 1988, the Board of Directors of the Saskatchewan Institute of Applied Science and Technology (SIAST) created a task force to study the training needs of the mining industry in the province and evaluate SIAST's responsiveness to those needs. After assessing the technological changes taking place in the industry, surveying manpower needs,…

  11. Lorentz force particle analyzer

    NASA Astrophysics Data System (ADS)

    Wang, Xiaodong; Thess, André; Moreau, René; Tan, Yanqing; Dai, Shangjun; Tao, Zhen; Yang, Wenzhi; Wang, Bo

    2016-07-01

    A new contactless technique is presented for the detection of micron-sized insulating particles in the flow of an electrically conducting fluid. A transverse magnetic field brakes this flow and tends to become entrained in the flow direction by a Lorentz force, whose reaction force on the magnetic-field-generating system can be measured. The presence of insulating particles suspended in the fluid produce changes in this Lorentz force, generating pulses in it; these pulses enable the particles to be counted and sized. A two-dimensional numerical model that employs a moving mesh method demonstrates the measurement principle when such a particle is present. Two prototypes and a three-dimensional numerical model are used to demonstrate the feasibility of a Lorentz force particle analyzer (LFPA). The findings of this study conclude that such an LFPA, which offers contactless and on-line quantitative measurements, can be applied to an extensive range of applications. These applications include measurements of the cleanliness of high-temperature and aggressive molten metal, such as aluminum and steel alloys, and the clean manufacturing of semiconductors.

  12. Internal shim

    DOEpatents

    Barth, Clyde H.; Blizinski, Theodore W.

    2003-05-13

    An internal shim used to accurately measure spaces in conjunction with a standard small probe has a shim top and a chassis. The internal shim is adjustably fixed within the space to be measured using grippers that emerge from the chassis and which are controlled by an arm pivotably attached to the shim top. A standard small probe passes through the shim along guides on the chassis and measures the distance between the exterior of the chassis and the boundary. By summing the measurements on each side of the chassis and the width of the chassis, the dimension of the space can be determined to within 0.001 inches.

  13. Chiral drag force

    NASA Astrophysics Data System (ADS)

    Rajagopal, Krishna; Sadofyev, Andrey V.

    2015-10-01

    We provide a holographic evaluation of novel contributions to the drag force acting on a heavy quark moving through strongly interacting plasma. The new contributions are chiral in the sense that they act in opposite directions in plasmas containing an excess of left- or right-handed quarks. The new contributions are proportional to the coefficient of the axial anomaly, and in this sense also are chiral. These new contributions to the drag force act either parallel to or antiparallel to an external magnetic field or to the vorticity of the fluid plasma. In all these respects, these contributions to the drag force felt by a heavy quark are analogous to the chiral magnetic effect (CME) on light quarks. However, the new contribution to the drag force is independent of the electric charge of the heavy quark and is the same for heavy quarks and antiquarks, meaning that these novel effects do not in fact contribute to the CME current. We show that although the chiral drag force can be non-vanishing for heavy quarks that are at rest in the local fluid rest frame, it does vanish for heavy quarks that are at rest in a suitably chosen frame. In this frame, the heavy quark at rest sees counterpropagating momentum and charge currents, both proportional to the axial anomaly coefficient, but feels no drag force. This provides strong concrete evidence for the absence of dissipation in chiral transport, something that has been predicted previously via consideration of symmetries. Along the way to our principal results, we provide a general calculation of the corrections to the drag force due to the presence of gradients in the flowing fluid in the presence of a nonzero chemical potential. We close with a consequence of our result that is at least in principle observable in heavy ion collisions, namely an anticorrelation between the direction of the CME current for light quarks in a given event and the direction of the kick given to the momentum of all the heavy quarks and

  14. 26 CFR 1.113-1 - Mustering-out payments for members of the Armed Forces.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Forces. 1.113-1 Section 1.113-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....113-1 Mustering-out payments for members of the Armed Forces. For the purposes of the exclusion from gross income under section 113 of mustering-out payments with respect to service in the Armed...

  15. 26 CFR 1.113-1 - Mustering-out payments for members of the Armed Forces.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Forces. 1.113-1 Section 1.113-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....113-1 Mustering-out payments for members of the Armed Forces. For the purposes of the exclusion from gross income under section 113 of mustering-out payments with respect to service in the Armed...

  16. 26 CFR 1.113-1 - Mustering-out payments for members of the Armed Forces.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Forces. 1.113-1 Section 1.113-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....113-1 Mustering-out payments for members of the Armed Forces. For the purposes of the exclusion from gross income under section 113 of mustering-out payments with respect to service in the Armed...

  17. 26 CFR 1.113-1 - Mustering-out payments for members of the Armed Forces.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Forces. 1.113-1 Section 1.113-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....113-1 Mustering-out payments for members of the Armed Forces. For the purposes of the exclusion from gross income under section 113 of mustering-out payments with respect to service in the Armed...

  18. 26 CFR 1.113-1 - Mustering-out payments for members of the Armed Forces.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Forces. 1.113-1 Section 1.113-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....113-1 Mustering-out payments for members of the Armed Forces. For the purposes of the exclusion from gross income under section 113 of mustering-out payments with respect to service in the Armed...

  19. Universal spin-momentum locked optical forces

    NASA Astrophysics Data System (ADS)

    Kalhor, Farid; Thundat, Thomas; Jacob, Zubin

    2016-02-01

    Evanescent electromagnetic waves possess spin-momentum locking, where the direction of propagation (momentum) is locked to the inherent polarization of the wave (transverse spin). We study the optical forces arising from this universal phenomenon and show that the fundamental origin of recently reported non-trivial optical chiral forces is spin-momentum locking. For evanescent waves, we show that the direction of energy flow, the direction of decay, and the direction of spin follow a right hand rule for three different cases of total internal reflection, surface plasmon polaritons, and HE11 mode of an optical fiber. Furthermore, we explain how the recently reported phenomena of lateral optical force on chiral and achiral particles are caused by the transverse spin of the evanescent field and the spin-momentum locking phenomenon. Finally, we propose an experiment to identify the unique lateral forces arising from the transverse spin in the optical fiber and point to fundamental differences of the spin density from the well-known orbital angular momentum of light. Our work presents a unified view on spin-momentum locking and how it affects optical forces on chiral and achiral particles.

  20. Motion and force control for multiple cooperative manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz, Kenneth

    1989-01-01

    The motion and force control of multiple robot arms manipulating a commonly held object is addressed. A general control paradigm that decouples the motion and force control problems is introduced. For motion control, there are three natural choices: (1) joint torques, (2) arm-tip force vectors, and (3) the acceleration of a generalized coordinate. Choice (1) allows a class of relatively model-independent control laws by exploiting the Hamiltonian structure of the open-loop system; (2) and (3) require the full model information but produce simpler problems. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, the allocation of the desired end-effector control force to the joint actuators can be optimized; otherwise the internal force can be controlled about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  1. 26 CFR 49.4263-4 - Members of the armed forces.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Members of the armed forces. 49.4263-4 Section... the armed forces. The tax imposed by section 4261 does not apply to amounts paid for transportation or..., Air Force, Navy, Marine Corps, and Coast Guard, including authorized cadets and midshipmen,...

  2. 5 CFR 362.205 - Reduction in force (RIF) and termination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Reduction in force (RIF) and termination... REGULATIONS PATHWAYS PROGRAMS Internship Program § 362.205 Reduction in force (RIF) and termination. (a) Reduction in force. Interns are covered by part 351 of this chapter for purposes of RIF. (1) Tenure...

  3. 26 CFR 20.2201-1 - Members of the Armed Forces dying during an induction period.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 14 2013-04-01 2013-04-01 false Members of the Armed Forces dying during an... Miscellaneous § 20.2201-1 Members of the Armed Forces dying during an induction period. (a) The additional...) (see paragraph (b) of this section) and while in active service as a member of the Armed Forces of...

  4. 26 CFR 20.2201-1 - Members of the Armed Forces dying during an induction period.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true Members of the Armed Forces dying during an... Miscellaneous § 20.2201-1 Members of the Armed Forces dying during an induction period. (a) The additional...) (see paragraph (b) of this section) and while in active service as a member of the Armed Forces of...

  5. 75 FR 11893 - Food and Drug Administration Transparency Task Force; Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... HUMAN SERVICES Food and Drug Administration Food and Drug Administration Transparency Task Force... transparent, collaborative, and participatory government. FDA has formed an internal Transparency Task Force..., the Task Force has held two public meetings, on June 24, 2009, and November 3, 2009, and established...

  6. 26 CFR 49.4263-4 - Members of the armed forces.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Members of the armed forces. 49.4263-4 Section... the armed forces. The tax imposed by section 4261 does not apply to amounts paid for transportation or..., Air Force, Navy, Marine Corps, and Coast Guard, including authorized cadets and midshipmen,...

  7. 26 CFR 20.2201-1 - Members of the Armed Forces dying during an induction period.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Members of the Armed Forces dying during an... Miscellaneous § 20.2201-1 Members of the Armed Forces dying during an induction period. (a) The additional...) (see paragraph (b) of this section) and while in active service as a member of the Armed Forces of...

  8. 26 CFR 49.4263-4 - Members of the armed forces.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Members of the armed forces. 49.4263-4 Section... the armed forces. The tax imposed by section 4261 does not apply to amounts paid for transportation or..., Air Force, Navy, Marine Corps, and Coast Guard, including authorized cadets and midshipmen,...

  9. 5 CFR 362.205 - Reduction in force (RIF) and termination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Reduction in force (RIF) and termination... REGULATIONS PATHWAYS PROGRAMS Internship Program § 362.205 Reduction in force (RIF) and termination. (a) Reduction in force. Interns are covered by part 351 of this chapter for purposes of RIF. (1) Tenure...

  10. 26 CFR 49.4263-4 - Members of the armed forces.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Members of the armed forces. 49.4263-4 Section... the armed forces. The tax imposed by section 4261 does not apply to amounts paid for transportation or..., Air Force, Navy, Marine Corps, and Coast Guard, including authorized cadets and midshipmen,...

  11. 26 CFR 20.2201-1 - Members of the Armed Forces dying during an induction period.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true Members of the Armed Forces dying during an... Miscellaneous § 20.2201-1 Members of the Armed Forces dying during an induction period. (a) The additional...) (see paragraph (b) of this section) and while in active service as a member of the Armed Forces of...

  12. International Entomology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pests and diseases of plants in agriculture are a shared international problem. Yet some of the very places that pest invaders come from often lack the institutional structure and organization necessary to help in understanding the biology of the pest or disease. Strengthening entomology by stimulat...

  13. International Education.

    ERIC Educational Resources Information Center

    Nicholson, R. Stephen

    In a world characterized by increasing global interdependence, the provision of international education programs must be an essential concern of the community college president. Frequently, these programs are considered too sophisticated for community college students or are misconceived as: (1) pleasure junkets; (2) strategies for increasing…

  14. International Standards.

    ERIC Educational Resources Information Center

    Havard-Williams, Peter

    1982-01-01

    Discussion of standardization on an international scale for resource sharing--cooperation, coordination, interlibrary loans, cooperative acquisition and cataloging--focuses on a definition of standards; the development of standards for cataloging; public, school, and university libraries; and library education. A 60-item bibliography is included.…

  15. International Reports.

    ERIC Educational Resources Information Center

    Tabb, Winston; Bender, David R.; Haycock, Ken; Horodyski, John

    2001-01-01

    Includes three annual reports: one from the International Federation of Library Associations and Institutions, the Special Libraries Association, and a report on innovations in Canadian libraries that discusses electronic initiatives, partnerships, books and publishing, school libraries, national issues, local challenges, and funding. (LRW)

  16. International Marketplace.

    ERIC Educational Resources Information Center

    Wells, Donald A.; And Others

    1985-01-01

    This issue begins with a conceptual introduction to economic specialization, exports and imports, and the importance of international trade. Four instructional units follow this introduction, beginning with a preschool and kindergarten unit called "Traders and Travelers," which involves young students in five activities that illustrate our…

  17. 76 FR 45311 - International Joint Commission Public Hearings on Binational Management of Lake of the Woods and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... water quality, water quantity, and related issues in the international Lake of the Woods and Rainy River... International Joint Commission Public Hearings on Binational Management of Lake of the Woods and Rainy River... International Lake of the Woods and Rainy River Watershed Task Force (Task Force). The Task Force report to...

  18. International occupational health.

    PubMed

    LaDou, Joseph

    2003-08-01

    Working conditions for the majority of the world's workers do not meet the minimum standards and guidelines set by international agencies. Occupational health and safety laws cover only about 10 percent of the population in developing countries, omitting many major hazardous industries and occupations. With rare exception, most countries defer to the United Nations the responsibility for international occupational health. The UN's international agencies have had limited success in bringing occupational health to the industrializing countries. The International Labor Organization (ILO) conventions are intended to guide all countries in the promotion of workplace safety and in managing occupational health and safety programs. ILO conventions and recommendations on occupational safety and health are international agreements that have legal force only if they are ratified by ILO member states. The most important ILO Convention on Occupational Safety and Health has been ratified by only 37 of the 175 ILO member states. Only 23 countries have ratified the ILO Employment Injury Benefits Convention that lists occupational diseases for which compensation should be paid. The World Health Organization (WHO) is responsible for the technical aspects of occupational health and safety, the promotion of medical services and hygienic standards. Limited WHO and ILO funding severely impedes the development of international occupational health. The U.S. reliance on international agencies to promote health and safety in the industrializing countries is not nearly adequate. This is particularly true if occupational health continues to be regarded primarily as an academic exercise by the developed countries, and a budgetary triviality by the international agencies. Occupational health is not a goal achievable in isolation. It should be part of a major institutional development that touches and reforms every level of government in an industrializing country. Occupational health and safety

  19. Investigation of Calibrating Force Transducer Using Sinusoidal Force

    SciTech Connect

    Zhang Li; Wang Yu; Zhang Lizhe

    2010-05-28

    Sinusoidal force calibration method was studied several years before at Physikalisch-Technische Bundesanstalt (PTB). A similar dynamic force calibration system is developed at Changcheng Institute of Metrology and Measurement (CIMM). It uses electro-dynamic shakers to generate dynamic force in the range from 1 N to 20 kN, and heterodyne laser interferometers are used for acceleration measurement. The force transducer to be calibrated is mounted on the shaker, and a mass block is screwed on the top of force transducer, the sinusoidal forces realized by accelerated load masses are traceable to acceleration and mass according to the force definition. The methods of determining Spatial-dependent acceleration on mass block and measuring the end mass of force transducer in dynamic force calibration are discussed in this paper.

  20. Force control in chronic stroke.

    PubMed

    Kang, Nyeonju; Cauraugh, James H

    2015-05-01

    Force control deficits are common dysfunctions after a stroke. This review concentrates on various force control variables associated with motor impairments and suggests new approaches to quantifying force control production and modulation. Moreover, related neurophysiological mechanisms were addressed to determine variables that affect force control capabilities. Typically, post stroke force control impairments include: (a) decreased force magnitude and asymmetrical forces between hands, (b) higher task error, (c) greater force variability, (d) increased force regularity, and (e) greater time-lag between muscular forces. Recent advances in force control analyses post stroke indicated less bimanual motor synergies and impaired low-force frequency structure. Brain imaging studies demonstrate possible neurophysiological mechanisms underlying force control impairments: (a) decreased activation in motor areas of the ipsilesional hemisphere, (b) increased activation in secondary motor areas between hemispheres, (c) cerebellum involvement, and (d) relatively greater interhemispheric inhibition from the contralesional hemisphere. Consistent with identifying neurophysiological mechanisms, analyzing bimanual motor synergies as well as low-force frequency structure will advance our understanding of post stroke force control. PMID:25704075

  1. Force Feedback Joystick

    NASA Technical Reports Server (NTRS)

    1997-01-01

    I-FORCE, a computer peripheral from Immersion Corporation, was derived from virtual environment and human factors research at the Advanced Displays and Spatial Perception Laboratory at Ames Research Center in collaboration with Stanford University Center for Design Research. Entrepreneur Louis Rosenberg, a former Stanford researcher, now president of Immersion, collaborated with Dr. Bernard Adelstein at Ames on studies of perception in virtual reality. The result was an inexpensive way to incorporate motors and a sophisticated microprocessor into joysticks and other game controllers. These devices can emulate the feel of a car on the skid, a crashing plane, the bounce of a ball, compressed springs, or other physical phenomenon. The first products incorporating I-FORCE technology include CH- Products' line of FlightStick and CombatStick controllers.

  2. Force Modulator System

    SciTech Connect

    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

  3. Suicide and Forced Marriage

    PubMed Central

    Pridmore, Saxby; Walter, Garry

    2013-01-01

    Background: The prevailing view that the vast majority of those who complete suicide have an underlying psychiatric disorder has been recently challenged by research on the contribution of “predicaments”, in the absence of mental illness, to suicide. In this paper, we sought data to support the notion that forced marriage may lead to suicide without the presence of psychiatric disorder. Methods: Historical records, newspapers, and the electronic media were searched for examples. Results: Two examples from ancient times and six from the last hundred years were located and described. Conclusion: These cases suggest that forced marriage may lead to suicide and complements earlier findings that loss of fortune, health, liberty, and reputation may lead to suicide in the absence of mental disorder. PMID:23983577

  4. Forces Driving Chaperone Action.

    PubMed

    Koldewey, Philipp; Stull, Frederick; Horowitz, Scott; Martin, Raoul; Bardwell, James C A

    2016-07-14

    It is still unclear what molecular forces drive chaperone-mediated protein folding. Here, we obtain a detailed mechanistic understanding of the forces that dictate the four key steps of chaperone-client interaction: initial binding, complex stabilization, folding, and release. Contrary to the common belief that chaperones recognize unfolding intermediates by their hydrophobic nature, we discover that the model chaperone Spy uses long-range electrostatic interactions to rapidly bind to its unfolded client protein Im7. Short-range hydrophobic interactions follow, which serve to stabilize the complex. Hydrophobic collapse of the client protein then drives its folding. By burying hydrophobic residues in its core, the client's affinity to Spy decreases, which causes client release. By allowing the client to fold itself, Spy circumvents the need for client-specific folding instructions. This mechanism might help explain how chaperones can facilitate the folding of various unrelated proteins. PMID:27293188

  5. Miniature drag force anemometer

    NASA Technical Reports Server (NTRS)

    Krause, L. N.; Fralick, G. C.

    1977-01-01

    A miniature drag force anemometer is described which is capable of measuring dynamic velocity head and flow direction. The anemometer consists of a silicon cantilevered beam 2.5 mm long, 1.5 mm wide, and 0.25 mm thick with an integrated diffused strain gage bridge, located at the base of the beam, as the force measuring element. The dynamics of the beam are like that of a second order system with a natural frequency of about 42 kHz and a damping coefficient of 0.007. The anemometer can be used in both forward and reversed flow. Measured flow characteristics up to Mach 0.6 are presented along with application examples including turbulence measurements.

  6. Stochastically forced zonal flows

    NASA Astrophysics Data System (ADS)

    Srinivasan, Kaushik

    This thesis investigates the dynamics of multiple zonal jets, that spontaneously emerge on the barotropic beta-plane, driven by a homogenous and rapidly decorrelating forcing and damped by bottom drag. Decomposing the barotropic vorticity equation into the zonal-mean and eddy equations, and neglecting the eddy-eddy interactions, defines the quasi-linear (QL) system. Numerical solution of the QL system shows zonal jets with length scales comparable to jets obtained by solving the nonlinear (NL) system. Starting with the QL system, one can construct a deterministic equation for the evolution of the two-point single-time correlation function of the vorticity, from which one can obtain the Reynolds stress that drives the zonal mean flow. This deterministic system has an exact nonlinear solution, which is a homogenous eddy field with no jets. When the forcing is also isotropic in space, we characterize the linear stability of this jetless solution by calculating the critical stability curve in the parameter space and successfully comparing this analytic result with numerical solutions of the QL system. But the critical drag required for the onset of NL zonostrophic instability is up to a factor of six smaller than that for QL zonostrophic instability. The constraint of isotropic forcing is then relaxed and spatially anisotropic forcing is used to drive the jets. Meridionally drifting jets are observed whenever the forcing breaks an additional symmetry that we refer to as mirror, or reflexional symmetry. The magnitude of drift speed in our results shows a strong variation with both mu and beta: while the drift speed decreases almost linearly with decreasing mu, it actually increases as beta decreases. Similar drifting jets are also observed in QL, with the same direction (i.e. northward or southward) and similar magnitude as NL jet-drift. Starting from the laminar solution, and assuming a mean-flow that varies slowly with reference to the scale of the eddies, we obtain

  7. Modified entropic force

    SciTech Connect

    Gao Changjun

    2010-04-15

    The theory of statistical thermodynamics tells us the equipartition law of energy does not hold in the limit of very low temperatures. It is found the Debye model is very successful in explaining the experimental results for most of the solid objects. Motivated by this fact, we modify the entropic force formula which is proposed very recently. Since the Unruh temperature is proportional to the strength of the gravitational field, so the modified entropic force formula is an extension of the Newtonian gravity to the weak field. On the contrary, general relativity extends Newtonian gravity to the strong field case. Corresponding to Debye temperature, there exists a Debye acceleration g{sub D}. It is found the Debye acceleration is g{sub D}=10{sup -15} N kg{sup -1}. This acceleration is very much smaller than the gravitational acceleration 10{sup -4} N kg{sup -1} which is felt by Neptune and the gravitational acceleration 10{sup -10} N kg{sup -1} felt by the Sun. Therefore, the modified entropic force can be very well approximated by the Newtonian gravity in the Solar System and in the Galaxy. With this Debye acceleration, we find the current cosmic speeding up can be explained without invoking any kind of dark energy.

  8. Microrheology of cells with magnetic force modulation atomic force microscopy.

    PubMed

    Rebêlo, L M; de Sousa, J S; Mendes Filho, J; Schäpe, J; Doschke, H; Radmacher, M

    2014-04-01

    We propose a magnetic force modulation method to measure the stiffness and viscosity of living cells using a modified AFM apparatus. An oscillating magnetic field makes a magnetic cantilever oscillate in contact with the sample, producing a small AC indentation. By comparing the amplitude of the free cantilever motion (A0) with the motion of the cantilever in contact with the sample (A1), we determine the sample stiffness and viscosity. To test the method, the frequency-dependent stiffness of 3T3 fibroblasts was determined as a power law k(s)(f) = α + β(f/f¯)(γ) (α = 7.6 × 10(-4) N m(-1), β = 1.0 × 10(-4) N m(-1), f¯ = 1 Hz, γ = 0.6), where the coefficient γ = 0.6 is in good agreement with rheological data of actin solutions with concentrations similar to those in cells. The method also allows estimation of the internal friction of the cells. In particular we found an average damping coefficient of 75.1 μN s m(-1) for indentation depths ranging between 1.0 μm and 2.0 μm. PMID:24651941

  9. Teaching International Law: Concepts in International Relations

    ERIC Educational Resources Information Center

    Starbird, Caroline; Pettit, Jenny; Singleton, Laurel

    2004-01-01

    This book is designed to introduce students to public international law. Topics covered include international public organizations, such as the United Nations and World Trade Organization, international courts, international human rights law, international trade law, and international environmental law. The goal of each study is to examine how…

  10. International Cooperation in Science. Science Policy Study--Hearings Volume 7. Hearings before the Task Force on Science Policy of the Committee on Science and Technology, House of Representatives, Ninety-Ninth Congress, First Session (June 18, 19, 20, 27, 1985). No. 50.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Science and Technology.

    These hearings on international cooperation in science focused on three issues: (1) international cooperation in big science; (2) the impact of international cooperation on research priorities; and (3) coordination in management of international cooperative research. Witnesses presenting testimony and/or prepared statements were: Victor Weisskopf;…

  11. Finger force perception during ipsilateral and contralateral force matching tasks

    PubMed Central

    Park, Woo-Hyung; Leonard, Charles T.; Li, Sheng

    2010-01-01

    The aims of the present study were to compare matching performance between ipsilateral and contralateral finger force matching tasks and to examine the effect of handedness on finger force perception. Eleven subjects were instructed to produce reference forces by an instructed finger (index – I or little – L finger) and to reproduce the same amount force by the same or a different finger within the hand (i.e., ipsilateral matching task), or by a finger of the other hand (i.e., contralateral matching task). The results of the ipsilateral and contralateral tasks in the present study commonly showed that 1) the reference and matching forces were matched closely when the two forces were produced by the same or homologous finger(s) such as I/I task; 2) the weaker little finger underestimated the magnitude of reference force of the index finger (I/L task), even with the higher level of effort (relative force), but the two forces were matched when considering total finger forces; 3) the stronger index finger closely matched the reference force of the little finger with the lower level of relative force (i.e., L/I task); 4) when considering the constant errors, I/L tasks showed an underestimation and L/I tasks showed an overestimation compared to I/I tasks. There was no handedness effect during ipsilateral tasks. During the contralateral task, the dominant hand overestimated the force of the non-dominant hand, while the non-dominant hand attempted to match the absolute force of the dominant hand. The overall results support the notion that the absolute, rather than relative, finger force is perceived and reproduced during ipsilateral and contralateral finger force matching tasks, indicating the uniqueness of finger force perception. PMID:18488212

  12. Force reflection with compliance control

    NASA Technical Reports Server (NTRS)

    Kim, Won S. (Inventor)

    1993-01-01

    Two types of systems for force-reflecting control, which enables high force-reflection gain, are presented: position-error-based force reflection and low-pass-filtered force reflection. Both of the systems are combined with shared compliance control. In the position-error-based class, the position error between the commanded and the actual position of a compliantly controlled robot is used to provide force reflection. In the low-pass-filtered force reflection class, the low-pass-filtered output of the compliance control is used to provide force reflection. The increase in force reflection gain can be more than 10-fold as compared to a conventional high-bandwidth pure force reflection system, when high compliance values are used for the compliance control.

  13. Probing cellular traction forces with magnetic nanowires and microfabricated force sensor arrays

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Chia; Kramer, Corinne M.; Chen, Christopher S.; Reich, Daniel H.

    2012-02-01

    In this paper, the use of magnetic nanowires for the study of cellular response to force is demonstrated. High-aspect ratio Ni rods with diameter 300 nm and lengths up to 20 μm were bound to or internalized by pulmonary artery smooth muscle cells (SMCs) cultured on arrays of flexible micropost force sensors. Forces and torques were applied to the cells by driving the nanowires with AC magnetic fields in the frequency range 0.1-10 Hz, and the changes in cellular contractile forces were recorded with the microposts. These local stimulations yield global force reinforcement of the cells’ traction forces, but this contractile reinforcement can be effectively suppressed upon addition of a calcium channel blocker, ruthenium red, suggesting the role of calcium channels in the mechanical response. The responsiveness of the SMCs to actuation depends on the frequency of the applied stimulation. These results show that the combination of magnetic nanoparticles and micropatterned, flexible substrates can provide new approaches to the study of cellular mechanotransduction.

  14. [Internal migration].

    PubMed

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  15. Adding Value to Force Diagrams: Representing Relative Force Magnitudes

    NASA Astrophysics Data System (ADS)

    Wendel, Paul

    2011-05-01

    Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area.1-4 Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams,4-6 and over recent years a rich variety of approaches has been proposed to add value to force diagrams. Suggestions include strategies for identifying candidate forces,6,7 emphasizing the distinction between "contact" and "noncontact" forces,5,8 and the use of computer-based tutorials.9,10 Instructors have suggested a variety of conventions for constructing force diagrams, including approaches to arrow placement and orientation2,11-13 and proposed notations for locating forces or marking action-reaction force pairs.8,11,14,15

  16. Using explicit macroscopic feedback to determine efficacy of climate forcings

    NASA Astrophysics Data System (ADS)

    Kravitz, B.; MacMartin, D. G.

    2013-12-01

    Calculating efficacies of climate forcings has been a useful method of determining the importance of forcing agents relative to CO2. However, because the strength of internal feedbacks is dependent upon the climate state, efficacies are dependent upon the strengths of the applied forcings, and simulations designed to capture these efficacies have tradeoffs between simulation length and accurately capturing the steady state climate response. We propose an alternate method of determining a quantity similar to climate efficacy via adjusting the amount of forcing by feeding back the observed climate state. By balancing CO2 forcing with another climate forcing, many internal feedbacks are suppressed, which linearizes the climate response to the forcing and promotes rapid convergence of the simulation. We performed simulations in two fully coupled general circulation models of Earth's climate. Doubling the present day CO2 concentration requires a steady state solar reduction of approximately 2.5%; this answer can be obtained with a simulation of less than 30 years. With this method, the amount of solar reduction scales linearly with the logarithmic change in CO2 concentration. We explore similar calculations using other climate forcings. Because this method circumvents calculation of radiative forcing, intercomparison of values between different climate forcings is difficult and is a drawback of our method as compared to the original method of calculating efficacy. Feedback can be used to estimate the efficacy of solar reductions in models. The solar reduction that is required to maintain temperature in the presence of an instantaneous change in atmospheric CO2 concentrations is computed using feedback. The left-hand panel illustrates both the solar forcing as a function of time for offsetting 2×CO2, and the efficacy estimated as the mean solar reduction after the initial transient; extremely rapid convergence is obtained. The right-hand panel illustrates the linearity

  17. Entrainment ranges of forced phase oscillators.

    PubMed

    Previte, Joseph P; Sheils, Natalie; Hoffman, Kathleen A; Kiemel, Tim; Tytell, Eric D

    2011-04-01

    In the vertebrate spinal cord, a neural circuit called the central pattern generator produces the basic locomotory rhythm. Short and long distance intersegmental connections serve to maintain coordination along the length of the body. As a way of examining the influence of such connections, we consider a model of a chain of coupled phase oscillators in which one oscillator receives a periodic forcing stimulus. For a certain range of forcing frequencies, the chain will match the stimulus frequency, a phenomenon called entrainment. Motivated by recent experiments in lampreys, we derive analytical expressions for the range of forcing frequencies that entrain the chain, and how that range depends on the forcing location. For short intersegmental connections, in which an oscillator is connected only to its nearest neighbors, we describe two ways in which entrainment is lost: internally, in which oscillators within the chain no longer oscillate at the same frequency; and externally, in which the the chain no longer has the same frequency as the forcing. By analyzing chains in which every oscillator is connected to every other oscillator (i.e., all-to-all connections), we show that the presence of connections with lengths greater than one do not necessarily change the entrainment ranges based on the nearest-neighbor model. We derive a criterion for the ratio of connection strengths under which the connections of length greater than one do not change the entrainment ranges produced in the nearest-neighbor model, provided entrainment is lost externally. However, when this criterion holds, the range of entrained frequencies is a monotonic function of forcing location, unlike experimental results, in which entrainment ranges are larger near the middle of the chain than at the ends. Numerically, we show that similar non-monotonic entrainment ranges are possible if the ratio criterion does not hold, suggesting that in the lamprey central pattern generator, intersegmental

  18. The Forces at Play in Optical Force Microscopy

    NASA Astrophysics Data System (ADS)

    Brocious, Jordan

    Optical force microscopy is a novel technique where mechanical detection with a cantilevered probe replaces the detection of photons to investigate optically induced processes and states. A theoretical and experimental analysis is performed here of the forces present in optical force microscopy operated in tapping mode, which reveals two dominant optically induced forces, the gradient force and the scattering force. Force-distance curves are reconstructed from experimental amplitude and phase information for glass, gold nanowires and molecular clusters of silicon naphtalocyanine samples. The scattering force is shown to be insensitive to both nano-scale tip-sample distances and sample polarizability and is dependent on the form of the tip. The gradient force demonstrates a z-4 tip-sample distance dependence, localized to a few nanometers, and is strongly dependent on the polarizability of the sample which enables spectroscopic imaging through force detection. The different distance-dependence and polarizability-dependence of the gradient and scattering forces give rise to a complex force-distance curve which determines imaging contrast along with the cantilever set-point, knowledge of which is essential for image interpretation.

  19. The Effects of Forced Exhalation and Inhalation, Grunting, and Valsalva Maneuver on Forehand Force in Collegiate Tennis Players.

    PubMed

    OʼConnell, Dennis G; Brewer, Jacob F; Man, Timothy H; Weldon, John S; Hinman, Martha R

    2016-02-01

    To examine the effects of forced expiration (FE), forced inspiration (FI), grunting (GR), and valsalva maneuver (VM), on air volume, maximum force production, and muscle recruitment during a simulated forehand stroke in collegiate tennis players. Superficial electrodes were placed over the anterior deltoid, pectoralis major, rectus abdominis, lumbar and thoracic erector spinae, and external and internal obliques. Subjects stood in a simulated forehand stroke stance with their dominant hand positioned on a force plate. Subjects performed 3 repetitions of maximal 2- to 3-second isometric forehands with randomly assigned breathing conditions (FE, FI, VM, and GR) and 30-seconds rest between contractions. Air volumes were also collected during each trial. A repeated-measures multivariate analysis of variance compared normalized peak electromyographic activity across the 7 muscle groups. Separate repeated measures ANOVAs compared the effect of breathing conditions on peak force production and air volume. Statistical significance was set at p ≤ 0.05 for all analyses. Overall muscle activity differed significantly by breathing condition (p = 0.031) with greater anterior deltoid activity was seen in FE and GR vs. VM. Internal oblique activity was significantly greater in GR than FI or VM, and thoracic erector spinae activity was significantly greater during FE and VM than FI. Force production did not differ significantly among breathing conditions (p = 0.74); however, GR forces were greater than FI and VM forces (p ≤ 0.05). Forced expiration air volume was significantly greater (p < 0.001) than FI, GR, or VM. These findings suggest that either GR or a more quiescent FE can be used to enhance force production. Forced expiration is a potentially safer alternative to VM and more aurally pleasing than GR. PMID:26270695

  20. Atomic Force Microscope

    SciTech Connect

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  1. Radiative forcing of climate

    NASA Technical Reports Server (NTRS)

    Ramanswamy, V.; Shine, Keith; Leovy, Conway; Wang, Wei-Chyung; Rodhe, Henning; Wuebbles, Donald J.; Ding, M.; Lelieveld, Joseph; Edmonds, Jae A.; Mccormick, M. Patrick

    1991-01-01

    An update of the scientific discussions presented in Chapter 2 of the Intergovernmental Panel on Climate Change (IPCC) report is presented. The update discusses the atmospheric radiative and chemical species of significance for climate change. There are two major objectives of the present update. The first is an extension of the discussion on the Global Warming Potentials (GWP's), including a reevaluation in view of the updates in the lifetimes of the radiatively active species. The second important objective is to underscore major developments in the radiative forcing of climate due to the observed stratospheric ozone losses occurring between 1979 and 1990.

  2. Causal Entropic Forces

    NASA Astrophysics Data System (ADS)

    Wissner-Gross, A. D.; Freer, C. E.

    2013-04-01

    Recent advances in fields ranging from cosmology to computer science have hinted at a possible deep connection between intelligence and entropy maximization, but no formal physical relationship between them has yet been established. Here, we explicitly propose a first step toward such a relationship in the form of a causal generalization of entropic forces that we find can cause two defining behaviors of the human “cognitive niche”—tool use and social cooperation—to spontaneously emerge in simple physical systems. Our results suggest a potentially general thermodynamic model of adaptive behavior as a nonequilibrium process in open systems.

  3. 47 CFR 80.86 - International regulations applicable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false International regulations applicable. 80.86...-General § 80.86 International regulations applicable. In addition to being regulated by these rules, the... provisions of all other international agreements in force to which the United States is a party....

  4. 47 CFR 80.86 - International regulations applicable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false International regulations applicable. 80.86...-General § 80.86 International regulations applicable. In addition to being regulated by these rules, the... provisions of all other international agreements in force to which the United States is a party....

  5. 47 CFR 80.86 - International regulations applicable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false International regulations applicable. 80.86...-General § 80.86 International regulations applicable. In addition to being regulated by these rules, the... provisions of all other international agreements in force to which the United States is a party....

  6. 32 CFR 536.106 - Definitions for international agreements claims.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 3 2014-07-01 2014-07-01 false Definitions for international agreements claims... CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.106 Definitions for international agreements claims. (a) Force and civilian component of...

  7. 32 CFR 536.106 - Definitions for international agreements claims.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Definitions for international agreements claims... CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.106 Definitions for international agreements claims. (a) Force and civilian component of...

  8. 32 CFR 536.106 - Definitions for international agreements claims.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Definitions for international agreements claims... CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.106 Definitions for international agreements claims. (a) Force and civilian component of...

  9. 32 CFR 536.106 - Definitions for international agreements claims.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 3 2013-07-01 2013-07-01 false Definitions for international agreements claims... CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.106 Definitions for international agreements claims. (a) Force and civilian component of...

  10. 32 CFR 536.106 - Definitions for international agreements claims.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Definitions for international agreements claims... CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.106 Definitions for international agreements claims. (a) Force and civilian component of...

  11. 47 CFR 80.86 - International regulations applicable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false International regulations applicable. 80.86...-General § 80.86 International regulations applicable. In addition to being regulated by these rules, the... provisions of all other international agreements in force to which the United States is a party....

  12. 47 CFR 80.86 - International regulations applicable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false International regulations applicable. 80.86...-General § 80.86 International regulations applicable. In addition to being regulated by these rules, the... provisions of all other international agreements in force to which the United States is a party....

  13. Longwave radiative forcing by aqueous aerosols

    SciTech Connect

    Gaffney, J.S.; Marley, N.A.

    1995-01-01

    Recently, a great deal of interest has been focused on the role of aerosols in climatic change because of their potential cooling impacts due to light scattering. Recent advances in infrared spectroscopy using cylindrical internal reflectance have allowed the longwave absorption of dissolved aerosol species and the associated liquid water to be accurately determined and evaluated. Experimental measurements using these techniques have shown that dissolved sulfate, nitrate, and numerous other aerosol species will act to cause greenhouse effects. Preliminary calculations indicate that the longwave climate forcing (i.e., heating) for sulfate aerosol will be comparable in magnitude to the cooling effect produced by light scattering. However, more detailed modeling will clearly be needed to address the impact of the longwave forcing due to aerosols as a function of atmospheric height and composition. Their work has shown that aerosol composition will be important in determining longwave forcing, while shortwave forcing will be more related to the physical size of the aerosol droplets. On the basis of these studies, it is increasingly apparent that aerosols, fogs, and clouds play a key role in determining the radiative balance of the atmosphere and in controlling regional and global climates.

  14. Interparticle Forces Underlying Nanoparticle Self-Assemblies.

    PubMed

    Luo, Dan; Yan, Cong; Wang, Tie

    2015-12-01

    Studies on the self-assembly of nanoparticles have been a hot topic in nanotechnology for decades and still remain relevant for the present and future due to their tunable collective properties as well as their remarkable applications to a wide range of fields. The novel properties of nanoparticle assemblies arise from their internal interactions and assemblies with the desired architecture key to constructing novel nanodevices. Therefore, a comprehensive understanding of the interparticle forces of nanoparticle self-assemblies is a pre-requisite to the design and control of the assembly processes, so as to fabricate the ideal nanomaterial and nanoproducts. Here, different categories of interparticle forces are classified and discussed according to their origins, behaviors and functions during the assembly processes, and the induced collective properties of the corresponding nanoparticle assemblies. Common interparticle forces, such as van der Waals forces, electrostatic interactions, electromagnetic dipole-dipole interactions, hydrogen bonds, solvophonic interactions, and depletion interactions are discussed in detail. In addition, new categories of assembly principles are summarized and introduced. These are termed template-mediated interactions and shape-complementary interactions. A deep understanding of the interactions inside self-assembled nanoparticles, and a broader perspective for the future synthesis and fabrication of these promising nanomaterials is provided. PMID:26436692

  15. Lateral Casimir force beyond the proximity-force approximation.

    PubMed

    Rodrigues, Robson B; Neto, Paulo A Maia; Lambrecht, Astrid; Reynaud, Serge

    2006-03-17

    We argue that the appropriate variable to study a nontrivial geometry dependence of the Casimir force is the lateral component of the Casimir force, which we evaluate between two corrugated metallic plates outside the validity of the proximity-force approximation. The metallic plates are described by the plasma model, with arbitrary values for the plasma wavelength, the plate separation, and the corrugation period, the corrugation amplitude remaining the smallest length scale. Our analysis shows that in realistic experimental situations the proximity-force approximation overestimates the force by up to 30%. PMID:16605712

  16. Uncertainty in NIST Force Measurements

    PubMed Central

    Bartel, Tom

    2005-01-01

    This paper focuses upon the uncertainty of force calibration measurements at the National Institute of Standards and Technology (NIST). The uncertainty of the realization of force for the national deadweight force standards at NIST is discussed, as well as the uncertainties associated with NIST’s voltage-ratio measuring instruments and with the characteristics of transducers being calibrated. The combined uncertainty is related to the uncertainty of dissemination for force transfer standards sent to NIST for calibration. PMID:27308181

  17. Force generation in a regrowing eukaryotic flagellum

    NASA Astrophysics Data System (ADS)

    Polin, Marco; Bruneau, Bastien; Johnson, Thomas; Goldstein, Raymond

    2012-02-01

    Flagella are whip-like organelles with a complex internal structure, the axoneme, highly conserved across eukaryotic species. The highly regulated activity of motor proteins arranged along the axoneme moves the flagellum in the surrounding fluid, generating forces that can be used for swimming or fluid propulsion. Although our understanding of the general mechanism behind flagellar motion is well established, the details of its implementation in a real axoneme is still poorly understood. Here we explore the inner working of the eukaryotic flagellum using a uniflagellated mutant of the unicellular green alga Chlamydomonas reinhardtii to investigate in detail the force and power generated by a moving flagellum during axonemal regrowth after deflagellation. These experiments will contribute to our understanding of the inner working of the eukaryotic flagellum.

  18. Illinois task force on global climate change

    SciTech Connect

    Griffin, B.S.

    1996-12-31

    The purpose of this report is to document progress in the areas of national policy development, emissions reduction, research and education, and adaptation, and to identify specific actions that will be undertaken to implement the Illinois state action plan. The task force has been tracking national and international climate change policy, and helping shape national policy agenda. Identification and implementation of cost-effective mitigation measures has been performed for emissions reduction. In the area of research and education, the task force is developing the capacity to measure climate change indicators, maintaining and enhancing Illinois relevant research, and strengthening climate change education. Activities relevant to adaptation to new policy include strengthening water laws and planning for adaptation. 6 figs., 4 tabs.

  19. Finite element modeling and experimentation of bone drilling forces

    NASA Astrophysics Data System (ADS)

    Lughmani, W. A.; Bouazza-Marouf, K.; Ashcroft, I.

    2013-07-01

    Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced during bone drilling. The model incorporates the dynamic characteristics involved in the process along with the accurate geometrical considerations. The average critical thrust forces and torques obtained using FE analysis, for set of machining parameters are found to be in good agreement with the experimental results.

  20. Urban search and rescue medical teams: FEMA Task Force System.

    PubMed

    Barbera, J A; Lozano, M

    1993-01-01

    Recent national and international disasters involving collapsed structures and trapped casualties (Mexico City; Armenia; Iran; Philippines; Charleston, South Carolina; Loma Prieta, California; and others) have provoked a heightened national concern for the development of an adequate capability to respond quickly and effectively to this type of calamity. The Federal Emergency Management Agency (FEMA) has responded to this need by developing an Urban Search and Rescue (US&R) Response System, a national system of multi-disciplinary task forces for rapid deployment to the site of a collapsed structure incident. Each 56-person task force includes a medical team capable of providing advanced emergency medical care both for task force members and for victims located and reached by the sophisticated search, rescue, and technical components of the task force. This paper reviews the background and development of urban search and rescue, and describes the make-up and function of the Federal Emergency Management Agency (FEMA) Task Force medical teams. PMID:10155479

  1. Pairing forces in nuclei

    SciTech Connect

    Chasman, R.R.

    1996-12-31

    In this contribution, the author mentions some features of pairing forces that are unique to nuclei and cover some areas of major interest in nuclear structure research, that involve pairing. At the level of most nuclear structure studies, nuclei are treated as consisting of two kinds of fermions (protons and neutrons) in a valence space with rather few levels. These features give rise to unique aspects of pairing forces in nuclei: (1) n-p pairing in T = 0 as well as the usual T = 1 pairing that is characteristic of like fermions; (2) a need to correct pairing calculations for the (1/N) effects that can typically be neglected in superconducting solids. An issue of current concern is the nature of the pairing interaction: several recent studies suggest a need for a density dependent form of the pairing interaction. There is a good deal of feedback between the questions of accurate calculations of pairing interactions and the form and magnitude of the pairing interaction. Finally, the authors discuss some many-body wave functions that are a generalization of the BCS wave function form, and apply them to a calculation of energy level spacings in superdeformed rotational bands.

  2. Force reflecting hand controller

    NASA Technical Reports Server (NTRS)

    Mcaffee, Douglas A. (Inventor); Snow, Edward R. (Inventor); Townsend, William T. (Inventor)

    1993-01-01

    A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

  3. Magnetic force microscopy

    PubMed Central

    Passeri, Daniele; Dong, Chunhua; Reggente, Melania; Angeloni, Livia; Barteri, Mario; Scaramuzzo, Francesca A; De Angelis, Francesca; Marinelli, Fiorenzo; Antonelli, Flavia; Rinaldi, Federica; Marianecci, Carlotta; Carafa, Maria; Sorbo, Angela; Sordi, Daniela; Arends, Isabel WCE; Rossi, Marco

    2014-01-01

    Magnetic force microscopy (MFM) is an atomic force microscopy (AFM) based technique in which an AFM tip with a magnetic coating is used to probe local magnetic fields with the typical AFM spatial resolution, thus allowing one to acquire images reflecting the local magnetic properties of the samples at the nanoscale. Being a well established tool for the characterization of magnetic recording media, superconductors and magnetic nanomaterials, MFM is finding constantly increasing application in the study of magnetic properties of materials and systems of biological and biomedical interest. After reviewing these latter applications, three case studies are presented in which MFM is used to characterize: (i) magnetoferritin synthesized using apoferritin as molecular reactor; (ii) magnetic nanoparticles loaded niosomes to be used as nanocarriers for drug delivery; (iii) leukemic cells labeled using folic acid-coated core-shell superparamagnetic nanoparticles in order to exploit the presence of folate receptors on the cell membrane surface. In these examples, MFM data are quantitatively analyzed evidencing the limits of the simple analytical models currently used. Provided that suitable models are used to simulate the MFM response, MFM can be used to evaluate the magnetic momentum of the core of magnetoferritin, the iron entrapment efficiency in single vesicles, or the uptake of magnetic nanoparticles into cells. PMID:25050758

  4. Forces Stabilizing Proteins

    PubMed Central

    Pace, C. Nick; Scholtz, J. Martin; Grimsley, Gerald R.

    2014-01-01

    The goal of this article is to summarize what has been learned about the major forces stabilizing proteins since the late 1980s when site-directed mutagenesis became possible. The following conclusions are derived from experimental studies of hydrophobic and hydrogen bonding variants. 1. Based on studies of 138 hydrophobic interaction variants in 11 proteins, burying a –CH2– group on folding contributes 1.1 ± 0.5 kcal/mol to protein stability. 2. The burial of nonpolar side chains contributes to protein stability in two ways: first, a term that depends on the removal of the side chains from water and, more importantly, the enhanced London dispersion forces that result from the tight packing in the protein interior. 3. Based on studies of 151 hydrogen bonding variants in 15 proteins, forming a hydrogen bond on folding contributes 1.1 ± 0.8 kcal/mol to protein stability. 4. The contribution of hydrogen bonds to protein stability is strongly context dependent. 5. Hydrogen bonds by side chains and peptide groups make similar contributions to protein stability. 6. Polar group burial can make a favorable contribution to protein stability even if the polar group is not hydrogen bonded. 7. Hydrophobic interactions and hydrogen bonds both make large contributions to protein stability. PMID:24846139

  5. Force-Field Parameter Fitter

    Energy Science and Technology Software Center (ESTSC)

    2015-05-27

    ParFit is a flexible and extendable framework and library of classes for fitting force-field parameters to data from high-level ab-initio calculations on the basis of deterministic and stochastic algorithms. Currently, the code is fitting MM3 and Merck force-field parameters but could easily extend to other force-field types.

  6. Electronic Force Gage for Welders

    NASA Technical Reports Server (NTRS)

    Bradley, J. W.; Gates, G.

    1983-01-01

    Welding force monitored in process. Electronic force gage uses strain gage on deformable member. Oscilloscope trace of welding force photographed and compared with standard trace during calibration and troubleshooting of resistance welding equipment. Adaptable to small scale resistance welding in electronics industry.

  7. Gradient and scattering forces in photoinduced force microscopy

    NASA Astrophysics Data System (ADS)

    Jahng, Junghoon; Brocious, Jordan; Fishman, Dmitry A.; Huang, Fei; Li, Xiaowei; Tamma, Venkata Ananth; Wickramasinghe, H. Kumar; Potma, Eric Olaf

    2014-10-01

    A theoretical and experimental analysis of the dominant forces measured in photoinduced force microscopy is presented. It is shown that when operated in the noncontact and soft-contact modes, the microscope is sensitive to the optically induced gradient force (Fg) and the scattering force (Fsc). The reconstructed force-distance curve reveals a tip-dependent scattering force in the 30-60 pN range. Whereas the scattering force is virtually insensitive to the nanoscopic tip-sample distance, the gradient force shows a z-4 dependence and is manifest only for tip-sample distances of a few nm. Measurements on glass, gold nanowires, and molecular clusters of silicon naphtalocyanine confirm that the gradient force is strongly dependent on the polarizability of the sample, enabling spectroscopic imaging through force detection. The nearly constant Fsc and the spatially dependent Fg give rise to a complex force-distance curve, which varies from point to point in the specimen and dictates the image contrast observed for a given set point of the cantilevered tip.

  8. Interfacial force sensor with force-feedback control

    SciTech Connect

    Joyce, S.A.; Houston, J.E.; Smith, B.K.

    1990-01-01

    A new interfacial force microscope capable of measuring the forces between two surfaces over the entire range of surface separations, up to contact, has been developed. The design is centered around a differential capacitance displacement sensor where the common capacitor plate is supported by torsion bars. A force-feedback control system balances the interfacial forces at the sensor, maintaining the common capacitor plate at its rest position. This control eliminates the instability which occurs with the conventional cantilever-based force sensors when the attractive force gradient exceeds the mechanical stiffness of the cantilever. The ability to measure interfacial forces at surface separations smaller than this instability point using the feedback control is demonstrated. 11 refs., 3 figs.

  9. Expanding the role of internal facility assessments

    SciTech Connect

    Kolpa, R.L.; Levenson, J.B.; Weaver, M.A.

    1996-05-01

    The US Air Force (USAF) Environmental Compliance Assessment and Management Program (ECAMP) is an effective and comprehensive system to evaluate environmental compliance at individual USAF installations. The ECAMP assessment is typically performed by a team of experts from the installation`s Major Command (MAJCOM) Headquarters, and is often augmented with technical contractor support. As directed by Air Force policy, an external ECAMP assessment is required at a minimum of every three years for each installation. In the intervening years, each installation is required to perform an internal ECAMP assessment, with its own personnel and resources. Even though team composition differs, the internal and external ECAMP assessments are likely to be very similar in scope, objectives, and deliverables. For over nine years, Argonne National Laboratory (ANL) has supported several Air Force MAJCOMs in performing their external ECAMP assessments. More recently, ANL has also had the opportunity to provide technical support and training at individual installations during their preparation and conduct of internal ECAMP assessments. From that experience, the authors have learned that the quality and value of the internal assessment is enhanced by making it a vehicle for training, planning, and interaction among organizations. Various strategies and techniques have been successfully employed to derive maximum benefit and insight from the internal assessment process. Experiences that involve expanding the scope and objectives of internal assessments to meet specific goals are presented. The expansion of scope and objectives include preassessment training, planning, and evaluator interactions as part of the overall internal assessment process.

  10. Updates on Force Limiting Improvements

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; Scharton, Terry

    2013-01-01

    The following conventional force limiting methods currently practiced in deriving force limiting specifications assume one-dimensional translation source and load apparent masses: Simple TDOF model; Semi-empirical force limits; Apparent mass, etc.; Impedance method. Uncorrelated motion of the mounting points for components mounted on panels and correlated, but out-of-phase, motions of the support structures are important and should be considered in deriving force limiting specifications. In this presentation "rock-n-roll" motions of the components supported by panels, which leads to a more realistic force limiting specifications are discussed.

  11. Parallel computation with the force

    NASA Technical Reports Server (NTRS)

    Jordan, H. F.

    1985-01-01

    A methodology, called the force, supports the construction of programs to be executed in parallel by a force of processes. The number of processes in the force is unspecified, but potentially very large. The force idea is embodied in a set of macros which produce multiproceossor FORTRAN code and has been studied on two shared memory multiprocessors of fairly different character. The method has simplified the writing of highly parallel programs within a limited class of parallel algorithms and is being extended to cover a broader class. The individual parallel constructs which comprise the force methodology are discussed. Of central concern are their semantics, implementation on different architectures and performance implications.

  12. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    1990-05-01

    This is an expanded version of the third Dirac Memorial Lecture, given in 1988 by the Nobel Laureate Abdus Salam. Salam's lecture presents an overview of the developments in modern particle physics from its inception at the turn of the century to the present theories seeking to unify all the fundamental forces. In addition, two previously unpublished lectures by Paul Dirac, and Werner Heisenberg are included. These lectures provide a fascinating insight into their approach to research and the developments in particle physics at that time. Nonspecialists, undergraduates and researchers will find this a fascinating book. It contains a clear introduction to the major themes of particle physics and cosmology by one of the most distinguished contemporary physicists.

  13. Silicon force sensor

    DOEpatents

    Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.; Burnett, Damon J.; Lantz, Jeffrey W.

    2016-07-05

    The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload upon the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.

  14. [Galileo and centrifugal force].

    PubMed

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century. PMID:25029818

  15. Force protection: today's reality.

    PubMed

    Torgerson, Ron

    2004-11-11

    Most US infrastructure and major chemical manufacturing facilities as well as their supporting utility systems are inherently vulnerable to a terrorist attack. Force protection is a military and civilian term used to protect personnel and critical facilities and assets against would-be aggressors or terrorists. The war on terrorism is a 200-300-year war. Terrorist attacks on US soil could become as common-place as in the State of Israel. It is very easy to penetrate infrastructure or plants as evidenced by vulnerability assessments performed for states, cities, plants, and military facilities by Versar and others around the country. Chemical, biological, radiological, nuclear, and explosive weapons can be readily used to attack facilities in the US. This paper will explain some of those vulnerabilities, outline the current DoD standard as it relates to vulnerability assessments, and explain how this may be used in commercial applications to deter potential aggressors. PMID:15573418

  16. Force Limit System

    NASA Technical Reports Server (NTRS)

    Pawlik, Ralph; Krause, David; Bremenour, Frank

    2011-01-01

    The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

  17. International cooperation in magnetospheric physics.

    NASA Astrophysics Data System (ADS)

    Roederer, J. G.

    International scientific cooperation in the geosciences started long ago. The main driving force was the need to make measurements simultaneously at different points of the globe. Today, especially in magnetospheric physics, there are additional reasons, one of which is the need to marshal human resources on a world-wide scale to study and understand the ever-increasing complexities of the system. The solution of "global" problems of magnetospheric physics calls for a new mission-oriented mode of work, based on a carefully planned community approach. An internationally coordinated interplay between experiment, theory and computer simulation studies is necessary, as well as a new interactive mode of sharing information and data. In this age of endemically declining budgets for basic science, the international community of magnetospheric physicists must join in an all-out effort to chart their work according to consensus priorities and it must devise strategies to transmit the excitement of their science effectively to the world public.

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

    PubMed Central

    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

  19. Normal Force and Drag Force in Magnetorheological Finishing

    SciTech Connect

    Miao, C.; Shafrir, S.N.; Lambropoulos, J.C.; Jacobs, S.D.

    2010-01-13

    The material removal in magnetorheological finishing (MRF) is known to be controlled by shear stress, tau, which equals drag force, Fd, divided by spot area, As. However, it is unclear how the normal force, Fn, affects the material removal in MRF and how the measured ratio of drag force to normal force Fd/Fn, equivalent to coefficient of friction, is related to material removal. This work studies, for the first time for MRF, the normal force and the measured ratio Fd/Fn as a function of material mechanical properties. Experimental data were obtained by taking spots on a variety of materials including optical glasses and hard ceramics with a spot-taking machine (STM). Drag force and normal force were measured with a dual load cell. Drag force decreases linearly with increasing material hardness. In contrast, normal force increases with hardness for glasses, saturating at high hardness values for ceramics. Volumetric removal rate decreases with normal force across all materials. The measured ratio Fd/Fn shows a strong negative linear correlation with material hardness. Hard materials exhibit a low “coefficient of friction”. The volumetric removal rate increases with the measured ratio Fd/Fn which is also correlated with shear stress, indicating that the measured ratio Fd/Fn is a useful measure of material removal in MRF.

  20. Microphotonic Forces from Superfluid Flow

    NASA Astrophysics Data System (ADS)

    McAuslan, D. L.; Harris, G. I.; Baker, C.; Sachkou, Y.; He, X.; Sheridan, E.; Bowen, W. P.

    2016-04-01

    In cavity optomechanics, radiation pressure and photothermal forces are widely utilized to cool and control micromechanical motion, with applications ranging from precision sensing and quantum information to fundamental science. Here, we realize an alternative approach to optical forcing based on superfluid flow and evaporation in response to optical heating. We demonstrate optical forcing of the motion of a cryogenic microtoroidal resonator at a level of 1.46 nN, roughly 1 order of magnitude larger than the radiation pressure force. We use this force to feedback cool the motion of a microtoroid mechanical mode to 137 mK. The photoconvective forces we demonstrate here provide a new tool for high bandwidth control of mechanical motion in cryogenic conditions, while the ability to apply forces remotely, combined with the persistence of flow in superfluids, offers the prospect for new applications.

  1. Force measurements during vibration testing

    SciTech Connect

    Smallwood, D.O.; Coleman, R.G.

    1993-12-31

    Experimental measurements of force into a ``rigid`` test item representing a typical system level vibration test were conducted to evaluate several methods of force measurements. The methods evaluated included: (1) Direct measurement with force gages between the test item and the fixturing; (2) Measurement of the force at the shaker/fixture interface and correcting the force required to drive the fixturing using two methods, (a) mass subtraction and (b) SWAT (sum of weighted accelerations technique), (3) Force deduced from voltage and current needed to drive the test item. All of the methods worked over a limited frequency range of five to a few hundred Hertz. The widest bandwidth was achieved with force at the shaker/fixture interface with SWAT corrections and from the voltage and current measurements.

  2. Future Air Force systems.

    PubMed

    Tremaine, S A

    1986-10-01

    Planning for the future is under way in earnest at the Aeronautical Systems Division (ASD) at Wright-Patterson Air Force Base. It has been statistically established that it takes from 14-16 years from the generation of a new system idea to enter into engineering development. With this unpleasing, but realistic, schedule in mind, ASD has, during the last 3 years, been initiating long-term planning projects that are pre-starts for new system ideas. They are generated from throughout the Air Force and are locally managed and funded. Through this process, which spans from 12-14 months, specific and revolutionary new ideas for the systems of the future are generated. This article addresses more than a dozen specific new ideas in work at ASD today. These ideas range from a need to replace the C-130 type aircraft after the year 2000 to planning a follow-on to the B-18 well into the 21st century. Among other specific projects are investigation into an immortal fighter intended to be free of reliability and maintenance demands for an especially long period of operation, a new training system and advanced trainer to replace the T-38, a transatmospheric vehicle that could operate in the 100,000-500,000 foot flight region (30,480-152,400 m), and a new means of defending against hostile cruise missile launchers and cruise missiles. Other ideas are also addressed. The article concludes with emphasis on systems that can operate hypersonically in and out of the known atmosphere and greater use of airbreathing propulsion systems operating between Mach 3 and Mach 6. PMID:3778403

  3. Vibrational spectrum and force field of dimethyldimethoxysilane

    SciTech Connect

    Tenisheva, T.F.; Lazarev, A.N.

    1986-01-01

    Experimental data is presented on the spectra of (CH/sub 3/)/sub 2/Si(OCH/sub 3/)/sub 2/ (I), (CH/sub 3/)/sub 2/Si(OCD/sub 3/)/sub 2/ (II), and (CD/sub 3/)/sub 2/Si(OCH/sub 3/)/sub 2/ (III). The results of the determination of the force constants on the basis of the optimization of the solution of the inverse mechanical problem of the theory of molecular vibrations with consideration of all the internal degrees of freedom with the exception of the coordinates corresponding to internal rotations are discussed. Raman spectra of I, II, and III in the liquid phase is shown and the IR spectra of amorphous films of I, II, and III are illustrated.

  4. Chin force in violin playing.

    PubMed

    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. PMID:21952980

  5. Exploring Sources of Variation in Studies of Knowledge Structure Coherence: Comparing Force Meanings and Force Meaning Consistency across Two Turkish Cities

    ERIC Educational Resources Information Center

    Clark, Douglas B.; Menekse, Muhsin; Ozdemir, Gokhan; D'Angelo, Cynthis M.; Price Schleigh, Sharon

    2014-01-01

    Substantial variation has been observed across an international series of studies examining the consistency of students' explanations of force and the most common meanings of force apparent in those explanations. On the surface, the variations among studies might be attributed to differences at the national level, but the studies also…

  6. Anterior Hip Joint Force Increases with Hip Extension, Decreased Gluteal Force, or Decreased Iliopsoas Force

    PubMed Central

    Lewis, Cara L.; Sahrmann, Shirley A.; Moran, Daniel W.

    2008-01-01

    Abnormal or excessive force on the anterior hip joint may cause anterior hip pain, subtle hip instability and a tear of the acetabular labrum. We propose that both the pattern of muscle force and hip joint position can affect the magnitude of anterior joint force and thus possibly lead to excessive force and injury. The purpose of this study was to determine the effect of hip joint position and of weakness of the gluteal and iliopsoas muscles on anterior hip joint force. We used a musculoskeletal model to estimate hip joint forces during simulated prone hip extension and supine hip flexion under 4 different muscle force conditions and across a range of hip extension and flexion positions. Weakness of specified muscles was simulated by decreasing the modeled maximum force value for the gluteal muscles during hip extension and the iliopsoas muscle during hip flexion. We found that decreased force contribution from the gluteal muscles during hip extension and the iliopsoas muscle during hip flexion resulted in an increase in the anterior hip joint force. The anterior hip joint force was greater when the hip was in extension than when the hip was in flexion. Further studies are warranted to determine if increased utilization of the gluteal muscles during hip extension and of the iliopsoas muscle during hip flexion, and avoidance of hip extension beyond neutral would be beneficial for people with anterior hip pain, subtle hip instability, or an anterior acetabular labral tear. PMID:17707385

  7. An Integrated Higgs Force Theory

    NASA Astrophysics Data System (ADS)

    Colella, Antonio

    2016-03-01

    An Integrated Higgs force theory (IHFT) was based on 2 key requirement amplifications: a matter particle/Higgs force was one and inseparable; a matter particle/Higgs force bidirectionally condensed/evaporated from/to super force. These were basis of 5 theories: particle creation, baryogenesis, superpartner/quark decays, spontaneous symmetry breaking, and stellar black holes. Our universe's 129 matter/force particles contained 64 supersymmetric Higgs particles; 9 transient matter particles/Higgs forces decayed to 8 permanent matter particles/Higgs forces; mass was given to a matter particle by its Higgs force and gravitons; and sum of 8 Higgs force energies of 8 permanent matter particles was dark energy. An IHFT's essence is the intimate physical relationships between 8 theories. These theories are independent because physicists in one theory worked independently of physicists in the other seven. An IHFT's premise is without sacrificing their integrities, 8 independent existing theories are replaced by 8 interrelated amplified theories. Requirement amplifications provide interfaces between the 8 theories. Intimate relationships between 8 theories including the above 5 and string, Higgs forces, and Super Universe are described. The sorting category selected was F. PARTICLES AND FIELDS (e.g., F1 Higgs Physics, F10 Alternative Beyond the Standard Model Physics, F11 Dark Sector Theories and Searches, and F12 Particle Cosmology).

  8. Theory of Casimir Forces without the Proximity-Force Approximation.

    PubMed

    Lapas, Luciano C; Pérez-Madrid, Agustín; Rubí, J Miguel

    2016-03-18

    We analyze both the attractive and repulsive Casimir-Lifshitz forces recently reported in experimental investigations. By using a kinetic approach, we obtain the Casimir forces from the power absorbed by the materials. We consider collective material excitations through a set of relaxation times distributed in frequency according to a log-normal function. A generalized expression for these forces for arbitrary values of temperature is obtained. We compare our results with experimental measurements and conclude that the model goes beyond the proximity-force approximation. PMID:27035293

  9. Theory of Casimir Forces without the Proximity-Force Approximation

    NASA Astrophysics Data System (ADS)

    Lapas, Luciano C.; Pérez-Madrid, Agustín; Rubí, J. Miguel

    2016-03-01

    We analyze both the attractive and repulsive Casimir-Lifshitz forces recently reported in experimental investigations. By using a kinetic approach, we obtain the Casimir forces from the power absorbed by the materials. We consider collective material excitations through a set of relaxation times distributed in frequency according to a log-normal function. A generalized expression for these forces for arbitrary values of temperature is obtained. We compare our results with experimental measurements and conclude that the model goes beyond the proximity-force approximation.

  10. Automated force controller for amplitude modulation atomic force microscopy.

    PubMed

    Miyagi, Atsushi; Scheuring, Simon

    2016-05-01

    Atomic Force Microscopy (AFM) is widely used in physics, chemistry, and biology to analyze the topography of a sample at nanometer resolution. Controlling precisely the force applied by the AFM tip to the sample is a prerequisite for faithful and reproducible imaging. In amplitude modulation (oscillating) mode AFM, the applied force depends on the free and the setpoint amplitudes of the cantilever oscillation. Therefore, for keeping the applied force constant, not only the setpoint amplitude but also the free amplitude must be kept constant. While the AFM user defines the setpoint amplitude, the free amplitude is typically subject to uncontrollable drift, and hence, unfortunately, the real applied force is permanently drifting during an experiment. This is particularly harmful in biological sciences where increased force destroys the soft biological matter. Here, we have developed a strategy and an electronic circuit that analyzes permanently the free amplitude of oscillation and readjusts the excitation to maintain the free amplitude constant. As a consequence, the real applied force is permanently and automatically controlled with picoNewton precision. With this circuit associated to a high-speed AFM, we illustrate the power of the development through imaging over long-duration and at various forces. The development is applicable for all AFMs and will widen the applicability of AFM to a larger range of samples and to a larger range of (non-specialist) users. Furthermore, from controlled force imaging experiments, the interaction strength between biomolecules can be analyzed. PMID:27250433

  11. The Effects of Forced Sexual Intercourse on White Female Adolescents.

    ERIC Educational Resources Information Center

    Miller, Brent C.; And Others

    1995-01-01

    Psychological and sexual variables were compared for white women, ages 18 through 22, who did (n=41) or did not (n=400) report prior forced sexual intercourse (FSI). Those who had FSI had lower internal locus of control and higher depression scores and needed and received more psychological help than those not reporting FSI. (Author/SW)

  12. Ground reaction forces during treadmill running in microgravity.

    PubMed

    De Witt, John K; Ploutz-Snyder, Lori L

    2014-07-18

    Astronauts perform treadmill exercise during long-duration space missions to counter the harmful effects of microgravity exposure upon bone, muscle, and cardiopulmonary health. When exercising in microgravity, astronauts wear a harness and bungee system that provides forces that maintain attachment to the treadmill. Typical applied forces are less than body weight. The decreased gravity-replacement force could result in differences in ground-reaction force at a given running speed when compared to those achieved in normal gravity, which could influence the adaptive response to the performed exercise. Seven astronauts (6 m/1 f) who completed approximately 6-month missions on the International Space Station (ISS) completed a preflight (1G) and multiple in-flight (0G) data collection sessions. Ground-reaction forces were measured during running at speeds of 8.0 kph and greater on an instrumented treadmill in the lab and on the ISS. Ground-reaction forces in 0G were less than in 1G for a given speed depending upon the gravity-replacement force, but did increase with increased speed and gravity-replacement force. Ground-reaction forces attained in 1G during slower running could be attained by increasing running speed and/or increasing gravity-replacement forces in 0G. Loading rates in 1G, however, could not be replicated in 0G. While current gravity-replacement force devices are limited in load delivery magnitude, we recommend increasing running speeds to increase the mechanical loads applied to the musculoskeletal system during 0G treadmill exercise, and to potentially increase exercise session efficiency. PMID:24835563

  13. Tunneling magnetic force microscopy

    NASA Technical Reports Server (NTRS)

    Burke, Edward R.; Gomez, Romel D.; Adly, Amr A.; Mayergoyz, Isaak D.

    1993-01-01

    We have developed a powerful new tool for studying the magnetic patterns on magnetic recording media. This was accomplished by modifying a conventional scanning tunneling microscope. The fine-wire probe that is used to image surface topography was replaced with a flexible magnetic probe. Images obtained with these probes reveal both the surface topography and the magnetic structure. We have made a thorough theoretical analysis of the interaction between the probe and the magnetic fields emanating from a typical recorded surface. Quantitative data about the constituent magnetic fields can then be obtained. We have employed these techniques in studies of two of the most important issues of magnetic record: data overwrite and maximizing data-density. These studies have shown: (1) overwritten data can be retrieved under certain conditions; and (2) improvements in data-density will require new magnetic materials. In the course of these studies we have developed new techniques to analyze magnetic fields of recorded media. These studies are both theoretical and experimental and combined with the use of our magnetic force scanning tunneling microscope should lead to further breakthroughs in the field of magnetic recording.

  14. Deep atomic force microscopy

    SciTech Connect

    Barnard, H.; Drake, B.; Randall, C.; Hansma, P. K.

    2013-12-15

    The Atomic Force Microscope (AFM) possesses several desirable imaging features including the ability to produce height profiles as well as two-dimensional images, in fluid or air, at high resolution. AFM has been used to study a vast selection of samples on the scale of angstroms to micrometers. However, current AFMs cannot access samples with vertical topography of the order of 100 μm or greater. Research efforts have produced AFM scanners capable of vertical motion greater than 100 μm, but commercially available probe tip lengths are still typically less than 10 μm high. Even the longest probe tips are below 100 μm and even at this range are problematic. In this paper, we present a method to hand-fabricate “Deep AFM” probes with tips of the order of 100 μm and longer so that AFM can be used to image samples with large scale vertical topography, such as fractured bone samples.

  15. Maximum bow force revisited.

    PubMed

    Mores, Robert

    2016-08-01

    Schelleng [J. Acoust. Soc. Am. 53, 26-41 (1973)], Askenfelt [J. Acoust. Soc. Am. 86, 503-516 (1989)], Schumacher [J. Acoust. Soc. Am. 96, 1985-1998 (1994)], and Schoonderwaldt, Guettler, and Askenfelt [Acta Acust. Acust. 94, 604-622 (2008)] formulated-in different ways-how the maximum bow force relates to bow velocity, bow-bridge distance, string impedance, and friction coefficients. Issues of uncertainty are how to account for friction or for the rotational admittance of the strings. Related measurements at the respective transitions between regimes of Helmholtz motion and non-Helmholtz motion employ a variety of bowing machines and stringed instruments. The related findings include all necessary parameters except the friction coefficients, leaving the underlying models unconfirmed. Here, a bowing pendulum has been constructed which allows precise measurement of relevant bowing parameters, including the friction coefficients. Two cellos are measured across all strings for three different bow-bridge distances. The empirical data suggest that-taking the diverse elements of existing models as options-Schelleng's model combined with Schumacher's velocity term yields the best fit. Furthermore, the pendulum employs a bow driving mechanism with adaptive impedance which discloses that mentioned regimes are stable and transitions between them sometimes require a hysteresis on related parameters. PMID:27586745

  16. Force Limited Vibration Testing Monograph

    NASA Technical Reports Server (NTRS)

    Scharton, Terry D.

    1997-01-01

    The practice of limiting the shaker force in vibration tests was investigated at the NASA Jet Propulsion Laboratory (JPL) in 1990 after the mechanical failure of an aerospace component during a vibration test. Now force limiting is used in almost every major vibration test at JPL and in many vibration tests at NASA Goddard Space Flight Center (GSFC) and at many aerospace contractors. The basic ideas behind force limiting have been in the literature for several decades, but the piezo-electric force transducers necessary to conveniently implement force limiting have been available only in the last decade. In 1993, funding was obtained from the NASA headquarters Office of Chief Engineer to develop and document the technology needed to establish force limited vibration testing as a standard approach available to all NASA centers and aerospace contractors. This monograph is the final report on that effort and discusses the history, theory, and applications of the method in some detail.

  17. Oil, Earth mass and gravitational force.

    PubMed

    Moustafa, Khaled

    2016-04-01

    Fossil fuels are intensively extracted from around the world faster than they are renewed. Regardless of direct and indirect effects of such extractions on climate change and biosphere, another issue relating to Earth's internal structure and Earth mass should receive at least some interest. According to the Energy Information Administration (EIA), about 34 billion barrels of oil (~4.7 trillion metric tons) and 9 billion tons of coal have been extracted in 2014 worldwide. Converting the amounts of oil and coal extracted over the last 3 decades and their respective reserves, intended to be extracted in the future, into mass values suggests that about 355 trillion tons, or ~5.86∗10(-9) (~0.0000000058)% of the Earth mass, would be 'lost'. Although this is a tiny percentage, modeling the potential loss of Earth mass may help figuring out a critical threshold of mass loss that should not be exceeded. Here, I briefly discuss whether such loss would have any potential consequences on the Earth's internal structure and on its gravitational force based on the Newton's law of gravitation that links the attraction force between planets to their respective masses and the distance that separate them. PMID:26850858

  18. Defining International Education.

    ERIC Educational Resources Information Center

    Hansen, Holly Moran

    2002-01-01

    Discusses the three facets of international education: international studies, international education exchange, and technical assistance. Also explores the effects of internationalizing higher education and the present state of international education. (EV)

  19. Entropic force and entanglement system

    SciTech Connect

    Myung, Yun Soo; Kim, Yong-Wan

    2010-05-15

    We introduce the isothermal cavity, static holographic screen, and accelerating surface as holographic screen to study the entropic force in the presence of the Schwarzschild black hole. These may merge to provide a consistent holographic screen to define the entropic force on the stretched horizon near the event horizon. Considering the similarity between the stretched horizon of black hole and the entanglement system, we may define the entropic force in the entanglement system without referring to the source mass.

  20. Coaxial atomic force microscope tweezers

    NASA Astrophysics Data System (ADS)

    Brown, K. A.; Aguilar, J. A.; Westervelt, R. M.

    2010-03-01

    We demonstrate coaxial atomic force microscope (AFM) tweezers that can trap and place small objects using dielectrophoresis (DEP). An attractive force is generated at the tip of a coaxial AFM probe by applying a radio frequency voltage between the center conductor and a grounded shield; the origin of the force is found to be DEP by measuring the pull-off force versus applied voltage. We show that the coaxial AFM tweezers can perform three-dimensional assembly by picking up a specified silica microsphere, imaging with the microsphere at the end of the tip, and placing it at a target destination.

  1. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V.; Wang, Chengpu

    2004-11-16

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  2. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V. C.; Wang, Chengpu

    2006-08-22

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  3. Force As A Momentum Current

    SciTech Connect

    Munera, Hector A.

    2010-07-28

    Advantages of a neo-Cartesian approach to classical mechanics are noted. If conservation of linear momentum is the fundamental principle, Newton's three laws become theorems. A minor paradox in static Newtonian mechanics is identified, and solved by reinterpreting force as a current of momentum. Contact force plays the role of a mere midwife in the exchange of momentum; however, force cannot be eliminated from physics because it provides the numerical value for momentum current. In this sense, in a neo-Cartesian formulation of mechanics the concept of force becomes strengthened rather than weakened.

  4. Adding Value to Force Diagrams: Representing Relative Force Magnitudes

    ERIC Educational Resources Information Center

    Wendel, Paul

    2011-01-01

    Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area. Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams, and over recent years a rich variety of…

  5. Bacterial adhesion force quantification by fluidic force microscopy

    NASA Astrophysics Data System (ADS)

    Potthoff, Eva; Ossola, Dario; Zambelli, Tomaso; Vorholt, Julia A.

    2015-02-01

    Quantification of detachment forces between bacteria and substrates facilitates the understanding of the bacterial adhesion process that affects cell physiology and survival. Here, we present a method that allows for serial, single bacterial cell force spectroscopy by combining the force control of atomic force microscopy with microfluidics. Reversible bacterial cell immobilization under physiological conditions on the pyramidal tip of a microchanneled cantilever is achieved by underpressure. Using the fluidic force microscopy technology (FluidFM), we achieve immobilization forces greater than those of state-of-the-art cell-cantilever binding as demonstrated by the detachment of Escherichia coli from polydopamine with recorded forces between 4 and 8 nN for many cells. The contact time and setpoint dependence of the adhesion forces of E. coli and Streptococcus pyogenes, as well as the sequential detachment of bacteria out of a chain, are shown, revealing distinct force patterns in the detachment curves. This study demonstrates the potential of the FluidFM technology for quantitative bacterial adhesion measurements of cell-substrate and cell-cell interactions that are relevant in biofilms and infection biology.Quantification of detachment forces between bacteria and substrates facilitates the understanding of the bacterial adhesion process that affects cell physiology and survival. Here, we present a method that allows for serial, single bacterial cell force spectroscopy by combining the force control of atomic force microscopy with microfluidics. Reversible bacterial cell immobilization under physiological conditions on the pyramidal tip of a microchanneled cantilever is achieved by underpressure. Using the fluidic force microscopy technology (FluidFM), we achieve immobilization forces greater than those of state-of-the-art cell-cantilever binding as demonstrated by the detachment of Escherichia coli from polydopamine with recorded forces between 4 and 8 nN for many

  6. Atomic Force Microscope Operation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation (large file)

    This animation is a scientific illustration of the operation of NASA's Phoenix Mars Lander's Atomic Force Microscope, or AFM. The AFM is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer, or MECA.

    The AFM is used to image the smallest Martian particles using a very sharp tip at the end of one of eight beams.

    The beam of the AFM is set into vibration and brought up to the surface of a micromachined silicon substrate. The substrate has etched in it a series of pits, 5 micrometers deep, designed to hold the Martian dust particles.

    The microscope then maps the shape of particles in three dimensions by scanning them with the tip.

    At the end of the animation is a 3D representation of the AFM image of a particle that was part of a sample informally called 'Sorceress.' The sample was delivered to the AFM on the 38th Martian day, or sol, of the mission (July 2, 2008).

    The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate.

    A Martian particle only one micrometer, or one millionth of a meter, across is held in the upper left pit.

    The rounded particle shown at the highest magnification ever seen from another world is a particle of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

    The AFM was developed by a Swiss-led consortium, with Imperial College London producing the silicon substrate that holds sampled particles.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. International data base.

    PubMed

    Quick, S

    1984-12-01

    The concept of the International Data Base (IDB) grew from recognition of the need for timely, high quality information on the demographic, social and economic characteristics of foreign countries. During the past 2 decades, the Bureau of the Census, US Department of Commerce, has been compiling, analyzing and evaluating international demographic data and, to a lesser extent, socioeconomic data with particular emphasis on developing countries. In 1979, at the request of the Office of Women in Development at the Agency for International Development, a computerized data base of demographic and socioeconomic statistics that could be used to assess the status of women in developing countries was established. The major categories of data now being included in IDB are as follows: population by age and sex; vital rates, infant mortality and life tables; health and nutrition; fertility and child survivorship; migration; provinces and cities; family planning; ethnic, religious and language groups; literacy and education; labor force, employment, income and gross national product; and household size and housing indicators. The Bureau, through its Center for International Reserch (CIR), developed a computerized central depository of demographic, social and economic data for all countries of the world to serve the needs of the public and private sectors. The initial emphasis was on demographic and social data, since these subject areas are those for which a vast amount of data has already been compiled, analyzed and evaluated by CIR staff. However, meetings are being planned with users to determine the additional types of data that are desired, particularly in the economic and health-related areas. IDB includes data for all countries of the world, by urban and rural residence. The time coverage is from 1950 to the present. Data sources include: population and industrial censuses and surveys, administrative records, population registers, statistical publications, research

  8. Interpretation and use of FRAX in clinical practice - position paper of the International Osteoporosis Foundation and the International Society for Clinical Densitometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Osteoporosis Foundation (IOF) and the International Society for Clinical Densitometry (ISCD) appointed a joint Task Force to develop resource documents in order to make recommendations on how to improve FRAX and better inform clinicians who use FRAX. The Task Force met in November...

  9. Integrated force method versus displacement method for finite element analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, S. N.; Berke, L.; Gallagher, R. H.

    1991-01-01

    A novel formulation termed the integrated force method (IFM) has been developed in recent years for analyzing structures. In this method all the internal forces are taken as independent variables, and the system equilibrium equations (EEs) are integrated with the global compatibility conditions (CCs) to form the governing set of equations. In IFM the CCs are obtained from the strain formulation of St. Venant, and no choices of redundant load systems have to be made, in constrast to the standard force method (SFM). This property of IFM allows the generation of the governing equation to be automated straightforwardly, as it is in the popular stiffness method (SM). In this report IFM and SM are compared relative to the structure of their respective equations, their conditioning, required solution methods, overall computational requirements, and convergence properties as these factors influence the accuracy of the results. Overall, this new version of the force method produces more accurate results than the stiffness method for comparable computational cost.

  10. Integrated force method versus displacement method for finite element analysis

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Berke, Laszlo; Gallagher, Richard H.

    1990-01-01

    A novel formulation termed the integrated force method (IFM) has been developed in recent years for analyzing structures. In this method all the internal forces are taken as independent variables, and the system equilibrium equations (EE's) are integrated with the global compatibility conditions (CC's) to form the governing set of equations. In IFM the CC's are obtained from the strain formulation of St. Venant, and no choices of redundant load systems have to be made, in constrast to the standard force method (SFM). This property of IFM allows the generation of the governing equation to be automated straightforwardly, as it is in the popular stiffness method (SM). In this report IFM and SM are compared relative to the structure of their respective equations, their conditioning, required solution methods, overall computational requirements, and convergence properties as these factors influence the accuracy of the results. Overall, this new version of the force method produces more accurate results than the stiffness method for comparable computational cost.

  11. Exotic nuclei and nuclear forces

    NASA Astrophysics Data System (ADS)

    Otsuka, Takaharu

    2013-01-01

    I overview new aspects of the structure of exotic nuclei as compared to stable nuclei, focusing on several characteristic effects of nuclear forces. The shell structure of nuclei has been proposed by Mayer and Jensen, and has been considered to be kept valid basically for all nuclei, with well-known magic numbers, 2, 8, 20, 28, 50, …. Nuclear forces were shown, very recently, to change this paradigm. It will be presented that the evolution of shell structure occurs in various ways as more neutrons and/or protons are added, and I will present basic points of this shell evolution in terms of the monopole interaction of nuclear forces. I will discuss three types of nuclear forces. The first one is the tensor force. The tensor force is one of the most fundamental nuclear forces, but its first-order effect on the shell structure has been clarified only recently in studies on exotic nuclei. The tensor force can change the spin-orbit splitting depending on the occupation of specific orbits. This results in changes of the shell structure in many nuclei, and consequently some of Mayer-Jensen's magic numbers are lost and new ones emerge, in certain nuclei. This mechanism can be understood in an intuitive way, meaning that the effect is general and robust. The second type of nuclear forces is central force. I will show a general but unknown property of the central force in the shell-model Hamiltonian that can describe nuclear properties in a good agreement with experiment. I will then demonstrate how it can be incorporated into a simple model of the central force, and will discuss how this force works in the shell evolution. Actually, by combining this central force with the tensor force, one can understand and foresee how the same proton-neutron interaction drives the shell evolution, for examples such as Sn/Sb isotopes, N = 20 nuclei and Ni/Cu isotopes. The distribution of single-particle strength is discussed also in comparison to (e,e‧p) experiment on 48Ca. The shell

  12. Collaborative International Education: Reaching across Borders

    ERIC Educational Resources Information Center

    Hilgers, Michael G.; Flachsbart, Barry B.; Elrod, Cassandra C.

    2012-01-01

    Purpose: As international boundaries fade and financial pressures increase, universities are redefining the norm in educational models. The move from a synchronous classroom to a blended classroom or a completely asynchronous environment has forced faculty to be creative in delivery while overcoming complexities in the associated infrastructure.…

  13. International Learning Institutions: Organization, Visions, and Missions

    ERIC Educational Resources Information Center

    Van Hook, Steven R.

    2011-01-01

    This doctoral research examines the challenges, objectives, goals, strategies, and tactics facing leaders, administrators, faculty, students, and other stakeholders with an interest in international higher education. These broad topics necessarily encompass many factors including the market forces of globalization, increasing competition,…

  14. Indonesia: Internal Conditions, the Global Economy, and Regional Development.

    ERIC Educational Resources Information Center

    Leitner, Helga; Sheppard, Eric S.

    1987-01-01

    Describes recent trends in the economic and regional development of Indonesia and examines the internal and external forces influencing the process. Shows how these forces account for the rise of a strong centralized state. Discusses Indonesia's current problems. Includes tables, maps, and graphs of economic investment figures, world trade, and…

  15. The Forced Hard Spring Equation

    ERIC Educational Resources Information Center

    Fay, Temple H.

    2006-01-01

    Through numerical investigations, various examples of the Duffing type forced spring equation with epsilon positive, are studied. Since [epsilon] is positive, all solutions to the associated homogeneous equation are periodic and the same is true with the forcing applied. The damped equation exhibits steady state trajectories with the interesting…

  16. Hebrew as a Binding Force.

    ERIC Educational Resources Information Center

    Fischler, Ben-Zion

    1990-01-01

    The role of the Hebrew language as a cohesive force and the history of modern Hebrew instruction are chronicled. It is proposed that despite the scattering of its speakers and periods of use only as a literary or business language, Hebrew has been a binding force for the Jewish people. It was with considerable struggle that Hebrew gained…

  17. Pseudo force acting between bodies

    NASA Astrophysics Data System (ADS)

    Baruah, Abhinav Ray; Deva, Anish; Sarma, Arun

    It has been shown that a non-contact force acts between two macroscopic physical objects held close together, which is not associated with the gravitational and electrostatic force. An experiment was conducted with objects of different mass, material and geometry to find the magnitude and properties of this apparent or pseudo force. The order of magnitude was found to be 10-5 and it remained constant for all types of objects while only the coefficient increased as the distance between the objects reduced. It only started acting at small distances and failed to make a body move if it experienced static friction from any contact surface. The nature of the force was found to be attractive as well as repulsive. Due to gravitation being a solely attractive force, it was eliminated as a possible reason for the pseudo force. The experiment was performed twice, once by grounding the apparatus and then again without grounding. The order of the force remained the same for both cases. As the test objects were held by hand, they were grounded through the human body. Also, none of the objects used were in contact with each other for the duration of this work, preventing any contact electrification. Due to these factors, the force was not considered electrostatic in nature.

  18. How Does Force Affect Motion?

    ERIC Educational Resources Information Center

    Darling, Gerald

    2012-01-01

    Whether playing soccer at recess, walking to lunch, or sitting at their desk, children encounter forces every moment of their lives. The connection between force and motion is absolutely amazing to children, so anyone working with them better be prepared for the battery of tough questions they ask: "What made the ball move that way? Why does a…

  19. Force Generation by Flapping Foils

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, P. R.; Donnelly, M.

    1996-11-01

    Aquatic animals like fish use flapping caudal fins to produce axial and cross-stream forces. During WW2, German scientists had built and tested an underwater vehicle powered by similar flapping foils. We have examined the forces produced by a pair of flapping foils. We have examined the forced produced by a pair of flapping foils attached to the tail end of a small axisymmetric cylinder. The foils operate in-phase (called waving), or in anti-phase (called clapping). In a low-speed water tunnel, we have undertaken time-dependent measurements of axial and cross-stream forces and moments that are exerted by the vortex shedding process over the entire body. Phase-matched LDV measurements of vorticity-velocity vectors, as well as limited flow visualization of the periodic vortex shedding process have also been carried out. The direction of the induced velocity within a pair of shed vortices determines the nature of the forces produced, viz., thrust or drag or cross-stream forces. The clapping mode produces a widely dispersed symmetric array of vortices which results in axial forces only (thrust and rag). On the other hand, the vortex array is staggered in the waving mode and cross-stream (maneuvering) forces are then generated.

  20. Dielectrophoresis force of colloidal nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Hao; Ou-Yang, Daniel

    Dielectrophoresis (DEP) is the motion of a polarizable colloidal particle in a non­uniform electric field. The magnitude of the DEP force is known to be proportional to the gradient of E2. The DEP force also depends on the relative polarizability of the particle to that of the surrounding medium. Due to its ease of use, DEP has been proposed for a variety of applications to manipulate colloidal particles in a microfluidic setting. However, accurate measurements of the DEP force on colloidal nanoparticles are lacking. A new method is proposed to measure accurately the DEP potential force of colloidal nanoparticles by using confocal fluorescence imaging to determine the density distributions of dilute colloidal nanoparticle in a DEP potential force field. The DEP potential field can be calculated from the particle density distributions since the spatial distribution of the particle number density follows the Boltzmann distribution of the DEP potential energy. The validity of the measured DEP force is tested by examining the force as a function of the E field strength and particle size. The classic Maxwell­Wagner­O'Konski is found to be inadequate to fully describe the frequency dependence of the DEP force. NSF 0928299, Emulsion Polymer Institute, Department of Physics of Lehigh University.

  1. International migration: a global challenge.

    PubMed

    Martin, P; Widgren, J

    1996-04-01

    Trends in international migration are presented in this multiregional analysis. Seven of the world's wealthiest countries have about 33% of the world's migrant population, but under 16% of the total world population. Population growth in these countries is substantially affected by the migrant population. The migration challenge is external and internal. The external challenge is to balance the need for foreign labor and the commitment to human rights for those migrants seeking economic opportunity and political freedom. The internal challenge is to assure the social adjustment of immigrants and their children and to integrate them into society as citizens and future leaders. Why people cross national borders and how migration flows are likely to evolve over the next decades are explained. This report also presents some ways that countries can manage migration or reduce the pressures which force people to migrate. It is recommended that receiving nations control immigration by accelerating global economic growth and reducing wars and human rights violations. This report examines the impact of immigration on international trade, aid, and direct intervention policies. Although migration is one of the most important international economic issues, it is not coordinated by an international group. The European experience indicates that it is not easy to secure international cooperation on issues that affect national sovereignty. It is suggested that countries desiring control of their borders should remember that most people never cross national borders to live or work in another country, that 50% of the world's migrants move among developing countries, and that countries can shift from being emigration to immigration countries. The author suggests that sustained reductions in migration pressure are a better alternative than the "quick fixes" that may invite the very much feared mass and unpredictable movements. PMID:12320315

  2. Entropic forces in Brownian motion

    NASA Astrophysics Data System (ADS)

    Roos, Nico

    2014-12-01

    Interest in the concept of entropic forces has risen considerably since Verlinde proposed in 2011 to interpret the force in Newton's second law and gravity as entropic forces. Brownian motion—the motion of a small particle (pollen) driven by random impulses from the surrounding molecules—may be the first example of a stochastic process in which such forces are expected to emerge. In this article, it is shown that at least two types of entropic force can be identified in three-dimensional Brownian motion. This analysis yields simple derivations of known results of Brownian motion, Hooke's law, and—applying an external (non-radial) force—Curie's law and the Langevin-Debye equation.

  3. Nonadditivity of critical Casimir forces

    NASA Astrophysics Data System (ADS)

    Paladugu, Sathyanarayana; Callegari, Agnese; Tuna, Yazgan; Barth, Lukas; Dietrich, Siegfried; Gambassi, Andrea; Volpe, Giovanni

    2016-04-01

    In soft condensed matter physics, effective interactions often emerge due to the spatial confinement of fluctuating fields. For instance, microscopic particles dissolved in a binary liquid mixture are subject to critical Casimir forces whenever their surfaces confine the thermal fluctuations of the order parameter of the solvent close to its critical demixing point. These forces are theoretically predicted to be nonadditive on the scale set by the bulk correlation length of the fluctuations. Here we provide direct experimental evidence of this fact by reporting the measurement of the associated many-body forces. We consider three colloidal particles in optical traps and observe that the critical Casimir force exerted on one of them by the other two differs from the sum of the forces they exert separately. This three-body effect depends sensitively on the distance from the critical point and on the chemical functionalisation of the colloid surfaces.

  4. Gene regulation by mechanical forces

    NASA Technical Reports Server (NTRS)

    Oluwole, B. O.; Du, W.; Mills, I.; Sumpio, B. E.

    1997-01-01

    Endothelial cells are subjected to various mechanical forces in vivo from the flow of blood across the luminal surface of the blood vessel. The purpose of this review was to examine the data available on how these mechanical forces, in particular cyclic strain, affect the expression and regulation of endothelial cell function. Studies from various investigators using models of cyclic strain in vitro have shown that various vasoactive mediators such as nitric oxide and prostacyclin are induced by the effect of mechanical deformation, and that the expression of these mediators may be regulated at the transcription level by mechanical forces. There also seems to be emerging evidence that endothelial cells may also act as mechanotransducers, whereby the transmission of external forces induces various cytoskeletal changes and second messenger cascades. Furthermore, it seems these forces may act on specific response elements of promoter genes.

  5. Nonadditivity of critical Casimir forces.

    PubMed

    Paladugu, Sathyanarayana; Callegari, Agnese; Tuna, Yazgan; Barth, Lukas; Dietrich, Siegfried; Gambassi, Andrea; Volpe, Giovanni

    2016-01-01

    In soft condensed matter physics, effective interactions often emerge due to the spatial confinement of fluctuating fields. For instance, microscopic particles dissolved in a binary liquid mixture are subject to critical Casimir forces whenever their surfaces confine the thermal fluctuations of the order parameter of the solvent close to its critical demixing point. These forces are theoretically predicted to be nonadditive on the scale set by the bulk correlation length of the fluctuations. Here we provide direct experimental evidence of this fact by reporting the measurement of the associated many-body forces. We consider three colloidal particles in optical traps and observe that the critical Casimir force exerted on one of them by the other two differs from the sum of the forces they exert separately. This three-body effect depends sensitively on the distance from the critical point and on the chemical functionalisation of the colloid surfaces. PMID:27097797

  6. Nonadditivity of critical Casimir forces

    PubMed Central

    Paladugu, Sathyanarayana; Callegari, Agnese; Tuna, Yazgan; Barth, Lukas; Dietrich, Siegfried; Gambassi, Andrea; Volpe, Giovanni

    2016-01-01

    In soft condensed matter physics, effective interactions often emerge due to the spatial confinement of fluctuating fields. For instance, microscopic particles dissolved in a binary liquid mixture are subject to critical Casimir forces whenever their surfaces confine the thermal fluctuations of the order parameter of the solvent close to its critical demixing point. These forces are theoretically predicted to be nonadditive on the scale set by the bulk correlation length of the fluctuations. Here we provide direct experimental evidence of this fact by reporting the measurement of the associated many-body forces. We consider three colloidal particles in optical traps and observe that the critical Casimir force exerted on one of them by the other two differs from the sum of the forces they exert separately. This three-body effect depends sensitively on the distance from the critical point and on the chemical functionalisation of the colloid surfaces. PMID:27097797

  7. Kelvin Probe Force Microscopy by Dissipative Electrostatic Force Modulation

    NASA Astrophysics Data System (ADS)

    Miyahara, Yoichi; Topple, Jessica; Schumacher, Zeno; Grutter, Peter

    2015-11-01

    We report an experimental technique for Kelvin probe force microscopy using the dissipation signal of frequency-modulation atomic force microscopy for bias-voltage feedback. It features a simple implementation and faster scanning as it requires no low-frequency modulation. The dissipation is caused by the oscillating electrostatic force that is coherent with the tip oscillation, which is induced by a sinusoidally oscillating voltage applied between the tip and sample. We analyze the effect of the phase of the oscillating force on the frequency shift and dissipation and found that the relative phase of 90° that causes only the dissipation is the most appropriate for Kelvin-probe-force-microscopy measurements. The present technique requires a significantly smaller ac-voltage amplitude by virtue of enhanced force detection due to the resonance enhancement and the use of fundamental flexural-mode oscillation for electrostatic force detection. This feature will be of great importance in the electrical characterizations of technically relevant materials whose electrical properties are influenced by the externally applied electric field as is the case in semiconductor electronic devices.

  8. Black carbon radiative forcing over the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    He, Cenlin; Li, Qinbin; Liou, Kuo-Nan; Takano, Yoshi; Gu, Yu; Qi, Ling; Mao, Yuhao; Leung, L. Ruby

    2014-11-01

    We estimate the snow albedo forcing and direct radiative forcing (DRF) of black carbon (BC) in the Tibetan Plateau using a global chemical transport model in conjunction with a stochastic snow model and a radiative transfer model. The annual mean BC snow albedo forcing is 2.9 W m-2 averaged over snow-covered plateau regions, which is a factor of 3 larger than the value over global land snowpack. BC-snow internal mixing increases the albedo forcing by 40-60% compared with external mixing, and coated BC increases the forcing by 30-50% compared with uncoated BC aggregates, whereas Koch snowflakes reduce the forcing by 20-40% relative to spherical snow grains. The annual BC DRF at the top of the atmosphere is 2.3 W m-2 with uncertainties of -70-85% in the plateau after scaling the modeled BC absorption optical depth to Aerosol Robotic Network observations. The BC forcings are attributed to emissions from different regions.

  9. Black Carbon Radiative Forcing over the Tibetan Plateau

    SciTech Connect

    He, Cenlin; Li, Qinbin; Liou, K. N.; Takano, Y.; Gu, Yu; Qi, L.; Mao, Yuhao; Leung, Lai-Yung R.

    2014-11-28

    We estimate the snow albedo forcing and direct radiative forcing (DRF) of black carbon (BC) in the Tibetan Plateau using a global chemical transport model in conjunction with a stochastic snow model and a radiative transfer model. Our best estimate of the annual BC snow albedo forcing in the Plateau is 2.9 W m-2 (uncertainty: 1.5–5.0 W m-226 ). We find that BC-snow internal mixing increases the albedo forcing by 40-60% compared with external mixing and coated BC increases the forcing by 30-50% compared with uncoated BC, whereas Koch snowflakes reduce the forcing by 20-40% relative to spherical snow grains. Our best estimate of the annual BC DRF at the top of the atmosphere is 2.3 W m-2 (uncertainty: 0.7–4.3 W m-230 ) in the Plateau after scaling the modeled BC absorption optical depth to Aerosol Robotic Network (AERONET) observations. The BC forcings are attributed to emissions from different regions.

  10. International Tests and the U.S. Educational Reforms: Can Success Be Replicated?

    ERIC Educational Resources Information Center

    Turgut, Guliz

    2013-01-01

    The ranking of the United States in major international tests such as the Progress in International Reading Literacy Study (PIRLS), Trends in International Mathematics and Science Study (TIMSS), and Program for International Student Assessment (PISA) is used as the driving force and rationale for the current educational reforms in the United…

  11. Internal Wave Apparatus for Copepod Behavior Assays

    NASA Astrophysics Data System (ADS)

    Jung, S.; Haas, K. A.; Webster, D. R.

    2015-11-01

    Internal waves are ubiquitous features in coastal marine environments and have been observed to mediate vertical distributions of zooplankton in situ. Internal waves are generated through oscillations of the pycnocline in stratified waters and thereby create fine-scale hydrodynamic cues that copepods and other zooplankton are known to sense, such as fluid density gradients and velocity gradients (quantified as shear deformation rate). The role of copepod behavior in response to cues associated with internal waves is largely unknown. Thus, a coupled quantification of copepod behavior and hydrodynamic cues will provide insight to the bio-physical interaction and the role of biological versus physical forcing in mediating organism distributions. We constructed a laboratory-scale internal wave apparatus to facilitate fine-scale observations of copepod behavior in flows that replicate in situ conditions of internal waves in a two-layer stratification. Three cases are chosen with density jump ranging between 0.75 - 1.5 kg/m3. Analytical analysis of the two-layer system provides guidance of the target forcing frequency to generate a standing internal wave with a single dominate frequency of oscillation. Flow visualization and signal processing of the interface location are used to quantify the wave characteristics. A copepod behavior assay is conducted, and sample trajectories are analyzed to identify copepod response to internal wave structure.

  12. A topaz international program overview

    SciTech Connect

    Thome, F.V.; Wyant, F.J.; McCarson, T.D. Jr.; Ponomarev-Stepnoi, N.N.

    1995-01-20

    Little did these visionaries know that the formation of the ``TOPAZ II Program,`` using former military space power technology of the Soviet Union, would become the preeminent example of technology cooperation between two former adversaries. A unique teaming arrangement formed in New Mexico, called the New Mexico Strategic Alliance and consisting of the Air Force Phillips Laboratory, Sandia National Laboratories, the University of New Mexico, and Los Alamos Nationalo Laboratory, was a key ingredient in making this program a success. A brief summary of some of the highlights of this technology partnership is given to explain how international patnerships of this type can enable commercialization and technology transfer.

  13. 26 CFR 20.2201-1 - Members of the Armed Forces dying during an induction period.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false Members of the Armed Forces dying during an... TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Miscellaneous § 20.2201-1 Members of the Armed Forces dying during an induction period. (a) The...

  14. PERSONAL EXPOSURE TO JP-8 JET FUEL VAPORS AND EXHAUST AT AIR FORCE BASES

    EPA Science Inventory

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and gro...

  15. Examining the Impact of External Influences on Police Use of Deadly Force over Time.

    ERIC Educational Resources Information Center

    White, Michael D.

    2002-01-01

    Used interrupted time-series analysis (ARIMA) to study the impact of legislation and judicial intervention on the use of deadly force by police officers in Philadelphia, Pennsylvania. Findings generally suggest that dynamic changes in the internal working environment can outweigh the influence of external mechanisms on deadly force use. Findings…

  16. International Agreement on Planetary Protection

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The maintenance of a NASA policy, is consistent with international agreements. The planetary protection policy management in OSS, with Field Center support. The advice from internal and external advisory groups (NRC, NAC/Planetary Protection Task Force). The technology research and standards development in bioload characterization. The technology research and development in bioload reduction/sterilization. This presentation focuses on: forward contamination - research on the potential for Earth life to exist on other bodies, improved strategies for planetary navigation and collision avoidance, and improved procedures for sterile spacecraft assembly, cleaning and/or sterilization; and backward contamination - development of sample transfer and container sealing technologies for Earth return, improvement in sample return landing target assessment and navigation strategy, planning for sample hazard determination requirements and procedures, safety certification, (liaison to NEO Program Office for compositional data on small bodies), facility planning for sample recovery system, quarantine, and long-term curation of 4 returned samples.

  17. Processes of Internal and International Migration from Chitwan, Nepal

    PubMed Central

    Bohra, Pratikshya; Massey, Douglas S.

    2011-01-01

    In this study we examine which factors predict internal and international migration from Chitwan, a flat valley located in the South-Central region of Nepal, seeking to measure the effect of theoretically specified variables such as human capital, social capital, physical capital, and neighborhood socioeconomic conditions while controlling for demographic variables. We use data from the Chitwan Valley Family Study (CVFS) to estimate a series of discrete time event history models of first and repeat migration to three competing destinations: other locations within Chitwan, other districts within Nepal, and places outside of Nepal. Results support hypotheses derived from neoclassical economics, the theory of new economics of migration, social capital theory, and cumulative causation theory. Our results underscore the need for a synthetic theoretical model that incorporates factors operating at the individual, household, and community levels. The use of multiple explanatory models yields a clearer picture of the forces driving internal and international migration from rural districts in developing nations such as Nepal. PMID:21423821

  18. Force reconstruction from tapping mode force microscopy experiments

    NASA Astrophysics Data System (ADS)

    Payam, Amir F.; Martin-Jimenez, Daniel; Garcia, Ricardo

    2015-05-01

    Fast, accurate, and robust nanomechanical measurements are intensely studied in materials science, applied physics, and molecular biology. Amplitude modulation force microscopy (tapping mode) is the most established nanoscale characterization technique of surfaces for air and liquid environments. However, its quantitative capabilities lag behind its high spatial resolution and robustness. We develop a general method to transform the observables into quantitative force measurements. The force reconstruction algorithm has been deduced on the assumption that the observables (amplitude and phase shift) are slowly varying functions of the tip-surface separation. The accuracy and applicability of the method is validated by numerical simulations and experiments. The method is valid for liquid and air environments, small and large free amplitudes, compliant and rigid materials, and conservative and non-conservative forces.

  19. Van der Waals Forces in Magnetic Resonance Force Microscopy

    NASA Astrophysics Data System (ADS)

    MacBeth, Melissa; Garbini, Joseph; Sidles, John; Dougherty, William; Chao, Shih-Hui

    2001-03-01

    Magnetic Resonance Force Microscopy detects modulated spin-gradient forces by means of a soft, high phQ cantilever. When the magnetic tip of the cantilever is brought close to the sample surface, static forces significantly change the net restoring force, altering the cantilever mechanical resonance frequency. This frequency shift can be very large compared to the width of the cantilever resonance. As previously demonstrated, active feedback control of the cantilever motion greatly improves cantilever dynamics. The control algorithm is obtained by formal optimal control techniques and implemented with a digital signal processor (DSP). We have recently enabled the DSP to continuously evaluate the frequency of the cantilever as the tip approaches the sample and seamlessly adapt control parameters for optimized performance. Tip-sample approach under adaptive control can avoid snap-in and obtain much smaller separations than uncontrolled approach, and the static potential is reliably characterized.

  20. Point-Force Energy Coupling

    NASA Astrophysics Data System (ADS)

    Burton, Tristan; Squires, Kyle

    2005-11-01

    Fully resolved simulations of particle-laden turbulent flows are computationally expensive even with a single particle. Therefore, simulations of flows with realistic numbers of particles typically treat the disperse phase as point-particles and models are used to account for the interaction between the phases. The particle trajectories are determined using a Lagrangian particle equation of motion that accounts for the fluid forces. The effect of the particulate phase on the fluid is included using point-force momentum coupling, where the opposite of the force applied to each particle by the fluid is distributed back to fluid grid points in a local region. In this work, we perform direct numerical simulation (DNS) of a particle moving at a prescribed constant or time-dependent velocity through a stationary fluid, and use the resulting force history in a corresponding point-force simulation to study point-force energy coupling. The energy input from the moving particle and the fluid dissipation in the DNS are compared to corresponding quantities in the unresolved calculation. A range of particle Reynolds numbers and ratios of the particle diameter to the unresolved grid spacing are considered to determine the conditions under which point-force momentum coupling provides accurate energy coupling.

  1. Electrostatic forces in planetary rings

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.; Shan, Linhua; Havnes, O.

    1988-01-01

    The average charge on a particle in a particle-plasma cloud, the plasma potential inside the cloud, and the Coulomb force acting on the particle are calculated. The net repulsive electrostatic force on a particle depends on the plasma density, temperature, density of particles, particle size, and the gradient of the particle density. In a uniformly dense ring the electrostatic repulsion is zero. It is also shown that the electrostatic force acts like a pressure force, that even a collisionless ring can be stable against gravitational collapse, and that a finite ring thickness does not necessarily imply a finite velocity dispersion. A simple criterion for the importance of electrostatic forces in planetary rings is derived which involves the calculation of the vertical ring thickness which would result if only electrostatic repulsion were responsible for the finite ring thickness. Electrostatic forces are entirely negligible in the main rings of Saturn and the E and G rings. They may also be negligible in the F ring. However, the Uranian rings and Jupiter's ring seem to be very much influenced by electrostatic repulsion. In fact, electrostatic forces could support a Jovian ring which is an order of magnitude more dense than observed.

  2. Climate forcing by anthropogenic aerosols.

    PubMed

    Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J

    1992-01-24

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes. PMID:17842894

  3. Climate forcing by anthropogenic aerosols

    NASA Technical Reports Server (NTRS)

    Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

    1992-01-01

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol, in particular, has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

  4. Imprints of climate forcings in global gridded temperature data

    NASA Astrophysics Data System (ADS)

    Mikšovský, J.; Holtanová, E.; Pišoft, P.

    2015-11-01

    Monthly near-surface temperature anomalies from several gridded datasets (GISTEMP, Berkeley Earth, MLOST, HadCRUT4, 20th Century Reanalysis) were investigated and compared with regard to the presence of components attributable to external climate forcings (anthropogenic, solar and volcanic) and to major internal climate variability modes (El Niño/Southern Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation and variability characterized by the Trans-Polar Index). Multiple linear regression was used to separate components related to individual explanatory variables in local monthly temperatures as well as in their global means, over the 1901-2010 period. Strong correlations of temperature and anthropogenic forcing were confirmed for most of the globe, whereas only weaker and mostly statistically insignificant connections to solar activity were indicated. Imprints of volcanic forcing were found to be largely insignificant in the local temperatures, in contrast to the clear volcanic signature in their global averages. An attention was also paid to the manifestations of short-term time shifts in the responses to the forcings, and to differences in the spatial fingerprints detected from individual temperature datasets: it is shown that although the resemblance of the response patterns is usually strong, some regional contrasts appear. Noteworthy differences from the other datasets were found especially for the 20th Century Reanalysis, particularly for the components attributable to anthropogenic and volcanic forcing over land, but also in some of the teleconnection patterns related to the internal variability modes.

  5. Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse

    NASA Astrophysics Data System (ADS)

    Bond, T. C.; Zarzycki, C.; Flanner, M. G.; Koch, D. M.

    2010-06-01

    We propose a measure to quantify climate warming or cooling by pollutants with atmospheric lifetimes of less than one year: the Specific Forcing Pulse (SFP). SFP is the amount of energy added to the Earth system per mass of pollutant emitted. Global average SFP for black carbon, including atmosphere and cryosphere, is 1.12 GJ g-1 and that for organic matter is -0.061 GJ g-1. We provide regional values for black carbon (BC) and organic matter (OM) emitted from 23 source-region combinations, divided between atmosphere and cryosphere impacts and identifying forcing by latitude. Regional SFP varies by about 40% for black carbon. This variation is relatively small because of compensating effects; particles from regions that affect ice albedo typically have shorter atmospheric lifetimes because of lower convection. The ratio between BC and OM SFP implies that, for direct forcing, an OM:BC mass ratio of 15 has a neutral effect on top-of-atmosphere direct forcing for any region, and any lower ratio induces direct warming. However, important processes, particularly cloud changes that tend toward cooling, have not been included here. We demonstrate ensemble adjustment, in which we produce a "best estimate" by combining a suite of diverse but simple models and enhanced models of greater complexity. Adjustments for black carbon internal mixing and for regional variability are discussed; regions with convection are implicated in greater model diversity. SFP expresses scientific uncertainty and separates it from policy uncertainty; the latter is caused by disagreements about the relevant time horizon, impact, or spatial scale of interest. However, metrics used in policy discussions, such as global warming potentials, are easily derived from SFP. Global-average SFP for biofuel and fossil fuel emissions translates to a 100-year GWP of about 760 for black carbon and -40 for organic matter when snow forcing is included. Ensemble-adjusted estimates of atmospheric radiative impact by

  6. Population commission discusses international migration.

    PubMed

    1997-01-01

    At the 30th session of the Commission on Population and Development during February 24-28, 1997, international migration was the main topic, with special linkages between migration and development and on gender issues and the family. New and emerging issues were also considered. Members stressed the need for more reliable data on migration, the direction of migrants flows, and the characteristics of migrants. The Commission requested a task force on basic social services to hold a technical symposium of experts on international migration in 1998. Its chair, Dr. Nafis Sadik, said that migration issues should based on the reality of choice not on coercive measures or quotas. Almost half of the migrants globally are women. The Commission was given a new impetus by the International Conference on Population and Development held at Cairo in 1994. Migration pressures intensified in the second half of the 1980s and in the early 1990s, creating areas of concern: the negative impact of short-term migration on working conditions in host countries; migration pressures emanating from climatic change; the protection of migrant women and their children; the right of receiving countries to regulate access to their territory; the adverse consequences of forced migration; the situation of persons whose asylum claims have been rejected; the trafficking in women and children, prostitution and coercive adoption; and the sudden and massive arrival of refugees in need of international protection. The 1998 session of the Commission will feature the theme of health and mortality, with special emphasis on the linkages between health and development and on gender and age. PMID:12292475

  7. Community College Internal Auditors: Internal Audit Guidebook.

    ERIC Educational Resources Information Center

    Jones, Ronna; And Others

    This guidebook includes information compiled by the "Audit Manual" committee of Community College Internal Auditors (CCIA) from several California community college districts regarding their internal auditing practices. The first section of the guidebook discusses the purpose of internal audits, indicating that audits assist members of the…

  8. Casimir force between liquid metals

    NASA Astrophysics Data System (ADS)

    Esquivel-Sirvent, R.; Escobar, J. V.

    2014-08-01

    We present a theoretical calculation of the Casimir force between liquid metals at room temperature using as case studies mercury (Hg) and eutectic indium gallium (EInGa). The surface tension of the liquids creates surfaces of zero roughness that are truly equipotential, an ideal characteristic for Casimir force experiments. As we show the dielectric properties of Au, EInGa and Hg are very similar and the difference on the Casimir force between Au and EInGa and Au and Hg is less than 4%. Based on these results, a modification of the IUPUI experiment for detecting deviations of Newtonian gravity is proposed.

  9. Nuclear forces and chiral theories

    SciTech Connect

    Friar, J.L. |

    1995-09-01

    Recent successes in ab initio calculations of light nuclei (A=2-6) will be reviewed and correlated with the dynamical consequences of chiral symmetry. The tractability of nuclear physics evinced by these results is evidence for that symmetry. The relative importance of three-nucleon forces, four-nucleon forces, multi-pion exchanges, and relativistic corrections will be discussed in the context of effective field theories and dimensional power counting. Isospin violation in the nuclear force will also be discussed in this context.

  10. Calibration of frictional forces in atomic force microscopy

    SciTech Connect

    Ogletree, D.F.; Carpick, R.W.; Salmeron, M.

    1996-09-01

    The atomic force microscope can provide information on the atomic-level frictional properties of surfaces, but reproducible quantitative measurements are difficult to obtain. Parameters that are either unknown or difficult to precisely measure include the normal and lateral cantilever force constants (particularly with microfabricated cantilevers), the tip height, the deflection sensor response, and the tip structure and composition at the tip-surface contact. We present an {ital in} {ital situ} experimental procedure to determine the response of a cantilever to lateral forces in terms of its normal force response. This procedure is quite general. It will work with any type of deflection sensor and does not require the knowledge or direct measurement of the lever dimensions or the tip height. In addition, the shape of the tip apex can be determined. We also discuss a number of specific issues related to force and friction measurements using optical lever deflection sensing. We present experimental results on the lateral force response of commercially available V-shaped cantilevers. Our results are consistent with estimates of lever mechanical properties using continuum elasticity theory. {copyright} {ital 1996 American Institute of Physics.}

  11. Risk assessment in international operations

    SciTech Connect

    Stricklin, Daniela L.

    2008-11-15

    During international peace-keeping missions, a diverse number of non-battle hazards may be encountered, which range from heavily polluted areas, endemic disease, toxic industrial materials, local violence, traffic, and even psychological factors. Hence, elevated risk levels from a variety of sources are encountered during deployments. With the emphasis within the Swedish military moving from national defense towards prioritization of international missions in atypical environments, the risk of health consequences, including long term health effects, has received greater consideration. The Swedish military is interested in designing an optimal approach for assessment of health threats during deployments. The Medical Intelligence group at FOI CBRN Security and Defence in Umea has, on request from and in collaboration with the Swedish Armed Forces, reviewed a variety of international health threat and risk assessment models for military operations. Application of risk assessment methods used in different phases of military operations will be reviewed. An overview of different international approaches used in operational risk management (ORM) will be presented as well as a discussion of the specific needs and constraints for health risk assessment in military operations. This work highlights the specific challenges of risk assessment that are unique to the deployment setting such as the assessment of exposures to a variety of diverse hazards concurrently.

  12. Risk assessment in international operations.

    PubMed

    Stricklin, Daniela L

    2008-11-15

    During international peace-keeping missions, a diverse number of non-battle hazards may be encountered, which range from heavily polluted areas, endemic disease, toxic industrial materials, local violence, traffic, and even psychological factors. Hence, elevated risk levels from a variety of sources are encountered during deployments. With the emphasis within the Swedish military moving from national defense towards prioritization of international missions in atypical environments, the risk of health consequences, including long term health effects, has received greater consideration. The Swedish military is interested in designing an optimal approach for assessment of health threats during deployments. The Medical Intelligence group at FOI CBRN Security and Defence in Umeå has, on request from and in collaboration with the Swedish Armed Forces, reviewed a variety of international health threat and risk assessment models for military operations. Application of risk assessment methods used in different phases of military operations will be reviewed. An overview of different international approaches used in operational risk management (ORM) will be presented as well as a discussion of the specific needs and constraints for health risk assessment in military operations. This work highlights the specific challenges of risk assessment that are unique to the deployment setting such as the assessment of exposures to a variety of diverse hazards concurrently. PMID:18325560

  13. Visualization of Force Fields in Protein Structure Prediction

    SciTech Connect

    Crawford, Clark; Kreylos, Oliver; Hamann, Bernd; Crivelli, Silvia

    2005-04-26

    The force fields used in molecular computational biology are not mathematically defined in such a way that their mathematical representation would facilitate the straightforward application of volume visualization techniques. To visualize energy, it is necessary to define a spatial mapping for these fields. Equipped with such a mapping, we can generate volume renderings of the internal energy states in a molecule. We describe our force field, the spatial mapping that we used for energy, and the visualizations that we produced from this mapping. We provide images and animations that offer insight into the computational behavior of the energy optimization algorithms that we employ.

  14. Flagellar force production during regeneration in Chlamydomonas reinhardtii

    NASA Astrophysics Data System (ADS)

    Yukich, John N.; Clodfelter, Catherine; Bernd, Karen K.

    2009-11-01

    Several respiratory, digestive, and reproductive disorders originate with motional dysfunction of cilia and flagella. The usefulness of cilia and flagella is understood, but the internal mechanism for creating their breast stroke-like motion is not. This study reports on standardization of calibration, trapping and cell movement recording methods. Our techniques permit us to measure the flagellar swimming force of Chlamydomonas during flagella regeneration. We find that as flagella length increases, the flagellar force is maximized after 50% of full length is achieved except for a significant dip at 75% of full length. These results raise many questions regarding the flagella infrastructure.

  15. Calibration Designs for Non-Monolithic Wind Tunnel Force Balances

    NASA Technical Reports Server (NTRS)

    Johnson, Thomas H.; Parker, Peter A.; Landman, Drew

    2010-01-01

    This research paper investigates current experimental designs and regression models for calibrating internal wind tunnel force balances of non-monolithic design. Such calibration methods are necessary for this class of balance because it has an electrical response that is dependent upon the sign of the applied forces and moments. This dependency gives rise to discontinuities in the response surfaces that are not easily modeled using traditional response surface methodologies. An analysis of current recommended calibration models is shown to lead to correlated response model terms. Alternative modeling methods are explored which feature orthogonal or near-orthogonal terms.

  16. History force on coated microbubbles propelled by ultrasound

    NASA Astrophysics Data System (ADS)

    Garbin, Valeria; Dollet, Benjamin; Overvelde, Marlies; Cojoc, Dan; Di Fabrizio, Enzo; van Wijngaarden, Leen; Prosperetti, Andrea; de Jong, Nico; Lohse, Detlef; Versluis, Michel

    2009-09-01

    In this paper the unsteady translation of coated microbubbles propelled by acoustic radiation force is studied experimentally. A system of two pulsating microbubbles of the type used as contrast agent in ultrasound medical imaging is considered, which attract each other as a result of the secondary Bjerknes force. Optical tweezers are used to isolate the bubble pair from neighboring boundaries so that it can be regarded as if in an unbounded fluid and the hydrodynamic forces acting on the system can be identified unambiguously. The radial and translational dynamics, excited by a 2.25 MHz ultrasound wave, is recorded with an ultrahigh speed camera at 15×106 frames/s. The time-resolved measurements reveal a quasisteady component of the translational velocity, at an average translational Reynolds number ⟨Ret⟩≈0.5, and an oscillatory component at the same frequency as the radial pulsations, as predicted by existing models. Since the coating enforces a no-slip boundary condition, an increased viscous dissipation is expected due to the oscillatory component, similar to the case of an oscillating rigid sphere that was first described by Stokes ["On the effect of the internal friction of fluids on the motion of pendulums," Trans. Cambridge Philos. Soc. 9, 8 (1851)]. A history force term is therefore included in the force balance, in the form originally proposed by Basset and extended to the case of time-dependent radius by Takemura and Magnaudet ["The history force on a rapidly shrinking bubble rising at finite Reynolds number," Phys. Fluids 16, 3247 (2004)]. The instantaneous values of the hydrodynamic forces extracted from the experimental data confirm that the history force accounts for the largest part of the viscous force. The trajectories of the bubbles predicted by numerically solving the equations of motion are in very good agreement with the experiment.

  17. International Education Hubs: Collaboration for Competitiveness and Sustainability

    ERIC Educational Resources Information Center

    Knight, Jane

    2014-01-01

    This chapter focuses on the development of education hubs, a recent phenomenon in international higher education. Three models of hubs are examined in relation to the forces, risks, and opportunities of globalization and how local and international collaborations are essential for both global competitiveness and sustainability.

  18. DOD Service Academies. Status Report on Reviews of Student Treatment. Statement of Paul L. Jones, Director, Defense Force Management Issues, National Security and International Affairs Division. Testimony before the Subcommittee on Manpower and Personnel, Committee on Armed Services, U.S. Senate.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. National Security and International Affairs Div.

    Preliminary results of ongoing reviews of student treatment at the U.S. Military Academy, the U.S. Naval Academy, and the U.S. Air Force Academy show the following: (1) hazing has not completely disappeared from the academies, despite prohibitions against it; (2) women and minorities have not reached the same level of achievement as white males in…

  19. Report of the Fermilab ILC Citizens' Task Force

    SciTech Connect

    2008-06-01

    Fermi National Accelerator Laboratory convened the ILC Citizens' Task Force to provide guidance and advice to the laboratory to ensure that community concerns and ideas are included in all public aspects of planning and design for a proposed future accelerator, the International Linear Collider. In this report, the members of the Task Force describe the process they used to gather and analyze information on all aspects of the proposed accelerator and its potential location at Fermilab in northern Illinois. They present the conclusions and recommendations they reached as a result of the learning process and their subsequent discussions and deliberations. While the Task Force was charged to provide guidance on the ILC, it became clear during the process that the high cost of the proposed accelerator made a near-term start for the project at Fermilab unlikely. Nevertheless, based on a year of extensive learning and dialogue, the Task Force developed a series of recommendations for Fermilab to consider as the laboratory develops all successor projects to the Tevatron. The Task Force recognizes that bringing a next-generation particle physics project to Fermilab will require both a large international effort and the support of the local community. While the Task Force developed its recommendations in response to the parameters of a future ILC, the principles they set forth apply directly to any large project that may be conceived at Fermilab, or at other laboratories, in the future. With this report, the Task Force fulfills its task of guiding Fermilab from the perspective of the local community on how to move forward with a large-scale project while building positive relationships with surrounding communities. The report summarizes the benefits, concerns and potential impacts of bringing a large-scale scientific project to northern Illinois.

  20. Globalization and the Growth of International Educational Testing and National Assessment

    ERIC Educational Resources Information Center

    Kamens, David H.; McNeely, Connie L.

    2010-01-01

    In this article, the authors develop an argument about the global forces that have led to the explosive growth of national educational assessment and international testing. In particular, the authors argue that the international acceptance of testing comes from key ideological forces in the world polity that are associated with the accelerating…

  1. Dissipative Forces and Quantum Mechanics

    ERIC Educational Resources Information Center

    Eck, John S.; Thompson, W. J.

    1977-01-01

    Shows how to include the dissipative forces of classical mechanics in quantum mechanics by the use of non-Hermetian Hamiltonians. The Ehrenfest theorem for such Hamiltonians is derived, and simple examples which show the classical correspondences are given. (MLH)

  2. Teleoperation with virtual force feedback

    SciTech Connect

    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.

  3. Active media under rotational forcing.

    PubMed

    Pérez-Villar, Vicente; Porteiro, Jose L F; Muñuzuri, Alberto P

    2006-10-01

    The bubble-free Belousov-Zhabotinsky reaction has been used to study the effects of centrifugal forces on autowave propagation. The reaction parameters were chosen such that the system oscillates naturally creating target waves. In the present study, the system was forced to rotate with a constant velocity around a central axis. In studying the effects of such a forcing on the system, we focused on target dynamics. The system reacts to this forcing in different ways, the most spectacular being a dramatic increase in the period of the target, the effect growing stronger as we move away from the center of rotation. A numerical study was carried out using the two-variable Oregonator model, modified to include convective effects through the diffusion coefficient. The numerical results showed a good qualitative agreement with those of the experiments. PMID:17155149

  4. Calibration of lateral force measurements in atomic force microscopy with a piezoresistive force sensor

    SciTech Connect

    Xie Hui; Vitard, Julien; Haliyo, Sinan; Regnier, Stephane

    2008-03-15

    We present here a method to calibrate the lateral force in the atomic force microscope. This method makes use of an accurately calibrated force sensor composed of a tipless piezoresistive cantilever and corresponding signal amplifying and processing electronics. Two ways of force loading with different loading points were compared by scanning the top and side edges of the piezoresistive cantilever. Conversion factors between the lateral force and photodiode signal using three types of atomic force microscope cantilevers with rectangular geometries (normal spring constants from 0.092 to 1.24 N/m and lateral stiffness from 10.34 to 101.06 N/m) were measured in experiments using the proposed method. When used properly, this method calibrates the conversion factors that are accurate to {+-}12.4% or better. This standard has less error than the commonly used method based on the cantilever's beam mechanics. Methods such of this allow accurate and direct conversion between lateral forces and photodiode signals without any knowledge of the cantilevers and the laser measuring system.

  5. Forced motion near black holes

    SciTech Connect

    Gair, Jonathan R.; Flanagan, Eanna E.; Drasco, Steve; Hinderer, Tanja; Babak, Stanislav

    2011-02-15

    We present two methods for integrating forced geodesic equations in the Kerr spacetime. The methods can accommodate arbitrary forces. As a test case, we compute inspirals caused by a simple drag force, mimicking motion in the presence of gas. We verify that both methods give the same results for this simple force. We find that drag generally causes eccentricity to increase throughout the inspiral. This is a relativistic effect qualitatively opposite to what is seen in gravitational-radiation-driven inspirals, and similar to what others have observed in hydrodynamic simulations of gaseous binaries. We provide an analytic explanation by deriving the leading order relativistic correction to the Newtonian dynamics. If observed, an increasing eccentricity would thus provide clear evidence that the inspiral was occurring in a nonvacuum environment. Our two methods are especially useful for evolving orbits in the adiabatic regime. Both use the method of osculating orbits, in which each point on the orbit is characterized by the parameters of the geodesic with the same instantaneous position and velocity. Both methods describe the orbit in terms of the geodesic energy, axial angular momentum, Carter constant, azimuthal phase, and two angular variables that increase monotonically and are relativistic generalizations of the eccentric anomaly. The two methods differ in their treatment of the orbital phases and the representation of the force. In the first method, the geodesic phase and phase constant are evolved together as a single orbital phase parameter, and the force is expressed in terms of its components on the Kinnersley orthonormal tetrad. In the second method, the phase constants of the geodesic motion are evolved separately and the force is expressed in terms of its Boyer-Lindquist components. This second approach is a direct generalization of earlier work by Pound and Poisson [A. Pound and E. Poisson, Phys. Rev. D 77, 044013 (2008).] for planar forces in a

  6. COOLING FORCE MEASUREMENTS IN CELSIUS.

    SciTech Connect

    GALNANDER, B.; FEDOTOV, A.V.; LITVINENKO, V.N.; ET AL.

    2005-09-18

    The design of future high energy coolers relies heavily on extending the results of cooling force measurements into new regimes by using simulation codes. In order to carefully benchmark these codes we have accurately measured the longitudinal friction force in CELSIUS by recording the phase shift between the beam and the RF voltage while varying the RF frequency. Moreover, parameter dependencies on the electron current, solenoid magnetic field and magnetic field alignment were carried out.

  7. Cooling Force Measurements at CELSIUS

    SciTech Connect

    Ga ring lnander, B.; Lofnes, T.; Ziemann, V.; Fedotov, A. V.; Litvinenko, V. N.; Sidorin, A. O.; Smirnov, A. V.

    2006-03-20

    The design of future high energy coolers relies heavily on extending the results of cooling force measurements into new regimes by using simulation codes. In order to carefully benchmark these codes we have accurately measured the longitudinal friction force in CELSIUS by recording the phase shift between the beam and the RF voltage while varying the RF frequency. Moreover, parameter dependencies on the electron current, solenoid magnetic field and magnetic field alignment were carried out.

  8. Electrostatic forces for personnel restraints

    NASA Technical Reports Server (NTRS)

    Ashby, N.; Ciciora, J.; Gardner, R.; Porter, K.

    1977-01-01

    The feasibility of utilizing electrostatic forces for personnel retention devices on exterior spacecraft surfaces was analyzed. The investigation covered: (1) determination of the state of the art; (2) analysis of potential adhesion surfaces; (3) safety considerations for personnel; (4) electromagnetic force field determination and its effect on spacecraft instrumentation; and (5) proposed advances to current technology based on documentation review, analyses, and experimental test data.

  9. Finger Forces in Clarinet Playing

    PubMed Central

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low–high; tempo: slow–fast, dynamics: soft–loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low–high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean) and peak force (Fmax) were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N). Such sensor instruments provide useful insights into player

  10. Clinical Application of the Forced Oscillation Technique.

    PubMed

    Shirai, Toshihiro; Kurosawa, Hajime

    2016-01-01

    The forced oscillation technique (FOT) is a noninvasive method with which to measure respiratory system resistance and reactance during tidal breathing. Recently, its clinical application has spread worldwide with the expansion of commercially available broadband frequency FOT devices, including MostGraph and Impulse Oscillometry. An increasing number of reports have supported the usefulness of the FOT in the management of asthma and chronic obstructive pulmonary disease (COPD). However, the FOT is not a surrogate test for spirometry, but should be used complementarily. Furthermore, reference values are not necessarily available and the interpretation of some measured data is controversial. There is a need to update the international statement for not only technical aspects but also the clinical use of the FOT. In this review, we summarize the previously published studies and discuss how to use the FOT in a clinical setting. PMID:26984069

  11. Vision-based force measurement.

    PubMed

    Greminger, Michael A; Nelson, Bradley J

    2004-03-01

    This paper demonstrates a method to visually measure the force distribution applied to a linearly elastic object using the contour data in an image. The force measurement is accomplished by making use of the result from linear elasticity that the displacement field of the contour of a linearly elastic object is sufficient to completely recover the force distribution applied to the object. This result leads naturally to a deformable template matching approach where the template is deformed according to the governing equations of linear elasticity. An energy minimization method is used to match the template to the contour data in the image. This technique of visually measuring forces we refer to as vision-based force measurement (VBFM). VBFM has the potential to increase the robustness and reliability of micromanipulation and biomanipulation tasks where force sensing is essential for success. The effectiveness of VBFM is demonstrated for both a microcantilever beam and a microgripper. A sensor resolution of less than +/- 3 nN for the microcantilever and +/- 3 mN for the microgripper was achieved using VBFM. Performance optimizations for the energy minimization problem are also discussed that make this algorithm feasible for real-time applications. PMID:15376877

  12. Elastodynamic image forces on dislocations

    PubMed Central

    Gurrutxaga-Lerma, Beñat; Balint, Daniel S.; Dini, Daniele; Sutton, Adrian P.

    2015-01-01

    The elastodynamic image forces on edge and screw dislocations in the presence of a planar-free surface are derived. The explicit form of the elastodynamic fields of an injected, quiescent screw dislocation are also derived. The resulting image forces are affected by retardation effects: the dislocations experience no image force for a period of time defined by the arrival and reflection at the free surface of the dislocation fields. For the case of injected, stationary dislocations, it is shown that the elastodynamic image force tends asymptotically to the elastotatic prediction. For the case of injected, moving dislocations, it is shown that the elastodynamic image force on both the edge and the screw dislocations is magnified by inertial effects, and becomes increasingly divergent with time; this additional effect, missing in the elastostatic description, is shown to be substantial even for slow moving dislocations. Finally, it is shown that the elastodynamic image force of an edge dislocation moving towards the surface at the Rayleigh wave speed becomes repulsive, rather than attractive; this is suggestive of instabilities at the core of the dislocation, and likely resonances with the free surface. PMID:26528080

  13. Photoinduced magnetic force between nanostructures

    NASA Astrophysics Data System (ADS)

    Guclu, Caner; Tamma, Venkata Ananth; Wickramasinghe, Hemantha Kumar; Capolino, Filippo

    2015-12-01

    Photoinduced magnetic force between nanostructures, at optical frequencies, is investigated theoretically. Till now optical magnetic effects were not used in scanning probe microscopy because of the vanishing natural magnetism with increasing frequency. On the other hand, artificial magnetism in engineered nanostructures led to the development of measurable optical magnetism. Here two examples of nanoprobes that are able to generate strong magnetic dipolar fields at optical frequency are investigated: first, an ideal magnetically polarizable nanosphere and then a circular cluster of silver nanospheres that has a looplike collective plasmonic resonance equivalent to a magnetic dipole. Magnetic forces are evaluated based on nanostructure polarizabilities, i.e., induced magnetic dipoles, and magnetic-near field evaluations. As an initial assessment on the possibility of a magnetic nanoprobe to detect magnetic forces, we consider two identical magnetically polarizable nanoprobes and observe magnetic forces on the order of piconewtons, thereby bringing it within detection limits of conventional atomic force microscopes at ambient pressure and temperature. The detection of magnetic force is a promising method in studying optical magnetic transitions that can be the basis of innovative spectroscopy applications.

  14. Space station task force perspective

    NASA Technical Reports Server (NTRS)

    Hicks, C.

    1984-01-01

    Space station planning quidelines; architecture; functions; preliminary mission data base; scope for international and commercial participation; schedules; servicing capability; technology development; and space station program interfaces are discussed.

  15. 32 CFR 632.4 - Deadly force.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a...

  16. 32 CFR 632.4 - Deadly force.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a...

  17. 32 CFR 632.4 - Deadly force.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a...

  18. 32 CFR 632.4 - Deadly force.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a...

  19. 32 CFR 632.4 - Deadly force.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Deadly force. 632.4 Section 632.4 National... INVESTIGATIONS USE OF FORCE BY PERSONNEL ENGAGED IN LAW ENFORCEMENT AND SECURITY DUTIES § 632.4 Deadly force. (a) Deadly force is destructive physical force directed against a person or persons (e.g., firing a...

  20. Experimental Investigation of Forces Produced by Misaligned Steel Rollers

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

    2010-01-01

    The International Space Station (ISS) Solar Alpha Rotary Joint (SARJ) uses a roller-based mechanism for positioning of the solar arrays. The forces and moments that develop at the roller interfaces are influenced by the design including the kinematic constraints and the lubrication condition. To help understand the SARJ operation, a set of dedicated experiments were completed using roller pairs. Of primary interest was to measure the axial force directed along the axis of rotation of the roller as a function of shaft misalignment. The conditions studied included dry and clean surfaces; one surface plated by a gold film, and greased surfaces. For the case of a bare 440C roller against a nitrided 15-5 roller without lubrication, the axial force can be as great as 0.4 times the normal load for a shaft angle of 0.5 deg. Such a magnitude of force on a roller in the SARJ mechanism would cause roller tipping and contact pressures much greater than anticipated by the designers. For the case of a bare 440C roller against a nitrided 15-5 roller with grease lubrication, the axial force does not exceed about 0.15 times the normal load even for the largest misalignment angles tested. Gold films provided good lubrication for the short duration testing reported herein. Grease lubrication limited the magnitude of the axial force to even smaller magnitudes than was achieved with the gold films. The experiments demonstrate the critical role of good lubrication for the SARJ mechanism.

  1. Experimental Investigation of Forces Produced by Misaligned Steel Rollers

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

    2010-01-01

    The International Space Station Solar Alpha Rotary Joint (SARJ) uses a roller-based mechanism for positioning of the solar arrays. The forces and moments that develop at the roller interfaces are influenced by the design including the kinematic constraints and the lubrication condition. To help understand the SARJ operation, a set of dedicated experiments were completed using roller pairs. Of primary interest was to measure the axial force directed along the axis of rotation of the roller as a function of shaft misalignment. The conditions studied included dry and clean surfaces; one surface plated by a gold film, and greased surfaces. For the case of a bare 440C roller against a nitrided 15-5 roller without lubrication, the axial force can be as great as 0.4 times the normal load for a shaft angle of 0.5 degree. Such a magnitude of force on a roller in the SARJ mechanism would cause roller tipping and contact pressures much greater than anticipated by the designers. For the case of a bare 440C roller against a nitrided 15-5 roller with grease lubrication, the axial force does not exceed about 0.15 times the normal load even for the largest misalignment angles tested. Gold films provided good lubrication for the short duration testing reported herein. Grease lubrication limited the magnitude of the axial force to even smaller magnitudes than was achieved with the gold films. The experiments demonstrate the critical role of good lubrication for the SARJ mechanism.

  2. Motion and force control of multiple robotic manipulators

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Kreutz-Delgado, Kenneth

    1992-01-01

    This paper addresses the motion and force control problem of multiple robot arms manipulating a cooperatively held object. A general control paradigm is introduced which decouples the motion and force control problems. For motion control, different control strategies are constructed based on the variables used as the control input in the controller design. There are three natural choices; acceleration of a generalized coordinate, arm tip force vectors, and the joint torques. The first two choices require full model information but produce simple models for the control design problem. The last choice results in a class of relatively model independent control laws by exploiting the Hamiltonian structure of the open loop system. The motion control only determines the joint torque to within a manifold, due to the multiple-arm kinematic constraint. To resolve the nonuniqueness of the joint torques, two methods are introduced. If the arm and object models are available, an optimization can be performed to best allocate the desired and effector control force to the joint actuators. The other possibility is to control the internal force about some set point. It is shown that effective force regulation can be achieved even if little model information is available.

  3. How Predictive Is Grip Force Control in the Complete Absence of Somatosensory Feedback?

    ERIC Educational Resources Information Center

    Nowak, Dennis A.; Glasauer, Stefan; Hermsdorfer, Joachim

    2004-01-01

    Grip force control relies on accurate internal models of the dynamics of our motor system and the external objects we manipulate. Internal models are not fixed entities, but rather are trained and updated by sensory experience. Sensory feedback signals relevant object properties and mechanical events, e.g. at the skin-object interface, to modify…

  4. Are Mathematics and Science Test Scores Good Indicators of Labor-Force Quality?

    ERIC Educational Resources Information Center

    Chen, Shiu-Sheng; Luoh, Ming-Ching

    2010-01-01

    Using data from the Programme for International Student Assessment (PISA) and the Trends in International Mathematics and Science Study (TIMSS), we investigate the link between test scores (mathematics and science) and cross-country income differences. We would like to know whether test scores are good indicators of labor-force quality. The…

  5. The new science of sales force productivity.

    PubMed

    Ledingham, Dianne; Kovac, Mark; Simon, Heidi Locke

    2006-09-01

    For years, sales managers at many companies have relied on top performers and sheer numbers of sales reps to stay competitive. But while they may have squeaked by on this wing-and-a-prayer technique, their sales teams haven't thrived the way they once did. Today's most successful sales leaders are taking a more scientific approach. Savvy managers are reshaping their tactics in response to changing markets. They are reaching out to new customers in innovative ways. And they are increasing productivity by helping the reps they already have make the most of their skills and resources. Leaders who take a scientific approach to sales force effectiveness have learned to use four levers to boost their reps' productivity in a predictable and manageable way. First, they systematically target their firms' offerings, matching the right products with the right customers. Second, they optimize the automation, tools, and procedures at their disposal, providing reps with the support they need to boost sales.Third, they analyze and manage their reps' performance, measuring both internal processes and results to determine where their teams' strengths and weaknesses are. Fourth, they pay close attention to sales force deployment--how well sales, support, marketing, and delivery resources are matched to customers. These four levers can help sales leaders increase productivity across the board, the authors say, though they have the greatest impact on lower-ranked performers. The overall effect of increasing the average sales per employee can be exponential; it means a company won't have to rely on just a few talented individuals to stay competitive. This is especially important because finding and keeping star salespeople is more difficult than ever. What's more, managers who optimize the sales forces they already have can see returns they never thought possible. PMID:16967626

  6. Tension density as counter force to the Lorentz force density

    NASA Astrophysics Data System (ADS)

    Nozaki, Hiroo; Senami, Masato; Ichikawa, Kazuhide; Tachibana, Akitomo

    2016-08-01

    It is confirmed numerically that the tension density defined in quantum field theory is the counter force to the Lorentz force density. We take benzenedithiol in a nonequilibrium steady state as an example for the numerical demonstration of the balance between these densities. While we use simply a nonequilibrium Green’s function method for a quantum conduction state instead of computations based on quantum field theory, the balance between the tension density and the Lorentz force density can be confirmed. The tension density is free from the relaxation time ansatz and defined as a local quantity. The tension density may give a novel viewpoint to the understanding of the physics of electrical conduction.

  7. Force measurements in aerodynamics using piezoelectric multicomponent force transducers

    NASA Astrophysics Data System (ADS)

    Schewe, G.

    The present paper is concerned with a device for the measurement of steady and unsteady aerodynamic forces in a wind tunnel test. The paper represents a continuation of an article written by Schewe (1982) about a multicomponent balance consisting of piezoelectric force transducers for a high-pressure wind tunnel. Advantages of the piezoelectric force-measuring technique compared to other techniques are related to the high rigidity of the quartz crystal sensor elements, taking into account low interference (cross talk) for multicomponent measurements, high natural frequency, and broad dynamic range. It is pointed out that the limitations with respect to quasi-static measurements imposed by the drift of the zero point are not as extensive as generally believed, while drift correction methods improve the measurement accuracy.

  8. Nonlinearities of biopolymer gels increase the range of force transmission

    NASA Astrophysics Data System (ADS)

    Xu, Xinpeng; Safran, Samuel A.

    2015-09-01

    We present a model of biopolymer gels that includes two types of elastic nonlinearities, stiffening under extension and softening (due to buckling) under compression, to predict the elastic anisotropy induced by both external as well as internal (e.g., due to cell contractility) stresses in biopolymer gels. We show how the stretch-induced anisotropy and the strain-stiffening nonlinearity increase both the amplitude and power-law range of transmission of internal, contractile, cellular forces, and relate this to recent experiments.

  9. Nonlinearities of biopolymer gels increase the range of force transmission.

    PubMed

    Xu, Xinpeng; Safran, Samuel A

    2015-09-01

    We present a model of biopolymer gels that includes two types of elastic nonlinearities, stiffening under extension and softening (due to buckling) under compression, to predict the elastic anisotropy induced by both external as well as internal (e.g., due to cell contractility) stresses in biopolymer gels. We show how the stretch-induced anisotropy and the strain-stiffening nonlinearity increase both the amplitude and power-law range of transmission of internal, contractile, cellular forces, and relate this to recent experiments. PMID:26465519

  10. International Technology Exchange Division: 1993 Annual report

    SciTech Connect

    Not Available

    1993-12-31

    The Office of Technology Development (OTD) was established to ensure that reliable and acceptable technologies are available for implementation at DOE sites and that a technically trained work force is available to complete the EM mission by 2019. OTD established the International Technology Exchange Staff (ITES) to identify, evaluate, and acquire international technologies which can accelerate US DOE cleanup operations. ITES`s goal is to pursue international collaboration among government organizations, educational institutions, and private industry to identify world-wide needs and available technologies that will meet US environmental needs in general, and EM cleanup needs in particular; and establish mechanisms by which US government ER/WM technologies will be transferred to the US private sector for commercialization and export to international markets. ITES has developed the following strategic objectives to implement its international goals: develop and implement EM`s policy for international programs in accordance with DOE and US Government policies and regulations; establish efficient and predictable international technology transfer mechanisms; assist the US private sector in the commercialization and deployment of federally funded EM technologies and related knowledge in international markets; leverage US and non-US resources to accelerate international development and regulatory acceptance of EM technologies; contribute to the improvement of EM`s training of US students, scientists, and managers on international environmental issues. A summary and descriptions of program activities and accomplishments are given for 17 programs which comprise the four main areas of the ITES program: Activities with the Former Soviet Union, International Technology Transfer, International Cooperation, and Information Systems and Publications. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  11. The Community College of the Air Force

    ERIC Educational Resources Information Center

    Kaapke, Lyle D.; Wojciechowske, William A.

    1977-01-01

    The Community College of the Air Force is unique as a postsecondary occupational education institution because it integrates Air Force technical education and civilian-related education into programs which are totally responsive to the Air Force community. (JG)

  12. Note: Helical nanobelt force sensors

    SciTech Connect

    Hwang, G.; Hashimoto, H.

    2012-12-15

    We present the fabrication and characterization of helical nanobelt force sensors. These self-sensing force sensors are based on the giant piezoresistivity of helical nanobelts. The three-dimensional helical nanobelts are self-formed from 27 nm-thick n-type InGaAs/GaAs bilayers using rolled-up techniques, and assembled onto electrodes on a micropipette using nanorobotic manipulations. The helical nanobelt force sensors can be calibrated using a calibrated atomic force microscope cantilever system under scanning electron microscope. Thanks to their giant piezoresistance coefficient (515 Multiplication-Sign 10{sup -10} Pa{sup -1}), low stiffness (0.03125 N/m), large-displacement capability ({approx}10 {mu}m), and good fatigue resistance, they are well suited to function as stand-alone, compact ({approx}20 {mu}m without the plug-in support), light ({approx}5 g including the plug-in support), versatile and large range ({approx}{mu}N) and high resolution ({approx}nN) force sensors.

  13. Constructing the Self-Force

    NASA Astrophysics Data System (ADS)

    Poisson, Eric

    I present an overview of the methods involved in the computation of the scalar, electromagnetic, and gravitational self-forces acting on a point particle moving in a curved spacetime. For simplicity, the focus here will be on the scalar self-force. The lecture follows closely my review article on this subject [E. Poisson, Living Rev. Relativ. 7 (2004), http://www.livingreviews.org/lrr-2004-6]. I begin with a review of geometrical elements (Synge's world function, the parallel propagator). Next I introduce useful coordinate systems (Fermi normal coordinates and retarded light-cone coordinates) in a neighborhood of the particle's world line. I then present the wave equation for a scalar field in curved spacetime and the equations of motion for a particle endowed with a scalar charge. The wave equation is solved by means of a Green's function, and the self-force is constructed from the field gradient. Because the retarded field is singular on the world line, the self-force must involve a regularized version of the field gradient, and I describe how the regular piece of the self-field can be identified. In the penultimate section of the lecture I put the construction of the self-force on a sophisticated axiomatic basis, and in the concluding section I explain how one can do better by abandoning the dangerous fiction of a point particle.

  14. Forces driving epithelial wound healing

    NASA Astrophysics Data System (ADS)

    Brugués, Agustí; Anon, Ester; Conte, Vito; Veldhuis, Jim H.; Gupta, Mukund; Colombelli, Julien; Muñoz, José J.; Brodland, G. Wayne; Ladoux, Benoit; Trepat, Xavier

    2014-09-01

    A fundamental feature of multicellular organisms is their ability to self-repair wounds through the movement of epithelial cells into the damaged area. This collective cellular movement is commonly attributed to a combination of cell crawling and `purse-string’ contraction of a supracellular actomyosin ring. Here we show by direct experimental measurement that these two mechanisms are insufficient to explain force patterns observed during wound closure. At early stages of the process, leading actin protrusions generate traction forces that point away from the wound, showing that wound closure is initially driven by cell crawling. At later stages, we observed unanticipated patterns of traction forces pointing towards the wound. Such patterns have strong force components that are both radial and tangential to the wound. We show that these force components arise from tensions transmitted by a heterogeneous actomyosin ring to the underlying substrate through focal adhesions. The structural and mechanical organization reported here provides cells with a mechanism to close the wound by cooperatively compressing the underlying substrate.

  15. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V. C.; Wang, Chengpu

    2003-01-01

    An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

  16. Note: Helical nanobelt force sensors

    NASA Astrophysics Data System (ADS)

    Hwang, G.; Hashimoto, H.

    2012-12-01

    We present the fabrication and characterization of helical nanobelt force sensors. These self-sensing force sensors are based on the giant piezoresistivity of helical nanobelts. The three-dimensional helical nanobelts are self-formed from 27 nm-thick n-type InGaAs/GaAs bilayers using rolled-up techniques, and assembled onto electrodes on a micropipette using nanorobotic manipulations. The helical nanobelt force sensors can be calibrated using a calibrated atomic force microscope cantilever system under scanning electron microscope. Thanks to their giant piezoresistance coefficient (515 × 10-10 Pa-1), low stiffness (0.03125 N/m), large-displacement capability (˜10 μm), and good fatigue resistance, they are well suited to function as stand-alone, compact (˜20 μm without the plug-in support), light (˜5 g including the plug-in support), versatile and large range (˜μN) and high resolution (˜nN) force sensors.

  17. Note: helical nanobelt force sensors.

    PubMed

    Hwang, G; Hashimoto, H

    2012-12-01

    We present the fabrication and characterization of helical nanobelt force sensors. These self-sensing force sensors are based on the giant piezoresistivity of helical nanobelts. The three-dimensional helical nanobelts are self-formed from 27 nm-thick n-type InGaAs/GaAs bilayers using rolled-up techniques, and assembled onto electrodes on a micropipette using nanorobotic manipulations. The helical nanobelt force sensors can be calibrated using a calibrated atomic force microscope cantilever system under scanning electron microscope. Thanks to their giant piezoresistance coefficient (515 × 10(-10) Pa(-1)), low stiffness (0.03125 N/m), large-displacement capability (~10 μm), and good fatigue resistance, they are well suited to function as stand-alone, compact (~20 μm without the plug-in support), light (~5 g including the plug-in support), versatile and large range (~μN) and high resolution (~nN) force sensors. PMID:23278031

  18. Forces driving epithelial wound healing

    PubMed Central

    Veldhuis, Jim H.; Gupta, Mukund; Colombelli, Julien; Muñoz, José J.; Brodland, G. Wayne; Ladoux, Benoit; Trepat, Xavier

    2015-01-01

    A fundamental feature of multicellular organisms is their ability to self-repair wounds through the movement of epithelial cells into the damaged area. This collective cellular movement is commonly attributed to a combination of cell crawling and “purse-string” contraction of a supracellular actomyosin ring. Here we show by direct experimental measurement that these two mechanisms are insufficient to explain force patterns observed during wound closure. At early stages of the process, leading actin protrusions generate traction forces that point away from the wound, showing that wound closure is initially driven by cell crawling. At later stages, we observed unanticipated patterns of traction forces pointing towards the wound. Such patterns have strong force components that are both radial and tangential to the wound. We show that these force components arise from tensions transmitted by a heterogeneous actomyosin ring to the underlying substrate through focal adhesions. The structural and mechanical organization reported here provides cells with a mechanism to close the wound by cooperatively compressing the underlying substrate. PMID:27340423

  19. Summary of EC Superelement Results for OH Inter-Module Connecting Forces

    SciTech Connect

    Wands, R.; Weber, K.; Zurawski, J.; /Fermilab

    1987-05-26

    The purpose of this report is to summarize the OH module connecting forces found as a result of the super-element modeling of the EC internal module structure. Although not presented here, this approach can also provide MH connecting forces and assembly deflections. This report includes only information on the OH connecting forces for various assumed connector schemes. The super-element machinery is in place to model other connector ideas, and provide information on overall deflections, MH connecting forces, and primary module stresses.

  20. Submolecular features of epitaxially grown PTCDA on Cu(111) analyzed by force field spectroscopy.

    PubMed

    Braun, D-A; Weiner, D; Such, B; Fuchs, H; Schirmeisen, A

    2009-07-01

    Submolecular features of epitaxially grown 3,4,9,10-perylenetetra-carboxylic-dianhydride (PTCDA) on Cu(111) are resolved in non-contact atomic force microscopy topography scans in ultrahigh vacuum. While molecules in the first layer above the Cu substrate are depicted as featureless ovals, the second layer molecules show an intramolecular structure with a height corrugation of up to 40 pm. Force field spectroscopy experiments with submolecular resolution show that the tip-molecule forces differ significantly on the first and second layer molecules. Possible contributions to these force differences from mechanical deformations of the molecules as well as the internal charge density distribution are discussed. PMID:19509447