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1

Internal forces during object manipulation  

PubMed Central

Internal force is a set of contact forces that does not disturb object equilibrium. The elements of the internal force vector cancel each other and, hence, do not contribute to the resultant (manipulation) force acting on the object. The mathematical independence of the internal and manipulation forces allows for their independent (decoupled) control realized in robotic manipulators. To examine whether in humans internal force is coupled with the manipulation force and what grasping strategy the performers utilize, the subjects (n=6) were instructed to make cyclic arm movements with a customized handle. Six combinations of handle orientation and movement direction were tested. These involved: parallel manipulations (1) VV task (vertical orientation and vertical movement) and (2) HH task (horizontal orientation and horizontal movement); orthogonal manipulations (3) VH task (vertical orientation and horizontal movement) and (4) HV task (horizontal orientation and vertical movement); and diagonal manipulations (5) DV task (diagonal orientation and vertical movement) and (6) DH task (diagonal orientation and horizontal movement). Handle weight (from 3.8 to 13.8 N), and movement frequency (from 1 to 3 Hz) were systematically changed. The analysis was performed at the thumb-virtual finger level (VF, an imaginary finger that produces a wrench equal to the sum of wrenches produced by all the fingers). At this level, the forces of interest could be reduced to the internal force and internal moment. During the parallel manipulations, the internal (grip) force was coupled with the manipulation force (producing object acceleration) and the thumb-VF forces increased or decreased in phase: the thumb and VF worked in synchrony to grasp the object more strongly or more weakly. During the orthogonal manipulations, the thumb-VF forces changed out of phase: the plots of the internal force vs. object acceleration resembled an inverted letter V. The HV task was the only task where the relative phase (coupling) between the normal forces of the thumb and VF depended on oscillation frequency. During the diagonal manipulations, the coupling was different in the DV and DH tasks. A novel observation of substantial internal moments is described: the moments produced by the normal finger forces were counterbalanced by the moments produced by the tangential forces such that the resultant moments were close to zero. Implications of the findings for the notion of grasping synergies are discussed. PMID:15912369

Gao, Fan; Latash, Mark L.; Zatsiorsky, Vladimir M.

2010-01-01

2

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

3

Industrial Energy Conservation, Forced Internal Recirculation Burner  

SciTech Connect

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

Joseph Rabovitser

2003-06-19

4

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

Federal Register 2010, 2011, 2012, 2013

...International Special Operations Forces Week Capability Exercise, Seddon Channel...International Special Operations Forces Week Capability Exercise. The exercise is scheduled...International Special Operations Forces Week Capability Exercise is scheduled to...

2012-05-21

5

Self-force as probe of internal structure  

E-print Network

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 1/r, with r denoting the radial position of the charge outside the body. To the leading order, the self-force scales as 1/r^3 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, 1/r^5, 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.

Soichiro Isoyama; Eric Poisson

2012-05-06

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

Charge; NSB Task Force on International Issues in Science and Engineering  

NSF Publications Database

... NSB Task Force on International Issues in Science and Engineering Date: February 18, 1999 NSB-99-32 ... February 18, 1999 Charge NSB Task Force on International Issues in Science and Engineering The ...

8

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

9

Ultrastable combined atomic force and total internal fluorescence microscope  

NASA Astrophysics Data System (ADS)

Combining atomic force microscope (AFM) with other microscopy techniques has expanded the range of potential applications for single molecule investigations dramatically. Particularly hybrid instruments with total internal reflection fluorescence (TIRF) excitation have opened new routes in life sciences. Here we present a novel design for such a hybrid microscope, which overcomes the limitations of conventional combinations caused by their limited mechanical stability. A thorough analysis of the noise spectra and a comparison of the different designs and the different operation modes are given. With this instrument we demonstrate single molecule manipulation by AFM and simultaneous TIRF imaging.

Gumpp, H.; Stahl, S. W.; Strackharn, M.; Puchner, E. M.; Gaub, H. E.

2009-06-01

10

Report of the ACR task force on international teleradiology.  

PubMed

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

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

2005-02-01

11

Management of venous edema: insights from an international task force.  

PubMed

An International Task Force made up of a panel of 16 experts has reviewed and objectively evaluated all aspects of chronic venous disease of the leg (CVDL). All available publications on CVDL from 1983 to 1997 were identified through computerized search in Medline and by a manual search. Next, three different screenings were performed in order to select only relevant papers providing a level of scientific evidence that was considered moderate to strong. Final conclusions and further therapeutic recommendations were made based on these publications. Medication, compression, local therapy, sclerotherapy, and surgery are the accepted available therapeutic options for CVDL. For edema, the following recommendations can be made: edema is an early sign of CVDL, but before starting any treatment, nonvenous causes of edema should be excluded. Medication and compression are the therapeutic options for edema that are accepted by the Task Force. Evaluation of their efficacy is based on objective measures of edema. Several well-conducted, placebo-controlled trials have shown efficacy of drugs such as micronized purified flavonoid fraction, rutosides, calcium dobesilate, and coumarin rutin. Graduated compression stockings have been shown to be effective; compression needs to be exerted at least at 35 mm Hg. Bandages, if properly applied, both fixed and stretched, can produce favorable results. Sclerotherapy or surgery is not indicated unless there is saphenofemoral or saphenopopliteal reflux. In the absence of such reflux or following deep venous thrombosis, there is no evidence to support sclerotherapy or surgery. PMID:10667638

Clement, D L

2000-01-01

12

Redesigning Residency Training in Internal Medicine: The Consensus Report of the Alliance for Academic Internal Medicine Education Redesign Task Force  

Microsoft Academic Search

Because of numerous criticisms of the content and structure of residency training, redesigning graduate medical education (GME) has become a high priority for the internal medicine community. From 2005 to 2007, the leadership of the internal medicine community, working under the auspices of the Alliance for Academic Internal Medicine Education Redesign Task Force, developed six recommendations it will pursue to

Frederick J. Meyers; Steven E. Weinberger; John P. Fitzgibbons; Jeffrey Glassroth; F. Daniel Duffy; Charles P. Clayton

2007-01-01

13

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

14

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. PMID:24910656

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

2013-01-01

15

Forced Marriage as a Harm in Domestic and International Law  

Microsoft Academic Search

This article reports on our analysis of 120 refugee cases from Australia, Canada, and Britain where an actual or threatened forced marriage was part of the claim for protection. We found that forced marriage was rarely considered by refugee decision makers to be a harm in and of itself. This finding contributes to understanding how gender and sexuality are analysed

Catherine Dauvergne; Jenni Millbank

2010-01-01

16

On the calculation of internal forces in mechanically stressed polyatomic molecules  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

17

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

PubMed

We discuss how to define and to compute internal forces in a molecule subjected to mechanical stress. Because of the inherently many-body character of intramolecular interactions, internal forces cannot be uniquely defined without specifying a set of internal coordinates used to describe the molecular structure. When such a set is comprised of 3N - 6 interactomic distances (N being the number of atoms) and includes the bond lengths of interest, we show that the associated forces, while satisfying the equation F = ?V/?R (where R is the bond length, F is the internal force in this bond, and V is the potential energy of the molecule), can be determined from the molecular geometry alone. We illustrate these ideas using several toy models ranging from small molecules to a graphene sheet and show that the magnitude of the internal force in a bond is not necessarily a good predictor of its strength in response to mechanical loading. At the same time, analysis of internal forces reveals interesting phenomena such as the force multiplication effect, where weak external forces may, e.g., be used to break strong bonds, and offers insight into the catch-bond phenomenon where chemical reactivity is suppressed through application of a force. PMID:25296792

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

2014-10-01

18

Atomic force microscopy to detect internal live processes in insects M. E. Dokukin,1  

E-print Network

Atomic force microscopy to detect internal live processes in insects M. E. Dokukin,1 N. V. Guz,1 S from internal live processes of insects. With a specially designed AFM stage to keep an insect motion partially restricted, the AFM can record internal oscillations on different parts of the insect. We

Sokolov, Igor

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. PMID:23280647

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

2013-01-01

20

Reflections on a Seminal Force in International Accounting  

ERIC Educational Resources Information Center

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

Cascini, Karen T.

2007-01-01

21

The Police Use of Deadly Force: International Comparisons  

Microsoft Academic Search

While the societies of the United States of America and Canada are similar in many ways, recent research has noted significant differences in the rates of extreme violence between the two nations. Extreme violence includes the police use of deadly force, the murder of police officers by an assailant, the homicide rate of the general population and violent crime such

Rick Parent

2006-01-01

22

International law and the preemptive use of military force  

Microsoft Academic Search

Under the UN Charter paradigm, unilateral preemptive force without an imminent threat is clearly unlawful. But what is imminent? For all practical purposes, the charter framework is, and has been, dead. The United States should take the lead to improve it.

Anthony Clark Arend

2003-01-01

23

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

24

Legitimating the Use of Force in International Politics: A Communicative Action Perspective  

Microsoft Academic Search

The legal provisions of the United Nations Charter offer imprecise and insufficient criteria for discriminating properly between legitimate vs illegitimate uses of force. The conflation of the concept of the legitimacy of the use of force with what is lawful, as agreed upon by a small number of major international actors, overlooks those situations in which legal standards are rendered

Corneliu Bjola

2005-01-01

25

Researching the use of force: the background to the international project  

Microsoft Academic Search

This article provides the background to an international project on use of force by the police that was carried out in seven\\u000a countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on\\u000a the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has

Philip Stenning; Christopher Birkbeck; Otto Adang; David Baker; Thomas Feltes; Luis Gerardo Gabaldón; Maki Haberfeld; Eduardo Paes Machado; P. A. J. Waddington

2009-01-01

26

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

27

Comparative analysis of internal friction and natural frequency measured by free decay and forced vibration  

SciTech Connect

Relations between various values of the internal friction (tg{delta}, Q{sup -1}, Q{sup -1*}, and {lambda}/{pi}) measured by free decay and forced vibration are analyzed systemically based on a fundamental mechanical model in this paper. Additionally, relations between various natural frequencies, such as vibration frequency of free decay {omega}{sub FD}, displacement-resonant frequency of forced vibration {omega}{sub d}, and velocity-resonant frequency of forced vibration {omega}{sub 0} are calculated. Moreover, measurement of natural frequencies of a copper specimen of 99.9% purity has been made to demonstrate the relation between the measured natural frequencies of the system by forced vibration and free decay. These results are of importance for not only more accurate measurement of the elastic modulus of materials but also the data conversion between different internal friction measurements.

Wang, Y. Z.; Ding, X. D.; Xiong, X. M.; Zhang, J. X. [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China) and Department of Physics, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China)

2007-10-15

28

Force.  

ERIC Educational Resources Information Center

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

Gamble, Reed

1989-01-01

29

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

ERIC Educational Resources Information Center

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

Park, Elisa L.

2009-01-01

30

Police officer characteristics and internal affairs investigations for use of force allegations  

Microsoft Academic Search

The purpose of the study was to investigate whether there was a relationship between police officer characteristics (e.g., experience, race, gender, age) and internal affairs investigations for allegations of use of force. Cumulative logistic regression models were fitted to data extracted from personnel files of officers employed by the Riverside County Sheriff's Department for the years 1996 through 2000. Analysis

James P. McElvain; Augustine J. Kposowa

2004-01-01

31

Simulating the winter North Atlantic Oscillation: the roles of internal variability and greenhouse gas forcing  

Microsoft Academic Search

Analysis of simulations with seven coupled climate models demonstrates that the observed variations in the winter North Atlantic Oscillation (NAO), particularly the increase from the 1960s to the 1990s, are not compatible with either the internally generated variability nor the response to increasing greenhouse gas forcing simulated by these models. The observed NAO record can be explained by a combination

T. J. Osborn

2004-01-01

32

The Legality of the International Use of Force by and from States  

Microsoft Academic Search

The question posed is the most important issue in world politics: under what circumstances may states lawfully resort to the unilateral (and international) use of force? If Articles 2(4) and 51 of the Charter of the United Nations were in fact part of the living law of the world community, the question would be easy to answer. Then one could

Eugene V. Rostow

1985-01-01

33

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

PubMed

Despite the well-recognized role of lifting in back injuries, the relative biomechanical merits of squat versus stoop lifting remain controversial. In vivo kinematics measurements and model studies are combined to estimate trunk muscle forces and internal spinal loads under dynamic squat and stoop lifts with and without load in hands. Measurements were performed on healthy subjects to collect segmental rotations during lifts needed as input data in subsequent model studies. The model accounted for nonlinear properties of the ligamentous spine, wrapping of thoracic extensor muscles to take curved paths in flexion and trunk dynamic characteristics (inertia and damping) while subject to measured kinematics and gravity/external loads. A dynamic kinematics-driven approach was employed accounting for the spinal synergy by simultaneous consideration of passive structures and muscle forces under given posture and loads. Results satisfied kinematics and dynamic equilibrium conditions at all levels and directions. Net moments, muscle forces at different levels, passive (muscle or ligamentous) forces and internal compression/shear forces were larger in stoop lifts than in squat ones. These were due to significantly larger thorax, lumbar and pelvis rotations in stoop lifts. For the relatively slow lifting tasks performed in this study with the lowering and lifting phases each lasting approximately 2 s, the effect of inertia and damping was not, in general, important. Moreover, posterior shift in the position of the external load in stoop lift reaching the same lever arm with respect to the S1 as that in squat lift did not influence the conclusion of this study on the merits of squat lifts over stoop ones. Results, for the tasks considered, advocate squat lifting over stoop lifting as the technique of choice in reducing net moments, muscle forces and internal spinal loads (i.e., moment, compression and shear force). PMID:17103232

Bazrgari, Babak; Shirazi-Adl, Aboulfazl; Arjmand, Navid

2007-05-01

34

International confederation for cleft lip and palate and related craniofacial anomalies task force report: holistic outcomes.  

PubMed

Objective : This paper describes the process and outcomes of the 2013 American Cleft Palate-Craniofacial Association task force on Holistic Outcomes. The goals and membership of the task force are presented. Methods : Using internet communication, the group introduced themselves, shared ideas and information related to holistic assessment and implementation of using a validated holistic measure, the Child Oral Health Impact Profile (COHIP) at participating international sites. Results : Data from the sites were analyzed using descriptive statistics. Administration of the COHIP was successful. It varied from self-completion as well as verbal presentation due to language differences and a function of the short time period to complete collection. Additionally qualitative comments were reported by the task force site directors. Conclusions : Future directions for holistic assessment and communication among task force members and sites were discussed at the Congress and are presented in this report. PMID:25105439

Broder, Hillary L

2014-11-01

35

Forces  

NSDL National Science Digital Library

This page provides the background for a basic laboratory exercise on force. Included is an explanation of force and vector components and an interactive java applet to demonstrate vectors and vector algebra.

Sorokin, Vladimir

2004-11-28

36

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

37

Force  

NSDL National Science Digital Library

Instructions: This is a webquest designed to help students understand force. It is specifically meant to teach the idea that the greater the force applied to an object the greater the change in speed or direction of the object depending on the mass. This is also known as Newton's Second Law of Motion. Lets Learn about Force! For this project your students will understand force. They will use Newton's second law to solve the problem presented. UT Core Curriculum: Science 3rd Grade. Standard 3- Students will understand the relationship between the force applied to an object and resulting motion of the ...

Brownie, Mrs.

2010-04-07

38

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

39

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

40

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

PubMed

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

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

2010-11-16

41

Analysis on driving forces of oil pumps for internal combustion engines  

SciTech Connect

Measures to reduce friction losses for internal combustion engines have been promoted as a means to meet the recent socioeconomical demand for energy saving. This paper describes a unique study on oil pump driving forces as a part of such efforts. In this study, oil pump driving forces are divided into (1) pumping work, (2) gear intermeshing loss, (3) resistance by the viscosity of lubricating oil, (4) mechanical loss and (5) bearing friction loss. Individual driving forces have been analyzed by respective theories, which are synthesized into a theoretical equation. The comparison between the theoretically calculated values and measured values obtained by the tests has revealed that they are in good agreement, as being described in the text of the paper.

Baba, Y.; Hoshi, M.

1986-01-01

42

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

43

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

E-print Network

The fact that the Earth climate is a highly complex dynamical system is well-known. In the last few decades a lot 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 in understanding the role of atmospheric variability, and construct climate networks representing internal and forced variability. In the connectivity of these networks we assess the influence of two main indices, NINO3.4 and the North Atlantic Oscillation (NAO), by calculating the networks from time-series where these indices were linearly removed. We find that the connectivity of the forced variability network is heavily affected by ``El Ni\\~no'': 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 Ni\\~no'', particularly on interannual time scales. On the contrary, in the internal variability network (independent of sea surface temperature forcing) we find that the links are significantly affected by NAO with a maximum in intra-annual time scales. While the strongest non-local links found are those forced by the ocean, we show that there are also strong teleconnections due to internal atmospheric variability.

J. Ignacio Deza; Cristina Masoller; Marcelo Barreiro

2013-11-13

44

Foraging at the edge of chaos: internal clock versus external forcing.  

PubMed

Activity rhythms in animal groups arise both from external changes in the environment, as well as from internal group dynamics. These cycles are reminiscent of physical and chemical systems with quasiperiodic and even chaotic behavior resulting from "autocatalytic" mechanisms. We use nonlinear differential equations to model how the coupling between the self-excitatory interactions of individuals and external forcing can produce four different types of activity rhythms: quasiperiodic, chaotic, phase locked, and displaying over or under shooting. At the transition between quasiperiodic and chaotic regimes, activity cycles are asymmetrical, with rapid activity increases and slower decreases and a phase shift between external forcing and activity. We find similar activity patterns in ant colonies in response to varying temperature during the day. Thus foraging ants operate in a region of quasiperiodicity close to a cascade of transitions leading to chaos. The model suggests that a wide range of temporal structures and irregularities seen in the activity of animal and human groups might be accounted for by the coupling between collectively generated internal clocks and external forcings. PMID:23848927

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

2013-06-28

45

Long-range memory in internal and forced dynamics of millennium-long climate model simulations  

NASA Astrophysics Data System (ADS)

Northern Hemisphere (NH) temperature records from a palaeoclimate reconstruction and a number of millennium-long climate model experiments are investigated for long-range memory (LRM). The models are two Earth system models and two atmosphere-ocean general circulation models. The periodogram, detrended fluctuation analysis and wavelet variance analysis are applied to examine scaling properties and to estimate a scaling exponent of the temperature records. A simple linear model for the climate response to external forcing is also applied to the reconstruction and the forced climate model runs, and then compared to unforced control runs to extract the LRM generated by internal dynamics of the climate system. The climate models show strong persistent scaling with power spectral densities of the form S(f) ~ f -? with 0.8 < ? < 1 on timescales from years to several centuries. This is somewhat stronger persistence than found in the reconstruction (? ? 0.7). We find no indication that LRM found in these model runs is induced by external forcing, which suggests that LRM on sub-decadal to century time scales in NH mean temperatures is a property of the internal dynamics of the climate system. Reconstructed and instrumental sea surface temperature records for a local site, Reykjanes Ridge, are also studied, showing that strong persistence is found also for local ocean temperature.

Østvand, L.; Nilsen, T.; Rypdal, K.; Divine, D.; Rypdal, M.

2014-08-01

46

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

47

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

PubMed Central

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

Thomson, George; Wilson, Nick

2005-01-01

48

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

49

Research priorities and plans for the International Space Station—Results of the 'REMAP' task force  

NASA Astrophysics Data System (ADS)

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.

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

2003-08-01

50

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

NASA Astrophysics Data System (ADS)

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

Kicza, M.

2002-01-01

51

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

PubMed

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

Kicza, M; Erickson, K; Trinh, E

2003-01-01

52

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

53

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

54

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

55

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

56

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.

57

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

PubMed Central

Objective The risk-benefit profile of antidepressant medications in bipolar disorder is controversial. When conclusive evidence is lacking, expert consensus can guide treatment decisions. The International Society for Bipolar Disorders (ISBD) convened a task force to seek consensus recommendations on the use of antidepressants in bipolar disorders. Method An expert task force iteratively developed consensus through serial consensus-based revisions using the Delphi method. Initial survey items were based on systematic review of the literature. Subsequent surveys included new or reworded items and items that needed to be rerated. This process resulted in the final ISBD Task Force clinical recommendations on antidepressant use in bipolar disorder. Results There is striking incongruity between the wide use of and the weak evidence base for the efficacy and safety of antidepressant drugs in bipolar disorder. Few well-designed, long-term trials of prophylactic benefits have been conducted, and there is insufficient evidence for treatment benefits with antidepressants combined with mood stabilizers. A major concern is the risk for mood switch to hypomania, mania, and mixed states. Integrating the evidence and the experience of the task force members, a consensus was reached on 12 statements on the use of antidepressants in bipolar disorder. Conclusions Because of limited data, the task force could not make broad statements endorsing antidepressant use but acknowledged that individual bipolar patients may benefit from antidepressants. Regarding safety, serotonin reuptake inhibitors and bupropion may have lower rates of manic switch than tricyclic and tetracyclic antidepressants and norepinephrine-serotonin reuptake inhibitors. The frequency and severity of antidepressant-associated mood elevations appear to be greater in bipolar I than bipolar II disorder. Hence, in bipolar I patients antidepressants should be prescribed only as an adjunct to mood-stabilizing medications. PMID:24030475

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

2014-01-01

58

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

59

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

60

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

PubMed

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

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

2014-10-01

61

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

62

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

63

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

64

Spectral evolution of bottom-forced internal waves J.A. MacKinnon and K.B. Winters  

E-print Network

to near-inertial waves, while at mid-latitude energy remains concentrated near the forcing frequency (M2-scale oceanographic community. The relatively low magnitude of typical thermocline diffusivity (5Ã?10-6 m2 s-1 ) has with a narrowband, upwardly propagating internal tide as a (near) bottom boundary condition. Three simulations

MacKinnon, Jennifer

65

Internal forces in nondegenerate two-dimensional electron systems C. Fang-Yen* and M. I. Dykman  

E-print Network

large, 10, where e2 ns 1/2 /T. 1 Therefore the electron system is strongly correlated. It is a normalInternal forces in nondegenerate two-dimensional electron systems C. Fang-Yen* and M. I. Dykman and cyclotron resonance of nondegenerate electron systems; they are also known to provide an important

Fang-Yen, Christopher

66

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

PubMed Central

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

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

2014-01-01

67

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; Åkerman, Björn; Nordén, Bengt

2014-01-01

68

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

PubMed Central

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

Oreopoulos, John; Yip, Christopher M.

2009-01-01

69

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

70

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

71

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

Microsoft Academic Search

Recent events in the International Space Station (ISS) Program have resulted in the necessity to re-examine the research priorities and research plans for future years. Due to both technical and fiscal resource constraints expected on the International Space Station, it is imperative that research priorities be carefully reviewed and clearly articulated. The U.S. President's Budget language for 2003 states that

M. Kicza

2002-01-01

72

Research priorities and plans for the International Space Station—Results of the ‘REMAP’ task force  

Microsoft Academic Search

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

K. Erickson; E. Trinh

2003-01-01

73

1995 IEEE International Conference on Robotics and Automation Experiments in Adaptive ModelBased Force Control  

E-print Network

@arimotolab.t.u­tokyo.ac.jp Fumio Ozaki Energy and Mechanical Research Laboratory Research and Development Center Toshiba Corporation 4­1 Ukishima­cho, Kawasaki­ku Kawasaki 210, Japan. Email: 000013135207@tg­mail.toshiba:llw@jhu.edu. FORCE SENSOR 1 2 3 RIGID SURFACE DIRECT DRIVE JOINTS Figure 1. The Toshiba Direct Drive Arm. algorithm

Whitcomb, Louis L.

74

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

NASA Astrophysics Data System (ADS)

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

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

75

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

76

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

77

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

ERIC Educational Resources Information Center

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

Bell, Larry G.

78

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

79

Report of the Obstetric APS Task Force: 13th International Congress on Antiphospholipid Antibodies, 13th April 2010.  

PubMed

The Obstetric APS Task Force of the 13th International Congress identified and discussed five general topics within 'Obstetric' Antiphospholipid Syndrome (APS) that contained areas of controversy or uncertainty: recurrent early miscarriage (REM), fetal death, delivery <34 weeks for severe preeclampsia or placental insufficiency, postpartum care, and long-term implications and care. The Task Force concluded that the frequency with which women with REM have a high titer of antiphospholipid antibodies (aPL) or lupus anticoagulant (LA) is somewhat controversial, especially with regard to the diagnostic titers required by the current international criteria for APS. Also, treatment trials involving heparin differ from one another with regard to the patients included and the outcomes achieved. Similarly, the frequency with which women with fetal death or delivery <34 weeks for severe preeclampsia or placental insufficiency have a high titer of aPL or LA is poorly defined, and there is no level I evidence to guide treatment in either group. Suggestions for future studies with regard to both REM and fetal death or delivery <34 weeks for severe preeclampsia or placental insufficiency were discussed and are outlined below. Postpartum and long-term care in women with APS diagnosed solely for obstetric criteria has been largely guided by expert opinion, and systematic evaluations of these populations would be welcome. PMID:21303832

Branch, W

2011-02-01

80

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

81

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

PubMed Central

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

Devonshire, Elizabeth; Siddall, Philip J

2011-01-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2003-05-01

83

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. However, our understanding of the origin of the MCA is still fragmentary. Simulations using coupled climate models typically fail to reproduce many key features, both in the magnitude and timing, of the MCA. Using model simulations constrained by data assimilation, we obtain here the spatial pattern of temperature changes in the MCA that is most consistent with forcing estimates, model physics and the empirical information contained in paleoclimate proxy records. These experiments demonstrate that the observed spatial temperature pattern of the MCA can be explained by a simple thermodynamical response to relatively weak changes in radiative forcing combined with a modification of the atmospheric circulation, similar to the positive phase of the so-called Arctic Oscillation, and with northward shifts in the position of ocean western boundary current systems including the Gulf Stream and Kuroshio currents. The mechanisms underlying the MCA are thus quite different from anthropogenic mechanisms responsible for modern global warming.

Goosse, H.; Crespin, E.; Dubinkina, S.; Loutre, M.; Mann, M. E.; Renssen, H.; Sallaz-Damaz, Y.; Shindell, D. T.

2011-12-01

84

Specific heat, internal energy, and thermodynamic Casimir force in the neighborhood of the ? transition  

NASA Astrophysics Data System (ADS)

We discuss the relation of the excess specific heat, the excess energy per area, and the thermodynamic Casimir force in thin films. A priori these quantities depend on the reduced temperature t and the thickness L0 of the film. However finite-size scaling theory predicts that the scaling functions h?(x) , h'(x) , and ?(x) of these quantities depend only on the combination x=t[L0/?0]1/? , where ? is the critical exponent and ?0 the amplitude of the correlation length. Furthermore, the finite-size scaling function ?(x) of the thermodynamic Casimir force per area can be expressed in terms of the scaling functions h'(x) and h(x) of the excess energy per area and the excess free energy per area. Here we study this relation at the example of thin films of the improved two-component ?4 model on the simple cubic lattice. Note that this model undergoes a second-order phase transition that belongs to the three-dimensional XY universality class. First we simulate films with periodic boundary conditions in the short direction and a thickness up to L0=13 lattice spacings. We find that even for these rather thin films, the predictions of finite-size scaling are well satisfied. We repeat the analysis for films with free boundary conditions. To this end we use Monte Carlo data for the energy per area obtained in previous work. It turns our that corrections to scaling caused by the boundary conditions are very prominent in this case. Only by taking into account these corrections we are able to obtain ?(x) from the excess energy. Finally we repeat this exercise using experimental data for the excess specific heat of H4e films near the ? transition. The finite-size scaling behavior of the excess specific heat is governed by h?(x) , which is proportional to the scaling function f2 discussed in the literature.

Hasenbusch, Martin

2010-04-01

85

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

SciTech Connect

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

Abe, S.

1987-11-24

86

Forced responses of solid axially polarized piezoelectric ceramic finite cylinders with internal losses.  

PubMed

A method is presented to determine the forced responses of piezoelectric cylinders using weighted sums of only certain exact solutions to the equations of motion and the Gauss electrostatic conditions. One infinite set of solutions is chosen such that each field variable is expressed in terms of Bessel functions that form a complete set in the radial direction. Another infinite set of solutions is chosen such that each field variable is expressed in terms of trigonometric functions that form a complete set in the axial direction. Another solution is used to account for the electric field that can exist even when there is no vibration. The weights are determined by using the orthogonal properties of the functions and are used to satisfy specified, arbitrary, axisymmetric boundary conditions on all the surfaces. Special cases including simultaneous mechanical and electrical excitation of cylinders are presented. All numerical results are in excellent agreement with those obtained using the finite element software ATILA. For example, the five lowest frequencies at which the conductance and susceptance of a stress-free cylinder, of length 10 mm and radius 5 mm, reach a local maximum or minimum differ by less than 0.01% from those computed using ATILA. PMID:16018468

Ebenezer, D D; Ravichandran, K; Ramesh, R; Padmanabhan, Chandramouli

2005-06-01

87

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

PubMed

The assigned objective for the Task Force Beyond Eurocleft was "to make recommendations for initiations of local and/or participation in multi-national cleft outcome studies and consist of individuals from the European experience with cleft outcome studies (Scandcleft, Eurocleft) and those who have initiated, or intend to initiate, similar studies in other geographical areas." By May 2013 the Task Force (TF) consisted of 183 members from 59 countries. It was agreed that this initiative should be truly global and include all cleft specialties as well as representatives from cleft support groups in recognition of the huge commitment for improving cleft care worldwide. The vision for this group is to build a dynamic, well-functioning TF that will work globally and be multidisciplinary with inclusive and respectful behavior to improve care for all individuals born with cleft lip and/or palate. As there is a large diversity in needs and interest in the group a range of parallel approaches would be required depending on the experience, resources, and challenges of regions, teams, and individuals. Important ideas for future work were: (1) Work on a global survey of access, existing outcome studies, current collaborations, and lessons learned. (2) Work towards the creation of a lasting, living resource for newcomers to intercenter collaboration that is kept fresh with new reports, copies of relevant publications, model grant applications, and a list of volunteers with the right experience to provide support and guidance for new initiatives. (3) Develop simple online training modules to provide information about the benefits and principles of multidisciplinary care, collaborative data collection and auditing short and longer-term outcomes. (4) Establish subgroups that will work within all regions of the world with regional and national leaders identified. An evaluation of current standards of care should be undertaken and country/region specific remedies to optimize treatment outcome suggested. (5) Reach agreement on minimum standards of care, minimum record collection, and reach consensus on simple outcome measures in all disciplines. This should include all cleft types and all ages. These standards could be used to encourage governments to fund multidisciplinary care. (6) Teams will be encouraged to start and continue recordkeeping using simple and agreed protocols, according to agreed standards of minimum records and later share their data with other teams and then, embark on outcome studies. (7) Teams already active in research should: Create a register for cleft professionals and teams to reach agreement of contemporary and comprehensive multidisciplinary outcome measures, explore the possibilities using modern technology and plan large multi-national studies. A patient/parent centered data collection should always be included. These studies need funding. One task could also be exploring whether health care at a distance could be initiated using new technology. PMID:25244656

Semb, Gunvor

2014-11-01

88

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

89

Quartic canonical force field in curvilinear internal coordinates for XY3 (D3h) molecules. The case of the BH3 molecule.  

PubMed

Using the canonical force field theory, expressions of quadratic, cubic, and quartic canonical force constants are obtained for XY3 (D3h) 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 (D3h) 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 (D3h) 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

90

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. PMID:21069716

Arnautova, Yelena A.; Abagyan, Ruben A.

2010-01-01

91

New York Airports Data Package Number 3, John F. Kennedy International Airport, La Guardia Airport. Airport Improvement Task Force Delay Studies.  

National Technical Information Service (NTIS)

The New York Data Package No. 3 contains preliminary Data Package No. 3 for John F. Kennedy International (JFK) and LaGuardia (LGA) Airports for use during the fourth New York Task Force Meeting on October 17, 1978. Attachment A contains the results of th...

1978-01-01

92

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

93

Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis.  

PubMed

Atopic dermatitis (AD) is a common chronic relapsing pruritic skin disease of dogs for which treatment has varied over time and geographical location. Recent high quality randomized controlled trials and systematic reviews have established which drugs are likely to offer consistent benefit. The International Task Force for Canine AD currently recommends a multi-faceted approach to treat dogs with AD. Acute flares should be treated with a combination of nonirritating baths and topical glucocorticoids, once an attempt has been made to identify and remove the suspected causes of the flare. Oral glucocorticoids and antimicrobial therapy must be added when needed. In dogs with chronic AD, a combination of interventions should be considered. Again, factors that trigger flares of AD must be identified and, if possible, avoided. Currently recognized flare factors include food, flea and environmental allergens, Staphylococcus bacteria and Malassezia yeast. Skin and coat hygiene and care must be improved by bathing with nonirritating shampoos and dietary supplementation with essential fatty acids. The severity of pruritus and skin lesions can be reduced with a combination of anti-inflammatory drugs. Currently, medications with good evidence of high efficacy include topical and oral glucocorticoids, and calcineurin inhibitors such as oral ciclosporin and topical tacrolimus. The dose and frequency of administration of these drugs should be tailored to each patient considering each drug's efficacy, adverse effects and cost. Allergen-specific immunotherapy should be offered, whenever feasible, in an attempt to prevent recurrence of clinical signs upon further exposure to environmental allergens to which the patient is hypersensitive. PMID:20456716

Olivry, Thierry; DeBoer, Douglas J; Favrot, Claude; Jackson, Hilary A; Mueller, Ralf S; Nuttall, Tim; Prélaud, Pascal

2010-06-01

94

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

95

Semidirect radiative forcing of internal mixed black carbon cloud droplet and its regional climatic effect over China  

Microsoft Academic Search

Black carbon (BC) is one of the most important atmospheric aerosols. It can exert a positive radiative forcing by absorbing solar radiation and a negative radiative forcing by acting as cloud condensation nuclei (CCN) at the top of the atmosphere (TOA). Furthermore, cloud droplets with BC can absorb more solar radiation and reduce their single-scattering albedo (SSA), leading to a

B. L. Zhuang; L. Liu; F. H. Shen; T. J. Wang; Y. Han

2010-01-01

96

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

PubMed

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

Kar, Julia; Quesada, Peter M

2012-08-01

97

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

ERIC Educational Resources Information Center

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

Rostow, Eugene V.

98

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

PubMed

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

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

2013-01-01

99

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

ERIC Educational Resources Information Center

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

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

100

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

101

A simulation of muscle force and internal kinematics of extensor carpi radialis brevis during backhand tennis stroke: implications for injury  

Microsoft Academic Search

Objective.The purpose of this work was use a computer simulation of the action of extensor carpi radialis brevis during a typical backhand tennis stroke of novice and advance players to examine a potential mechanism of injury.Design.This study uses established kinematic data in conjunction with a computer model to give a time varying description of muscle force and length changes.Background. Lateral

Stephan Riek; Arthur E. Chapman; Ted Milner

1999-01-01

102

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

ERIC Educational Resources Information Center

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

Lane, Liane Wardlow; Ferreira, Victor S.

2008-01-01

103

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

PubMed

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

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

2013-01-01

104

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

PubMed

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

Adouni, M; Shirazi-Adl, A

2014-05-01

105

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

PubMed Central

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

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

2014-01-01

106

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

NASA Astrophysics Data System (ADS)

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

Øien, Alf H.

2008-09-01

107

Seasonal Effects of Indian Ocean Freshwater Forcing in a Regional Coupled Model* International Pacific Research Center, University of Hawaii at Manoa, Honolulu, Hawaii  

E-print Network

Seasonal Effects of Indian Ocean Freshwater Forcing in a Regional Coupled Model* HYODAE SEO form 30 July 2009) ABSTRACT Effects of freshwater forcing from river discharge into the Indian Ocean-ocean strat- ification and increases the SST near the river mouths where the freshwater forcing is largest

Xie, Shang-Ping

108

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

SciTech Connect

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

Unseren, M.A.

1997-09-01

109

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

110

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. PMID:23543826

Hajian-Tilaki, Karimollah; Heidari, Behzad

2013-01-01

111

International International  

E-print Network

students from over 120 countries. Our international reputation for academic excellence attracts students's life in Sheffield like? How does the University compare to other British universities? This guide has the answers, and a lot more besides. If you think Sheffield is right for you, visit our website for more

Li, Yi

112

International International  

E-print Network

Skills Inventory Motivational Factors Narrowing the field Aligning credentials Optimizing documents II ID feelings to guide decisions. 2. Self-management -- involves controlling one's emotions and impulses. © 2009 Egon Zehnder International10 #12;· People demonstrating this behavior are effective in working

Puglisi, Joseph

113

Force propagation and force generation in cells.  

PubMed

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

Jonas, Oliver; Duschl, Claus

2010-09-01

114

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

115

Forced and Internal Twentieth-Century SST Trends in the North Atlantic* MINGFANG TING, YOCHANAN KUSHNIR, RICHARD SEAGER, AND CUIHUA LI  

E-print Network

since then. This natural variation, referred to previously as the Atlantic Multidecadal Oscillation (AMO to detect and attribute long-term (multidecadal) twentieth-century North Atlantic (NA) SST changes multidecadal ``oscillation'' that is outside of the range of the model-simulated, forced com- ponent and most

116

EULAR recommendations for the management of knee osteoarthritis: report of a task force of the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT)  

Microsoft Academic Search

BACKGROUNDOsteoarthritis (OA) is the most common joint disease encountered throughout Europe. A task force for the EULAR Standing Committee for Clinical Trials met in 1998 to determine the methodological and logistical approach required for the development of evidence based guidelines for treatment of knee OA. The guidelines were restricted to cover all currently available treatments for knee OA diagnosed either

A Pendleton; N Arden; M Dougados; M Doherty; B Bannwarth; J W J Bijlsma; F Cluzeau; C Cooper; P A Dieppe; K-P Günther; H J Hauselmann; G Herrero-Beaumont; P M Kaklamanis; B Leeb; M Lequesne; S Lohmander; B Mazieres; E-M Mola; K Pavelka; U Serni; B Swoboda; A A Verbruggen; G Weseloh; I Zimmermann-Gorska

2000-01-01

117

Force field calculation for inplane vibrations of ethylene using cndo \\/Force method  

Microsoft Academic Search

cndo\\/Force method is used to evaluate redundancy-free internal valence force field (rfivff) for inplane vibrations of ethylene. The bending force constants, the stretch-band and bend-bend interaction force constants\\u000a are predicted reasonably well in magnitude and sign by this method; whereas stretching force constants and stretch-stretch\\u000a interactions are overestimated. Initial force field is set up by transferring stretching force constants from

A Jothi; G Shanmugam; A Annamalai; Surjit Singh

1982-01-01

118

Earth Force  

NSDL National Science Digital Library

"Earth Force engages young people as active citizens who improve the environment and their communities now and in the future." Educators can learn about Earth Force's three programs: Community Action and Problem solving (CAPS), the Global Rivers Environmental Education Network (GREEN), and Earth Force After School. Users can discover students' many accomplishments such as creating reusable fabric grocery bags, recycling cell phones and ink cartridges to earn money, and cleaning up litter. The Tools for Teachers section offers evaluation results, a quality rubric, and a description of the six-step Earth Force community action and problem-solving process.

119

EFFECTS OF A BIRD HAZARD REDUCTION FORCE ON REDUCING BIRD\\/AIRCRAFT STRIKE HAZARDS AT THE ATLANTIC CITY INTERNATIONAL AIRPORT, NJ  

Microsoft Academic Search

Bird-aircraft strikes at the Atlantic City International Airport (ACY) increased from 18 in 1989 to 37 in 1990. The number of bird-aircraft strikes involving gulls (Larus spp.) during this time rose from 6 to 27, a 350% increase. The predominant species involved in bird strikes was the laughing gull (L. atricilla). Pursuant to an interagency agreement between the U.S. Department

Andy J. Montoney; H. Christopher Boggs

1993-01-01

120

Unbalanced Forces  

NSDL National Science Digital Library

The representation describes the effect of unbalanced forces on objects at rest and objects in motion in an animated slide show. This resource also includes an interactive test and review of the material. The slide show is accessed through a link marked "Unbalanced Forces" on the resource page, and the entire resource is downloadable, allowing users to run the slide show offline.

121

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

122

Buoyant Force  

NSDL National Science Digital Library

This activity is a lab where students gather data on buoyant force and height of and object being submerged in two different types of fluids. The slope of the buoyant force and height is proportional to the density of the fluid. Students compare the densities of the fluids calculated with the actual densities.

Renae Garski, Bigfork High School, Bigfork, MN, based on an original activity from Science Workshop, p. 115

123

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

...Organized Crime Drug Enforcement Task Force Fusion Center and International Organized Crime...Organized Crime Drug Enforcement Task Force Fusion Center, the International Organized...Organized Crime Drug Enforcement Task Force Fusion Center, the International...

2014-07-01

124

Force sensor  

DOEpatents

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

Grahn, A.R.

1993-05-11

125

Force sensor  

DOEpatents

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

Grahn, Allen R. (Salt Lake City, UT)

1993-01-01

126

Analysis of moving loads using force-based finite elements  

Microsoft Academic Search

An analysis method for moving loads computes the internal force history in a structural member at the integration points of force-based finite elements as opposed to the end forces of a refined displacement-based finite element mesh. The force-based formulation satisfies strong equilibrium of internal section forces with the element end forces and the moving load. This is in contrast with

Adrian Kidarsa; Michael H. Scott; Christopher C. Higgins

2008-01-01

127

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

128

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

129

Social force model for pedestrian dynamics  

Microsoft Academic Search

It is suggested that the motion of pedestrians can be described as if they would be subject to ``social forces.'' These ``forces'' are not directly exerted by the pedestrians' personal environment, but they are a measure for the internal motivations of the individuals to perform certain actions (movements). The corresponding force concept is discussed in more detail and can also

Dirk Helbing; Péter Molnár

1995-01-01

130

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?"

131

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.

132

Differential force balances during levitation  

NASA Astrophysics Data System (ADS)

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

Todd, Paul

133

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. PMID:19401690

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

134

INTERNATIONAL International Internship for  

E-print Network

OFFICE OF INTERNATIONAL AFFAIRS International Internship for Global Leadership Program Student Portugal ­ Laura Sieger Ukraine ­ Mary Brune 2012 Internship Locations #12;Dear Friends and Colleagues of Lehigh University: The International Internship for Global Leadership Program provides Lehigh students

Napier, Terrence

135

INTERNATIONAL International Student Office  

E-print Network

CENTER FOR INTERNATIONAL EDUCATION International Student Office The International Student Office from 48 countries. The ISO provides many services including recruitment, admission, orientation with several foreign uni- versities. Each of these agreements includes the possibility of faculty exchanges

Gering, Jon C.

136

Forces and Motion  

NSDL National Science Digital Library

Explore the forces at work when you try to push a filing cabinet. Create an applied force and see the resulting friction force and total force acting on the cabinet. Charts show the forces, position, velocity, and acceleration vs. time. View a Free Body Diagram of all the forces (including gravitational and normal forces).

Simulations, Phet I.; Reid, Sam; Podelefsky, Noah; Loeblein, Trish; Perkins, Kathy

2010-10-01

137

Anharmonic force field for methanol  

NASA Astrophysics Data System (ADS)

An ab initio quartic anharmonic force field for methanol has been calculated at the equilibrium position using the CCSD(T) method for the structure and the harmonic potential energy surface, and the MP4(SDQ) method for the anharmonic part of the surface. A triple zeta basis set was employed with symmetrized curvilinear internal valence coordinates in all calculations. The internal coordinate force field constants have been transformed into force constants in the dimensionless normal coordinate representation for various isotopomers. Vibrational term values for CH3OH, CH3OD, CD3OH, and CD3OD have been obtained using second order perturbation theory. Particular care has been devoted to the inclusion of Fermi resonance interactions between different vibrational states. A good accuracy has been achieved in the calculation of the fundamentals for all the isotopomers, the mean absolute error being 5.8 cm-1.

Miani, Andrea; Hänninen, Vesa; Horn, Matthias; Halonen, Lauri

138

Diamagnetic force on a flux tube  

Microsoft Academic Search

The diamagnetic force on a straight flux tube is elucidated. The case when the flux tube has a circular cross section is considered, and the result is generalized to the case of noncircular cross section. The result shows that when the external magnetic field is uniform, the diamagnetic force is simply equal to the vector multiplication of the internal conduction

T. Yeh

1983-01-01

139

Forced Marriage as a Crime against Humanity  

Microsoft Academic Search

Forced marriages are a pervasive feature of armed conflicts around the world, such as in Sierra Leone, Cambodia, Rwanda and Uganda. Despite forced marriage having been charged and recently affirmed as an international crime before the Special Court for Sierra Leone (SCSL), courts and commentators have paid little attention to examining its viability as a distinct category of crime in

Neha Jain

2008-01-01

140

Director of International Affairs POSITION ANNOUNCEMENT  

E-print Network

students in higher education. · Inform students of issues and legislation of importance, gather student to apply. The Director of the International Student Affairs Task Force shall assist ASOSU in promoting international students · Maintain the International Student Affairs Task Force Budget · Work 15 office hours per

141

Financial Action Task Force  

NSDL National Science Digital Library

Created in 1989, the Financial Action Task Force (FATF) is an inter-governmental body whose purpose is "the development and promotion of national and international policies to combat money laundering and terrorist financing." Users who are new to the site can get started quickly by looking over the "Quick Links" section on the right-hand side of the homepage. Here they will find a handbook that details how the FATF creates its profiles, information on the methodology, and primary recommendations for creating a coherent set of counter-measures against money laundering. Also, the site includes a "Publications" area, which contains short summaries of reports, along with annual reports dating from 1990 and newsletters from 2007. Finally, the site also contains a listing of recent news items and upcoming events and conferences sponsored by the FATF.

142

Force and Motion: Newton's First Law  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Force and Motion SciPack. It provides a conceptual and real-world understanding of Newton's First Law of Motion. All objects will maintain a constant speed and direction of motion unless an unbalanced outside force acts on it. When an unbalanced force acts on an object, its speed or direction (or both) will change. The tendency of objects to maintain a constant speed and direction of motion (velocity) in the absence of an unbalanced force is known as intertia. Even in the most familiar, every day situations, frictional forces can complicate the analysis of motion, although the basic principles still apply. Learning Outcomes:� Recognize and give examples of forces. � Recognize and give examples of balanced and unbalanced forces.� Equate the term "unbalanced force" with "a net force that does not equal zero."� Apply, in an informal way, Newton's first law. � Explain the role of the force of friction in determining how well Newton's first law seems to apply or not apply to a given physical situation. � Explain the reasoning Galileo used to justify the second part of Newton's first law.� Explain how the force of friction applies to the second part of Newton's first law.� Recognize the concept of inertia (as opposed to a force, momentum, etc.). � Recognize that an object at rest may have forces acting on it.� Distinguish between "impulse" and "sustained" forces (and recognize both).� Recognize that objects do not have internal forces that keep them moving.

National Science Teachers Association (NSTA)

2006-01-01

143

Operating internationally  

SciTech Connect

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

Seeley, R.S.

1994-02-01

144

Attentional Focusing Instructions and Force Production  

PubMed Central

Research progress assessing the role of attentional focusing instructions on skill acquisition and performance has lead researchers to apply this approach to force production tasks. Initial converging evidence indicates that force production tasks are sensitive to verbal instruction; externally focused instructions (onto movement outcomes, or onto the object force is being exerted against) are shown to be more beneficial than internally focused instructions (focusing attention onto the movements being executed). These benefits are observed for maximal and accurate force production, as well as the maintenance of force production in prolonged tasks. A range of mechanisms are identified supporting the proposal that an external focus promotes movement efficiency in line with energy and effort conservation. Future research is required to assess how this developing body of work interacts with the broader understanding of psychological and physiological factors implicated in the effective production, maintenance, and limitation of maximal or sub-maximal forces. PMID:21833266

Marchant, David C.

2010-01-01

145

Necessity and the Use of Force: A Special Regime  

Microsoft Academic Search

\\u000a This chapter examines the relevance of the principle of necessity to the international rules on the use of force. It claims\\u000a that necessity has been the source of the international rules on the use of force which as independent titles manifest themselves\\u000a in institutional as well as in customary forms. It also claims that the use of force constitutes a

Nicholas Tsagourias

146

Force and Its Representation  

NSDL National Science Digital Library

This page is from a comprehensive and comprehensible tutorial in physics. Schematic drawings, animations, and links to animations are included. Use the link in the left navigation bar to explore the related topic of types of forces including frictional force, gravitational force, and magnetic force.

2010-01-01

147

Van der Waals Forces  

Microsoft Academic Search

The last few years have seen tremendous advances in our understanding of van der Waals forces. In this article we shall first survey the common types of forces that exist between atoms and molecules, and then concentrate on van der Wads forces. These forces are always present, so that they play a role in a host of different phenomena (for

Jacob N. Israelachvili

1974-01-01

148

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

149

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

150

INTERNATIONAL COUNCIL FOR  

E-print Network

. Forcing data for 20th and 21st century at PCMDI 4.2 G. Hegerl will contact IADG regarding 20th centuryINTERNATIONAL COUNCIL FOR SCIENCE INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION WORLD METEOROLOGICAL ORGANIZATION WORLD CLIMATE RESEARCH PROGRAMME JSC/CLIVAR Working Group on Coupled Modelling Report of the 7th

Quartly, Graham

151

75 FR 34438 - Defense Science Board Task Force on Trends and Implications of Climate Change for National and...  

Federal Register 2010, 2011, 2012, 2013

...Science Board Task Force on Trends and Implications of Climate Change for National and International Security AGENCY: Department...Science Board Task Force on Trends and Implications of Climate Change for National and International Security will meet...

2010-06-17

152

75 FR 43944 - Defense Science Board; Task Force on Trends and Implications of Climate Change for National and...  

Federal Register 2010, 2011, 2012, 2013

...Science Board; Task Force on Trends and Implications of Climate Change for National and International Security AGENCY: Department...Science Board Task Force on Trends and Implications of Climate Change for National and International Security will meet...

2010-07-27

153

Common Force Field Thermodynamics of Cholesterol  

PubMed Central

Four different force fields are examined for dynamic characteristics using cholesterol as a case study. The extent to which various types of internal degrees of freedom become thermodynamically relevant is evaluated by means of principal component analysis. More complex degrees of freedom (angle bending, dihedral rotations) show a trend towards force field independence. Moreover, charge assignments for membrane-embedded compounds are revealed to be critical with significant impact on biological reasoning. PMID:24302856

Giangreco, Francesco; Yamamoto, Eiji; Hirano, Yoshinori; di Giosia, Matteo; Zerbetto, Francesco; Yasuoka, Kenji; Narumi, Tetsu; Yasui, Masato; Hofinger, Siegfried

2013-01-01

154

International and Cosmopolitan Political Obligations  

Microsoft Academic Search

Over the last few years, there has been intense political debate concerning the rightful use of coercion in the international\\u000a sphere. Strong political forces have maintained that in addition to being inefficient, the current international authority,\\u000a the United Nations (UN), is neither necessary nor desirable for the realization of international justice. This is seen not\\u000a only in how recent efforts

Helga Varden

155

Three-nucleon forces  

NASA Astrophysics Data System (ADS)

In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces.

Sauer, Peter U.

2014-08-01

156

Deployed Force Waste Management.  

National Technical Information Service (NTIS)

This report examines a range of science and technology issues concerning waste management for deployed land forces. Within this waste management context, the report outlines the functional requirements of a deployed force, the status of Australian researc...

S. Baker, B. Vandepeer

2004-01-01

157

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

158

The Centripetal Force Requirement  

NSDL National Science Digital Library

This webpage discusses the role of centripetal acceleration and centripetal force. The site also provides an animation to show how circular motion requires an inward force. Links to related concepts are provided.

2007-07-27

159

Fluid force transducer  

DOEpatents

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

Jendrzejczyk, Joseph A. (Warrenville, IL)

1982-01-01

160

Microprocessor controlled force actuator  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

161

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

162

Turkish Students' Force Meanings  

ERIC Educational Resources Information Center

What are Turkish pre, elementary, middle, and high school students' force ideas? And, how do Turkish students' non-normative force ideas differ or be similar to the well-known force misconceptions reported in the literature? Students have false and persistent beliefs about the physical world and they struggle with challenging misconceptions based…

Menekse, Muhsin; Clark, Douglas B.; Ozdemir, Gokhan; D'angelo, Cynthia; Scheligh, Sharon

2009-01-01

163

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

164

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

165

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.

Christian, Wolfgang; Belloni, Mario

2006-01-13

166

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

167

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

168

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

169

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

170

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

171

Ventromedial Prefrontal Cortex Lesions and Motivational Internalism  

Microsoft Academic Search

This article discusses the argument by Roskies to the effect that ventromedial prefrontal cortex (VMPFC) patients are a living counterexample to motivational internalism. Motivational internalism is a philosophical position according to which moral judgments are accompanied by a particular motivational force that induces agents to act accordingly. Roskies takes into account a very strong version of motivational internalism and claims

Tommaso Bruni

2012-01-01

172

International Consulting.  

ERIC Educational Resources Information Center

Four main areas are identified for the instructional technology consultant to approach the international marketplace: international organizations, the United States government, industry, and international public service organizations. Types of preparation needed, as well as special problems and rewards of international consulting, are discussed.…

Titus, Amy A.; Austin, John H.

1980-01-01

173

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

174

Debunking Coriolis Force Myths  

NASA Astrophysics Data System (ADS)

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

Shakur, Asif

2014-11-01

175

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

176

In-plane video force microscopy of morphogenesis in epithelia  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

177

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

178

International Cooperation at NASA  

NASA Astrophysics Data System (ADS)

International cooperation is a cornerstone principle of NASA’s activities, especially within the activities of the Science Mission Directorate. Nearly two thirds of the flight missions in which NASA leads or participates involve international cooperation. Numerous ground based activities also rely on international cooperation, whether because of unique expertise, unique geography, or the need for a global response. Going forward, in an era of tighter budgets and a more integrated global perspective, NASA and the rest of the space agencies around the world will be forced to work more closely together, in a broader array of activities than ever before, in order to be able to afford to push the boundaries of space exploration. The goal of this presentation is to provide an overview of NASA’s current international science cooperative activities. It will include a discussion of why NASA conducts international cooperation and look at the mechanisms through which international cooperation can occur at NASA, including peer-to-peer development of relationships. It will also discuss some of the limiting factors of international cooperation, such as export control, and ways in which to manage those constraints. Finally, the presentation would look at some of the present examples where NASA is working to increase international cooperation and improve coordination. Case studies will be used to demonstrate these mechanisms and concepts. For example, NASA continues to participate in international coordination groups such as the International Mars Exploration Working Group (IMEWG) and International Space Exploration Coordination Group (ISECG), but is expanding into new areas as well. NASA is one of the leaders in expanding and improving international coordination in the area of Near-Earth Object detection, characterization, and mitigation. Having participated in the first meetings of such groups as the International Asteroid Warning Network (IAWN) and Space Missions Planning Advisory Group (SMPAG), NASA is placing an ever greater emphasis on sharing information among members and working to avoid duplication of effort for the betterment of all humanity. International cooperation at NASA takes many forms. In some cases NASA leads, while in other cases it follows the lead of our many international partners, all in the name of obtaining the best science. In many cases, truly stellar partnerships emerge. In a few cases, the partnership is ended before it can flourish. But in all cases, the partners are learning to work more closely together so that in the future, our partnerships will yield ever better results.

Tawney, Timothy; Feldstein, Karen

179

Direct measurement of critical Casimir forces.  

PubMed

When fluctuating fields are confined between two surfaces, long-range forces arise. A famous example is the quantum-electrodynamical Casimir force that results from zero-point vacuum fluctuations confined between two conducting metal plates. A thermodynamic analogue is the critical Casimir force: it acts between surfaces immersed in a binary liquid mixture close to its critical point and arises from the confinement of concentration fluctuations within the thin film of fluid separating the surfaces. So far, all experimental evidence for the existence of this effect has been indirect. Here we report the direct measurement of critical Casimir force between a single colloidal sphere and a flat silica surface immersed in a mixture of water and 2,6-lutidine near its critical point. We use total internal reflection microscopy to determine in situ the forces between the sphere and the surface, with femtonewton resolution. Depending on whether the adsorption preferences of the sphere and the surface for water and 2,6-lutidine are identical or opposite, we measure attractive and repulsive forces, respectively, that agree quantitatively with theoretical predictions and exhibit exquisite dependence on the temperature of the system. We expect that these features of critical Casimir forces may result in novel uses of colloids as model systems. PMID:18185584

Hertlein, C; Helden, L; Gambassi, A; Dietrich, S; Bechinger, C

2008-01-10

180

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

181

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

182

Van der Waals forces  

Microsoft Academic Search

Van der Waals forces are among the forces that attract atoms and molecules together. Their importance follows from two unique properties. Firstly, they are universal. All atoms and molecules attract one another through this mechanism, so they account for phenomena, such as the cohesion of the inert gases in the solid and liquid states, and physical adsorption of molecules to

R. H. S. Winterton

1970-01-01

183

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

184

NTNU Java: Frictional force  

NSDL National Science Digital Library

This applet illustrates the effect of frictional forces on the motion of masses. In this experiment, two masses, resting one on top of the other, are pulled by a hanging mass connected by an ideal rope. Masses and friction can be changed. Different force vectors are color-coded.

Hwang, Fu-Kwun

2004-12-18

185

Nanofluids mediating surface forces.  

PubMed

Fluids containing nanostructures, known as nanofluids, are increasingly found in a wide array of applications due to their unique physical properties as compared with their base fluids and larger colloidal suspensions. With several tuneable parameters such as the size, shape and surface chemistry of nanostructures, as well as numerous base fluids available, nanofluids also offer a new paradigm for mediating surface forces. Other properties such as local surface plasmon resonance and size dependent magnetism of nanostructures also present novel mechanisms for imparting tuneable surface interactions. However, our fundamental understanding, experimentally and theoretically, of how these parameters might affect surface forces remains incomplete. Here we review recent results on equilibrium and dynamic surface forces between macroscopic surfaces in nanofluids, highlighting the overriding trends in the correlation between the physical parameters that characterise nanofluids and the surface forces they mediate. We also discuss the challenges that confront existing surface force knowledge as a result of this new paradigm. PMID:22795777

Pilkington, Georgia A; Briscoe, Wuge H

2012-11-01

186

ENGINEERING INTERNATIONAL  

E-print Network

COURSE GUIDE 2013 UTS: ENGINEERING INTERNATIONAL UNDERGRADUATE w w w.eng.uts.edu.au #12;2 / ENGINEERING IN AUSTRALIA Internationally, Australian universities have a reputation for high quality research developed close links with many international institutions, particularly in Asia. ENGINEERING IN SYDNEY

University of Technology, Sydney

187

International Opportunities.  

E-print Network

collaborative in nature and global in scope. Enhance international reputation of Section/Faculty/University · enhance the international reputation of the University and/or Faculty · consolidate or initiate-Palacio International Office 23 June 2011 #12;University Strategy · As a University community we will change the world

Anderson, Jim

188

Force networks and elasticity in granular silos.  

PubMed

We have made experimental observations of the force networks within a two-dimensional granular silo similar to the classical system of Janssen. Models like that of Janssen predict that pressure within a silo saturates with depth as the result of vertical forces being redirected to the walls of the silo where they can then be carried by friction. We use photoelastic particles to obtain information not available in previous silo experiments --the internal force structure. We directly compare various predictions with the results obtained by averaging ensembles of experimentally obtained force networks. We identify several differences between the mean behavior in our system and that predicted by Janssen-like models: We find that the redirection parameter describing how the force network transfers vertical forces to the walls varies with depth. We find that changes in the preparation of the material can cause the pressure within the silo to either saturate or to continue building with depth. Most strikingly, we observe a nonlinear response to overloads applied to the top of the material in the silo. For larger overloads we observe the previously reported "giant overshoot" effect where overload pressure decays only after an initial increase (G. Ovarlez et al., Phys. Rev. E 67, 060302(R) (2003)). For smaller overloads we find that additional pressure propagates to great depth. Analysis of the differences between the inter-grain contact and force networks suggests that, for our system, when the load and the particle weight are comparable, particle elasticity acts to stabilize the force network, allowing deep propagation. For larger loads, the force network rearranges, resulting in the expected, Janssen-like behavior. Thus, a meso-scale network phenomenon results in an observable nonlinearity in the mean pressure profile. PMID:20582447

Wambaugh, J F; Hartley, R R; Behringer, R P

2010-06-01

189

International Terrorism in South Asia  

Microsoft Academic Search

This report reviews the international terrorist environment in South Asia, concentrating on Afghanistan, Pakistan, and India.1 With U.S.-led counterterrorism efforts focused especially on Southwest Asia, the existence of international terrorist groups and their supporters in South Asia is identified as a threat to both regional stability and to the attainment of key U.S. policy goals. Al Qaeda forces that fled

K. Alan Kronstadt

190

OOTW Force Design Tools  

SciTech Connect

This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

Bell, R.E.; Hartley, D.S.III; Packard, S.L.

1999-05-01

191

MU INTERNATIONAL DIRECTORY International Directory  

E-print Network

-2170 International Teaching Assistant Program http://pet.missouri.edu/ita/ita.htm 882-6260 International Women://international.missouri.edu/directory/ . Administration Admissions Graduate Admissions http://gradschool.missouri.edu 882-6311 Intensive English Program Association http://www.students.missouri.edu/~romsa/html/english.html South Asian Students Association http

Taylor, Jerry

192

Proliferation of small nuclear forces. Technical report  

SciTech Connect

The objective of this study is to identify and assess the implications of the proliferation of nuclear forces in the Middle East and South Asia for U.S. security interests, policies, and planning. To fulfill this objective, this study seeks to: 1) Project the potential size and capabilities of local nuclear forces, and define the spectrum of threats that such forces could pose to the security interests of the U.S. and of other important actors, both in this region and elsewhere; 2) Assess the probable impact of proliferating nuclear forces on international stability, military balances, the character of conflict, arms control issues, conventional arms competition and U.S. forces; 3) Assess how new nuclear powers will behave and how their neighbors and other nuclear powers will react; 4) Assess Soviet perception and response; 5) Identify the likely patterns and outcomes of nuclear and other military interaction, including perceptions, use of leverage, employment of force, conflict escalation, nuclear warfare, and crisis management, within and beyond the region of concern; 6) Discuss the implications for U.S. defense policy and planning, indicating areas in which future preparation or decisions may be called for.

Jones, R.W.

1983-04-30

193

Quantized Casimir force.  

PubMed

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

Tse, Wang-Kong; MacDonald, A H

2012-12-01

194

Motion and Forces  

NSDL National Science Digital Library

This self-contained module on motion and forces includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Science, Houghton M.

195

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

196

Relativistic linear restoring force  

NASA Astrophysics Data System (ADS)

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: dp/dt or dp/d?. Either formulation recovers Hooke’s law in the non-relativistic limit. In addition to these two forces, we introduce a form of retardation appropriate for the description of a linear (in displacement) force arising from the interaction of a pair of particles with a relativistic field. The procedure is akin to replacing Coulomb’s law in electromagnetism with a retarded form (the first correction in the full relativistic case). This retardation leads to the expected oscillation, but with amplitude growth in both its relativistic and non-relativistic incarnations.

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

2012-09-01

197

Small earthquakes, tectonic forces  

USGS Publications Warehouse

Earthquake scaling and frequency-of-occurrence relations require that small earthquakes be just as important as larger ones in redistributing the forces that drive relative displacements across active faults of any dimension, including plate boundaries.

Hanks, T. C.

1992-01-01

198

Forces Between Cationic Surfactants  

NASA Astrophysics Data System (ADS)

Experiments have been performed on a binary mixture of the liposome forming surfactants, DODAB (cationic) and DOPE (zwitterionic), which are used as DNA transfection agents. Langmuir isotherms were studied at different compositions, salt concentrations, and temperatures. The data was used to calculate the excess free energy of mixing. To further understand the non-ideal interactions, the surface forces apparatus (SFA) was utilised to measure the forces between bilayers, under varying conditions, which expose DODAB in the outer monolayers.

Campbell, Samuel; Meyer, Joan; Park, Chad; Lasic, Dan; Israelachvili, Jacob

1996-03-01

199

Force-Measuring Clamp  

NASA Technical Reports Server (NTRS)

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

Nunnelee, Mark (Inventor)

2004-01-01

200

Strategic Plan Progress Report Berkeley International Office (BIO)  

E-print Network

International Student Enrollment at UC Berkeley Past 10Years #12;BerkeleyInternationalOffice (BIO) Total Experience by supporting students' distinct academic, personal, and social needs. #12;BerkeleyInternational. Billing & Payment Services 9. Campus-wide First Year Experience and International Student Task Forces 10

Jacobs, Lucia

201

The missing climate forcing  

PubMed Central

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.

1997-01-01

202

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

203

Optical Bernoulli forces  

NASA Astrophysics Data System (ADS)

By Bernoulli's law, an increase in the relative speed of a fluid around a body is accompanied by a decrease in the pressure. Therefore, a rotating body in a fluid stream experiences a force perpendicular to the motion of the fluid because of the unequal relative speed of the fluid across its surface. It is well known that light has a constant speed irrespective of the relative motion. Does a rotating body immersed in a stream of photons experience a Bernoulli-like force? We show that, indeed, a rotating dielectric cylinder experiences such a lateral force from an electromagnetic wave. In fact, the sign of the lateral force is the same as that of the fluid-mechanical analog as long as the electric susceptibility is positive (?>?0), but for negative-susceptibility materials (e.g., metals) we show that the lateral force is in the opposite direction. Because these results are derived from a classical electromagnetic scattering problem, Mie-resonance enhancements that occur in other scattering phenomena also enhance the lateral force.

Movassagh, Ramis; Johnson, Steven G.

2013-08-01

204

Weak nuclear forces cause the strong nuclear force  

E-print Network

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 nuclear lattices. The strong force is then about ten to the power of 6 times stronger than the weak force between two lattice points.

E. L. Koschmieder

2007-12-11

205

Future trends in international migration to Europe.  

PubMed

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

Verhaeren, R

1993-01-01

206

International social development and counter-development  

Microsoft Academic Search

International development theory and practice tend to emphasize the importance of optimizing development inputs such as capital, infrastructure, and expertise. Equally important in the success of development is the mitigation of counter-development forces such as corruption, rent-seeking, terrorism and organized crime. This article presents a development model that incorporates those forces that impede development.

Mark Lusk

2010-01-01

207

Gender Ideologies as Complex Social Forces  

Microsoft Academic Search

\\u000a To say that gendered social relations are complex would be to profoundly understate the dynamism of the human experience.\\u000a The ways in which individuals understand their roles as gendered beings and their relationships to other gendered beings is\\u000a constantly pushed and pulled by forces both internal and external to the individual and the family\\/social\\/economic unit to\\u000a which they belong at

Deborah Rotman

208

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

209

International migration within Latin America  

E-print Network

: © IADB Remittances: The Human Face of Globalization #12;Remittances ­ a major consequence of migrationInternational migration within Latin America ·Mostly labor circulation flows ·Industrial and urban migrations 10s of thousands of Iberians Forced migration of ~10 m Africans · 19th century migrations

Lopez-Carr, David

210

Governing International Education in Australia  

ERIC Educational Resources Information Center

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

Sidhu, Ravinder

2004-01-01

211

Japanese Internment  

NSDL National Science Digital Library

Students will examine the decision to place all Japanese-Americans living on the West Coast into internment camps during WWII. This lesson is part of a mini-unit on Japanese Internment that will include readings in primary source documents and materials from History Alive that will provide most of the background knowledge necessary to evaluate the decision to intern Japanese-Americans during the war and the effects of internment on this group during the post-war period. This resource includes both a teaching guide and student worksheets.

Lindskog, Tom

2011-09-14

212

Surgical force detection probe  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

213

Iraq's Porous Frontiers, Internal Struggles and Fragile Statehood  

Microsoft Academic Search

As Iraq enters what appears to be a period of relative stability and recovery, more attention is being given to Iraq's international boundaries and ports of entry (POEs). Iraqi and Coalition Force (CF) security forces have been able to progressively improve Iraq's internal security environment and successfully counter Al Qaeda in Iraq (AQI), insurgents, and militia organizations in the urban

Steven Oluic

2009-01-01

214

Restructure forces, enhance security  

SciTech Connect

The Warsaw Pact proposals call not only for far greater reductions than those discussed by the two blocs, but also for qualitative structural changes aimed at strengthening strategic stability. Conventional forces and armaments are reaching a new stage of development. Some of the new weapons' combat characteristics are approaching those of weapons of mass destruction. And it makes conventional forces usable in new, more destructive ways than before. The tendency of offensive and defensive actions and methods to converge must also be taken into consideration. Accordingly, removing or considerably reducing each side's offensive capabilities would lead to establishing more clear-cut distinctions between offensive and defensive military actions. This is essential for providing strategic stability at the conventional force level. 2 refs.

Kokoshin, A.

1988-09-01

215

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

216

Parametrically forced pattern formation.  

PubMed

Pattern formation in a nonlinear damped Mathieu-type partial differential equation defined on one space variable is analyzed. A bifurcation analysis of an averaged equation is performed and compared to full numerical simulations. Parametric resonance leads to periodically varying patterns whose spatial structure is determined by amplitude and detuning of the periodic forcing. At onset, patterns appear subcritically and attractor crowding is observed for large detuning. The evolution of patterns under the increase of the forcing amplitude is studied. It is found that spatially homogeneous and temporally periodic solutions occur for all detuning at a certain amplitude of the forcing. Although the system is dissipative, spatial solitons are found representing domain walls creating a phase jump of the solutions. Qualitative comparisons with experiments in vertically vibrating granular media are made. (c) 2001 American Institute of Physics. PMID:12779440

Armbruster, Dieter; George, Marguerite; Oprea, Iuliana

2001-03-01

217

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

218

International programs  

NASA Technical Reports Server (NTRS)

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

1973-01-01

219

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

220

Biophysical analysis of swimming force by Chlamydomonas flagella  

NASA Astrophysics Data System (ADS)

Numerous studies have used indirect techniques to investigate the function of flagella of the unicellular green algae Chlamydomonas reinhardtii. We report the first direct measurement of the flagellar swimming force of Chlamydomonas. Using an optical trap we detect a 75% decrease in swimming force between wild type cells and mutant cells lacking an internal flagellar component. This difference is consistent with previous estimates. To examine flagellar organization and function, we deflagellated cells and examined force generation during flagellar regrowth. As expected, fully regrown flagella are functionally equivalent to flagella of untreated wild type cells. However, analysis of swimming force vs. flagella length reveals intriguing patterns where increases in force do not always correspond with increases in length. These investigations of flagellar force contribute to the understanding of Chlamydomonas motility and demonstrate the advantages of the optical trapping technique in studies of cell motility.

Yukich, John N.; Bernd, Karen K.; Patton McCord, Rachel

2005-11-01

221

Forcing Adjoints and Forcing Singular Vectors for Atmospheric Winter Circulations  

Microsoft Academic Search

Perturbations of atmospheric initial conditions grow due to unstable dynamics. Likewise perturbed atmospheric forcing causes growing state perturbations. To the extent that forcing perturbations do not change the nature of the instabilities, the excited growth should be similar to growth of initial perturbations. Forcing perturbations may be model errors or prescribed external forcing. The nature of model errors is not

T. Iversen; J. Barkmeijer; T. N. Palmer

2003-01-01

222

Van der Waals and capacitive forces in atomic force microscopies  

Microsoft Academic Search

In this article we show that in the atomic force microscopy experiments performed on a metallic surface, there is always a long range electrostatic force in addition to the van der Waals forces. This capacitive force is due to the contact potential between the tip and the surface and exists even without external applied potential. We have calculated this capacitive

M. Saint Jean; S. Hudlet; C. Guthmann; J. Berger

1999-01-01

223

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

224

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

225

Police use of force and the cumulative force factor  

Microsoft Academic Search

Purpose – This paper aims to build on and contribute to earlier studies on use of force by the police, and examines both officer and suspect force levels during altercations. Design\\/methodology\\/approach – Prior attempts to study non-lethal force have only recently begun to examine the multiple levels of force that may be used within a single encounter, advocating the use

Ross Wolf; Charlie Mesloh; Mark Henych; L. Frank Thompson

2009-01-01

226

Optical force stamping lithography  

PubMed Central

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

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

2013-01-01

227

Dynamically Forced Fog  

NSDL National Science Digital Library

Fog frequently forms in response to dynamically forced changes in the boundary layer. This module examines dynamically forced fog in the coastal and marine environment, focusing on advection fog, steam fog, and west coast type fog. The focus of the module is on the boundary layer evolution of air parcels as they traverse trajectories over land and water. The module also examines mesoscale effects that impact the distribution of fog and low-level stratus over short distances. A general discussion of forecast products and methodologies concludes the module.

Comet

2005-03-01

228

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

229

China's energy security: Domestic and international issues  

Microsoft Academic Search

Runaway growth in energy consumption poses a real threat to China's energy security. The era of Chinese energy independence is gone, along with the ide- ology of self-reliance as a viable guide for energy policymaking. In particular, China's thirst for oil forces Beijing to aggressively pursue international sources of supply, driving up international oil prices. High oil prices not only

Zha Daojiong

2006-01-01

230

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

231

Forced response of a laminar shock-induced separation bubble  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

232

International Office Head of International Office  

E-print Network

recruitment and support, and to the development of international strategic alliances. The International Office the University's commitment to international students and linkages and international student recruitment will develop an international student recruitment strategy, informed by research and current trends

Humphrys, Mark

233

The Dynamic Force Table  

ERIC Educational Resources Information Center

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

Geddes, John B.; Black, Kelly

2008-01-01

234

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

235

``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

236

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.

237

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.

238

Longitudinal magnet forces?  

NASA Astrophysics Data System (ADS)

The Ampere electrodynamics of metallic conductors and experiments supporting it predict that the interaction of a current-carrying wire with its own magnetic field should produce longitudinal mechanical forces in the conductor, existing in addition to the transverse Lorentz forces. The longitudinal forces should stretch the conductor and have been referred to as Ampere tension. In 1964 it was discovered that a current pulse would break a straight copper wire into many fragments without visible melting. A metallurgical examination of the pieces confirmed that the metal parted in the solid state. The same observation has now been made with aluminum wires. In the latest experiments the wire was bent into a semicircle and arc-connected to a capacitor discharge circuit. The arc connections ruled out rupture by Lorentz hoop tension and indicated the longitudinal forces may also arise in circular magnet windings. Explanations of wire fragmentation by thermal shock, longitudinal stress waves, Lorentz pinch-off, bending stresses, and material defects have been considered and found unconvincing. Computed Ampere tensions would be sufficient to fracture hot wires. The Ampere tension would double the hoop tension normally expected in dipole magnets. This should be borne in mind in the design of large dipole magnets contemplated for MHD power generators and railgun accelerators.

Graneau, P.

1984-03-01

239

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

240

Coordination of Contact Forces During Multifinger Static Prehension  

PubMed Central

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

Martin, Joel R.; Latash, Mark L.

2011-01-01

241

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

242

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...

243

Permeability of continental crust influenced by internal and external forcing  

E-print Network

of advective solute transport (requiring k > $10)20 m2 under normal crustal conditions), advective heat words: geothermal, groundwater, metamorphic, numerical modeling, permeability Received 25 January 2008­139 INTRODUCTION Permeability (k) is a measure of the relative ease of fluid flow under unequal pressure

244

Object motiondecoupled internal force control for a compliant multifingered hand  

E-print Network

Italiano di Tecnologia, Genova, Italy prattichizzo@dii.unisi.it M. Malvezzi and M. Aggravi are with Department of Information Engineering, University of Siena, Italy malvezzi@dii.unisi.it, aggravi@dii.unisi

Siena, Università di

245

Forced convective heat transfer in channels with internal longitudinal fins  

E-print Network

Dh/u (3. 6) In Equations (3. 5) and (3. 6), Dh is the hydraulic diameter and is defined as Dh = 4Af/Pw~ (3. 7) where Af is the flow cross sectional area and P is the wetted perimeter, respectively. Thus, Dh ? 2 D(SLF)/(S+L) for L ( 1, (3. 8) and 12...Dh/u (3. 6) In Equations (3. 5) and (3. 6), Dh is the hydraulic diameter and is defined as Dh = 4Af/Pw~ (3. 7) where Af is the flow cross sectional area and P is the wetted perimeter, respectively. Thus, Dh ? 2 D(SLF)/(S+L) for L ( 1, (3. 8) and 12...

Ong, Liang Eng

2012-06-07

246

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

247

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.

248

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.

249

doi:10.1093/brain/awl070 Brain (2006), 129, 14151425 Impaired anticipatory control of fingertip forces in  

E-print Network

; internal model; grasp; interlimb transfer Abbreviations: CP = cerebral palsy; GFL = grip force at lift. Studies indicate that upper-extremity weakness, spasticity, and abnormal motor synergies are insufficient

250

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

251

The van der Waals force and gravitational force in matter  

E-print Network

It was thought that the van der Waals force and gravitational force were distinct. Now a model is used to describe the attraction between macroscopic objects according to van der Waals interaction. The force between two objects with thermal equilibrium deviates from the law of universal gravitation slightly, and the gravity on the earth is explained approximately. We argue that the gravitational force is the van der Waals force actually. In other words, the gravitational force and mass are related to the quantum fluctuations of electron clouds in atoms, and these parameters are dictated by dielectric susceptibility.

Lei Zhang

2013-03-14

252

The van der Waals force and gravitational force in matter  

E-print Network

It was thought that the van der Waals force and gravitational force were distinct. Now a model is used to describe the attraction between macroscopic objects according to van der Waals interaction. The force between two objects with thermal equilibrium deviates from the law of universal gravitation slightly, and the gravity on the earth is explained approximately. We argue that the gravitational force is the van der Waals force actually. In other words, the gravitational force and mass are related to the quantum fluctuations of electron clouds in atoms, and these parameters are dictated by dielectric susceptibility.

Zhang, Lei

2013-01-01

253

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 k(s)(f) = ? + ?(f/f¯)(?) (? = 7.6 × 10(-4) N m(-1), ? = 1.0 × 10(-4) N m(-1), f¯ = 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; Mendes Filho, J; Schäpe, J; Doschke, H; Radmacher, M

2014-04-01

254

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

255

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

256

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

257

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

258

Air Force Historical Research Agency  

NSDL National Science Digital Library

This Website from the US Air Force provides a brief description of the overall holdings of the agency, which are comprised of over "70,000,000 pages devoted to the history of the service, and represent the world's largest and most valuable organized collection of documents on US military aviation." The site also supplies detailed descriptions of the personal papers of Air Force members held by the agency and gives bibliographic information on 200 historical studies conducted by the agency on topics of Air Force history. Also included here are a substantive account of Air Force involvement in the Korean War; an online text on Air Force heraldry; detailed descriptions of the Air Force's force structure from 1939 to the present, giving an accounting of the types and quantities of different crafts held by the Force; and more information about Air Force organization and unit history.

259

The task force process  

SciTech Connect

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

Applegate, J.S. [Univ. of Cincinnati, OH (United States)

1995-01-31

260

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

261

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

262

International Mathematics Education  

E-print Network

International Mathematics Education Masters Programme www.uni-bremen.de/international-mathematics-education Professional Development for Mathematics Teachers in International Schools International school mathematics in International Mathematics Education. The programme combines foci in mathematics, education and international

Hoffmeister, Thomas S.

263

International occupational health.  

PubMed

Working conditions for the majority of the world's workers do not meet the minimum standards and guidelines set by international agencies. Occupational health and safety laws cover only about 10 percent of the population in developing countries, omitting many major hazardous industries and occupations. With rare exception, most countries defer to the United Nations the responsibility for international occupational health. The UN's international agencies have had limited success in bringing occupational health to the industrializing countries. The International Labor Organization (ILO) conventions are intended to guide all countries in the promotion of workplace safety and in managing occupational health and safety programs. ILO conventions and recommendations on occupational safety and health are international agreements that have legal force only if they are ratified by ILO member states. The most important ILO Convention on Occupational Safety and Health has been ratified by only 37 of the 175 ILO member states. Only 23 countries have ratified the ILO Employment Injury Benefits Convention that lists occupational diseases for which compensation should be paid. The World Health Organization (WHO) is responsible for the technical aspects of occupational health and safety, the promotion of medical services and hygienic standards. Limited WHO and ILO funding severely impedes the development of international occupational health. The U.S. reliance on international agencies to promote health and safety in the industrializing countries is not nearly adequate. This is particularly true if occupational health continues to be regarded primarily as an academic exercise by the developed countries, and a budgetary triviality by the international agencies. Occupational health is not a goal achievable in isolation. It should be part of a major institutional development that touches and reforms every level of government in an industrializing country. Occupational health and safety should be brought to industrializing countries by a comprehensive consultative program sponsored by the United States and other countries that are willing to share the burden. Occupational health and safety program development is tied to the economic success of the industrializing country and its industries. Only after the development of a successful legal and economic system in an industrializing country is it possible to incorporate a successful program of occupational health and safety. PMID:12971685

LaDou, Joseph

2003-08-01

264

Physical curl forces: dipole dynamics near optical vortices  

NASA Astrophysics Data System (ADS)

The force on a particle with complex electric polarizability is known to be not derivable from a potential, so its curl is non-zero. This ‘curl force’ is studied in detail for motion near an anisotropic optical vortex of arbitrary strength. Fundamental questions are raised by the fact that although the curl force requires the polarizability to have a non-zero imaginary part, reflecting absorption or scattering (‘dissipation’) in the internal dipole dynamics, the particle motion that it generates is non-dissipative (volume-preserving in the position-velocity state space).

Berry, M. V.; Shukla, Pragya

2013-10-01

265

Diamagnetic force on a flux tube  

NASA Technical Reports Server (NTRS)

The diamagnetic force on a straight flux tube is elucidated. The case when the flux tube has a circular cross section is considered, and the result is generalized to the case of noncircular cross section. The result shows that when the external magnetic field is uniform, the diamagnetic force is simply equal to the vector multiplication of the internal conduction current and the external magnetic field. It is independent of the size and shape of the cross section of the flux tube. This is analogous to the Kutta-Joukowski theorem that the aerodynamic lift force is proportional to the vector multiplication of the unperturbed flow velocity and the circulation around the airfoil. When the external magnetic field is nonuniform, the diamagnetic force has an additional contribution which is proportional to the gradient of magnetic pressure and to the volume of the flux tube. The constant of proportionality, which is shown to be equal to two for a circular cross section, indicates the enhancement of the nonuniformity of the external magnetic field in the vicinity of the periphery by the polarization current.

Yeh, T.

1983-01-01

266

Force sensing and mapping by atomic force microscopy  

Microsoft Academic Search

Over the past 15 years, advances in the field of atomic force microscopy (AFM) have broadened its use from a high-resolution imaging instrument to a device capable of detecting and quantifying single molecular forces between surfaces in near-native conditions. This article reviews developments in the force sensing field and focuses particularly on research that has seen the AFM utilised to

Nicola H Green; Stephanie Allen; Martyn C Davies; Clive J Roberts; Saul J. B Tendler; Philip M Williams

2002-01-01

267

Interaction forces between oilwater particle interfaces--Non-DLVO forces  

E-print Network

in the presence of sodium nitrate showed repulsion at all concentrations. Force measurements in the presence that the force­distance data for the sodium nitrate system obeys typical DLVO interactions. The disagreement of the water solubility of the organic liquid, in that the same force­distance characteristics were obtained

Chan, Derek Y C

268

Nonequilibrium Forces Between Neutral Atoms Mediated by a Quantum Field  

E-print Network

We study all known and as yet unknown forces between two neutral atoms, modeled as three dimensional harmonic oscillators, arising from mutual influences mediated by an electromagnetic field but not from their direct interactions. We allow as dynamical variables the center of mass motion of the atom, its internal degrees of freedom and the quantum field treated relativistically. We adopt the method of nonequilibrium quantum field theory which can provide a first principle, systematic and unified description including the intrinsic field fluctuations and induced dipole fluctuations. The inclusion of self-consistent back-actions makes possible a fully dynamical description of these forces valid for general atom motion. In thermal equilibrium we recover the known forces -- London, van der Waals and Casimir-Polder forces -- between neutral atoms in the long-time limit but also discover the existence of two new types of interatomic forces. The first, a `nonequilibrium force', arises when the field and atoms are not in thermal equilibrium, and the second, which we call an `entanglement force', originates from the correlations of the internal degrees of freedom of entangled atoms.

Ryan Orson Behunin; Bei-Lok Hu

2010-02-13

269

Individual Liability of Private Military Personnel under International Criminal Law  

Microsoft Academic Search

The article examines the present status of private military personnel under international criminal law. Perpetrators of international crimes are frequently integrated into a hierarchically structured collective, such as an army or police force. The system of order and obedience essential to the functioning of these entities, the existence of which underlies a number of principles of international criminal law, cannot

Chia Lehnardt

2008-01-01

270

International Education in Systemic Educational Reforms: The Chinese Case and Lessons Learned from an International Perspective  

ERIC Educational Resources Information Center

International research findings and country experiences prove that, in coping with the tension between the global and the local in education, three major forces contribute to the success of international reform: firstly, the national public authorities in protecting education as a common good through political commitment and policy actions;…

Zhou, Nanzhao

2007-01-01

271

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

272

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.

273

Stem Cell Task Force  

NSDL National Science Digital Library

This Web site from the National Institutes of Health (NIH) provides an overview of the activities of an NIH task force established to move the stem cell research agenda forward. The section titled Scientific Research may be of particular interest to researchers in this area. It provides links to the Web sites of stem cell-related research at a number of NIH institutes, as well as an extensive information index, a FAQs page about stem cell research, information on funding opportunities, and much more.

274

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

275

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

276

Forced to Fracture  

NSDL National Science Digital Library

Students learn how forces affect the human skeletal system through fractures and why certain bones are more likely to break than others depending on their design and use in the body. They learn how engineers and doctors collaborate to design effective treatments with consideration for the location, fracture severity and patient age, as well as the use of biocompatible materials. Learning the lesson content prepares students for the associated activity in which they test small animal bones to failure and then design treatment repair plans.

National Science Foundation GK-12 and Research Experience for Teachers (RET) Programs,

277

Atomic Force Microscope  

SciTech Connect

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

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

1988-12-01

278

INTERNATIONAL COMMUNICATION  

E-print Network

TOOLS FOR INTERNATIONAL COMMUNICATION Joan Crowley Laurence Steinman June 24, 2014 #12;What is Communication? #12;What is Communication? - a process by which information is exchanged between individuals with communication is the illusion that it has taken place. � George Bernard Shaw #12;LANGUAGE When communicating

Di Pillo, Gianni

279

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

280

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

281

Electrostatic Force in Blowing Snow  

Microsoft Academic Search

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

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

1999-01-01

282

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

283

Forcing Adjoints and Forcing Singular Vectors for Atmospheric Winter Circulations  

NASA Astrophysics Data System (ADS)

Perturbations of atmospheric initial conditions grow due to unstable dynamics. Likewise perturbed atmospheric forcing causes growing state perturbations. To the extent that forcing perturbations do not change the nature of the instabilities, the excited growth should be similar to growth of initial perturbations. Forcing perturbations may be model errors or prescribed external forcing. The nature of model errors is not known a priori. As for initial conditions, perturbations of forcing terms that excite a maximum state difference in a target domain, after a finite time-span, can be constructed assuming tangent-linearity. Such Forcing Singular Vectors (FSV) can, in principle, be used for constructing probability forecasts. For long-range forecasting and climate projections, model errors and external atmospheric forcing are usually more important than initial atmospheric conditions. It is then important to link occurrence of regional weather regimes with atmospheric forcing mechanisms such as ground-surface fluxes and radiative forcing. "Forcing adjoints" of flow regimes constitute a first guess of such a link. In this presentation we show statistical properties of FSVs and forcing adjoints of NH flow regimes over six winter seasons. A three-level, quasi-geostrophic GCM is used for the atmosphere (Marshall and Molteni, 1993, J. Atmos. Sci., 50, p.1792). FSVs are of larger spatial scale and indicate considerably less remote control than initial condition SVs. The validity of linearity will be discussed.

Iversen, T.; Barkmeijer, J.; Palmer, T. N.

2003-04-01

284

Gradient and scattering forces in photoinduced force microscopy  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

285

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

286

New Developments in International Law  

Microsoft Academic Search

The fate of law is change. Change is the law of nature. Law goes on changing in accordance with the demands of society. International Law(Jus Gentium)does not form any exception to the above truth. The 20th Century has witnessed an ever-accelerating rhythm of change; the scientific and technological developments have unleashed political, economic, social and cultural forces which are transforming

Gholam Ali Nouri Babanari

1990-01-01

287

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

288

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

289

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

290

Forced emigration, favourable outcomes.  

PubMed

The discipline of public health and preventive medicine in Australia and New Zealand had its genesis in the advocacy of 18th and 19th century military pioneers. Military (Royal Navy and British Army) surgeons were posted to Australia as part of their non-discretionary duty. Civilian doctors emigrated variously for adventure, escapism and gold fever. One group, a particularly influential group disproportionate to their numbers, came in one sense as forced emigrants because of chronic respiratory disease in general, and tuberculosis in particular. Tuberculosis was an occupational hazard of 19th century medical and surgical practice throughout western Europe. This paper analyses six examples of such emigration which had, perhaps unforeseen at the time, significant results in the advancement of public health. Such emigration was in one sense voluntary, but in another was forced upon the victims in their quest for personal survival. In Australia, such medical individuals became leading advocates and successful catalysts for change in such diverse fields as social welfare, public health, the preventive aspects of medical practice, child health, nutrition and medical education. A number of such public health pioneers today have no physical memorials; but their influence is to be seen in the ethos of medical practice in Australia and New Zealand today. Their memory is further perpetuated in the names of Australian native wildflowers and trees that symbolise not only a healthy environment but the long-term investment, accrued with interest, of the institution of public health measures for which their advocacy achieved much success. PMID:11688628

Pearn, J

2001-10-01

291

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-Phd Program

292

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

ERIC Educational Resources Information Center

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

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

2014-01-01

293

Parallel computation with the force  

NASA Technical Reports Server (NTRS)

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

Jordan, H. F.

1985-01-01

294

INTERNATIONAL STUDIES 207 INTERNATIONAL CENTER  

E-print Network

as renowned scholars and scientists from around the globe. It's a hub for international programs, centers students and scholars, scientists, and leaders are at work--from the MSU Bioeconomy Institute in western Development www.casid.isp.msu.edu Center for European, Russian, Eurasian Studies www.cers.isp.msu.edu Center

Liu, Taosheng

295

Pressure, Force, Muscles and Massage  

NSDL National Science Digital Library

The human body is constantly being subjected to external forces. The relation between force and pressure is straightforward. The more force exerted, the greater the pressure, but the effect of area on pressure is somewhat more subtle. Through the process of massage students apply their understanding of forces and pressures to enhance the relaxation of their lab partner's forearm. A proper understanding of the concept of pressure is essential to an understanding of most areas of physiology. This activity provides students with a feeling for what pressure is and how it is related to force and area. Students determine the pressure exerted on the bottoms of their feet under a variety of circumstances. In each case, the force exerted is body weight. But the area over which that force is exerted differs, depending on whether one is standing on two feet, one foot or tiptoe (one-foot.)

Kristin Shields (Vanden High School REV)

1995-06-30

296

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

PubMed Central

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

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

2012-01-01

297

Wetlands International  

NSDL National Science Digital Library

Established as a non-governmental organization, Wetlands International is concerned with promoting the conservation and wise use of wetlands on the global, regional, and national levels. Much of the information on the site is contained within a dozen or so sections along the left-hand side of the homepage. First-time visitors may want to read through the "About Us" area before proceeding to the "Introduction to Wetlands" area. Scholars and policy analysts will want to also look through the "Publications" area. Here they will find information sheets on peatland loss, user handbooks on various wetland regions, and related fact sheets for general use. Visitors may also want to peruse the "Biodiversity Programmes" area to learn more about the species and habitats that Wetlands International works to preserve through their advocacy work. The site is rounded out by a collection of recent news stories and press releases.

298

Chin force in violin playing.  

PubMed

Force generated between the left mandible of violinists and the chinrest of the violin was examined using a force-sensing chinrest developed in this study. A strain-gauge force sensor was built, and it was fixed between the violin's top plate and a chin cup. Fifteen professional/amateur violinists held the violin statically, played musical scales with different sound properties and sounding techniques, as well as an excerpt from a Max Bruch concerto. Peak and mean forces were evaluated for each task. In a separate experiment, lateral movement of the lower teeth due to different levels of voluntary chin force exertion was measured. Static holding forces observed were 15 and 22 N with and without the help of the left hand, respectively. Peak force increased from 16 N at soft dynamics to 20 N at strong dynamics during scales. The force further increased to 29 N with the use of vibrato technique and 35 N during shifts. Tempo and hand position did not affect the force. Playing a Bruch concerto induced a mean peak force of 52 N, ranging from 31 to 82 N among the violinists. The developed force-sensing chinrest could accurately record the generated chin force. Typical chin force to stabilize the violin during ordinary musical performance was less than 30 N, but it could momentarily exceed 50 N when technically demanding musical pieces were performed. The lateral shift of the mandible was fairly small (<0.4 mm) even with high chin-force exertion, possibly due to clenching of the molars. PMID:21952980

Obata, Satoshi; Kinoshita, Hiroshi

2012-06-01

299

CONTROL FORCE CHANGE DUE TO ADAPTATON OF FORWARD MODEL IN  

E-print Network

CONTROL FORCE CHANGE DUE TO ADAPTATON OF FORWARD MODEL IN HUMAN MOTOR CONTROL by Tie Wang A thesis of the human motor adaptive controller. The concept of internal model, a system for predicting behavior of the controlled movements, is divided into a forward and an inverse model. The existence and learning ability

Shadmehr, Reza

300

The Impact of Institutional Forces on Software Metrics Programs  

Microsoft Academic Search

Software metrics programs are an important part of a software organization's productivity and quality initiatives as precursors to process-based improvement programs. Like other innovative practices, the implementation of metrics programs is prone to influences from the greater institutional environment the organization exists in. In this paper, we study the influence of both external and internal institutional forces on the assimilation

Anandasivam Gopal; Tridas Mukhopadhyay; Mayuram S. Krishnan

2005-01-01

301

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

302

Deep atomic force microscopy  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

303

Deep atomic force microscopy  

SciTech Connect

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

Barnard, H.; Drake, B.; Randall, C.; Hansma, P. K. [Department of Physics, University of California, Santa Barbara, California 93106 (United States)] [Department of Physics, University of California, Santa Barbara, California 93106 (United States)

2013-12-15

304

[Galileo and centrifugal force].  

PubMed

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

Vilain, Christiane

305

Forced cocurrent smoldering combustion  

NASA Technical Reports Server (NTRS)

An analytical model of cocurrent smoldering combustion through a very porous solid fuel is developed. Smoldering is initiated at the top of a long radially insulated uniform fuel cylinder, so that the smolder wave propagates downward, opposing an upward-forced flow of oxidizer, with the solid fuel and the gaseous oxidizer entering the reaction zone from the same direction (hence, cocurrent). Radiative heat transfer was incorporated using a diffusion approximation, and smoldering was modeled using a one-step reaction mechanism. The results indicate that, for a given fuel, the final temperature depends only on the initial oxygen mass flux, increasing logarithmically with the mass flux. The smolder velocity is linearly dependent on the initial oxygen mass flux, and, at a fixed value of the flux, increases with initial oxygen mass fraction. The mathematical relationship determining the conditions for steady smolder propagation is presented.

Dosanjh, Sudip S.; Pagni, Patrick J.; Fernandez-Pello, A. Carlos

1987-01-01

306

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 8.0 kph and greater on an instrumented treadmill in the lab and on the ISS. Ground-reaction forces in 0G were less than in 1G for a given speed depending upon the gravity-replacement force, but did increase with increased speed and gravity-replacement force. Ground-reaction forces attained in 1G during slower running could be attained by increasing running speed and/or increasing gravity-replacement forces in 0G. Loading rates in 1G, however, could not be replicated in 0G. While current gravity-replacement force devices are limited in load delivery magnitude, we recommend increasing running speeds to increase the mechanical loads applied to the musculoskeletal system during 0G treadmill exercise, and to potentially increase exercise session efficiency. PMID:24835563

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

2014-07-18

307

Direct force balance method for atomic force microscopy lateral force calibration  

SciTech Connect

A new and simple calibration method for atomic force microscopy (AFM) is developed. This nonscanning method is based on direct force balances on surfaces with known slopes. The lateral force calibration is performed during force-distance measurements for normal force calibration. This method requires a substrate with known slopes, the z motion of the piezocalibrated, and the normal spring constant known. This technique determines not only the lateral detector sensitivity (N/V) but also the detector offset (V/m) and off-centering angle ({alpha}) for asymmetric cantilever-tip geometries. Because it is nonscanning, the AFM cantilever can be calibrated without dulling the tip.

Asay, David B.; Kim, Seong H. [Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2006-04-15

308

Nonequilibrium forces between neutral atoms mediated by a quantum field  

SciTech Connect

We study forces between two neutral atoms, modeled as three-dimensional harmonic oscillators, arising from mutual influences mediated by an electromagnetic field but not from their direct interactions. We allow as dynamical variables the center-of-mass motion of the atom, its internal degrees of freedom, and the quantum field treated relativistically. We adopt the method of nonequilibrium quantum field theory which can provide a first-principles, systematic, and unified description including the intrinsic and induced dipole fluctuations. The inclusion of self-consistent back-actions makes possible a fully dynamical description of these forces valid for general atom motion. In thermal equilibrium we recover the known forces--London, van der Waals, and Casimir-Polder--between neutral atoms in the long-time limit. We also reproduce a recently reported force between atoms when the system is out of thermal equilibrium at late times. More noteworthy is the discovery of the existence of a type of (or identification of the source of some known) interatomic force which we call the ''entanglement force,'' originating from the quantum correlations of the internal degrees of freedom of entangled atoms.

Behunin, Ryan O. [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Hu, Bei-Lok [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

2010-08-15

309

Nonlinear dynamics and force spectroscopy in dynamic atomic force microscopy  

Microsoft Academic Search

As one branch of atomic force microscopy (AFM), dynamic atomic force microscopy (Dynamic AFM) uses a resonating probe with frequency (FM-AFM) or amplitude modulation (AM-AFM) to measure sample topography and material properties of nanostructures with nanometer resolution. Under the influence of tip-sample interaction forces, the dynamics of the probe become highly nonlinear and can affect the imaging stability and interaction

Shuiqing Hu

2007-01-01

310

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. PMID:23653192

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

2013-01-01

311

Trends of measured climate forcing agents  

NASA Astrophysics Data System (ADS)

* National Aeronautics and Space Administration, Goddard Institute for Space Studies, New York, NY 10025; and Center for Climate Systems Research, Columbia University Earth Institute, New York, NY 10025 Contributed by James E. Hansen, October 16, 2001 The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/m2 per century. This growth rate has since declined to 3 W/m2 per century, largely because of cooperative international actions. We argue that trends can be reduced to the level needed for the moderate "alternative" climate scenario (?2 W/m2 per century for the next 50 years) by means of concerted actions that have other benefits, but the forcing reductions are not automatic "co-benefits" of actions that slow CO2 emissions. Current trends of climate forcings by aerosols remain very uncertain. Nevertheless, practical constraints on changes in emission levels suggest that global warming at a rate +0.15 ± 0.05°C per decade will occur over the next several decades.

Hansen, James E.; Sato, Makiko

2001-12-01

312

Drag force models for the Stella satellite  

NASA Astrophysics Data System (ADS)

In the kinetic paradigm, the choice of the models of gaz-surface interaction plays a crucial role in the modeling of the drag effects. In this study, we recall the most used model for drag force (from Schamberg - 1959) and we compare it with another classical model (from Afonso - 1985), for the computation of orbital arcs of the Stella satellite over several years. The results obtained are better with the Afonso's model, regarding both computation residuals and estimated empirical coefficients of the drag force. Weekly orbital arcs are computed from SLR data tracked by the ILRS (International Laser Ranging Service) network with the GRGS (French Space Geodesy Research Group) GINS software and several configurations are tested (without estimation of any empiral coefficient for the drag force, estimation of one coefficient per arc, and estimation of coefficients with a six-hour sampling over the arc). Moreover, the study underlines the importance of estimating some parameters that describe the microstructure of the surface of the satellite.

Bernard, Etienne; Coulot, David; Deleflie, Florent; Pollet, Arnaud

313

Complexity International  

NSDL National Science Digital Library

Complexity International (CI) is an electronic journal devoted to "the field of complex systems, the generation of complex behaviour from the interaction of multiple parallel processes." The journal covers a wide variety of topics, including genetic algorithms, neural networks, and chaos theory. Because much of the focus is based on technological imitation of biological processes, some of the papers are closely tied to the life sciences. Volumes are added to on a continual basis as papers are accepted. Due to the lengthy acceptance process, it is especially useful that the CI Web site offers drafts of current submissions.

314

Internationally Common Features of Public Old-Age Pensions, and Their Implications for Models of the Public Sector  

Microsoft Academic Search

What does the international history of old-age Social Security program design say about the forces creating and sustaining it as a public program? First, because many program features are internationally common, and\\/or explained by country characteristics, SS may emerge and grow due to systematic political and economic forces. Second, some observations suggest that political forces are important: (a) SS redistributes

Casey B. Mulligan; Xavier Sala-i-Martin

2004-01-01

315

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

316

From mechanical force to RhoA activation  

PubMed Central

Throughout their lives all cells constantly experience and respond to various mechanical forces. These frequently originate externally but can also arise internally as a result of the contractile actin cytoskeleton. Mechanical forces trigger multiple signaling pathways. Several converge and result in the activation of the GTPase RhoA. In this review we focus on the pathways by which mechanical force leads to RhoA regulation, especially when force is transmitted via cell adhesion molecules that mediate either cell-matrix or cell-cell interactions. We discuss both the upstream signaling events that lead to activation of RhoA, as well as the downstream consequences of this pathway. These include not only cytoskeletal reorganization and, in a positive feedback loop, increased myosin-generated contraction, but also profound effects on gene expression and differentiation. PMID:22931484

Lessey, Elizabeth C.; Guilluy, Christophe; Burridge, Keith

2012-01-01

317

Entropic force and entanglement system  

SciTech Connect

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

Myung, Yun Soo; Kim, Yong-Wan [Institute of Basic Science and School of Computer Aided Science, Inje University, Gimhae 621-749 (Korea, Republic of)

2010-05-15

318

MEMS Bragg grating force sensor.  

PubMed

We present modeling, design, fabrication and characterization of a new type of all-optical frequency modulated MEMS force sensor based on a mechanically amplified double clamped waveguide beam structure with integrated Bragg grating. The sensor is ideally suited for force measurements in harsh environments and for remote and distributed sensing and has a measured sensitivity of -14 nm/N, which is several times higher than what is obtained in conventional fiber Bragg grating force sensors. PMID:21996861

Reck, Kasper; Thomsen, Erik V; Hansen, Ole

2011-09-26

319

The Science of Spring Force  

NSDL National Science Digital Library

Students use data acquisition equipment to learn about force and displacement in regard to simple and complex machines. In the engineering world, materials and systems are tested by applying forces and measuring the resulting displacements. The relationship between the force applied on a material, and its resulting displacement, is a distinct property of the material, which is measured in order to evaluate the material for correct use in structures and machines.

AMPS GK-12 Program,

320

Coriolis Force on Your Arms  

Microsoft Academic Search

The Coriolis force is a sideward force that acts on a rotating object as it moves toward or away from the center of rotation. It is important to long-range artillery and the formation of tornados, but we seldom experience this force on a human scale, unless we play on a merry-go-round or similar apparatus.1 This note describes a simple activity

Robert Johns

2003-01-01

321

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. PMID:24883335

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

2014-01-01

322

Transparency International  

NSDL National Science Digital Library

With headquarters in Berlin, Transparency International (TI) is an international non-governmental organization dedicated to combating corruption in its many guises across the world. As their website notes, TI âÂÂfocuses on prevention and reforming systemsâÂÂ. With a well-designed and rather elegant homepage, visitors will find much to admire here. The top of the homepage provides access to their âÂÂIn Focusâ feature, which draws attention to some of TIâÂÂs more recent work, such as the Global Corruption Report for 2006. Below this feature, visitors will find links to recent news stories dealing with corruption, such as the recent Kenyan government scandal and anti-corruption initiatives in West Africa. Visitors can also utilize the âÂÂCorruption: Learn About itâ area, as it contains FAQs on corruption, and a number of indices, such as the global corruption barometer as well as a number of regional surveys. For pragmatic material, one need to look no further than their âÂÂHow to Fight Corruptionâ section, which contains an anti-corruption handbook and a set of business principles for countering bribery.

323

Force As A Momentum Current  

SciTech Connect

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

Munera, Hector A. [International Center for Physics (CIF, Centro Internacional de Fisica), Apartado 4948, Bogota (Colombia)

2010-07-28

324

Curvature force and dark energy  

E-print Network

A curvature self-interaction of the cosmic gas is shown to mimic a cosmological constant or other forms of dark energy, such as a rolling tachyon condensate or a Chaplygin gas. Any given Hubble rate and deceleration parameter can be traced back to the action of an effective curvature force on the gas particles. This force self-consistently reacts back on the cosmological dynamics. The links between an imperfect fluid description, a kinetic description with effective antifriction forces, and curvature forces, which represent a non-minimal coupling of gravity to matter, are established.

Alexander B. Balakin; Diego Pavon; Dominik J. Schwarz; Winfried Zimdahl

2003-02-07

325

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

326

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

327

Modeling and estimation of internal friction in cloth  

E-print Network

Force-deformation measurements of cloth exhibit significant hysteresis, and many researchers have identified internal friction as the source of this effect. However, it has not been incorporated into computer animation ...

Miguel, Eder

328

22 CFR 130.3 - Armed forces.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force,...

2011-04-01

329

22 CFR 130.3 - Armed forces.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Armed forces. 130.3 Section 130.3 Foreign Relations...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.3 Armed forces. Armed forces means the army, navy, marine, air force,...

2010-04-01

330

Domestic Constraints and International Forces: Exploring China's Position on International Climate Change Policy  

Microsoft Academic Search

China can be characterized as the key actor in solving the global climate change problem because of the size of its GHG-emissions. Currently it is the second largest emitter of gases causing global warming after the United States. In addition, China has a big influence in climate change negotiations due to its position in the Group of 77 states (G77).

Yang Yi

331

Adding Value to Force Diagrams: Representing Relative Force Magnitudes  

ERIC Educational Resources Information Center

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

Wendel, Paul

2011-01-01

332

The International Psychogeriatric Association Eleventh International Congress  

E-print Network

and Opportunities for the Aging http://abstract.confex.com/ipa/11congress/ PRESENTATION New Technology and NewThe International Psychogeriatric Association Eleventh International Congress Chicago, United

333

Does an instrumented treadmill correctly measure the ground reaction forces?  

PubMed Central

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

Willems, Patrick A.; Gosseye, Thierry P.

2013-01-01

334

Examining the Impact of External Influences on Police Use of Deadly Force over Time.  

ERIC Educational Resources Information Center

Used interrupted time-series analysis (ARIMA) to study the impact of legislation and judicial intervention on the use of deadly force by police officers in Philadelphia, Pennsylvania. Findings generally suggest that dynamic changes in the internal working environment can outweigh the influence of external mechanisms on deadly force use. Findings…

White, Michael D.

2002-01-01

335

The Security Council's Crisis of Legitimacy and the Use of Force  

Microsoft Academic Search

The United Nations Security Council (UNSC) occupies a unique position in the regime governing the use of force in international politics. Two key principles underpin this regime: first, a ban on the individual use of force other than for purposes of self-defence (in the face of actual or imminent attack); and second, it is the responsibility of the UNSC to

Justin Morris; Nicholas J Wheeler

2007-01-01

336

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...

337

Quarks and the Strong Force Summary/Review Spring 2009 Compton Lecture Series  

E-print Network

the strong force to grow with distance , holding colored objects together as if by a spring ­ Unlike and neutrons carry no net color, but they do have internal color structure. Like atoms or molecules which, the protons and neutrons stick together. The force decreases rapidly with distance because as you get further

338

Probabilistic Estimates of Transient Climate Sensitivity Subject to Uncertainty in Forcing and Natural Variability  

E-print Network

Probabilistic Estimates of Transient Climate Sensitivity Subject to Uncertainty in Forcing of uncertainty on estimates of transient climate sensitivity (TCS) of the globally averaged surface temperature, including both uncertainty in past forcing and internal variability in the climate record. This study

Vallis, Geoff

339

Efficient formulation of the force-distribution equations for simple closed-chain robotic mechanisms  

Microsoft Academic Search

Force distribution is the inverse dynamics problem for multiple-chain systems in which the motion is completely specified and the internal forces\\/torques to effect this motion are to be determined. A computationally efficient formulation for the force-distribution problem is presented. This formulation is applicable to a number of simple closed-chain robotic mechanisms, including dexterous hands, multiple manipulators, and multilegged vehicles. Modeling

Fan-Tien Cheng; David E. Orin

1991-01-01

340

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

341

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.

342

Incipient Sediment Movement by Shoaling Internal Gravity Waves  

Microsoft Academic Search

criterion for incipient movement of bottom sediment by shoaling internal waves by equating moments due to fluid force and gravity force acting on an exposed bed particle. Comparison of predicted conditions of incipient sediment movement with mean sediment sizes actually present on the continental shelf and continental slope southeast of New England indicates that shoreward propagation of relatively high frequency

D. A. Cacchione; J. B. Southard

1974-01-01

343

Language Learning in International Schools: Has This Become a Business?  

Microsoft Academic Search

International schools are unique as they have grown into a dynamic educational force both locally and globally in recent decades. These schools originally started in the early 1900s to serve children of armed forces personnel and diplomats overseas. Teachers were initially recruited from amongst the available transient parent body to provide an education similar to that which the students would

Lalima Jenckes

344

Curvature force and dark energy  

Microsoft Academic Search

A curvature self-interaction of the cosmic gas is shown to mimic a cosmological constant or other forms of dark energy, such as a rolling tachyon condensate or a Chaplygin gas. Any given Hubble rate and deceleration parameter can be traced back to the action of an effective curvature force on the gas particles. This force self-consistently reacts back on the

Alexander B. Balakin; Diego Pavón; Dominik J Schwarz; Winfried Zimdahl

2003-01-01

345

How Does Force Affect Motion?  

ERIC Educational Resources Information Center

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

Darling, Gerald

2012-01-01

346

Unsteady forces on spherical bubbles  

Microsoft Academic Search

An experimental investigation of freely rising spherical bubbles through a quiescent liquid is presented. The objective of the experiments is to examine the validity of a recently proposed history force expression for clean, spherical bubbles at finite Reynolds number (Mei et al. 1994). Excellent agreement between the measured and predicted bubble trajectory is obtained when using the proposed history force

W. C. Park; J. F. Klausner; R. Mei

1995-01-01

347

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

348

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

349

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

350

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

351

How Kinetochores CCAN Resist Force.  

PubMed

Kinetochores orchestrate chromosome segregation during mitosis and must cope with dynamic forces generated by attached microtubules. In this issue of Developmental Cell, Suzuki et al. (2014) demonstrate that the constitutive centromere-associated network (CCAN) displays a complex architecture that plays a crucial role in resisting these forces. PMID:25268168

McAinsh, Andrew D

2014-09-29

352

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

353

Coulomb force virtual space structures  

Microsoft Academic Search

Recently, several uses for intercraft Coulomb forces have been explored. Proposed applications have ranged from creating static formations of many spacecraft to steerable nanosat deployment systems. This paper considers the use of Coulomb forces for creating space structures. Unlike conventional space structures, these \\

Gordon Parker; Hanspeter Schaub; Arun Natarajan; Lyon King

2006-01-01

354

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

355

Ecosystem Task Force Meeting Minutes  

E-print Network

Ecosystem Task Force Meeting Minutes Date: April 28, 2011 Title of Meeting: Monthly Meeting. A focus on planning helps ground the Task Force because of the complexity of ecosystems. UNH-862-0785 sustainability.info@unh.edu http://www.sustainableunh.unh.edu/ #12;3.1. Ecosystem work has no defined parameters

New Hampshire, University of

356

Service Excellence Task Force Report.  

ERIC Educational Resources Information Center

A task force was appointed to measure user satisfaction with library services, establish a university libraries' service excellence philosophy and policy, bring the service excellence concept to the attention of every library employee, and recommend approaches for recognizing outstanding staff service. The members of the task force--two library…

State Univ. of New York, Buffalo. Univ. Libraries.

357

Axial forces in piping systems  

SciTech Connect

This paper reviews the various pipe Code requirements related to control of axial forces in above ground piping systems. With the exception of ASME Section III (for seismic anchor motions) the Codes do not have specific limits for stresses induced by axial forces (F/A). These new limits will require changes to existing piping analysis computer programs. The present Code explicit limits on stresses due to bending moments result in implicit limits on axial stresses and associated axial forces. It is shown that the limitations of stresses in piping components due to bending moments result in corresponding conservative limits in stresses due to axial forces. Hence limits on axial forces are not required.

Wais, E.A. [Wais and Associates, Inc., Norcross, GA (United States)

1996-12-31

358

Force distributions and force chains in random stiff fiber networks  

E-print Network

We study the elasticity of random stiff fiber networks. The elastic response of the fibers is characterized by a central force stretching stiffness as well as a bending stiffness that acts transverse to the fiber contour. Previous studies have shown that this model displays an anomalous elastic regime where the stretching mode is fully frozen out and the elastic energy is completely dominated by the bending mode. We demonstrate by simulations and scaling arguments that, in contrast to the bending dominated \\emph{elastic energy}, the equally important \\emph{elastic forces} are to a large extent stretching dominated. By characterizing these forces on microscopic, mesoscopic and macroscopic scales we find two mechanisms of how forces are transmitted in the network. While forces smaller than a threshold $F_c$ are effectively balanced by a homogeneous background medium, forces larger than $F_c$ are found to be heterogeneously distributed throughout the sample, giving rise to highly localized force-chains known from granular media.

Claus Heussinger; Erwin Frey

2007-05-10

359

International Student and  

E-print Network

Admissions Disability Services International Student and Scholar Services International Student for faculty and staff support · Research and discussion on the international student experience · Managing of Continuing Education Theresa Ganglghassemlouei and Beth Isensee, International Student and Scholar Services

Amin, S. Massoud

360

Force Sensing in Surgical Sutures  

PubMed Central

The tension in a suture is an important factor in the process of wound healing. If there is too much tension in the suture, the blood flow is restricted and necrosis can occur. If the tension is too low, the incision opens up and cannot heal properly. The purpose of this paper is to describe the design and evaluation of the Stitch Force (SF) sensor and the Hook-In Force (HIF) sensor. These sensors were developed to measure the force on a tensioned suture inside a closed incision and to measure the pulling force used to close the incision. The accuracy of both sensors is high enough to determine the relation between the force in the thread of a stitch and the pulling force applied on the suture by the physician. In a pilot study, a continuous suture of 7 stitches was applied on the fascia of the abdominal wall of multiple pigs to study this relationship. The results show that the max force in the thread of the second stitch drops from 3 (SD 1.2) to 1 (SD 0.3) newton after the 4th stitch was placed. During placement of the 5th, 6th and 7th stitch, the force in the 2nd stitch was not influenced anymore. This study indicates that in a continuous suture the force in the thread remains constant up to more than 3 stiches away from the pulled loose end of the suture. When a force feedback tool is developed specially for suturing in surgery on patients, the proposed sensors can be used to determine safety threshold for different types of tissue and sutures. PMID:24376812

Horeman, Tim; Meijer, Evert-jan; Harlaar, Joris J.; Lange, Johan F.; van den Dobbelsteen, John J.; Dankelman, Jenny

2013-01-01

361

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

362

INTERNATIONAL PEER GROUP INTERNATIONAL PEER GROUP  

E-print Network

... INTERNATIONAL STUDENTS INTERNATIONAL PEER GROUP MISSION INTERNATIONAL PEER GROUP · Organize regular academic of any mentor to discuss questions you may have · Learn about campus clubs and organizations at UCI into university life. IPG provides academic and social support to engage international students in UC Irvine

Stanford, Kyle

363

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

364

Force transmissibility versus displacement transmissibility  

NASA Astrophysics Data System (ADS)

It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this novel approach significantly decreases the computational effort when compared to conventional approaches, as it requires only local information of the sets of coordinates involved. Numerical simulations and experimental examples are presented and discussed, to illustrate the proposed developments.

Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

2014-10-01

365

Observation of microtubules with scanning force microscopy in liquid  

NASA Astrophysics Data System (ADS)

We present the application of scanning force microscopy using the jumping mode to investigate microtubules adsorbed to glass in air and in liquid. To fix the microtubules the glass surfaces were silanized with aminopropyl-triethoxy-silane. The observed structures ranged from disrupted microtubules in air to intact microtubules in liquid. Intact microtubules show heights between 20 and 24 nm confirming the diameter found in electron microscopy studies. The force applied by the tip was critical for the microtubule height, indicating deformation by the tip. Internal structure, corresponding to protofilaments, was found.

de Pablo, P. J.; Schaap, I. A. T.; Schmidt, C. F.

2003-02-01

366

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

367

Flagellar force production during regeneration in Chlamydomonas reinhardtii  

NASA Astrophysics Data System (ADS)

Several respiratory, digestive, and reproductive disorders originate with motional dysfunction of cilia and flagella. The usefulness of cilia and flagella is understood, but the internal mechanism for creating their breast stroke-like motion is not. This study reports on standardization of calibration, trapping and cell movement recording methods. Our techniques permit us to measure the flagellar swimming force of Chlamydomonas during flagella regeneration. We find that as flagella length increases, the flagellar force is maximized after 50% of full length is achieved except for a significant dip at 75% of full length. These results raise many questions regarding the flagella infrastructure.

Yukich, John N.; Clodfelter, Catherine; Bernd, Karen K.

2009-11-01

368

Calibration Designs for Non-Monolithic Wind Tunnel Force Balances  

NASA Technical Reports Server (NTRS)

This research paper investigates current experimental designs and regression models for calibrating internal wind tunnel force balances of non-monolithic design. Such calibration methods are necessary for this class of balance because it has an electrical response that is dependent upon the sign of the applied forces and moments. This dependency gives rise to discontinuities in the response surfaces that are not easily modeled using traditional response surface methodologies. An analysis of current recommended calibration models is shown to lead to correlated response model terms. Alternative modeling methods are explored which feature orthogonal or near-orthogonal terms.

Johnson, Thomas H.; Parker, Peter A.; Landman, Drew

2010-01-01

369

Gravity and Orbits: Gravitational Force  

NSDL National Science Digital Library

This Science Object is the second of three Science Objects in the Gravity and Orbits SciPack. It investigates the variables that influence gravitational forces acting on objects. Mass is a measure of the amount of matter that makes up an object (regardless of where that object is located) and weight is a measure of the gravitational force acting on an object. The strength of the gravitational force between masses is proportional to the product of the masses and inversely proportional to the square of the distance between them. Gravity will cause all objects at the same distance from Earth's surface to fall toward Earth with the same acceleration regardless of their mass. Learning Outcomes:� Identify variables that affect the strength of the gravitational force acting between any two objects.� Provide a quantitative description of the relationship between the mass of two object and the gravitational force between them.� Provide a qualitative description of the relationship between the mass of two objects and the gravitational force between them.� Provide a quantitative description of the relationship between distance and gravitational force. � Provide a qualitative description of the inverse square relationship.� Recognize the effect of air resistance on object falling near Earth's surface, and thus be able to explain why two objects with different masses, at the same distance from Earth's surface, will have equal accelerations if air resistance is ignored.

National Science Teachers Association (NSTA)

2006-11-01

370

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.

371

Force of an Actin Spring  

PubMed Central

Cellular movements are produced by forces. Typically, cytoskeletal proteins such as microtubules and actin filaments generate forces via polymerization or in conjunction with molecular motors. However, the fertilization of a Limulus polyphemus egg involves a third type of actin-based cellular engine—a biological spring. During the acrosome reaction, a 60-?m long coiled and twisted bundle of actin filaments straightens and extends from a sperm cell, penetrating the vitelline layer surrounding the egg. A subtle overtwist of 0.2°/subunit underlies the mechanochemical basis for the extension of this actin spring. Upon calcium activation, this conformational strain energy is converted to mechanical work, generating the force required to extend the bundle through the vitelline layer. In this article, we stall the extension of the acrosome bundle in agarose gels of different concentrations. From the stall forces, we estimate a maximum force of 2 nN and a puncturing pressure of 1.6 MPa. We show the maximum force of extension is three times larger than the force required to puncture the vitelline layer. Thus, the elastic strain energy stored in the acrosome bundle is more than sufficient to power the acrosome reaction through the egg envelope. PMID:17351007

Shin, Jennifer H.; Tam, Barney K.; Brau, Ricardo R.; Lang, Matthew J.; Mahadevan, L.; Matsudaira, Paul

2007-01-01

372

Report of the Fermilab ILC Citizens' Task Force  

SciTech Connect

Fermi National Accelerator Laboratory convened the ILC Citizens' Task Force to provide guidance and advice to the laboratory to ensure that community concerns and ideas are included in all public aspects of planning and design for a proposed future accelerator, the International Linear Collider. In this report, the members of the Task Force describe the process they used to gather and analyze information on all aspects of the proposed accelerator and its potential location at Fermilab in northern Illinois. They present the conclusions and recommendations they reached as a result of the learning process and their subsequent discussions and deliberations. While the Task Force was charged to provide guidance on the ILC, it became clear during the process that the high cost of the proposed accelerator made a near-term start for the project at Fermilab unlikely. Nevertheless, based on a year of extensive learning and dialogue, the Task Force developed a series of recommendations for Fermilab to consider as the laboratory develops all successor projects to the Tevatron. The Task Force recognizes that bringing a next-generation particle physics project to Fermilab will require both a large international effort and the support of the local community. While the Task Force developed its recommendations in response to the parameters of a future ILC, the principles they set forth apply directly to any large project that may be conceived at Fermilab, or at other laboratories, in the future. With this report, the Task Force fulfills its task of guiding Fermilab from the perspective of the local community on how to move forward with a large-scale project while building positive relationships with surrounding communities. The report summarizes the benefits, concerns and potential impacts of bringing a large-scale scientific project to northern Illinois.

none,

2008-06-01

373

International data base.  

PubMed

The concept of the International Data Base (IDB) grew from recognition of the need for timely, high quality information on the demographic, social and economic characteristics of foreign countries. During the past 2 decades, the Bureau of the Census, US Department of Commerce, has been compiling, analyzing and evaluating international demographic data and, to a lesser extent, socioeconomic data with particular emphasis on developing countries. In 1979, at the request of the Office of Women in Development at the Agency for International Development, a computerized data base of demographic and socioeconomic statistics that could be used to assess the status of women in developing countries was established. The major categories of data now being included in IDB are as follows: population by age and sex; vital rates, infant mortality and life tables; health and nutrition; fertility and child survivorship; migration; provinces and cities; family planning; ethnic, religious and language groups; literacy and education; labor force, employment, income and gross national product; and household size and housing indicators. The Bureau, through its Center for International Reserch (CIR), developed a computerized central depository of demographic, social and economic data for all countries of the world to serve the needs of the public and private sectors. The initial emphasis was on demographic and social data, since these subject areas are those for which a vast amount of data has already been compiled, analyzed and evaluated by CIR staff. However, meetings are being planned with users to determine the additional types of data that are desired, particularly in the economic and health-related areas. IDB includes data for all countries of the world, by urban and rural residence. The time coverage is from 1950 to the present. Data sources include: population and industrial censuses and surveys, administrative records, population registers, statistical publications, research papers, and personal communication with foreign officials and researchers. Quality and quantity of data varies from country to country, depending on the quality of field work, the sample design, the accuracy of information given by respondents, the adequacy of tabulations or publications, and specification or knowledge of data needs. Data for each country are presented according to the definitions prescribed by that country; no attempt has been made by the Bureau to standardize definitions of concepts. Model 204, a data base management system developed by the Computer Corporation of America, was adopted for the IDB project. Technical details of this system are provided in the annex, as well as lists of tables included in the IDB. PMID:12267286

Quick, S

1984-12-01

374

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

375

Globalization and the Growth of International Educational Testing and National Assessment  

ERIC Educational Resources Information Center

In this article, the authors develop an argument about the global forces that have led to the explosive growth of national educational assessment and international testing. In particular, the authors argue that the international acceptance of testing comes from key ideological forces in the world polity that are associated with the accelerating…

Kamens, David H.; McNeely, Connie L.

2010-01-01

376

Casimir force between liquid metals  

NASA Astrophysics Data System (ADS)

We present a theoretical calculation of the Casimir force between liquid metals at room temperature using as case studies mercury (Hg) and eutectic indium gallium (EInGa). The surface tension of the liquids creates surfaces of zero roughness that are truly equipotential, an ideal characteristic for Casimir force experiments. As we show the dielectric properties of Au, EInGa and Hg are very similar and the difference on the Casimir force between Au and EInGa and Au and Hg is less than 4%. Based on these results, a modification of the IUPUI experiment for detecting deviations of Newtonian gravity is proposed.

Esquivel-Sirvent, R.; Escobar, J. V.

2014-08-01

377

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.

2013-01-01

378

Optical forces in plasmonic nanoantennas  

SciTech Connect

The optical forces acting on nanoparticles in V-shaped plasmonic resonators with a high local-field gain have been investigated. Two versions are considered, which make it possible to implement either attractive or repulsive gradient optical forces. A plasmonic resonator is proposed, which can focus 350-nm radiation and implement a repulsive gradient force. It has been shown for the first time that a perturbation induced by a nanoparticle redistributes the field in the resonator so that additional intensity peaks arise in both versions to hold the nanoparticle in the resonator by forming an optical trap. (nanooptics)

Shalin, A S; Sukhov, S V

2012-04-30

379

Roller Coaster G-Forces  

NSDL National Science Digital Library

This page, created by Tom Henderson of Glenbrook South High School, features an animated image and a discussion of the forces involved in going through a looping coaster. This page is fairly simplistic, but it does provides links to other helpful physics resources. Some of these include lesson plans discussing the subjects of: acceleration, net force and acceleration, free body diagrams, weightlessness, circular motion and tangential velocity, circular motion and acceleration, the centripetal force requirement and amusement park physics. All together, this is a nice resource for an upper high school to lower undergraduate level course in basic physics.

Henderson, Tom

2009-04-08

380

Boiling-Water Reactor internals aging degradation study. Phase 1  

Microsoft Academic Search

This report documents the results of an aging assessment study for boiling water reactor (BWR) internals. Major stressors for BWR internals are related to unsteady hydrodynamic forces generated by the primary coolant flow in the reactor vessel. Welding and cold-working, dissolved oxygen and impurities in the coolant, applied loads and exposures to fast neutron fluxes are other important stressors. Based

Luk

1993-01-01

381

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010  

E-print Network

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010 of the International Congress of Mathematicians was supported by NSF grant DMS- 0757507. I would like to thank Ilijas suggestions. Abstract. The Proper Forcing Axiom is a powerful extension of the Baire Category Theorem which

Moore, Justin Tatch

382

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010  

E-print Network

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010 The Proper's preparation of this article and his travel to the 2010 meeting of the International Congress of Mathematicians for reading preliminary drafts of this article and o#ering suggestions. Abstract. The Proper Forcing Axiom

Moore, Justin Tatch

383

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010  

E-print Network

Proceedings of the International Congress of Mathematicians Hyderabad, India, 2010 The Proper's preparation of this article and his travel to the 2010 meeting of the International Congress of Mathematicians for reading preliminary drafts of this article and offering suggestions. Abstract. The Proper Forcing Axiom

Moore, Justin Tatch

384

Improving the Delivery of the Undergraduate International Business Course.  

ERIC Educational Resources Information Center

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

Thanopoulos, John; And Others

1995-01-01

385

International Collaboration under Threat: A Field Study in Kabul  

Microsoft Academic Search

This report examines Dutch military personnel's attitudes toward international cooperation, while these attitudes were expressed under threatening (during the International Security Assistance Force (ISAF) mission in Afghanistan) or nonthreatening circumstances (in Europe). Findings indicate that concerns about death were significantly more present in Afghanistan relative to Europe, and in Afghanistan, concerns about death were found to be negatively correlated with

Mark Dechesne; Coen Van Den Berg; Joseph Soeters

2007-01-01

386

A topaz international program overview  

SciTech Connect

Little did these visionaries know that the formation of the ``TOPAZ II Program,`` using former military space power technology of the Soviet Union, would become the preeminent example of technology cooperation between two former adversaries. A unique teaming arrangement formed in New Mexico, called the New Mexico Strategic Alliance and consisting of the Air Force Phillips Laboratory, Sandia National Laboratories, the University of New Mexico, and Los Alamos Nationalo Laboratory, was a key ingredient in making this program a success. A brief summary of some of the highlights of this technology partnership is given to explain how international patnerships of this type can enable commercialization and technology transfer.

Thome, F.V.; Wyant, F.J. [USAF Phillips Laboratory/VTPN, 901 University Blvd SE, Albuquerque, New Mexico 87106 (United States); Mulder, D. [Sandia National Laboratories, 901 University Blvd SE, Albuquerque, New Mexico 87106 (United States); McCarson, T.D. Jr. [New Mexico Engineering Research Institute, University of New Mexico, 901 University Blvd, SE Albuquerque, New Mexico 87106 (United States); Ponomarev-Stepnoi, N.N. [RRC Kurchatov Institute, Kurchatov SQ 1, Moscow, Russia 123182 (Russian Federation)

1995-01-20

387

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

388

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

389

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

390

Direct detection of intermolecular forces by atomic force microscopy  

NASA Astrophysics Data System (ADS)

The phenomenon of adhesion appears in various applications of everyday life, ranging from PostIt Notes(TM) and Scotch Tape(TM), to the assembly of aircraft and space shuttles. However, adhesion on the molecular scale is fundamentally different from the adhesion that we experience in the macroscopic world. While macroscopic objects require special adhesives or glues to bind them together, microscale and nanoscale objects and molecules commonly have a high affinity to adhere to each other. A detailed description of intermolecular forces is therefore of key importance in order to understand a wide range of phenomena, ranging from macroscopic properties of materials to molecular recognition. Two key aspects of the atomic force microscope (AFM), namely its sensitivity to sub-nanoNewton forces and its very sharp probe, offer the opportunity to measure interactions between very small numbers of molecules. Through chemical tailoring of both substrates and AFM probes with self-assembled monolayers (SAMs), measurements of forces acting between specific functional groups can be measured. Furthermore, the force required to rupture a single chemical bond can be obtained by a detailed analysis of the histograms of rupture forces. A new model was derived to examine the relationship between the various experimental variables and the shape of histograms of rupture forces when discrete chemical bonds are formed between the AFM probe and substrate. Calculations based on the model demonstrated that in measurements aimed at detecting single bond rupture forces, strict limits are put on the size of the AFM probe, the relative magnitude of the interfacial energies and the bond formation probability. These results were used in two experimental systems where the single bond rupture force was successfully measured: (i) the abstraction of a single Au-S complex from an Au coated AFM probe; and (ii) the rupture of a single charge-transfer (CT) complex between tetramethylphenylenediamine (TMPD) and tetracyanoquinodimethane (TCNQ). Measurements involving only one molecule at a time were conducted using polymer chains chemically grafted to the AFM probe and substrate. In these measurements, the effect of the solvent on the elasticity of the poly-ethylene-propylene oligomers was directly observed in the force-elongation profile.

Skulason, Hjalti

391

Investigating Forces: Balloon car activity  

NSDL National Science Digital Library

This is a guided inquiry-based lab that investigates forces exerted on a group of student-designed and engineered "balloon cars". Each group of students is then challenged to build a "balloon car" that travels a maximum distance.

392

Physlet Force Concept Inventory: Gravity  

NSDL National Science Digital Library

A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy's hand but before it touches the ground, and assume that the forces exerted by the air are negligible.

Christian, Wolfgang; Belloni, Mario

2006-01-13

393

Forced motion near black holes  

SciTech Connect

We present two methods for integrating forced geodesic equations in the Kerr spacetime. The methods can accommodate arbitrary forces. As a test case, we compute inspirals caused by a simple drag force, mimicking motion in the presence of gas. We verify that both methods give the same results for this simple force. We find that drag generally causes eccentricity to increase throughout the inspiral. This is a relativistic effect qualitatively opposite to what is seen in gravitational-radiation-driven inspirals, and similar to what others have observed in hydrodynamic simulations of gaseous binaries. We provide an analytic explanation by deriving the leading order relativistic correction to the Newtonian dynamics. If observed, an increasing eccentricity would thus provide clear evidence that the inspiral was occurring in a nonvacuum environment. Our two methods are especially useful for evolving orbits in the adiabatic regime. Both use the method of osculating orbits, in which each point on the orbit is characterized by the parameters of the geodesic with the same instantaneous position and velocity. Both methods describe the orbit in terms of the geodesic energy, axial angular momentum, Carter constant, azimuthal phase, and two angular variables that increase monotonically and are relativistic generalizations of the eccentric anomaly. The two methods differ in their treatment of the orbital phases and the representation of the force. In the first method, the geodesic phase and phase constant are evolved together as a single orbital phase parameter, and the force is expressed in terms of its components on the Kinnersley orthonormal tetrad. In the second method, the phase constants of the geodesic motion are evolved separately and the force is expressed in terms of its Boyer-Lindquist components. This second approach is a direct generalization of earlier work by Pound and Poisson [A. Pound and E. Poisson, Phys. Rev. D 77, 044013 (2008).] for planar forces in a Schwarzschild background.

Gair, Jonathan R. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Flanagan, Eanna E. [Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853 (United States); Drasco, Steve [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, D-14476 Golm (Germany); Theoretical Astrophysics, California Institute of Technology, Pasadena, California 91125 (United States); California Polytechnic State University, San Luis Obispo, California 93405 (United States); Hinderer, Tanja [Theoretical Astrophysics, California Institute of Technology, Pasadena, California 91125 (United States); Babak, Stanislav [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, D-14476 Golm (Germany)

2011-02-15

394

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

395

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. PMID:21423821

Bohra, Pratikshya; Massey, Douglas S.

2011-01-01

396

Contact forces in a granular packing  

Microsoft Academic Search

We present the results of a systematic numerical investigation of force distributions in granular packings. We find that all the main features of force transmission previously established for two-dimensional systems of hard particles hold in three-dimensional systems and for soft particles, too. In particular, the probability distribution of normal forces falls off exponentially for forces above the mean force. For

Farhang Radjai; Stéphane Roux; Jean Jacques Moreau

1999-01-01

397

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

398

Air Force Research Laboratory AFRLAir Force Research Laboratory AFRL Science and Technology for Tomorrow's Air and Space Force  

E-print Network

JAV Air Force Research Laboratory AFRLAir Force Research Laboratory AFRL Science and Technology activities in the Air Force Research Laboratory, contact TECH CONNECT, AFRL/XPTC, (800) 203-6451 and you

Deloach, Scott A.

399

Population commission discusses international migration.  

PubMed

At the 30th session of the Commission on Population and Development during February 24-28, 1997, international migration was the main topic, with special linkages between migration and development and on gender issues and the family. New and emerging issues were also considered. Members stressed the need for more reliable data on migration, the direction of migrants flows, and the characteristics of migrants. The Commission requested a task force on basic social services to hold a technical symposium of experts on international migration in 1998. Its chair, Dr. Nafis Sadik, said that migration issues should based on the reality of choice not on coercive measures or quotas. Almost half of the migrants globally are women. The Commission was given a new impetus by the International Conference on Population and Development held at Cairo in 1994. Migration pressures intensified in the second half of the 1980s and in the early 1990s, creating areas of concern: the negative impact of short-term migration on working conditions in host countries; migration pressures emanating from climatic change; the protection of migrant women and their children; the right of receiving countries to regulate access to their territory; the adverse consequences of forced migration; the situation of persons whose asylum claims have been rejected; the trafficking in women and children, prostitution and coercive adoption; and the sudden and massive arrival of refugees in need of international protection. The 1998 session of the Commission will feature the theme of health and mortality, with special emphasis on the linkages between health and development and on gender and age. PMID:12292475

1997-01-01

400

Swelling and surface forces-induced instabilities in nanoscopic polymeric structures  

NASA Astrophysics Data System (ADS)

For closely spaced, nanolithographically defined lines, a thin wall of resist remains to act as the metal line spacer. When exposed to a developer, and then rinsing solution, closely spaced resist walls may become unstable as a result of two effects: (1) internal stresses due to swelling, and (2) lateral surface forces between adjacent walls. In this article we perform a linear stability analysis of a thin polymer wall under the simultaneous action of internal stresses and lateral surface forces. We calculate a stability boundary, and show that internal stresses are necessary for the formation of deformation patterns of finite wavelength. We find that, for slightly subcritical swelling stresses a small lateral force can induce buckling, while, for slightly subcritical surface tractions large internal stresses are necessary to induce instability. The theoretical predictions are in good agreement with experimental data on poly(methyl-methacrylate) walls produced by electron beam lithography.

Hill, Davide A.; Huang, Xiaokang; Bazán, Greg; Bernstein, Gary H.

1992-11-01

401

Forces on a spherical conducting particle in E × B fields  

NASA Astrophysics Data System (ADS)

The forces acting on a spherical conducting particle in a transversely flowing magnetized plasma are calculated in the entire range of magnetization and Debye length, using the particle code SCEPTIC3D (Patacchini and Hutchinson 2010 Plasma Phys. Control. Fusion 52 035005, 2011 Plasma Phys. Control. Fusion 53 025005). In short Debye length (i.e. high density) plasmas, both the ion-drag and Lorentz force arising from currents circulating inside the dust show strong components antiparallel to the convective electric field, suggesting that a free dust particle should gyrate faster than what predicted by its Larmor frequency. In intermediate to large Debye length conditions, by a downstream depletion effect already reported in unmagnetized strongly collisional regimes, the ion-drag in the direction of transverse flow can become negative. The internal Lorentz force, however, remains in the flow direction, and large enough in magnitude so that no spontaneous dust motion should occur.

Patacchini, Leonardo; Hutchinson, Ian H.

2011-06-01

402

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

403

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

404

Einstein's osmotic equilibrium of colloidal suspensions in conservative force fields  

NASA Astrophysics Data System (ADS)

Predicted by Einstein in his 1905 paper on Brownian motion, colloidal particles in suspension reach osmotic equilibrium under gravity. The idea was demonstrated by J.B. Perrin to win Nobel Prize in Physics in 1926. We show Einstein's equation for osmotic equilibrium can be applied to colloids in a conservative force field generated by optical gradient forces. We measure the osmotic equation of state of 100nm Polystyrene latex particles in the presence of KCl salt and PEG polymer. We also obtain the osmotic compressibility, which is important for determining colloidal stability and the internal chemical potential, which is useful for predicting the phase transition of colloidal systems. This generalization allows for the use of any conservative force fields for systems ranging from colloidal systems to macromolecular solutions.

Fu, Jinxin; Ou-Yang, H. Daniel

2014-09-01

405

The international lithosphere program  

Microsoft Academic Search

The International Lithosphere Program is a new international interdisciplinary research program in the solid earth sciences that has been established by the International Council of Scientific Unions (ICSU) at the joint request of the International Union of Geodesy and Geophysics (IUGG) and the International Union of Geological Sciences (IUGS). Its goal is a better understanding of the development of the

Edward A. Flinn

1982-01-01

406

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.

407

To be submitted to the International Geoscience and Remote Sensing Symposium (IGARSS), Honolulu, Hawaii, 24-28 July 2000 This work was sponsored by the Department of the Air Force under Contract F19628-95-C-0002. Opinions, interpretations, conclusions,  

E-print Network

DESCRIPTION The hyperspectral data used in this study were collected by the airborne HYDICE sensor [2]. HYDICE are those of the author and are not necessarily endorsed by the United States Air Force. Hyperspectral Data-optical sensors, with their hundreds of contiguous spectral bands, are a rich data source useful in a variety

Kerekes, John

408

Force on an Asymmetric Capacitor  

E-print Network

When a high voltage (~30 kV) is applied to a capacitor whose electrodes have different physical dimensions, the capacitor experiences a net force toward the smaller electrode (Biefeld-Brown effect). We have verified this effect by building four capacitors of different shapes. The effect may have applications to vehicle propulsion and dielectric pumps. We review the history of this effect briefly through the history of patents by Thomas Townsend Brown. At present, the physical basis for the Biefeld-Brown effect is not understood. The order of magnitude of the net force on the asymmetric capacitor is estimated assuming two different mechanisms of charge conduction between its electrodes: ballistic ionic wind and ionic drift. The calculations indicate that ionic wind is at least three orders of magnitude too small to explain the magnitude of the observed force on the capacitor. The ionic drift transport assumption leads to the correct order of magnitude for the force, however, it is difficult to see how ionic drift enters into the theory. Finally, we present a detailed thermodynamic treatment of the net force on an asymmetric capacitor. In the future, to understand this effect, a detailed theoretical model must be constructed that takes into account plasma effects: ionization of gas (or air) in the high electric field region, charge transport, and resulting dynamic forces on the electrodes. The next series of experiments should determine whether the effect occurs in vacuum, and a careful study should be carried out to determine the dependence of the observed force on gas pressure, gas species and applied voltage.

Thomas B. Bahder; Chris Fazi

2002-10-31

409

Note: Helical nanobelt force sensors  

SciTech Connect

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

Hwang, G. [Laboratory for Photonics and Nanostructures, Centre National de la Recherche Scientifique, Marcoussis 91460 (France); Hashimoto, H. [Department of EECE, Chuo University 1-13-27 Kasuga, Bunkyo-ku, Tokyo (Japan)

2012-12-15

410

Forces driving epithelial wound healing  

NASA Astrophysics Data System (ADS)

A fundamental feature of multicellular organisms is their ability to self-repair wounds through the movement of epithelial cells into the damaged area. This collective cellular movement is commonly attributed to a combination of cell crawling and `purse-string’ contraction of a supracellular actomyosin ring. Here we show by direct experimental measurement that these two mechanisms are insufficient to explain force patterns observed during wound closure. At early stages of the process, leading actin protrusions generate traction forces that point away from the wound, showing that wound closure is initially driven by cell crawling. At later stages, we observed unanticipated patterns of traction forces pointing towards the wound. Such patterns have strong force components that are both radial and tangential to the wound. We show that these force components arise from tensions transmitted by a heterogeneous actomyosin ring to the underlying substrate through focal adhesions. The structural and mechanical organization reported here provides cells with a mechanism to close the wound by cooperatively compressing the underlying substrate.

Brugués, Agustí; Anon, Ester; Conte, Vito; Veldhuis, Jim H.; Gupta, Mukund; Colombelli, Julien; Muñoz, José J.; Brodland, G. Wayne; Ladoux, Benoit; Trepat, Xavier

2014-09-01

411

Constructing the Self-Force  

NASA Astrophysics Data System (ADS)

I present an overview of the methods involved in the computation of the scalar, electromagnetic, and gravitational self-forces acting on a point particle moving in a curved spacetime. For simplicity, the focus here will be on the scalar self-force. The lecture follows closely my review article on this subject [E. Poisson, Living Rev. Relativ. 7 (2004), http://www.livingreviews.org/lrr-2004-6]. I begin with a review of geometrical elements (Synge's world function, the parallel propagator). Next I introduce useful coordinate systems (Fermi normal coordinates and retarded light-cone coordinates) in a neighborhood of the particle's world line. I then present the wave equation for a scalar field in curved spacetime and the equations of motion for a particle endowed with a scalar charge. The wave equation is solved by means of a Green's function, and the self-force is constructed from the field gradient. Because the retarded field is singular on the world line, the self-force must involve a regularized version of the field gradient, and I describe how the regular piece of the self-field can be identified. In the penultimate section of the lecture I put the construction of the self-force on a sophisticated axiomatic basis, and in the concluding section I explain how one can do better by abandoning the dangerous fiction of a point particle.

Poisson, Eric

412

Anomalous Dynamics of Forced Translocation  

E-print Network

We consider the passage of long polymers of length N through a hole in a membrane. If the process is slow, it is in principle possible to focus on the dynamics of the number of monomers s on one side of the membrane, assuming that the two segments are in equilibrium. The dynamics of s(t) in such a limit would be diffusive, with a mean translocation time scaling as N^2 in the absence of a force, and proportional to N when a force is applied. We demonstrate that the assumption of equilibrium must break down for sufficiently long polymers (more easily when forced), and provide lower bounds for the translocation time by comparison to unimpeded motion of the polymer. These lower bounds exceed the time scales calculated on the basis of equilibrium, and point to anomalous (sub-diffusive) character of translocation dynamics. This is explicitly verified by numerical simulations of the unforced translocation of a self-avoiding polymer. Forced translocation times are shown to strongly depend on the method by which the force is applied. In particular, pulling the polymer by the end leads to much longer times than when a chemical potential difference is applied across the membrane. The bounds in these cases grow as N^2 and N^{1+\

Yacov Kantor; Mehran Kardar

2003-10-22

413

Sensing mode atomic force microscope  

DOEpatents

An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

Hough, Paul V. C. (Port Jefferson, NY); Wang, Chengpu (Upton, NY)

2003-01-01

414

Sideways Force Produced During Disruptions  

NASA Astrophysics Data System (ADS)

We extend previous studies [1] of vertical displacement events (VDE) which can produce disruptions. The emphasis is on the non axisymmetric ``sideways'' wall force Fx. Simulations are performed using the M3D [2] code. A VDE expels magnetic flux through the resistive wall until the last closed flux surface has q < 3. At this point the plasma is unstable to an (m,n) = (2,1) mode. A theory of sideways force produced by this mode in the presence of a VDE is presented. The wall force depends strongly on ??w, where ? is the mode growth rate and ?w is the wall resistive penetration time. The force Fx is largest when ??w is a constant of order unity, which depends on the initial conditions. For large values of ??w, the wall force asymptotes to a relatively smaller value, well below the critical value ITER is designed to withstand. The principle of disruption mitigation by massive gas injection is to cause a disruption with large ??w. [4pt] [1] H. R. Strauss, R. Paccagnella, and J. Breslau,Phys. Plasmas 17, 082505 (2010) [2] W. Park, E.V. Belova, G.Y. Fu, X. Tang, H.R. Strauss, L.E. Sugiyama, Phys. Plasmas 6, 1796 (1999).

Strauss, H. R.; Paccagnella, R.; Breslau, J.; Jardin, S.; Sugiyama, L.

2012-10-01

415

Wall force produced during disruptions  

NASA Astrophysics Data System (ADS)

The study of disruptions is of great importance for ITER. Previous work on disruptions [1] is extended to compute toroidally asymmetric wall force in ITER, using the M3D code. The disruptions are produced by n = 1 resistive wall modes or external kink modes. A thin wall resistive boundary model is used to calculate the wall forces. The symmetric wall force, produced by a VDE, and the asymmetric wall force, produced by n = 1 modes, are comparable in magnitude. It is found that the asymmetric and axisymmetric forces scale with the growth rate of the instability multiplied by the square of the current divided by magnetic field. A similar scaling was reported for VDEs in JET [2]. Numerically, the study of disruptions is very challenging. In the M3D extended MHD code, dealiasing was applied in the toroidal direction. Advection terms were treated with a numerical upwind method. These techniques provided sufficient numerical stability to simulate entire disruption events. [4pt] [1] R. Paccagnella, H. R. Strauss, and J. Breslau, Nucl. Fusion (2009) 49 035003. [2] V. Riccardo, T. C. Hender, P. J. Lomas, et al., Plasma Phys. Control. Fusion (2004)

Strauss, H.; Paccagnella, R.; Breslau, J.

2009-11-01

416

Wall Force in Tokamak Disruptions  

NASA Astrophysics Data System (ADS)

Disruptions in tokamaks produce forces on conducting structures surrounding a tokamak. These forces are a serious concern for the operation of ITER, especially the toroidally asymmetric forces. We continue numerical resistive MHD studies of disruptions reported previously [1]. The model includes a resistive wall in order to allow the magnetic field to penetrate. We carry out numerical simulations with the M3D [2] code, in which the disruption consists of a vertical displacement event (VDE) combined with an external kink, resistive wall mode, or a pressure driven instability. The radial force exerted by the magnetic field on the wall is proportional to the magnetic pressure difference across the wall. Studies are being carried out to determine how the toroidally asymmetric wall force is related to other features of the disruption, such as the toroidal peaking factor (TPF) and halo current fraction. [1] R. Paccagnella, H. Strauss, J. Breslau, submitted to Nucl. Fusion (2008); B.A.P.S. 53, CP6.00067 (2008) [2] W. Park, E. V. Belova, G. Y. Fu, X. Z. Tang, H. R. Strauss, L. E. Sugiyama, Phys. Plasmas 6, 1796 (1999)

Strauss, Henry; Paccagnella, Roberto; Breslau, Joshua

2009-05-01

417

Forces in electromagnetic field and gravitational field  

E-print Network

The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in the interplanetary space between the sun and the earth.

Zihua Weng

2008-06-21

418

Proceedings of the International Symposium on Music Acoustics (Associated Meeting of the International Congress on Acoustics)  

E-print Network

of the International Congress on Acoustics) 25-31 August 2010, Sydney and Katoomba, Australia ISMA 2010, associated, and two further parameters control the lip force and its position of application. The precision and short-term and limitations may be avoided by using artificial mouths (e.g. [8]). These and more elaborate playing machines

New South Wales, University of

419

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

420

Note on forced Burgers turbulence  

SciTech Connect

A putative powerlaw range of the probability density of velocity gradient in high-Reynolds-number forced Burgers turbulence is studied. In the absence of information about shock locations, elementary conservation and stationarity relations imply that the exponent {minus}{alpha} in this range satisfies {alpha}{ge}3, if dissipation within the power-law range is due to isolated shocks. A generalized model of shock birth and growth implies {alpha}=7/2 if initial data and forcing are spatially homogeneous and obey Gaussian statistics. Arbitrary values {alpha}{ge}3 can be realized by suitably constructed homogeneous, non-Gaussian initial data and forcing. {copyright} {ital 1999 American Institute of Physics.}

Kraichnan, R.H. [PMB 108, 369 Montezuma, Santa Fe, New Mexico 87501-2626 (United States)] [PMB 108, 369 Montezuma, Santa Fe, New Mexico 87501-2626 (United States)

1999-12-01

421

Nuclear force in Lattice QCD  

E-print Network

We perform the quenched lattice QCD analysis on the nuclear force (baryon-baryon interactions). We employ $20^3\\times 24$ lattice at $\\beta=5.7$ ($a\\simeq 0.19$ fm) with the standard gauge action and the Wilson quark action with the hopping parameters $\\kappa=0.1600, 0.1625, 0.1650$, and generate about 200 gauge configurations. We measure the temporal correlators of the two-baryon system which consists of heavy-light-light quarks. We extract the inter-baryon force as a function of the relative distance $r$. We also evaluate the contribution to the nuclear force from each ``Feynman diagram'' such as the quark-exchange diagram individually, and single out the roles of Pauli-blocking effects or quark exchanges in the inter-baryon interactions.

T. T. Takahashi; T. Doi; H. Suganuma

2006-01-05

422

Air Force Historical Research Agency  

NSDL National Science Digital Library

Started in World War II in Washington, D.C., the Air Force Historical Research Agency (AFHRA) has the largest collection of US military aviation documents, with more than 70,000,000 pages all told within their holdings. Since 1949, it has been housed at Maxwell Air Force Base in Alabama, and is open to the general public, military students, researchers, and scholars. Visitors will find some interesting reading under the Studies tab, which includes "Numbered USAF Historical Studies", some of which are designated Secret, and others Unclassified. Also interesting are the "Short Studies on Recent Operations" available in PDF, and including such topics as "Weather in Air Campaigns, 1990-2003" and "The U.S. Air Force Response to Hurricane Katrina". Nearby, under "Other Studies", visitors will find "A Study of Females on Minuteman/Peacekeeper Crews, 31 January 1985" and "Chronology: 100 Years of Flight".

423

Ensemble Dynamics with Quantum Forces  

NASA Astrophysics Data System (ADS)

We present a new methodology for approximating the solutions of the time-dependent Schrödinger equation. Our approach is rooted in the de Broglie Bohm interpretation of the quantum theory in which the evolution of a quantum system is characterized by an ensemble of particle trajectories. The paths of these ``Bohmian'' particles are analogous to hydrodynamic trajectories and are determined by the presence of both classical and quantum forces in the system. The quantum force is due to the nonlocal interactions between particles and is related to the curvature of the quantum density. In the present study we invoke an expectation-maximization algorithm to approximate a functional form for the density of a finite ensemble of Bohmian particles. From this density information we then calculate a quantum force and propagate the system forward in time using a Verlet type integration. In what follows we will describe the details of this approach and present some numerical results.

Maddox, Jeremy; Bittner, Eric

2003-03-01

424

International Continuing Education  

E-print Network

with international clients and colleagues. Ideal for international college bound students, scholars and visiting in traumatic stress reactions as well as develop therapeutic strategies for treating traumatized clients

Saldin, Dilano

425

High-speed atomic force microscopy: imaging and force spectroscopy.  

PubMed

Atomic force microscopy (AFM) is the type of scanning probe microscopy that is probably best adapted for imaging biological samples in physiological conditions with submolecular lateral and vertical resolution. In addition, AFM is a method of choice to study the mechanical unfolding of proteins or for cellular force spectroscopy. In spite of 28 years of successful use in biological sciences, AFM is far from enjoying the same popularity as electron and fluorescence microscopy. The advent of high-speed atomic force microscopy (HS-AFM), about 10 years ago, has provided unprecedented insights into the dynamics of membrane proteins and molecular machines from the single-molecule to the cellular level. HS-AFM imaging at nanometer-resolution and sub-second frame rate may open novel research fields depicting dynamic events at the single bio-molecule level. As such, HS-AFM is complementary to other structural and cellular biology techniques, and hopefully will gain acceptance from researchers from various fields. In this review we describe some of the most recent reports of dynamic bio-molecular imaging by HS-AFM, as well as the advent of high-speed force spectroscopy (HS-FS) for single protein unfolding. PMID:24937145

Eghiaian, Frédéric; Rico, Felix; Colom, Adai; Casuso, Ignacio; Scheuring, Simon

2014-10-01

426

Force chains, microelasticity, and macroelasticity.  

PubMed

It has been claimed that quasistatic granular materials, as well as nanoscale materials, exhibit departures from elasticity even at small loadings. It is demonstrated, using 2D and 3D models with interparticle harmonic interactions, that such departures are expected at small scales [below O(100) particle diameters], at which continuum elasticity is invalid, and vanish at large scales. The models exhibit force chains on small scales, and force and stress distributions which agree with experimental findings. Effects of anisotropy, disorder, and boundary conditions are discussed as well. PMID:12190469

Goldenberg, C; Goldhirsch, I

2002-08-19

427

Force Chains, Microelasticity, and Macroelasticity  

NASA Astrophysics Data System (ADS)

It has been claimed that quasistatic granular materials, as well as nanoscale materials, exhibit departures from elasticity even at small loadings. It is demonstrated, using 2D and 3D models with interparticle harmonic interactions, that such departures are expected at small scales [below O(100) particle diameters], at which continuum elasticity is invalid, and vanish at large scales. The models exhibit force chains on small scales, and force and stress distributions which agree with experimental findings. Effects of anisotropy, disorder, and boundary conditions are discussed as well.

Goldenberg, C.; Goldhirsch, I.

2002-08-01

428

Automatic HTS force measurement instrument  

DOEpatents

A device is disclosed for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed. 3 figs.

Sanders, S.T.; Niemann, R.C.

1999-03-30

429

Illinois PER Interactive Examples: Forces  

NSDL National Science Digital Library

This is an interactive homework problem for introductory physics students relating to vector addition. Given a free-body diagram depicting three forces acting on an object, students are required to find the magnitude of the net force. A user-activated "help" sequence is provided for each step of the problem-solving, from conceptual analysis through quantitative calculation. To promote critical thinking, immediate feedback is received for both correct and incorrect responses. This item is part of a larger collection of interactive homework problems for introductory physics.

Gladding, Gary

2008-09-12

430

Automatic HTS force measurement instrument  

DOEpatents

A device for measuring the levitation force of a high temperature superconductor sample with respect to a reference magnet includes a receptacle for holding several high temperature superconductor samples each cooled to superconducting temperature. A rotatable carousel successively locates a selected one of the high temperature superconductor samples in registry with the reference magnet. Mechanism varies the distance between one of the high temperature superconductor samples and the reference magnet, and a sensor measures levitation force of the sample as a function of the distance between the reference magnet and the sample. A method is also disclosed.

Sanders, Scott T. (Valparaiso, IN); Niemann, Ralph C. (Downers Grove, IL)

1999-01-01

431

Model Engine Performance Measurement From Force Balance Instrumentation  

NASA Technical Reports Server (NTRS)

A large scale model representative of a low-noise, high bypass ratio turbofan engine was tested for acoustics and performance in the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel. This test was part of NASA's continuing Advanced Subsonic Technology Noise Reduction Program. The low tip speed fan, nacelle, and an un-powered core passage (with core inlet guide vanes) were simulated. The fan blades and hub are mounted on a rotating thrust and torque balance. The nacelle, bypass duct stators, and core passage are attached to a six component force balance. The two balance forces, when corrected for internal pressure tares, measure the total thrust-minus-drag of the engine simulator. Corrected for scaling and other effects, it is basically the same force that the engine supports would feel, operating at similar conditions. A control volume is shown and discussed, identifying the various force components of the engine simulator thrust and definitions of net thrust. Several wind tunnel runs with nearly the same hardware installed are compared, to identify the repeatability of the measured thrust-minus-drag. Other wind tunnel runs, with hardware changes that affected fan performance, are compared to the baseline configuration, and the thrust and torque effects are shown. Finally, a thrust comparison between the force balance and nozzle gross thrust methods is shown, and both yield very similar results.

Jeracki, Robert J.

1998-01-01

432

Gauge Unification of Fundamental Forces.  

National Technical Information Service (NTIS)

After having reviewed briefly the last twenty years' progress in th theory of unification, with the twin aspects of development of a gauge theory of basic interactions linked with internal symmetry and the spontaneous breaking of these symmetries, the Nob...

A. Salam

1980-01-01

433

Match your sales force structure to your business life cycle.  

PubMed

Although companies devote considerable time and money to managing their sales forces, few focus much thought on how the structure of the sales force needs to change over the life cycle of a product or a business. However, the organization and goals of a sales operation have to evolve as businesses start up, grow, mature, and decline if a company wants to keep winning the race for customers. Specifically, firms must consider and alter four factors over time: the differing roles that internal salespeople and external selling partners should play, the size of the sales force, its degree of specialization, and how salespeople apportion their efforts among different customers, products, and activities. These variables are critical because they determine how quickly sales forces respond to market opportunities, they influence sales reps' performance, and they affect companies' revenues, costs, and profitability. In this article, the authors use timeseries data and cases to explain how, at each stage, firms can best tackle the relevant issues and get the most out of their sales forces. During start-up, smart companies focus on how big their sales staff should be and on whether they can depend upon selling partners. In the growth phase, they concentrate on getting the sales force's degree of specialization and size right. When businesses hit maturity, companies should better allocate existing resources and hire more general-purpose salespeople. Finally, as organizations go into decline, wise sales leaders reduce sales force size and use partners to keep the business afloat for as long as possible. PMID:16846191

Zoltners, Andris A; Sinha, Prabhakant; Lorimer, Sally E

2006-01-01

434

Force on an Asymmetric Capacitor  

Microsoft Academic Search

When a high voltage (~30 kV) is applied to a capacitor whose electrodes have different physical dimensions, the capacitor experiences a net force toward the smaller electrode (Biefeld-Brown effect). We have verified this effect by building four capacitors of different shapes. The effect may have applications to vehicle propulsion and dielectric pumps. We review the history of this effect briefly

Thomas B. Bahder; Chris Fazi

2002-01-01

435

Air Force Programs at APL  

Microsoft Academic Search

he Applied Physics Laboratory is engaged in several diverse projects for the U.S. Air Force. These programs, which are distributed among various Laboratory depart- ments, include Flare Genesis, an Antarctic balloon mission to study the solar magnetic field, and Defense Suppression, a program to test, evaluate, and recommend improvements to the High-Speed Antiradiation Missile. Given the Laboratory's long- standing and

Peter F. Bythrow

1996-01-01

436

Atomic Force Microscopy Video Module  

NSDL National Science Digital Library

This resource, produced by the Center for Heirarchical Manufacturing at the University of Massachusetts Amherst, is part of the "Nanotechnology Education Curriculum Development Program." It is free to the public and offers information on atomic force microscopy, signal processing, nanotechnology and general instrumentation.

Calm, Yitzi; Ke, Huaje

2011-02-15

437

HyperPhysics: Coriolis Force  

NSDL National Science Digital Library

This web page contains explanations and examples of the Coriolis and centrifugal forces. The page incorporates many diagrams and links to other similar examples to explore. This is part of the HyperPhysics Collection containing similar explanations of many areas of physics and astronomy.

Nave, Carl R.

2009-06-23

438

HyperPhysics: Color Force  

NSDL National Science Digital Library

This HyperPhysics webpage contains a description of "color force" and "color charge." These are concepts in the "quark model," which explains interactions of protons, neutrons, and other particles. Numerous links provide background information. This page is part of the HyperPhysics Collection--many short, illustrated pages on various areas of physics and astronomy.

Nave, Carl R.

2012-06-17

439

Periodic Forcing of Congenital Nystagmus  

NASA Astrophysics Data System (ADS)

Congenital nystagmus is an involuntary oscillation of the eyes, which is associated with reduced visual acuity. We recover periodic orbits from the eye movement recordings and then explore the possibility of using periodic forcing to stabilise the waveforms, so that the retinal image movement is minimised and visual acuity development can be enhanced in children.

Clement, Richard A.; Abadi, Richard V.; Broomhead, David S.; Whittle, Jonathon P.

2002-07-01

440

Force of an actin spring  

NASA Astrophysics Data System (ADS)

The acrosomal process of the horseshoe crab sperm is a novel mechanochemical molecular spring that converts its elastic stain energy to mechanical work upon the chemical activation by Ca2+. Twisted and bent, the initial state of the acrosomal bundle features a high degree of complexity in its structure and the energy is believed to be stored in the highly strained actin filaments as an elastic potential energy. When activated, the bundle relaxes from the coil of the highly twisted and bent filaments to its straight conformation at a mean velocity of 15um/s. The mean extension velocity increases dramatically from 3um/s to 27um/s when temperature of the medium is changed from 9.6C to 32C (respective viscosities of 1.25-0.75cp), yet it exhibits a very weak dependence on changes in the medium viscosity (1cp-33cp). These experiments suggest that the uncoiling of the actin spring should be limited not by the viscosity of the medium but by the unlatching events of involved proteins at a molecular level. Unlike the viscosity-limited processes, where force is directly related to the rate of the reaction, a direct measurement is required to obtain the spring force of the acrosomal process. The extending acrosomal bundle is forced to push against a barrier and its elastic buckling response is analyzed to measure the force generated during the uncoiling.

Shin, Jennifer; Mahadevan, L.; Matsudaira, Paul

2003-03-01

441

Raqs Media Collective Flash Force  

E-print Network

of light and divorcing these from the potent explosions that initially produced them. It is a historyRaqs Media Collective Flash Force: A Visual History of Might, Right and Light Perhaps the greatest for making facts visible. The history of the flash belongs to the century-long quest of finding pure sources

Canales, Jimena

442

Thrust Forces in Underwater Swimming  

Microsoft Academic Search

Instantaneous and mean static thrust levels were measured for eight underwater swimmers restrained in a submerged force platform. Swimming was examined barefoot and with two types of fins. The main beneficial effect of the fins was to eliminate the substantial negative thrust component associated with barefoot swimming. Higher maximal thrust outputs were achieved with curved fins than with straight-bladed ones.

Raymond A. Christianson; Gershon Weltman; Glen H. Egstrom

1965-01-01

443

Casimir Force - Neutral or Electrostatic?  

Microsoft Academic Search

Since Casimir, the attractive force between neutral metal surfaces separated by an evacuated gap has been attributed to the zero point energy (ZPE) of quantum mechanics. But the Casimir theory has difficulty in explaining how contact of neutral surfaces in micro electro-mechanical systems (MEMS) devices can cause permanent adhesion without the discharge of the build-up of static charge. A modified

T. V. Prevenslik

444

Radiative Forcing from Carbonaceous Emissions  

NASA Astrophysics Data System (ADS)

Black Carbon particles are emitted as primary particles from incomplete combustion process, such as fossil fuel and biomass burning. Organic carbon particles are released in the atmosphere both from primary emissions and secondary emission of gaseous compounds via condensation or gas phase oxidation of hydrocarbons. Black carbon aerosols absorb the solar radiation and induce positive forcing whereas organic matter aerosols reflect solar radiation and produce negative forcing. Direct radiative forcing at the top of the atmosphere (TOA) for black carbon aerosols from these two inventories comes out to be +0.33 W/m2 (GEIA) and +0.14 W/m2 (Bond et al. 2004) respectively. However, for organic matter aerosols, it is simulated as -0.44 W/m2 for GEIA and -0.11 W/m2 with the inventory of Bond et al. (2004). In the present study we have compared the annual global burden, aerosol optical depth (AOD) and direct radiative forcing of carbonaceous aerosols using two emission inventories with the help of the general circulation model of the Laboratoire de Météorologie Dynamique (LMD). Normalised difference plots clearly show that with GEIA inventory model simulates generally higher values carbonaceous aerosols which are far superior in some parts of the globe in comparison to the BOND emission inventory.

Fatima, H.; Sharma, O.; Upadhyaya, H.

2011-12-01

445

Nuclear Force from String Theory  

E-print Network

We compute nuclear force in a holographic model of QCD on the basis of a D4-D8 brane configuration in type IIA string theory. Repulsive core of nucleons is quite important in nuclear physics, but its origin has not been well-understood in strongly-coupled QCD. We find that string theory via gauge/string duality deduces this repulsive core at short distance between nucleons. Since baryons in the model are realized as solitons given by Yang-Mills instanton configuration on flavor D8-branes, ADHM construction of two instantons probes well the nucleon interaction at short scale, which provides the nuclear force quantitatively. We obtain, as well as a tensor force, a central force which is strongly repulsive as suggested in experiments and lattice results. In particular, the nucleon-nucleon potential V(r) (as a function of the distance) scales as 1/r^2, which is peculiar to the holographic model. We compare our results with one-boson exchange model using the nucleon-nucleon-meson coupling obtained in our previous paper (arXiv:0806.3122).

Koji Hashimoto; Tadakatsu Sakai; Shigeki Sugimoto

2009-01-28

446

Gender Interactions with the Force  

E-print Network

differences on original FCI by gender Context an issue? Changing context = changing responses Conclusions differently FCI serving men and women equally? Originally tested on high school students at a time when mostGender Interactions with the Force Concept Inventory Laura McCullough University of Wisconsin

Wu, Mingshen

447

Atomic Force Microscope (Veeco Nanoman)  

E-print Network

Atomic Force Microscope (Veeco Nanoman) User Manual ­ Basic Operation 4th Edition Aug 2012 NR #12 the operating mode. Choose TappingMode by selecting: · Tapping in Air NRF.wks · Click on Scan on the AFM head. · Adjust the Vertical Deflection to 0 V Laser spot #12;Mounting the Sample · There are two

Subramanian, Venkat

448

The effect of occlusal forces on restorations.  

PubMed

This review will focus on the effect occlusal forces, both normal masticatory force and paranormal bruxing and clenching force, have on various restorative materials and their interaction with the teeth through a variety of bonding mechanisms. Salient physical properties of each of the materials will be reviewed, as well as the effect occlusal force has on restoration durability. PMID:23346657

Larson, Thomas D

2012-01-01

449

The effect of occlusal forces on restorations.  

PubMed

This review will focus on the effect occlusal forces, both normal masticatory force and paranormal bruxing and clenching force, have on various restorative materials and their interaction with the teeth through a variety of bonding mechanisms. Salient physical properties of each of the materials will be reviewed, as well as the effect occlusal force has on restoration durability. PMID:25318197

Larson, Thomas D

2014-09-01

450

May the Force Be with You!  

ERIC Educational Resources Information Center

Students have a difficult time understanding force, especially when dealing with a moving object. Many forces can be acting on an object at the same time, causing it to stay in one place or move. By directly observing these forces, students can better understand the effect these forces have on an object. With a simple, student-built device called…

Young, Timothy; Guy, Mark

2011-01-01

451

Titan Tusk Force Student Engagement Report  

E-print Network

Titan Tusk Force Student Engagement Report FY 2009-2010 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

de Lijser, Peter

452

Titan Tusk Force Student Engagement Report  

E-print Network

Titan Tusk Force Student Engagement Report FY 2008-2009 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

de Lijser, Peter

453

Titan Tusk Force Student Engagement Report  

E-print Network

Titan Tusk Force Student Engagement Report FY 2010-2011 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force (TTF) functions

de Lijser, Peter

454

Titan Tusk Force Student Engagement Report  

E-print Network

Titan Tusk Force Student Engagement Report FY 2012-2013 Mission Statement The mission of Titan Tusk Force is to develop a strong sense of campus unity, pride and identity with CSUF. Titan Tusk Force, CSUF, Incorporated here at California State University, Fullerton. Program Overview Titan Tusk Force

de Lijser, Peter

455

NTNU Java: Free-Body Force Diagram  

NSDL National Science Digital Library

This applet illustrates the forces on a block on an inclined plane. A free-body diagram shows the gravitational, normal, frictional and net force vectors. The weight, angle of the plane, and coefficient of friction can be changed by the user. The user can also apply an external force to the block. The motion resulting from the forces is not shown.

Hwang, Fu-Kwun

2005-02-07

456

Effective Forces Between Colloidal Particles  

NASA Technical Reports Server (NTRS)

Colloidal suspensions have proven to be excellent model systems for the study of condensed matter and its phase behavior. Many of the properties of colloidal suspensions can be investigated with a systematic variation of the characteristics of the systems and, in addition, the energy, length and time scales associated with them allow for experimental probing of otherwise inaccessible regimes. The latter property also makes colloidal systems vulnerable to external influences such as gravity. Experiments performed in micro-ravity by Chaikin and Russell have been invaluable in extracting the true behavior of the systems without an external field. Weitz and Pusey intend to use mixtures of colloidal particles with additives such as polymers to induce aggregation and form weak, tenuous, highly disordered fractal structures that would be stable in the absence of gravitational forces. When dispersed in a polarizable medium, colloidal particles can ionize, emitting counterions into the solution. The standard interaction potential in these charged colloidal suspensions was first obtained by Derjaguin, Landau, Verwey and Overbeek. The DLVO potential is obtained in the mean-field linearized Poisson-Boltzmann approximation and thus has limited applicability. For more precise calculations, we have used ab initio density functional theory. In our model, colloidal particles are charged hard spheres, the counterions are described by a continuum density field and the solvent is treated as a homogeneous medium with a specified dielectric constant. We calculate the effective forces between charged colloidal particles by integrating over the solvent and counterion degrees of freedom, taking into account the direct interactions between the particles as well as particle-counterion, counterion-counterion Coulomb, counterion entropic and correlation contributions. We obtain the effective interaction potential between charged colloidal particles in different configurations. We evaluate two- and three-body forces in the bulk as well as study the influence of soft walls. We qualitatively explain the effects of the walls on the forces and demonstrate that many-body effects are negligible in our system. With adjustments in the parameters, the DLVO pair-potential can describe the results quantitatively. Besides electrostatic interactions, entropic depletion effects that arise from (hard-core) exclusion play an important role in determining the behavior of multi-component colloidal suspensions. A standard theory for depletion forces is due to Asakura and Oosawa and is based on the ideal gas approximation. To go beyond this approximation, we have studied entropic forces in molecular dynamics simulations of systems of hard spheres (the effects of the solvent have been ignored). The effective depletion forces for these systems can be found either from equilibrium distribution functions or from direct momentum transfer calculations. Our results obtained by either method show qualitative differences from the Asakura-Oosawa forces, indicating a longer range, higher value at contact and most importantly a more complicated structure, comprising of several maxima and minima. Our calculations include the determination of effective forces between two spheres, a hard sphere and a wall, and the behavior of a hard sphere near a step-edge and a corner. We also demonstrate that such entropic forces do not necessarily satisfy pairwise additivity.

Tehver, Riina; Banavar, Jayanth R.; Koplik, Joel

1999-01-01

457

Child labor issues in the international setting.  

PubMed

Internationally, children are working in situations where there are exposures to many occupational hazards, lack of basic worker rights and, sometimes, forced employment. Many of the child workers are involved in family-based agriculture, cattle tending, crop harvesting, commercial plantation work, and the cleaning and packing of food. Many severe forms of child labor are found in the commercial agriculture of Latin America and the Caribbean. The International Labor Organization states that "few human abuses are so unanimously condemned, while being so widely practiced as child labor...working children, all over the world, deserve better". PMID:19785220

Osorio, Ana Maria

2004-01-01

458

Assessor Training International  

E-print Network

NVLAP Assessor Training International Arrangements #12;Assessor Training 2009: International;Assessor Training 2009: International Arrangements 3 2009 is the 10th anniversary of the signing granted by a signatory to the ILAC Arrangement #12;Assessor Training 2009: International Arrangements 4

459

An accurate ab initio quartic force field for ammonia J. M. L. Martin*) and Timothy J. Lee  

E-print Network

, and combustion studies, presupposes the availability of anharmonic force fields.' Third, dynam- ics studies would be the kinetics of the "thermal de- NOx" reaction4 in which the NOx emission of a jet engine of symmetry-unique and nonvanishing internal coordinate force constants to be de- termined. Even the harmonic

Martin, Jan M.L.

460

Calculation of rotordynamic forces on labyrinth seals  

E-print Network

whirling rotor and the fluid forces acting on it Resulting streamlines due to leakage flow in a labyrinth seal Geometry of an eccentric labyrinth seal An example of a finite difference grid in the eccentric region of the seal The modified bipolar... of the turbomachine which generates these forces is the labyrinth seal. Figure I illustrates the seal force components acting on an eccentric rotor. The leakage How through a labyrinth seal produces this net imbalance of forces. These forces cause the rotor...

Hensel, Steve John

2012-06-07