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1

Female labor force participation: an international perspective.  

PubMed

This article gives an international perspective in regard to female participation in the labor force. In most countries women contribute less than men toward the value of recorded production. Social environment, statistical inconsistencies and methods of recording labor all contribute to this inequity. In Britain for instance, women caring for the household duties are in some studies considered to be part of the labor force and in other studies they are not. Further, internationally, women often find themselves in casual, temporary, or seasonal work that goes unrecorded. Defining what "labor force participation" constitutes is a key starting point to any survey. At what age is one considered employable? What constitutes a person "actively seeking" employment? Economists often try to explain labor force participation rate by age, sex, race and income groups and use this information to cite trends. The income-leisure model theorizes that choice of work or non-work by women is based primarily upon wages for work vs. wages for non-work. This theory sees non-labor income exerting a negative influence. Empirical evidence, however, suggests that women will choose work if wages are good regardless of any non-work benefits. Because most men are permanently in the labor force, estimates of labor reserves and projections of supply focus mostly on women. International generalizations are often misleading since trends vary widely among countries. During the last 20 years the global female participation rate has remained almost constant, but this is misleading. The percentage of working women in industrial countries increased 10%; developing countries showed a decrease of 7%. Female rates are often tied closely to shifts in the overall economy, (e.g., a transition from an agricultural to an industrial economy often sees a drop in female labor because subsistence jobs are lost). Of course the ability of women to bear children and the social expectations regarding child care often play a role. It is common in western industrialized countries to see drops in female participation during childbearing years. Countries with the lowest female participation rates are those with strong religious views about women in society, (e.g., Catholic and Muslim countries). PMID:12283641

Psacharopoulos, G; Tzannatos, Z

1989-07-01

2

Participation in Armed Forces, National, and International Sports Activities.  

National Technical Information Service (NTIS)

The Directive reissues DoD Directive 1330.4, November 14, 1968; prescribes DoD policy concerning the participation of Armed Forces personnel in Armed Forces, national, and international sports competitions; establishes a Senior Military Sports Advisor, an...

J. Sass

1987-01-01

3

47 CFR 2.100 - International regulations in force.  

Code of Federal Regulations, 2013 CFR

...COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES...Allocation, Assignment, and Use of Radio Frequencies § 2.100 International regulations in force. The ITU Radio Regulations,...

2013-10-01

4

Self-force as probe of internal structure  

NASA Astrophysics Data System (ADS)

The self-force acting on a (scalar or electric) charge held in place outside a massive body contains information about the body’s composition, and can therefore be used as a probe of internal structure. We explore this theme by computing the (scalar or electromagnetic) self-force when the body is a spherical ball of perfect fluid in hydrostatic equilibrium, under the assumption that its rest-mass density and pressure are related by a polytropic equation of state. The body is strongly self-gravitating, and all computations are performed in exact general relativity. The dependence on internal structure is best revealed by expanding the self-force in powers of r-10, with r0 denoting the radial position of the charge outside the body. To the leading order, the self-force scales as r-30 and depends only on the square of the charge and the body’s mass; the leading self-force is universal. The dependence on internal structure is seen at the next order, r-50, through a structure factor that depends on the equation of state. We compute this structure factor for relativistic polytropes, and show that for a fixed mass, it increases linearly with the body’s radius in the case of the scalar self-force, and quadratically with the body’s radius in the case of the electromagnetic self-force. In both cases we find that for a fixed mass and radius, the self-force is smaller if the body is more centrally dense, and larger if the mass density is more uniformly distributed.

Isoyama, Soichiro; Poisson, Eric

2012-08-01

5

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

ERIC Educational Resources Information Center

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)

Gnezda-Smith, Nicole

1994-01-01

6

On forced temperature changes, internal variability, and the AMO  

NASA Astrophysics Data System (ADS)

estimate the low-frequency internal variability of Northern Hemisphere (NH) mean temperature using observed temperature variations, which include both forced and internal variability components, and several alternative model simulations of the (natural + anthropogenic) forced component alone. We then generate an ensemble of alternative historical temperature histories based on the statistics of the estimated internal variability. Using this ensemble, we show, first, that recent NH mean temperatures fall within the range of expected multidecadal variability. Using the synthetic temperature histories, we also show that certain procedures used in past studies to estimate internal variability, and in particular, an internal multidecadal oscillation termed the "Atlantic Multidecadal Oscillation" or "AMO", fail to isolate the true internal variability when it is a priori known. Such procedures yield an AMO signal with an inflated amplitude and biased phase, attributing some of the recent NH mean temperature rise to the AMO. The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming. Claims of multidecadal "stadium wave" patterns of variation across multiple climate indices are also shown to likely be an artifact of this flawed procedure for isolating putative climate oscillations.

Mann, Michael E.; Steinman, Byron A.; Miller, Sonya K.

2014-05-01

7

Internal flows and force matrices in axial flow inducers  

NASA Astrophysics Data System (ADS)

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

Bhattacharyya, Abhijit

1994-01-01

8

Forced wave motion with internal and boundary damping  

PubMed Central

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.

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

2012-01-01

9

Forced wave motion with internal and boundary damping  

NASA Astrophysics Data System (ADS)

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.

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

2012-01-01

10

North Atlantic Multidecadal SST Oscillation: External forcing versus internal variability  

NASA Astrophysics Data System (ADS)

The Atlantic Multi-decadal Oscillation (AMO) depicts the swings of North Atlantic basin-wide sea surface temperature (SST) between warm and cold phases on a multi-decadal time scale. The 20th Century instrumental record indicates a relative cold period in the beginning of the 20th Century, a warm period in the 1940s and 50s, another cold period in the 1970s and 80s, followed by the recent warming period. These multi-decadal temperature swings coincide with an upward warming trend throughout the 20th Century. One of the central questions concerning these changes is whether they were caused by human activities, including aerosols and greenhouse gas forcing, or whether they reflect some combination between natural factors and human activity. Using both observations and CMIP3 model simulations, we argue that the overall changes are due to the combination of natural multidecadal variability and anthropogenic forcing. We also examine the regional surface temperature, precipitation, and atmospheric circulation features associated with the externally forced and internal North Atlantic SST multidecadal variability using both 20th Century observations and CMIP3 model simulations of the 20th, 21st, and pre-industrial forcing.

Ting, Mingfang; Kushnir, Yochanan; Li, Cuihua

2014-05-01

11

Modeling Of Mercury's Exosphere With External And Internal Forcing  

NASA Astrophysics Data System (ADS)

Mercury's exosphere, most often seen in its sodium component, reveals an interesting interplay between external forcing and internal or surface processes. Several source processes have been proposed for the sodium and potassium exospheres of Mercury: photon-stimulated desorption, impact vaporization, ion-sputtering and thermal vaporization. The proposed loss processes are photoionization, with subsequent entrainment into the solar wind, and sticking or cold-trapping at the surface. A Monte Carlo code has been used to examine the response of the sodium exosphere of Mercury to internal and external forcing as it moves about the sun from perihelion to aphelion and returning to perihelion. One of the most controversial physical processes, the surface interaction, has been explored in the modeling for the first time. Both the sticking coefficient and the fraction of energy exchanged with the surface have been varied to determine their influence on the resulting exosphere. Radiation pressure is also calculated, along with feedback mechanisms. The ion flux capable of sputtering is obtained from our magnetosphere code (Mercury-adapted TH93 model) as a function of solar wind pressure and IMF parameters. The probability of occurrence of each magnetospheric configuration is computed from Helios particle and field data. The resulting atmosphere, surface concentration of volatiles, and maps of escaping atoms and the tail are shown. The modeled results are compared with data to constrain the sources and surface interaction. Expected atmospheres for Na, K, Ca and O will also be shown for a limited range of conditions. This research was funded by the NASA Planetary Atmospheres Program.

Killen, Rosemary M.; Crider, D. H.; Potter, A. E.; Sarantos, M.

2007-10-01

12

International Reference Ionosphere (IRI): Task Force Activity 2000  

NASA Technical Reports Server (NTRS)

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.

Bilitza, D.

2000-01-01

13

Modeling and control of multi-contact centers of pressure and internal forces in humanoid robots  

Microsoft Academic Search

This paper presents a methodology for the mod- eling and control of internal forces and moments produced during multi-contact interactions between humanoid robots and the environment. The approach is based on the virtual linkage model which provides a physical representation of the internal forces and moments acting between the various contacts. The forces acting at the contacts are decomposed into

Luis Sentis; Oussama Khatib

2009-01-01

14

High-frequency internal IC signal sampling using electrostatic force microscopy  

Microsoft Academic Search

An Electrostatic Force Microscopy technique for non-contact internal function and failure analysis of high-speed integrated circuits is described. Internal circuit voltages are measured by sensing the local electrostatic force on a small micromachined probe that is held in close proximity to the circuit test point. The force acting on the tip of the probe varies with the square of the

Z. Weng; G. E. Bridges; D. J. Thomson

2002-01-01

15

Foot forces during exercise on the International Space Station.  

PubMed

Long-duration exposure to microgravity has been shown to have detrimental effects on the human musculoskeletal system. To date, exercise countermeasures have been the primary approach to maintain bone and muscle mass and they have not been successful. Up until 2008, the three exercise countermeasure devices available on the International Space Station (ISS) were the treadmill with vibration isolation and stabilization (TVIS), the cycle ergometer with vibration isolation and stabilization (CEVIS), and the interim resistance exercise device (iRED). This article examines the available envelope of mechanical loads to the lower extremity that these exercise devices can generate based on direct in-shoe force measurements performed on the ISS. Four male crewmembers who flew on long-duration ISS missions participated in this study. In-shoe forces were recorded during activities designed to elicit maximum loads from the various exercise devices. Data from typical exercise sessions on Earth and on-orbit were also available for comparison. Maximum on-orbit single-leg loads from TVIS were 1.77 body weight (BW) while running at 8mph. The largest single-leg forces during resistance exercise were 0.72 BW during single-leg heel raises and 0.68 BW during double-leg squats. Forces during CEVIS exercise were small, approaching only 0.19 BW at 210W and 95RPM. We conclude that the three exercise devices studied were not able to elicit loads comparable to exercise on Earth, with the exception of CEVIS at its maximal setting. The decrements were, on average, 77% for walking, 75% for running, and 65% for squats when each device was at its maximum setting. Future developments must include an improved harness to apply higher gravity replacement loads during locomotor exercise and the provision of greater resistance exercise capability. The present data set provides a benchmark that will enable future researchers to judge whether or not the new generation of exercise countermeasures recently added to the ISS will address the need for greater loading. PMID:20728086

Genc, K O; Gopalakrishnan, R; Kuklis, M M; Maender, C C; Rice, A J; Bowersox, K D; Cavanagh, P R

2010-11-16

16

FRAX® International Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.  

PubMed

Osteoporosis is a serious worldwide epidemic. FRAX® is a web-based tool developed by the Sheffield WHO Collaborating Center team, that integrates clinical risk factors and femoral neck BMD and calculates the 10 year fracture probability in order to help health care professionals identify patients who need treatment. However, only 31 countries have a FRAX® calculator. In the absence of a FRAX® model for a particular country, it has been suggested to use a surrogate country for which the epidemiology of osteoporosis most closely approximates the index country. More specific recommendations for clinicians in these countries are not available. In North America, concerns have also been raised regarding the assumptions used to construct the US ethnic specific FRAX® calculators with respect to the correction factors applied to derive fracture probabilities in Blacks, Asians and Hispanics in comparison to Whites. In addition, questions were raised about calculating fracture risk in other ethnic groups e.g., Native Americans and First Canadians. The International Society for Clinical Densitometry (ISCD) in conjunction with the International Osteoporosis Foundation (IOF) assembled an international panel of experts that ultimately developed joint Official Positions of the ISCD and IOF advising clinicians regarding FRAX® usage. As part of the process, the charge of the FRAX® International Task Force was to review and synthesize data regarding geographic and race/ethnic variability in hip fractures, non-hip osteoporotic fractures, and make recommendations about the use of FRAX® in ethnic groups and countries without a FRAX® calculator. This synthesis was presented to the expert panel and constitutes the data on which the subsequent Official Positions are predicated. A summary of the International Task Force composition and charge is presented here. PMID:21810531

Cauley, Jane A; El-Hajj Fuleihan, Ghada; Luckey, Marjorie M

2011-01-01

17

The Virtual Linkage: A Model for Internal Forces in Multi-Grasp Manipulation  

Microsoft Academic Search

We propose a model to characterize internal forcesand moments during multi-grasp manipulation. Theproposed approach is based on construction of a physicalmodel, called the virtual linkage, which is a closedchain mechanism that represents the object being manipulated.Forces and moments applied at the grasppoints of this linkage cause joint forces and torquesat its actuators. When these actuators are subjectedto the opposing forces

David Williams; Oussama Khatib

1993-01-01

18

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

PubMed Central

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.

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

2013-01-01

19

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

PubMed Central

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.

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

2013-01-01

20

On the possible interaction between internal climate variability and forced climate change  

NASA Astrophysics Data System (ADS)

global warming hiatus does not necessarily mean a hiatus in anthropogenic greenhouse gas forcing and forced climate change (FCC). Here we show that both Atlantic Multidecadal Variability (AMV) and Pacific Decadal Oscillation (PDO) may cause fluctuations of the global mean surface air temperature (SAT) and hence alternately positive and negative trends on (inter)decadal time scales. However, the forced SAT change under a mean state due to greenhouse gas forcing does not depend on different phases of AMV and PDO, implying the effect of the FCC and internally generated climate variability can be linearly added up to the observed transient global mean SAT. On the other hand, the regional patterns of transient FCC do depend on the phases of the internal variability since the atmospheric and oceanic circulations can be affected by the different phases of the internal variability. Our results suggest a two-way interaction between internal variability and spatial patterns of FCC.

Lu, Jianhua; Hu, Aixue; Zeng, Zhen

2014-04-01

21

Minimizing distortion and internal forces in truss structures by simulated annealing  

NASA Technical Reports Server (NTRS)

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.

Kincaid, Rex K.; Padula, Sharon L.

1990-01-01

22

14th International Congress on Antiphospholipid Antibodies Task Force Report on Catastrophic Antiphospholipid Syndrome.  

PubMed

The 'Task Force on Catastrophic Antiphospholipid Syndrome (CAPS)' was developed on the occasion of the 14th International Congress on Antiphospholipid Antibodies. The objectives of this Task Force were to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of this condition in order to address recommendations for future research. This article summarizes the studies analyzed by the Task Force, its recommendations and the future research agenda. PMID:24657970

Cervera, Ricard; Rodríguez-Pintó, Ignasi; Colafrancesco, Serena; Conti, Fabrizio; Valesini, Guido; Rosário, Cristina; Agmon-Levin, Nancy; Shoenfeld, Yehuda; Ferrão, Claudia; Faria, Raquel; Vasconcelos, Carlos; Signorelli, Flavio; Espinosa, Gerard

2014-07-01

23

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

PubMed

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

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

2001-10-01

24

Design and implementation of an internal stress wave force balance in a shock tunnel  

Microsoft Academic Search

A stress wave internal force balance for the High Enthalpy Shock Tunnel Göttingen (HEG) of the German Aerospace Center (DLR)\\u000a to measure lift, pitching moment and drag was designed, calibrated and tested. The balance is designed to measure forces in\\u000a ground based test facilities with test times in the order of milliseconds on models additionally instrumented with surface\\u000a pressure and

M. J. Robinson; J. Martinez Schramm; K. Hannemann

25

Development and Testing of a New Three Component Short Duration Internal Force Balance for Heg  

Microsoft Academic Search

A new short duration internal force balance for the High Enthalpy Shock Tunnel G¨ottingen (HEG) to measure lift, pitching moment and drag has been designed, calibrated and tested. The balance is able to measures forces of the order of milliseconds on instrumented models from angles of attack of -40 to 20Æ. Tests were performed on a 303 mm long, 10Æ

M. J. Robinson; J. M. Schramm; K. Hannemann

2005-01-01

26

The representation of predictive force control and internal forward models: evidence from lesion studies and brain imaging  

Microsoft Academic Search

Force control on the basis of prediction avoids time delays from sensory feedback during motor performance. Thus, self-produced loads arising from gravitational and inertial forces during object manipulation can be compensated for by simultaneous anticipatory changes in grip force. It has been suggested that internal forward models predict the consequences of our movements, so that grip force can be programmed

J. Hermsdörfer; D. A. Nowak; A. Lee; K. Rost; D. Timmann; M. Mühlau; H. Boecker

2005-01-01

27

Study of the FIV exciting force on lower plenum structures of internal-pump-type BWRs  

SciTech Connect

In internal-pump-type boiling water reactors (BWRs), core coolant flows from the reactor internal pumps to structures in the lower plenum. The discharged flow from the pump is fed to such structures as the control rod guide tubes (CRGTs) and the in-core monitor guide tubes (ICMGTs), which causes flow-induced vibration (FIV) of these structures. The exciting force for the FIV around the lower structures. The exciting force for the FIV around the lower plenum structures is examined. Many pumps are installed in the annulus region between the reactor pressure vessel (RPV) and the core shroud, and the discharged flow is fed to the common lower plenum region. The discharged flow, which induces flow vibration, is strongly affected by the pump exit configurations. Flow-induced vibration exciting forces for identical CRGTs, located at different interpump discharge configurations, are examined. Water flow tests, using a one-fifth (360-deg) scale model, were performed to evaluate the exciting force on the lower plenum structures. Models of the reactor internal pump, the CRGT, and the ICMGT were installed. The flow path configuration was similar to that of an actual internal-pump-type BWR.

Yamamoto, Tetsuzo; Miyano, Hiroshi; Fujii, Takao

1990-01-01

28

A Critical Look at Climate Models: External Aerosol Forcing and Internal Feedback  

NASA Astrophysics Data System (ADS)

We examine the globally averaged surface temperature record, from 1900 to present, in terms of simulations presented within IPCC (2007) as well as the historical change in external factors that drive surface radiative forcing. We illustrate, as noted by Kiehl (2007) and Schwartz et al. (2007), that IPCC (2007) models have been tuned to match the observed temperature record via use of either substantial internal feedbacks to offset a large net cooling due to anthropogenic aerosols or else use of moderate internal feedbacks to offset modest aerosol cooling. We show that this tuning of climate models, while perhaps benign for our understanding of climate from 1900 to present, has considerable consequences for projections of future climate. The external forcing of climate by anthropogenic aerosols will be ameliorated during the next century due to air quality concerns; temperatures projected by models with large internal feedback diverge from temperatures projected by models with weak feedback as this aerosol forcing diminishes. We suggest uncertainties in the projection of future climate would be greatly reduced if the community could precisely define the net effect, on surface radiative forcing, of anthropogenic aerosols for the present-day world.

Salawitch, R. J.; Mascioli, N.; Canty, T. P.

2011-12-01

29

FRAX(®) Clinical Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.  

PubMed

The World Health Organization fracture risk assessment tool, FRAX(®), is an advance in clinical care that can assist in clinical decision-making. However, with increasing clinical utilization, numerous questions have arisen regarding how to best estimate fracture risk in an individual patient. Recognizing the need to assist clinicians in optimal use of FRAX(®), the International Osteoporosis Foundation (IOF) in conjunction with the International Society for Clinical Densitometry (ISCD) assembled an international panel of experts that ultimately developed joint Official Positions of the ISCD and IOF advising clinicians regarding FRAX(®) usage. As part of the process, the charge of the FRAX(®) Clinical Task Force was to review and synthesize data surrounding a number of recognized clinical risk factors including rheumatoid arthritis, smoking, alcohol, prior fracture, falls, bone turnover markers and glucocorticoid use. This synthesis was presented to the expert panel and constitutes the data on which the subsequent Official Positions are predicated. A summary of the Clinical Task Force composition and charge is presented here. PMID:21810522

McCloskey, Eugene V; Binkley, Neil

2011-01-01

30

The Application of Stiffness-Internal Force Adjustment Method in Widening and Reinforcement of Old Highway Bridges  

Microsoft Academic Search

Stiffness-internal force adjustment is a method which is applied in widening and reinforcement of old highway bridges. This method is that two new beams with larger rigidity are respectively built on both sides of the old bridge in order to make the old bridge unloading through the stiffness-internal force adjustment. This me- thod was successfully used for the reinforcement of

Zhi-xiang Zhou; Hong Xiang

2010-01-01

31

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

32

Optical tweezers reveal force plateau and internal friction in PEG-induced DNA condensation.  

PubMed

The simplified artificial environments in which highly complex biological systems are studied do not represent the crowded, dense, salty, and dynamic environment inside the living cell. Consequently, it is important to investigate the effect of crowding agents on DNA. We used a dual-trap optical tweezers instrument to perform force spectroscopy experiments at pull speeds ranging from 0.3 to 270 ?m/s on single dsDNA molecules in the presence of poly(ethylene glycol) (PEG) and monovalent salt. PEG of sizes 1,500 and 4,000 Da condensed DNA, and force-extension data contained a force plateau at approximately 1 pN. The level of the force plateau increased with increasing pull speed. During slow pulling the dissipated work increased linearly with pull speed. The calculated friction coefficient did not depend on amount of DNA incorporated in the condensate, indicating internal friction is independent of the condensate size. PEG300 had no effect on the dsDNA force-extension curve. The force plateau implies that condensation induced by crowding agents resembles condensation induced by multivalent cations. PMID:24477280

Ojala, Heikki; Ziedaite, Gabija; Wallin, Anders E; Bamford, Dennis H; Hæggström, Edward

2014-03-01

33

Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads  

Microsoft Academic Search

Despite the well-recognized role of lifting in back injuries, the relative biomechanical merits of squat versus stoop lifting\\u000a remain controversial. In vivo kinematics measurements and model studies are combined to estimate trunk muscle forces and internal\\u000a spinal loads under dynamic squat and stoop lifts with and without load in hands. Measurements were performed on healthy subjects\\u000a to collect segmental rotations

Babak Bazrgari; Aboulfazl Shirazi-Adl; Navid Arjmand

2007-01-01

34

Force field effects on cerebellar Purkinje cell discharge with implications for internal models.  

PubMed

The cerebellum has been hypothesized to provide internal models for limb movement control. If the cerebellum is the site of an inverse dynamics model, then cerebellar neural activity should signal limb dynamics and be coupled to arm muscle activity. To address this, we recorded from 166 task-related Purkinje cells in two monkeys performing circular manual tracking under varying viscous and elastic loads. Hand forces and arm muscle activity increased with the load, and their spatial tuning differed markedly between the viscous and elastic fields. In contrast, the simple spike firing of 91.0% of the Purkinje cells was not significantly modulated by the force nor was their spatial tuning affected. For the 15 cells with a significant force effect, changes were small and isolated. These results do not support the hypothesis that Purkinje cells represent the output of an inverse dynamics model of the arm. Instead these neurons provide a kinematic representation of arm movements. PMID:17028585

Pasalar, S; Roitman, A V; Durfee, W K; Ebner, T J

2006-11-01

35

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

NASA Astrophysics Data System (ADS)

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

Mikšovský, Ji?í; Pišoft, Petr

2014-05-01

36

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

37

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

NASA Technical Reports Server (NTRS)

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.

1998-01-01

38

Cost Assessment and Validation Task Force on the International Space Station  

NASA Technical Reports Server (NTRS)

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.

1998-01-01

39

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

40

Distinguishing the effects of internal and forced atmospheric variability in climate networks  

NASA Astrophysics Data System (ADS)

The fact that the climate on the earth is a highly complex dynamical system is well-known. In the last few decades great deal of effort has been focused on understanding how climate phenomena in one geographical region affects the climate of other regions. Complex networks are a powerful framework for identifying climate interdependencies. To further exploit the knowledge of the links uncovered via the network analysis (for, e.g., improvements in prediction), a good understanding of the physical mechanisms underlying these links is required. Here we focus on understanding the role of atmospheric variability, and construct climate networks representing internal and forced variability using the output of an ensemble of AGCM runs. A main strength of our work is that we construct the networks using MIOP (mutual information computed from ordinal patterns), which allows the separation of intraseasonal, intra-annual and interannual timescales. This gives further insight to the analysis of climatological data. The connectivity of these networks allows us to assess the influence of two main indices, NINO3.4 - one of the indices used to describe ENSO (El Niño-Southern oscillation) - and of the North Atlantic Oscillation (NAO), by calculating the networks from time series where these indices were linearly removed. A main result of our analysis is that the connectivity of the forced variability network is heavily affected by "El Niño": removing the NINO3.4 index yields a general loss of connectivity; even teleconnections between regions far away from the equatorial Pacific Ocean are lost, suggesting that these regions are not directly linked, but rather, are indirectly interconnected via El Niño, particularly at interannual timescales. On the contrary, on the internal variability network - independent of sea surface temperature (SST) forcing - the links connecting the Labrador Sea with the rest of the world are found to be significantly affected by NAO, with a maximum at intra-annual timescales. While the strongest non-local links found are those forced by the ocean, the presence of teleconnections due to internal atmospheric variability is also shown.

Deza, J. I.; Masoller, C.; Barreiro, M.

2014-05-01

41

Development and Testing of a New Three Component Short Duration Internal Force Balance for Heg  

NASA Astrophysics Data System (ADS)

A new short duration internal force balance for the High Enthalpy Shock Tunnel G¨ottingen (HEG) to measure lift, pitching moment and drag has been designed, calibrated and tested. The balance is able to measures forces of the order of milliseconds on instrumented models from angles of attack of -40 to 20Æ. Tests were performed on a 303 mm long, 10Æ half angle blunt cone at angles of attack from 0 to -20Æ. The tests were conducted at two test conditions with a Mach number of 7.8 and total enthalpies of 3.0 and 3.5 MJ/kg. At 0Æ angle of attack, the measured axial coefficient was recovered to within 6% when compared to computational fluid dynamic (CFD) simulations. A constant axial (drag) coefficient of 0.10 was obtained for the conical model over dynamic pressures ranging from 30 to 70 kPa. As the angle of attack was varied from 0 to -20Æ, the axial coefficient increased to 0.24, the normal coefficient decreased to -0.57 and the pitching moment coefficient (about the model tip) increased to 0.38. At -10Æ, the axial and normal coefficients were within 6% and 9% respectively of CFD predictions while the centre of pressure (based on chord length) was within 2%. Key words: Short duration force measurement; Hypersonic; Blunt cone; Shock tunnel.

Robinson, M. J.; Schramm, J. M.; Hannemann, K.

2005-02-01

42

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

PubMed

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

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

43

Neural basis for the processes that underlie visually guided and internally guided force control in humans.  

PubMed

Despite an intricate understanding of the neural mechanisms underlying visual and motor systems, it is not completely understood in which brain regions humans transfer visual information into motor commands. Furthermore, in the absence of visual information, the retrieval process for motor memory information remains unclear. We report an investigation where visuomotor and motor memory processes were separated from only visual and only motor activation. Subjects produced precision grip force during a functional MRI (fMRI) study that included four conditions: rest, grip force with visual feedback, grip force without visual feedback, and visual feedback only. Statistical and subtractive logic analyses segregated the functional process maps. There were three important observations. First, along with the well-established parietal and premotor cortical network, the anterior prefrontal cortex, putamen, ventral thalamus, lateral cerebellum, intermediate cerebellum, and the dentate nucleus were directly involved in the visuomotor transformation process. This activation occurred despite controlling for the visual input and motor output. Second, a detailed topographic orientation of visuomotor to motor/sensory activity was mapped for the premotor cortex, parietal cortex, and the cerebellum. Third, the retrieval of motor memory information was isolated in the dorsolateral prefrontal cortex, ventral prefrontal cortex, and anterior cingulate. The motor memory process did not extend to the supplementary motor area (SMA) and the basal ganglia. These findings provide evidence in humans for a model where a distributed network extends over cortical and subcortical regions to control the visuomotor transformation process used during visually guided tasks. In contrast, a localized network in the prefrontal cortex retrieves force output from memory during internally guided actions. PMID:12840082

Vaillancourt, David E; Thulborn, Keith R; Corcos, Daniel M

2003-11-01

44

Role of the Basal Ganglia and Frontal Cortex in Selecting and Producing Internally Guided Force Pulses  

PubMed Central

The basal ganglia comprise a crucial circuit involved in force production and force selection, but the specific role of each nucleus to the production of force pulses and the selection of pulses of different force amplitudes remains unknown. We conducted an fMRI study in which participants produced force using a precision grip while a) holding a steady-state force, b) performing a series of force pulses with similar amplitude, and c) selecting force pulses of different amplitude. Region of interest analyses were conducted in the basal ganglia and frontal cortex to compare percent signal change during force pulse versus steady-state force production, and compare force amplitude selection to force production when selection of force amplitude was not present. There were three novel findings in the basal ganglia. First, the caudate nucleus increased activation during the selection of different force amplitudes when compared to producing a series of similar force pulses. Second, GPi, STN, and posterior putamen increased activation during the production of similar force amplitudes when compared to holding a steady-state force, and maintained similar activation during the production of different force amplitudes in which force selection was required. Third, GPe and anterior putamen had increased activation during the production of similar force pulses and further increased activation during the selection of different force pulses. These findings suggest that anterior basal ganglia nuclei are involved in selecting the amplitude of force contractions and posterior basal ganglia nuclei regulate basic aspects of dynamic force pulse production.

Vaillancourt, David E.; Yu, Hong; Mayka, Mary A.; Corcos, Daniel M.

2007-01-01

45

Forces  

NSDL National Science Digital Library

The representation depicts what forces are and how they can change the motion and shape of objects in an animated slide show. This resource also includes an interactive test and review of the material, and can be downloaded for offline use.

46

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

PubMed

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

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

47

Investigating the Internal Structure of Individual Aerosol Particles Using Atomic Force and Raman Microscopies  

NASA Astrophysics Data System (ADS)

We have used Atomic Force Microscopy (AFM) and Raman Microscopy to probe aerosol internal structures in order to understand the optical properties of aerosols composed of mixtures of organic and inorganic components. While AFM gives only topographical information about the particles, indirect chemical information can be obtained by using substrates with different surface properties. With Raman microscopy, chemical signatures of the components of the aerosol are obtained, but we have limited spatial resolution. We have explored the use of these two techniques to look at aerosol internal structure using a range of different model aerosols composed of mixtures of ammonium sulfate with organic compounds of various solubilities such as sucrose, succinic acid, and palmitic acid. At the extremes of solubility, AFM provides suitable information for interpreting aerosol microstructure. For example, AFM clearly shows the presence of core-shell structures for aerosol particles composed of palmitic acid and ammonium sulfate, while the results for aerosol particles composed of succinic acid and ammonium sulfate are more difficult to interpret. Information about size and shape can be obtained when hydrophilic particles are impacted on hydrophobic substrates and vise versa. With Raman microscopy, core-shell structures were readily identified for ammonium sulfate with palmitic acid or succinic acid coatings. For the case of succinic acid and ammonium sulfate mixtures, we are using microscopy results to aid in interpreting the refractive indices we retrieved from cavity ring-down studies.

Freedman, M. A.; Baustian, K. J.; Wise, M. E.; Tolbert, M. A.

2009-12-01

48

Late Pliocene to Pleistocene sensitivity of the Greenland Ice Sheet in response to external forcing and internal feedbacks  

Microsoft Academic Search

The timing and nature of ice sheet variations on Greenland over the last ?5 million years remain largely uncertain. Here,\\u000a we use a coupled climate-vegetation-ice sheet model to determine the climatic sensitivity of Greenland to combined sets of\\u000a external forcings and internal feedbacks operating on glacial-interglacial timescales. In particular, we assess the role of\\u000a atmospheric pCO2, orbital forcing, and vegetation dynamics

Sebastian J. Koenig; Robert M. DeConto; David Pollard

49

Late Pliocene to Pleistocene sensitivity of the Greenland Ice Sheet in response to external forcing and internal feedbacks  

Microsoft Academic Search

The timing and nature of ice sheet variations on Greenland over the last ˜5 million years remain largely uncertain. Here, we use a coupled climate-vegetation-ice sheet model to determine the climatic sensitivity of Greenland to combined sets of external forcings and internal feedbacks operating on glacial-interglacial timescales. In particular, we assess the role of atmospheric pCO2, orbital forcing, and vegetation

Sebastian J. Koenig; Robert M. Deconto; David Pollard

2011-01-01

50

The everyday violence of forced displacement : community, memory and identity politics among Kurdish internal forced migrants in Turkey  

Microsoft Academic Search

Kurds in Turkey: the everyday violence of their forced displacement. Roughly fifteen years ago, more than one million Kurds were forcibly displaced from their villages in Southeast Turkey, mostly by Turkish security troops, who were engaged in a violent struggle with the PKK, an armed organization that strives for Kurdish self-rule. Large numbers of displaced Kurds migrated to cities in

M. T. Geerse

2011-01-01

51

Treat-to-target in systemic lupus erythematosus: recommendations from an international task force.  

PubMed

The principle of treating-to-target has been successfully applied to many diseases outside rheumatology and more recently to rheumatoid arthritis. Identifying appropriate therapeutic targets and pursuing these systematically has led to improved care for patients with these diseases and useful guidance for healthcare providers and administrators. Thus, an initiative to evaluate possible therapeutic targets and develop treat-to-target guidance was believed to be highly appropriate in the management of systemic lupus erythematosus (SLE) patients as well. Specialists in rheumatology, nephrology, dermatology, internal medicine and clinical immunology, and a patient representative, contributed to this initiative. The majority convened on three occasions in 2012-2013. Twelve topics of critical importance were identified and a systematic literature review was performed. The results were condensed and reformulated as recommendations, discussed, modified and voted upon. The finalised bullet points were analysed for degree of agreement among the task force. The Oxford Centre level of evidence (LoE, corresponding to the research questions) and grade of recommendation (GoR) were determined for each recommendation. The 12 systematic literature searches and their summaries led to 11 recommendations. Prominent features of these recommendations are targeting remission, preventing damage and improving quality of life. LoE and GoR of the recommendations were variable but agreement was >0.9 in each case. An extensive research agenda was identified, and four overarching principles were also agreed upon. Treat-to-target-in-SLE (T2T/SLE) recommendations were developed by a large task force of multispecialty experts and a patient representative. It is anticipated that 'treating-to-target' can and will be applicable to the care of patients with SLE. PMID:24739325

van Vollenhoven, Ronald F; Mosca, Marta; Bertsias, George; Isenberg, David; Kuhn, Annegret; Lerstrøm, Kirsten; Aringer, Martin; Bootsma, Hendrika; Boumpas, Dimitrios; Bruce, Ian N; Cervera, Ricard; Clarke, Ann; Costedoat-Chalumeau, Nathalie; Czirják, László; Derksen, Ronald; Dörner, Thomas; Gordon, Caroline; Graninger, Winfried; Houssiau, Frédéric; Inanc, Murat; Jacobsen, Søren; Jayne, David; Jedryka-Goral, Anna; Levitsky, Adrian; Levy, Roger; Mariette, Xavier; Morand, Eric; Navarra, Sandra; Neumann, Irmgard; Rahman, Anisur; Rovensky, Jozef; Smolen, Josef; Vasconcelos, Carlos; Voskuyl, Alexandre; Voss, Anne; Zakharova, Helena; Zoma, Asad; Schneider, Matthias

2014-06-01

52

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

PubMed Central

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.

Monclair, Tom; Brodeur, Garrett M.; Ambros, Peter F.; Brisse, Herve 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

53

Rapid generation of high-frequency internal waves beneath a wind and wave forced oceanic surface mixed layer  

Microsoft Academic Search

High-frequency internal waves generated by Langmuir motions over stratified water may be an important source of turbulent mixing below the surface mixed layer. Large eddy simulations of a developing mixed layer and inertial current are employed to investigate this phenomena. Uniform surface wind stress and parallel Stokes drift wave forcing rapidly establishes a turbulent mixed-layer flow, which (as the inertial

Jeff A. Polton; Jerome A. Smith; J. A. MacKinnon; Andrés E. Tejada-Martínez

2008-01-01

54

Internal development of vegetative buds of Norway spruce trees in relation to accumulated chilling and forcing temperatures.  

PubMed

The timing of budburst of temperate trees is known to be controlled by complicated interactions of temperature and photoperiod. To improve the phenological models of budburst, better knowledge of the internal bud development preceding budburst in relation to environmental cues is needed. We studied the effect of accumulated chilling and forcing temperatures on the internal development of vegetative buds preceding budburst in Norway spruce [Picea abies (L.) Karst.]. Branches from 17-year-old trees of southern Finnish origin were transferred eight times at 1- to 2-week intervals from October to December 2007 from the field at Punkaharju (61°48'N, 29°20'E) to the greenhouse with forcing conditions (day length 12?h, +20?°C). After seven different durations of forcing, the developmental phase and primordial shoot growth of the buds were analysed at the stereomicroscopic level. Air temperature was recorded hourly throughout the study period. The accumulated chilling unit sum had a significant effect on the temperature sum that was required to attain a certain developmental phase; a higher amount of chilling required a lower amount of forcing. The variation in the rate of development of different buds within each sample branch in relation to the chilling unit and forcing temperature sum was low. Regarding primordial shoot growth, there was also an inverse relation between accumulated chilling and forcing, i.e., a higher accumulated chilling unit sum before forcing required a lower temperature sum to initiate primordial shoot growth and resulted in a stronger effect of accumulated forcing. A second-order regression model with an interaction of chilling and forcing explained the variation of primordial shoot growth with high precision (R(2)?=?0.88). However, further studies are required to determine the final parameter values to be used in phenological modelling. PMID:24876293

Viherä-Aarnio, Anneli; Sutinen, Sirkka; Partanen, Jouni; Häkkinen, Risto

2014-05-01

55

Effects of focal hand dystonia on visually guided and internally guided force control  

PubMed Central

Background A fundamental feature underlying many movement disorders is increased variability in the motor response. Despite abnormalities of grip force control in people with dystonia, it is not clear whether dystonia is also associated with increased variability in force output and whether force variability in dystonia is affected by the presence or absence of visual feedback. Objective To examine force variability in 16 patients with writer's cramp and 16 matched controls. Methods The variability of force output at the wrist under conditions of both vision and no vision was examined. The underlying frequency structure of the force signal was also compared across groups. Participants produced isometric wrist flexion to targets at 25% and 50% of their maximum voluntary contraction strength under conditions of both vision and no vision. Results Similar levels of force variability were observed in patients with dystonia and controls at the lower force levels, but patients with dystonia were less variable in their force output than controls at the higher force level. This reduction in variability in people with dystonia at 50% maximum voluntary contraction was not affected by vision. Although a similar dominant frequency in force output was observed in people with dystonia and controls, a reduced variability in the group with dystonia at the higher force level was due to reduced power in the 0–4?Hz frequency bin. Conclusions The first evidence of a movement disorder with reduced variability is provided. The findings are compatible with a model of dystonia, which includes reduced cortical activation in response to sensory input from the periphery and reduced flexibility in motor output.

Prodoehl, J; Corcos, D M; Vaillancourt, D E

2006-01-01

56

Force-induced melting of DNA-evidence for peeling and internal melting from force spectra on short synthetic duplex sequences.  

PubMed

Overstretching of DNA occurs at about 60-70 pN when a torsionally unconstrained double-stranded DNA molecule is stretched by its ends. During the transition, the contour length increases by up to 70% without complete strand dissociation. Three mechanisms are thought to be involved: force-induced melting into single-stranded DNA where either one or both strands carry the tension, or a B-to-S transition into a longer, still base-paired conformation. We stretch sequence-designed oligonucleotides in an effort to isolate the three processes, focusing on force-induced melting. By introducing site-specific inter-strand cross-links in one or both ends of a 64 bp AT-rich duplex we could repeatedly follow the two melting processes at 5 mM and 1 M monovalent salt. We find that when one end is sealed the AT-rich sequence undergoes peeling exhibiting hysteresis at low and high salt. When both ends are sealed the AT sequence instead undergoes internal melting. Thirdly, the peeling melting is studied in a composite oligonucleotide where the same AT-rich sequence is concatenated to a GC-rich sequence known to undergo a B-to-S transition rather than melting. The construct then first melts in the AT-rich part followed at higher forces by a B-to-S transition in the GC-part, indicating that DNA overstretching modes are additive. PMID:24838568

Bosaeus, Niklas; El-Sagheer, Afaf H; Brown, Tom; Akerman, Björn; Nordén, Bengt

2014-08-01

57

Force-induced melting of DNA--evidence for peeling and internal melting from force spectra on short synthetic duplex sequences  

PubMed Central

Overstretching of DNA occurs at about 60–70 pN when a torsionally unconstrained double-stranded DNA molecule is stretched by its ends. During the transition, the contour length increases by up to 70% without complete strand dissociation. Three mechanisms are thought to be involved: force-induced melting into single-stranded DNA where either one or both strands carry the tension, or a B-to-S transition into a longer, still base-paired conformation. We stretch sequence-designed oligonucleotides in an effort to isolate the three processes, focusing on force-induced melting. By introducing site-specific inter-strand cross-links in one or both ends of a 64 bp AT-rich duplex we could repeatedly follow the two melting processes at 5 mM and 1 M monovalent salt. We find that when one end is sealed the AT-rich sequence undergoes peeling exhibiting hysteresis at low and high salt. When both ends are sealed the AT sequence instead undergoes internal melting. Thirdly, the peeling melting is studied in a composite oligonucleotide where the same AT-rich sequence is concatenated to a GC-rich sequence known to undergo a B-to-S transition rather than melting. The construct then first melts in the AT-rich part followed at higher forces by a B-to-S transition in the GC-part, indicating that DNA overstretching modes are additive.

Bosaeus, Niklas; El-Sagheer, Afaf H.; Brown, Tom; Akerman, Bjorn; Norden, Bengt

2014-01-01

58

World gas supply and demand: 1980-2020. Based on a study by the International Gas Union Force II  

Microsoft Academic Search

If world oil prices and economic growth rates rise moderately (2%\\/yr) as assumed by the International Gas Union's Task Force II, world natural gas demand could increase from 1980's level of 52 quadrillion Btu to 74 quads by 1990 and 90 quads by 2000. Gas demand growth rates will peak at 4.5%\\/yr during 1980-85, then fall to 3.3%\\/yr in 1985-90,

L. W. Fish; R. B. Kalisch; J. L. Wingenroth; S. R. Kirk; J. F. Meeder

1982-01-01

59

FRAX(®) Bone Mineral Density Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.  

PubMed

FRAX(®) is a fracture risk assessment algorithm developed by the World Health Organization in cooperation with other medical organizations and societies. Using easily available clinical information and femoral neck bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), when available, FRAX(®) is used to predict the 10-year probability of hip fracture and major osteoporotic fracture. These values may be included in country specific guidelines to aid clinicians in determining when fracture risk is sufficiently high that the patient is likely to benefit from pharmacological therapy to reduce that risk. Since the introduction of FRAX(®) into clinical practice, many practical clinical questions have arisen regarding its use. To address such questions, the International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundations (IOF) assigned task forces to review the best available medical evidence and make recommendations for optimal use of FRAX(®) in clinical practice. Questions were identified and divided into three general categories. A task force was assigned to investigating the medical evidence in each category and developing clinically useful recommendations. The BMD Task Force addressed issues that included the potential use of skeletal sites other than the femoral neck, the use of technologies other than DXA, and the deletion or addition of clinical data for FRAX(®) input. The evidence and recommendations were presented to a panel of experts at the ISCD-IOF FRAX(®) Position Development Conference, resulting in the development of ISCD-IOF Official Positions addressing FRAX(®)-related issues. PMID:21810529

Lewiecki, E Michael; Compston, Juliet E; Miller, Paul D; Adachi, Jonathan D; Adams, Judith E; Leslie, William D; Kanis, John A

2011-01-01

60

Analysis of object-stability and internal force in robotic contact tasks  

Microsoft Academic Search

The stability of an object manipulated by multiple robots (serial-link or wire-driven mechanisms) in contact tasks is investigated. We show that resultant force\\/moment applicable to the object through the contacts is represented as a polyhedral convex region in force\\/moment space. Then we propose a stability measure and a method of calculating it approximately by linear programming technique. We also present

Yusuke Maeda; Yasumichi Aiyama; Tamio Arai; Taiga Ozawa

1996-01-01

61

Driving forces behind African transboundary water law: internal, external, and implications  

Microsoft Academic Search

While it may be commonly assumed that transboundary water law is driven by water related concerns revealed in the texts of international agreements, external, textually invisible factors often influence the formation and realization of treaties as well. Using both textual and contextual analysis, this study provides an initial assessment of the drivers of international water law in Africa's post-colonial period.

Jonathan Lautze; Mark Giordano; Maelis Borghese

62

Bilingual Interns' Barriers to Becoming Teachers: At What Cost Do We Diversify the Teaching Force?  

ERIC Educational Resources Information Center

A critical ethnography of three Mexican American bilingual interns examines the barriers that minority individuals face in gaining licensure to teach. These include a salary reduction, a stressful workload, teacher exams, inability to use their bilingual education skills, and mentors with no experience in bilingual education or at the interns'…

Waldschmidt, Eileen Dugan

2002-01-01

63

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

ERIC Educational Resources Information Center

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

Brown, Lorraine

2009-01-01

64

International education: a force for peace and cross?cultural understanding?  

Microsoft Academic Search

This paper discusses the notion that the international sojourn has the potential to transform sojourners into cultural mediators who carry the power to improve global relations. A year?long ethnographic study of the adjustment experiences of international postgraduate students in England revealed a universal early enthusiasm for cross?cultural contact that was matched by a widespread adoption of segregated patterns of interacting.

Lorraine Brown

2009-01-01

65

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

NASA Astrophysics Data System (ADS)

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.

Reichling, Michael

2004-02-01

66

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

ERIC Educational Resources Information Center

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

Public Personnel Management, 2000

2000-01-01

67

Military Campaign Against Gangs: Internal Security Operations in the United States by Active Duty Forces.  

National Technical Information Service (NTIS)

This study examines the historical precedents and the laws that allow federal troops to combat domestic enemies, the current environment that may call for the use of active duty forces, and a model that can be used to deal with domestic disturbances withi...

D. R. Hogg

1993-01-01

68

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

Microsoft Academic Search

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

M. J. Werle; V. N. Vasta

1982-01-01

69

Conjugate forced convection flow past a circular cylinder with internal heat generation in a porous medium  

Microsoft Academic Search

Purpose – The aim is to determine the effect of different conductivity ratios on forced convection past a circular cylinder embedded in a porous medium, where the solid cylinder forms a uniform heat source. Design\\/methodology\\/approach – The authors employ an unsteady finite difference method to obtain the resulting steady-state solutions. Interface conditions are applied using the fictitious point method. Findings

Nur F. Abd Kadir; D. A. S. Rees; Ioan Pop

2008-01-01

70

Hazard Evaluation and Technical Assistance Report No. TA 78-30, International Center of Environmental Safety, Holloman Air Force Base, Alamogordo, New Mexico.  

National Technical Information Service (NTIS)

Animal health records, and those of current and former employees at the International Center of Environmental Safety (ICES) at Holloman Air Force Base, Alamogordo, New Mexico were reviewed in response to a request from OSHA Region VI concerning potential ...

W. J. Martone B. D. Politi

1979-01-01

71

The role of forcing and internal dynamics in explaining the "Medieval Climate Anomaly"  

NASA Astrophysics Data System (ADS)

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.

Goosse, Hugues; Crespin, Elisabeth; Dubinkina, Svetlana; Loutre, Marie-France; Mann, Michael E.; Renssen, Hans; Sallaz-Damaz, Yoann; Shindell, Drew

2012-12-01

72

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

73

Magnetic force microscopy/current contrast imaging: A new technique for internal current probing of ICs  

SciTech Connect

This invited paper describes recently reported work on the application of magnetic force microscopy (MFM) to image currents in IC conductors [1]. A computer model for MFM imaging of IC currents and experimental results demonstrating the ability to determine current direction and magnitude with a resolution of {approximately} 1 mA dc and {approximately} 1 {mu}A ac are presented. The physics of MFM signal generation and applications to current imaging and measurement are described.

Campbell, A.N.; Cole, E.I. Jr.; Dodd, B.A.; Anderson, R.E.

1993-09-01

74

Selection and Control of Object Motion and Internal Force for Grasping/Manipulation by Multi-fingered Robot Hands with Constrained DOF  

NASA Astrophysics Data System (ADS)

This paper is concerned with a control design method for multi-fingered robot hands, whose degrees of freedom (DOF) are not enough to control all of the components of the object motion and the internal force. In the control design of the multi-fingered robot hands, controllers are usually designed for the variables with respect to the object motion and the internal force, under the assumption that the systems have enough DOF to control all the components of them. However, if we consider the systems with fewer DOF, although the control variables directly linked to the components of the object motion and the internal force will be preferable for the grasping/manipulation tasks, control design methodology to meet such requirements has not been established yet. In this paper, we consider the systems whose DOF are not enough to control all of the components of the object motion and the internal force, and propose a control design method whose control variables are directly linked to the components of the object motion and the internal force. The control variables can be specified as functions of the object motion and the internal force directly, and a linearizing compensator for the variables is derived. A numerical example of a robot hand with interlocking joints is shown to prove effectiveness of the proposed method.

Nagase, Kenji; Fujita, Kenji

75

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

SciTech Connect

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.

Pilat, Joseph F [Los Alamos National Laboratory

2010-12-08

76

Vibrational spectra of trimethyl gallium species in relation to the force field and methyl group internal rotation  

NASA Astrophysics Data System (ADS)

Infrared and Raman spectra are reported for Ga(CH 3) 3, Ga(CD 3) 3 and Ga(CHD 2) 3 in the gas phase. These were also examined in the i.r. spectrum in the solid phase at 78 K. The new Raman spectra of the CHD 2 species strongly support earlier i.r. evidence for CH force constant variation during free internal rotation of the methyl groups, from the presence of two bands at 2940 (vs) and 2922 cm -1 (w) identified as due to ? avis and ? †is respectively. The observed a' and e' frequencies of the d0 and d9 species are used to obtain a force field in which three interaction constants are well defined. The best value of the Ga-C stretching force constant is 2.356(28) mdyn Å -1. In the crystal phase at 78 K, the e' modes due to ? s Me and ? as GaC 3 are split, indicating a site group symmetry lower than C3. Gallium and carbon isotope frequency shifts are predicted.

McKean, D. C.; McQuillan, G. P.; Duncan, J. L.; Shephard, N.; Munro, B.; Fawcett, V.; Edwards, H. G. M.

77

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

NASA Technical Reports Server (NTRS)

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.

Paterson, R. W.

1982-01-01

78

Anisotropic plastic deformation of extruded aluminum alloy tube under axial forces and internal pressure  

Microsoft Academic Search

The anisotropic plastic deformation behavior of extruded 5000 series aluminum alloy tubes, A5154-H112, of 76 mm outer diameter and 3.9 mm wall thickness is investigated, using a servo-controlled tension-internal pressure testing machine. This machine is capable of applying arbitrary stress or strain paths to a tubular specimen using an electrical, closed-loop control system. Detailed measurements were made of the initial

T. Kuwabara; K. Yoshida; K. Narihara; S. Takahashi

2005-01-01

79

Failure of circular cylindrical shells formed from an orthotropic material, weakened by a longitudinal crack, and subjected to static loading by an axial force and internal pressure  

Microsoft Academic Search

References in which an alternate scheme of loading by internal pressure is preferentially analyzed are devoted to investigation of the limiting state of cracked shells fabricated from isotropic materials. Bastun and Galatenko and Bastun and Hretinin investigated the bearing capacity of circular cylindrical shells with a longitudinal crack under a combined static loading by an axial force and internal pressure.

V. N. Bastun

1995-01-01

80

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

PubMed Central

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.

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

81

New internal structure of spider dragline silk revealed by atomic force microscopy.  

PubMed Central

Atomic force microscopy was used to study the three-dimensional nanometer-scale structure of the dragline silk of Nephila clavipes from microtomed sections of the silk. Contrary to a previously proposed model of randomly distributed protein crystallites interspersed in amorphous regions, a highly organized skin-core structure of the fiber was observed. The skin appeared to be thin with no discernible distinct features. The core consists of pleated fibril-like structures, which are arranged in two concentric cylinders. Upon stretching, the pleats were smoothed out substantially. The mechanical properties of spider silk can quite straightforwardly be related to the newly observed structures. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4

Li, S F; McGhie, A J; Tang, S L

1994-01-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

83

Lobe Shifting in the Gulf of Papua: Internal or External Forcing?  

NASA Astrophysics Data System (ADS)

Recently acquired CHIRP data from the Gulf of Papua (GoP) reveals that the modern clinoform is inherently three- dimensional across a variety of scales. Three depositional lobes are identified in the mid-shelf region of the GoP; a central lobe that is downlapped by younger northern and southern lobes. While the depocenter shift and infilling of available accommodation within the central lobe appears to be predominantly controlled by depositional processes and stacking patterns (autocyclic forces), the marked shift in deposition away from the central lobe to the northern and southern lobes (~60-80 km) is difficult to explain by depositional processes alone. The northern and southern lobes downlap onto the central lobe with no evidence of interfingering, which suggests an abrupt shift in the loci of deposition away from the central lobe. Radiocarbon dates from the youngest units in the central lobe suggest this shift occurred after 2 ka and thus it is difficult to invoke eustatic sea level fluctuations to explain this marked shift in deposition. Sediment rerouting or oceanographic changes may account for this dramatic shift in the depositional lobes. High-resolution mapping of the three dimensional architecture of shelf building clinothems has provided new insight into sediment dispersal systems that is the critical first step to determine whether GoP lobe switching is a stochastic (autocyclic) or externally driven (allocyclic) process.

Johnstone, E. A.; Driscoll, N. W.; Slingerland, R.; Milliman, J. D.; Babcock, J.

2007-12-01

84

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

PubMed Central

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.

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, Desiree

2010-01-01

85

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

PubMed Central

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.

2013-01-01

86

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

NASA Astrophysics Data System (ADS)

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

Schwarz, Udo

2005-03-01

87

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)

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

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

1998-08-01

88

Quartic canonical force field in curvilinear internal coordinates for XY3 (D 3h ) molecules. The case of the BH 3 molecule.  

PubMed

Using the canonical force field theory, expressions of quadratic, cubic, and quartic canonical force constants are obtained for XY3 (D 3h ) molecules in curvilinear redundant coordinates, i.e., simple valence internal coordinates (VICs), in terms of force constants in normal coordinates and in independent symmetry coordinates. To carry out this task, it was previously necessary to obtain for the first time the non-linear redundancy relation and the corresponding orthogonal projection onto the pure vibrational manifold for XY3 (D 3h ) molecules corresponding to a set of seven VICs. As an application, the quartic canonical force field in curvilinear redundant internal coordinates of BH3 is determined from ab initio force fields in normal coordinates calculated at the coupled-cluster singles and doubles level with perturbative treatment of the triples in conjunction with a triple- and quadruple-? size basis set. This anharmonic force field so obtained for the borane molecule, and in general for XY3 (D 3h ) molecules, is uniquely defined (therefore in an unambiguous form) and depending on the same number of parameters, i.e., force constants, when independent coordinates (natural or symmetry) are used in its description. PMID:24842323

Ródenas, Consuelo Rosales; Quesada, Juana Vázquez; Torres, Emilio Martínez; González, Juan Jesús López

2014-06-01

89

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

PubMed Central

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 Å for 4 residues loops, 0.84/0.46 Å for 8 residue loops, and 1.16/0.73 Å for 12 residue loops. To our knowledge, these results are significantly better than or comparable to those reported to date for any loop modeling method that does not take crystal packing into account. Moreover, the accuracy of our method is on par with the best previously reported results obtained considering the crystal environment. We attribute this success to the high accuracy of the new ICM force field achieved by meticulous parameterization, to the optimized solvent model, and the efficiency of the search method.

Arnautova, Yelena A.; Abagyan, Ruben A.

2010-01-01

90

High sensitivity detection of protein molecules picked up on a probe of atomic force microscope based on the fluorescence detection by a total internal reflection fluorescence microscope  

Microsoft Academic Search

We developed a method to detect and identify proteins on a probe of the atomic force microscope (AFM) with a high sensitivity. Due to a low background noise of the total internal reflection fluorescence microscope employed as a detecting system, we were able to achieve a high enough sensitivity to detect zeptomole orders of protein molecules immobilized on the tip.

Takafumi Yamada; Rehana Afrin; Hideo Arakawa; Atsushi Ikai

2004-01-01

91

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

PubMed Central

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.

Gueron, S; Levit-Gurevich, K

1998-01-01

92

The relative contributions of radiative forcing and internal climate variability to the late 20th Century winter drying of the Mediterranean region  

NASA Astrophysics Data System (ADS)

The roles of anthropogenic climate change and internal climate variability in causing the Mediterranean region's late 20th Century extended winter drying trend are examined using 19 coupled models from the Intergovernmental Panel on Climate Change Fourth Assessment Report. The observed drying was influenced by the robust positive trend in the North Atlantic Oscillation (NAO) from the 1960s to the 1990s. Model simulations and observations are used to assess the probable relative roles of radiative forcing, and internal variability in explaining the circulation trend that drove much of the precipitation change. Using the multi-model ensemble we assess how well the models can produce multidecadal trends of realistic magnitude, and apply signal-to-noise maximizing EOF analysis to obtain a best estimate of the models' (mean) sea-level pressure (SLP) and precipitation responses to changes in radiative forcing. The observed SLP and Mediterranean precipitation fields are regressed onto the timeseries associated with the models' externally forced pattern and the implied linear trends in both fields between 1960 and 1999 are calculated. It is concluded that the radiatively forced trends are a small fraction of the total observed trends. Instead it is argued that the robust trends in the observed NAO and Mediterranean rainfall during this period were largely due to multidecadal internal variability with a small contribution from the external forcing. Differences between the observed and NAO-associated precipitation trends are consistent with those expected as a response to radiative forcing. The radiatively forced trends in circulation and precipitation are expected to strengthen in the current century and this study highlights the importance of their contribution to future precipitation changes in the region.

Kelley, Colin; Ting, Mingfang; Seager, Richard; Kushnir, Yochanan

2012-05-01

93

The relative contributions of radiative forcing and internal climate variability to the late 20th Century winter drying of the Mediterranean region  

NASA Astrophysics Data System (ADS)

The roles of anthropogenic climate change and internal climate variability in causing the Mediterranean region's late 20th Century extended winter drying trend are examined using 19 coupled models from the Intergovernmental Panel on Climate Change Fourth Assessment Report. The observed drying was influenced by the robust positive trend in the North Atlantic Oscillation from the 1960s to the '90s. Model simulations and observations are used to assess the probable relative roles of radiative forcing, and internal variability in explaining the circulation trend that drove much of the precipitation change. Using the multi-model ensemble we assess how well the models can produce multidecadal trends of realistic magnitude, and apply signal-to-noise maximizing EOF analysis to obtain a best estimate of the models' (mean) sea-level pressure (SLP) and precipitation responses to changes in radiative forcing. The observed SLP and Mediterranean precipitation fields are regressed onto the timeseries associated with the models' externally forced pattern and the implied linear trends in both fields between 1960 and 1999 are calculated. It is concluded that the radiatively forced trends are a small fraction of the total observed trends. Instead it is argued that the robust trends in the observed NAO and Mediterranean rainfall during this period were largely due to multidecadal internal variability with a small contribution from the external forcing. Differences between the observed and NAO-associated precipitation trends are consistent with those expected as a response to radiative forcing. The radiatively forced trends in circulation and precipitation are expected to strengthen in the current century and this study highlights the importance of their contribution to future precipitation changes in the region.

Kelley, C. P.; Ting, M.; Seager, R.; Kushnir, Y.

2011-12-01

94

Subthalamic nucleus and internal globus pallidus scale with the rate of change of force production in humans  

Microsoft Academic Search

The basal ganglia, motor cortex, and cerebellum have been implicated as a circuit that codes for movement velocity. Since movement velocity covaries with the magnitude of force exerted and previous studies have shown that similar regions scale in activation for velocity and force, the scaling of neuronal activity with movement velocity could be due to the force exerted. The present

David E. Vaillancourt; Mary A. Mayka; Keith R. Thulborn; Daniel M. Corcos

2004-01-01

95

Use of United States Military Force in the Post Cold War Era. NASA: International Training and Integration Office Improving Interaction and Cooperation With the International Partners.  

National Technical Information Service (NTIS)

As the trend towards globalization continues, international cooperation in space has become increasingly prevalent. Globalization has presented a new age of growth and shared prosperity through a more efficient allocation of resources making international...

K. N. Reed

2000-01-01

96

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)

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.

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

2013-12-01

97

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

NASA Astrophysics Data System (ADS)

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.

Tomitori, Masahiko; Onishi, Hiroshi

2007-02-01

98

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

NASA Astrophysics Data System (ADS)

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.

Reichling, M.; Mikosch, W.

2006-04-01

99

Numerical analysis of the flow and heat transfer characteristics for forced convection-radiation in entrance region of an internally finned tubes  

Microsoft Academic Search

The flow and heat transfer characteristics of combined forced convection and radiation in the entrance region of internally\\u000a finned tubes are investigated numerically in this paper. The uniform flow is considered for an inlet flow condition. A three\\u000a dimensional parabolic problem is solved by a marching-type procedure envolving a series of two dimensional elliptic problems\\u000a in the cross-stream plane. The

Hi-Yong Pak; Kyoung-Woo Park; Moon-Suk Choi

1998-01-01

100

THE IMPACT OF SAGITTAL PLANE HIP POSITION ON ISOMETRIC FORCE OF HIP EXTERNAL ROTATOR AND INTERNAL ROTATOR MUSCLES IN HEALTHY YOUNG ADULTS  

PubMed Central

Purpose/Background: Hip external rotator (ER) and internal rotator (IR) muscle weakness is theorized to be associated with lower extremity injury in athletes including knee ligament tears and patellofemoral pain. Previous studies investigating hip musculature strength have utilized various sagittal plane hip positions for testing. The relationship between results at these different positions is unknown. Methods: Eighty healthy, pain?free young adults participated in the study: 40 female, mean age 22.90 (± 2.32) years, and 40 male, mean age 23.50 (± 2.15) years. Peak isometric torque of bilateral hip ER and IR were tested at 90° and 0° of hip flexion with an instrumented dynamometer. Peak muscle forces were calculated. Peak forces were normalized by body mass. Mean normalized force was calculated for dominant and non?dominant limbs for ER and IR in both positions. Male and female data were analyzed separately with paired t?tests (2?tailed). Reference values for average muscle force and torque were calculated for dominant and non?dominant limbs for both hip positions. Results: Hip IR normalized peak force was greater at 90° compared to 0° flexion position bilaterally in both genders (p < .01). Hip ER normalized peak force was greater at 90° compared to 0° flexion in dominant limbs of both genders and in non?dominant limbs of males (p < .01). Non?dominant hip ER normalized force in females was greater at 90° versus 0° flexion; however, it was not significant (p = .092). Post hoc analysis of normalized average force (average over 5?second contraction) yielded similar results. Conclusion: Clinicians and researchers should use consistent positioning for testing of hip ER and IR strength. This will improve certainty of determining if a patient’s strength has changed or if differences between groups are present. Reference values reported will be useful in order to determine if weakness is present and to set goals, particularly in cases of bilateral involvement. Level of Evidence: 2b

Wong, Anson L. K.; Rickards, Cory

2014-01-01

101

Liquid sloshing in cargo tanks. Liquid slosh loading in slack ship tanks: Forces on internal structure and pressures  

NASA Astrophysics Data System (ADS)

Based on a survey of 12 cases of sloshing damage on 7 tankers and other ships of dry cargo, ore-bulk-oil, bulk, and ore carrier types, 5 structural members were chosen for model testing to measure sloshing forces. Oscillating table tests were then run using partially filled tanks with realistic structure including the instrumented members. Sloshing forces and moment coefficients are reported as well as sloshing pressure coefficients from pressure measurements on the tanks. A linear superposition calculation for sloshing force on one member is shown.

Hamlin, N. A.

102

Beyond the Tenth Year in Afghanistan: Security Force Assistance and International Security (E-Notes, September 2011).  

National Technical Information Service (NTIS)

While Taliban totalitarianism attempted to destroy Afghans' future, the international community has attempted to reverse societal regression. To be sure, Afghanistan still has many challenges, but it is also not the fragmented society it once was either. ...

D. S. Reveron I. W. Caldwell

2011-01-01

103

Fabrication of internal driven micro centrifugal force pump based on synchronous micro motors with polymer magnet rotors  

Microsoft Academic Search

In this paper the fabrication of a micro centrifugal force pump based on a synchronous motor is presented. The pump unit as well as the electromagnetic drive unit is fully integrated and mainly realized by means of micro fabrication technologies including UV-depth lithography and electroplating. Furthermore, one specialty is the application of polymer magnets which allow a miniaturization of the

Andreas Waldschik; Stephanus Büttgenbach

2009-01-01

104

High sensitivity detection of protein molecules picked up on a probe of atomic force microscope based on the fluorescence detection by a total internal reflection fluorescence microscope.  

PubMed

We developed a method to detect and identify proteins on a probe of the atomic force microscope (AFM) with a high sensitivity. Due to a low background noise of the total internal reflection fluorescence microscope employed as a detecting system, we were able to achieve a high enough sensitivity to detect zeptomole orders of protein molecules immobilized on the tip. Several different methods to immobilize protein molecules to AFM-probes were tested, meant for a wide range of applications of this method. Furthermore, we demonstrated that different proteins were clearly distinguished by immunofluorescence microscopy on the probe using their specific antibodies. PMID:15225609

Yamada, Takafumi; Afrin, Rehana; Arakawa, Hideo; Ikai, Atsushi

2004-07-01

105

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

Microsoft Academic Search

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

Masahiko Tomitori; Hiroshi Onishi

2007-01-01

106

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

Microsoft Academic Search

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

2007-01-01

107

Modulation of internal model formation during force field-induced motor learning by anodal transcranial direct current stimulation of primary motor cortex  

PubMed Central

Human subjects can quickly adapt and maintain performance of arm reaching when experiencing novel physical environments such as robot-induced velocity-dependent force fields. Using anodal transcranial direct current stimulation (tDCS) this study showed that the primary motor cortex may play a role in motor adaptation of this sort. Subjects performed arm reaching movement trials in three phases: in a null force field (baseline), in a velocity-dependent force field (adaptation; 25 N s m?1) and once again in a null force field (de-adaptation). Active or sham tDCS was directed to the motor cortex representation of biceps brachii muscle during the adaptation phase of the motor learning protocol. During the adaptation phase, the global error in arm reaching (summed error from an ideal trajectory) was similar in both tDCS conditions. However, active tDCS induced a significantly greater global reaching (overshoot) error during the early stage of de-adaptation compared to the sham tDCS condition. The overshoot error may be representative of the development of a greater predictive movement to overcome the expected imposed force. An estimate of the predictive, initial movement trajectory (signed error in the first 150 ms of movement) was significantly augmented during the adaptation phase with active tDCS compared to sham tDCS. Furthermore, this increase was linearly related to the change of the overshoot summed error in the de-adaptation process. Together the results suggest that anodal tDCS augments the development of an internal model of the novel adapted movement and suggests that the primary motor cortex is involved in adaptation of reaching movements of healthy human subjects.

Hunter, Timothy; Sacco, Paul; Nitsche, Michael A; Turner, Duncan L

2009-01-01

108

The stability of ribbed cylindrical shells in combined loading by an axial force, a torsional moment, and internal pressure  

Microsoft Academic Search

The results of an experimental investigation of the stability of cylindrical shells (r=200 mm, l=384 mm, h=0.5 mm) of titanium alloy regularly reinforced by 36 stringers and 2 ribs and freely supported on the edges are given. The parameter of internal pressure ¯q=q\\/E·(r\\/h)2 varies from 0 to 0.85 so that at its maximum values failure of the shells occurred as

A. S. Pal'chevskii; A. I. Kukarina

1993-01-01

109

The stability of ribbed cylindrical shells in combined loading by an axial force, a torsional moment, and internal pressure  

Microsoft Academic Search

The results of an experimental investigation of the stability of cylindrical shells (r = 200 mm, l = 384 mm, h = 0.5 mm) of titanium alloy regularly reinforced by 36 stringers and 2 ribs and freely supported on the edges are given. The parameter of internal pressure {bar q} = q\\/E·(r\\/h)² varies from 0 to 0.85 so that at

A. I. Kukarina

1994-01-01

110

Influence of forced internal air circulation on airflow distribution and heat transfer in a gas double-dynamic solid-state fermentation bioreactor.  

PubMed

Internal air circulation affects the temperature field distribution in a gas double-dynamic solid-state fermentation bioreactor (GDSFB). To enhance heat transfer through strengthening internal air circulation in a GDSFB, we put an air distribution plate (ADP) into the bioreactor and studied the effects of forced internal air circulation on airflow, heat transfer, and cellulase activity of Trichoderma viride L3. Results showed that ADP could help form a steady and uniform airflow distribution, and with gas-guide tubes, air reversal was formed inside the bioreactor, thus resulting in a smaller temperature difference between medium and air by enhancing convective heat transfer inside the bioreactor. Using an ADP of 5.35 % aperture ratio caused a 1 °C decrease in the average temperature difference during the solid-state fermentation process of T. viride L3. Meanwhile, the cellulase activity of T. viride L3 increased by 13.5 %. The best heat-transfer effect was attained when using an ADP of 5.35 % aperture ratio and setting the fan power to 125 V (4.81 W) in the gas double-dynamic solid-state fermentation (GDSF) process. An option of suitable aperture ratio and fan power may be conducive to ADPs' industrial amplification. PMID:24347160

Chen, Hongzhang; Qin, Lanzhi; Li, Hongqiang

2014-02-01

111

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

NASA Technical Reports Server (NTRS)

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.

Charlock, T. P.; Ramanathan, V.

1985-01-01

112

The stability of ribbed cylindrical shells in combined loading by an axial force, a torsional moment, and internal pressure  

SciTech Connect

The results of an experimental investigation of the stability of cylindrical shells (r = 200 mm, l = 384 mm, h = 0.5 mm) of titanium alloy regularly reinforced by 36 stringers and 2 ribs and freely supported on the edges are given. The parameter of internal pressure {bar q} = q/E{center_dot}(r/h){sup 2} varies from 0 to 0.85 so that at its maximum values failure of the shells occurred as the result of exhaustion of the strength of the material. It is shown that within the limits of elasticity the experimental values of the critical loads agree well with the calculated obtained according to an approximate method using a monomial approximation of deflection and introducing the empirical coefficient 1/2 to the value of internal pressure. Depending upon the combination of individual constituents of combined loading there are two forms of loss of rigidity, bulging of the shell between the ribs or combined bulging of the shell and the stringers between the ribs.

Pal`chevskii, A.S.; Kukarina, A.I. [Institute of Mechanics, Kiev (Ukraine)

1994-08-01

113

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

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

114

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)

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.

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

2006-01-01

115

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

PubMed

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

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

2013-07-01

116

Diabetes mellitus in older people: position statement on behalf of the International Association of Gerontology and Geriatrics (IAGG), the European Diabetes Working Party for Older People (EDWPOP), and the International Task Force of Experts in Diabetes.  

PubMed

Diabetes mellitus is a highly prevalent metabolic condition in ageing societies associated with high levels of morbidity, multiple therapies, and functional deterioration that challenges even the best of health care systems to deliver high-quality, individualized care. Most international clinical guidelines have ignored the often-unique issues of frailty, functional limitation, changes in mental health, and increasing dependency that characterize many aged patients with diabetes. A collaborative Expert Group of the IAGG and EDWPOP and an International Task Force have explored the key issues that affect diabetes in older people using a robust method comprising a Delphi process and an evidence-based review of the literature. Eight domains of interest were initially agreed and discussed: hypoglycemia, therapy, care home diabetes, influence of comorbidities, glucose targets, family/carer perspectives, diabetes education, and patient safety. A set of "consensus" statements was produced in each domain of interest. These form a foundation for future policy development in this area and should influence the clinical behavior and approach of all health professionals engaged in delivering diabetes care to older people. PMID:22748719

Sinclair, Alan; Morley, John E; Rodriguez-Mañas, Leo; Paolisso, Giuseppe; Bayer, Tony; Zeyfang, Andrej; Bourdel-Marchasson, Isabelle; Vischer, Ulrich; Woo, Jean; Chapman, Ian; Dunning, Trisha; Meneilly, Graydon; Rodriguez-Saldana, Joel; Gutierrez Robledo, Luis Miguel; Cukierman-Yaffe, Tali; Gadsby, Roger; Schernthaner, Guntram; Lorig, Kate

2012-07-01

117

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)

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.

Schmitt, Rafael; Bizzi, Simone; Castelletti, Andrea

2013-04-01

118

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

PubMed

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

Barbier, Charlotte; Humphrey, Joseph A C

2009-07-01

119

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

PubMed Central

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.

Barbier, Charlotte; Humphrey, Joseph A.C.

2008-01-01

120

A Comparison between International Obesity Task Force and Center for Disease Control References in Assessment of Overweight and Obesity Among Adolescents in Babol, Northern Iran  

PubMed Central

Objective: This study compares the Center for Disease Control (CDC) and International Obesity Task Force (IOTF) references in assessment of overweight and obesity among Iranian adolescents. Methods: The data of this study was drawn from a cross sectional study of a representative sample of 1200 adolescents aged 12-17 years in Babol, northern Iran. A standard procedure was used to measure height and weight and the body mass index was calculated. Each subject was classified as overweight and obese based on IOTF cut off values of BMI and CDC references BMI percentile sets by age and sex. The kappa coefficients were estimated for the degree of agreement. Results: In assessment of obesity/overweight prevalence, the CDC and IOTF references produced a similar estimate by age group and sex. The maximum differences was about 1% and the kappa coefficients was 0.96 to 1 (P = 0.001). While for assessment of obesity, the CDC reference produced slightly a higher rate of obesity and the difference in prevalence between the two sets of references was ranged from 1.4% to 3.2% with kappa coefficients: 0.90 to 0.70 (P = 0.001) depending on the age group and sex and a greater difference was observed among younger age group. Conclusion: The findings suggest an excellent agreement between the TOTF and CDC references in assessment of overall overweight/obesity prevalence among adolescent boys and girls. While in assessment of obesity prevalence alone the degree of agreement between the two sets of references slightly diminished. Overall, the two references are comparable and the agreement varies a little with respect to age and sex.

Hajian-Tilaki, Karimollah; Heidari, Behzad

2013-01-01

121

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)

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.

Kim, Yongseung

1994-01-01

122

Force Display and Bi-Lateral Master-Slave Control with an Internal Model under the Consideration of Human Cross-Over Model  

NASA Astrophysics Data System (ADS)

Human behavior for controlling machines is quite adaptive but restrictive in gain, phase, frequency bandwidth and so on. It is often assumed by a cross-over model especially for compensatory tracking task. Force display system is increasingly important in robotics, remote manipulations, machine handling and etc. The control system design for force display and/or bi-lateral master-slave manipulator is not so easy because of gain limits, mechanical vibration, human-induced oscillation and others. Proposed is a control system design for force display and/or bi-lateral master-slave manipulator based on model-following control under the concept of human crossover model in compensatory tracking. Experimental results are also shown for an actual force display device designed by the proposed method.

Kawahata, Nagakatsu; Nishizawa, Masanori; Itoh, Youichirou; Yoshida, Hiroaki

123

Near-field photonic forces  

Microsoft Academic Search

A review of recent advancements in photonic forces is presented. We discuss in detail the interaction of light and sub-wavelength particles on a substrate illuminated by total internal reflection, and we study the optical forces experienced by the particles. The effects of plasmon-mode excitations on the resulting photonic forces on metallic particles are also addressed. Moreover, we explore the possibility

P. C. C haumet

2004-01-01

124

Experimental investigation on forced convective heat transfer and pressure drop of ethylene glycol in tubes with three-dimensional internally extended surface  

Microsoft Academic Search

A new type of tube is introduced that has a three-dimensional internally extended surface used to enhance convective heat transfer inside the tube. Results are presented from experimental investigations into heat transfer performance in seven copper tubes of about 13.5 mm I.D. with three-dimensional internally extended surfaces (3-DIESTs) varying in axial pitch, circumferential pitch, height, width, and fin arrangement. The

Q. Liao; M. D. Xin

1995-01-01

125

Russian nuclear forces, 2012  

Microsoft Academic Search

Despite the promise of a more transparent future after Russia's ratification of New START in January 2011, the international community’s ability to monitor developments in Russia’s nuclear forces has become more difficult because the Kremlin does not release full aggregate treaty numbers of the country’s strategic nuclear forces and the United States has agreed not to make the information available

Hans M. Kristensen; Robert S. Norris

2012-01-01

126

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)

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. .

Snedeker, Jess G.; Cavanagh, Peter R.

2000-01-01

127

Good Research Practices for Measuring Drug Costs in Cost-Effectiveness Analyses:An International Perspective: The ISPOR Drug CostTask Force Report—PartVI  

Microsoft Academic Search

Objective: The pharmacoeconomic guidelines available in the literature or promulgated in many countries are either vague or silent about how drug costs should be established or measured so an international comparison of cost-effectiveness analysis (CEA) results can be made. The objective of this report is to provide guidance and recommendations on how drug costs should be measured for CEAs done

Lizheng Shi; Meredith Hodges; Michael Drummond; Jeonghoon Ahn; Shu Chuen Li; Shanlian Hu; Federico Augustovski; Joel W. Hay; Jim Smeeding

128

Nuclear forces  

SciTech Connect

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

Machleidt, R. [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States)

2013-06-10

129

HRP ForceShoe Evaluation  

NASA Video Gallery

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

130

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

131

World politics and international economics  

Microsoft Academic Search

International economists and political scientists analyze the influence of political and economic forces on the world in an effort to explain why the old international economic order has collapsed and what can and should be done about it. The impact of these forces is examined for each of the functional components of the world economy: international monetary system, world trade,

C. F. Bergsten; L. B. Krause

1975-01-01

132

Dextrous hand grasping force optimization  

Microsoft Academic Search

A key goal in dextrous robotic hand grasping is to balance external forces and at the same time achieve grasp stability and minimum grasping energy by choosing an appropriate set of internal grasping forces. Since it appears that there is no direct algebraic optimization approach, a recursive optimization, which is adaptive for application in a dynamic environment, is required. One

Martin BUSS; Hideki Hashimoto; John B. Moore

1996-01-01

133

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

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

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

2013-11-01

134

Dam Forces  

NSDL National Science Digital Library

Students learn how the force of water helps determine the size and shape of dams. They use clay to build models of four types of dams, and observe the force of the water against each type. They conclude by deciding which type of dam they, as Splash Engineering engineers, will design for Thirsty County.

Integrated Teaching And Learning Program And Laboratory

135

Mobile Forces  

NSDL National Science Digital Library

The application of engineering principles is explored in the creation of mobiles. As students create their own mobiles, they take into consideration the forces of gravity and convection air currents. They learn how an understanding of balancing forces is important in both art and engineering design.

Integrated Teaching And Learning Program

136

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

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

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

137

Air Force Seal Programs  

NASA Technical Reports Server (NTRS)

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

Mayhew, Ellen R.

1996-01-01

138

Forces Lab  

NSDL National Science Digital Library

In this interactive activity from the Building Big Web site, select one of the actions of squeezing, stretching, bending, sliding, or twisting to explore the forces of compression, tension, shear, and torsion.

Foundation, Wgbh E.

2004-01-22

139

Centripetal Force  

NSDL National Science Digital Library

In this animation a ball bounces off the sides of the circle, and the number of sides double, until the circle appears to exert force on a ball that is constant in size and always directed towards the center.

Wpsu

2010-04-09

140

Physlet Force Concept Inventory: Forces  

NSDL National Science Digital Library

A large truck breaks down out on the road and receives a push back into town by a small compact car as shown in the animation. Learners are to answer questions regarding forces exerted by the two vehicles.

Christian, Wolfgang; Belloni, Mario

2006-01-13

141

Forces Lab  

NSDL National Science Digital Library

This set of interactive online simulations shows the forces that may be at work on geologic structures or on man-made structures during an earthquake. Users can see examples of compression, tension, bending, and torsion. Each simulation also features a link to a photo of a real-life example.

2011-11-01

142

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

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.

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

143

Forced Migration Online  

NSDL National Science Digital Library

Designed to function as a comprehensive website that provides access to various resources on forced human migration, this site is provided through the courtesy of the staff at the Refugee Studies Centre at the University of Oxford. While the users of this site will encounter a seamlessly integrated resource, the site contains four separate components. These elements include a searchable digital library, a searchable catalogue with descriptions of and links to Internet-based resources, and a series of geographic and thematic research guides. The homepage offers users access to all of these resources, along with a sidebar that features relevant upcoming events as the International Day of Older Persons. The site also affords visitors access to the full-text of three important publications in the field: Disasters, Forced Migration Review, and International Migration Review (some archived journals are several years behind the current issue). It is worth noting that the homepage also contains a link to a nice introductory essay by Sean Loughna titled "What is Forced Migration?"

144

Friction Force  

NSDL National Science Digital Library

Students use LEGO® MINDSTORMS® robotics to help conceptualize and understand the force of friction. Specifically, they observe how different surfaces in contact result in different frictional forces. A LEGO robot is constructed to pull a two-wheeled trailer made of LEGO parts. The robot is programmed to pull the trailer 10 feet and trial runs are conducted on smooth and textured surfaces. The speed and motor power of the robot is kept constant in all trials so students observe the effect of friction between various combinations of surfaces and trailer wheels. To apply what they learn, students act as engineers and create the most effective car by designing the most optimal tires for given surface conditions.

Applying Mechatronics to Promote Science (AMPS) Program GK-12,

145

Forced Migration Review  

NSDL National Science Digital Library

Published tri-annually since January 1998, the Forced Migration Review (FMR) is the in-house journal of the Refugee Studies Centre at the University of Oxford. The journal (and its online edition made available on this site) is published in English, Arabic, and Spanish, and "provides the humanitarian community with a practice-oriented forum for debate on issues facing refugees and internally displaced people in order to improve policy and practice." From the site, visitors can browse through single articles or complete issues of the journal all the way back to 1998. Many of the issues are dedicated to a single theme, including recent issues which have been titled When does internal displacement end? and Reproductive health for displaced people: Investing in the future. The site also provides ample information on submitting articles to the journal, material on the current editorial board, and the themes for upcoming issues. Rounding out the site is a collection of related links for consideration, organized into topics such as international law, reproductive health and forced migration research institutes and centers.

146

Air Force seal activities  

NASA Technical Reports Server (NTRS)

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

Mayhew, Ellen R.

1994-01-01

147

Estimation of Coriolis Force and Torque Acting on Ares-1  

NASA Technical Reports Server (NTRS)

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).

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

2011-01-01

148

Air Force UAVs: The Secret History.  

National Technical Information Service (NTIS)

This paper explores Air Force UAV systems using a comparative analytical framework. Systems are presented chronologically and the analysis focuses on external and internal variables contributing to weapon system innovation. As with the other services, ind...

T. P. Ehrhard

2010-01-01

149

Tip models and force definitions in molecular dynamics simulations of scanning force microscopy  

NASA Astrophysics Data System (ADS)

The definition of the time varying force on a tip with internal degrees of freedom in atomistic molecular dynamics (MD) simulations of scanning force microscopy experiments is discussed. We show that the static expression for the tip force is inadequate for calculating force fluctuations within the MD simulations and suggest a different method of calculating the tip force. By studying the size of tip force fluctuations for different tip models and various tip positions with respect to the surface, we demonstrate that the new method works equally well in both static and dynamic cases.

Trevethan, T.; Kantorovich, L.

2003-08-01

150

Internal-tide generation and destruction by shoaling internal tides  

Microsoft Academic Search

Internal-tide generation is usually predicted from local topography, surface tides, and stratification. However, internal tides are often observed to be unrelated to local spring-neap forcing, appearing intermittently in 3–5 day bursts. Here we suggest a source of this intermittency by illustrating how remotely-generated shoaling internal tides induce first-order changes in local internal-tide generation. Theory, numerical simulations, and observations show that

S. M. Kelly; J. D. Nash

2010-01-01

151

Forces for electromechanical integrated electrostatic harmonic drive  

Microsoft Academic Search

In this paper, electromechanical coupled force between flexible ring and stator for the drive is given and defined in Fourier series form. Using displacement function, basic equations of the internal forces and displacements are presented. The displacement function is defined in Fourier series form and three equivalent differential equations are obtained. From the three differential equations, above displacement function and

Lizhong Xu; Lei Qin; Cuirong Zhu

2007-01-01

152

Knee joint forces: prediction, measurement, and significance.  

PubMed

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

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

2012-02-01

153

Internal auditing education : a comparison across countries  

Microsoft Academic Search

Society?s recognition of the importance of internal auditing has increased in recent years. This has resulted in an increased recognition of the need for improving and formalizing the manner in which internal auditors are educated. Suggests some of the forces that have led to this increased awareness of the value of internal auditing and discusses historical changes in internal auditing

Sheila D. Foster; Mary Brady Greenawalt

1995-01-01

154

Foreign Internal Defense.  

National Technical Information Service (NTIS)

Foreign Internal Defense (FID) is one of the primary ways that the Air Force conducts Building Partnerships -- a Service Core Function. FID is defined in JP 3-22 as the participation by civilian and military agencies of a government in any of the action p...

2010-01-01

155

Variable Direction Force Coupler.  

National Technical Information Service (NTIS)

A variable direction force coupler is described for transmitting a reciprocating force along a selectable curved path. The coupler consists of a flexible tube filled with rigid balls, including force transmission members at each end which are adapted to c...

W. H. Hespenhide

1970-01-01

156

Capillary force in atomic force microscopy  

NASA Astrophysics Data System (ADS)

Under ambient conditions, a water meniscus generally forms between a nanoscale atomic force microscope tip and a hydrophilic surface. Using a lattice gas model for water and thermodynamic integration methods, we calculate the capillary force due to the water meniscus for both hydrophobic and hydrophilic tips at various humidities. As humidity rises, the pull-off force rapidly reaches a plateau value for a hydrophobic tip but monotonically increases for a weakly hydrophilic tip. For a strongly hydrophilic tip, the force increases at low humidities (<30%) and then decreases. We show that mean-field density functional theory reproduces the simulated pull-off force very well.

Jang, Joonkyung; Schatz, George C.; Ratner, Mark A.

2004-01-01

157

Manipulating and grasping forces in manipulation by multifingered robot hands  

Microsoft Academic Search

A new definition of grasping and manipulating forces for multifingered robot hands is proposed. First, a short discussion of the grasping and manipulating forces for two-fingered hands with linear motion is given to explain the motivation more clearly and to give the basic idea of the new definition. Then, for three-fingered hands, based on a representation of the internal force,

Tsuneo Yoshikawa; Kiyoshi Nagai

1991-01-01

158

Internal Bleeding  

MedlinePLUS

... Caregivers > Injuries and Poisoning > First Aid 4 Internal Bleeding Heavy internal bleeding may occur in the abdominal cavity, chest cavity, ... femur) and pelvis, that are broken. Initially, internal bleeding may cause no symptoms, although an injured organ ...

159

Air Force brush seal programs  

NASA Technical Reports Server (NTRS)

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.

Dowler, Connie

1993-01-01

160

Force regulation in multiple-manipulator systems  

NASA Technical Reports Server (NTRS)

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.

Wen, John T.; Murphy, Steve H.

1992-01-01

161

Cell Adhesion Force Microscopy  

Microsoft Academic Search

The adhesion forces of cervical carcinoma cells in tissue culture were measured by using the manipulation force microscope, a novel atomic force microscope. The forces were studied as a function of time and temperature for cells cultured on hydrophilic and hydrophobic polystyrene substrates with preadsorbed proteins. The cells attached faster and stronger at 37 degrees C than at 23 degrees

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

1999-01-01

162

Efficacy of climate forcings  

Microsoft Academic Search

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

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

2005-01-01

163

Efficacy of climate forcings  

Microsoft Academic Search

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

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

2005-01-01

164

Protein folding forces.  

PubMed

We investigate the average inter-residue folding forces derived from mutational data of the 15 proteins: barstar, barnase, chymotrypsin inhibitor 2 (CI2), Src SH3 domain, spectrin R16 domain, Arc repressor, apo-azurin, cold shock protein B (cspB), C-terminal domain of ribosomal protein L9 (CTL9), FKBP12, alpha-lactalbumin, colicin E7 immunity protein 7 (IM7), colicin E9 immunity protein 9 (IM9), spectrin R17 domain, and ubiquitin. The residue-specific contributions to folding in most of the 15 protein molecules are highly non-uniformly distributed and are typically about 1piconewton (pN) per interaction. The strongest folding forces often occur in some of the helices and strands of folding nuclei which suggests that folding nucleation-condensation is partially directed by formation of some secondary structure interactions. The correlation of the energy changes of mutants with inter-residue contact maps of the protein molecules provides a higher resolution than assigning the mutant data to certain positions in the polypeptide strand alone. In contrast to previous Phi-value analysis, we now can partially resolve folding motions. Compaction of at least one alpha-helix along its axis mediated by internal hydrogen bonds and stabilized by diffuse tertiary structure interactions appears to be one important molecular event during early folding in barstar, CI2, spectrin R16 domain, Arc repressor, alpha-lactalbumin, IM7, IM9, and spectrin R17 domain. A lateral movement of at least two strands neighbored in sequence towards each other appears to be involved in early folding of the SH3 domain, cspB, CTL9, and FKBP12. PMID:18177671

Nölting, Bengt; Salimi, Neema; Guth, Ulrich

2008-03-21

165

Knudsen forces on microcantilevers  

NASA Astrophysics Data System (ADS)

When two surfaces at two different temperatures are separated by a distance comparable to a mean-free path of the molecules of the ambient medium, the surfaces experience Knudsen force. This mechanical force can be important in microelectromechanical systems and in atomic force microscopy. A theoretical discussion of the magnitude of the forces and the conditions where they can be encountered is discussed. A potential application of the Knudsen force in designing a cantilever-based vacuum gauge is discussed.

Passian, A.; Wig, A.; Meriaudeau, F.; Ferrell, T. L.; Thundat, T.

2002-11-01

166

Physicists' Forced Migrations under Hitler  

NASA Astrophysics Data System (ADS)

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.

Beyerchen, Alan

2011-03-01

167

Dietary Supplements Task Force.  

National Technical Information Service (NTIS)

The Dietary Supplements Task Force was charged with examining the issues regarding dietary supplements and developing a regulatory framework for these products. To facilitate the orderly development of regulatory strategies, the Task Force divided the uni...

1992-01-01

168

Methamphetamine Interagency Task Force.  

National Technical Information Service (NTIS)

The Methamphetamine Interagency Task Force was established in 1996 in response to a provision of the Comprehensive Methamphetamine Control Act. This report represents the 2-year effort of the Task Force presenting: the principles that have guided the Task...

2000-01-01

169

Broken Wave Forces.  

National Technical Information Service (NTIS)

To provide revised guidance on broken wave forces. A determination of broken wave forces on structures is necessary for structure design, and also for determining economic benefits of hurricane protection projects. The Shore Protection Manual (SPM 1984), ...

1991-01-01

170

Forces and Motion: Basics  

NSDL National Science Digital Library

Explore the forces at work in a tug of war or pushing a refrigerator, crate, or person. Create an applied force and see how it makes objects move. Change friction and see how it affects the motion of objects.

Simulations, Phet I.; Podolefsky, Noah; Reid, Sam; Paul, Ariel; Perkins, Kathy; Loeblein, Trish

2012-10-24

171

Force-controlled microgripping  

NASA Astrophysics Data System (ADS)

When grasping microparts extremely low gripping low forces, often in the micro to nano newton range, must be applied in order to prevent parts from being damaged and to prevent them from dislodging in the gripper. This paper presents our work in developing a force controlled microgripper and microgripping strategies using optical beam deflection techniques. The optical beam deflection sensor is based on modified Atomic Force Microscope techniques and is able to resolve forces below a nanonewton. A variety of gripper fingers made from materials with different conductivity and surface roughness are analyzed theoretically and experimentally using the force sensor. These results provide insight into the mechanics of micromanipulation, and the results are used to develop microgripping strategies. A design of a microfabricated force controlled microgripper is presented along with initial experimental results in applying various gripping forces to microparts. The results demonstrate the important role gripping force plays in the grasping and release of microparts.

Zhou, Yu; Nelson, Bradley J.

1999-08-01

172

Force and Motion  

NSDL National Science Digital Library

Explore interactive sites and sites with information about putting objects into motion with different forces. 1. Read the top two sections about Motion and Force and then answer questions #1 and #2 on your worksheet. Force and Motion Information 2. Scroll down and read the section about inertia. Force and Motion Information Then click the box that says "law of inertia" and learn more about inertia on this page. Newton s Laws Now answer #3 ...

Benson, Carrie

2013-01-31

173

Solvation force simulations in atomic force microscopy.  

PubMed

Solvation force oscillation in octamethylcyclotetrasiloxane (OMCTS) versus the distance between an atomic force microscope (AFM) tip and mica substrate has been studied through molecular dynamics simulations. A driving spring model in a liquid-vapor molecular ensemble is used to explore the force oscillation mechanism. It has been found that OMCTS fluid in tip-substrate contact has a strong tendency to form a layered structure, starting from n = 8 layers. The force profile obtained from simulation is qualitatively similar to those in contact mode AFM experiments. However, the bulk-like diffusion and rotation of OMCTS molecules underneath the AFM tip suggest that, under the tip-substrate confinement geometry, the layered OMCTS film cannot form a solidified structure except under n = 2 extreme contact-layer confinement. PMID:24908030

Xu, Rong-Guang; Leng, Yongsheng

2014-06-01

174

Crossflow force transducer. [LMFBR  

SciTech Connect

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.

Mulcahy, T.M.

1982-05-01

175

Forces: Pushing and Pulling  

NSDL National Science Digital Library

This lesson demonstrates how students can use cause and effect to describe how objects move using a push or pull (forces). The students will understand that forces put objects in motion and that a strong force could change the direction and speed of an object.

2012-10-12

176

Tactical force protection  

Microsoft Academic Search

The need for enhanced tactical force protection capabilities is evidenced from our recent experiences in Iraq and Afghanistan and occurs wherever U.S. Forces maintain a forward presence in a potentially hostile environment. Levels of force protection proficiency vary widely from combat units whose mission is to close with and destroy the enemy to combat support\\/combat service support units performing maintenance

Eugene Stockel; Jon C. Moneyhun

2004-01-01

177

The Missing Climate Forcing  

Microsoft Academic Search

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

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

1997-01-01

178

Force Concept Inventory: Forces and Speed  

NSDL National Science Digital Library

A rocket drifts sideways in outer space from point "a" to point "b" as shown in the animations. The rocket is subject to no outside forces. Starting at position "b", the rockets's engine is turned on and produces a constant thrust (force on the rocket) at right angles to the line "ab". The constant thrust is maintained until the rocket reaches a point "c" in space. At point "c" the rocket's engine is turned off and the thrust immediately drops to zero.

Christian, Wolfgang; Belloni, Mario

2006-01-13

179

International migration, international relations and foreign policy.  

PubMed

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

Mitchell, C

1989-01-01

180

U.S. Transport Task Force 2010  

SciTech Connect

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.

Diamond, P.H.

2011-09-21

181

Forcing mechanisms of the Indian Ocean monsoon  

Microsoft Academic Search

Sediments in the Arabian Sea provide biological, biogeochemical and lithogenic evidence of past changes in the Indian Ocean summer monsoon winds. For the past 350,000 years, this system has been externally forced by cyclical changes in solar radiation, and internally phase-locked to the transport of latent heat from the southern subtropical Indian Ocean to the Tibetan Plateau. In contrast to

Steven Clemens; Warren Prell; David Murray; Graham Shimmield; Graham Weedon

1991-01-01

182

Efficacy of climate forcings  

NASA Astrophysics Data System (ADS)

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.

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

183

Actin-based propulsive forces and myosin-II-based contractile forces in migrating Dictyostelium cells.  

PubMed

It has been suggested that myosin II exerts traction forces at the posterior ends and retracting pseudopodia of migrating cells, but there is no direct evidence. Here, using a combination of total internal reflection fluorescence (TIRF) microscopy and force microscopy with a high spatial resolution of approximately 400 nm, we simultaneously recorded GFP-myosin II dynamics and traction forces under migrating Dictyostelium cells. Accumulation of filamentous myosin II and a subsequent increase in traction forces were detected in pseudopodia just before retraction. In the case of motorless myosin II, traction forces did not increase after accumulation, suggesting that the source of the retraction force is the motor activity of accumulated myosin II. Simultaneous recording of F-actin and traction forces revealed that traction forces were exerted under spot-like regions where F-actin accumulated. Cells migrated in a direction counter to the sum of the force vectors exerted at each spot, suggesting that the stress spots act as scaffolds to transmit the propulsive forces at the leading edge generated by actin polymerization. PMID:18388319

Iwadate, Yoshiaki; Yumura, Shigehiko

2008-04-15

184

International Schools for International People.  

ERIC Educational Resources Information Center

Describes the focus and activities of the 1986 annual European Council of International Schools (ECIS) conference. Outlines ECIS history and the International Baccalaureate curricula widely accepted by universities. Switzerland no longer dominates the international education market, which is alive and flourishing throughout Europe. (MLH)

Bruce, Michael G.

1987-01-01

185

Forces in molecules.  

PubMed

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

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

2007-01-01

186

Higher Ground: Guidelines for the Air Force's Transition to the Space Environment.  

National Technical Information Service (NTIS)

The following study examines some of the major issues facing the Air Force as it transitions from an 'air' to an 'air and space' force. International regimes currently preserve space as a peaceful operating environment. However, given the military advanta...

J. E. Lloyd

1999-01-01

187

Force-Measuring Clamps  

NASA Technical Reports Server (NTRS)

Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications for example, while bonding sensors to substrates or while clamping any sensitive or delicate parts. Many manufacturers of adhesives and sensors recommend clamping at specific pressures while bonding sensors or during adhesive bonding between parts in general. In the absence of a force-measuring clamp, measurement of clamping force can be cumbersome at best because of the need for additional load sensors and load-indicating equipment. One prior method of measuring clamping force involved the use of load washers or miniature load cells in combination with external power sources and load-indicating equipment. Calibrated spring clamps have also been used. Load washers and miniature load cells constitute additional clamped parts in load paths and can add to the destabilizing effects of loading mechanisms. Spring clamps can lose calibration quickly through weakening of the springs and are limited to the maximum forces that the springs can apply. The basic principle of a force-measuring clamp can be implemented on a clamp of almost any size and can enable measurement of a force of almost any magnitude. No external equipment is needed because the component(s) for transducing the clamping force and the circuitry for supplying power, conditioning the output of the transducers, and displaying the measurement value are all housed on the clamp. In other words, a force-measuring clamp is a complete force-application and force-measurement system all in one package. The advantage of unitary packaging of such a system is that it becomes possible to apply the desired clamping force or pressure with precision and ease.

Nunnelee, Mark

2003-01-01

188

Force Limited Vibration Testing  

NASA Technical Reports Server (NTRS)

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

Scharton, Terry; Chang, Kurng Y.

2005-01-01

189

Forces and Interactions  

NSDL National Science Digital Library

Although the purist will state that there are four forces, when explaining observed phenomena at the nanoscale it is very useful to include interactions such as ionic and covalent bonding, hydrogen bonds, Brownian motion, van der Waals forces, thermal vibration, rotation , adhesive and cohesive forces and subcategories of these interactions. Often, the effect of what is observed at any scale (macroscale to nanoscale) is dependent upon the priorities of these forces. For example the interaction between planets is driven by the gravitational force because of the large mass of the objects, The strength of the interaction of planets due to the electrostatic forces exists, but is very small -- overshadowed by the gravitational forces. The opposite is often true at the nanoscale, atoms and molecules are significantly impacted by electrostatic forces - and because of the small mass, minimally impacted by gravitational attraction. So it is just a matter of which force or interaction is the top interaction for any given situation. These modules use many different activities which allow students to evaluate the priority of different forces and interactions with different materials and at different scales.

2012-10-04

190

Qualitative Force Structure Analysis of the Global Mobility Task Force.  

National Technical Information Service (NTIS)

This paper examines the Global Mobility Task Force construct and the optimum force structure needed to implement this vision. The 'United States Air Force Transformation Flight Plan' provides the strategic guidance for the Global Mobility Task Force const...

M. J. Logar

2003-01-01

191

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)

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.

Loup, Fernando

2006-10-01

192

International Perspectives.  

ERIC Educational Resources Information Center

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)

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

1998-01-01

193

Coulomb force as an entropic force  

NASA Astrophysics Data System (ADS)

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.

Wang, Tower

2010-05-01

194

Physical Pendulum Forces  

NSDL National Science Digital Library

The Physical Pendulum with Forces model displays the gravitational, normal, and friction forces acting on a mass attached to a pivoted rod.  These forces cause the mass to accelerate in the radially and tangentially with respect to pivot.  Although gravity is always downward, friction and normal force change direction in order to keep the mass in the same position on the stick.  The Physical Pendulum Forces model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_mech_newton_PhysicalPendulumForces.jar file will run the program if Java is installed.

Christian, Wolfgang

2010-02-01

195

Relativistic Linear Restoring Force  

ERIC Educational Resources Information Center

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…

Clark, D.; Franklin, J.; Mann, N.

2012-01-01

196

Directional shear force microscopy  

SciTech Connect

We describe a technique, based on shear force microscopy, that allows one to detect shear forces in a chosen direction at the nanometer scale. The lateral direction of an oscillating probe tip is determined by selecting which of the four quadrants are excited on the piezo driver. The shear forces depend directly on this lateral direction if structural anisotropies are present, as confirmed with polydiacetylene monolayers.

Burns, A. R.; Carpick, R. W.

2001-01-15

197

Hydrostatic force sensor  

SciTech Connect

This paper presents a theoretical and experimental investigation of a new kind of force sensor which detects forces by measuring an induced pressure change in a material of large Poisson`s ratio. In this investigation we develop mathematical expressions for the sensor`s sensitivity and bandwidth, and show that its sensitivity can be much larger and its bandwidth is usually smaller than those of existing strain-gage-type sensors. This force sensor is well-suited for measuring large but slowly varying forces. It can be installed in a space smaller than that required by existing sensors.

Evans, M.S.; Stoughton, R.S. [Pacific Northwest Lab., Richland, WA (United States); Kazerooni, H. [Univ. of California, Berkeley, CA (United States)

1994-08-01

198

Central Force JS Model  

NSDL National Science Digital Library

The Central Force JavaScript Model computes the trajectory of a particle acted on by a central force.  The model reads uses a JavaScript mathematical expression parser to read the force and a adaptive step Runge-Kutta 5(4) algorithm to compute the trajectory.  This model is designed to test the speed of the JS parser and the accuracy of the EJS JavaScript ODE solver. The Central Force JS Model was developed using the Easy Java Simulations (EJS) version 5. It is distributed as a ready-to-run html page and requires only a browser with JavaScript support.

Christian, Wolfgang

2013-09-01

199

Forced desorption of polymers from interfaces  

NASA Astrophysics Data System (ADS)

In the past decade it has become possible to directly measure the adsorption force of a polymer in contact with a solid surface using single-molecule force spectroscopy. A plateau force in the force-extension curve is often observed in systems of physisorbed or noncovalently bonded polymers. If a molecule is pulled quickly compared to internal relaxation, then nonequilibrium effects can be observed. Here we investigate these effects using statistical mechanical models and experiments with a spider silk polypeptide. We present evidence that most experiments showing plateau forces are done out of equilibrium. We find that the dominant nonequilibrium effect is that the detachment height hmax(v) increases with pulling speed v. Based on a nonequilibrium model within a master-equation approach, we show the sigmoidal dependence of the detachment height on the pulling speed of the cantilever, agreeing with experimental data on a spider silk polypeptide. We also show that the slope with which the plateau forces detach is given by the cantilever force constant in both theory and experiment.

Staple, Douglas B.; Geisler, Michael; Hugel, Thorsten; Kreplak, Laurent; Jürgen Kreuzer, Hans

2011-01-01

200

Physlet Force Concept Inventory: Gravity and Force  

NSDL National Science Digital Library

The accompanying animation shows a frictionless channel in the shape of a segment of circle with center at "O". The channel has been anchored to a frictionless horizontal table top. Forces exerted by the air are negligible. A ball is shot at high speeds into the channel at "p" and exits at "r".

Christian, Wolfgang; Belloni, Mario

2006-01-13

201

International english  

SciTech Connect

This paper is a presentation to the International Professional Communication Conference on International English. Presidence is taken from the Royal Society of London in 1667 to purify and simplify the English language. Because English has become the most spoken language in the world, the case in herein made to make it plainer and more easily learned. Technical communications is stressed. (FSD).

Amador, M.

1990-01-01

202

International Curriculums.  

ERIC Educational Resources Information Center

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

Neal, Larry L.

203

Why International?  

ERIC Educational Resources Information Center

Discusses the benefits of international programs at community colleges based on the example of Middlesex Community College in Bedford, Massachusetts. Indicates that international programs broaden the perspective of the campus, generate new revenue and positive media exposure, contribute to professional development of faculty and staff, and provide…

Falcetta, Frank M.

1993-01-01

204

Climate forcings and feedbacks  

NASA Technical Reports Server (NTRS)

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.

Hansen, James

1993-01-01

205

Projectiles and aerodynamic forces  

Microsoft Academic Search

Most elementary works on physics contain something about the motion of projectiles which, it is commonly assumed, are acted on only by gravity. Yet even on balls used in various games the aerodynamic forces are rarely completely negligible (Daish 1972, especially chs 6 and 12). As for bullets and artillery projectiles, the force of air resistance on them is commonly

H L Armstrong

1984-01-01

206

LASNEX: pondermotive force algorithm  

Microsoft Academic Search

The new algorithm used to calculate the ponderomotive force in LASNEX is discussed. The algorithm is shown to be identical with the corresponding analytic expression when the WKB solution for the fields in a plane-parallel medium is used. LASNEX calculations performed to check the ponderomotive force algorithm are described. 2 figures.

J. A. Harte; G. B. Zimmerman

1977-01-01

207

Force Protection Sensor Selector  

Microsoft Academic Search

Force protection sensor selector (FPSS) is a computer application that assists security personnel in the selection of exterior intrusion detection systems best suited for maintaining force protection and physical security at a site. The FPSS software ranks intrusion detection system (IDS) suitability on the basis of known environmental impacts on sensor systems and expected operating conditions. The ranking is done

Lindamae Peck; Richard Bates

2006-01-01

208

Lingual force detection system  

Microsoft Academic Search

The tongue is an organ of great significance in the processes of both swallowing and speech. Any disorder of the tongue's function (dysphagia, lateral sclerosis), with regard especially to the forces it produces, can drastically impair an individual by leaving them unable to swallow or talk. Up to this point, few systems have been created to quantitatively measure tongue force.

Amit Sangave; Thomas Manuccia; Matthew Kay; Vesna Zderic

2008-01-01

209

Force concept inventory  

NSDL National Science Digital Library

This article reports the rationale, design, validation, and uses of the "Force Concept Inventory," an instrument to assess students' beliefs on force. Results and implications of two studies that compared the inventory with the "Mechanics Baseline" are included. The article includes a copy of the instrument.

Hestenes, David; Wells, Malcolm; Swackhamer, Gregg

2005-10-27

210

Mobile Strike force 2010.  

National Technical Information Service (NTIS)

This paper describes the Mobile Strike Force (MSF) 2010 analysis. This analysis provided input to the TRADOC Commander and the Chief of Staff of the Army to support decisions regarding FORCE XXI development and to the Battle Laboratory Integration and Tec...

T. J. Bailey S. R. George R. R. Groover B. P. Sheehan M. R. Anderson

1994-01-01

211

Dispersion Forces and Duality  

Microsoft Academic Search

We formulate a symmetry principle on the basis of the duality of electric and magnetic fields and apply it to dispersion forces. Within the context of macroscopic quantum electrodynamics, we rigorously establish duality invariance for the free electromagnetic field in the presence of causal magnetoelectrics. Dispersion forces are given in terms of the Green tensor for the electromagnetic field and

Stefan Yoshi Buhmann; Stefan Scheel; Hassan Safari; Dirk-Gunnar Welsch

2009-01-01

212

Physclips: Coriolis Forces  

NSDL National Science Digital Library

This web page provides an introduction to coriolis forces. It includes topics such as the motion of wind and ocean currents, the rotation of the Earth, and forces. Diagrams are integrated with text to promote understanding of important concepts. This tutorial is part of the PhysClip collection of web-based resources on introductory mechanics, electricity, and magnetism.

Wolfe, Joe

2009-06-18

213

Elementary Particles and Forces.  

ERIC Educational Resources Information Center

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…

Quigg, Chris

1985-01-01

214

``Force-free'' electrophoresis?  

NASA Astrophysics Data System (ADS)

When a colloidal particle is exposed to an externally applied electric field, it acquires an electrophoretic velocity, resulting from fluid slip occurring across the Debye screening layer. When the field is uniformly applied, it is usually assumed that the net neutrality of the combined particle-layer system implies that the net electric force acting on it must vanish. This assumption of ``force-free'' phoretic motion has been employed extensively to describe electrophoresis in both unbounded and bounded fluid domains [J. L. Anderson, Annu. Rev. Fluid Mech. 21, 61 (1989)]. A careful inspection reveals here that this intuitive premise may fail when the fluid domain is bounded, in which case a nonzero electric force (resembling dielectrophoretic forces in nonuniformly applied fields) may actually exist. Such forces (represented via surface integrals of Maxwell stresses) result in particle motion above and beyond the one driven by the phoretic slip mechanism. A positive demonstration for the existence of a such a force is provided for a standard sphere-wall configuration, where the applied field acts parallel to the wall. In that scenario, particle motion consists of a (familiar) slip-driven contribution parallel to the wall, together with a superimposed force-driven drift away from the wall. An analogy with pressure forces occurring at incompressible and inviscid potential flows is presented.

Yariv, Ehud

2006-03-01

215

International Water Association  

NSDL National Science Digital Library

A worldwide organization of water professionals, the International Water Association's (IWA) Web site illustrates its commitment "to help water professionals create innovative, pragmatic, and sustainable solutions to challenging global water needs." Visitors can discover IWA's many activities from conferences and forums to task forces. Researchers can discover the various IWS groups that specialize in topics including Source Management, Education, Health, Management Training, and Water Quality Management. Although many of the publications are restricted to members, educators and students can read reports from the Sustainability in Water Sector and abstracts from IWA journals.

2003-01-01

216

Conservative entropic forces  

NASA Astrophysics Data System (ADS)

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

Visser, Matt

2011-10-01

217

International Education--What's in a Name?  

ERIC Educational Resources Information Center

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

Parker, Walter C.

2008-01-01

218

International Migration  

NSDL National Science Digital Library

This Website, Push and Pull Factors of International Migration, features background and preliminary research data from a joint project of Eurostat and The Netherlands Interdisciplinary Demographic Institute the goal of which is to "improve understanding of the direct and indirect causes and mechanisms of international migration to the European Union from an internationally comparative perspective. The project is an effort to respond to the fact that "international migration flows have increased in magnitude and complexity over the past decades." Separate sections of the site provide information on the aim, objectives, and approach of the project; the research design; as well as a summary of first results on recent migration, migration motives, migration networks, and migration intentions; and further bibliographic and Web-based resources. The project is under the auspices of the Commission of the European Communities.

219

Transparency International  

NSDL National Science Digital Library

Transparency International (TI) is a non-governmental organization concerned with "increasing governmental accountability and curbing both international and national corruption." Best known for its Corruption Perceptions Index (see the February 26, 1998 Scout Report for Business and Economics), Transparency International also offers a host of other corruption-related resources, including the TI Bribers's Pay Survey and TI Bribers's Pay Index, two resources on bribe-paying in international trade; an anti-corruption directory which serves as a reference guide to efforts in central and eastern European countries to support anti-corruption programs; working papers; and other publications. Also worthy of note is TI's ten-point program directed at pressuring the World Bank Organization to help strengthen its anti-corruption programs. The layout of the TI Website is somewhat confusing, but most of the organization's research efforts can be found in the Info Centre.

220

Turbomachinery rotor forces  

NASA Technical Reports Server (NTRS)

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

Arndt, Norbert

1988-01-01

221

ILO - International Migration Programme.  

PubMed

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

Boudraa, Miriam

2011-01-01

222

Manual discrimination of force  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

223

Dilatonic Entropic Force  

NASA Astrophysics Data System (ADS)

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

Sakalli, I.

2011-08-01

224

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

PubMed

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

Ouattara, M; Sen, P; Thomson, M

1998-11-01

225

Linearly Forced Isotropic Turbulence.  

National Technical Information Service (NTIS)

Stationary isotropic turbulence is often studied numerically by adding a forcing term to the Navier-Stokes equation. This is usually done for the purpose of achieving higher Reynolds number and longer statistics than is possible for isotropic decaying tur...

T. S. Lundgren

2004-01-01

226

Linearly Forces Isotropic Turbulence.  

National Technical Information Service (NTIS)

Stationary isotropic turbulence is often studied numerically by adding a forcing term to the Navier-Stokes equation. This is usually done for the purpose of achieving higher Reynolds number and longer statistics than is possible for isotropic decaying tur...

T. S. Lundgren

2003-01-01

227

Globalization Task Force Report.  

National Technical Information Service (NTIS)

Since the last meeting of the President's National Security Telecommunications Advisory Committee (NSTAC) in June 1999, the Globalization Task Force (GTF)1 has concentrated its efforts on national security and emergency preparedness (NS/EP) issues related...

2000-01-01

228

Cohesion and Interparticle Forces.  

National Technical Information Service (NTIS)

A number of properties connected with the cohesive behavior of a powder have been analyzed and related to the interparticle forces. The tensile strength and cohesion of compacted systems, and the cohesion of an aerated system, have been studied experiment...

E. F. Hobbel

1988-01-01

229

Forces in the Earth  

NSDL National Science Digital Library

This page discusses the three main forces (compression, tension, and shear) that drive deformation within the Earth. Students can click on an animation to see illustrations of each type. Links to a glossary are embedded in the text.

230

Forces in Motion.  

ERIC Educational Resources Information Center

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)

Goodsell, David; And Others

1995-01-01

231

Russian Nuclear Forces, 2010  

Microsoft Academic Search

With or without a follow-on agreement to START, the number of warheads in the Russian nuclear arsenal continues to shrink. But that doesn't mean Moscow has given up modernizing its strategic nuclear forces.

Robert S. Norris; Hans M. Kristensen

2010-01-01

232

Metamaterials enhancing optical forces  

NASA Astrophysics Data System (ADS)

The interaction between light and matter involves not only an energy transfer, but also the transfer of linear momentum. In everyday life applications this linear momentum of light is too small to play any significant role. However, in nanoscale dimensions, the associated optical forces start to play an increasingly important role. These forces are, e.g., large enough for exiting experiments in the fields of cavity-optomechanics, laser cooling and optical trapping of small particles. Recently, it has been suggested that optical gradient forces can also be employed for all-optical actuation in micro- and nanophotonic systems. The typical setup consists of two slab waveguides positioned in each others vicinity such that they are coupled through the interaction of the evanescent tails. Although the gradient forces between these waveguides can be enhanced considerably using electromagnetic resonators or slow-light techniques, the resulting displacements remain relatively small. In this contribution, we present an alternative approach to enhance optical gradient forces between waveguides using a combination of transformation optics and metamaterials. Our design starts from the observation that gradient forces exponentially decay with the separation distance between the waveguides. Therefore, we employ transformation optics to annihilate the apparent distance for light between the waveguides. Analytical calculations confirm that the resulting forces indeed increase when such an annihilating cladding is inserted. Subsequently, we discuss the metamaterial implementation of this annihilating medium. Such lensing media automatically translate into anisotropic metamaterials with negative components in the permittivity and permeability tensors. Our full-wave numerical simulations show that the overall amplification is highly limited by the loss-tangent of the metamaterial cladding. However, as this cladding only needs to operate in the near-field for a specific polarization, we can also consider single-negative metamaterial implementations. We finally demonstrate that in this way metamaterials can support optical forces enhanced by more than 200 times [Phys. Rev. Lett. 110, 057401 (2013)].

Ginis, Vincent; Tassin, Philippe; Soukoulis, Costas M.; Veretennicoff, Irina

2014-05-01

233

Assessing the industry using Porter's five forces.  

PubMed

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

2014-01-01

234

The Missing Climate Forcing  

NASA Astrophysics Data System (ADS)

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.

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

1997-02-01

235

Trends of Measured Climate Forcing Agents  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

236

Trends of measured climate forcing agents  

PubMed Central

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.

Hansen, James E.; Sato, Makiko

2001-01-01

237

Processes of Internal and International Migration from Chitwan, Nepal  

PubMed Central

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.

Bohra, Pratikshya; Massey, Douglas S.

2011-01-01

238

Sensorimotor mapping for anticipatory grip force modulation.  

PubMed

During object manipulation, predictive grip force modulation allows compensation for inertial forces induced by the object's acceleration. This coupling between grip force (GF) and load force (LF) during voluntary movements has demonstrated high levels of complexity, adaptability, and flexibility under many loading conditions in a broad range of experimental studies. The association between GF and LF indicates the presence of internal models underlying predictive GF control. The present experiment sought to identify the variables taken into account during GF modulation at the initiation of a movement. Twenty subjects performed discrete point-to-point movements under normal and hypergravity conditions induced by parabolic flights. Two control experiments performed under normal gravitational conditions compared the observed effect of the increase in gravity with the effects of a change in movement kinematics and a change in mass. In hypergravity, subjects responded accurately to the increase in weight during stationary holding but overestimated inertial loads. During dynamic phases, the relationship between GF and LF under hypergravity varied in a manner similar to the control test in which object mass was increased, whereas a change in movement kinematics could not reproduce this result. We suggest that the subjects' strategy for anticipatory GF modulation is based on sensorimotor mapping that combines the perception of the weight encoded during stationary holding with an internal representation of the movement kinematics. In particular, such a combination reflects a prior knowledge of the unequivocal relationship linking mass, weight, and loads under the invariant gravitational context experienced on Earth. PMID:20573975

Crevecoeur, Frédéric; Thonnard, Jean-Louis; Lefèvre, Philippe

2010-09-01

239

International Security  

NSDL National Science Digital Library

Maintained by the US Department of State's Office of International Information Programs (OIIP), formerly the USIA, this site is among the four US Policy topics covered in depth on the OIIP site. It contains a special Response to Terrorism section that presents relevant official policy texts, photo galleries, key documents, and in-focus topics such as Investigation, US Muslim Community, and Economic Issues. Other features of the International Security site include several other Issues in Focus (i.e., Arms Control and Non-Proliferation), Regions in Focus, Links to other organizations and agencies, as well as to the Electronic Journal of the Department of State, U.S. Foreign Policy Agenda.

2001-01-01

240

Joint Technical Architecture - Air Force.  

National Technical Information Service (NTIS)

This Air Force instruction (AFI) implements Air Force Policy Directive (AFPD) 33-1, Command, Control, Communications, and Computer (C4) Systems. It mandates the Joint Technical Architecture - Air Force (JTA-AF) and describes implementation details, roles,...

2000-01-01

241

Internal force field in proteins seen by divergence entropy  

PubMed Central

The characteristic distribution of non-binding interactions in a protein is described. It establishes that hydrophobic interactions can be characterized by suitable 3D Gauss functions while electrostatic interactions generally follow a random distribution. The implementation of this observation suggests differentiated optimization procedure for these two types of interactions. The electrostatic interaction may follow traditional energy optimization while the criteria for convergence shall measure the accordance with 3-D Gauss function.

Marchewka, Damian; Banach, Mateusz; Roterman, Irena

2011-01-01

242

Internal force field in proteins seen by divergence entropy.  

PubMed

The characteristic distribution of non-binding interactions in a protein is described. It establishes that hydrophobic interactions can be characterized by suitable 3D Gauss functions while electrostatic interactions generally follow a random distribution. The implementation of this observation suggests differentiated optimization procedure for these two types of interactions. The electrostatic interaction may follow traditional energy optimization while the criteria for convergence shall measure the accordance with 3-D Gauss function. PMID:21769190

Marchewka, Damian; Banach, Mateusz; Roterman, Irena

2011-01-01

243

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...

244

Flow Visualization of Forced and Natural Convection in Internal Cavities  

SciTech Connect

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.

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

245

International Reports.  

ERIC Educational Resources Information Center

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…

Anderson, Nancy D.; And Others

1994-01-01

246

International Marketplace.  

ERIC Educational Resources Information Center

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…

Wells, Donald A.; And Others

1985-01-01

247

Tie-bar extension-force online monitoring by optical fiber Bragg grating strain sensors  

Microsoft Academic Search

In this paper, a tie-bar extension-force online monitoring system in a tie-bar arch bridge is presented. Optical fiber Bragg\\u000a grating strain sensors are embedded in the tie-bar arch bridge for online monitoring of changes in the state of internal force.\\u000a The relation between the tie-bar extension force measured by optical fiber Bragg grating strain sensors and the internal state\\u000a of

Fu Jun; Yan Xinping; Liu Shengchun

2006-01-01

248

Motion and force control for multiple cooperative manipulators  

NASA Technical Reports Server (NTRS)

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.

Wen, John T.; Kreutz, Kenneth

1989-01-01

249

Teaching International Law: Concepts in International Relations  

ERIC Educational Resources Information Center

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…

Starbird, Caroline; Pettit, Jenny; Singleton, Laurel

2004-01-01

250

Linear force device  

NASA Technical Reports Server (NTRS)

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.

Clancy, John P.

1988-01-01

251

International Economic Institutions, Institutional Complementarities and Institutionalized Linkages. The International Trade Case  

Microsoft Academic Search

This paper analyses the forces at the base of the formation processes of international economic institutions following the fundamental New Institutional Economics (NIE) approach. In particular, the paper assumes that new international economic institutions respond to a principle of procedural rationality. This principle indicates that the formation of institutions takes place in an environment dominated by the bounded rationality of

Maurizio Mistri

2010-01-01

252

Weak Nuclear Forces cause the Strong Nuclear Force  

SciTech Connect

We determine the strength of the weak nuclear force which holds the lattices of the elementary particles together. We also determine the strength of the strong nuclear force which emanates from the sides of the nuclear lattices. The strong force is the sum of the unsaturated weak forces at the surface of the lattices.

Koschmieder, E. L. [Center for Statistical Mechanics, University of Texas at Austin, Austin TX 78712 (United States)

2008-05-29

253

Force Concept Inventory: Forces Acting upon a Moving Object  

NSDL National Science Digital Library

Despite a very strong wind, a tennis player manages to hit a tennis ball with her racquet so that the ball passes over the net and lands in her opponent's court. Consider the following forces: 1. A downward force of gravity. 2. A force by the "hit". 3. A force exerted by the air.

Christian, Wolfgang; Belloni, Mario

2006-01-13

254

Forces and Graphing  

NSDL National Science Digital Library

Use this activity to explore forces acting on objects, practice graphing experimental data, and introduce the algebra concepts of slope and intercept of a line. A wooden 2 x 4 beam is set on top of two scales. Students learn how to conduct an experiment by applying loads at different locations along the beam, recording the exact position of the applied load and the reaction forces measured by the scales at each end of the beam. In addition, students analyze the experiment data with the use of a chart and a table, and model/graph linear equations to describe relationships between independent and dependent variables.

GK-12 Program, Center for Engineering and Computing Education, College of Engineering and Information Technology,

255

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

Federal Register 2010, 2011, 2012, 2013

...Binational Management of Lake of the Woods and Rainy River Watershed The International...of its International Lake of the Woods and Rainy River Watershed Task Force...in the international Lake of the Woods and Rainy River watershed. Task...

2011-07-28

256

International Migration and International Trade.  

National Technical Information Service (NTIS)

The paper reviews the major types of international migration and recent global and regional trends in population movements, as well as conceptual issues and recent trends in the volume of remittance flows. The paper further considers the extent to which t...

S. S. Russell M. S. Teitelbaum

1992-01-01

257

Motive force and centripetal force in Newton's mechanics  

NASA Astrophysics Data System (ADS)

Newton's concept of force was developed over a period of time, starting with a collisional model in his Waste Book, and culminating in his measure of the centripetal force at a point found in De Motu and again in Principia, Book I, Prop. VI. Newton kept developing his force concept, adding to it and making it many faceted. This rich concept of force has often posed difficulties for historians of science [for example, R. S. Westfall, Force in Newton's Physics (MacDonald and American Elsevier, New York, 1971) and J. Herivel, The Background to Newton's Principia (Oxford U.P., New York, 1965)] and others. These difficulties are related to at least six things as follows: (1) lack of understanding that Newton's ``motive force'' is an abbreviation for ``motive quantity of a force,'' so that Newton's ``motive force'' and his ``force'' are not two different types of force. Motive force (motive quantity) is used to quantify force; (2) lack of understanding of Newton's model for instantaneous impulses; (3) lack of understanding that although Newton's motive force has directionality Newton added it as a scalar in his analysis of uniform circular motion; (4) lack of understanding of Newton's polygon model; (5) lack of understanding that Newton's measure of the motive value of a force, the motive force, was always used to obtain a comparative measure of forces in his early mechanics; and (6) lack of understanding that Newton's Prop. VI measure of centripetal force at a point permitted Newton to bring the time dimension into his motive force concept, thus developing it into something very close to our modern definition of force. This paper analyzes Newton's development of his motive force concept, and discusses the difficulties that some scholars have had with various aspects of this concept.

Erlichson, Herman

1991-09-01

258

Antiphospholipid Syndrome Clinical Research Task Force report.  

PubMed

The Antiphospholipid Syndrome (APS) Clinical Research Task Force (CRTF) was one of six Task Forces developed by the 13(th) International Congress on Antiphospholipid Antibodies (aPL) organization committee with the purpose of: a) evaluating the limitations of APS clinical research and developing guidelines for researchers to help improve the quality of APS research; and b) prioritizing the ideas for a well-designed multicenter clinical trial and discussing the pragmatics of getting such a trial done. Following a systematic working algorithm, the Task Force identified five major issues that impede APS clinical research and the ability to develop evidence-based recommendations for the management of aPL-positive patients: (1) aPL detection has been based on partially or non-standardized tests, and clinical (and basic) APS research studies have included patients with heterogeneous aPL profiles with different clinical event risks; (2) clinical (and basic) APS research studies have included a heterogeneous group of patients with different aPL-related manifestations (some controversial); (3) thrombosis and/or pregnancy risk stratification and quantification are rarely incorporated in APS clinical research; (4) most APS clinical studies include patients with single positive aPL results and/or low-titer aPL ELISA results; furthermore, study designs are mostly retrospective and not population based, with limited number of prospective and/or controlled population studies; and (5) lack of the understanding the particular mechanisms of aPL-mediated clinical events limits the optimal clinical study design. The Task Force recommended that there is an urgent need for a truly international collaborative approach to design and conduct well-designed prospective large-scale multi-center clinical trials of patients with persistent and clinically significant aPL profiles. An international collaborative meeting to formulate a good research question using 'FINER' (Feasible; Interesting; Novel; Ethical; and Relevant) criteria took place in November 2010. PMID:21303838

Erkan, D; Derksen, R; Levy, R; Machin, S; Ortel, T; Pierangeli, S; Roubey, R; Lockshin, M

2011-02-01

259

Internal Detonations  

Microsoft Academic Search

\\u000a Detonations inside structures present a number of complicating factors. Multiple reflections from walls, floors and ceilings\\u000a interact and enhance the overpressure. In a structure which has few internal walls or partitions such as a parking garage,\\u000a the blast wave reflects from the floor and ceiling. Mach stems form on both surfaces. As the triple points grow away from\\u000a each surface,

Charles E. Needham

260

International cooperation.  

PubMed

As the most densely populated country in the world, China actively conducts international exchanges and cooperation. It takes every opportunity to publicize its family planning policies and practices during international forums. Moreover, the country's State Family Planning Commission has been collaborating with the United Nations Population Fund in implementing health and family planning programs. This program covers public awareness campaigns, technical services, sex education for the youth, and social marketing. For years, China has also been cooperating with WHO in the area of family planning and reproductive health, and has established partnership with the Japanese Organization for International Cooperation in Family Planning. In addition, the State Family Planning Commission has worked with the Public Media Center of the US as well as with the Rockefeller Foundation and Ford Foundation in introducing "contraceptive methods by informed choice" and "male participation in family planning" in the rural areas of the country. China has also worked closely with many other developing countries on population issues. In October 1998, China collaborated with the Partners in Population and Development for a reporting mission that was attended by journalists from 11 countries. PMID:12349160

1999-04-01

261

Technology and the Sales Force  

Microsoft Academic Search

This paper explores the application of sales force technology by Amach, Inc. a Detroit based medical device firm. Sales force technology represents a variety of dynamic tools that can help the sales force. While these tools cannot replace the salesperson and generate deals from customers, they can enhance efficiency and effectiveness levels. Sales force technology can range from computer laptops,

Tony Carter

2002-01-01

262

Reduction in Force.  

ERIC Educational Resources Information Center

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

Wood, R. Craig

263

Optically induced 'negative forces'  

NASA Astrophysics Data System (ADS)

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'.

Dogariu, Aristide; Sukhov, Sergey; Sáenz, José

2013-01-01

264

An alternating force magnetometer  

Microsoft Academic Search

A novel instrument for measuring the magnetic moment of a small specimen of material is formed by applying AC techniques to the traditional force magnetometer (or Faraday magnetometer). The action of the instrument is analysed and an attempt is made to mention all the sources of error and practical difficulty that arise. The new instrument is closely related to the

R. Reeves

1972-01-01

265

``Force,'' ontology, and language  

Microsoft Academic Search

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

David T. Brookes; Eugenia Etkina

2009-01-01

266

The fifth force  

SciTech Connect

We present a phenomenological description of the ''fifth force'' which focuses on the implications of the existing data from satellite and geophysical measurements of gravity, the Eoetvoes experiment, decays into hyperphotons, and the energy-dependence of the K/sup 0/ - anti K/sup 0/ parameters.

Fischbach, E.; Sudarsky, D.; Szafer, A.; Talmadge, C.; Aronson, S.H.

1986-01-01

267

Forced Spring Systems  

NSDL National Science Digital Library

Created by Lang Moore and David Smith for the Connected Curriculum Project, the purpose of this module is to explore the effects of an external driving force on a simple linear oscillator, damped or undamped. This is one within a much larger set of learning modules hosted by Duke University.

Moore, Lang; Smith, David

2010-07-20

268

Forces in epithelial origami.  

PubMed

Recent efforts examining forces during morphogenesis suggest a role for mechanical crosstalk between epithelium and mesenchyme in tissue patterning. Reporting in Science, Shyer et al. (2013) show that differences between the mechanical properties of the developing intestinal epithelium and surrounding smooth muscle fold the epithelium into villi via mucosal buckling. PMID:24091007

Nelson, Celeste M

2013-09-30

269

Orbital Forces: Teacher Page  

NSDL National Science Digital Library

This activity demonstates orbital motions and forces using a tennis ball swung by a ribbon (this activity should be done outside). The Teacher Page contains background information, tennis ball preparation instructions, and wrap up information. This activity is part of Exploring Planets in the Classroom's Planetary Properties series.

270

Orbital Forces: Student Page  

NSDL National Science Digital Library

This activity teaches students about orbital motions and forces using a tennis ball swung by a ribbon. Students answer the question "What happens when you let the ball go?" Background information, activity procedures, and key words are provided. This activity is part of Exploring Planets in the Classroom's Planetary Properties series.

271

``Force,'' ontology, and language  

NASA Astrophysics Data System (ADS)

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.

Brookes, David T.; Etkina, Eugenia

2009-06-01

272

Cohesion and Interparticle Forces.  

National Technical Information Service (NTIS)

In the investigation a number of properties connected with the cohesive behavior of a powder have been analyzed and related to the interparticle forces. The tensile strength and cohesion of compacted systems, and the cohesion of an aerated system, were th...

E. F. Hobbel

1988-01-01

273

The Force of Ideas  

ERIC Educational Resources Information Center

"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…

Ascher, Carol

2005-01-01

274

Molecular Recognition Force Microscopy  

Microsoft Academic Search

Atomic force microscopy (AFM), developed in the late eighties to explore atomic details on hard material surfaces, has evolved to an imaging method capable of achieving fine structural details on biological samples. Its particular advantage in biology is that the measurements can be carried out in aqueous and physiological environment, which opens the possibility to study the dynamics of biological

Peter Hinterdorfer

2004-01-01

275

Reduction in Force.  

ERIC Educational Resources Information Center

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

Phay, Robert

276

Forces in nonlinear media  

NASA Astrophysics Data System (ADS)

I investigate the properties of forces on bodies in theories governed by the generalized Poisson equation ?(|?| /a0)?] ? G?, for the potential ? produced by a distribution of sources ?. This equation describes, inter alia, media with a response coefficient, ?, 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.

Milgrom, Mordehai

2002-02-01

277

Measuring Your Force  

ERIC Educational Resources Information Center

This article talks about the force behind education leaders. With all the challenges facing public education today, it is difficult to remain focused and to remember why one chartered this particular leadership course. Perhaps someone respected encouraged one to take this path long ago. Perhaps this kind of service to the nation and its future…

Gee, David E.

2005-01-01

278

Pulleys and Force  

NSDL National Science Digital Library

In this activity, learners explore the concept of force and how pulleys are used in everyday life to make work easier. Learners examine different uses for pulleys, the impact of multiple pulleys, and identify pulley use in school and their community. Learners test the ability to move weights using one, two and three pulleys in a series.

Ieee

2013-08-30

279

Brute Force Microstates Model  

NSDL National Science Digital Library

The Brute Force Microstates model considers an isolated system consisting of N identical, non-interacting quantum particles. We wish to determine the total number of system microstates accessible to the system with energy E and hence the entropy.   For distinguishable particles, the simplest brute force method that can be devised involves N nested loops, each over the list of single particle energy levels. This results in a computational scheme that scales exponentially with the system size. Still, this is an instructive method to apply because it shows the rapid increase in the number of microstates for moderate N, and the corresponding exponential increase in computational time. The model displays the computation time as users to vary the number of particles N and the total energy E. The Brute Force Microstates model was developed by Wolfgang Christian, Trisha Salagaram, and Nithaya Chetty using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_stp_BruteForceMicrostates.jar file will run the program if Java is installed.

Christian, Wolfgang; Salagaram, Trisha; Chetty, Nithaya

2011-07-30

280

Grinding forces and energy  

Microsoft Academic Search

Grinding forces and energy play an important role in all abrasive machining operations. While specific grinding energy may be obtained from workpiece dynamometer values or by measuring spindle power, care must be exercised in converting dynamometer reading into power consumed. This is particularly true for operations involving a large ratio of wheel depth of cut to wheel diameter or when

K. Brach; D. M. Pai; E. Ratterman; M. C. Shaw

1988-01-01

281

Grinding forces and energy  

Microsoft Academic Search

Grinding forces and energy plan an important role in all abrasive machining operations. While specific grinding energy may be obtained from workpiece dynamometer values or by measuring spindle power, care must be exercised in converting dynamometer reading into power consumed. This is particularly true for operations involving a large ratio of wheel depth of cut to wheel diameter or when

K. Brach; D. M. Pai; E. Ratterman; M. C. Shaw

1987-01-01

282

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

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;…

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

283

Intermolecular Forces: A Jigsaw Activity  

NSDL National Science Digital Library

This jigsaw activity is designed as a cooperative learning activity used to introduce the idea of intermolecular forces. Intermolecular forces are the types of attractive forces that occur between molecules in a solid, liquid, or gas. Each force causes different physical properties of matter. Each member of the group will become an expert on one type of force and then teach the rest of the group.

Edu., Boise S.

2011-09-20

284

Schooling, Labor-Force Quality, and the Growth of Nations  

Microsoft Academic Search

Direct measures of labor-force quality from international mathematics and science test scores are strongly related to growth. Indirect specification tests are generally consistent with a causal link: direct spending on schools is unrelated to student performance differences; the estimated growth effects of improved labor-force quality hold when East Asian countries are excluded; and, finally, home-country quality differences of immigrants are

Eric A. Hanushek; Dennis D. Kimko

2000-01-01

285

Investigation of Calibrating Force Transducer Using Sinusoidal Force  

SciTech Connect

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.

Zhang Li [School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing (China); Key Laboratory for Metrology, Changcheng Institute of Metrology and Measurement (CIMM), Beijing 100095 (China); Wang Yu; Zhang Lizhe [Key Laboratory for Metrology, Changcheng Institute of Metrology and Measurement (CIMM), Beijing 100095 (China)

2010-05-28

286

Expanding the role of internal facility assessments  

SciTech Connect

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

Kolpa, R.L.; Levenson, J.B. [Argonne National Lab., IL (United States); Weaver, M.A. [Headquarters Air Force Materiel Command, Wright-Patterson AFB, OH (United States)

1996-05-01

287

Microrheology of cells with magnetic force modulation atomic force microscopy.  

PubMed

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 ks(f) = ? + ?(f/f[combining macron])(?) (? = 7.6 × 10(-4) N m(-1), ? = 1.0 × 10(-4) N m(-1), f[combining macron] = 1 Hz, ? = 0.6), where the coefficient ? = 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 ?N s m(-1) for indentation depths ranging between 1.0 ?m and 2.0 ?m. PMID:24651941

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

2014-03-01

288

Mass effects and internal space geometry in triatomic reaction dynamics  

SciTech Connect

The effect of the distribution of mass in triatomic reaction dynamics is analyzed using the geometry of the associated internal space. Atomic masses are appropriately incorporated into internal coordinates as well as the associated non-Euclidean internal space metric tensor after a separation of the rotational degrees of freedom. Because of the non-Euclidean nature of the metric in the internal space, terms such as connection coefficients arise in the internal equations of motion, which act as velocity-dependent forces in a coordinate chart. By statistically averaging these terms, an effective force field is deduced, which accounts for the statistical tendency of geodesics in the internal space. This force field is shown to play a crucial role in determining mass-related branching ratios of isomerization and dissociation dynamics of a triatomic molecule. The methodology presented can be useful for qualitatively predicting branching ratios in general triatomic reactions, and may be applied to the study of isotope effects.

Yanao, Tomohiro; Koon, Wang S.; Marsden, Jerrold E. [Control and Dynamical Systems, MC 107-81, California Institute of Technology, Pasadena, California 91125 (United States)

2006-05-15

289

Force Feedback Joystick  

NASA Technical Reports Server (NTRS)

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.

1997-01-01

290

Projectiles and aerodynamic forces  

NASA Astrophysics Data System (ADS)

Most elementary works on physics contain something about the motion of projectiles which, it is commonly assumed, are acted on only by gravity. Yet even on balls used in various games the aerodynamic forces are rarely completely negligible (Daish 1972, especially chs 6 and 12). As for bullets and artillery projectiles, the force of air resistance on them is commonly many times that of gravity (Smith 1962). What purpose, then, is supposed to be served by presenting students with such unphysical notions and asking them to spend time working out conundrums about such matters? Warren (1965) has commented on the lack of realism in many parts of school physics, but does not seem to have said much about this example. The author's purpose is to find simple ways of taking into account the air resistance on projectiles, at least approximately.

Armstrong, H. L.

1984-09-01

291

Tracking the Coriolis Force  

NSDL National Science Digital Library

Tracking the Coriolis Force uses the Tracker video analysis tool to model the motion of a ball rolling with constant velocity on a rotating merry-go-round. Video includes the motion of the ball as viewed from the rotating reference frame of the merry-go-round. Using the Coriolis force equation, students build a model of the motion. The zip file contains the activity handout, video and Tracker file. The video comes from YouTube and can be found at http://www.youtube.com/watch?v=LAX3ALdienQ. A talk about this activity from the AAPT Winter Meeting 2013 can be found at http://tinyurl.com/trackerCoriolis. To open the Tracker file, download and run Tracker from http://www.cabrillo.edu/~dbrown/tracker/. Tracker is free.

Cox, Anne

2012-06-16

292

Force Modulator System  

SciTech Connect

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.

Redmond Clark

2009-04-30

293

Atomic force microscopy (AFM).  

PubMed

The atomic force microscope (AFM) is an important tool for studying biological samples due to its ability to image surfaces under liquids. The AFM operates by physical interaction of a cantilever tip with the molecules on the cell surface. Adhesion forces between the tip and cell surface molecules are detected as cantilever deflections. Thus, the cantilever tip can be used to image live cells with atomic resolution and to probe single molecular events in living cells under physiological conditions. Currently, this is the only technique available that directly provides structural, mechanical, and functional information at high resolution. This unit presents the basic AFM components, modes of operation, useful tips for sample preparation, and a short review of AFM applications in microbiology. PMID:18770536

Trache, Andreea; Meininger, Gerald A

2008-02-01

294

Suicide and Forced Marriage  

PubMed Central

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.

Pridmore, Saxby; Walter, Garry

2013-01-01

295

ACCION International  

NSDL National Science Digital Library

Part of the ongoing debate about the process of globalization throughout both the developed and developing world is that a good deal of the world's population continues to grow poorer and poorer while a number of international transnational corporations continue to increase their share of the world's assets. There have been a number of efforts to combat poverty in the developing world, including the highly publicized and generally well-received efforts of the Grameen Bank in Bangladesh. One such nonprofit program that has successfully been transplanted from the developing world to the developed world is the ACCION International program of microlending. On its homepage, visitors can learn about the organization's various programs designed to raise people out of poverty through microlending, and also read some key statistics behind its work. For those looking for more detailed information, there is also a publications area, where visitors may download works on topic such as the sustainability of such programs and various "how to" manuals for microentrepreneurs. Many of the publications are available at no charge, and a number of them are also available in Spanish. Finally, visitors may also sign up to receive the ACCION e-News as well.

296

Force reflection with compliance control  

NASA Technical Reports Server (NTRS)

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.

Kim, Won S. (inventor)

1993-01-01

297

Understanding forced flow  

SciTech Connect

Forced flow is an important concept and describes conditions within queues forming behind breakdown points such as demonstrated at the Rundberg Lane merge point. Although the LOS F designation can be used to describe the merge point, as well as the operations within the queue, that does not mean bottleneck flows are substantially less than capacity. Flows substantially less than capacity can occur within queues. Flows measured within queues should not be confused with capacity flows.

Urbanik, T. II

1986-10-01

298

Exploring Forces: Static Electricity  

NSDL National Science Digital Library

In this activity, learners investigate what happens when you build up static electricity on plastic balls. Learners discover that electrostatic forces cause smaller balls to suspend in a tube, while larger balls fall to the bottom. This activity shows learners that size can affect the way a material behaves. This activity is a great way to talk about how different things behave at the nanoscale.

Network, Nanoscale I.; Sciencenter

2010-01-01

299

Ultrasonic Force Microscopies  

NASA Astrophysics Data System (ADS)

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.

Kolosov, Oleg; Briggs, Andrew

300

Shear Forms Force Chains  

NSDL National Science Digital Library

This annotated image from the American Physical Society presents the results of an experiment in which small photoelastic disks on a tray are squeezed in one direction and expanded in the perpendicular direction. The site includes images made using crossed polarizers, and the birefringence of the discs reveals the forces inside them. The site includes two images, a video, and a brief description of the experiment.

2009-01-28

301

Atomic Force Microscopy  

NSDL National Science Digital Library

This website contains a series of videos describing the operation of Atomic Force Microscopes. These videos include outlines of microscopy, models of AFM's, and examples of the operation and output of real microscopes. Also included are student activities and curricular resources for teachers. This is one of a series of similar modules on Nanotechnology produced by the University of Massachusetts Amherst Center on Hierarchical Manufacturing.

2013-02-20

302

Protein folding forces  

Microsoft Academic Search

We investigate the average inter-residue folding forces derived from mutational data of the 15 proteins: barstar, barnase, chymotrypsin inhibitor 2 (CI2), Src SH3 domain, spectrin R16 domain, Arc repressor, apo-azurin, cold shock protein B (cspB), C-terminal domain of ribosomal protein L9 (CTL9), FKBP12, ?-lactalbumin, colicin E7 immunity protein 7 (IM7), colicin E9 immunity protein 9 (IM9), spectrin R17 domain, and

Bengt Nölting; Neema Salimi; Ulrich Guth

2008-01-01

303

Molecular Recognition Force Microscopy  

Microsoft Academic Search

Atomic force microscopy (AFM), developed in the late eighties to explore atomic details on hard material surfaces, has evolved\\u000a to an imaging method capable of achieving fine structural details on biological samples. Its particular advantage in biology\\u000a is that the measurements can be carried out in aqueous and physiological environment, which opens the possibility to study\\u000a the dynamics of biological

Peter Hinterdorfer

304

US nuclear forces, 2011  

Microsoft Academic Search

The Obama administration’s disclosure of its stockpiled and dismantled warhead numbers through September 2009 was, apparently, a “one-time release”; thus, the question remains as to how quickly—or slowly—the country’s arsenal will decline. Turning to the Nuclear Posture Review and New START, the authors assess what can be expected in terms of force levels and counting rules, and they provide clear

Hans M. Kristensen; Robert S. Norris

2011-01-01

305

Uplifting Force: Buoyancy & Density  

NSDL National Science Digital Library

In this investigation, learners explore the force known as buoyancy by placing various objects into water and observing how they behave (for example, which sink more quickly, which float, how much water they displace and how air plays a role in keeping objects afloat). The introduction to the lesson tells the story of Archimedes, the Greek mathematician, who first discovered the law of buoyancy while attempting to determine the mass of a crown of gold.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

306

Drag force scaling for penetration into granular media  

NASA Astrophysics Data System (ADS)

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.

Katsuragi, Hiroaki; Durian, Douglas J.

2013-05-01

307

Modified entropic force  

SciTech Connect

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.

Gao Changjun [National Astronomical Observatories, Chinese Academy of Sciences, Key Laboratory of Optical Astronomy, NAOC, CAS, Beijing, 100012 and Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)

2010-04-15

308

Thermal force drift wave  

NASA Astrophysics Data System (ADS)

A drift instability of a collisional magnetized plasma, unstable due to the Braginskii thermal force but not requiring any direct dissipation such as resistivity or electron inertia, is examined. Unlike conventional drift-modes, the maximum growth rate of the thermal force drift wave (TFDW) is of order the drift frequency, making for a strongly turbulent nonlinear state. A 3D, magnetized two-fluid code is developed to allow the study of both ideal MHD modes as well as lower frequency drift modes. The governing equations are essentially the ideal MHD equations with the inclusion of Hall and thermal force terms in Ohm's law. This set of equations is reduced in a finite ?, long parallel wavelength, and small but significant Larmor radius ordering and tested for shear Alfven waves, parallel sound waves, and drift modes. The code is employed to recover the TFDW instability, to verify the code against the mode's analytic linear characteristics, and to study the nonlinear behavior of the TFDW. The TFDW growth is strongly suppressed by parallel thermal conduction and thus this mode is more likely to be observed in low temperature plasmas.

Hung, C. P.; Hassam, A. B.

2012-02-01

309

Modified entropic force  

NASA Astrophysics Data System (ADS)

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 gD. It is found the Debye acceleration is gD=10-15Nkg-1. This acceleration is very much smaller than the gravitational acceleration 10-4Nkg-1 which is felt by Neptune and the gravitational acceleration 10-10Nkg-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.

Gao, Changjun

2010-04-01

310

Mobile Strike Force - Designing the Force XXI Division.  

National Technical Information Service (NTIS)

This monograph examines the Mobile Strike Force methodology used to design the Force XXI division. This methodology seeks to integrate current and future technologies into the organization to increase versatility and lethality while reducing the size of t...

J. S. Bess

1994-01-01

311

Rapid internal contraction boosts DNA friction  

PubMed Central

Macroscopic objects are usually manipulated by force and observed with light. On the nanoscale, however, this is often done oppositely: individual macromolecules are manipulated by light and monitored with force. This procedure, which is the basis of single-molecule force spectroscopy, has led to much of our quantitative understanding of how DNA works, and is now routinely applied to explore molecular structure and interactions, DNA–protein reactions and protein folding. Here we develop the technique further by introducing a dynamic force spectroscopy set-up for a non-invasive inspection of the tension dynamics in a taut strand of DNA. The internal contraction after a sudden release of the molecule is shown to give rise to a drastically enhanced viscous friction, as revealed by the slow relaxation of an attached colloidal tracer. Our systematic theory explains the data quantitatively and provides a powerful tool for the rational design of new dynamic force spectroscopy assays.

Otto, Oliver; Sturm, Sebastian; Laohakunakorn, Nadanai; Keyser, Ulrich F.; Kroy, Klaus

2013-01-01

312

Force generation in a regrowing eukaryotic flagellum  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

313

Quantification of bacterial adhesion forces using atomic force microscopy (AFM)  

Microsoft Academic Search

This study demonstrated that atomic force microscopy (AFM) can be used to obtain high-resolution topographical images of bacteria, and to quantify the tip–cell interaction force and the surface elasticity. Results show that the adhesion force between the Si3N4 tip and the bacteria surface was in the range from ?3.9 to ?4.3 nN. On the other hand, the adhesion forces at

Herbert H. P. Fang; Kwong-Yu Chan; Li-Chong Xu

2000-01-01

314

Biomolecular force measurements and the atomic force microscope.  

PubMed

The atomic force microscope (AFM) is a surface-sensitive instrument capable of imaging biological samples at nanometer resolution in all environments including liquids. The sensitivity of the AFM cantilever, to forces in the pico Newton range, has been exploited to measure breakaway forces between biomolecules and to measure folding-unfolding forces within single proteins. By attaching specific antibodies to cantilevers the simultaneous imaging of target antigens and identification of antigen-antibody interactions have been demonstrated. PMID:11849957

Allison, David P; Hinterdorfer, Peter; Han, Wenhai

2002-02-01

315

International Verification Organizations.  

National Technical Information Service (NTIS)

Contents: International Verification Organizations: An Introduction; Verification Regimes and the Comprehensive Test Ban: An Assessment; Chemical Weapons; International Verification Organizations: The Case of Conventional Arms Control; International Verif...

E. Morris

1991-01-01

316

International Rivers  

NSDL National Science Digital Library

International Rivers is an organization that opposes the construction of destructive dams on rivers, and they also support communities affected by dams. Their aim is to "protect rivers and promote just and sustainable water and energy development." Visitors will find most of their questions about dams and hydroelectricity can be answered under the "Learn More" tab's FAQ section. Along with each answer, there is most often an article, slideshow, video or other resource to explore further. Some of the pieces examine why there is opposition to large dams, the expense of hydroelectricity, the lack of local jobs produced when a dam is being built in a developing country, and the number of people displaced by dams. Under the "Get Involved" tab, there is a section called "Tools for Educators" that include lessons for introductory learners, intermediate learners, advanced learners, and a "River Educator's Toolkit", which contains lessons on the four major rivers in Asia, Africa, and South America.

317

Forces affecting the substrate in resonant tapping force microscopy  

Microsoft Academic Search

We propose a simple model to describe the interaction of a forced cantilever oscillation with a specimen in a tapping-mode scanning force microscope experiment in order to make a rough estimation of the forces affecting the surface with each touch down of the tip. Assuming weak damping of the cantilever (quality factor of the cantilever between 100 and 1000) and

J. P. Spatz; S. Sheiko; M. Moller; R. G. Winkler; P. Reineker; O. Marti

1995-01-01

318

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

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…

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

319

Bridge Types: Tensile & Compressive Forces  

NSDL National Science Digital Library

Students explore how tension and compression forces act on three different bridge types. Using sponges, cardboard and string, they create models of beam, arch and suspension bridges and apply forces to understand how they disperse or transfer these loads.

Integrated Teaching And Learning Program

320

BIOCHEMISTRY: Force Signaling in Biology  

NSDL National Science Digital Library

Knowledge of the effect of forces on processes in the body, such as muscle contraction, cell locomotion and division, or transport processes, has been limited. This perspective discusses new research into the effect of forces on protein conformation and function.

J. Christof (Technische Universität München;Physik Department); M. Gebhardt (Technische Universität München;Physik Department); Matthias Rief (Technische Universität München/Munich Center for Integrated Protein Science CIPSM;)

2009-06-05

321

Air Force Mentoring: Developing Leaders.  

National Technical Information Service (NTIS)

The Air Force mentoring program should focus on developing subordinate leadership skills. Current Air Force mentoring instructions substitute career building for leadership development. This substitution distracts leaders from maximizing the leadership po...

M. S. Nelson

2003-01-01

322

The Air Force concentrating photovoltaic array program  

NASA Technical Reports Server (NTRS)

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.

Geis, Jack W.

1987-01-01

323

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)

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 ?-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%.

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

2006-10-01

324

Rotational force-feedback wrist  

Microsoft Academic Search

Force-feedback structures are mechanical structures that can generate forces to restore to the user a tactile feeling corresponding to the world in which he is manipulating an object. This paper presents the mechanical design of a 3-rotational-degrees-of-freedom (DOF) wrist able to produce force feedback. The wrist, plugged on an existing 3-translation-DOF Delta force-feedback structure (called Delta haptic device), yields a

Nicolas Cauche; Alain Delchambre; P. Rouiller; Patrick Helmer; Charles Baur; Reymond Clavel

2003-01-01

325

Radiative forcing of climate  

NASA Technical Reports Server (NTRS)

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.

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

326

Automated connector force testing  

NASA Astrophysics Data System (ADS)

A gaging system was developed to modernize the force testing of electrical connectors and components using an IBM personal computer based data acquisition system. Two mechanical fixtures were fabricated using load cells and LVDT transducers to perform the measurements. General purpose software routines perform the operator interface, data acquisition, storage, retrieval, and printout. The system will perform statistical analysis of the part data to aid in evaluation of the manufacturing process. The modular software concept allows the system to be tailored for many other applications using a text editor.

Timmons, L. A.

1992-11-01

327

forced-migration-history  

NSDL National Science Digital Library

This new, UK-based, moderated mailing list serves as a forum for discussions on population displacements in 20th-century European history, "and to explore the inter-relationship of forced migration/resettlement/repatriation with nationalism, state formation and the construction of social identities." While the moderators believe that most of the subscribers will be involved in migration studies, history, geography, demography, and anthropology or sociology, scholars from other fields and different geographical and historical time periods are most welcome. Users will find archived messages and subscription information at the site.

328

Causal entropic forces.  

PubMed

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. PMID:23679649

Wissner-Gross, A D; Freer, C E

2013-04-19

329

Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse  

NASA Astrophysics Data System (ADS)

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.

Bond, T. C.; Zarzycki, C.; Flanner, M. G.; Koch, D. M.

2011-02-01

330

International Education for Wisconsin.  

ERIC Educational Resources Information Center

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)

Moebius, Barbara

1990-01-01

331

Air Force aviation battery programs  

Microsoft Academic Search

Summary form only given. The objective of the Air Force Wright Laboratories' battery program is to develop aviation battery systems which meet Air Force needs; this includes batteries for on-board aircraft, aircraft ground support equipment, life support\\/survival equipment, special operational forces equipment, and tactical weapons. The major thrust areas in the Wright Laboratories battery program are: more electric aircraft (MEA),

R. A. Marsh

1994-01-01

332

Electronic Force Gage for Welders  

NASA Technical Reports Server (NTRS)

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

Bradley, J. W.; Gates, G.

1983-01-01

333

The macroscopic scanning force `microscope'  

Microsoft Academic Search

A homemade, macroscopic version of the scanning force microscope is described. It consists of a cantilever under the influence of external forces, which mimic the tip-sample interactions. The use of this piece of equipment is twofold. First, it serves as a direct way to understand the parts and functions of the scanning force microscope, and thus it is effectively used

Fredy R. Zypman; Claudio Guerra-Vela

2001-01-01

334

International vision and strategy for drug regulatory authority: the PMDA's international vision.  

PubMed

The past several years saw various countries' drug regulatory authorities (DRAs) internationalizing their activities in response to the rapid globalization of pharmaceutical affairs. This is the second surge of internationalization, coming after the first in the 1990s, when the International Conference on Harmonisation (ICH) and the Global Harmonization Task Force were founded. For maximum effect, a DRA needs to carefully strategize its international activities. The significance of international master plans is discussed in relation to the recently published International Vision of Japan's Pharmaceuticals and Medical Devices Agency (PMDA). PMID:22871996

Tominaga, Toshiyoshi; Ando, Yuki; Kondo, Tatsuya

2012-09-01

335

Force reflecting hand controller  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

336

The Force of Friction  

NSDL National Science Digital Library

In the first of two lessons of this curricular unit, students are introduced to the concept of friction as a force that impedes motion when two surfaces are in contact. Student teams use spring scales to drag objects, such as a ceramic coffee cup, along a table top or the floor, measuring the frictional force that exists between the moving object and the surface it slides on. By modifying the bottom surface of the object, students find out what kinds of surfaces generate more or less friction. They also discover that both static and kinetic friction are involved when an object initially at rest is caused to slide across a surface. In the second lesson of the unit, students design and conduct experiments to determine the effects of weight and surface area on friction. They discover that weight affects normal friction (the friction that results from surface roughness), but for very smooth surfaces, the friction due to molecular attraction is affected by contact area.

Engineering K-Ph.d. Program

337

Pairing forces in nuclei  

SciTech Connect

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

Chasman, R.R. [Argonne National Lab., IL (United States). Physics Div.

1996-12-31

338

The Business Roundtable Construction Industry Cost Effectiveness Task Force  

Microsoft Academic Search

The Business Roundtable, an organization founded in 1972 and formed of chief executive officers representing several leading international corporations, has had a major impact on the construction industry in the United States. Member companies are some of the major users of construction services. These business and industry leaders formed task forces to investigate, report, and recommend means by which escalating

Jack Roberts

1987-01-01

339

War Criminals - Testing the Limits of Military Force.  

National Technical Information Service (NTIS)

The coming year will see a critical phase in the international effort to bring peace to Bosnia and Herzegovina. Stabilization Force (SFOR) has an ambitious mission that will continue into summer 1998. Although the war has ended, efforts to build instituti...

F. M. Lorenz

1997-01-01

340

Determining the Future of the US Submarine Force.  

National Technical Information Service (NTIS)

The end of the Cold War has been the watershed event for changes in the international and national security environments that present tremendous implications for the US submarine force. These changes include calls for significant US defense cuts to reap a...

B. T. Howes

1992-01-01

341

The point dipole approximation in magnetic force microscopy  

Microsoft Academic Search

Image interpretation in magnetic force microscopy (MFM) requires detailed information about the internal microstructure of the ferromagnetic tip used for probing the surface microfield of a sample. Since these informations are generally not experimentally available, image interpretation is more speculative than rigorously quantitative at the present time. This theoretical analysis confirms by a simple criterion that MFM image interpretation can

U. Hartmann

1989-01-01

342

Promotion of International Exchange through International Cooperation  

NASA Astrophysics Data System (ADS)

This article describes that Toyohashi University of Technology (TUT) has been receiving international students from all of the world increasingly every year since 1990 and the increase in the international students can be attributed to vigorous international cooperation activities by TUT. International Cooperation Center for Engineering Education (ICCEED) is playing a central role of international cooperation in TUT and two projects implemented by ICCEED in 2007 are introduced.

Homma, Hiroomi

343

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

ERIC Educational Resources Information Center

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

Leitner, Helga; Sheppard, Eric S.

1987-01-01

344

Magnetic microposts as an approach to apply forces to living cells  

PubMed Central

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.

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

345

Bone contact forces on the distal tibia during the stance phase of running.  

PubMed

Although the tibia is a common site of stress fractures in runners, the loading of the tibia during running is not well understood. An integrated experimental and modeling approach was therefore used to estimate the bone contact forces acting on the distal end of the tibia during the stance phase of running, and the contributions of external and internal sources to these forces. Motion capture and force plate data were recorded for 10 male runners as they ran at 3.5-4 m/s. From these data, the joint reaction force (JRF), muscle forces, and bone contact force on the tibia were computed at the ankle using inverse dynamics and optimization methods. The distal end of the tibia was compressed and sheared posteriorly throughout most of stance, with respective peak forces of 9.00+/-1.13 and 0.57+/-0.18 body weights occurring during mid stance. Internal muscle forces were the primary source of tibial compression, whereas the JRF was the primary source of tibial shear due to the forward inclination of the leg relative to the external ground reaction force. The muscle forces and JRF both acted to compress the tibia, but induced tibial shear forces in opposing directions during stance, magnifying tibial compression and reducing tibial shear. The superposition of the peak compressive and posterior shear forces at mid stance may contribute to stress fractures in the posterior face of the tibia. The implications are that changes in running technique could potentially reduce stress fracture risk. PMID:17662295

Sasimontonkul, Siriporn; Bay, Brian K; Pavol, Michael J

2007-01-01

346

International Relations, Social Studies: 6448.20.  

ERIC Educational Resources Information Center

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…

Coe, Rose Marie

347

Collaborative International Education: Reaching across Borders  

ERIC Educational Resources Information Center

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.…

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

2012-01-01

348

Steering in crowded water. [International economics  

Microsoft Academic Search

Basic principles of international economics are reviewed and attention drawn to some commonalities among all countries regardless of political orientation or stage of development. The worldwide economic slowdown has forced all countries to face the problem of shrinking of resources and expanding public demands for services at home and, at the same time, increased linkages abroad. The special relationship of

Blumenthal

1978-01-01

349

International Learning Institutions: Organization, Visions, and Missions  

ERIC Educational Resources Information Center

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,…

Van Hook, Steven R.

2011-01-01

350

Ground reaction forces during treadmill running in microgravity.  

PubMed

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

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

2014-07-18

351

Force\\/velocity and power\\/velocity relationships in squat exercise  

Microsoft Academic Search

The purpose of this study was to describe the force\\/velocity and power\\/velocity relationships obtained during squat exercise.\\u000a The maximal force (F\\u000a 0) was extrapolated from the force\\/velocity relationship and compared to the isometric force directly measured with the aid\\u000a of a force platform placed under the subject's feet. Fifteen international downhill skiers [mean (SD) age 22.4 (2.6)?years,\\u000a height 178 (6.34)?cm

Abderrehmane Rahmani; Fabrice Viale; Georges Dalleau; Jean-René Lacour

2001-01-01

352

Elementary Implantable Force Sensor  

PubMed Central

Implementing implantable sensors which are robust enough to maintain long term functionality inside the body remains a significant challenge. The ideal implantable sensing system is one which is simple and robust; free from batteries, telemetry, and complex electronics. We have developed an elementary implantable sensor for orthopaedic smart implants. The sensor requires no telemetry and no batteries to communicate wirelessly. It has no on-board signal conditioning electronics. The sensor itself has no electrical connections and thus does not require a hermetic package. The sensor is an elementary L-C resonator which can function as a simple force transducer by using a solid dielectric material of known stiffness between two parallel Archimedean coils. The operating characteristics of the sensors are predicted using a simplified, lumped circuit model. We have demonstrated sensor functionality both in air and in saline. Our preliminary data indicate that the sensor can be reasonably well modeled as a lumped circuit to predict its response to loading.

Wachs, Rebecca A.; Ellstein, David; Drazan, John; Healey, Colleen P.; Uhl, Richard L.; Connor, Kenneth A.

2014-01-01

353

Electricity: The Mysterious Force  

NSDL National Science Digital Library

This document examines the mysterious force of electricity. The reading will focus on the physical properties of electricity and discuss topics such as (1) The Atom of Carbon, (2) Static electricity, (3) Magnets are special, (4) Magnetic fields can produce electricity, (5) Batteries produce electricity, (6) Electricity travels in circuits, (7) Secondary energy source, (8) Making electricity, (9) Moving electricity from power plants to homes, (10) Fuels that make electricity, (11) Fossil fuel power plants, (12) Nuclear power plants, (13) Hydropower plants, (14) What's a Watt, and (15) Cost of electricity. The document also depicts illustrations of a bar magnet, turbine generator, transporting electricity, U.S. electricity production, peak demand, and energy efficiency. This resource is structured as an informational booklet to supplement your energy activities or to generate discussion questions.

2008-01-01

354

Forces of Nature  

NSDL National Science Digital Library

These interactive simulations allow students to investigate four of nature's more violent phenomena: volcanoes, earthquakes, hurricanes, and tornadoes. Each simulation begins with a brief written tutorial describing the characteristics and destructive potential of these hazards. Users may then adjust the various factors affecting the occurence of these phenomena (for instance, ocean temperature, humidity, and atmospheric pressure for hurricanes) and observe the results. These simulations are related to the film National Geogrpahic film Forces of Nature ; other links provide access to lesson plans designed to accompany the film and to a list of locations where the film can be seen. There are also links to a preview of the film, fast facts, stories about famous natural disasters, and a glossary.

2007-12-12

355

Evolving Requirements of the Canadian Special Operations Forces: A Future Concept Paper.  

National Technical Information Service (NTIS)

Colonel Paul Taillon's paper suggests new directions for Canadian Special Operations Forces (CANSOF), propelled mainly by the demands of the international environment since the September 11, 2001 attack in New York City. This is of special interest as Can...

J. P. Taillon

2005-01-01

356

Air Force Journal of Logistics. Special Anniversary Edition. Winter 1995. Volume 19, Number 1.  

National Technical Information Service (NTIS)

Air Force Journal of Logistics Fifteenth Anniversary: A Brief History Control of Space Debris-The Challenge of the Future - Kathleen Van Oredel; International Cooperation and Concerns in Space Logistics - Darrin Guilbeau; Sustaining Space Systems for Stra...

B. A. Newell

1995-01-01

357

Failed States and Casualty Phobia: Implications for Force Structure and Technology Choices.  

National Technical Information Service (NTIS)

The emergence of failed states as the principal source of international political instability and the appearance of mounting casualty phobia among U.S. political and military elites have significant force structure and technology implications. Overseas, i...

J. Record

2000-01-01

358

78 FR 18326 - U.S. Air Force Scientific Advisory Board; Notice of Meeting  

Federal Register 2010, 2011, 2012, 2013

...latest updates on the ongoing study outbriefs, as well as discussion of the SAB's review of Air Force Research Laboratory (AFRL) science and technology investments. The remaining FY13 Board schedule and internal restructuring options will also be...

2013-03-26

359

Armed Forces Health Surveillance Center: Global Emerging Infections Surveillance & Response System, FY 2010.  

National Technical Information Service (NTIS)

The Armed Forces Health Surveillance Center (AFHSC) was created to centralize Department of Defense (DoD) domestic and international healthcare surveillance efforts. The organization provides relevant, timely, actionable, and comprehensive health informat...

2010-01-01

360

Contractile forces driving embryonic development  

NASA Astrophysics Data System (ADS)

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.

Kaschube, Matthias

2011-03-01

361

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

PubMed Central

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

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

2008-01-01

362

Evaluation of periodontal probing forces.  

PubMed

The purpose of this study was to evaluate interexaminer and intraexaminer probing force variations in various regions of the mouth and adjacent to different tooth surfaces. Fifty-eight dental clinicians composed of 13 periodontists, 15 general dentists, 15 hygienists and 15 senior dental students probed the facial surfaces of periodontally healthy volunteers with a modified pressure-sensitive periodontal probe. The forces used during probing were calculated and analyzed by analysis of variance and t-statistics. There was wide variation in probing forces used by individuals within each clinician group. No statistical differences between the groups in mean probing force or absolute range of probing force could be detected. When pooled data were analyzed, it was found that the clinicians: (1) used probing forces ranging from 5 to 135 g, (2) probed in posterior regions with greater force than in anterior regions, and (3) probed midfacial, mesial and distal gingival units with different force. Midfacial regions were probed with the lightest force and distal regions with the heaviest force. PMID:6578320

Freed, H K; Gapper, R L; Kalkwarf, K L

1983-08-01

363

Lateral-force measurements in dynamic force microscopy  

NASA Astrophysics Data System (ADS)

Lateral forces between the tip of a force microscope and atomic-scale features on the surface of a sample can be accurately measured in a noncontact mode. Feedback-controlled excitation of the torsional eigenmode of a rectangular cantilever beam forces the tip to oscillate parallel to the surface. Forces of the order of 0.05 nN have been detected when the tip approaches a step or a sulphur impurity. The method can also be used to study the energy dissipation in the range where a tip-sample contact is formed.

Pfeiffer, O.; Bennewitz, R.; Baratoff, A.; Meyer, E.; Grütter, P.

2002-04-01

364

Trapping force and optical lifting under focused evanescent wave illumination.  

PubMed

A physical model is presented to understand and calculate trapping force exerted on a dielectric micro-particle under focused evanescent wave illumination. This model is based on our recent vectorial diffraction model by a high numerical aperture objective operating under the total internal condition. As a result, trapping force in a focused evanescent spot generated by both plane wave (TEM00) and doughnut beam (TEM*01) illumination is calculated, showing an agreement with the measured results. It is also revealed by this model that unlike optical trapping in the far-field region, optical axial trapping force in an evanescent focal spot increases linearly with the size of a trapped particle. This prediction shows that it is possible to overcome the force of gravity to lift a polystyrene particle of up to 800 nm in radius with a laser beam of power 10 microW. PMID:19484115

Ganic, Djenan; Gan, Xiaosong; Gu, Min

2004-11-01

365

Position/force control in multiple-manipulator systems  

NASA Technical Reports Server (NTRS)

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.

Wen, John T.; Murphy, Steve H.

1992-01-01

366

Force Limited Vibration Testing Monograph  

NASA Technical Reports Server (NTRS)

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.

Scharton, Terry D.

1997-01-01

367

Hydrodynamic force microscopy  

NASA Astrophysics Data System (ADS)

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.

Ulrich, Elaine Schmid

368

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...

369

Coordinated dynamic hybrid position\\/force control for multiple robot manipulators handling one constrained object  

Microsoft Academic Search

A cooperative dynamic hybrid control method for multimotion robotic mechanisms handling a single object whose motion is constrained by environment is discussed. This method takes the manipulator dynamics and object dynamics into consideration and is for controlling the motion of the object as well as for controlling the constraint force and the internal force. The following results are obtained: (1)

Tsuneo Yoshikawa; Xinzhi Zheng

1990-01-01

370

Chemical-Biological Attack: Achilles Heel of the Air Expeditionary Force.  

National Technical Information Service (NTIS)

The U.S. National Security Strategy calls for our armed forces to help shape the international environment, respond to threats and crises, and prepare now for an uncertain future. To assist in the execution of this strategy, the U.S. Air Force is developi...

B. C. Hepburn

1999-01-01

371

Collision forces for compliant projectiles  

NASA Technical Reports Server (NTRS)

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.

Grady, Joseph E.

1990-01-01

372

Forced circumcision of men (abridged).  

PubMed

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

Glass, Michael

2014-08-01

373

Medium-modified Casimir forces  

NASA Astrophysics Data System (ADS)

We argue that the results for the vacuum forces on a slab and on an atom embedded in a magnetodielectric medium near a mirror, obtained using a recently suggested Lorentz-force approach to the Casimir effect, are equivalent to the corresponding results obtained in a traditional way. We also derive a general expression for the atom-atom force in a medium and extend a few classical results concerning this force in vacuum and dielectrics to magnetodielectric systems. This, for example, reveals that the (repulsive) interaction between atoms of different polarizability type is at small distances unaffected by a (weakly polarizable) medium.

Tomas, M. S.

2006-05-01

374

Knudsen force based MEMS structures  

NASA Astrophysics Data System (ADS)

Knudsen forces are gas molecular forces which originate from the differential temperatures in rarefied gases. We report measurements of these forces at normal ambience on test structures made by surface micromachining of polysilicon. Using these results, a surface micromachined Knudsen vacuum sensor has been simulated, fabricated and characterized. The vacuum sensor has an area of 1 mm2. The fabricated device has a sensitivity of 40 fF Pa?1 in the pressure range of 0.1–10 Pa. The measured data is analysed and the magnitude of the Knudsen's force is extracted. The paper also suggests ways to enhance the range and improve the sensitivity of such sensors.

Vikrant Sista, Shanmukha; Bhattacharya, Enakshi

2014-04-01

375

Spring-force measuring device  

SciTech Connect

A device is described for measuring the spring-force of resilient spacer projections set into spacer grids of nuclear reactor fuel assemblies to push fuel rods surrounded by spacer meshes against at least two oppositely disposed rigid spacer projections. It includes a force measuring plug having a diameter equal to the diameter of a fuel rod to be fixed in the spacer grid, and a flexible beam integral with the force measuring plug. The flexible beam has a free end in contact with a first resilient spacer projection to be measured, and another end firmly connected to the force measuring plug and has at least one wire strain gage disposed thereon.

Bezold, H.; Steven, J.

1981-01-27

376

Climate forcing by stratospheric aerosols  

NASA Technical Reports Server (NTRS)

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.

Lacis, Andrew; Hansen, James; Sato, Makiko

1992-01-01

377

Climate forcing by stratospheric aerosols  

NASA Astrophysics Data System (ADS)

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.

Lacis, Andrew; Hansen, James; Sato, Makiko

1992-08-01

378

Tunneling magnetic force microscopy  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

379

Experimental characterization of jet static forces impacting waste tank components  

SciTech Connect

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.

Bamberger, J.A.; Bates, J.M. (Pacific Northwest Lab., Richland, WA (USA)); Waters, E.D. (Westinghouse Hanford Co., Richland, WA (USA))

1990-06-01

380

Community College Internal Auditors: Internal Audit Guidebook.  

ERIC Educational Resources Information Center

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…

Jones, Ronna; And Others

381

Risk assessment in international operations  

SciTech Connect

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.

Stricklin, Daniela L. [FOI, Swedish Defence Research Agency, CBRN Security and Defence, Umea, SE-90182 (Sweden)], E-mail: daniela.stricklin@foi.se

2008-11-15

382

Characterization of atomic force microscope tips by adhesion force measurements  

SciTech Connect

The resolution limit in an atomic force microscope image usually is attributed to the finite radius of the contacting probe. Here, it is shown that this assumption is valid only when adhesion forces are minimal. Relative to the tip-imposed geometrical limit, the resolution and contrast in AFM images can be degraded by increasing adhesion forces. The large adhesion forces observed for some tips at low humidity conditions are shown to be due to tip contamination or poorly formed tip apexes. Methods to determine and to reduce the extent of tip contamination are described. Cleaning carried out using UV-ozone or oxygen-plasma etching were found to significantly reduce the minimum adhesion force.

Thundat, T.; Zheng, X.; Chen, G.Y.; Sharp, S.L.; Warmack, R.J. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6123 (United States)); Schowalter, L.J. (Center for Integrated Electronics and Department of Physics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States))

1993-10-11

383

Relationship between adhesion and friction forces  

Microsoft Academic Search

The Surface Forces Apparatus technique was used to measure the normal (perpendicular) and lateral forces between variously prepared surfaces under both dry and lubricated conditions. 'Normal' forces include the force vs distance functions, F(D), for surfaces separated by thin liquid films as well as the adhesion forces and energies, ?, for two surfaces in adhesional contact. 'Lateral' forces include the

Jacob N. Israelachvili; You-Lung Chen; Hisae Yoshizawa

1994-01-01

384

Wave Loading on Floating Platforms by Internal Solitary Waves  

Microsoft Academic Search

Morison's equation is used for estimating internal solitary wave-induced forces exerted on SPAR and semi-submersible platforms. And the results we got have also been compared to ocean surface wave loading. It is shown that Morison's equation is an appropriate approach to estimate internal wave loading even for SPAR and semi-submersible platforms, and the internal solitary wave load on floating platforms

H. Q. Zhang; J. C. Li

2009-01-01

385

The International Baccalaureate  

ERIC Educational Resources Information Center

The quest for a satisfactory university entrance examination continues. This article explains the growing body of opinion favoring adoption of the International Baccalaureate, because of the growth of international schools and international business.

Peterson, A. D. C.

1971-01-01

386

Cancer from internal emitters.  

National Technical Information Service (NTIS)

Irradiation from internal emitters, or internally deposited radionuclides, is an important component of radiation exposures encountered in the workplace, home, or general environment. Long-term studies of human populations exposed to various internal emit...

B. B. Boecker W. C. Griffith

1995-01-01

387

Radiative forcing and climate response  

NASA Astrophysics Data System (ADS)

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.

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

1997-03-01

388

Simple and Scalable Force Actuator.  

National Technical Information Service (NTIS)

One problem posed by robots that must perform in unstructured environments and interact with humans is that of achieving high fidelity force control as well as compliance in a compact form factor. Force control, as opposed to only position control, allows...

E. Torres-Jara J. Banks

2005-01-01

389

Jaw bite force measurement device.  

PubMed

We describe a cost-effective device that uses an off-the-shelf force transducer to measure patient bite force as a diagnostic aid in determining dental implant size, number of implants, and prosthetic design for restoring partial edentulism. The main advantages of the device are its accuracy, simplicity, modularity, ease of manufacturing, and low cost. PMID:20822470

Flanagan, Dennis; Ilies, Horea; O'Brien, Brendan; McManus, Anne; Larrow, Beau

2012-08-01

390

The Forced Hard Spring Equation  

ERIC Educational Resources Information Center

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…

Fay, Temple H.

2006-01-01

391

Climate forcing by stratospheric aerosols  

Microsoft Academic Search

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 2mum, the global average greenhouse effect of the aerosols exceeds the albedo effect, causing a

Andrew Lacis; James Hansen; Makiko Sato

1992-01-01

392

Armed Forces Expeditionary Service Medal.  

National Technical Information Service (NTIS)

The front of the armed forces expeditionary service medal features a star upon which is superimposed an eagle with spread wings perched on a sheathed sword. ARMED FORCES EXPEDITIONARY SERVICE is inscribed on the front of the medal. The rear of the medal c...

J. C. Morris

1965-01-01

393

Coriolis Force and Noninertial Effects  

NSDL National Science Digital Library

This site, from Oregon State University, offers animations that illustrate fictitious forces on frictionless objects on the Earth's surface. The graphic display contrasts the path of the object as seen from space and as seen from Earth's surface. The effects of both the centrifugal and Coriolis forces are shown.

Mcintyre, David

2007-11-29

394

DNA: A Programmable Force Sensor  

Microsoft Academic Search

Direct quantification of biomolecular interaction by single-molecule force spectroscopy has evolved into a powerful tool for materials and life sciences. We introduce an approach in which the unbinding forces required to break intermolecular bonds are measured in a differential format by comparison with a known reference bond (here, a short DNA duplex). In addition to a marked increase in sensitivity

Christian Albrecht; Kerstin Blank; Mio Lalic-Mülthaler; Siegfried Hirler; Thao Mai; Ilka Gilbert; Susanne Schiffmann; Tom Bayer; Hauke Clausen-Schaumann; Hermann E. Gaub

2003-01-01

395

Simplified Relativistic Force Transformation Equation.  

ERIC Educational Resources Information Center

A simplified relativistic force transformation equation is derived and then used to obtain the equation for the electromagnetic forces on a charged particle, calculate the electromagnetic fields due to a point charge with constant velocity, transform electromagnetic fields in general, derive the Biot-Savart law, and relate it to Coulomb's law.…

Stewart, Benjamin U.

1979-01-01

396

Retention in the Canadian Forces.  

National Technical Information Service (NTIS)

Approximately half the personnel in the Canadian Forces (CF) will have 20 years or more of service and be eligible to retire within the next three to five years. Force expansion, high operational and personnel tempo, family instability and high risk deplo...

J. D. Vass

2007-01-01

397

Grasp force control in telemanipulation  

NASA Technical Reports Server (NTRS)

This paper presents two experiments which focus upon the issue of grasp force control in telemanipulation. The first experiment examines the ability to control and stabilize master-controller grasp force during a 30-s compensatory tracking task under different levels of master controller digit mass, friction, and backlash. The second experiment explores the potential for substituting tactile feedback in lieu of direct force-feedback to gage and control remote grasp force. Results show that subjects were better able to control force when mass and friction levels were increased. Even when perceptual gains between tactile and direct force feedback displays were matched, force reflection produced better grasp control. The lack of backlash effects and improvements in performance with direct force reflection in comparison to tactile feedback are attributable to reflexive short-loop adjustment of grasp tension afforded by the muscle's length-tension control system. The criterion of acceptable operator performance, dependent upon both the quality of the transmission of control commands and feedback, and the response of the remote device, is discussed.

Wiker, Steven F.; Duffie, Neil A.

1992-01-01

398

Radiative forcing and climate response  

Microsoft Academic Search

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

J. Hansen; M. Sato; R. Ruedy

1997-01-01

399

Climate Forcing by Anthropogenic Aerosols  

Microsoft Academic Search

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

R. J. Charlson; S. E. Schwartz; J. M. Hales; R. D. Cess; J. A. Coakley Jr.; J. E. Hansen; D. J. Hofmann

1992-01-01

400

Climate forcing by stratospheric aerosols  

Microsoft Academic Search

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

Andrew Lacis; James Hansen; Makiko Sato

1992-01-01

401

Short Time Force Measurement System.  

National Technical Information Service (NTIS)

The development of the SFS (Short time Force and moment measurement System) is considered. It enables measurement of aerodynamic forces and moments at testing times of less than 10 ms. This is required for measurements in high enthalpy shock tunnels to si...

J. Mertens K. Koenig

1991-01-01

402

International Technology Exchange Division: 1993 Annual report  

SciTech Connect

The Office of Technology Development (OTD) was established to ensure that reliable and acceptable technologies are available for implementation at DOE sites and that a technically trained work force is available to complete the EM mission by 2019. OTD established the International Technology Exchange Staff (ITES) to identify, evaluate, and acquire international technologies which can accelerate US DOE cleanup operations. ITES`s goal is to pursue international collaboration among government organizations, educational institutions, and private industry to identify world-wide needs and available technologies that will meet US environmental needs in general, and EM cleanup needs in particular; and establish mechanisms by which US government ER/WM technologies will be transferred to the US private sector for commercialization and export to international markets. ITES has developed the following strategic objectives to implement its international goals: develop and implement EM`s policy for international programs in accordance with DOE and US Government policies and regulations; establish efficient and predictable international technology transfer mechanisms; assist the US private sector in the commercialization and deployment of federally funded EM technologies and related knowledge in international markets; leverage US and non-US resources to accelerate international development and regulatory acceptance of EM technologies; contribute to the improvement of EM`s training of US students, scientists, and managers on international environmental issues. A summary and descriptions of program activities and accomplishments are given for 17 programs which comprise the four main areas of the ITES program: Activities with the Former Soviet Union, International Technology Transfer, International Cooperation, and Information Systems and Publications. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Not Available

1993-12-31

403

Gene regulation by mechanical forces  

NASA Technical Reports Server (NTRS)

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.

Oluwole, B. O.; Du, W.; Mills, I.; Sumpio, B. E.

1997-01-01

404

Note: Helical nanobelt force sensors  

NASA Astrophysics Data System (ADS)

We present the fabrication and characterization of helical nanobelt force sensors. These self-sensing force sensors are based on the giant piezoresistivity of helical nanobelts. The three-dimensional helical nanobelts are self-formed from 27 nm-thick n-type InGaAs/GaAs bilayers using rolled-up techniques, and assembled onto electrodes on a micropipette using nanorobotic manipulations. The helical nanobelt force sensors can be calibrated using a calibrated atomic force microscope cantilever system under scanning electron microscope. Thanks to their giant piezoresistance coefficient (515 × 10-10 Pa-1), low stiffness (0.03125 N/m), large-displacement capability (~10 ?m), and good fatigue resistance, they are well suited to function as stand-alone, compact (~20 ?m without the plug-in support), light (~5 g including the plug-in support), versatile and large range (~?N) and high resolution (~nN) force sensors.

Hwang, G.; Hashimoto, H.

2012-12-01

405

Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse  

NASA Astrophysics Data System (ADS)

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.

Bond, T. C.; Zarzycki, C.; Flanner, M. G.; Koch, D. M.

2010-06-01

406

Visualization of Force Fields in Protein StructurePrediction  

SciTech Connect

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.

Crawford, Clark; Kreylos, Oliver; Hamann, Bernd; Crivelli, Silvia

2005-04-26

407

Energy release and plasma heating by forced magnetic reconnection  

NASA Astrophysics Data System (ADS)

A simple model of forced magnetic reconnection in a force-free magnetic field is considered, which allows the calculation of the magnetic energy release during the current sheet reconnection. The dependence of this energy on characteristics of the magnetic configuration has been studied, and it was found that the released energy becomes very large when the field is near the marginal tearing stability. A persistent plasma heating provided by ongoing external driving and internal reconnection is most efficient when the time-scales of these processes are comparable. Possible implications of the obtained results for the problem of solar coronal heating are briefly discussed.

Vekstein, G. E.; Jain, Rekha

1998-05-01

408

How Predictive Is Grip Force Control in the Complete Absence of Somatosensory Feedback?  

ERIC Educational Resources Information Center

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…

Nowak, Dennis A.; Glasauer, Stefan; Hermsdorfer, Joachim

2004-01-01

409

Are Mathematics and Science Test Scores Good Indicators of Labor-Force Quality?  

ERIC Educational Resources Information Center

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…

Chen, Shiu-Sheng; Luoh, Ming-Ching

2010-01-01

410

Rolling Contact Force Energy Reconstruction  

NASA Astrophysics Data System (ADS)

Knowledge of the forces at the wheel-rail contact is fundamental to estimate the consequences in terms of noise and vibration. The traditional use of strain gauges mounted on the wheel web and axle is not capable of determining the high-frequency content of the contact force. Measurements made on the rail are characterized by the spatial variability of input-output transfer functions which makes it difficult to estimate the contact force by simple inversion of the point frequency response function. In this study the problem of rolling contact force reconstruction has been approached through the following steps: (i) the track has been characterized precisely for a finite length by the analysis of the time series of several impacts supplied with an instrumented hammer by using an ARMAX model that proved to be capable of modelling the vertical dynamics of the rail up to 5 kHz; (ii) the response of the rail has been simulated with a random force acting on the system, and the variability of the transfer function has been taken into account by distributing the force on adjacent elements; (iii) the simulated response has been compared with the rail acceleration measured for the passage of several trains; (iv) the wheel-rail contact force has been estimated with a closed-loop algorithm. It has thus been possible to reconstruct the13octave power spectrum of contact forces with a simple and stable iterative procedure. Forces reconstructed from different sensors were found to be practically the same for a given wheel; forces from nominally similar wheels are statistically examined and partial results of comparisons made on different rolling stock are shown.

BRACCIALI, A.; CASCINI, G.

2000-09-01

411

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

PubMed Central

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.

Kshirsagar, Rajesh; Jaggi, Nitin; Halli, Rajshekhar

2011-01-01

412

Electrostatic Force in Blowing Snow  

NASA Astrophysics Data System (ADS)

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.

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

413

Climate Forcing by Anthropogenic Aerosols  

NASA Astrophysics Data System (ADS)

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.

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

414

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

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…

General Accounting Office, Washington, DC. National Security and International Affairs Div.

415

[International Education Programs].  

ERIC Educational Resources Information Center

Perspectives concerning the overall process of providing international education are considered in three articles. In "The Development of an International Commitment: A Case Study," Earl L. Backman describes the successful implementation of an international program at the University of North Carolina, Charlotte. The Program for International

Slavin, Gerald M., Ed.; Colahan, Clark A., Ed.

1981-01-01

416

Measuring internal customer satisfaction  

Microsoft Academic Search

Identifies two empirically derived measures of internal customer support used to assess team effectiveness from the perspective of the team’s internal customers. The measures, personal service and technical competence, are based on analysis of the responses of 465 individuals representing 150 internal customer teams. When compared, the expected (self) ratings of the members of internal intact work teams were more

G. Ronald Gilbert

2000-01-01

417

Analysis of hystereses in force length and force calcium relations.  

PubMed

Analysis of the hystereses in the force-length relationship at constant Ca(2+) concentration and in the force-calcium relationship at constant sarcomere length (SL) provides insight into the mechanisms that control cross-bridge (XB) recruitment. The hystereses are related here to two mechanisms that regulate the number of strong XBs: the cooperativity, whereby the number of strong XBs determines calcium affinity, and the mechanical feedback, whereby the shortening velocity determines the duration for which the XBs are in the strong state. The study simulates the phenomena and defines the role of these feedbacks. The model that couples calcium kinetics with XB cycling was built on Simulink software (Matlab). Counterclockwise (CCW) hysteresis, wherein the force response lags behind the SL oscillations, at a constant calcium level, is obtained in the force-length plane when neglecting the mechanical feedback and accounting only for the cooperativity mechanism. Conversely, the force response precedes the SL oscillations, yielding a clockwise (CW) hysteresis when only the mechanical feedback is allowed to exist. In agreement with experimental observations, either CW or CCW hysteresis is obtained when both feedbacks coexist: CCW hystereses are obtained at low frequencies (<3 Hz), and the direction is reversed to CW at higher frequencies (>3 Hz). The cooperativity dominates at low frequencies and allows the muscle to adapt XB recruitment to slow changes in the loading conditions. The changeover frequency from CCW to CW hysteresis defines the velocity limit above which the muscle absorbs rather than generates energy. The hysteresis in the force-calcium relation is conveniently explained by the same cooperativity mechanism. We propose that a single cooperativity mechanism that depends on the number of strong XBs can explain the hystereses in the force-length as well as in the force-calcium relationships. PMID:15598871

Yaniv, Yael; Sivan, Raphael; Landesberg, Amir

2005-01-01

418

The force of impacting rain.  

PubMed

Drop impacts are difficult to characterize due to their transient, non-stationary nature. We discuss the force generated during such impacts, a key quantity for animals, plants, roofs or soil erosion. Although a millimetric drop has a modest weight, it can generate collision forces on the order of thousand times this weight. We measure and discuss this amplification, considering natural parameters such as drop radius and density, impact speed and response time of the substrate. We finally imagine two kinds of devices allowing us to deduce the size of the raindrop from impact forces. PMID:24879634

Soto, Dan; De Larivière, Aurélie Borel; Boutillon, Xavier; Clanet, Christophe; Quéré, David

2014-07-21

419

Forces on the Human Molecule  

NSDL National Science Digital Library

In this physical activity, two lines of learners link hands and arms to model a beam subject to various loading schemes. They discover how inter-atomic forces react to the five fundamental load types that can act on structures: tension, compression, shear, bending, and torsion. This activity can be used as an introduction to these forces or as review. Note: The description refers to learners as "molecules of steel" and their arms being the bonds between them. Since steel is an alloy of multiple elements, each learner would represent an atom and their arms are the inter-atomic forces which join them.

Institute, Worcester P.

2005-01-01

420

Relative microelastic mapping of living cells by atomic force microscopy.  

PubMed

The spatial and temporal changes of the mechanical properties of living cells reflect complex underlying physiological processes. Following these changes should provide valuable insight into the biological importance of cellular mechanics and their regulation. The tip of an atomic force microscope (AFM) can be used to indent soft samples, and the force versus indentation measurement provides information about the local viscoelasticity. By collecting force-distance curves on a time scale where viscous contributions are small, the forces measured are dominated by the elastic properties of the sample. We have developed an experimental approach, using atomic force microscopy, called force integration to equal limits (FIEL) mapping, to produce robust, internally quantitative maps of relative elasticity. FIEL mapping has the advantage of essentially being independent of the tip-sample contact point and the cantilever spring constant. FIEL maps of living Madine-Darby canine kidney (MDCK) cells show that elasticity is uncoupled from topography and reveal a number of unexpected features. These results present a mode of high-resolution visualization in which the contrast is based on the mechanical properties of the sample. PMID:9512052

A-Hassan, E; Heinz, W F; Antonik, M D; D'Costa, N P; Nageswaran, S; Schoenenberger, C A; Hoh, J H

1998-03-01

421

Experimental Investigation of Forces Produced by Misaligned Steel Rollers  

NASA Technical Reports Server (NTRS)

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.

Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

2010-01-01

422

Experimental Investigation of Forces Produced by Misaligned Steel Rollers  

NASA Technical Reports Server (NTRS)

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.

Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

2010-01-01

423

Motion and force control of multiple robotic manipulators  

NASA Technical Reports Server (NTRS)

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.

Wen, John T.; Kreutz-Delgado, Kenneth

1992-01-01

424

Non-contact Stiffness Sensing by Considering the Change of Fluid Force due to Object Deformation  

NASA Astrophysics Data System (ADS)

Non-contact stiffness sensor is often utilized especially for medical fields due to its advantage of avoiding damage to tissues and keeping sanitary. However, it is hard to measure the force accurately, because the fluid jet based force much depends upon the shape after deformation of object. This paper proposes an innovative approach where the external force is adaptively calibrated based on the deformation of object so that we can evaluate the internal stiffness parameters more accurately than that of conventional approaches. It is shown that the proposed method can improve the accuracy of force application with even 100% at an extreme case.

Tanaka, Nobuyuki; Higashimori, Mitsuru; Kaneko, Makoto

425

The new science of sales force productivity.  

PubMed

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

Ledingham, Dianne; Kovac, Mark; Simon, Heidi Locke

2006-09-01

426

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

SciTech Connect

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.

Xie Hui; Vitard, Julien; Haliyo, Sinan; Regnier, Stephane [Institut des Systemes Intelligents et Robotique (ISIR), Universite Pierre et Marie Curie-Paris 6/CNRS, 18 Route du Panorama-BP 61, 92265 Fontenay-Aux-Roses (France); Boukallel, Mehdi [Laboratoire de Robotique et Mesorobotique (LRM), CEA, 18 Route du Panorama-BP 61, 92265 Fontenay-Aux-Roses (France)

2008-03-15

427

Mental Health Task Force Report.  

National Technical Information Service (NTIS)

Recommendations of a task force charged with examining conditions of mental health operatios in western Massachusetts are contained in this report. The greatest needs in the region were found to be crisis intervention, childrens' services, community-parti...

D. A. Allen

1974-01-01

428

Teleoperation with virtual force feedback  

SciTech Connect

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.

Anderson, R.J.

1993-08-01

429

Dissipative Forces and Quantum Mechanics  

ERIC Educational Resources Information Center

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)

Eck, John S.; Thompson, W. J.

1977-01-01

430

Atomic force microscope: Enhanced sensitivity.  

National Technical Information Service (NTIS)

Atomic force microscopes (AFMs) are a recent development representing the state of the art in measuring ultrafine surface features. Applications are found in such fields of research as biology, microfabrication, material studies, and surface chemistry. Fi...

D. T. Davis

1995-01-01

431

Restoring force method and response estimation  

SciTech Connect

The restoring force method is briefly outlined. Signal modifications that are necessary to successfully determine restoring force functions are discussed and illustrated. Restoring force functions for a base and a force excited system were determined and their effectiveness demonstrated by comparing measured and predicted signals. Additional developments that would make the restoring force method more general are suggested. 5 refs., 12 figs.

Endebrock, E.G.

1989-01-01

432

A tense situation: forcing tumour progression  

Microsoft Academic Search

Cells within tissues are continuously exposed to physical forces including hydrostatic pressure, shear stress, and compression and tension forces. Cells dynamically adapt to force by modifying their behaviour and remodelling their microenvironment. They also sense these forces through mechanoreceptors and respond by exerting reciprocal actomyosin- and cytoskeletal-dependent cell-generated force by a process termed 'mechanoreciprocity'. Loss of mechanoreciprocity has been shown

Darci T. Butcher; Tamara Alliston; Valerie M. Weaver

2009-01-01

433

Resonant Forcing of Chaotic Dynamics  

Microsoft Academic Search

We study resonances of multidimensional chaotic map dynamics. We use the calculus of variations to determine the additive\\u000a forcing function that induces the largest response, that is, the greatest deviation from the unperturbed dynamics. We include\\u000a the additional constraint that only select degrees of freedom be forced, corresponding to a very general class of problems\\u000a in which not all of

Vadas Gintautas; Glenn Foster; Alfred W. Hübler

2008-01-01

434

Electrostatic forces for personnel restraints  

NASA Technical Reports Server (NTRS)

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.

Ashby, N.; Ciciora, J.; Gardner, R.; Porter, K.

1977-01-01

435

Electrostatic force on saltating sand  

NASA Astrophysics Data System (ADS)

In blizzards and sandstorms, wind transport of particles is associated with separation of electrostatic charge. Moving particles develop charge of sign opposite the electrostatic charge on stationary surface particles. This electrification produces forces in addition to the gravitational and fluid friction forces that determine trajectories for particles being transported in saltation. Evaluating electrostatic forces requires the electric field strength very near the saltation surface and charge-to-mass ratios for the moving particles. In a low-level blowing sand event we measured an average charge-to-mass ratio of +60 ?C kg-1 on the saltating particles at 5-cm height and a maximum electric field of +166 kV m-1 at 1.7-cm height, in wind gusts near 12 m s-1 at 1.5-m height. The electrostatic force estimated from these measurements was equal in magnitude to the gravitational force on the saltating particles. Including electrostatic forces in the equations of motion for saltating particles may help explain discrepancies between measurements and models of saltation transport.

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

1998-04-01

436

Forces Applied by Cilia Measured on Explants from Mucociliary Tissue  

PubMed Central

Forces applied by intact mucus-propelling cilia were measured for the first time that we know of using a combined atomic force microscopy (AFM) and electrooptic system. The AFM probe was dipped into a field of beating cilia and its time-dependent deflection was recorded as it was struck by the cilia while the electrooptic system simultaneously and colocally measured the frequency to ensure that no perturbation was induced by the AFM probe. Using cilia from frog esophagus, we measured forces of ?0.21 nN per cilium during the effective stroke. This value, together with the known internal structure of these cilia, leads to the conclusion that most dynein arms along the length of the axoneme contribute to the effective stroke of these cilia.

Teff, Zvi; Priel, Zvi; Gheber, Levi A.

2007-01-01

437

Drag force scaling for penetration into granular media.  

PubMed

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

Katsuragi, Hiroaki; Durian, Douglas J

2013-05-01

438

Fluid of Janus molecules between two walls: The solvation force  

NASA Astrophysics Data System (ADS)

We apply a density functional theory to calculate the solvation force in the system involving Janus particles confined between two planar walls. Janus particles are modeled as spheres composed of attractive and repulsive parts and their orientation is described by the vectors representing internal degrees of freedom. We consider the cases of pores with identical walls, as well as the pores with competing walls (the so-called Janus-like pores). The density functional approach we employ combines fundamental measure theory with a mean-field approximation for the anisotropic interparticle interaction. We study how the solvation force and the orientational structure of confined particles depend on the competition between the surface field and the interactions between confined molecules and on the parameters of the model such as temperature and density. It is shown that the anisotropic interaction between the confined molecules and the character of the walls significantly influence the solvation force.

Patrykiejew, A.; Soko?owski, S.; Soko?owska, Z.; Ilnytskyi, Ja.

2013-12-01

439

PBS Learning Media: Teaching from Space - Centripetal Force  

NSDL National Science Digital Library

This unique five-minute video features a NASA astronaut demonstrating centripetal force in ways students cannot observe in daily life. The video was shot in a weightless environment -- on board the International Space Station. The astronaut swings a tethered tool around a cord, rotates a bag of tea to show how air bubbles are pushed to the center, and spins a water droplet to show deformation resulting from centripetal force. The video was designed to promote understanding of the force that keeps planets in their orbits and keeps humans in their seats on a looping roller coaster. The video itself was developed by the NASA Teaching from Space program, and packaged to include background information and discussion questions. PBS Learning Media is a growing collection of videos, lessons, and activities assembled by researchers, scientists, and experienced teachers to promote the use of digital resources in the classroom.

2012-11-19

440

International Business Education in an International City  

Microsoft Academic Search

Internationalizing the business administration curriculum has been an ongoing concern for educators. The experience in the United States appears to have encountered certain hurdles and international business education has not yet gone into full swing. On the other hand, for those countries which depend heavily on international business, the subject is generally regarded as important. Four different groups of students

Kin-chok Mun; Kitty Young; H. F. Lau; T. W. C. Lo

1991-01-01

441

Effect of foot orthoses on magnitude and timing of rearfoot and tibial motions, ground reaction force and knee moment during running  

Microsoft Academic Search

Changes in magnitude and timing of rearfoot eversion and tibial internal rotation by foot orthoses and their contributions to vertical ground reaction force and knee joint moments are not well understood. The objectives of this study were to test if orthoses modify the magnitude and time to peak rearfoot eversion, tibial internal rotation, active ground reaction force and knee adduction

Mansour Eslami; Mickaël Begon; Sébastien Hinse; Heydar Sadeghi; Peter Popov; Paul Allard

2009-01-01

442

Role of Individual Basal Ganglia Nuclei in Force Amplitude Generation  

PubMed Central

The basal ganglia-thalamo-cortical loop is an important neural circuit that regulates motor control. A key parameter that the nervous system regulates is the level of force to exert against an object during tasks such as grasping. Previous studies indicate that the basal ganglia do not exhibit increased activity with increasing amplitude of force, although these conclusions are based mainly on the putamen. The present study used functional magnetic resonance imaging to investigate which regions in the basal ganglia, thalamus, and motor cortex display increased activity when producing pinch-grip contractions of increasing force amplitude. We found that the internal portion of the globus pallidus (GPi) and subthalamic nucleus (STN) had a positive increase in percent signal change with increasing force, whereas the external portion of the globus pallidus, anterior putamen, posterior putamen, and caudate did not. In the thalamus we found that the ventral thalamic regions increase in percent signal change and activation volume with increasing force amplitude. The contralateral and ipsilateral primary motor/somatosensory (M1/S1) cortices had a positive increase in percent signal change and activation volume with increasing force amplitude, and the contralateral M1/S1 had a greater increase in percent signal change and activation volume than the ipsilateral side. We also found that deactivation did not change across force in the motor cortex and basal ganglia, but that the ipsilateral M1/S1 had greater deactivation than the contralateral M1/S1. Our findings provide direct evidence that GPi and STN regulate the amplitude of force output. These findings emphasize the heterogeneous role of individual nuclei of the basal ganglia in regulating specific parameters of motor output.

Spraker, Matthew B.; Yu, Hong; Corcos, Daniel M.; Vaillancourt, David E.

2008-01-01

443

Fluorescence-force spectroscopy at the single molecule level  

NASA Astrophysics Data System (ADS)

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.

Zhou, Ruobo

444

Global modelling of surface and internal tides  

NASA Astrophysics Data System (ADS)

Almost 250 years ago Laplace formulated a system of hydrodynamical equations that can describe the dynamics of ocean tides given astronomical forcing and global topography. But these equations lack dissipation that is required to cause the observed slowdown of Earth's rotation. During the last 100 years the importance of two dissipative processes has been recognised: energy loss to a turbulent bottom boundary layer in shallow seas and, more recently, energy conversion from surface to internal tides (i.e. internal waves at tidal frequency). And this internal tide is now thought to play an important role in setting the global oceanic circulation, and, therefore, climate on Earth. Here, a new global numerical model of ocean tides is described. Special emphasis is placed upon accounting for the energy loss to internal tides in a simplified but physically consistent way, which is achieved via explicit modelling of linear internal wave generation at specified tidal frequencies. The model resolution is sufficiently high to resolve a few low-mode internal tides which capture the majority of barotropic-to-baroclinic energy conversion. The advantages (and limitations) of this approach are examined, by comparison with the model results obtained with popular internal wave drag parametrization schemes. Although our purely dynamical model is less accurate than data-constrained models, it is more flexible and can be used to explore tidal regimes of the past and future and their climatological implications.

Lapin, Vladimir; Griffiths, Stephen

2014-05-01

445

Training program to prepare the U.S. DOE laboratories for the entry into force of the protocol additional to the agreement between the United States of America and the International Atomic Energy Agency for the application of safeguards in the United  

Microsoft Academic Search

In 2008, a joint team from Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL) consisting of specialists in training IAEA inspectors in the use of complementary access activities formulated a training program to prepare the U.S DOE laboratories for the entry into force of the U.S. Additional Protocol. Since the U.S. Additional Protocol would allow for IAEA access

Brian David Boyer; Rebecca C Stevens; Eva C Uribe; M Analisa Sandoval; John N Valente; John U Valente; Jae H Jo; Joana Sellen; Edward Wonder

2009-01-01

446

Sustainability and International Standards  

NSDL National Science Digital Library

This paper describes the need for courses that link standards and sustainability and reviews an Oklahoma State University Environmental Science graduate course in Sustainability and International Standards. The course conveys the importance of voluntary international standards, such as from ASTM International or the International Organization for Standardization (ISO), to sustainability. The curriculum uses an innovative experiential learning approach whereby students research and develop a standard using the ASTM International process. One driven student joined ASTM International and worked to see her class project catalyze the publication of ASTM E 2348 Guide for Framework for a Consensus-Based Environmental Decision-Making Process.

Reisdorph, David

2009-08-28

447

Air Force Recruitment: A Geographic Perspective.  

National Technical Information Service (NTIS)

Beginning in 1973 the Armed Forces implemented an All Volunteer Force recruitment policy. Since then, the Armed Forces have relied heavily upon propensity studies in order to make recruitment policy decisions. By aligning with the adage 'the best predicto...

J. J. Ross

2000-01-01

448

Making the Future Total Force Work.  

National Technical Information Service (NTIS)

The Air Force is implementing Future Total Force (FTF) as one method of transformation. Through FTF the Air Force will better meet the challenges of a shrinking budget aging aircraft fleet and emerging missions by integrating (or associating) different co...

S. G. Buckman

2006-01-01

449

USAF Force Protection: Do We Really Care.  

National Technical Information Service (NTIS)

The US Air Force provides the preponderance of the world's most lethal, technologically superior airpower, yet does comparatively little to protect it when its most vulnerable on the ground. Although the Air Force concept of force projection requires depl...

W. P. Delaney

1998-01-01

450

Canadian Forces Addictions Awareness and Prevention Strategy.  

National Technical Information Service (NTIS)

In 2002, as part of the restructuring to improve health care delivery in the Canadian Forces (CF), the health promotion program, Strengthening the Forces (STF), was enhanced within the CF Health Services Directorate of Force Health Protection (DFHP) which...

D. Brothers D. Chafe

2011-01-01

451

Atomic Forces for Geometry-Dependent Point Multipole and Gaussian Multipole Models  

PubMed Central

In standard treatments of atomic multipole models, interaction energies, total molecular forces, and total molecular torques are given for multipolar interactions between rigid molecules. However, if the molecules are assumed to be flexible, two additional multipolar atomic forces arise due to 1) the transfer of torque between neighboring atoms, and 2) the dependence of multipole moment on internal geometry (bond lengths, bond angles, etc.) for geometry-dependent multipole models. In the current study, atomic force expressions for geometry-dependent multipoles are presented for use in simulations of flexible molecules. The atomic forces are derived by first proposing a new general expression for Wigner function derivatives ?Dlm?m/??. The force equations can be applied to electrostatic models based on atomic point multipoles or Gaussian multipole charge density. Hydrogen bonded dimers are used to test the inter-molecular electrostatic energies and atomic forces calculated by geometry-dependent multipoles fit to the ab initio electrostatic potential (ESP). The electrostatic energies and forces are compared to their