Science.gov

Sample records for internal forces

  1. Internal and External Forces in Language Change.

    ERIC Educational Resources Information Center

    Yang, Charles D.

    2000-01-01

    Develops a model of language change characterizing the dynamic interaction between internal universal grammar and external linguistic evidence, as mediated by language acquisition. Borrows insights from the study of biological evolution, where internal and external forces interact in similar fashion. Applies the model to explore the loss of the…

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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…

  8. 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.

  9. 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

  10. 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)

  11. 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

  12. Forced wave motion with internal and boundary damping

    NASA Astrophysics Data System (ADS)

    Louw, Tobias; Whitney, Scott; Subramanian, Anu; Viljoen, Hendrik

    2012-01-01

    A d'Alembert-based solution of forced wave motion with internal and boundary damping is presented with the specific intention of investigating the transient response. The dynamic boundary condition is a convenient method to model the absorption and reflection effects of an interface without considering coupled PDE's. Problems with boundary condition of the form ?w/?z+??w/?t =0 are not self-adjoint which greatly complicates solution by spectral analysis. However, exact solutions are found with d'Alembert's method. Solutions are also derived for a time-harmonically forced problem with internal damping and are used to investigate the effect of ultrasound in a bioreactor, particularly the amount of energy delivered to cultured cells. The concise form of the solution simplifies the analysis of acoustic field problems.

  13. 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.

  14. Modal decomposition of tidally-forced internal waves

    NASA Astrophysics Data System (ADS)

    Kaminski, A. K.; Flynn, M. R.

    2012-04-01

    There exist multiple mechanisms for the breaking of ocean internal waves including critical reflection, shear instabilities, etc. Wave breaking contributes to diapycnal mixing and sediment or nutrient transport. A principal mechanism of internal wave generation is tidal conversion, i.e. time-periodic sloshing of seawater over bathymetry such as the mid-Atlantic ridge. While past theoretical and laboratory experimental work has principally considered the scenario in which internal waves are forced by only one frequency, tidal flow has a range of diurnal and semi-diurnal frequency components (i.e. M2, S2, K1, etc.). Correspondingly, tidal conversion may generate a broad wave spectrum comprising different frequencies and vertical wavenumbers. Such details are relevant in estimating the location and amount of mixing that occurs upon wave breaking. In this work, an algorithm has been developed that performs a spatial and temporal decomposition of polychromatic internal waves generated by tidal sloshing over topography, with constant buoyancy frequency N. Starting with vertical velocity timeseries data of a given internal wave field, a fast Fourier transform (FFT) with windowing and zero-padding is employed in order to determine the (discrete) frequencies present. Frequency-specific complex mode strengths γjn for the internal waves can then be recovered. In order to verify the results of the algorithm, synthetic laboratory experimental data corresponding to the idealized problem of tidal sloshing over 2D Gaussian topography are generated and superposed for a variety of forcing frequencies (ranging fromωj/N = 1/10 toωj/N = 9/10). The calculated frequencies and mode strengths are compared with the known values from the synthetic data. The mode strengths γjn are either calculated directly or as a ratio normalized by the mode 1 mode strength. In either scenario, the resulting mode strengths can be sensitive to errors in the frequencies recovered via FFT. However, when exact frequencies are used the numerically calculated mode strengths show excellent qualitative and quantitative agreement with those from the synthetic data. The algorithm is currently being extended to the scenario in which the internal wave forcing frequencies form a continuous frequency spectrum rather than well-defined discrete peaks, such as those arising from fluid-fluid interactions (e.g. an intrusive gravity current propagating through a stratified ambient). Such wave fields present numerous additional challenges in the calculation of the associated mode strengths. The algorithm described above allows for the determination of the temporal and spatial structure of an internal wave field without a-priori knowledge of the specifics of its generation. Further adaptations such as variable N for realistic background stratification would allow for application to more geophysically relevant scenarios, and thus the analysis of observational data.

  15. 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.

  16. Report of the ACR task force on international teleradiology.

    PubMed

    Van Moore, Arl; Allen, Bibb; Campbell, Shannon C; Carlson, Richard A; Dunnick, N Reed; Fletcher, Thomas B; Hanks, J Daniel; Hauser, J Bruce; Moorefield, James M; Taxin, Richard N; Thrall, James H

    2005-02-01

    Telemedicine is becoming an increasingly important tool in the practice of medicine throughout the world. For radiologists, telemedicine translates to teleradiology. Because an increasing amount of imaging is now archived in a digital format, and with the application of more powerful computers in radiology, digital image transmission between display stations is becoming commonplace. The ability to move large diagnostic image data sets to display stations anywhere in the world using the Internet and other high-speed data links is solving some problems and creating others. Medicine and radiology will be challenged in many ways by the issues created from the application of this burgeoning technology. Our task force was charged with investigating the evolving practice of international teleradiology and with developing a pubic statement to be adopted by the ACR Council (). This white paper is our effort to define those issues we believe to be most pertinent to international teleradiology as we know them today. Will these issues be changing? Certainly. For some facets of the issue, there are currently more questions than answers. We describe several scenarios that we believe are acceptable practices of international teleradiology as well as some that are not. We believe that much will be written about international teleradiology in the future as the issues of credentialing, quality assurance, licensure, American Board of Radiology certification, the maintenance of certification, jurisdictional and medical liability issues, patient privacy, fraud and medical ethics are more precisely defined and shaped by state and federal legislation and medical jurisprudence. This white paper is our assessment of what we believe to be the major challenges that exist as of this writing. PMID:17411780

  17. 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.

  18. Internal Forces during Static Prehension: Effects of Age and Grasp Configuration

    PubMed Central

    Solnik, Stanislaw; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2014-01-01

    We studied effects of healthy aging on three components of the internal force vector during static prehensile tasks. Young and older subjects held an instrumented handle using a five-digit prismatic grasp under different digit configurations and external torques. Across digit configurations, older subjects showed larger internal normal (grip) and tangential (load-resisting) digit force components and larger internal moment of force. In contrast to earlier reports, safety margin values were not higher in the older subjects. The results show that the increased grip force in older persons is a specific example of a more general age-related problem reflected in the generation of large internal force vectors in prehensile tasks. It is possible that the higher internal forces increase the apparent stiffness of the “hand+handle” system and, hence, contribute to its stability. This strategy, however, may be maladaptive, energetically wasteful, and inefficient in ensuring safety of hand-held objects. PMID:24650078

  19. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

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

    PubMed

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

    2014-10-01

    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. PMID:25296792

  2. 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.

  3. 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…

  4. 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.

  5. Are External Knee Load and EMG Measures Accurate Indicators of Internal Knee Contact Forces during Gait?

    PubMed Central

    Meyer, Andrew J.; D'Lima, Darryl D.; Besier, Thor F.; Lloyd, David G.; Colwell, Clifford W.; Fregly, Benjamin J.

    2013-01-01

    Mechanical loading is believed to be a critical factor in the development and treatment of knee osteoarthritis. However, the contact forces to which the knee articular surfaces are subjected during daily activities cannot be measured clinically. Thus, the ability to predict internal knee contact forces accurately using external measures (i.e., external knee loads and muscle EMG signals) would be clinically valuable. This study quantifies how well external knee load and EMG measures predict internal knee contact forces during gait. A single subject with a force-measuring tibial prosthesis and post-operative valgus alignment performed four gait patterns (normal, medial thrust, walking pole, and trunk sway) to induce a wide range of external and internal knee joint loads. Linear regression analyses were performed to assess how much of the variability in internal contact forces was accounted for by variability in the external measures. Though the different gait patterns successfully induced significant changes in the external and internal quantities, changes in external measures were generally weak indicators of changes in total, medial, and lateral contact force. Our results suggest that when total contact force may be changing, caution should be exercised when inferring changes in knee contact forces based on observed changes in external knee load and EMG measures. Advances in musculoskeletal modeling methods may be needed for accurate estimation of in vivo knee contact forces. PMID:23280647

  6. Are external knee load and EMG measures accurate indicators of internal knee contact forces during gait?

    PubMed

    Meyer, Andrew J; D'Lima, Darryl D; Besier, Thor F; Lloyd, David G; Colwell, Clifford W; Fregly, Benjamin J

    2013-06-01

    Mechanical loading is believed to be a critical factor in the development and treatment of knee osteoarthritis. However, the contact forces to which the knee articular surfaces are subjected during daily activities cannot be measured clinically. Thus, the ability to predict internal knee contact forces accurately using external measures (i.e., external knee loads and muscle electromyographic [EMG] signals) would be clinically valuable. We quantified how well external knee load and EMG measures predict internal knee contact forces during gait. A single subject with a force-measuring tibial prosthesis and post-operative valgus alignment performed four gait patterns (normal, medial thrust, walking pole, and trunk sway) to induce a wide range of external and internal knee joint loads. Linear regression analyses were performed to assess how much of the variability in internal contact forces was accounted for by variability in the external measures. Though the different gait patterns successfully induced significant changes in the external and internal quantities, changes in external measures were generally weak indicators of changes in total, medial, and lateral contact force. Our results suggest that when total contact force may be changing, caution should be exercised when inferring changes in knee contact forces based on observed changes in external knee load and EMG measures. Advances in musculoskeletal modeling methods may be needed for accurate estimation of in vivo knee contact forces. PMID:23280647

  7. 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

  8. 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.

  9. Anomalies of ac driven solitary waves with internal modes: nonparametric resonances induced by parametric forces.

    PubMed

    Quintero, N R; Sánchez, A; Mertens, F G

    2001-10-01

    We study the dynamics of kinks in the straight phi(4) model subjected to a parametric ac force, both with and without damping, as a paradigm of solitary waves with internal modes. By using a collective coordinate approach, we find that the parametric force has a nonparametric effect on the kink motion. Specifically, we find that the internal mode leads to a resonance for frequencies of the parametric driving close to its own frequency, in which case the energy of the system grows as well as the width of the kink. These predictions of the collective coordinate theory are verified by numerical simulations of the full partial differential equation. We finally compare this kind of resonance with that obtained for nonparametric ac forces and conclude that the effect of ac drivings on solitary waves with internal modes is exactly the opposite of their character in the partial differential equation. PMID:11690164

  10. 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.

  11. 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)

  12. International Dimensions of the University of Alberta. Report of the Senate Task Force.

    ERIC Educational Resources Information Center

    Alberta Univ., Edmonton.

    This report, written by the University of Alberta (Canada) Senate Task Force, was created to facilitate discussion and propose actions to facilitate internationalization of the campus. The report reviews how the university's current activities and strengths might be leveraged to enhance its international stature. It examines a multitude of factors…

  13. 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…

  14. Cogging force rejection method of linear motor based on internal model principle

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Zhenyu; Yang, Tianbo

    2015-02-01

    The cogging force disturbance of linear motor is one of the main factors affecting the positioning accuracy of ultraprecision moving platform. And this drawback could not be completely overcome by improving the design of motor body, such as location modification of permanent magnet array, or optimization design of the shape of teeth-slot. So the active compensation algorithms become prevalent in cogging force rejection area. This paper proposed a control structure based on internal mode principle to attenuate the cogging force of linear motor which deteriorated the accuracy of position, and this structure could make tracking and anti-disturbing performance of close-loop designed respectively. In the first place, the cogging force was seen as the intrinsic property of linear motor and its model constituting controlled object with motor ontology model was obtained by data driven recursive identification method. Then, a control structure was designed to accommodate tracking and anti-interference ability separately by using internal model principle. Finally, the proposed method was verified in a long stroke moving platform driven by linear motor. The experiment results show that, by employing this control strategy, the positioning error caused by cogging force was decreased by 70%.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. Ice flexure forced by internal wave packets in the arctic ocean.

    PubMed

    Czipott, P V; Levine, M D; Paulson, C A; Menemenlis, D; Farmer, D M; Williams, R G

    1991-11-01

    Tiltmeters on the Arctic Ocean were used to measure flexure of the ice forced by an energetic packet of internal waves riding the crest of diurnal internal bores emanating from the Yermak Plateau, north of the Svalbard Archipelago. The waves forced an oscillatory excursion of 36 microradians in tilt of the ice, corresponding to an excursion of 16 micrometers per second in vertical velocity at the surface and of 3.5 millimeters in surface displacement. Strainmeters embedded in the ice measured an excursion of 3 x 10(-7) in strain, consistent with ice flexure rather than compression. The measured tilt is consistent with direct measurements of excursions in horizontal current near the surface (12 centimeters per second) and in vertical displacement (36 meters) of the pycnocline 100 meters below the surface. PMID:17787172

  20. The future of general internal medicine. Report and recommendations from the Society of General Internal Medicine (SGIM) Task Force on the Domain of General Internal Medicine.

    PubMed

    Larson, Eric B; Fihn, Stephan D; Kirk, Lynne M; Levinson, Wendy; Loge, Ronald V; Reynolds, Eileen; Sandy, Lewis; Schroeder, Steven; Wenger, Neil; Williams, Mark

    2004-01-01

    The Society of General Internal Medicine asked a task force to redefine the domain of general internal medicine. The task force believes that the chaos and dysfunction that characterize today's medical care, and the challenges facing general internal medicine, should spur innovation. These are our recommendations: while remaining true to its core values and competencies, general internal medicine should stay both broad and deep-ranging from uncomplicated primary care to continuous care of patients with multiple, complex, chronic diseases. Postgraduate and continuing education should develop mastery. Wherever they practice, general internists should be able to lead teams and be responsible for the care their teams give, embrace changes in information systems, and aim to provide most of the care their patients require. Current financing of physician services, especially fee-for-service, must be changed to recognize the value of services performed outside the traditional face-to-face visit and give practitioners incentives to improve quality and efficiency, and provide comprehensive, ongoing care. General internal medicine residency training should be reformed to provide both broad and deep medical knowledge, as well as mastery of informatics, management, and team leadership. General internal medicine residents should have options to tailor their final 1 to 2 years to fit their practice goals, often earning a certificate of added qualification (CAQ) in special generalist fields. Research will expand to include practice and operations management, developing more effective shared decision making and transparent medical records, and promoting the close personal connection that both doctors and patients want. We believe these changes constitute a paradigm shift that can benefit patients and the public and reenergize general internal medicine. PMID:14748863

  1. 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.

  2. Analysis of combined natural and forced convection in vertical semicircular ducts with radial internal fins

    SciTech Connect

    Dong, Z.F.; Ebadian, M.A.

    1995-03-01

    A numerical analysis of combined natural and forced convection is conducted for the fully developed laminar flow and heat transfer in a vertical semicircular duct with radial, internal longitudinal fins. Accurate solutions for heating upward flow are obtained by the finite difference method based on a fine grid, while the hydraulic and thermal conditions of the fins are ascertained. The results represent a range of Raleigh numbers and various values of fin lengths and number of fins. The fully developed f Re and Nu values for pure forced convection in the finned semicircular duct are also documented. It is found that both the friction factor and the Nusselt number in the finned tube increase as the Raleigh number increases. The effect of buoyancy is significant in semicircular ducts with short fins. By comparing the results of finless ducts with those of finned ducts, it was concluded that heat transfer in combined natural and forced convection in the semicircular duct is dramatically enhanced by using radial internal fins.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Research Priorities and Plans for the International Space Station - Results of the REMAP Task Force

    NASA Astrophysics Data System (ADS)

    Kicza, M.

    2002-01-01

    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. The U.S. President's Budget language for 2003 states that "...NASA will be working with the White House Office of Science and Technology Policy (OSTP) to engage the scientific community and establish clear high-priority, affordable science objectives with near-term focus on improving scientific productivity. The results of this review will help set the science agenda for Biological and Physical Research that will in turn define how the Space Station is used." In consultation with OSTP and the Office of Management and budget (OMB), NASA's Office of Biological and Physical Research (OBPR) is assembling an ad-hoc external advisory committee, the Biological and Physical REsearch MAximization and Prioritization (REMAP) Task Force, which will be under the auspices of the NASA Advisory Council. This paper will describe the outcome of the Task Force and how it will be used to define a roadmap for near and long term Biological and Physical Research objectives. Additionally the paper will discuss the maximization of the International Space Station utilization.

  9. 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.

  10. Policy lessons from comparing mortality from two global forces: international terrorism and tobacco

    PubMed Central

    Thomson, George; Wilson, Nick

    2005-01-01

    Background The aim of this study was to compare the mortality burdens from two global impacts on mortality: international terrorism and the major cause of preventable death in developed countries – tobacco use. We also sought to examine the similarities and differences between these two causes of mortality so as to better inform the policy responses directed at prevention. Methods Data on deaths from international terrorism were obtained from a US State Department database for 1994–2003. Estimates for tobacco-attributable deaths were based on Peto et al 2003. The countries were 37 developed and East European countries. Results and discussion The collective annualized mortality burden from tobacco was approximately 5700 times that of international terrorism. The ratio of annual tobacco to international terrorism deaths was lowest for the United States at 1700 times, followed by Russia at 12,900 times. The tobacco death burden in all these countries was equivalent to the impact of an 11 September type terrorist attack every 14 hours. Different perceptions of risk may contribute to the relative lack of a policy response to tobacco mortality, despite its relatively greater scale. The lack is also despite tobacco control having a stronger evidence base for the prevention measures used. Conclusion This comparison highlights the way risk perception may determine different policy responses to global forces causing mortality. Nevertheless, the large mortality differential between international terrorism and tobacco use has policy implications for informing the rational use of resources to prevent premature death. PMID:16354305

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. International PV QA Task Force's proposed comparative rating system for PV modules

    NASA Astrophysics Data System (ADS)

    Wohlgemuth, John; Kurtz, Sarah

    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.

  16. 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. PMID:24030475

  17. Boundary forced internal waves in a non-uniform stratification: diminution and resonant pathways to instability

    NASA Astrophysics Data System (ADS)

    Ghaemsaidi, Sasan John; Peacock, Thomas

    2015-11-01

    We study the surface forcing of internal waves in a non-uniform stratification comprising a relatively thin, highly stratified upper layer sitting atop a deep, weakly stratified lower layer. Such a system theoretically yields a range of transmission features for harmonic boundary forcing, with the response ranging from diminution to resonant growth depending on the degree of coherence between the constitutive waves in the upper stratification layer. A series of laboratory experiments are performed in order to investigate the role of wave interference in tuning wave transmission. We find that the occurrence of destructive interference in the upper stratification naturally yields diminution of the transmitted wave. Conversely, constructive interference results in a notable amplification of the wave field over time scales on the order of the forcing period; the development of nonlinear wave-wave interactions due to wave amplification is observed over longer time scales. Good agreement is obtained between the experimental results and a weakly viscous, long wave model of our system within the linear regime.

  18. 14th International Congress on Antiphospholipid Antibodies Task Force report on obstetric antiphospholipid syndrome.

    PubMed

    de Jesus, Guilherme R; Agmon-Levin, Nancy; Andrade, Carlos A; Andreoli, Laura; Chighizola, Cecilia B; Porter, T Flint; Salmon, Jane; Silver, Robert M; Tincani, Angela; Branch, D Ware

    2014-08-01

    Pregnancy morbidity is one of the clinical manifestations used for classification criteria of antiphospholipid syndrome (APS). During the 14th International Congress on Antiphospholipid Antibodies (aPL), a Task Force with internationally-known experts was created to carry out a critical appraisal of the literature available regarding the association of aPL with obstetric manifestations present in actual classification criteria (recurrent early miscarriage, fetal death, preeclampsia and placental insufficiency) and the quality of the evidence that treatment(s) provide benefit in terms of avoiding recurrent adverse obstetric outcomes. The association of infertility with aPL and the effectiveness of the treatment of patients with infertility and positive aPL was also investigated. This report presents current knowledge and limitations of published studies regarding pregnancy morbidity, infertility and aPL, identifying areas that need better investigative efforts and proposing how critical flaws could be avoided in future studies, as suggested by participants of the Task Force. Except for fetal death, there are limitations in the quality of the data supporting the association of aPL with obstetric complications included in the current APS classification criteria. Recommended treatments for all pregnancy morbidity associated to APS also lack well-designed studies to confirm its efficacy. APL does not seem to be associated with infertility and treatment does not improve the outcomes in infertile patients with aPL. In another section of the Task Force, Dr. Jane Salmon reviewed complement-mediated inflammation in reproductive failure in APS, considering new therapeutic targets to obstetric APS (Ob APS). PMID:24650941

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

    NASA Astrophysics Data System (ADS)

    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

    2016-03-01

    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.

  20. 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

  1. 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

  2. 14th International Congress on Antiphospholipid Antibodies: task force report on antiphospholipid syndrome treatment trends.

    PubMed

    Erkan, Doruk; Aguiar, Cassyanne L; Andrade, Danieli; Cohen, Hannah; Cuadrado, Maria J; Danowski, Adriana; Levy, Roger A; Ortel, Thomas L; Rahman, Anisur; Salmon, Jane E; Tektonidou, Maria G; Willis, Rohan; Lockshin, Michael D

    2014-06-01

    Antiphospholipid Syndrome (APS) is characterized by vascular thrombosis and/or pregnancy morbidity occurring in patients with persistent antiphospholipid antibodies (aPL). The primary objective of the APS Treatment Trends Task Force, created as part of the 14th International Congress on aPL, was to systematically review the potential future treatment strategies for aPL-positive patients. The task force chose as future clinical research directions: a) determining the necessity for controlled clinical trials in venous thromboembolism with the new oral direct thrombin or anti-factor Xa inhibitors pending the results of the ongoing rivaroxaban in APS (RAPS) trial, and designing controlled clinical trials in other forms of thrombotic APS; b) systematically analyzing the literature as well as aPL/APS registries, and creating specific registries for non-warfarin/heparin anticoagulants; c) increasing recruitment for an ongoing primary thrombosis prevention trial, and designing secondary thrombosis and pregnancy morbidity prevention trials with hydroxychloroquine; d) determining surrogate markers to select patients for statin trials; e) designing controlled studies with rituximab and other anti-B-cell agents; f) designing mechanistic and clinical studies with eculizumab and other complement inhibitors; and g) chemically modifying peptide therapy to improve the half-life and minimize immunogenicity. The report also includes recommendations for clinicians who consider using these agents in difficult-to-manage aPL-positive patients. PMID:24468415

  3. 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.

  4. 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.

  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. 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.

  7. [The internal consistency of corrected labor force data in the census (1960-1980) and the estimation of labor force participation rates by age and sex for 1980].

    PubMed

    Morelos, J B

    1993-01-01

    This work examines the internal consistency of corrected estimates of the economically active population in the Mexican censuses of 1960 through 1980, estimates participation rates by age and sex for 1980, and determines the degree of overestimation or underestimation of the 1980 census. The first section reviews results of evaluations of information on the active population and examines the internal consistency of the different estimates. The second establishes criteria for correction of participation rates by age and sex for 1980 and estimates the degree of overestimation or underestimation, and the third assesses the advantages and limitations of the results. Comparison of results from several studies suggests that the labor force was significantly overestimated in the 1960 and 1980 censuses and underestimated in the censuses of 1970 and 1990. Estimates of overestimation in the 1960 census ranged from 8.5 to 14.3%, while estimates of underestimation in 1970 ranged from -0.5% to -0.8%. Estimates of overestimation in 1980 ranged from 6.6% to 21.6%. Internal consistency of labor force data was also assessed through a comparative analysis of average rates of growth of the population aged 12 and over and of the economically active population according to the census and the various corrections. The study concluded that the female labor force was overestimated by 1.6 million workers in 1980, or 27.1%, while the male labor force was overestimated by 610,000 workers, or 4%. The total labor force was overestimated by around 10%. These estimates for 1980 appear more congruent with general trends in male and female labor force participation, and also with the rate of growth of the population over age 12. PMID:12288660

  8. 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.

  9. 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

  10. 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

  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 Japan and the South China Sea regions, while the linkage to equatorial basin-scale SSTA is weak at best. A large scale SSTA dipole with warming (cooling) in the subtropical central (eastern) Pacific foreshadows a strong SEAM.

  12. Forced-air warming design: evaluation of intake filtration, internal microbial buildup, and airborne-contamination emissions.

    PubMed

    Reed, Mike; Kimberger, Oliver; McGovern, Paul D; Albrecht, Mark C

    2013-08-01

    Forced-air warming devices are effective for the prevention of surgical hypothermia. However, these devices intake nonsterile floor-level air, and it is unknown whether they have adequate filtration measures to prevent the internal buildup or emission of microbial contaminants. We rated the intake filtration efficiency of a popular current-generation forced-air warming device (Bair Hugger model 750, Arizant Healthcare) using a monodisperse sodium chloride aerosol in the laboratory. We further sampled 23 forced-air warming devices (same model) in daily hospital use for internal microbial buildup and airborne-contamination emissions via swabbing and particle counting. Laboratory testing found the intake filter to be 63.8% efficient. Swabbing detected microorganisms within 100% of the forced-air warming blowers sampled, with isolates of coagulase-negative staphylococci, mold, and micrococci identified. Particle counting showed 96% of forced-air warming blowers to be emitting significant levels of internally generated airborne contaminants out of the hose end. These findings highlight the need for upgraded intake filtration, preferably high-efficiency particulate air filtration (99.97% efficient), on current-generation forced-air warming devices to reduce contamination buildup and emission risks. PMID:24133849

  13. 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 from the extensive analysis of conformational properties of glycoprotein structures reported in the Protein Data Bank. Use of the BPMC search leads to significant improvements in sampling efficiency for glycan simulations. Moreover, good agreement with the X-ray glycoprotein structures is achieved for all glycan chain lengths. Thus, average/median RMSDs are 0.81/0.68 Å for one-residue glycans and 1.32/1.47 Å for three-residue glycans. RMSD from the native structure for the lowest-energy conformation of the 12-residue glycan chain (PDB ID 3og2) is 1.53 Å. Additionally, results obtained for free short oligosaccharides using the new force field are in line with the available experimental data, i.e., the most populated conformations in solution are predicted to be the lowest energy ones. The newly developed parameters allow for the accurate modeling of linear and branched hexopyranose glycosides in heterogeneous systems. PMID:25999804

  14. The International Neuroblastoma Risk Group (INRG) Staging System: An INRG Task Force Report

    PubMed Central

    Monclair, Tom; Brodeur, Garrett M.; Ambros, Peter F.; Brisse, Hervé J.; Cecchetto, Giovanni; Holmes, Keith; Kaneko, Michio; London, Wendy B.; Matthay, Katherine K.; Nuchtern, Jed G.; von Schweinitz, Dietrich; Simon, Thorsten; Cohn, Susan L.; Pearson, Andrew D.J.

    2009-01-01

    Purpose The International Neuroblastoma Risk Group (INRG) classification system was developed to establish a consensus approach for pretreatment risk stratification. Because the International Neuroblastoma Staging System (INSS) is a postsurgical staging system, a new clinical staging system was required for the INRG pretreatment risk classification system. Methods To stage patients before any treatment, the INRG Task Force, consisting of neuroblastoma experts from Australia/New Zealand, China, Europe, Japan, and North America, developed a new INRG staging system (INRGSS) based on clinical criteria and image-defined risk factors (IDRFs). To investigate the impact of IDRFs on outcome, survival analyses were performed on 661 European patients with INSS stages 1, 2, or 3 disease for whom IDRFs were known. Results In the INGRSS, locoregional tumors are staged L1 or L2 based on the absence or presence of one or more of 20 IDRFs, respectively. Metastatic tumors are defined as stage M, except for stage MS, in which metastases are confined to the skin, liver, and/or bone marrow in children younger than 18 months of age. Within the 661-patient cohort, IDRFs were present (ie, stage L2) in 21% of patients with stage 1, 45% of patients with stage 2, and 94% of patients with stage 3 disease. Patients with INRGSS stage L2 disease had significantly lower 5-year event-free survival than those with INRGSS stage L1 disease (78% ± 4% v 90% ± 3%; P = .0010). Conclusion Use of the new staging (INRGSS) and risk classification (INRG) of neuroblastoma will greatly facilitate the comparison of risk-based clinical trials conducted in different regions of the world. PMID:19047290

  15. 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

  16. "Having It All" at Sleep's Expense: The Forced Choice of Participants in Advanced Placement Courses and International Baccalaureate Programs

    ERIC Educational Resources Information Center

    Foust, Regan Clark; Hertberg-Davis, Holly; Callahan, Carolyn M.

    2008-01-01

    The gifted can suffer from too many demands on their time and attention. This qualitative study tested the theory that advanced placement (AP) and international baccalaureate (IB) participants may feel forced to choose between academic success and social acceptance. The results, however, did not support the theory. Not only did gifted students not…

  17. Prediction and compensation by an internal model for back forces during finger opening in an overarm throw.

    PubMed

    Hore, J; Watts, S; Tweed, D

    1999-09-01

    Previous studies have indicated that timing of finger opening in an overarm throw is likely controlled centrally, possibly by means of an internal model of hand trajectory. The present objective was to extend the study of throwing to an examination of the dynamics of finger opening. Throwing a heavy ball and throwing a light ball presumably require different neural commands, because the weight of the ball affects the mechanics of the arm, and particularly, the mechanics of the finger. Yet finger control is critical to the accuracy of an overarm throw. We hypothesized that finger opening in an overarm throw is controlled by a central mechanism that uses an internal model to predict and compensate for movement-dependent back forces on the fingers. To test this idea we determined whether finger motion is affected by back forces, i.e., whether larger back forces cause larger finger extensions. Back forces were varied by having subjects throw, at the same fast speed, tennis-sized balls of different weights (14, 55, and 196 g). Arm- and finger-joint rotations were recorded with the search-coil technique; forces on the middle finger were measured with force transducers. Recordings showed that during ball release, the middle finger experienced larger back forces in throws with heavier balls. Nevertheless, most subjects showed proximal interphalangeal joint extensions that were unchanged or actually smaller with the heavier balls. This was the case for the first throw and for all subsequent throws with a ball of a new weight. This suggests that the finger flexors compensated for the larger back forces by exerting larger torques during finger extension. Supporting this view, at the moment of ball release, all finger joints flexed abruptly due to the now unopposed torques of the finger flexors, and the amplitude of this flexion was proportional to ball weight. We conclude that in overarm throws made with balls of different weights, the CNS predicts the different back forces from the balls and adjusts finger flexor torques accordingly. This is consistent with the view that finger opening in overarm throws is controlled by means of an internal model of the motor apparatus and the external load. PMID:10482738

  18. 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, or a previous presumptive diagnosis of IE and drug-resistance with a single antiepileptic drug titrated to the highest tolerable dose.This consensus article represents the basis for a more standardised diagnostic approach to the seizure patient. These recommendations will evolve over time with advances in neuroimaging, electroencephalography, and molecular genetics of canine epilepsy. PMID:26316175

  19. Preventing suicide in prisons, part I. Recommendations from the International Association for Suicide Prevention Task Force on Suicide in Prisons.

    PubMed

    Konrad, Norbert; Daigle, Marc S; Daniel, Anasseril E; Dear, Greg E; Frottier, Patrick; Hayes, Lindsay M; Kerkhof, Ad; Liebling, Alison; Sarchiapone, Marco

    2007-01-01

    In 2000 the Department of Mental Health of the World Health Organization (WHO) published a guide named Preventing Suicide. A Resource for Prison Officers as part of the WHO worldwide initiative for the prevention of suicide. In 2007 there are new epidemiological data on prison suicide, a more detailed discussion of risk factors accounting for the generally higher rate of suicide in correctional settings in comparison to the general population, and several strategies for developing screening instruments. As a first step, this paper presents an update of the WHO guide by the Task Force on Suicide in Prisons, created by the International Association for Suicide Prevention. A second paper, by the same Task Force, will present some international comparisons of suicide prevention services in correctional facilities. PMID:17992824

  20. Introduction to the IEEE International Symposium on Applications of Ferroelectrics and International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials.

    PubMed

    Ye, Zuo-Guang; Tan, Xiaoli; Bokov, Alexei A

    2012-09-01

    The 20th IEEE International Symposium on Applications of Ferroelectrics (ISAF) was held on July 24-27, 2011, in Vancouver, British Columbia, Canada, jointly with the International Symposium on Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials (PFM). Over a period of four days, approximately 400 scientists, engineers, and students from around the world presented their work and discussed the latest developments in the field of ferroelectrics, related materials, and their applications. It is particularly encouraging to see that a large number of students (115) were attracted to the joint conference and presented high-quality research works. This trend is not only important to this conference series, but more importantly, it is vital to the future of the ferroelectrics field. PMID:23007749

  1. PREFACE: NC-AFM 2003: Proceedings of the 6th International Conference on Non-contact Atomic Force Microscopy

    NASA Astrophysics Data System (ADS)

    Reichling, Michael

    2004-02-01

    Direct nanoscale and atomic resolution imaging is a key issue in nanoscience and nanotechnology. The invention of the dynamic force microscope in the early 1990s was an important step forward in this direction as this instrument provides a universal tool for measuring the topography and many other physical and chemical properties of surfaces at the nanoscale. Operation in the so-called non-contact mode now allows direct atomic resolution imaging of electrically insulating surfaces and nanostructures which has been an unsolved problem during the first decade of nanotechnology. Today, we face a most rapid development of the technique and an extension of its capabilities far beyond imaging; atomically resolved force spectroscopy provides information about local binding properties and researchers now develop sophisticated schemes of force controlled atomic manipulation with the tip of the force microscope. Progress in the field of non-contact force microscopy is discussed at the annually held NC-AFM conferences that are part of a series started in 1998 with a meeting in Osaka, Japan. The 6th International Conference on Non-contact Atomic Force Microscopy took place in Dingle, Ireland, from 31 August to 3 September 2003 and this special issue is a compilation of the original publications of work presented at this meeting. The papers published here well reflect recent achievements, current trends and some of the challenging new directions in non-contact force microscopy that have been discussed during the most stimulating conference days in Dingle. Fundamental aspects of forces and dissipation relevant in imaging and spectroscopy have been covered by experimental and theoretical contributions yielding a more detailed understanding of tip--surface interaction in force microscopy. Novel and improved imaging and spectroscopy techniques have been introduced that either improve the performance of force microscopy or pave the way towards new functionalities and applications. With regard to studies on the specific systems investigated, there was a strong emphasis on oxides and ionics, as well as on organic systems. Following previous pioneering work in uncovering the atomic structure of insulating oxides with force microscopy, it was shown in the meeting that this important class of materials is now accessible for a quantitative atomic scale surface characterization. Single organic molecules and ordered organic layers are building blocks for functional nanostructures currently developed in many laboratories for applications in molecular electronics and sensor technologies. The Dingle conference impressively demonstrated that dynamic force microscopy is ready for its application as an analytical tool for these promising future nanotechnologies. The meeting was a great success scientifically and participants enjoyed the beauty of the conference site. I would like to thank all members of the international steering committee, the programme committee and the co-chairs, J Pethica, A Shluger and G Thornton, for their efforts in preparing the meeting. The members of the local organising committee, J Ballentine-Armstrong, G Cross, S Dunne, S Jarvis and Ö Özer, kept the meeting running smoothly and created a very pleasant atmosphere. The generous financial support from Science Foundation Ireland (SFI), is greatly appreciated; SFI is dramatically raising the profile of Irish science. I would also like to express my sincere gratitude to N Couzin and the journal team from Institute of Physics Publishing for their editorial management and perfect co-operation in the preparation of this special issue.

  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. 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

  4. Heat transfer in a gray tube with forced convection, internal radiation and axial wall conduction

    NASA Astrophysics Data System (ADS)

    Chung, B. T. F.; Thompson, J. E.

    1983-11-01

    A method of successive approximations is employed to solve the problem of heat transfer to a transparent gas flowing through a radiating-conducting tube with turbulent forced convection between the tube wall and the gas, and with energy generation in the wall. Emphasis is given to the effect of emissivity of the wall to the tube and gas temperature profiles.

  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. Surface structure. Subatomic resolution force microscopy reveals internal structure and adsorption sites of small iron clusters.

    PubMed

    Emmrich, Matthias; Huber, Ferdinand; Pielmeier, Florian; Welker, Joachim; Hofmann, Thomas; Schneiderbauer, Maximilian; Meuer, Daniel; Polesya, Svitlana; Mankovsky, Sergiy; Kdderitzsch, Diemo; Ebert, Hubert; Giessibl, Franz J

    2015-04-17

    Clusters built from individual iron atoms adsorbed on surfaces (adatoms) were investigated by atomic force microscopy (AFM) with subatomic resolution. Single copper and iron adatoms appeared as toroidal structures and multiatom clusters as connected structures, showing each individual atom as a torus. For single adatoms, the toroidal shape of the AFM image depends on the bonding symmetry of the adatom to the underlying structure [twofold for copper on copper(110) and threefold for iron on copper(111)]. Density functional theory calculations support the experimental data. The findings correct our previous work, in which multiple minima in the AFM signal were interpreted as a reflection of the orientation of a single front atom, and suggest that dual and triple minima in the force signal are caused by dimer and trimer tips, respectively. PMID:25791086

  7. 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.

  8. 77 FR 29899 - Safety Zone; International Special Operations Forces Week Capability Exercise, Seddon Channel...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... in the vicinity of the Tampa Convention Center in Tampa, Florida during the International Special... Channel, in the vicinity of the Tampa Convention Center in Tampa, Florida. The exercise will consist of... Tampa Convention Center in Tampa, Florida. The safety zone will be enforced from 12:30 p.m. until 3:30...

  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. 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

  11. 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

  12. Variability of the shelf break jet in the Middle Atlantic Bight: Internally or externally forced?

    NASA Astrophysics Data System (ADS)

    Fratantoni, P. S.; Pickart, R. S.

    2003-05-01

    Velocity records from two bottom-mounted acoustic Doppler current profilers, deployed at the shelf break south of New England are used to characterize the mesoscale variability of the shelf break frontal jet in the Middle Atlantic Bight. While on average the jet is equatorward, energetic current fluctuations dominate the 18-month record at a period near 13 days. The fluctuations are characterized by a deceleration in the equatorward flow over the full water column and are strong enough to reverse the jet near the bottom. The origin of the observed variability is explored with the help of local wind records, concurrent velocity measurements from three tall current meter moorings deployed over the continental slope, and Gulf Stream frontal position information. While we are unable to attribute definitively the observed variability to a single forcing mechanism, we are able to discount several of the traditional possibilities. These include local effects, such as wind driving and tidal rectification, as well as offshore forcing due to Gulf Stream rings, topographic Rossby waves, and the meandering of the Gulf Stream. It is most probable that the fluctuations are caused by baroclinic instability of the shelf break jet. However, we are not able to determine this unequivocally, as our records differ from historical observations of instabilities, and stability models tend to oversimplify the salient features of the jet.

  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. The International Neuroblastoma Risk Group (INRG) Classification System: An INRG Task Force Report

    PubMed Central

    Cohn, Susan L.; Pearson, Andrew D.J.; London, Wendy B.; Monclair, Tom; Ambros, Peter F.; Brodeur, Garrett M.; Faldum, Andreas; Hero, Barbara; Iehara, Tomoko; Machin, David; Mosseri, Veronique; Simon, Thorsten; Garaventa, Alberto; Castel, Victoria; Matthay, Katherine K.

    2009-01-01

    Purpose Because current approaches to risk classification and treatment stratification for children with neuroblastoma (NB) vary greatly throughout the world, it is difficult to directly compare risk-based clinical trials. The International Neuroblastoma Risk Group (INRG) classification system was developed to establish a consensus approach for pretreatment risk stratification. Patients and Methods The statistical and clinical significance of 13 potential prognostic factors were analyzed in a cohort of 8,800 children diagnosed with NB between 1990 and 2002 from North America and Australia (Children's Oncology Group), Europe (International Society of Pediatric Oncology Europe Neuroblastoma Group and German Pediatric Oncology and Hematology Group), and Japan. Survival tree regression analyses using event-free survival (EFS) as the primary end point were performed to test the prognostic significance of the 13 factors. Results Stage, age, histologic category, grade of tumor differentiation, the status of the MYCN oncogene, chromosome 11q status, and DNA ploidy were the most highly statistically significant and clinically relevant factors. A new staging system (INRG Staging System) based on clinical criteria and tumor imaging was developed for the INRG Classification System. The optimal age cutoff was determined to be between 15 and 19 months, and 18 months was selected for the classification system. Sixteen pretreatment groups were defined on the basis of clinical criteria and statistically significantly different EFS of the cohort stratified by the INRG criteria. Patients with 5-year EFS more than 85%, more than 75% to ≤ 85%, ≥ 50% to ≤ 75%, or less than 50% were classified as very low risk, low risk, intermediate risk, or high risk, respectively. Conclusion By defining homogenous pretreatment patient cohorts, the INRG classification system will greatly facilitate the comparison of risk-based clinical trials conducted in different regions of the world and the development of international collaborative studies. PMID:19047291

  15. Atmospheric impacts of Arctic sea-ice loss, 1979-2009: separating forced change from atmospheric internal variability

    NASA Astrophysics Data System (ADS)

    Screen, James A.; Deser, Clara; Simmonds, Ian; Tomas, Robert

    2014-07-01

    The ongoing loss of Arctic sea-ice cover has implications for the wider climate system. The detection and importance of the atmospheric impacts of sea-ice loss depends, in part, on the relative magnitudes of the sea-ice forced change compared to natural atmospheric internal variability (AIV). This study analyses large ensembles of two independent atmospheric general circulation models in order to separate the forced response to historical Arctic sea-ice loss (1979-2009) from AIV, and to quantify signal-to-noise ratios. We also present results from a simulation with the sea-ice forcing roughly doubled in magnitude. In proximity to regions of sea-ice loss, we identify statistically significant near-surface atmospheric warming and precipitation increases, in autumn and winter in both models. In winter, both models exhibit a significant lowering of sea level pressure and geopotential height over the Arctic. All of these responses are broadly similar, but strengthened and/or more geographically extensive, when the sea-ice forcing is doubled in magnitude. Signal-to-noise ratios differ considerably between variables and locations. The temperature and precipitation responses are significantly easier to detect (higher signal-to-noise ratio) than the sea level pressure or geopotential height responses. Equally, the local response (i.e., in the vicinity of sea-ice loss) is easier to detect than the mid-latitude or upper-level responses. Based on our estimates of signal-to-noise, we conjecture that the local near-surface temperature and precipitation responses to past Arctic sea-ice loss exceed AIV and are detectable in observed records, but that the potential atmospheric circulation, upper-level and remote responses may be partially or wholly masked by AIV.

  16. Instability and mixing of stratified shear layers forced by internal wave strain

    NASA Astrophysics Data System (ADS)

    Kaminski, Alexis; Taylor, John

    2015-11-01

    Mixing of the stably-stratified ocean interior plays an important role in determining the vertical stratification and the transport of key biological and geochemical tracers. Shear instabilities are thought to be a key mechanism in triggering small-scale mixing in the ocean, and a large literature is devoted to examining the stability properties of steady, parallel stratified shear flows. However, geophysical flows are frequently complicated by additional processes, such as internal waves, leading to variation in space and in time. Not only is the breaking of internal waves an important source of mixing, but the vertical strain caused by these waves may also impact the stability of the flows through which they propagate. Here, we idealize this process by imposing a standing wave which is spatially and temporally periodic onto a stably-stratified shear flow. We use a direct-adjoint looping method to examine the linear stability of this complicated base flow over a range of parameters in order to identify and quantify the effect of the wave strain on the overall flow stability. Direct numerical simulations are then used to examine the nonlinear evolution and subsequent mixing.

  17. Treating spondyloarthritis, including ankylosing spondylitis and psoriatic arthritis, to target: recommendations of an international task force

    PubMed Central

    Smolen, Josef S; Braun, Jürgen; Dougados, Maxime; Emery, Paul; FitzGerald, Oliver; Helliwell, Philip; Kavanaugh, Arthur; Kvien, Tore K; Landewé, Robert; Luger, Thomas; Mease, Philip; Olivieri, Ignazio; Reveille, John; Ritchlin, Christopher; Rudwaleit, Martin; Schoels, Monika; Sieper, Joachim; de Wit, Martinus; Baraliakos, Xenofon; Betteridge, Neil; Burgos-Vargas, Ruben; Collantes-Estevez, Eduardo; Deodhar, Atul; Elewaut, Dirk; Gossec, Laure; Jongkees, Merryn; Maccarone, Mara; Redlich, Kurt; van den Bosch, Filip; Wei, James Cheng-Chung; Winthrop, Kevin; van der Heijde, Désirée

    2014-01-01

    Background Therapeutic targets have been defined for diseases like diabetes, hypertension or rheumatoid arthritis and adhering to them has improved outcomes. Such targets are just emerging for spondyloarthritis (SpA). Objective To define the treatment target for SpA including ankylosing spondylitis and psoriatic arthritis (PsA) and develop recommendations for achieving the target, including a treat-to-target management strategy. Methods Based on results of a systematic literature review and expert opinion, a task force of expert physicians and patients developed recommendations which were broadly discussed and voted upon in a Delphi-like process. Level of evidence, grade and strength of the recommendations were derived by respective means. The commonalities between axial SpA, peripheral SpA and PsA were discussed in detail. Results Although the literature review did not reveal trials comparing a treat-to-target approach with another or no strategy, it provided indirect evidence regarding an optimised approach to therapy that facilitated the development of recommendations. The group agreed on 5 overarching principles and 11 recommendations; 9 of these recommendations related commonly to the whole spectrum of SpA and PsA, and only 2 were designed separately for axial SpA, peripheral SpA and PsA. The main treatment target, which should be based on a shared decision with the patient, was defined as remission, with the alternative target of low disease activity. Follow-up examinations at regular intervals that depend on the patient's status should safeguard the evolution of disease activity towards the targeted goal. Additional recommendations relate to extra-articular and extramusculoskeletal aspects and other important factors, such as comorbidity. While the level of evidence was generally quite low, the mean strength of recommendation was 9–10 (10: maximum agreement) for all recommendations. A research agenda was formulated. Conclusions The task force defined the treatment target as remission or, alternatively, low disease activity, being aware that the evidence base is not strong and needs to be expanded by future research. These recommendations can inform the various stakeholders about expert opinion that aims for reaching optimal outcomes of SpA. PMID:23749611

  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.

    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

  20. 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.

  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. The effect of host cluster gravitational tidal forces on the internal dynamics of spiral galaxies

    NASA Astrophysics Data System (ADS)

    Mayer, Alexander

    2013-04-01

    New empirical observation by Bidin, Carraro, Mendez & Smith finds ``a lack of dark matter in the Solar neighborhood" (2012 ApJ 751, 30). This, and the discovery of a vast polar structure of Milky Way satellites by Pawlowski, Pflamm-Altenburg & Kroupa (2012 MNRAS 423, 1109), conflict with the prevailing interpretation of the measured Galactic rotation curve. Simulating the dynamical effects of host cluster tidal forces on galaxy disks reveals radial migration in a spiral structure and an orbital velocity that accelerates with increasing galactocentric radial coordinate. A virtual ``toy model,'' which is based on an Earth-orbiting system of particles and is physically realizable in principle, is available at GravitySim.net. Given the perturbing gravitational effect of the host cluster on a spiral galaxy disk and that a similar effect does not exist for the Solar System, the two systems represent distinct classes of gravitational dynamical systems. The observed `flat' and accelerating rotation curves of spiral galaxies can be attributed to gravitational interaction with the host cluster; no `dark matter halo' is required to explain the observable.

  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 treatment outcome suggested. (5) Reach agreement on minimum standards of care, minimum record collection, and reach consensus on simple outcome measures in all disciplines. This should include all cleft types and all ages. These standards could be used to encourage governments to fund multidisciplinary care. (6) Teams will be encouraged to start and continue recordkeeping using simple and agreed protocols, according to agreed standards of minimum records and later share their data with other teams and then, embark on outcome studies. (7) Teams already active in research should: Create a register for cleft professionals and teams to reach agreement of contemporary and comprehensive multidisciplinary outcome measures, explore the possibilities using modern technology and plan large multi-national studies. A patient/parent centered data collection should always be included. These studies need funding. One task could also be exploring whether health care at a distance could be initiated using new technology. PMID:25244656

  4. 14th International Congress on Antiphospholipid Antibodies Task Force. Report on antiphospholipid syndrome laboratory diagnostics and trends.

    PubMed

    Bertolaccini, Maria Laura; Amengual, Olga; Andreoli, Laura; Atsumi, Tatsuya; Chighizola, Cecilia B; Forastiero, Ricardo; de Groot, Philip; Lakos, Gabriella; Lambert, Marc; Meroni, Pierluigi; Ortel, Thomas L; Petri, Michelle; Rahman, Anisur; Roubey, Robert; Sciascia, Savino; Snyder, Melissa; Tebo, Anne E; Tincani, Angela; Willis, Rohan

    2014-09-01

    Current classification criteria for definite Antiphospholipid Syndrome (APS) require the use of three laboratory assays to detect antiphospholipid antibodies (aCL, anti-β2GPI and LA) in the presence of at least one of the two major clinical manifestations (i.e. thrombosis or pregnancy morbidity) of the syndrome. However, several other autoantibodies shown to be directed to other proteins or their complex with phospholipids have been proposed to be relevant to APS but their clinical utility and their diagnostic value remains elusive. This report summarizes the findings, conclusions and recommendations of the "APS Task Force 3-Laboratory Diagnostics and Trends" meeting that took place during the 14th International Congress on Antiphospholipid Antibodies (APLA 2013, September 18-21, Rio de Janeiro, RJ, Brazil). PMID:24824074

  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 disease, especially comorbidity and shared decision-making with the patient. Levels of evidence had increased for many items compared with the 2010 recommendations, and levels of agreement were very high for most of the individual recommendations (≥9/10). Conclusions The 4 overarching principles and 10 recommendations are based on stronger evidence than before and are supposed to inform patients, rheumatologists and other stakeholders about strategies to reach optimal outcomes of RA. PMID:25969430

  6. Screening for adolescent idiopathic scoliosis: an information statement by the scoliosis research society international task force

    PubMed Central

    2013-01-01

    Background Routine screening of scoliosis is a controversial subject and screening efforts vary greatly around the world. Methods Consensus was sought among an international group of experts (seven spine surgeons and one clinical epidemiologist) using a modified Delphi approach. The consensus achieved was based on careful analysis of a recent critical review of the literature on scoliosis screening, performed using a conceptual framework of analysis focusing on five main dimensions: technical, clinical, program, cost and treatment effectiveness. Findings A consensus was obtained in all five dimensions of analysis, resulting in 10 statements and recommendations. In summary, there is scientific evidence to support the value of scoliosis screening with respect to technical efficacy, clinical, program and treatment effectiveness, but there insufficient evidence to make a statement with respect to cost effectiveness. Scoliosis screening should be aimed at identifying suspected cases of scoliosis that will be referred for diagnostic evaluation and confirmed, or ruled out, with a clinically significant scoliosis. The scoliometer is currently the best tool available for scoliosis screening and there is moderate evidence to recommend referral with values between 5 degrees and 7 degrees. There is moderate evidence that scoliosis screening allows for detection and referral of patients at an earlier stage of the clinical course, and there is low evidence suggesting that scoliosis patients detected by screening are less likely to need surgery than those who did not have screening. There is strong evidence to support treatment by bracing. Interpretation This information statement by an expert panel supports scoliosis screening in 4 of the 5 domains studied, using a framework of analysis which includes all of the World Health Organisation criteria for a valid screening procedure. PMID:24171910

  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. 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.

  9. 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

  10. 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 exceed the yield strength of the country rocks, effectively making eruption possible independent of any external triggers. Our simulations reveal that the Peach Spring and Bishop Tuff magmatic systems represent two contrasting types of behavior. In the Bishop case, only ~5-25 wt.% of crystallization over a short temperature interval (~30 °C cooling) is needed to reach near-invariant behavior, making it plausible that crystallization led to eruption without external triggers. This is consistent with the lack of evidence for interaction of Bishop magma with mafic magmas. In the Peach Spring case, 30-70 wt. % crystallization over a much longer temperature interval (~60-130 °C cooling) is needed for the system to reach the near-invariant. Given that Peach Spring pumice and fiamme are characterized by <30 wt. % crystals, it seems unlikely that crystallization alone led to eruption, suggesting the action of an external trigger in promoting eruption. This is consistent with evidence for significant heating and mush remobilization preserved in intracaldera Peach Spring rocks. Our results show that phase-equilibria constrains whether a magma system is likely to destabilize itself and erupt as a result of overpressurization by closed-system crystallization and volatile exsolution.

  11. 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 atomic resolution, the investigation of near-surface electronic states, the quantification of adhesion forces, and the lateral mapping of surface potentials. The origin of energy dissipation, which is closely related to an in-depth understanding of tip-surface interactions and imaging mechanisms, was the subject of an ongoing discussion and addressed by various theoretical, computational, and experimental contributions. A characteristic of the NC-AFM conference series is the lively and friendly atmosphere, which year after year stimulates scientific discussions between the participants. This time, the programme included 5 invited talks, 84 contributed presentations, and 113 participants; furthermore, three educational lectures were given as part of a pre-conference workshop targeted at NC-AFM newcomers, which was attended by 30 participants. I would like to thank the members of the international steering committee and the programme committee for their continued effort in organizing the meeting. Special thanks go to the chair of the programme and local organizing committees S Fain and the conference manager J Kvamme for making the meeting a success. Financial support is acknowledged from the corporate sponsors MikroMasch USA, Nanonis GmbH, Nanosurf AG, Omicron Nanotechnology, PSIA, Inc., and RHK Technology, as well as from the institutional sponsors National Science Foundation and PNNL/UW Joint Institute for Nanoscience. Finally, I would like to express my gratitude to everyone who participated in assembling this special issue including the authors, the reviewers, and, in particular, the excellent and experienced journal team from the Institute of Physics Publishing headed by Nina Couzin, for devoting their time and efforts so that we could make this issue a useful representation of the progress in NC-AFM while maintaining our tight publication schedule. In conclusion, I would like to mention that the Seattle conference was the first one of the NC-AFM series that took place in the USA. As such, it was part of a series of recent activities within the USA, which will help in establishing a strong domestic NC-AFM community.

  12. 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 spineespecially in the three lower vertebraehas 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.

  13. 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 (?=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 C? 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 for 4 residues loops, 0.84/0.46 for 8 residue loops, and 1.16/0.73 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

  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. 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

  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 exchange among participants. We hope that all of the participants enjoyed the activities of the conference and the town of Kobe. We are indebted to the members of the international steering committee and the local organizing committee for this successful conference. The operation of conference business by the Kobe Convention and Visitors Association, and by the staff in Professor Morita's lab in Osaka University, and Professor Onishi's lab in Kobe University, is greatly acknowledged. We would like to express our sincere gratitude to the 167th committee on Nano-probe Technology of Japan Society for the Promotion of Science, Nanotechnology Researchers Network Center of Japan, Foundation Advanced Technology Institute, Tsutomu Nakauchi Foundation, and all of the exhibitors at the conference for their financial support. The funding from Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, is greatly appreciated and enabled these proceedings to be published by IOP Publishing (IOP). We also thank the editorial staff of IOP for their professional work in publishing this special issue.

  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. International.

    ERIC Educational Resources Information Center

    Hoover, Linn

    1979-01-01

    The International Geological Correlation Project has attained scientific maturity and broad support and participation by geologists world wide. Its purpose is to provide a mechanism for international cooperation and information exchange about geological problems that transcend national boundaries. (Author/BB)

  20. 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 formation allow the highly resolved measurement of a number of physical properties far beyond the determination of surface topography. The development of techniques allowing atomic resolution dynamic mode imaging in liquids pushes the door open for an atomic precision analysis of biological samples under physiological conditions. In each of these fields, the conference demonstrated cutting-edge results and also provided perspectives for the next steps on the roadmap of NC-AFM towards the development of its full extent. The conference in Bad Essen was made possible by the continuous dedication of the local management and we are most grateful to Frauke Riemann, Joachim Fontaine and the members of the supporting team for the smooth organization. We gratefully appreciate the financial support of the exhibitors, namely Anfatec, HALCYONICS, JEOL, LOT-Oriel, NanoMagnetics, NT-MDT, Omicron, Schaefer Technology, SURFACE, UNISOKU and the local sponsors which enabled us to provide free participation at the conference for ten promising young researchers who had submitted excellent contributions. It was a great pleasure for us to continue our most successful collaboration with Nanotechnology as our partner for the proceedings publication and we would like to thank Ian Forbes and the publishing team for the professional handling of the peer review and all production matters.

  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. Internal radiation exposure of Ground Self-Defense Force members involved in the management of the Fukushima Nuclear Power Plant disaster.

    PubMed

    Naoi, Yutaka; Fujikawa, Akira; Kyoto, Yukishige; Kunishima, Naoaki; Ono, Masahiro; Watanabe, Yukie

    2013-01-01

    When the Great East Japan Earthquake occurred on March 11, 2011, the Ground Self-Defense Force (GSDF) was dispatched nationally to Northeast area in Japan. The highly trained GSDF members were simultaneously assigned to various missions for the Fukushima Nuclear Power Plants disaster. The missions of GSDF terminated on August 31, 2011. Special medical examinations were conducted for the members as they returned to each military unit. GSDF members who were assigned to the nuclear power plant were at risk of radiation exposure; therefore, pocket dosimeters were used to assess external radiation exposure. A few months after the mission was terminated, measurements of internal radiation exposure were performed. This is the first report of the internal exposure of GSDF members who worked in the restricted radiation contamination area. Here, we report the amounts of internal and external exposure of and the equipment used by the GSDF members. PMID:24352931

  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. Cookery method and end-point temperature can affect the Warner-Bratzler shear force, cooking loss, and internal cooked color of beef longissimus steaks.

    PubMed

    Yancey, J W S; Wharton, M D; Apple, J K

    2011-05-01

    Steaks from 60 beef ribeye rolls were used to test the interactive effects of cookery method and end-point temperature on Warner-Bratzler shear force (WBSF) and internal cooked color. Pairs of longissimus thoracis (LT) steaks were assigned to combinations of 3 different end-point temperatures and 5 cookery methods. The forced-air convection oven (FAC) required the longest time and produced the reddest internal color, regardless of end-point temperature. The clam-shell grill (CLAM) required the least cooking time and resulted in the lowest cooking losses, but CLAM-cooked steaks also had the greatest WBSF values and least red internal color. Repeatability values for WBSF were acceptable (>0.60) for all degrees of doneness when steaks were cooked in the FAC and impingement oven, but steaks cooked on the CLAM were not repeatable. The relationship of myofibrillar toughening, moisture loss and cooked color changes in beef LT steaks also differed due to cookery methods. PMID:21185659

  5. Adverse event reporting tool to standardize the reporting and tracking of adverse events during procedural sedation: a consensus document from the World SIVA International Sedation Task Force.

    PubMed

    Mason, K P; Mason, Keira P; Green, S M; Piacevoli, Q

    2012-01-01

    Currently, there are no established definitions or terminology for sedation-related adverse events (AEs). With clear terminology and definitions, sedation events may be accurately identified and tracked, providing a benchmark for defining the occurrence of AEs, ranging from minimal to severe. This terminology could apply to sedation performed in any location and by any provider. We present a consensus document from the International Sedation Task Force (ISTF) of the World Society of Intravenous Anaesthesia (World SIVA). The ISTF is composed of adult and paediatric sedation practitioners from multiple disciplines throughout the world. PMID:22157446

  6. 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…

  7. 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…

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  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. 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

  15. 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.

  16. Partitioning of knee joint internal forces in gait is dictated by the knee adduction angle and not by the knee adduction moment.

    PubMed

    Adouni, M; Shirazi-Adl, A

    2014-05-01

    Medial knee osteoarthritis is a debilitating disease. Surgical and conservative interventions are performed to manage its progression via reduction of load on the medial compartment or equivalently its surrogate measure, the external adduction moment. However, some studies have questioned a correlation between the medial load and adduction moment. Using a musculoskeletal model of the lower extremity driven by kinematics-kinetics of asymptomatic subjects at gait midstance, we aim here to quantify the relative effects of changes in the knee adduction angle versus changes in the adduction moment on the joint response and medial/lateral load partitioning. The reference adduction rotation of 1.6° is altered by ±1.5° to 3.1° and 0.1° or the knee reference adduction moment of 17Nm is varied by ±50% to 25.5Nm and 8.5Nm. Quadriceps, hamstrings and tibiofemoral contact forces substantially increased as adduction angle dropped and diminished as it increased. The medial/lateral ratio of contact forces slightly altered by changes in the adduction moment but a larger adduction rotation hugely increased this ratio from 8.8 to a 90 while in contrast a smaller adduction rotation yielded a more uniform distribution. If the aim in an intervention is to diminish the medial contact force and medial/lateral load ratio, a drop of 1.5° in adduction angle is much more effective (causing respectively 12% and 80% decreases) than a reduction of 50% in the adduction moment (causing respectively 4% and 13% decreases). Substantial role of changes in adduction angle is due to the associated alterations in joint nonlinear passive resistance. These findings explain the poor correlation between knee adduction moment and tibiofemoral compartment loading during gait suggesting that the internal load partitioning is dictated by the joint adduction angle. PMID:24636718

  17. 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

  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. Effects of composite and coordinated interactions between populations of particle-like individuals involving forces and internal states — A statistical-mechanical study

    NASA Astrophysics Data System (ADS)

    Øien, Alf H.

    2008-09-01

    In this analogue modeling of interacting species we consider in particular interactions we refer to as composite interactions between particles called “daphnicles” and “food particles” that evolve on a third particle component in the background. Other force interactions are also taken account of but they play a smaller role in this study. The states of daphnicles and food particles are not only given by their position- and velocity-variables but also by variables of internal properties they have, which we shall call “saturation” for daphnicles and “nutrition” for food particles. The “laws” of variations of all these variables, where the rates of change of saturation and nutrition take place in the central region of the force interaction range where daphnicles and food particles come close together in their movements, are coupled in the composite interactions we consider. Due to this coupling of the “outer” force interaction to the “inner” saturation-nutrition interaction the inner interaction can be raised or diminished and in this way the distribution of say saturation of daphnicles may be regulated. From an extended Liouville equation for a system of a large number of particles where in particular interactions like these are baked in on the level of individual particles we aim to derive equations for daphnicle and food particle distribution functions on a kinetic level; this derivation constitutes the main part of the paper. Proper equations on a coarser grained level of description are then found quite easily: this “mixed” kinetic/moment level is in between the kinetic- and the full moment (macroscopic) levels such that distribution of saturation and nutrition still play a role and the equations still retain essential characteristics of the composite interactions taking place on the microscopic level, besides other force interactions. Though the terminology used suites modeling of biological systems and the results may throw some light on earlier modeling of daphnia behavior, the modeling is also believed to have relevance to systems of interacting species outside this area. The paper gives some examples and results of particular interaction models at the end.

  20. 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 thorough understanding of the fluvial system and, in particular, basin-wide assessment of resilience to human-induced change. . The framework proposed has allowed producing high-dimensional samples of spatially distributed geomorphic drivers at catchment scale while integrating recent and historic point records for the Red River basin. This novel dataset has been then analysed using self-organizing maps (SOM) an artificial neural network model in combination with fuzzy clustering. The above framework is able to identify non-trivial correlations in driving forces and to derive a fuzzy classification at reach scale which represents continuities and discontinuities in the river systems. The use of the above framework allowed analyzing the spatial distribution of geomorphic features at catchment scale, revealing patterns of similarities and dissimilarities within the catchment and allowing a classification of river reaches characterized by similar geomorphic drivers, fluvial processes and response to external forcing. The paper proposes an innovative and promising technique to produce hydromorphological classifications at catchment scale integrating historical and recent available high resolution data. The framework aims at opening the way to a more structured organization and analyses of recently available information on river geomorphic features, so far often missing or rarely exploited. This approach poses the basis to produce efficient databases of river geomorphic features and processes related to natural and anthropogenic drivers. That is a necessity in order to enhance our understanding of the internal and external forces which drive fluvial systems, to assess the resilience and dynamic of river landscapes and to develop the more efficient river management strategies of the future.

  1. 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.

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

    PubMed Central

    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, Mg2+-induced switch between two alternative conformations: from ‘open’, elongated morphologies at 0–2 mM Mg2+ concentration to a ‘closed’, comma-shaped conformation at 4–6 mM Mg2+. 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 Mg2+ 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

  3. Drag force acting on a neuromast in the fish lateral line trunk canal. I. Numerical modelling of external-internal flow coupling.

    PubMed

    Barbier, Charlotte; Humphrey, Joseph A C

    2009-07-01

    Fishes use a complex, multi-branched, mechanoreceptive organ called the lateral line to detect the motion of water in their immediate surroundings. This study is concerned with a subset of that organ referred to as the lateral line trunk canal (LLTC). The LLTC consists of a long tube no more than a few millimetres in diameter embedded immediately under the skin of the fish on each side of its body. In most fishes, pore-like openings are regularly distributed along the LLTC, and a minute sensor enveloped in a gelatinous cupula, referred to as a neuromast, is located between each pair of pores. Drag forces resulting from fluid motions induced inside the LLTC by pressure fluctuations in the external flow stimulate the neuromasts. This study, Part I of a two-part sequence, investigates the motion-sensing characteristics of the LLTC and how it may be used by fishes to detect wakes. To this end, an idealized geometrical/dynamical situation is examined that retains the essential problem physics. A two-level numerical model is developed that couples the vortical flow outside the LLTC to the flow stimulating the neuromasts within it. First, using a Navier-Stokes solver, we calculate the unsteady flow past an elongated rectangular prism and a fish downstream of it, with both objects moving at the same speed. By construction, the prism generates a clean, periodic vortex street in its wake. Then, also using the Navier-Stokes solver, the pressure field associated with this external flow is used to calculate the unsteady flow inside the LLTC of the fish, which creates the drag forces acting on the neuromast cupula. Although idealized, this external-internal coupled flow model allows an investigation of the filtering properties and performance characteristics of the LLTC for a range of frequencies of biological interest. The results obtained here and in Part II show that the LLTC acts as a low-pass filter, preferentially damping high-frequency pressure gradient oscillations, and hence high-frequency accelerations, associated with the external flow. PMID:18926967

  4. Drag force acting on a neuromast in the fish lateral line trunk canal. I. Numerical modelling of external–internal flow coupling

    PubMed Central

    Barbier, Charlotte; Humphrey, Joseph A.C.

    2008-01-01

    Fishes use a complex, multi-branched, mechanoreceptive organ called the lateral line to detect the motion of water in their immediate surroundings. This study is concerned with a subset of that organ referred to as the lateral line trunk canal (LLTC). The LLTC consists of a long tube no more than a few millimetres in diameter embedded immediately under the skin of the fish on each side of its body. In most fishes, pore-like openings are regularly distributed along the LLTC, and a minute sensor enveloped in a gelatinous cupula, referred to as a neuromast, is located between each pair of pores. Drag forces resulting from fluid motions induced inside the LLTC by pressure fluctuations in the external flow stimulate the neuromasts. This study, Part I of a two-part sequence, investigates the motion-sensing characteristics of the LLTC and how it may be used by fishes to detect wakes. To this end, an idealized geometrical/dynamical situation is examined that retains the essential problem physics. A two-level numerical model is developed that couples the vortical flow outside the LLTC to the flow stimulating the neuromasts within it. First, using a Navier–Stokes solver, we calculate the unsteady flow past an elongated rectangular prism and a fish downstream of it, with both objects moving at the same speed. By construction, the prism generates a clean, periodic vortex street in its wake. Then, also using the Navier–Stokes solver, the pressure field associated with this external flow is used to calculate the unsteady flow inside the LLTC of the fish, which creates the drag forces acting on the neuromast cupula. Although idealized, this external–internal coupled flow model allows an investigation of the filtering properties and performance characteristics of the LLTC for a range of frequencies of biological interest. The results obtained here and in Part II show that the LLTC acts as a low-pass filter, preferentially damping high-frequency pressure gradient oscillations, and hence high-frequency accelerations, associated with the external flow. PMID:18926967

  5. 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 with limited brain metastases. Intensity-modulated radiation therapy provides an excellent technique to reduce dose to the carotids in head and neck cancer and improves locoregional control in oesophageal cancer. Best practice and research priorities are summarised. PMID:24625455

  6. 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.

  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. Electroweak Force

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The united force that encompasses the electromagnetic force and the weak nuclear force. The unification of these two forces is described by a theory that was devised during the 1960s by Sheldon Glashow, Steven Weinberg and Abdus Salam according to which, at high enough energies, the electromagnetic force and the weak nuclear interaction behave in exactly the same way....

  9. Analysis and comparison of diurnal variations of cloud radiative forcing: Earth Radiation Budget Experiment and International Satellite Cloud Climatology Project results

    NASA Technical Reports Server (NTRS)

    Kim, Yongseung

    1994-01-01

    Cloud radiative forcing (CRF) is the radiative impact of clouds on the Earth's radiation budget. This study examines the diurnal variations of CRF using the Earth Radiation Budget Experiment (ERBE) monthly hourly flux data and the flux data derived from the International Satellite Cloud Climatology Project (ISCCP) using the Goddard Institute for Space Studies general circulation model radiation code. The results for the months of April, July, and October 1985 and January 1986 are analyzed. We found that, in general, two data sets agreed. For longwave (LW) CRF the diurnal range over land is generally greater than that observed over oceans. For the 4-month averages the ERBE values are 15.8 W/sq m and 6.8 W/sq m for land and ocean, respectively, compared with the ISCCP calculated values of 18.4 W/sq m and 8.0 W/sq m, respectively. The land/ocean contrast is largely associated with changes in cloud amount and the temperature difference between surface and cloud top. It would be more important to note that the clear-sky flux (i.e., surface temperature) variabilities are shown to be a major contributor to the large variabilities over land. The maximum diurnal range is found to be in the summer hemisphere, and the minimum values in the winter hemisphere. It is also shown that the daytime maximum and the nighttime minimum are seen over large portions of land, whereas they occur at any local hour over most oceans. For shortwave (SW) CRF the daytime maximum values are about twice as large as monthly averages, and their highest frequency occurs at local noon, indicating that solar insolation is a primary factor for the diurnal variation of SW CRF. However, the comparison of the ERBE data with the ISCCP results demonstrated that the largest differences in the diurnal range and monthly mean of LW CRF were associated with tropical convergence zones, where clear-sky fluxes could be easily biased by persistent cloudiness and the inadequate treatment of the atmospheric water vapor.

  10. 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

  11. Internalized HIV and Drug Stigmas: Interacting Forces Threatening Health Status and Health Service Utilization Among People with HIV Who Inject Drugs in St. Petersburg, Russia.

    PubMed

    Calabrese, Sarah K; Burke, Sara E; Dovidio, John F; Levina, Olga S; Uusküla, Anneli; Niccolai, Linda M; Heimer, Robert

    2016-01-01

    Marked overlap between the HIV and injection drug use epidemics in St. Petersburg, Russia, puts many people in need of health services at risk for stigmatization based on both characteristics simultaneously. The current study examined the independent and interactive effects of internalized HIV and drug stigmas on health status and health service utilization among 383 people with HIV who inject drugs in St. Petersburg. Participants self-reported internalized HIV stigma, internalized drug stigma, health status (subjective rating and symptom count), health service utilization (HIV care and drug treatment), sociodemographic characteristics, and health/behavioral history. For both forms of internalized stigma, greater stigma was correlated with poorer health and lower likelihood of service utilization. HIV and drug stigmas interacted to predict symptom count, HIV care, and drug treatment such that individuals internalizing high levels of both stigmas were at elevated risk for experiencing poor health and less likely to access health services. PMID:26050155

  12. Internal capillary-gravity waves of a two-layer fluid with free surface over an obstruction--Forced extended KdV equation

    NASA Astrophysics Data System (ADS)

    Choi, J. W.; Sun, S. M.; Shen, M. C.

    1996-02-01

    In this paper we study steady capillary-gravity waves in a two-layer fluid bounded above by a free surface and below by a horizontal rigid boundary with a small obstruction. Two critical speeds for the waves are obtained. Near the smaller critical speed, the derivation of the usual forced KdV equation (FKdV) fails when the coefficient of the nonlinear term in the FKdV vanishes. To overcome this difficulty, a new equation, called a forced extended KdV equation (FEKdV) governing interfacial wave forms, is obtained by a refined asymptotic method. Various solutions and numerical results of this equation are presented.

  13. 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)

  14. Basic Education in Developing Countries. Hearing before the International Task Force of the Select Committee on Hunger. House of Representatives, One Hundredth Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Select Committee on Hunger.

    The responsibility of the U.S. House of Representatives Task Force on Hunger is to investigate the causes and dimensions of world hunger and to develop legislative recommendations addressing the issues raised. At this hearing, the issue discussed was of basic education as a crucial link in expanding opportunities for poor and hungry people to…

  15. Measurement of muscle actions and foot reaction forces from crew members during entire working days on the International Space Station (ISS)

    NASA Astrophysics Data System (ADS)

    Snedeker, Jess G.; Cavanagh, Peter R.

    2000-01-01

    We present pilot work in preparation for ISS Experiment 318, which will investigate changes in lower limb daily mechanical loading and muscular activity profiles that have been implicated in bone mineral loss and muscle atrophy during spaceflight. Prototype equipment for the musculo-skeletal rack of the Human Research Facility (HRF) was used in conjunction with the Ambulatory Data Acquisition System to record and store data. Right foot ground reaction force profiles, right leg EMG activity profiles from the tibialis anterior and vastus medialis, and joint angular excursion profiles from the right knee and ankle were collected during five minutes each of forward and backward running in 1g as well as over a twelve hour period of activities during daily living. Ground reaction force profiles were analyzed to provide an estimate of 1g daily mechanical load stimulus, while EMG and joint angle profiles characterized the role of individual muscles in generating and absorbing energy. .

  16. 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…

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

    PubMed Central

    VELLAS, B.; FIELDING, R.; MILLER, R.; ROLLAND, Y.; BHASIN, S.; MAGAZINER, J.; BISCHOFF-FERRARI, H.

    2015-01-01

    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

  18. 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

  19. 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

  20. 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).

  1. The persistence length of DNA is reached from the persistence length of its null isomer through an internal electrostatic stretching force.

    PubMed

    Manning, Gerald S

    2006-11-15

    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

  2. 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

  3. 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 the United States. 301.7701-8 Section 301.7701-8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT... 301.7701-8 Military or naval forces and Armed Forces of the United States. The term military or...

  4. A general solution procedure for the forced vibrations of a system with cubic nonlinearities: Three-to-one internal resonances with external excitation

    NASA Astrophysics Data System (ADS)

    Burak Özhan, B.; Pakdemirli, Mehmet

    2010-06-01

    A general vibrational model of a continuous system with arbitrary linear and cubic operators is considered. Approximate analytical solutions are found using the method of multiple scales. The primary resonances of the external excitation and three-to-one internal resonances between two arbitrary natural frequencies are treated. The amplitude and phase modulation equations are derived. The steady-state solutions and their stability are discussed. The solution algorithm is applied to two specific problems: (1) axially moving Euler-Bernoulli beam, and (2) axially moving viscoelastic beam.

  5. 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,...

  6. 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,...

  7. 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,...

  8. 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,...

  9. 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

  10. 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…

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. EULAR recommendations for the management of early arthritis: report of a task force of the European Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT)

    PubMed Central

    Combe, B; Landewe, R; Lukas, C; Bolosiu, H D; Breedveld, F; Dougados, M; Emery, P; Ferraccioli, G; Hazes, J M W; Klareskog, L; Machold, K; Martin‐Mola, E; Nielsen, H; Silman, A; Smolen, J; Yazici, H

    2007-01-01

    Objective To formulate EULAR recommendations for the management of early arthritis. Methods In accordance with EULAR's “standardised operating procedures”, the task force pursued an evidence based approach and an approach based on expert opinion. A steering group comprised of 14 rheumatologists representing 10 European countries. The group defined the focus of the process, the target population, and formulated an operational definition of “management”. Each participant was invited to propose issues of interest regarding the management of early arthritis or early rheumatoid arthritis. Fifteen issues for further research were selected by use of a modified Delphi technique. A systematic literature search was carried out. Evidence was categorised according to usual guidelines. A set of draft recommendations was proposed on the basis of the research questions and the results of the literature search.. The strength of the recommendations was based on the category of evidence and expert opinion. Results 15 research questions, covering the entire spectrum of “management of early arthritis”, were formulated for further research; and 284 studies were identified and evaluated. Twelve recommendations for the management of early arthritis were selected and presented with short sentences. The selected statements included recognition of arthritis, referral, diagnosis, prognosis, classification, and treatment of early arthritis (information, education, non‐pharmacological interventions, pharmacological treatments, and monitoring of the disease process). On the basis of expert opinion, 11 items were identified as being important for future research. Conclusions 12 key recommendations for the management of early arthritis or early rheumatoid arthritis were developed, based on evidence in the literature and expert consensus. PMID:16396980

  17. 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.

  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. 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...

  20. 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...

  1. 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...

  2. 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

    2016-01-01

    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

  3. Uptake and use of recommendations for the diagnosis, severity scoring and management of chronic GVHD: an international survey of the EBMT-NCI Chronic GVHD Task Force.

    PubMed

    Duarte, R F; Greinix, H; Rabin, B; Mitchell, S A; Basak, G; Wolff, D; Madrigal, J A; Pavletic, S Z; Lee, S J

    2014-01-01

    In 2005, the National Institutes of Health (NIH) consensus conference published a series of papers recommending methods to improve the conduct of clinical trials in chronic GVHD. Although the NIH recommendations were primarily aimed at strengthening research, several papers addressed issues relevant for clinical practice, particularly diagnosis, severity scoring, and ancillary and supportive care practices. We conducted an international survey to assess the uptake of these recommendations, identify barriers to greater use and document the use and perceived effectiveness of available treatments. The response rate for the American survey of 1387 practitioners was 21.8%, and it was 24.6% for 407 centers surveyed in Europe, Asia, Australia and Africa. Most respondents were familiar with the NIH consensus recommendations (94-96%) and used them in practice. Multiple barriers to greater use were reported. Besides lack of time (55-62%), unfamiliarity with the recommendations, scarcity of evidence supporting the impact of recommendations on outcomes, insufficient training/experience in chronic GVHD management and inaccessibility of subspecialists were also endorsed. Systemic corticosteroids were reported to be the most effective treatment for chronic GVHD, but many others were perceived to have moderate or great success. Therapeutic management of steroid-refractory chronic GVHD was identified as the highest priority for research. PMID:23955633

  4. 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)

    Bhm, 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 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 outperformed by anthropogenic climate change.

  5. 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

  6. 28 CFR 16.135 - Exemptions of Executive Office for Organized Crime Drug Enforcement Task Forces Systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...); and (2) The Organized Crime Drug Enforcement Task Force Fusion Center and International Organized... Enforcement Task Force Fusion Center, the International Organized Crime Intelligence and Operations Center, or... Drug Enforcement Task Force Fusion Center, the International Organized Crime Intelligence...

  7. Force distribution analysis of mechanochemically reactive dimethylcyclobutene.

    PubMed

    Li, Wenjin; Edwards, Scott A; Lu, Lanyuan; Kubar, Tomas; Patil, Sandeep P; Grubmüller, Helmut; Groenhof, Gerrit; Gräter, Frauke

    2013-08-26

    Internal molecular forces can guide chemical reactions, yet are not straightforwardly accessible within a quantum mechanical description of the reacting molecules. Here, we present a force-matching force distribution analysis (FM-FDA) to analyze internal forces in molecules. We simulated the ring opening of trans-3,4-dimethylcyclobutene (tDCB) with on-the-fly semiempirical molecular dynamics. The self-consistent density functional tight binding (SCC-DFTB) method accurately described the force-dependent ring-opening kinetics of tDCB, showing quantitative agreement with both experimental and computational data at higher levels. Mechanical force was applied in two different ways, namely, externally by a constant pulling force and internally by embedding tDCB within a strained macrocycle-containing stiff stilbene. We analyzed the distribution of tDCB internal forces in the two different cases by FM-FDA and found that external force gave rise to a symmetric force distribution in the cyclobutene ring, which also scaled linearly with the external force, indicating that the force distribution was uniquely determined by the symmetric architecture of tDCB. In contrast, internal forces due to stiff stilbene resulted in an asymmetric force distribution within tDCB, which indicated a different geometry of force application and supported the important role of linkers in the mechanochemical reactivity of tDCB. In addition, three coordinates were identified through which the distributed forces contributed most to rate acceleration. These coordinates are mostly parallel to the coordinate connecting the two CH3 termini of tDCB. Our results confirm previous observations that the linker outside of the reactive moiety, such as a stretched polymer or a macrocycle, affects its mechanochemical reactivity. We expect FM-FDA to be of wide use to understand and quantitatively predict mechanochemical reactivity, including the challenging cases of systems within strained macrocycles. PMID:23843171

  8. Consensus criteria for sensitive detection of minimal neuroblastoma cells in bone marrow, blood and stem cell preparations by immunocytology and QRT-PCR: recommendations by the International Neuroblastoma Risk Group Task Force.

    PubMed

    Beiske, K; Burchill, S A; Cheung, I Y; Hiyama, E; Seeger, R C; Cohn, S L; Pearson, A D J; Matthay, K K

    2009-05-19

    Disseminating disease is a predictive and prognostic indicator of poor outcome in children with neuroblastoma. Its accurate and sensitive assessment can facilitate optimal treatment decisions. The International Neuroblastoma Risk Group (INRG) Task Force has defined standardised methods for the determination of minimal disease (MD) by immunocytology (IC) and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) using disialoganglioside G(D2) and tyrosine hydroxylase mRNA respectively. The INRG standard operating procedures (SOPs) define methods for collecting, processing and evaluating bone marrow (BM), peripheral blood (PB) and peripheral blood stem cell harvest by IC and QRT-PCR. Sampling PB and BM is recommended at diagnosis, before and after myeloablative therapy and at the end of treatment. Peripheral blood stem cell products should be analysed at the time of harvest. Performing MD detection according to INRG SOPs will enable laboratories throughout the world to compare their results and thus facilitate quality-controlled multi-centre prospective trials to assess the clinical significance of MD and minimal residual disease in heterogeneous patient groups. PMID:19401690

  9. Consensus criteria for sensitive detection of minimal neuroblastoma cells in bone marrow, blood and stem cell preparations by immunocytology and QRT-PCR: recommendations by the International Neuroblastoma Risk Group Task Force

    PubMed Central

    Beiske, K; Burchill, S A; Cheung, I Y; Hiyama, E; Seeger, R C; Cohn, S L; Pearson, A D J; Matthay, K K

    2009-01-01

    Disseminating disease is a predictive and prognostic indicator of poor outcome in children with neuroblastoma. Its accurate and sensitive assessment can facilitate optimal treatment decisions. The International Neuroblastoma Risk Group (INRG) Task Force has defined standardised methods for the determination of minimal disease (MD) by immunocytology (IC) and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) using disialoganglioside GD2 and tyrosine hydroxylase mRNA respectively. The INRG standard operating procedures (SOPs) define methods for collecting, processing and evaluating bone marrow (BM), peripheral blood (PB) and peripheral blood stem cell harvest by IC and QRT-PCR. Sampling PB and BM is recommended at diagnosis, before and after myeloablative therapy and at the end of treatment. Peripheral blood stem cell products should be analysed at the time of harvest. Performing MD detection according to INRG SOPs will enable laboratories throughout the world to compare their results and thus facilitate quality-controlled multi-centre prospective trials to assess the clinical significance of MD and minimal residual disease in heterogeneous patient groups. PMID:19401690

  10. 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.

  11. 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

  12. Neurology and international organizations

    PubMed Central

    2013-01-01

    A growing number of international stakeholders are engaged with neurologic diseases. This article provides a brief overview of important international stakeholders in the practice of neurology, including global disease-specific programs, United Nations agencies, governmental agencies with international influence, nongovernmental organizations, international professional organizations, large private donors, private–public partnerships, commercial interests, armed forces, and universities and colleges. The continued engagement of neurologists is essential for the growing number of international organizations that can and should incorporate neurologic disease into their global agendas. PMID:23877795

  13. 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).

  14. Contact sensing from force measurements

    NASA Technical Reports Server (NTRS)

    Bicchi, Antonio; Salisbury, J. K.; Brock, David L.

    1993-01-01

    This article addresses contact sensing (i.e., the problem of resolving the location of a contact, the force at the interface, and the moment about the contact normals). Called 'intrinsic' contact sensing for the use of internal force and torque measurements, this method allows for practical devices that provide simple, relevant contact information in practical robotic applications. Such sensors have been used in conjunction with robot hands to identify objects, determine surface friction, detect slip, augment grasp stability, measure object mass, probe surfaces, and control collision and for a variety of other useful tasks. This article describes the theoretical basis for their operation and provides a framework for future device design.

  15. 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

  16. 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

  17. 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

  18. 32 CFR 536.104 - Current agreements in force.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Current agreements in force. 536.104 Section 536... CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.104 Current agreements in force. Current listings of known agreements in force are also posted on the USARCS Web...

  19. 32 CFR 536.104 - Current agreements in force.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Current agreements in force. 536.104 Section 536... CLAIMS AGAINST THE UNITED STATES Claims Cognizable Under International Agreements § 536.104 Current agreements in force. Current listings of known agreements in force are also posted on the USARCS Web...

  20. Air Force brush seal programs

    NASA Technical Reports Server (NTRS)

    Dowler, Connie

    1993-01-01

    Aggressive pursuit of increased performance in gas turbine engines is driving the thermodynamic cycle to higher pressure ratios, bypass ratios, and turbine inlet temperatures. As these parameters increase, internal air system and resultant thermodynamic cycle losses increase. This conflict of reducing internal airflows while increasing thermodynamic efficiency and performance is putting more emphasis on improvements to the internal flow system. One improvement that has been and continues to be pursued by the Air Force for both man-rated and expendable turbine engine applications is the brush seal. This presentation briefly describes both past and current brush seal research and development programs and gives a summary of demonstrator and developmental engine testing of brush seals.

  1. 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.

  2. 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…

  3. Forces in general relativity

    NASA Astrophysics Data System (ADS)

    Ridgely, Charles T.

    2010-07-01

    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 by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.

  4. 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)

  5. 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.

  6. Microprocessor controlled force actuator

    NASA Technical Reports Server (NTRS)

    Zimmerman, D. C.; Inman, D. J.; Horner, G. C.

    1986-01-01

    The mechanical and electrical design of a prototype force actuator for vibration control of large space structures (LSS) is described. The force actuator is an electromagnetic system that produces a force by reacting against a proof-mass. The actuator has two colocated sensors, a digital microcontroller, and a power amplifier. The total weight of actuator is .998 kg. The actuator has a steady state force output of approximately 2.75 N from approximately 2 Hz to well beyond 1000 Hz.

  7. 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.

  8. 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…

  9. 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

  10. 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.

  11. 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…

  12. 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.

  13. 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 as land use change and heavy regional concentrations of BC aerosols, include more specific regional characteristics. We suggest that anthropogenic tropospheric O3 and the BC snow albedo effect contribute substantially to rapid warming and sea ice loss in the Arctic. As a complement to a priori forcings, such as Fi, Fa, and Fs, we tabulate the a posteriori effective forcing, Fe, which is the product of the forcing and its efficacy. Fe requires calculation of the climate response and introduces greater model dependence, but once it is calculated for a given amount of a forcing agent it provides a good prediction of the response to other forcing amounts.

  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. 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

  16. 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 24hours. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. 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

  5. Glenohumeral contact forces.

    PubMed

    Anglin, C; Wyss, U P; Pichora, D R

    2000-01-01

    Glenohumeral contact forces have only been calculated previously either for simple abduction or for athletic activities. The objective of this study was to determine the glenohumeral contact forces for tasks which are demanding of the shoulder but which would commonly be performed by older people. The functional tasks chosen were using the arms to stand up from and sit down into a chair, walking with a cane, lifting a 5 kg box to shoulder height with both hands, and lifting a 10 kg suitcase. The trunk angles, arm angles and hand loads of six healthy subjects, average age 55 years, were recorded. This information was input into a biomechanical computer model which optimized the muscle force distribution by minimizing the sum of squared muscle stresses subject to constraints on the maximum muscle forces and maintaining the direction of the resultant force within the glenoid fossa. Average contact forces ranged from 1.3 to 2.4 times body weight (930-1720 N), the highest force being for lifting a suitcase. This latter value would be even higher if lifting either a greater load or to a greater height. Thus, contact forces at the shoulder should not be underestimated. This study provides functionally relevant contact forces which can be used for mechanical testing or finite element modelling of shoulder prostheses. PMID:11201411

  6. 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 Advisory Group (SMPAG), NASA is placing an ever greater emphasis on sharing information among members and working to avoid duplication of effort for the betterment of all humanity. International cooperation at NASA takes many forms. In some cases NASA leads, while in other cases it follows the lead of our many international partners, all in the name of obtaining the best science. In many cases, truly stellar partnerships emerge. In a few cases, the partnership is ended before it can flourish. But in all cases, the partners are learning to work more closely together so that in the future, our partnerships will yield ever better results.

  7. 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

  8. 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…

  9. 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 or an El Nino.

  10. 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.

  11. 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…

  12. 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.

  13. HRP ForceShoe Evaluation - Duration: 97 seconds.

    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...

  14. Ponderomotive Forces in Cosmos

    NASA Astrophysics Data System (ADS)

    Lundin, R.; Guglielmi, A.

    2006-12-01

    This review is devoted to ponderomotive forces and their importance for the acceleration of charged particles by electromagnetic waves in space plasmas. Ponderomotive forces constitute time-averaged nonlinear forces acting on a media in the presence of oscillating electromagnetic fields. Ponderomotive forces represent a useful analytical tool to describe plasma acceleration. Oscillating electromagnetic fields are also related with dissipative processes, such as heating of particles. Dissipative processes are, however, left outside these discussions. The focus will be entirely on the (conservative) ponderomotive forces acting in space plasmas. The review consists of seven sections. In Section 1, we explain the rational for using the auxiliary ponderomotive forces instead of the fundamental Lorentz force for the study of particle motions in oscillating fields. In Section 2, we present the Abraham, Miller, Lundin-Hultqvist and Barlow ponderomotive forces, and the Bolotovsky-Serov ponderomotive drift. The hydrodynamic, quasi-hydrodynamic, and ‘`test-particle’' approaches are used for the study of ponderomotive wave-particle interaction. The problems of self-consistency and regularization are discussed in Section 3. The model of static balance of forces (Section 4) exemplifies the interplay between thermal, gravitational and ponderomotive forces, but it also introduces a set of useful definitions, dimensionless parameters, etc. We analyze the Alfvén and ion cyclotron waves in static limit with emphasis on the specific distinction between traveling and standing waves. Particular attention has been given to the impact of traveling Alfvén waves on the steady state anabatic wind that blows over the polar regions (Section~5). We demonstrate the existence of a wave-induced cold anabatic wind. We also show that, at a critical point, the ponderomotive acceleration of the wind is a factor of 3 greater than the thermal acceleration. Section 6 demonstrates various manifestations of ponderomotive forces in the Earth's magnetosphere, for instance the ionospheric plasma acceleration and outflow. The polar wind and the auroral density cavities are considered in relation to results from the Freja and Viking satellites. The high-altitude energization and escape of ions is discussed. The ponderomotive anharmonicity of standing Alfvén waves is analyzed from ground based ULF wave measurements. The complexity of the many challenging problems related with plasma processes near the magnetospheric boundaries is discussed in the light of recent Cluster observations. At the end of Section 6, we consider the application of ponderomotive forces to the diversity of phenomena on the Sun, in the interstellar environment, on newborn stars, pulsars and active galaxies. We emphasize the role of forcing of magnetized plasmas in general and ponderomotive forcing in particular, presenting some simple conceivable scenarios for massive outflow and jets from astrophysical objects.

  15. International migration, international relations and foreign policy.

    PubMed

    Mitchell, C

    1989-01-01

    Recent literature on migration, international relations, and foreign policy is reviewed in this article, stressing applications of global systems paradigms, studies of state entry and exit rules, and anatomies of domestic policy-setting processes on migration. After a concise assessment of the contemporary theory of global political economy, the paper argues for seeking mid-range generalizations on the international relations of migration. It also suggests that analysis begin with the policy-setting processes of the state. Especially through the use of comparative perspectives available from domestic policy making studies and from the field of international comparative public policy, this approach offers the opportunity to fix empirically the political roles of transnational social forces, which often present themselves as participants in domestic policy contests. Promising future directions in the study of state-to-state relations are also evaluated, with the anticipation that verifying regional or other intermediate patterns of world migration politics may contribute to more general theories of international political economy. PMID:12282800

  16. Forces exerted during microneurosurgery: a cadaver study

    PubMed Central

    Marcus, Hani J; Zareinia, Kourosh; Gan, Liu Shi; Yang, Fang Wei; Lama, Sanju; Yang, Guang-Zhong; Sutherland, Garnette R

    2014-01-01

    Background A prerequisite for the successful design and use of robots in neurosurgery is knowledge of the forces exerted by surgeons during neurosurgical procedures. The aim of the present cadaver study was to measure the surgical instrument forces exerted during microneurosurgery. Methods An experimental apparatus was set up consisting of a platform for human cadaver brains, a Leica microscope to provide illumination and magnification, and a Quanser 6 Degrees-Of-Freedom Telepresence System for tissue manipulation and force measurements. Results The measured forces varied significantly depending on the region of the brain (P = 0.016) and the maneuver performed (P < 0.0001). Moreover, blunt arachnoid dissection was associated with greater force exertion than sharp dissection (0.22 N vs. 0.03 N; P = 0.001). Conclusions The forces necessary to manipulate brain tissue were surprisingly low and varied depending on the anatomical structure being manipulated, and the maneuver performed. Knowledge of such forces could well increase the safety of microsurgery. © 2014 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery published by John Wiley & Sons, Ltd. PMID:24431265

  17. 22 CFR 126.12 - Continuation in force.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Continuation in force. 126.12 Section 126.12 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.12 Continuation in force. All determinations, authorizations, licenses, approvals...

  18. 22 CFR 126.12 - Continuation in force.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Continuation in force. 126.12 Section 126.12 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.12 Continuation in force. All determinations, authorizations, licenses, approvals...

  19. 22 CFR 126.12 - Continuation in force.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Continuation in force. 126.12 Section 126.12 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.12 Continuation in force. All determinations, authorizations, licenses, approvals...

  20. 22 CFR 126.12 - Continuation in force.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Continuation in force. 126.12 Section 126.12 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.12 Continuation in force. All determinations, authorizations, licenses, approvals of contracts and agreements and other action...

  1. 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.

  2. 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.

  3. Modeling of forces on large MEMS

    SciTech Connect

    Saif, M.T.A.; MacDonald, N.C.

    1995-12-31

    Considerable progress has so far been achieved in the fabrication of Micro Electro Mechanical (MEM) structures made of Single Crystal Silicon. However, a detailed mechanistic study of the forces applied on MEM structures during and after fabrication is far from completion. Such studies are essential for the design of large (few mm) MEMS made of micron size features and gaps, because they have large surface to volume ratio. The surface and interface forces play a major role in their overall performance. We model the major forces applied on the MEM structures. They are: (1) Internal forces due to intrinsic strains of thin films and mismatch of the materials thermal coefficients of expansion. Such forces may deform large MEMS and render them non-planar with limited usefulness. We study the internal stresses and the corresponding deformations of large MEMS fabricated by the SCREAM (Single Crystal Reactive Ion Etching and Metallization) process developed at Cornell. We show that large planar structures can indeed be fabricated by the process by carefully designing the cross section of beams that form the structures. The study is verified by experiments.

  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. 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)

  6. The Changing Work Force.

    ERIC Educational Resources Information Center

    Koehn, Hank E.

    1982-01-01

    Describes changes in employee characteristics and attitudes. Discusses changes in life-styles and the need to cope with change. Notes implications for education and suggests the development of new alternatives for the changing work force. (RC)

  7. 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

  8. 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. In terms of the forced variance, we find that the interactive ensemble increases this variance relative to the control.

  9. 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.

  10. 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.

  11. The Missing Climate Forcing

    NASA Astrophysics Data System (ADS)

    Hansen, J.; Sato, M.; Lacis, A.; Ruedy, R.

    1997-02-01

    Observed climate change is consistent with radiative forcings on several time scales for which the dominant forcings are known, ranging from the few years after a large volcanic eruption to glacial-to-interglacial changes. In the period with most detailed data, 1979 to the present, climate observations contain clear signatures of both natural and anthropogenic forcings. But in the full period since the industrial revolution began, global warming is only about half of that expected due to the principal forcing, increasing greenhouse gases. The direct radiative effect of anthropogenic aerosols contributes only little towards resolving this discrepancy. Unforced climate variability is an unlikely explanation. We argue on the basis of several lines of indirect evidence that aerosol effects on clouds have caused a large negative forcing, at least -1 Wm-2, which has substantially offset greenhouse warming. The tasks of observing this forcing and determining the microphysical mechanisms at its basis are exceptionally difficult, but they are essential for the prognosis of future climate change.

  12. The missing climate forcing

    PubMed Central

    Hansen, J.; Sato, M.; Lacis, A.; Ruedy, R.

    1997-01-01

    Observed climate change is consistent with radiative forcings on several time-scales for which the dominant forcings are known, ranging from the few years after a large volcanic eruption to glacial-to-interglacial changes. In the period with most detailed data, 1979 to the present, climate observations contain clear signatures of both natural and anthropogenic forcings. But in the full period since the industrial revolution began, global warming is only about half of that expected due to the principal forcing, increasing greenhouse gases. The direct radiative effect of anthropogenic aerosols contributes only little towards resolving this discrepancy. Unforced climate variability is an unlikely explanation. We argue on the basis of several lines of indirect evidence that aerosol effects on clouds have caused a large negative forcing, at least -1 Wm-2, which has substantially offset greenhouse warming. The tasks of observing this forcing and determining the microphysical mechanisms at its basis are exceptionally difficult, but they are essential for the prognosis of future climate change.

  13. International programs

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Brief summaries are given of NASA's participation in international space programs. This participation can be categorized in five principal areas: manned space flight, space sciences, space applications, ground support of space operations, and cooperative international aeronautics research. All projects are carried out on a cooperative or reimbursable basis.

  14. International Indirection.

    ERIC Educational Resources Information Center

    Malinconico, S. Michael

    1979-01-01

    Criticizes the Library of Congress' manner of representing the United States in international attempts to develop universal bibliographic control. Direct involvement by American libraries in international activities is urged, in order that actions taken be decided upon in a democratic fashion. (SW)

  15. 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.

  16. 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

  17. Stability of Trilateral Forces: III, Large Unsymmetric Forces

    SciTech Connect

    Canavan, G.H.

    1998-09-18

    For large unsymmetric forces, at few weapons permissile all forces are reserved, costs are constant, and configurations are stable. At many weapons permissile, no weapons are reserved, and stability degrades. For small unequal forces, the equal sides ignore the smaller forces and deter each other as in bilinear engagements. For large unequal forces, the equal sides ignore each other, commit all forces to the unequal side, and stability indices approach those observed for large triads.

  18. Governing International Education in Australia

    ERIC Educational Resources Information Center

    Sidhu, Ravinder

    2004-01-01

    This paper uses the international education sector in Australia as a case study to argue against understanding globalization as an exogenous force. It introduces the notion of globalization as a governmentality and discusses alternative interpretations which take into account notions of subjectivity, positionality and space/time. The paper…

  19. Polynomial force approximations and multifrequency atomic force microscopy

    PubMed Central

    Forchheimer, Daniel; Tholén, Erik A; Haviland, David B

    2013-01-01

    Summary We present polynomial force reconstruction from experimental intermodulation atomic force microscopy (ImAFM) data. We study the tip–surface force during a slow surface approach and compare the results with amplitude-dependence force spectroscopy (ADFS). Based on polynomial force reconstruction we generate high-resolution surface-property maps of polymer blend samples. The polynomial method is described as a special example of a more general approximative force reconstruction, where the aim is to determine model parameters that best approximate the measured force spectrum. This approximative approach is not limited to spectral data, and we demonstrate how it can be adapted to a force quadrature picture. PMID:23844340

  20. Future trends in international migration to Europe.

    PubMed

    Verhaeren, R

    1993-01-01

    The author discusses future trends in international migration to Europe, with a focus on the impact of the economic situation on labor force needs and resources. Aspects considered include changes in foreign direct investments, changes in the size of the European labor market, and the potential emigration of the labor force in underdeveloped countries. PMID:12287572

  1. 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)

  2. 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.

  3. 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.

  4. Trends of measured climate forcing agents.

    PubMed

    Hansen, J E; Sato, M

    2001-12-18

    The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/m(2) per century. This growth rate has since declined to approximately 3 W/m(2) 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 2 W/m(2) 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 CO(2) 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 degrees C per decade will occur over the next several decades. PMID:11752424

  5. 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

  6. 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.

  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. 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

  9. 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

  10. 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.

  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. Optical force stamping lithography

    PubMed Central

    Nedev, Spas; Urban, Alexander S.; Lutich, Andrey A.; Feldmann, Jochen

    2013-01-01

    Here we introduce a new paradigm of far-field optical lithography, optical force stamping lithography. The approach employs optical forces exerted by a spatially modulated light field on colloidal nanoparticles to rapidly stamp large arbitrary patterns comprised of single nanoparticles onto a substrate with a single-nanoparticle positioning accuracy well beyond the diffraction limit. Because the process is all-optical, the stamping pattern can be changed almost instantly and there is no constraint on the type of nanoparticle or substrates used. PMID:21992538

  14. [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

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. 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.

  20. 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.…

  1. 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.

  2. 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.

  3. Optically induced 'negative forces'

    NASA Astrophysics Data System (ADS)

    Dogariu, Aristide; Sukhov, Sergey; Sáenz, José

    2013-01-01

    Attracting objects with optical beams may seem like science fiction, but various schemes already do this, albeit with some caveats and limitations. The most recent progress in this emerging field is reviewed, with particular emphasis on manipulation of small objects by optically induced 'negative forces'.

  4. 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 antiquarks in that event.

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Amplification of actin polymerization forces.

    PubMed

    Dmitrieff, Serge; Nédélec, François

    2016-03-28

    The actin cytoskeleton drives many essential processes in vivo, using molecular motors and actin assembly as force generators. We discuss here the propagation of forces caused by actin polymerization, highlighting simple configurations where the force developed by the network can exceed the sum of the polymerization forces from all filaments. PMID:27002174

  11. 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.

  12. 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,...

  13. 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...

  14. 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,...

  15. 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...

  16. 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,...

  17. Forced response of a laminar shock-induced separation bubble

    NASA Astrophysics Data System (ADS)

    Sansica, A.; Sandham, N. D.; Hu, Z.

    2014-09-01

    The source of unsteadiness in shock-wave/boundary-layer interactions is currently disputed. This paper considers a two-dimensional separation bubble induced by an oblique shock wave interacting with a laminar boundary layer at a free-stream Mach number of 1.5. The global response of the separated region to white noise forcing is analyzed for different interaction strengths, which generate small and large separation bubbles. Forcing location and amplitude effects have been examined. For both interaction strengths and for forcing both upstream and inside the bubble, the wall-pressure spectra downstream of the separation show a high-frequency peak that is demonstrated to be a Kelvin-Helmholtz instability. A low-frequency response at the separation point is also found when the separation bubble is only forced internally, therefore with a disturbance-free upstream boundary layer. For low-amplitude internal forcing, the low-frequency response at the separation point and downstream of the bubble is linear. However, when forced upstream the low-frequency unsteadiness of the large separation bubble is found to be driven by nonlinearities coming from the downstream shedding. The same nonlinear behavior is found when the separation bubble is internally forced over a narrow band around the shedding frequency, without low-frequency disturbances. This analysis for a laminar interaction is used to interpret the low-frequency unsteadiness found at the foot of the shock of turbulent interactions. Here, the low-frequency unsteadiness occurs in the absence of upstream disturbances and a linear relationship is found between the internal forcing and the response near the separation point. When low-frequencies are not present in the forcing they are generated from weak nonlinearities of the shear-layer instability modes.

  18. 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.

  19. Internal shim

    SciTech Connect

    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.

  20. 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 marry the die-specific Force Modulator technology with stamping presses in the form of a press cushion. This system would be designed to operate the binder ring for multiple parts, thus cutting the per-die cost of the technology. This study reports the results of technology field application. This project produced the following conclusions: (1) The Force Modulator system is capable of operating at very high tempos in the stamping environment; (2) The company can generate substantial, controlled holding tonnage (binder ring pressure) necessary to hold high strength steel parts for proper formation during draw operations; (3) A single system can be designed to operate with a family of parts, thus significantly reducing the per-die cost of a FM system; (4) High strength steel parts made with these systems appear to show significant quality improvements; (5) The amounts of steel required to make these parts is typically less than the amounts required with traditional blank-holding technologies; and (6) This technology will aid in the use of higher strength steels in auto and truck production, thus reducing weight and improving fuel efficiency.

  1. 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

  2. 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 an approximate equation for the vorticity correlation function that is then solved perturbatively. The Reynolds stress of the pertubative solution can then be expressed as a function of the mean-flow and its y-derivatives. In particular, it is shown that as long as the forcing breaks mirror-symmetry, the Reynolds stress has a wave-like term, as a result of which the mean-flow is governed by a dispersive wave equation. In a separate study, Reynolds stress induced by an anisotropically forced unbounded Couette flow with uniform shear gamma, on a beta-plane, is calculated in conjunction with the eddy diffusivity of a co-evolving passive tracer. The flow is damped by linear drag on a time scale mu--1. The stochastic forcing is controlled by a parameter alpha, that characterizes whether eddies are elongated along the zonal direction (alpha < 0), the meridional direction (alpha > 0) or are isotropic (alpha = 0). The Reynolds stress varies linearly with alpha and non-linearly and non-monotonically with gamma; but the Reynolds stress is independent of beta. For positive values of alpha, the Reynolds stress displays an "anti-frictional" effect (energy is transferred from the eddies to the mean flow) and a frictional effect for negative values of alpha. With gamma = beta =0, the meridional tracer eddy diffusivity is v'2/(2mu), where v' is the meridional eddy velocity. In general, beta and gamma suppress the diffusivity below v'2/(2mu).

  3. Hydrofoil force balance

    NASA Astrophysics Data System (ADS)

    Lefebvre, Paul J.; Barker, William P.

    1994-07-01

    The present invention relates to a measuring device for measuring a component of a force acting on a test body, such as a hydrofoil, positioned within a testing apparatus. The measuring device has a test body formed by a foil shaped center section and two adjacent end sections. Each end section is joined to the center section by a flexure member having sufficient stiffness so that there is negligible relative motion between the center section and the end sections as a fluid medium flows past the center section. At least one strain gauge is mounted to at least one flexure member to measure the forces acting on the center section. A method for measuring the load on a test body is also described.

  4. 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.

  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. Ultrasonic Force Microscopies

    NASA Astrophysics Data System (ADS)

    Kolosov, Oleg; Briggs, Andrew

    Ultrasonic Force Microscopy, or UFM, allows combination of two apparently mutually exclusive requirements for the nanomechanical probe—high stiffness for the efficient indentation and high mechanical compliance that brings force sensitivity. Somewhat inventively, UFM allows to combine these two virtues in the same cantilever by using indention of the sample at high frequency, when cantilever is very rigid, but detecting the result of this indention at much lower frequency. That is made possible due to the extreme nonlinearity of the nanoscale tip-surface junction force-distance dependence, that acts as "mechanical diode" detecting ultrasound in AFM. After introducing UFM principles, we discuss features of experimental UFM implementation, and the theory of contrast in this mode, progressing to quantitative measurements of contact stiffness. A variety of UFM applications ranging from semiconductor quantum nanostructures, graphene, very large scale integrated circuits, and reinforced ceramics to polymer composites and biological materials is presented via comprehensive imaging gallery accompanied by the guidance for the optimal UFM measurements of these materials. We also address effects of adhesion and topography on the elasticity imaging and the approaches for reducing artifacts connected with these effects. This is complemented by another extremely useful feature of UFM—ultrasound induced superlubricity that allows damage free imaging of materials ranging from stiff solid state devices and graphene to biological materials. Finally, we proceed to the exploration of time-resolved nanoscale phenomena using nonlinear mixing of multiple vibration frequencies in ultrasonic AFM—Heterodyne Force Microscopy, or HFM, that also include mixing of ultrasonic vibration with other periodic physical excitations, eg. electrical, photothermal, etc. Significant section of the chapter analyzes the ability of UFM and HFM to detect subsurface mechanical inhomogeneities, as well as describes related sample preparation methods on the example of subsurface imaging of nanostructures and iii-v quantum dots.

  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. The task force process

    SciTech Connect

    Applegate, J.S.

    1995-01-31

    This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several {open_quotes}big picture{close_quotes} issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald.

  9. ``Force,'' ontology, and language

    NASA Astrophysics Data System (ADS)

    Brookes, David T.; Etkina, Eugenia

    2009-06-01

    We introduce a linguistic framework through which one can interpret systematically students’ understanding of and reasoning about force and motion. Some researchers have suggested that students have robust misconceptions or alternative frameworks grounded in everyday experience. Others have pointed out the inconsistency of students’ responses and presented a phenomenological explanation for what is observed, namely, knowledge in pieces. We wish to present a view that builds on and unifies aspects of this prior research. Our argument is that many students’ difficulties with force and motion are primarily due to a combination of linguistic and ontological difficulties. It is possible that students are primarily engaged in trying to define and categorize the meaning of the term “force” as spoken about by physicists. We found that this process of negotiation of meaning is remarkably similar to that engaged in by physicists in history. In this paper we will describe a study of the historical record that reveals an analogous process of meaning negotiation, spanning multiple centuries. Using methods from cognitive linguistics and systemic functional grammar, we will present an analysis of the force and motion literature, focusing on prior studies with interview data. We will then discuss the implications of our findings for physics instruction.

  10. Measurement and stochastic modeling of kidney puncture forces.

    PubMed

    van Gerwen, D J; Dankelman, J; van den Dobbelsteen, J J

    2014-03-01

    The development of needle insertion robots and training simulators requires knowledge of the forces that arise when a needle is inserted into soft-tissue. The present study aims to construct stochastic models of the force required to puncture a kidney using a trocar needle, based on measurements. To this end, a total of sixty insertions were performed into porcine kidneys (ex vivo), at constant speed, using a linear motion stage. Axial force was measured at the needle hub and an ultrasound probe moved with the needle to enable identification of anatomical structures. Two force peaks were observed for each tissue layer punctured, one caused by the tip and one by the edge of the cannula. Based on ultrasound data these double-peaks were classified into four groups, related to kidney capsule and internal structures. Group size varied from 7 to 55 double-peaks. Force peaks in each group were evaluated in terms of peak force and drop in force for both tip and cannula, and stochastic models were constructed that describe the multivariate distribution of these metrics. Peak forces in the capsule and internal structures ranged up to 2 N and 8 N, respectively. The resulting models can be used to simulate kidney puncture events in a variety of applications. PMID:24129753

  11. Coordination of Contact Forces During Multifinger Static Prehension

    PubMed Central

    Martin, Joel R.; Latash, Mark L.

    2011-01-01

    This study investigated the effects of modifying contact finger forces in one direction—normal or tangential—on the entire set of the contact forces, while statically holding an object. Subjects grasped a handle instrumented with finger force-moment sensors, maintained it at rest in the air, and then slowly: (1) increased the grasping force, (2) tried to spread fingers apart, and (3) tried to squeeze fingers together. Analysis was mostly performed at the virtual finger (VF) level (the VF is an imaginable finger that generates the same force and moment as the four fingers combined). For all three tasks there were statistically significant changes in the VF normal and tangential forces. For finger spreading/squeezing the tangential force neutral point was located between the index and middle fingers. We conclude that the internal forces are regulated as a whole, including adjustments in both normal and tangential force, instead of only a subset of forces (normal or tangential). The effects of such factors as EFFORT and TORQUE were additive; their interaction was not statistically significant, thus supporting the principle of superposition in human prehension. PMID:21576716

  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 Reports.

    ERIC Educational Resources Information Center

    Anderson, Nancy D.; And Others

    1994-01-01

    Three reports discuss the International Federation of Library Associations and Institutions; the Frankfurt Book Fair, focusing on electronics; and Canadian library trends, including resource sharing, technology projects, information policy, censorship, services for persons with disabilities, construction projects, and library education and…

  14. Cooperating Internationally.

    ERIC Educational Resources Information Center

    Anderson, Wayne

    1999-01-01

    A number of college and university consortia have embarked on international educational cooperation ventures, providing valuable experiences and benefits for faculty, students, alumni, and the community. For these programs to be effective, they must have high-level institutional support, equal opportunities to participate, effective marketing and…

  15. 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…

  16. 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

  17. 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 should be brought to industrializing countries by a comprehensive consultative program sponsored by the United States and other countries that are willing to share the burden. Occupational health and safety program development is tied to the economic success of the industrializing country and its industries. Only after the development of a successful legal and economic system in an industrializing country is it possible to incorporate a successful program of occupational health and safety. PMID:12971685

  18. Force reflection with compliance control

    NASA Astrophysics Data System (ADS)

    Kim, Won S.

    1993-08-01

    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.

  19. 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.

  20. 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.

  1. 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;…

  2. Force transmission in epithelial tissues.

    PubMed

    Vasquez, Claudia G; Martin, Adam C

    2016-03-01

    In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells' decisions to divide, die, or differentiate. Forces are transmitted across epithelia because cells are mechanically linked through junctional complexes, and forces can propagate through the cell cytoplasm. Here, we review some of the molecular mechanisms responsible for force generation, with a specific focus on the actomyosin cortex and adherens junctions. We then discuss evidence for how these mechanisms promote cell shape changes and force transmission in tissues. Developmental Dynamics 245:361-371, 2016. 2016 Wiley Periodicals, Inc. PMID:26756938

  3. 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 of the efficacy of solar reductions by repeating the same calculation for different intantaneous changes in CO2 concentrations.

  4. 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…

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. [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 considered to attract population and 44.4% was in the 129 weakly expulsive municipios. 2.4% of the population was in the strongly expulsive municipios. Census data from 1970 and 1980 indicate that 60% of Puebla's emigrants during the 1970s went to the Mexico City area, with a considerable proportion of the remainder going to the states of Mexico or Veracruz. It is likely that some of the faster growing. A 1987 migration survey in the city of Puebla indicated that 25% of the population was not native and that about 1/3 of the migrants were from elsewhere in the state of Puebla. About equal proportions of inmigrants to the city were of rural origin or from other cities. PMID:12284141

  11. van der Waals Forces

    PubMed Central

    Ninham, B. W.; Parsegian, V. A.

    1970-01-01

    A practical method for examining and calculating van der Waals forces is derived from Lifshitz' theory. Rather than treat the total van der Waals energy as a sum of pairwise interactions between atoms, the Lifshitz theory treats component materials as continua in which there are electromagnetic fluctuations at all frequencies over the entire body. It is necessary in principle to use total macroscopic dielectric data from component substances to analyze the permitted fluctuations; in practice it is possible to use only partial information to perform satisfactory calculations. The biologically interesting case of lipid-water systems is considered in detail for illustration. The method gives good agreement with measured van der Waals energy of interaction across a lipid film. It appears that fluctuations at infrared frequencies and microwave frequencies are very important although these are usually ignored in preference to UV contributions. “Retardation effects” are such as to damp out high frequency fluctuation contributions; if interaction specificity is due to UV spectra, this will be revealed only at interactions across <200 angstrom (A). Dependence of van der Waals forces on material electric properties is discussed in terms of illustrative numerical calculations. PMID:5449915

  12. Environmental Crack Driving Force

    NASA Astrophysics Data System (ADS)

    Hall, M. M.

    2013-03-01

    The effect of environment on the crack driving force is considered, first by assuming quasistatic extension of a stationary crack and second, by use of stress corrosion cracking (SCC) crack growth rate models developed previously by this author and developed further here. A quasistatic thermodynamic energy balance approach, of the Griffith-Irwin type, is used to develop stationary crack threshold expressions, tilde{J}_c , which represent the conjoint mechanical and electrochemical conditions, below which stationary cracks are stable. Expressions for the electrochemical crack driving force (CDF) were derived using an analysis that is analogous to that used by Irwin to derive his "strain energy release rate," G, which Rice showed as being equivalent to his mechanical CDF, J. The derivations show that electrochemical CDFs both for active path dissolution (APD) and hydrogen embrittlement (HE) mechanisms of SCC are simply proportional to Tafel's electrochemical anodic and cathodic overpotentials, η a and η c, respectively. Phenomenological SCC models based on the kinetics of APD and HE crack growth are used to derive expressions for the kinetic threshold, J scc, below which crack growth cannot be sustained. These models show how independent mechanical and environmental CDFs may act together to drive SCC crack advance. Development of a user-friendly computational tool for calculating Tafel's overpotentials is advocated.

  13. 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

  14. 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

  15. Force reflecting hand controller

    NASA Astrophysics Data System (ADS)

    McAffee, Douglas A.; Snow, Edward R.; Townsend, William T.

    1993-03-01

    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.

  16. 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.

  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. 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.

  19. Force-Field Parameter Fitter

    SciTech Connect

    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.

  20. A model for neural control of gradation of muscle force.

    PubMed

    Tax, A A; Denier van der Gon, J J

    1991-01-01

    A mathematical muscle model is presented that relates neural control signals linearly to muscle force without violating important known physiological constraints, such as the size-principle (Henneman and Mendell 1981) and non-linear twitch summation (Burke et al. 1976). This linearity implies that the neural control signals (defined as a weighted sum of activities in a nerve bundle) can be interpreted as the internal representation of total muscle force. The model allows for different relative contributions from the two force-grading mechanisms, i.e. the recruitment of motor units and the modulation of their firing frequency. It can therefore be applied to a variety of (distal and proximal) muscles. Furthermore, it permits simple mechanisms for controlling muscle force, e.g. in superposed motor tasks. The model confirms our intuitive notion that a weighted sum of activities in a nerve bundle can directly represent an external controlled variable, which in this case is exerted muscle force. PMID:1932280

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Proximal arm kinematics affect grip force-load force coordination.

    PubMed

    Vermillion, Billy C; Lum, Peter S; Lee, Sang Wook

    2015-10-01

    During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P < 0.001). Biomechanical coupling between extrinsic hand muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio). PMID:26289460

  7. Resonant forcing and instabilities of inertial waves

    NASA Astrophysics Data System (ADS)

    Cebron, D.; Le Bars, M.

    2012-12-01

    The flows in fluid layers of planets and moons are of major interest because they imply first order consequences for their internal dynamics and orbital evolutions. Indeed, internal flows create torques on solid layers and induce energy dissipation. Moreover, internal flows are directly responsible for the generation of magnetic fields, either by induction of an existing background magnetic field or by excitation of a self-sustained dynamo. Finally, planetary heat fluxes are also directly linked to flows in fluid layers, which can act as thermal blankets for stably stratified configurations, or as efficient heat flux conveyers in the case of convective flows. Planetary fluid layers are subject to body rotation, which implies that inertial waves can propagate through them. Usually damped by viscosity, these waves can, however, be excited by longitudinal libration, precession, and tides, which are harmonic mechanical forcings of azimuthal periodicity m=0, 1, and 2, respectively. In previous studies, it has been shown that the dynamics of a fluid layer is completely modified when the forcing resonates with an inertial wave. In addition to these direct forcings, inertial waves can also form triadic resonances, leading to parametric inertial instabilities. For instance, the so-called precssional inertial instability can be excited by precession, and the elliptical instability can be excited by tides in non-synchronized bodies and by librations in synchronized ones. These different inertial mechanisms are discussed in the framework of the Earth's liquid core. In particular, we take the presence of the solid inner core into account in our analysis, showing the possible strong influence of its motion on the flows driven by these inertial resonances. For instance, we show and quantify for the first time the possible excitation of an elliptical instability by an ellipsoidal inner core rotating or oscillating in a spherical surrounding liquid core. We also present some new inertial instabilities possibly directly excited by the solid inner core motions.

  8. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Combat zone compensation of members of the Armed Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Excluded from Gross Income § 1.112-1 Combat zone compensation...

  9. 26 CFR 1.112-1 - Combat zone compensation of members of the Armed Forces.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Combat zone compensation of members of the Armed Forces. 1.112-1 Section 1.112-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Excluded from Gross Income § 1.112-1 Combat zone compensation...

  10. The Air Force concentrating photovoltaic array program

    NASA Technical Reports Server (NTRS)

    Geis, Jack W.

    1987-01-01

    A summary is given of Air Force solar concentrator projects beginning with the Rockwell International study program in 1977. The Satellite Materials Hardening Programs (SMATH) explored and developed techniques for hardening planar solar cell array power systems to the combined nuclear and laser radiation threat environments. A portion of program dollars was devoted to developing a preliminary design for a hardened solar concentrator. The results of the Survivable Concentrating Photovoltaic Array (SCOPA) program, and the design, fabrication and flight qualification of a hardened concentrator panel 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. 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.

  13. Downhole force generator

    SciTech Connect

    Kilgore, M.D.

    1991-12-10

    This patent describes a well tool for generating and applying an upward axial force to an object at a subsurface location in a well flow conductor. It comprises body means, (i) an upper body member having a longitudinal bore extending therethrough and having means at its upper end for attachment to a handling string; (ii) pressure responsive means near the upper end of the upper body member for anchoring the same in the well flow conductor; (iii) piston means on the upper body member a spaced distance below the anchoring means; (iv) a lower body member having a longitudinal bore extending therethrough, and upper portion of the bore being enlarged and in which the piston means of the upper body member is reciprocable, the piston means providing in the cylinder means a power chamber and an exhaust chamber, including seal means and between the upper body member and the lower body member at both the upper and lower ends of the cylinder means.

  14. The NACA Test Force

    NASA Technical Reports Server (NTRS)

    1952-01-01

    The fleet of NACA test aircraft are assembled in front of the hangar at the High Speed Flight Station, (later renamed the Dryden Flight Research Center) in Edwards, California. The white aircraft in the foreground is a Douglas Aircraft D-558-2 Skyrocket. To its left and right are North American F-86 Sabre chase aircraft. Directly behind the D-558-2 is the P2B-1 Superfortress, (the Navy version of the Air Force B-29). Also known as the 'mothership,' the P2B-1 carried aloft the D-558-2 Skyrocket under its fuselage. Once reaching altitude, the D-558-2 was released from the 'mothership' after which the pilot ignited its onboard rocket engine.

  15. 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.

  16. Relativistic tidal forces

    SciTech Connect

    Nordtvedt, K.

    1983-01-15

    The post-Newtonian, relativistic (1/c/sup 2/) tidal force is calculated within the general PPN framework of all metric theories of gravity. There are no relativistic tides in general relativity, but they are generally nonzero in other metric theories of gravity, including scalar-tensor theories. In close binaries (GM/c/sup 2/Rroughly-equal10/sup -6/), such as the binary pulsar system PSR 1913+16, the relativistic tides can be orders of magnitude larger than Newtonian tides. In ''preferred frame'' theories of gravity in which the PPN coefficient ..cap alpha../sub 1/ is nonzero, the relativistic tidal field is not the gradient of a scalar potential, but includes also a circulating, nonconservative field in a body.

  17. 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

  18. 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.

    2011-02-01

    Climatic effects of short-lived climate forcers (SLCFs) differ from those of long-lived greenhouse gases, because they occur rapidly after emission and because they depend upon the region of emission. The distinctive temporal and spatial nature of these impacts is not captured by measures that rely on global averages or long time integrations. Here, we propose a simple measure, the Specific Forcing Pulse (SFP), to quantify climate warming or cooling by these pollutants, where we define "immediate" as occurring primarily within the first year after emission. SFP is the amount of energy added to or removed from a receptor region in the Earth-atmosphere system by a chemical species, per mass of emission in a source region. We limit the application of SFP to species that remain in the atmosphere for less than one year. Metrics used in policy discussions, such as total forcing or global warming potential, are easily derived from SFP. However, SFP conveys purely physical information without incurring the policy implications of choosing a time horizon for the global warming potential. Using one model (Community Atmosphere Model, or CAM), we calculate values of SFP for black carbon (BC) and organic matter (OM) emitted from 23 source-region combinations. Global SFP for both atmosphere and cryosphere impacts is divided among receptor latitudes. SFP is usually greater for open-burning emissions than for energy-related (fossil-fuel and biofuel) emissions because of the timing of emission. Global SFP for BC varies by about 45% for energy-related emissions from different regions. This variation would be larger except for compensating effects. When emitted aerosol has larger cryosphere forcing, it often has lower atmosphere forcing because of less deep convection and a shorter atmospheric lifetime. A single model result is insufficient to capture uncertainty. We develop a best estimate and uncertainties for SFP by combining forcing results from 12 additional models. We outline a framework for combining a large number of simple models with a smaller number of enhanced models that have greater complexity. Adjustments for black carbon internal mixing and for regional variability are discussed. Emitting regions with more deep convection have greater model diversity. Our best estimate of global-mean SFP is +1.03 0.52 GJ g-1 for direct atmosphere forcing of black carbon, +1.15 0.53 GJ g-1 for black carbon including direct and cryosphere forcing, and -0.064 (-0.02, -0.13) GJ g-1 for organic matter. These values depend on the region and timing of emission. The lowest OM:BC mass ratio required to produce a neutral effect on top-of-atmosphere direct forcing is 15:1 for any region. Any lower ratio results in positive direct forcing. However, important processes, particularly cloud changes that tend toward cooling, have not been included here. Global-average SFP for energy-related emissions can be converted to a 100-year GWP of about 740 370 for BC without snow forcing, and 830 440 with snow forcing. 100-year GWP for OM is -46 (-18, -92). Best estimates of atmospheric radiative impact (without snow forcing) by black and organic matter are +0.47 0.26 W m-2 and -0.17 (-0.07, -0.35) W m-2 for BC and OM, respectively, assuming total emission rates of 7.4 and 45 Tg yr-1. Anthropogenic forcing is +0.40 0.18 W m-2 and -0.13 (-0.05, -0.25) W m-2 for BC and OM, respectively, assuming anthropogenic emission rates of 6.3 and 32.6 Tg yr-1. Black carbon forcing is only 18% higher than that given by the Intergovernmental Panel on Climate Change (IPCC), although the value presented here includes enhanced absorption due to internal mixing.

  19. 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

  20. 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.

  1. Theory of rapid force spectroscopy

    NASA Astrophysics Data System (ADS)

    Bullerjahn, Jakob T.; Sturm, Sebastian; Kroy, Klaus

    2014-07-01

    In dynamic force spectroscopy, single (bio-)molecular bonds are actively broken to assess their range and strength. At low loading rates, the experimentally measured statistical distributions of rupture forces can be analysed using Kramers’ theory of spontaneous unbinding. The essentially deterministic unbinding events induced by the extreme forces employed to speed up full-scale molecular simulations have been interpreted in mechanical terms, instead. Here we start from a rigorous probabilistic model of bond dynamics to develop a unified systematic theory that provides exact closed-form expressions for the rupture force distributions and mean unbinding forces, for slow and fast loading protocols. Comparing them with Brownian dynamics simulations, we find them to work well also at intermediate pulling forces. This renders them an ideal companion to Bayesian methods of data analysis, yielding an accurate tool for analysing and comparing force spectroscopy data from a wide range of experiments and simulations.

  2. Theory of rapid force spectroscopy

    PubMed Central

    Bullerjahn, Jakob T.; Sturm, Sebastian; Kroy, Klaus

    2014-01-01

    In dynamic force spectroscopy, single (bio-)molecular bonds are actively broken to assess their range and strength. At low loading rates, the experimentally measured statistical distributions of rupture forces can be analysed using Kramers’ theory of spontaneous unbinding. The essentially deterministic unbinding events induced by the extreme forces employed to speed up full-scale molecular simulations have been interpreted in mechanical terms, instead. Here we start from a rigorous probabilistic model of bond dynamics to develop a unified systematic theory that provides exact closed-form expressions for the rupture force distributions and mean unbinding forces, for slow and fast loading protocols. Comparing them with Brownian dynamics simulations, we find them to work well also at intermediate pulling forces. This renders them an ideal companion to Bayesian methods of data analysis, yielding an accurate tool for analysing and comparing force spectroscopy data from a wide range of experiments and simulations. PMID:25079911

  3. 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.

  4. 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.

  5. Atomic force microscope cantilever calibration device for quantified force metrology at micro- or nano-scale regime: the nano force calibrator (NFC)

    NASA Astrophysics Data System (ADS)

    Kim, Min-Seok; Choi, Jae-Hyuk; Park, Yon-Kyu; Kim, Jong-Ho

    2006-10-01

    Motivated by emerging needs for accurate force measurements in the nanotechnology and biophysics areas, we present an atomic force microscope (AFM) cantilever calibration system, the 'nano force calibrator' (NFC), consisting of a microbalance and a precision translation stage. Calibration using the NFC has proved to be a reliable and accurate method through a series of experiments with a commercial piezoresistive AFM cantilever. In these experiments, linearity, repeatability and reproducibility of measurements were investigated along with the effects of calibration conditions, such as orientation of the cantilever and temperature. Uncertainty analysis shows that the stiffness and force sensitivity are determined to be 3.385 N m-1 and 0.6490 µN Ω-1, which are traceable to the Système International d'Unités (SI units). The relative standard uncertainties of both the stiffness and sensitivity are approximately 0.4% or conservatively 0.5%.

  6. International Cooperation in Big Science: High Energy Physics. Science Policy Study--Hearings Volume 4. Hearing before the Task Force on Science Policy of the Committee on Science and Technology, House of Representatives, Ninety-Ninth Congress, First Session (April 25, 1985).

    ERIC Educational Resources Information Center

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

    Presented is the first in a series of four hearings on international cooperation in science. The focus of the hearing is international cooperation in big science, as personified by the field of high energy physics. The particular area of interest is the questions: What are the past experience and future prospects for international costsharing of…

  7. On the use of different coordinate systems in mechanochemical force analyses

    NASA Astrophysics Data System (ADS)

    Stauch, Tim; Dreuw, Andreas

    2015-08-01

    Force analyses are crucial for a comprehensive understanding of mechanochemical processes. The choice of coordinate system in these kinds of analyses is a nontrivial task that determines the quality and validity of the obtained results. Here, we study the suitability of different sets of coordinates for mechanical force analyses, i.e., normal modes, delocalized internal, redundant internal, and Z-matrix coordinates. After discussing the theoretical foundations of force analyses using different coordinate systems, we investigate a number of test molecules. We show that normal modes and Z-matrix coordinates deliver useful results only if certain requirements are fulfilled and that only redundant internal coordinates yield meaningful results in all cases.

  8. 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…

  9. Contractile forces driving embryonic development

    NASA Astrophysics Data System (ADS)

    Kaschube, Matthias

    2011-03-01

    Proper development of an organism requires an orchestrated interplay of large sets of components. Recent developments in live fluorescent imaging methods allow the visualization of many key proteins in cells and tissues. Developing quantitative image analysis methods to measure the dynamics of shape changes in individual cells is central for understanding how a tissue gets sculpted, what molecular machineries are driving this process, and what interactions between cells are regulating it. In this talk, I will present recent advances in our understanding of the dynamical processes during morphogenesis, focusing on the example of tissue folding and invagination at the beginning of gastrulation in Drosophila. I show that this process is driven by a contractile multicellular actomyosin meshwork that dynamically forms within a few minutes at the cell surfaces. In individual cells, contraction is pulsed, with phases of contraction interrupted by pauses in which the cell size is maintained, i.e. a ratchet type dynamics that reduces the surface area of cells incrementally. Measuring the dynamics of whole cell shape changes in 2-photon live imaging data reveals that contraction pulses drive cell lengthening and relocation of cell nuclei, two transformations that are essential for successful invagination of tissue. This analysis further shows that over subsequent stages of invagination, during which cells undergo an elaborate sequence of shape changes, the volume of individual cells is a preserved quantity. These results shed new light on the forces and cellular dynamics driving tissue morphogenesis and are a step towards a quantitative understanding of how an organism's shape and internal structure arises in development.

  10. 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.

  11. 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.

  12. 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

  13. Hydrodynamic force microscopy

    NASA Astrophysics Data System (ADS)

    Ulrich, Elaine Schmid

    Microfluidic networks and microporous materials have long been of interest in areas such as hydrology, petroleum engineering, chemical and electrochemical engineering, medicine and biochemical engineering. With the emergence of new processes in gas separation, cell sorting, ultrafiltration, and advanced materials synthesis, the importance of building a better qualitative and quantitative understanding of these key technologies has become apparent. However, microfluidic measurement and theory is still relatively underdeveloped, presenting a significant obstacle to the systematic design of microfluidic devices and materials. Theoretical challenges arise from the breakdown of classical viscous flow models as the flow dimensions approach the mean free path of individual molecules. Experimental challenges arise from the lack of flow profilometry techniques at sub-micron length scales. Here we present an extension of scanning probe microscopy techniques, which we have termed Hydrodynamic Force Microscopy (HFM). HFM exploits fluid drag to profile microflows and to map the permeability of microporous materials. In this technique, an atomic force microscope (AFM) cantilever is scanned close to a microporous sample surface. The hydrodynamic interactions arising from a pressure-driven flow through the sample are then detected by mapping the deflection of an AFM cantilever. For gas flows at atmospheric pressure, HFM has been shown to achieve a velocity sensitivity of 1 cm/s with a spatial resolution of ˜ 10 nm. This compares very favorably to established techniques such as hot-wire and laser Doppler anemometry, whose spatial resolutions typically exceed 1 mum and which may rely on the use of tracer particles or flow markers1. We demonstrate that HFM can successfully profile Poiseuille flows inside pores as small as 100 nm and can distinguish Poiseuille flow from uniform flow for short entry lengths. HFM detection of fluid jets escaping from porous samples can also reveal a "permeability map" of a sample's pore structure, allowing us to distinguish between clear and blocked pores, even in cases where the subsurface fouling is undetectable by conventional AFM. The experimental data is discussed in context with theoretical aspects of HFM microflow measurement and practical limits of this technique. Finally, we conclude with variations of standard HFM techniques that show some promise for investigation of smaller nanometer-scale flows of gases and liquids.

  14. 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)

  15. California's Teaching Force: Key Issues and Trends, 2008

    ERIC Educational Resources Information Center

    Plattner, Andy

    2008-01-01

    For each of the past 10 years, the Center for the Future of Teaching and Learning has issued a report on the status of California's teaching force based on research conducted by SRI International. The Center provides practical information to help policymakers and education leaders understand the challenges they face is provided. Context, clarity…

  16. 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.

  17. Deep atomic force microscopy

    PubMed Central

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

    2013-01-01

    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. PMID:24387435

  18. 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.

  19. 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.

  20. 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 34billionbarrels of oil (~4.7trillionmetrictons) and 9billiontons 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 355trilliontons, 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

  1. In-plane video force microscopy of morphogenesis in epithelia

    NASA Astrophysics Data System (ADS)

    Hutson, M. Shane; Mashburn, David; Copenhaver, Eric; McCleery, W. Tyler; Veldhuis, Jim; Kim, Steven; Brodland, G. Wayne

    2013-03-01

    Video force microscopy (VFM) is a technique that takes segmented time-lapse images as input and makes least-squares estimates for the cell-edge tensions and cell-internal pressures needed to drive observed changes in cell shape. VFM has previously been used to estimate the cell-level forces that drive invagination during Drosophila gastrulation. Doing so required time-lapse images containing entire cross-sections of the embryo. Here, we extend video force microscopy to in-plane images of epithelia - including examples in which the images cover only a small region of a larger epithelium. This extension requires imposition of constraints on the average cell-internal pressure and the average stress external to the observed patch. We will demonstrate successful estimation of forces in exact models, as well as anomalous cases that prevent successful force estimation. We will then show applications of this technique for inferring the forces driving Drosophila germband retraction and wound healing. Supported by NIH 1R01GM099107

  2. Forced circumcision of men (abridged).

    PubMed

    Glass, Michael

    2014-08-01

    The forced circumcision of men is a widespread human rights abuse that often accompanies other human rights violations. It occurs in clashes between circumcising and non-circumcising cultures, or when individuals in circumcising cultures reject circumcision. This article documents the forced circumcision of men against their will, shows how evidence of forced circumcision has been downplayed and discounted, and outlines and discusses some measures that could help to reduce its prevalence. PMID:24014634

  3. Surgical Force-Measuring Probe

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Roberts, Paul W.; Scott, Charles E.

    1993-01-01

    Aerodynamic balance adapted to medical use. Electromechanical probe measures forces and moments applied to human tissue during surgery. Measurements used to document optimum forces and moments for surgical research and training. In neurosurgical research, measurements correlated with monitored responses of nerves. In training, students learn procedures by emulating forces used by experienced surgeons. Lightweight, pen-shaped probe easily held by surgeon. Cable feeds output signals to processing circuitry.

  4. Collision forces for compliant projectiles

    NASA Technical Reports Server (NTRS)

    Grady, Joseph E.

    1990-01-01

    Force histories resulting from the impact of compliant projectiles were determined experimentally. A long instrumented rod was used as the target, and the impact force was calculated directly from the measured strain response. Results from a series of tests on several different sized impactors were used to define four dimensionless parameters that determine, for a specified impactor velocity and size, the amplitude, duration, shape, and impulse of the impact force history.

  5. Trends of measured climate forcing agents

    NASA Astrophysics Data System (ADS)

    Hansen, James E.; Sato, Makiko

    2001-12-01

    * National Aeronautics and Space Administration, Goddard Institute for Space Studies, New York, NY 10025; and Center for Climate Systems Research, Columbia University Earth Institute, New York, NY 10025 Contributed by James E. Hansen, October 16, 2001 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.

  6. Climate forcing by stratospheric aerosols

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew; Hansen, James; Sato, Makiko

    1992-01-01

    It is illustrated how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosols size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, r(eff). If r(eff) is greater than about 2 microns, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a surface heating. The aerosol climate forcing is less sensitive to other characteristics of the size distribution, the aerosol composition, and the altitude of the aerosols. Thus stratospheric aerosol forcing can be defined accurately from measurements of aerosol extinction over a broad wavelength range.

  7. 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.

  8. 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.

  9. 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.

  10. Climate forcing by stratospheric aerosols

    NASA Astrophysics Data System (ADS)

    Lacis, Andrew; Hansen, James; Sato, Makiko

    1992-08-01

    We illustrate how climate forcing by stratospheric aerosols depends on aerosol properties. The climate forcing is a function of aerosol size distribution, but the size dependence can be described well by a single parameter: the area-weighted mean radius, reff.If reff is greater than about 2 ?m, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a surface heating. The aerosol climate forcing is less sensitive to other characteristics of the size distribution, the aerosol composition, and the altitude of the aerosols. Thus stratospheric aerosol forcing can be defined accurately from measurements of aerosol, extinction over a broad wavelength range.

  11. Magnetic microposts as an approach to apply forces to living cells

    PubMed Central

    Sniadecki, Nathan J.; Anguelouch, Alexandre; Yang, Michael T.; Lamb, Corinne M.; Liu, Zhijun; Kirschner, Stuart B.; Liu, Yaohua; Reich, Daniel H.; Chen, Christopher S.

    2007-01-01

    Cells respond to mechanical forces whether applied externally or generated internally via the cytoskeleton. To study the cellular response to forces separately, we applied external forces to cells via microfabricated magnetic posts containing cobalt nanowires interspersed among an array of elastomeric posts, which acted as independent sensors to cellular traction forces. A magnetic field induced torque in the nanowires, which deflected the magnetic posts and imparted force to individual adhesions of cells attached to the array. Using this system, we examined the cellular reaction to applied forces and found that applying a step force led to an increase in local focal adhesion size at the site of application but not at nearby nonmagnetic posts. Focal adhesion recruitment was enhanced further when cells were subjected to multiple force actuations within the same time interval. Recording the traction forces in response to such force stimulation revealed two responses: a sudden loss in contractility that occurred within the first minute of stimulation or a gradual decay in contractility over several minutes. For both types of responses, the subcellular distribution of loss in traction forces was not confined to locations near the actuated micropost, nor uniformly across the whole cell, but instead occurred at discrete locations along the cell periphery. Together, these data reveal an important dynamic biological relationship between external and internal forces and demonstrate the utility of this microfabricated system to explore this interaction. PMID:17804810

  12. 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…

  13. 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.

  14. 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 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. Electronic supplementary information (ESI) available: Video S1. Detachment of a S. pyogenes cell chain from glass substrate. The cantilever is approached on the outermost adherent cell of a chain and four bacteria were then sequentially detached. The sequential cell detachment suddenly stopped after four bacteria. This possibly occurred because bacteria-glass interactions became too strong or the maximal probe retraction was reached. The cells spontaneously detached from the cantilever flipping back on the surface. Fig. S1. (A) Adhesion force-distance and (B) adhesion force-detaching work correlation of E.coli on PLL for setpoints of 1 and 10 nN. Circle: 1 nN setpoint, square: 10 nN. See DOI: 10.1039/c4nr06495j

  15. Radiative forcing and climate response

    NASA Astrophysics Data System (ADS)

    Hansen, J.; Sato, M.; Ruedy, R.

    1997-03-01

    We examine the sensitivity of a climate model to a wide range of radiative forcings, including changes of solar irradiance, atmospheric CO2, O3, CFCs, clouds, aerosols, surface albedo, and a "ghost" forcing introduced at arbitrary heights, latitudes, longitudes, seasons, and times of day. We show that, in general, the climate response, specifically the global mean temperature change, is sensitive to the altitude, latitude, and nature of the forcing; that is, the response to a given forcing can vary by 50% or more depending upon characteristics of the forcing other than its magnitude measured in watts per square meter. The consistency of the response among different forcings is higher, within 20% or better, for most of the globally distributed forcings suspected of influencing global mean temperature in the past century, but exceptions occur for certain changes of ozone or absorbing aerosols, for which the climate response is less well behaved. In all cases the physical basis for the variations of the response can be understood. The principal mechanisms involve alterations of lapse rate and decrease (increase) of large-scale cloud cover in layers that are preferentially heated (cooled). Although the magnitude of these effects must be model-dependent, the existence and sense of the mechanisms appear to be reasonable. Overall, we reaffirm the value of the radiative forcing concept for predicting climate response and for comparative studies of different forcings; indeed, the present results can help improve the accuracy of such analyses and define error estimates. Our results also emphasize the need for measurements having the specificity and precision needed to define poorly known forcings such as absorbing aerosols and ozone change. Available data on aerosol single scatter albedo imply that anthropogenic aerosols cause less cooling than has commonly been assumed. However, negative forcing due to the net ozone change since 1979 appears to have counterbalanced 30-50% of the positive forcing due to the increase of well-mixed greenhouse gases in the same period. As the net ozone change includes halogen-driven ozone depletion with negative radiative forcing and a tropospheric ozone increase with positive radiative forcing, it is possible that the halogen-driven ozone depletion has counterbalanced more than half of the radiative forcing due to well-mixed greenhouse gases since 1979.

  16. International Education for Wisconsin.

    ERIC Educational Resources Information Center

    Moebius, Barbara

    1990-01-01

    Describes an international trade education program offered by Waukesha (WI) County Technical College. The program includes international business principles, international marketing, cultural awareness, business Spanish, international documentation, transportation, and finance. (JOW)

  17. 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.

  18. Position/force control in multiple-manipulator systems

    NASA Technical Reports Server (NTRS)

    Wen, John T.; Murphy, Steve H.

    1992-01-01

    Multiple-manipulator systems show great potential for accomplishing many tasks beyond the capabilities of a single manipulator. A fundamental task is the control of both the motion and the force of a common payload. Despite the recent progress in the motion and force control of multiple manipulators, there has been a continuing question on which physical force should be and can be controlled. The frequently used orthogonal decomposition is plagued by a unit inconsistency problem, rendering its physical interpretation difficult, if not impossible. This paper discusses one concept of internal force and shows how its regulation can be handled by the existing approaches. The many approaches to the position control of multiple manipulators are categorized, and a detailed outline of a straightforward form of multiple manipulator control is presented.

  19. 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…

  20. Force approach to radiation reaction

    NASA Astrophysics Data System (ADS)

    López, Gustavo V.

    2016-02-01

    The difficulty of the usual approach to deal with the radiation reaction is pointed out, and under the condition that the radiation force must be a function of the external force and is zero whenever the external force be zero, a new and straightforward approach to radiation reaction force and damping is proposed. Starting from the Larmor formula for the power radiated by an accelerated charged particle, written in terms of the applied force instead of the acceleration, an expression for the radiation force is established in general, and applied to the examples for the linear and circular motion of a charged particle. This expression is quadratic in the magnitude of the applied force, inversely proportional to the speed of the charged particle, and directed opposite to the velocity vector. This force approach may contribute to the solution of the very old problem of incorporating the radiation reaction to the motion of the charged particles, and future experiments may tell us whether or not this approach point is in the right direction.

  1. 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

  2. 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…

  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. 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

  5. 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.

  6. Radiative forcing from forest disturbances

    NASA Astrophysics Data System (ADS)

    O'Halloran, T. L.; Law, B. E.; Wang, Z.; Barr, J.; Schaaf, C.; Brown, M.; Goulden, M.; Goeckede, M.; Fuentes, J. D.; Black, T. A.; Engel, V.

    2010-12-01

    Natural disturbances are major regulators of the global carbon cycle. In the case of boreal fire, it is known that the resulting increase to surface albedo can offset the warming from the concomitant release of greenhouse gasses. Based on an analysis of AmeriFlux and MODIS data, we show that two other major disturbance types also significantly alter surface albedo, and the resulting radiative forcing is on the same order of magnitude as the CO2 forcing. The direction of the albedo forcing can be either positive (heating) or negative (cooling), depending on surface properties. However, for two major disturbance types that are increasing in extent under climate change, the negative forcing from albedo outweighs the positive carbon forcing, reducing the likelihood of reinforcing climate feedbacks.

  7. Air Force satellite position management

    NASA Technical Reports Server (NTRS)

    Davis, R.

    1985-01-01

    The Space Act of 1958 identified the Department of Defense as responsible for conducting military operations in space. Subsequently, the United States Air Force was assigned to act as the DOD's executive agent for space. In addition, the Air Force is responsible for acquisition and launch of DOD space systems. Within the Air Force, space related roles and activities have been delegated to several subordinate organizations and agencies. The roles and responsibilities of agencies are still evolving. The Air Force has designated the Air Force System Command's Space Division as its office of primary responsibility for satellite position management. Spacecraft program offices at Space Division are required by regulation to include position management planning in both prelaunch and orbital phases of spacecraft development and operation.

  8. 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.

  9. 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

  10. 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.

  11. 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...

  12. Inverse problem of scanning force microscope force measurements

    NASA Astrophysics Data System (ADS)

    Todd, Brian A.; Eppell, Steven J.

    2003-09-01

    The Hooke's Law model, traditionally used to determine forces from the deflection of scanning force microscope (SFM) cantilevers, restricts the bandwidth to well below the cantilever resonant frequency. The limitation imposed on measurements by Hooke's Law can be overcome by modeling the multimodal and dynamical response of the cantilever (i.e., accounting for the viscous and inertial response) using a beam model. However, when calculating the forces on the cantilever from deflection measurements, this "inverse problem" is ill posed (i.e., it amplifies noise in the measurement, so that simple inversion produces useless solutions). Regularization techniques provide mathematical solutions to this ill-posed problem but introduce nontrivial mechanisms by which inputs to the system are propagated to outputs. In this article, we investigate the propagation of errors in the inverse problem of SFM force measurements. We first develop a noise model and validate it using experimental measurements. This is then applied to simulate a force-distance experiment with a relevant amount of noise. This provides a cantilever deflection signal based on known forces with which to evaluate the accuracy and precision of a force reconstruction algorithm. We show that Tikhonov regularized solutions obtained with an L-curve analysis reconstruct forces with an accuracy of better than 90% on average but with poor precision, yielding a signal-to-noise ratio of ˜2 for a 0.02 N/m cantilever. Ensemble averaging is recommended to improve the precision. This allows both accurate and precise force curves to be reconstructed with a high bandwidth.

  13. Does an instrumented treadmill correctly measure the ground reaction forces?

    PubMed Central

    Willems, Patrick A.; Gosseye, Thierry P.

    2013-01-01

    Summary Since the 1990s, treadmills have been equipped with multi-axis force transducers to measure the three components of the ground reaction forces during walking and running. These measurements are correctly performed if the whole treadmill (including the motor) is mounted on the transducers. In this case, the acceleration of the treadmill centre of mass relative to the reference frame of the laboratory is nil. The external forces exerted on one side of the treadmill are thus equal in magnitude and opposite in direction to the external forces exerted on the other side. However, uncertainty exists about the accuracy of these measures: due to friction between the belt and the tread-surface, due to the motor pulling the belt, some believe that it is not possible to correctly measure the horizontal components of the forces exerted by the feet on the belt. Here, we propose a simple model of an instrumented treadmill and we demonstrate (1) that the forces exerted by the subject moving on the upper part of the treadmill are accurately transmitted to the transducers placed under it and (2) that all internal forces – including friction – between the parts of the treadmill are cancelling each other. PMID:24285705

  14. 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.

  15. Experimental characterization of jet static forces impacting waste tank components

    SciTech Connect

    Bamberger, J.A.; Bates, J.M. ); Waters, E.D. )

    1990-06-01

    Westinghouse Hanford Company plans to install mixer pumps in doubleshell waste tanks to mobilize and suspend settled sludge to allow eventual retrieval for treatment and permanent storage. The mixer pumps produce high momentum, horizontally directed jets that impact and mobilize the sludge and mix it into slurry for removal. There is concern that the force of the jet may damage tank internal components in its path. Scaled experiments were conducted to characterize the velocity profiles of the floor jet and to quantify the drag coefficients and impact forces for three tank components: radiation dry well, air lift circulator, and steam coil. Jet impact forces were measured on the scaled models at a 4 to 1 range of hydraulically scaled flow rates and a scaled range of distances between discharge nozzle and test component. The test were designed to provide hydraulic similarity between test conditions and expected actual waste tank conditions by using equal Reynolds number the jet maximum velocity impacted the test component. Forces measured on the models were used to calculate expected forces on the full scale components. Correlations of force on the test article versus distance from the nozzle were derived for the radiation dry well and air lift circulator based on the velocity correlation and drag parameter. The force data were also used to derive equivalent drag parameters which accounted for component shape factors including variation of jet impact area on the test article with distance from the nozzle. 8 refs., 44 figs., 42 tabs.

  16. 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.

  17. International Relations, Social Studies: 6448.20.

    ERIC Educational Resources Information Center

    Coe, Rose Marie

    The forces affecting relations among nations as well as the effectiveness of decision making processes in international politics are examined and analyzed by 10th through 12th grade students in the elective quinmester course clustering around political studies. Goals emphasize helping students to understand state interaction and the variables…

  18. 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.

  19. A HUD Handbook. Urban Intern Training.

    ERIC Educational Resources Information Center

    Department of Housing and Urban Development, Washington, DC.

    The Urban Internship Program has been established to recruit and train above average graduate and undergraduate students to fill program leadership positions in the Department of Housing and Urban Development (HUD). The program provides orientation to major HUD programs to integrate the intern into the work force quickly and effectively and…

  20. 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,…

  1. 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.…

  2. Screening for Ovarian Cancer: U.S. Preventive Services Task Force Reaffirmation Recommendation

    MedlinePlus

    ... of Internal Medicine Summaries for Patients Screening for Ovarian Cancer: U.S. Preventive Services Task Force Reaffirmation Recommendation Statement The full report is titled “Screening for Ovarian Cancer: U.S. Preventive Services Task Force Reaffirmation Recommendation Statement.” ...

  3. 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...

  4. Doctors Should Screen Teens for Major Depression, U.S. Task Force Says

    MedlinePlus

    ... online Feb. 9 in the Annals of Internal Medicine and Pediatrics . The task force is an independent, volunteer panel of national experts who regularly review the scientific evidence and make recommendations regarding health ... U.S. Preventive Services Task Force, news release, ...

  5. 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... 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...

  6. 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... 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...

  7. 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...

  8. 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... 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...

  9. 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... 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...

  10. 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

  11. Climate Forcing by Anthropogenic Aerosols

    NASA Astrophysics Data System (ADS)

    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.

  12. Electrostatic Force in Blowing Snow

    NASA Astrophysics Data System (ADS)

    Schmidt, D. S.; Schmidt, R. A.; Dent, J. D.

    Separation of electrostatic charge during the transport of particles by wind adds a force to the gravitational and fluid forces that determine trajectories of particles moving by saltation. Evaluating this electrostatic force requires the electric field strength very near the saltation surface, and charge-to-mass ratios for the moving particles. Field mill readings 4 cm above the surface in a moderate blizzard showed electric field strength as high as +30 kV m-1. Another experiment gave charge-to-mass ratios of individual saltation particles in low-level drifting that ranged between +72 C kg-1 and -208 C kg-1. From these measurements, we estimated electrostatic forces as large as the gravitational force on some saltating particles. Including forces of this magnitude in the equations of motion significantly alters predicted saltation trajectories from those for uncharged particles. Predictions appear reasonable that for some saltating particles, the electrostatic force prevents new surface impacts. These results should help improve models of energy transfer in the planetary boundary layer during blizzards and sandstorms.

  13. 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

  14. 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.

  15. 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…

  16. 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.

  17. 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 black and organic matter using year 2000 emissions are +0.46 W m-2 and -0.17 W m-2, respectively; anthropogenic forcing is +0.38 W m-2 and -0.12 W m-2. The black carbon value is only 11% higher than that of the Intergovernmental Panel on Climate Change (IPCC), although this value includes enhanced absorption due to internal mixing.

  18. 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.

  19. 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.

  20. 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.}

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Boundary Conditions and Casimir Forces

    NASA Astrophysics Data System (ADS)

    Graham, Noah; Quandt, Markus; Weigel, Herbert

    As an important application of the spectral method we study the Casimir effect. The Casimir effect and the corresponding force were originally discovered in 1947 by Casimir and Polder in their study of the relativistic van der Waals force between neutral atoms [1]. In the same year, Casimir showed that the tiny force between grounded conducting plates could be understood as a modification of the vacuum fluctuations of the electromagnetic field due to conducting boundary conditions on the plates [2]. There has been renewed interest in the Casimir force from applied physics because of its importance at nanometer scales and, in particular, in micro-mechanical devices. For a comprehensive overview, see Ref. [3].

  7. 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.

  8. Labor Force Trends: A Bibliography

    ERIC Educational Resources Information Center

    Devens, Richard M.

    1977-01-01

    This annotated bibliography reflects relevant issues covered in the accompanying article in this issue (CE 506 866). It presents a general outline of recent literature on labor force participation, including underlying secular movements and cyclical analysis. (MF)

  9. A Graphene Surface Force Balance

    PubMed Central

    2014-01-01

    We report a method for transferring graphene, grown by chemical vapor deposition, which produces ultraflat graphene surfaces (root-mean-square roughness of 0.19 nm) free from polymer residues over macroscopic areas (>1 cm2). The critical step in preparing such surfaces involves the use of an intermediate mica template, which itself is atomically smooth. We demonstrate the compatibility of these model surfaces with the surface force balance, opening up the possibility of measuring normal and lateral forces, including friction and adhesion, between two graphene sheets either in contact or across a liquid medium. The conductivity of the graphene surfaces allows forces to be measured while controlling the surface potential. This new apparatus, the graphene surface force balance, is expected to be of importance to the future understanding of graphene in applications from lubrication to electrochemical energy storage systems. PMID:25171130

  10. Molecular Force Spectroscopy on Cells

    NASA Astrophysics Data System (ADS)

    Liu, Baoyu; Chen, Wei; Zhu, Cheng

    2015-04-01

    Molecular force spectroscopy has become a powerful tool to study how mechanics regulates biology, especially the mechanical regulation of molecular interactions and its impact on cellular functions. This force-driven methodology has uncovered a wealth of new information of the physical chemistry of molecular bonds for various biological systems. The new concepts, qualitative and quantitative measures describing bond behavior under force, and structural bases underlying these phenomena have substantially advanced our fundamental understanding of the inner workings of biological systems from the nanoscale (molecule) to the microscale (cell), elucidated basic molecular mechanisms of a wide range of important biological processes, and provided opportunities for engineering applications. Here, we review major force spectroscopic assays, conceptual developments of mechanically regulated kinetics of molecular interactions, and their biological relevance. We also present current challenges and highlight future directions.

  11. 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)

  12. Calibration of lateral force measurements in atomic force microscopy with a piezoresistive force sensor.

    PubMed

    Xie, Hui; Vitard, Julien; Haliyo, Sinan; Régnier, Stéphane; Boukallel, Mehdi

    2008-03-01

    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. PMID:18377016

  13. 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.

  14. The force balance of sea ice in a numerical model of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Steele, Michael; Zhang, Jinlun; Rothrock, Drew; Stern, Harry

    1997-09-01

    The balance of forces in the sea ice model of Hibler [1979] is examined. The model predicts that internal stress gradients are an important force in much of the Arctic Ocean except in summer, when they are significant only off the northern coasts of Greenland and the Canadian Archipelago. A partition of the internal stress gradient between the pressure gradient and the viscous terms reveals that both are significant, although they operate on very different timescales. The acceleration term is generally negligible, while the sum of Coriolis plus sea surface tilt is small. Thus the seasonal average force balance in fall, winter, and spring is mostly between three terms of roughly equal magnitudes: air drag, water drag, and internal stress gradients. This is also true for the monthly average force balance. However, we find that there is a transition around the weekly timescale and that on a daily basis the force balance at a particular location and time is often between only two terms: either between air drag and water drag or between air drag and internal stress gradients. The model is in agreement with the observations of Thorndike and Colony [1982] in that the correlation between geostrophic wind forcing and the model's ice velocity field is high. This result is discussed in the context of the force balance; we show that the presence of significant internal stress gradients does not preclude high wind-ice correlation. A breakdown of the internal stress gradient into component parts reveals that the shear viscous force is far from negligible, which casts strong doubt on the theoretical validity of the cavitating fluid approximation (in which this component is neglected). Finally, the role of ice pressure is examined by varying the parameter P*. We find a strong sensitivity in terms of the force balance, as well as ice thickness and velocity.

  15. 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.

  16. A new force in nature?

    NASA Astrophysics Data System (ADS)

    Fischbach, Ephraim; Sudarsky, Daniel; Szafer, Aaron; Talmadge, Carrick; Aronson, S. H.

    1986-10-01

    We review recent experimental and theoretical work dealing with the proposed fifth force. Further analysis of the original Eötvös experiments has uncovered no challenges to our original assertion that these data evidence a correlation characteristic of the presence of a new coupling to baryon number or hypercharge. Various models suggest that the proposed fifth force could be accomodated naturally into the existing theoretical framework.

  17. 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.

  18. 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 Schwarzschild background.

  19. 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.

  20. 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.

  1. Magnetic Force Microscopy in Liquids.

    PubMed

    Ares, Pablo; Jaafar, Miriam; Gil, Adriana; Gmez-Herrero, Julio; Asenjo, Agustina

    2015-09-01

    In this work, the use of magnetic force microscopy (MFM) to acquire images of magnetic nanostructures in liquid environments is presented. Optimization of the MFM signal acquisition in liquid media is performed and it is applied to characterize the magnetic signal of magnetite nanoparticles. The ability for detecting magnetic nanostructures along with the well-known capabilities of atomic force microscopy in liquids suggests potential applications in fields such as nanomedicine, nanobiotechnology, or nanocatalysis. PMID:26150330

  2. 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

  3. 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…

  4. 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

  5. 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

  6. 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.

  7. Force transmission in migrating cells.

    PubMed

    Fournier, Maxime F; Sauser, Roger; Ambrosi, Davide; Meister, Jean-Jacques; Verkhovsky, Alexander B

    2010-01-25

    During cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity and traction forces at the substrate in a model system of persistently migrating fish epidermal keratocytes. Front and lateral sides of the cell exhibited much stronger coupling between actin motion and traction forces than the trailing cell body. Further analysis of the traction-velocity relationship suggested that the force transmission mechanisms were different in different cell regions: at the front, traction was generated by a gripping of the actin network to the substrate, whereas at the sides and back, it was produced by the network's slipping over the substrate. Treatment with inhibitors of the actin-myosin system demonstrated that the cell body translocation could be powered by either of the two different processes, actomyosin contraction or actin assembly, with the former associated with significantly larger traction forces than the latter. PMID:20100912

  8. International Human Rights and International Education.

    ERIC Educational Resources Information Center

    Buergenthal, Thomas; Torney, Judith V.

    The purpose of this book is to raise the level of awareness and understanding of educators concerning the issues, problems, and efforts in international human rights. Intended for teachers, administrators, and curriculum writers, the book discusses human rights activities of international and regional organizations, principles of international

  9. 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…

  10. Improving the Delivery of the Undergraduate International Business Course.

    ERIC Educational Resources Information Center

    Thanopoulos, John; And Others

    1995-01-01

    The components of an undergraduate international business (IB) course, developed and taught according to corporate suggestions, are correlated with the importance ascribed to them by students taking the class. Students felt all 21 components should be emphasized, especially the sociocultural/political/legal forces in IB, international finance, and…

  11. 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.

  12. Developing Curriculum: Knowledge and Skills Essential for an International Salesforce.

    ERIC Educational Resources Information Center

    Ruhland, Sheila K.

    A study explored the additional knowledge and skills an international salesforce needs based upon 95 respondents from Wisconsin manufacturing companies. Six areas were evaluated by sales representatives involved with international sales and marketing to identify the education and training needed within the next 3 years by the work force. Four…

  13. 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.

  14. 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

  15. 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...

  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, 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...

  18. Bite force measurement in mandibular parasymphyseal fractures: a preliminary clinical study.

    PubMed

    Kshirsagar, Rajesh; Jaggi, Nitin; Halli, Rajshekhar

    2011-12-01

    We measured the amount of bite force generated by patients treated for parasymphyseal fractures of the mandible by open reduction and internal fixation at various predetermined time intervals. Sixty volunteers ranging from 18 to 60 years old were selected as the control group. All measurements were made on a bite force measurement device with the head in an upright position and in an unsupported natural position. Bite forces were measured at the incisor and right and left molar regions. These bite forces were compared with six patients with isolated mandibular unilateral parasymphyseal fractures. All patients were operated using open reduction and internal fixation using two miniplates at the fracture site. In the volunteer group, bite forces ranged from 22 to 50 kg in the molar region and 3 to 27 kg in the incisor region. Mean adult healthy values (male and female) in the molar region were 36 kg and in the incisor region, 15 kg. In mandibular parasymphyseal fractures, incisor bite forces were reduced significantly when compared with the control group in the first 2 postoperative weeks and regained significantly thereafter till 4 to 6 weeks. Bite forces in the molar region took ~6 to 12 weeks to regain maximum bite forces when compared with the volunteer group. Restoration of functional bite forces was evident by 6 to 8 weeks. However, the restoration of maximum bite forces may require up to 12 weeks in parasymphyseal fractures. PMID:23205177

  19. Bite Force Measurement in Mandibular Parasymphyseal Fractures: A Preliminary Clinical Study

    PubMed Central

    Kshirsagar, Rajesh; Jaggi, Nitin; Halli, Rajshekhar

    2011-01-01

    We measured the amount of bite force generated by patients treated for parasymphyseal fractures of the mandible by open reduction and internal fixation at various predetermined time intervals. Sixty volunteers ranging from 18 to 60 years old were selected as the control group. All measurements were made on a bite force measurement device with the head in an upright position and in an unsupported natural position. Bite forces were measured at the incisor and right and left molar regions. These bite forces were compared with six patients with isolated mandibular unilateral parasymphyseal fractures. All patients were operated using open reduction and internal fixation using two miniplates at the fracture site. In the volunteer group, bite forces ranged from 22 to 50 kg in the molar region and 3 to 27 kg in the incisor region. Mean adult healthy values (male and female) in the molar region were 36 kg and in the incisor region, 15 kg. In mandibular parasymphyseal fractures, incisor bite forces were reduced significantly when compared with the control group in the first 2 postoperative weeks and regained significantly thereafter till 4 to 6 weeks. Bite forces in the molar region took ~6 to 12 weeks to regain maximum bite forces when compared with the volunteer group. Restoration of functional bite forces was evident by 6 to 8 weeks. However, the restoration of maximum bite forces may require up to 12 weeks in parasymphyseal fractures. PMID:23205177

  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. 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

  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. 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.

  4. 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.

  5. 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…

  6. 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…

  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. Forced and coerced sterilization of women in Europe.

    PubMed

    Zampas, Christina; Lama?kov, Adriana

    2011-08-01

    Human rights provisions in laws set by international treaties and national legislatures make individuals' informed and freely given consent a precondition to the legality of their sterilization. Nevertheless, evidence shows that sterilizations have been undertaken by forceful means or coerced acceptance, to which women do not genuinely consent. The women are often members of ethnic minorities in their countries, such as Roma women, or adolescent or disabled women. Some European governments have acknowledged their responsibility for human rights abuses by forced and coerced sterilization of vulnerable women, and committees established by international human rights treaties to monitor states' compliance with their standards are increasingly vigilant to expose and condemn wrongful sterilization. For instance, the committee monitoring compliance with the Convention on the Elimination of All Forms of Discrimination against Women and the Council of Europe's Commissioner for Human Rights provide guidance for the prevention of violations. PMID:21683952

  10. 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.

  11. 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.

  12. Capillary Force between Flexible Filaments.

    PubMed

    Soleimani, Majid; Hill, Reghan J; van de Ven, Theo G M

    2015-08-01

    Liquid droplets bridging filaments are ubiquitous in nature and technology. Although the liquid-surface shape and the capillary force and torque have been studied extensively, the effect of filament flexibility is poorly understood. Here, we show that elastic deformation (at large values of the elasto-capillary number) can significantly affect the liquid-surface shape and capillary force. The equilibrium state of parallel filaments is calculated using analytical approximations and numerical solutions for the fluid interface. The results compare well, and the numerical solution is then applied to crossing filaments. In the investigated range of parameters, the capillary force increases rapidly when the filaments touch. The force decreases continuously when decreasing the liquid volume for parallel hydrophilic filaments but produces a maximum for crossed filaments. The liquid volume at the maximum force is reported when changing the filament flexibility, crossing angle, and contact angle. These results may be beneficial in applications where the strength and structure of wet fibrous materials are important, such as in paper formation and when welding flexible components. PMID:26158380

  13. Thermal-induced force release in oxyhemoglobin

    PubMed Central

    Gevorkian, S. G.; Allahverdyan, A. E.; Gevorgyan, D. S.; Hu, Chin-Kun

    2015-01-01

    Oxygen is released to living tissues via conformational changes of hemoglobin from R-state (oxyhemoglobin) to T-state (desoxyhemoglobin). The detailed mechanism of this process is not yet fully understood. We have carried out micromechanical experiments on oxyhemoglobin crystals to determine the behavior of the Young’s modulus and the internal friction for temperatures between 20 °C and 70 °C. We have found that around 49 °C oxyhemoglobin crystal samples undergo a sudden and strong increase of their Young’s modulus, accompanied by a sudden decrease of the internal friction. This sudden mechanical change (and the ensuing force release) takes place in a partially unfolded state and precedes the full denaturation transition at higher temperatures. After this transformation, the hemoglobin crystals have the same mechanical properties as their initial state at room temperatures. We conjecture that it can be relevant for explaining the oxygen-releasing function of native oxyhemoglobin when the temperature is increased, e.g. due to active sport. The effect is specific for the quaternary structure of hemoglobin, and is absent for myoglobin with only one peptide sequence. PMID:26277901

  14. Fluorescence-force spectroscopy at the single molecule level

    NASA Astrophysics Data System (ADS)

    Zhou, Ruobo

    During the past decade, various powerful single-molecule techniques have evolved and helped to address important questions in life sciences. As the single molecule techniques become mature, there is increasingly pressing need to maximize the information content of the analysis in order to be able to study more complex systems that better approximate in-vivo conditions. Here, we develop a fluorescence-force spectroscopy method to combine single-molecule fluorescence spectroscopy with optical tweezers. Optical tweezers are used to manipulate and observe mechanical properties on the nanometer scale and piconewton force range. However, once the force range is in the low piconewton range or less, the spatial resolution of optical tweezers decreases significantly. In combination with fluorescence spectroscopy, like single molecule Forster (or fluorescence) resonance energy transfer (FRET) whose detectable distance range is approximately 3-10 nm, we are able to observe nanometer fluctuations and internal conformational changes in a low-force regime. The possibility to place fluorescent labels at nearly any desired position and a sophisticated design of the experiment increases the amount of information that can be extracted in contrast to pure mechanical or fluorescence experiments. We demonstrate the applications of this method to various biological systems including: 1) to measure the effect of very low forces on the nanometer scale conformational transitions of the DNA four-way (Holliday) junction; 2) to dissect protein diffusion and dissociation mechanisms on single stranded DNA, 3) to calibrate FRET-based in-vivo force sensors and 4) to study mechanical unfolding of single proteins. The results could not have been obtained with fluorescence or force measurement alone, and clearly demonstrates the power and generality of our approach. Finally, we show that self-quenching of two identical fluorophores can be used to detect small conformational dynamics corresponding to sub-nanometer distance changes of single molecules in a FRET-insensitive short range (< 3 nm), extending the detectable distance range of our fluorescence-force spectroscopy method.

  15. Drag force scaling for penetration into granular media.

    PubMed

    Katsuragi, Hiroaki; Durian, Douglas J

    2013-05-01

    Impact dynamics is measured for spherical and cylindrical projectiles of many different densities dropped onto a variety non-cohesive granular media. The results are analyzed in terms of the material-dependent scaling of the inertial and frictional drag contributions to the total stopping force. The inertial drag force scales similar to that in fluids, except that it depends on the internal friction coefficient. The frictional drag force scales as the square-root of the density of granular medium and projectile, and hence cannot be explained by the combination of granular hydrostatic pressure and Coulomb friction law. The combined results provide an explanation for the previously observed penetration depth scaling. PMID:23767531

  16. 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.

  17. Nonlinear analysis of the forced response of structural elements

    NASA Technical Reports Server (NTRS)

    Nayfeh, A. H.; Mook, D. T.; Sridhar, S.

    1974-01-01

    A general procedure is presented for the nonlinear analysis of the forced response of structural elements to harmonic excitations. Internal resonances (i.e., modal interactions) are taken into account. All excitations are considered, with special consideration given to resonant excitations. The general procedure is applied to clamped-hinged beams. The results reveal that exciting a higher mode may lead to a larger response in a lower interacting mode, contrary to the results of linear analyses.

  18. Optimal lift force on vesicles near a compressible substrate

    NASA Astrophysics Data System (ADS)

    Beaucourt, J.; Biben, T.; Misbah, C.

    2004-08-01

    The dynamics of vesicles near a compressible substrate mimicking the glycocalyx layer of the internal part of blood vessels reveals the existence of an optimal lift force due to an elasto-hydrodynamic coupling between the counter flow and the deformation of the wall. An estimation of the order of magnitude of the optimal elastic modulus reveals that it lies within the physiological range, which may have important consequences for the dynamic of blood cells (leucocytes or red blood cells).

  19. Mechanical Force Sensing in Tissues

    PubMed Central

    Chanet, Soline; Martin, Adam C.

    2015-01-01

    Tissue size, shape, and organization reflect individual cell behaviors such as proliferation, shape change, and movement. Evidence suggests that mechanical signals operate in tandem with biochemical cues to properly coordinate cell behavior and pattern tissues. The objective of this chapter is to present recent evidence demonstrating that forces transmitted between cells act as signals that coordinate cell behavior across tissues. We first briefly summarize molecular and cellular mechanisms by which forces are sensed by cells with an emphasis on forces generated and transmitted by cytoskeletal networks. We then discuss evidence for these mechanisms operating in multicellular contexts to coordinate complex cell and tissue behaviors that occur during embryonic development: specifically growth and morphogenesis. PMID:25081624

  20. Photophoretic force on aggregate grains

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin S.; Kimery, Jesse B.; Wurm, Gerhard; de Beule, Caroline; Kuepper, Markus; Hyde, Truell W.

    2016-01-01

    The photophoretic force may impact planetary formation by selectively moving solid particles based on their composition and structure. This generates collision velocities between grains of different sizes and sorts the dust in protoplanetary discs by composition. This numerical simulation studied the photophoretic force acting on fractal dust aggregates of μm-scale radii. Results show that aggregates tend to have greater photophoretic drift velocities than spheres of similar mass or radii, though with a greater spread in the velocity. While the drift velocities of compact aggregates continue to increase as the aggregates grow larger in size, fluffy aggregates have drift velocities which are relatively constant with size. Aggregates formed from an initially polydisperse size distribution of dust grains behave differently from aggregates formed from a monodisperse population, having smaller drift velocities with directions which deviate substantially from the direction of illumination. Results agree with microgravity experiments which show the difference of photophoretic forces with aggregation state.