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Journal articles on the topic 'Weak force'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Robson, B. A. "Weak nuclear force." Modern Physics Letters A 36, no. 10 (February 18, 2021): 2130009. http://dx.doi.org/10.1142/s0217732321300093.

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This paper presents a critical historical review of the two main approaches to providing an understanding of the nature of the weak nuclear force via the Standard Model and the Generation Model of particle physics. The Standard Model is generally considered to be incomplete in the sense that it provides little understanding of several empirical observations: the Generation Model was developed to overcome several dubious assumptions made during the development of the Standard Model. This paper indicates that the Generation Model provides a more consistent understanding of the weak nuclear force than the earlier Standard Model.

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2

Meinert, Cornelia, and Uwe Meierhenrich. "Photochirogenesis versus Weak Force." Physics of Life Reviews 8, no. 3 (October 2011): 337–38. http://dx.doi.org/10.1016/j.plrev.2011.09.001.

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3

Fermani, R., S. Mancini, and P. Tombesi. "Entanglement assisted weak force detection." Fortschritte der Physik 52, no. 11-12 (November 1, 2004): 1110–17. http://dx.doi.org/10.1002/prop.200410181.

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4

Trócsányi, Zoltán. "Super-Weak Force and Neutrino Masses." Symmetry 12, no. 1 (January 6, 2020): 107. http://dx.doi.org/10.3390/sym12010107.

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We consider an anomaly free extension of the standard model gauge group G SM by an abelian group to G SM ⊗ U ( 1 ) Z . The condition of anomaly cancellation is known to fix the Z-charges of the particles, but two. We fix one remaining charge by allowing for all possible Yukawa interactions of the known left-handed neutrinos and new right-handed ones that obtain their masses through interaction with a new scalar field with spontaneously broken vacuum. We discuss some of the possible consequences of the model.

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5

Jones, John P. "Advertising: Strong Force or Weak Force? Two Views an Ocean Apart." International Journal of Advertising 9, no. 3 (January 1990): 233–46. http://dx.doi.org/10.1080/02650487.1990.11107151.

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6

Chandra, Kapil. "Why Gravity a Weak Force of Nature." Journal of High Energy Physics, Gravitation and Cosmology 06, no. 03 (2020): 353–56. http://dx.doi.org/10.4236/jhepgc.2020.63028.

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7

Knowles, Emily, and Jahara Matisek. "Western Security Force Assistance in Weak States." RUSI Journal 164, no. 3 (April 16, 2019): 10–21. http://dx.doi.org/10.1080/03071847.2019.1643258.

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8

Gould, C. R. "Neutron optical activity and the weak force." American Journal of Physics 65, no. 12 (December 1997): 1213–17. http://dx.doi.org/10.1119/1.18761.

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9

Burgess, C. P., and J. Cloutier. "Astrophysical evidence for a weak new force?" Physical Review D 38, no. 10 (November 15, 1988): 2944–50. http://dx.doi.org/10.1103/physrevd.38.2944.

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10

Bertrand, Anne Martine, Catherine Mercier, Priscilla Lam Wai Shun, Daniel Bourbonnais, and Johanne Desrosiers. "Effects of Weakness on Symmetrical Bilateral Grip Force Exertion in Subjects With Hemiparesis." Journal of Neurophysiology 91, no. 4 (April 2004): 1579–85. http://dx.doi.org/10.1152/jn.00597.2003.

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It has been shown that, in a bilateral force-matching task, subjects presenting weakness in one limb produce a lower force in the weakened limb even though they subjectively perceive that they are exerting the same force. The aim of this study was to verify whether subjects with hemiparesis produced asymmetrical forces during a bilateral submaximal grip task and whether this asymmetry is related to weakness of the paretic limb. Fifteen subjects with hemiparesis and 15 healthy subjects were recruited. First, the maximal voluntary force was measured for each hand. Then, subjects were asked to exert equal forces with both hands simultaneously at three submaximal force levels using two dynamometers. In the bilateral task, the force ratios (paretic/nonparetic or nondominant/dominant) differed between groups. Severely weak hemiparetic subjects produced lower force ratios than mildly weak hemiparetic subjects and healthy subjects ( P < 0.000), whereas there was no difference between the force ratios produced by mildly weak hemiparetic subjects and those produced by healthy subjects. In subjects with hemiparesis, the force ratios in the bilateral task were related to the ratios of maximal voluntary forces ( R2 = 0.39–0.66, P ≤ 0.013) and the presence of somatosensory impairment did not affect these relationships. These results suggest that the strategy used is to compare the intensity of the motor commands on both sides and then perform the force-matching task. The use of such a strategy by subjects who have had paresis for 1 year reflects a lack of adaptation to their weakness.

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11

Wang, Z. H., Jun Tan Yuan, X. Q. Hu, and X. W. Xiong. "Study on Cutting Forces in High-Speed Milling of LF21 Aluminum Alloy and Regression Model of Cutting Forces." Advanced Materials Research 69-70 (May 2009): 413–17. http://dx.doi.org/10.4028/www.scientific.net/amr.69-70.413.

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Cutting force is a key factor influencing the machining deformation of weak rigidity workpieces. In order to reduce the machining deformation and improve the process precision and the surface quality, it is necessary to study the factors influencing the cutting force and build the regression model of cutting forces. Firstly, the cutting parameters influencing cutting force are analyzed for LF21. Secondly, how certain cutting parameter influence the cutting component forces (Fx, Fy, Fz) are studied by the correlation analysis and the approach to choosing the right cutting parameters for machining the weak rigidity workpieces are presented. Finally, the regression model of cutting forces based on the cutting parameters is investigated in this paper.

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12

Shin, Yong Dal, and Myung Jin Chung. "An optimal force distribution scheme for cooperating multiple robot manipulators." Robotica 11, no. 1 (January 1993): 49–59. http://dx.doi.org/10.1017/s0263574700015435.

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SUMMARYIn this paper, we suggest an optimal force distribution scheme by weak point force minimization and we also present an efficient method to solve the problem. The concept of a weak point is a generalized one which is applicable to any points of interest, as well as joints or contact points between end-effectors and an object. The problem is formulated by a quadratic objective function of the forces exerted at weak points subject to the linear equality and inequality constraints, and its optimal solution is obtained by an efficient method. As regards the solution of the problem, the original problem is reformulated to a reduced order dual problem after the equality constraints are eliminated by force decomposition.

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13

Amorim, Heraldo J., and Augusto O. Kunrath Neto. "Study of the Relationship between Cutting Speed, Tool Wear and Machining Forces in Turning with Carbide Tool." Advanced Materials Research 902 (February 2014): 88–94. http://dx.doi.org/10.4028/www.scientific.net/amr.902.88.

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The understanding of machining processes comprises the study of phenomena such as: chip formation, cutting forces, tool wear mechanisms and the influence of the cutting parameters and machined materials on them. The aim of this work is to analyze the tool wear effects on machining forces during machining of AISI 1040 and 1045 carbon steels with carbide tool. Long-term machinability tests were performed, in which cutting force, feed force and tool wear were measured. Tool life results were analyzed, with best tool lives found for the AISI 1040 steel for all tested speeds. The other variables were analyzed as function of both time and tool wear. On the time domain, strong dependencies were found for both materials for tool wear, cutting force and feed force. The relationship between cutting force and tool wear showed good correlation for both materials, and the same was observed for feed force and tool wear relationship. Weak influence of cutting speed was observed on the relationship between tool wear and machining forces, which suggest that a single equation can describe them for all studied conditions with reasonable accuracy. The regression results are able to predict cutting forces as a function of tool wear with an average error of about 2.6 % during machining of AISI 1040 and 5.2 % for AISI 1045 steel. For the prediction of feed force as a function of tool wear, the average error is about 5.6 % for AISI 1040 and 7.0 % for the AISI 1045 steel, since a restricted domain is established. Data analysis showed a discontinuity in the behavior of feed force as a function of tool wear near the end of the life of the tools for most tests performed with AISI 1045 and some tests with AISI 1040 that suggest backwall wear, which was further evidenced by sudden change of chip form near the end of tool life in AISI 1040 steel.

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14

M Fleming, Richard, Matthew R Fleming, and Tapan K Chaudhuri. "Fleming Proposition: Gravity is Actually “Weak” Electromagnetic Force." Acta Scientific Pharmaceutical Sciences 3, no. 7 (June 26, 2019): 130. http://dx.doi.org/10.31080/asps.2019.03.0325.

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15

Mineo, Placido, Valentina Villari, Emilio Scamporrino, and Norberto Micali. "Supramolecular chirality induced by a weak thermal force." Soft Matter 10, no. 1 (2014): 44–47. http://dx.doi.org/10.1039/c3sm52322e.

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16

Betz, T., D. Koch, Y. B. Lu, K. Franze, and J. A. Kas. "Growth cones as soft and weak force generators." Proceedings of the National Academy of Sciences 108, no. 33 (August 3, 2011): 13420–25. http://dx.doi.org/10.1073/pnas.1106145108.

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17

Alvis, Jason. "Justice in Eros: Jacques Derrida’s Undeconstructible Weak Force." International Journal of the Humanities: Annual Review 9, no. 9 (2012): 167–78. http://dx.doi.org/10.18848/1447-9508/cgp/v09i09/43338.

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18

Langacker, Paul, and Alfred K. Mann. "The Unification of Electromagnetism with the Weak Force." Physics Today 42, no. 12 (December 1989): 22–31. http://dx.doi.org/10.1063/1.881185.

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19

Naghshineh, K., and G. H. Koopmann. "An Active Control Strategy for Achieving Weak Radiator Structures." Journal of Vibration and Acoustics 116, no. 1 (January 1, 1994): 31–37. http://dx.doi.org/10.1115/1.2930393.

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A general control strategy is presented for active suppression of total radiated sound power from harmonically excited structures based on the measurement of their response. Using the measured response of the structure together with knowledge of its structural mobility, an equivalent primary excitation force is found at discrete points along the structure. Using this equivalent primary force and performing a quadratic optimization of the power radiated from the structure, a set of control forces is found at selected points on the structure that results in minimum radiated sound power. A numerical example of this strategy is presented for a simply supported beam in a rigid baffle excited by a harmonic plane wave incident at an oblique angle. A comparison of the response of the beam with and without control forces shows a large reduction in the controlled response displacement magnitude. In addition, as the result of the action of the control forces, the magnitude of the wave number spectrum of the beam’s response in the supersonic region is decreased substantially. The effect of the number and location of the actuators on reductions in sound power level is also studied. The actuators located at the anti-nodes of structural modes within the supersonic region together with those lcoated near boundaries are found to be the most effective in controlling the radiation of sound from a structure.

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20

Tajik, F., N. Allameh, A. A. Masoudi, and G. Palasantzas. "Nonlinear actuation of micromechanical Casimir oscillators with topological insulator materials toward chaotic motion: Sensitivity on magnetization and dielectric properties." Chaos: An Interdisciplinary Journal of Nonlinear Science 32, no. 9 (September 2022): 093149. http://dx.doi.org/10.1063/5.0100542.

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We have investigated the dynamical actuation of micro-electromechanical systems under the influence of attractive and repulsive Casimir forces between topological insulator plates as a function of their dielectric function and coating magnetization. The analysis of the Casimir force in the limit of strong and weak magnetization shows that the attractive force, which is produced for plate magnetizations in the same direction, is greater than the repulsive force that is produced for opposite magnetizations. However, both forces remain comparable for intermediate magnetizations. Moreover, for weak magnetization, the attractive force becomes stronger for an increasing dielectric function, while the opposite occurs for the repulsive force. On the other hand, increasing magnetization decreases the influence of the dielectric function on both the repulsive and attractive forces. Furthermore, for conservative systems, bifurcation and phase portrait analysis revealed that increasing magnetization decreases the regime of stable operation for devices with attractive forces, while their operation remains always stable under the presence of repulsive forces. Finally, for non-conservative periodically driven systems, the Melnikov function and Poincaré portrait analysis show that for magnetizations in the same direction leading to strong attractive Casimir forces, chaotic motion toward stiction is highly likely to occur preventing the long-term prediction of actuating dynamics. A remedy for this situation is obtained by the application of any magnetization in opposite directions between the interacting surfaces since the repulsive force makes it possible to prevent stiction.

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21

Sun, Jian, Junwei Chen, Erfan Mohagheghian, and Ning Wang. "Force-induced gene up-regulation does not follow the weak power law but depends on H3K9 demethylation." Science Advances 6, no. 14 (April 2020): eaay9095. http://dx.doi.org/10.1126/sciadv.aay9095.

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Mechanical forces play important roles in development, physiology, and diseases, but how force is transduced into gene transcription remains elusive. Here, we show that transcription of transgene DHFR or endogenous genes egr-1 and Cav1 is rapidly up-regulated in response to cyclic forces applied via integrins at low frequencies but not at 100 Hz. Gene up-regulation does not follow the weak power law with force frequency. Force-induced transcription up-regulation at the nuclear interior is associated with demethylation of histone H3 lysine-9 trimethylation (H3K9me3), whereas no transcription up-regulation near the nuclear periphery is associated with H3K9me3 that inhibits Pol II recruitment to the promoter site. H3K9me3 demethylation induces Pol II recruitment and increases force-induced transcription of egr-1 and Cav1 at the nuclear interior and activates mechano-nonresponsive gene FKBP5 near the nuclear periphery, whereas H3K9me3 hypermethylation has opposite effects. Our findings demonstrate that rapid up-regulation of endogenous mechanoresponsive genes depends on H3K9me3 demethylation.

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22

Sherbon, Michael. "Fundamental physics and the fine-structure constant." International Journal of Physical Research 5, no. 2 (August 17, 2017): 46. http://dx.doi.org/10.14419/ijpr.v5i2.8084.

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From the exponential function of Euler’s equation to the geometry of a fundamental form, a calculation of the fine-structure constant and its relationship to the proton-electron mass ratio is given. Equations are found for the fundamental constants of the four forces of nature: electromagnetism, the weak force, the strong force and the force of gravitation. Symmetry principles are then associated with traditional physical measures.

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23

Тимощук, К. И., М. М. Халисов, В. А. Пеннияйнен, Б. В. Крылов, and А. В. Анкудинов. "Исследование механических характеристик нативных фибробластов с помощью атомно-силового микроскопа." Письма в журнал технической физики 45, no. 18 (2019): 44. http://dx.doi.org/10.21883/pjtf.2019.18.48238.17878.

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It was found that living fibroblasts become more rigid after exposure to colchicine. For reliable measurements, we identified the cells, that during indentation interact with weak lateral forces that do not distort the normal force contribution. The atomic force microscopy data of the mechanical characteristics of such cells are interpreted unambiguously.

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24

BRECHET, SYLVAIN D., ALEXANDRE ROULET, and JEAN-PHILIPPE ANSERMET. "MAGNETOELECTRIC PONDEROMOTIVE FORCE." Modern Physics Letters B 27, no. 21 (August 11, 2013): 1350150. http://dx.doi.org/10.1142/s0217984913501509.

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The dynamics of a system consisting of a matter continuum with a weak linear magnetoelectric coupling interacting with electromagnetic fields is examined on a local scale in a nonrelativistic limit. A consistent expression for the internal energy of the system is derived. The internal energy density and the continuity equation for the momentum lead to the derivation of ponderomotive forces. A nonuniform magnetoelectric coupling generates a "magnetoelectric" ponderomotive force that could be distinguished from the purely electric or magnetic ponderomotive forces by applying alternating electric and magnetic fields at distinct frequencies.

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25

He, Li Qun, Ping Wu, Zi Da Li, and Li Li Feng. "Dynamics for Dense Packing of Colloids." Advanced Materials Research 465 (February 2012): 248–54. http://dx.doi.org/10.4028/www.scientific.net/amr.465.248.

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Colloidal packing by evaporation is a process that particles are packed by Stokes’ forces. As particles are far from each other, interactions among them are too weak to be taken into account and it’s the Stokes’ force on free particles that is in charge of packing. However, when they are close to some extent, the force is countered by particle interactions. Here, with the aid of force balance model, we demonstrate that the further packing is achieved by all drag forces of particles in the upstream.

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26

Gong, Beili, Daoyi Dong, and Wei Cui. "Weak-force sensing in optomechanical systems with Kalman filtering." Journal of Physics A: Mathematical and Theoretical 54, no. 16 (March 26, 2021): 165301. http://dx.doi.org/10.1088/1751-8121/abe888.

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27

Zvezdin, A. K., and K. A. Zvezdin. "Magnus force and magnetic vortex dynamics in weak ferromagnets." Bulletin of the Lebedev Physics Institute 37, no. 8 (August 2010): 240–47. http://dx.doi.org/10.3103/s1068335610080038.

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28

黄, 政东. "The Research on Relationship between Neureinos and Weak Force." Modern Physics 07, no. 05 (2017): 197–212. http://dx.doi.org/10.12677/mp.2017.75023.

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29

Corney, J. F., G. J. Milburn, and Weiping Zhang. "Weak-force detection using a double Bose-Einstein condensate." Physical Review A 59, no. 6 (June 1, 1999): 4630–35. http://dx.doi.org/10.1103/physreva.59.4630.

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30

Gao, Jiabin, Mohan M. Bhadbhade, and Roger Bishop. "Multimolecular Weak-Force Tectons and Their Alternative Clathrate Forms." Crystal Growth & Design 20, no. 6 (April 30, 2020): 3701–12. http://dx.doi.org/10.1021/acs.cgd.9b01685.

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31

Consoli, M. "A weak, attractive, long-range force in Higgs condensates." Physics Letters B 541, no. 3-4 (August 2002): 307–13. http://dx.doi.org/10.1016/s0370-2693(02)02236-0.

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32

Hahn, C., T. Matsuyama, U. Merkt, and R. Wiesendanger. "Nanofabrication of weak links based on scanning force methods." Applied Physics A Materials Science & Processing 62, no. 3 (March 1996): 289–92. http://dx.doi.org/10.1007/bf01575097.

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33

Migliore, Juan, and Fabrizio Zanello. "The Hilbert functions which force the Weak Lefschetz Property." Journal of Pure and Applied Algebra 210, no. 2 (August 2007): 465–71. http://dx.doi.org/10.1016/j.jpaa.2006.10.003.

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34

Hahn, C., T. Matsuyama, U. Merkt, and R. Wiesendanger. "Nanofabrication of weak links based on scanning force methods." Applied Physics A: Materials Science & Processing 62, no. 3 (February 27, 1996): 289–92. http://dx.doi.org/10.1007/s003390050301.

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35

Xie, Li-Mei, Zhu-Cheng Zhang, Qin Wu, Zhi-Ming Zhang, and Ya-Fei Yu. "The weak Coulomb force estimation via an optomechanical system." Journal of Physics B: Atomic, Molecular and Optical Physics 53, no. 10 (May 1, 2020): 105401. http://dx.doi.org/10.1088/1361-6455/ab7c3d.

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36

Cao, Chuqi. "The kinetic Fokker–Planck equation with weak confinement force." Communications in Mathematical Sciences 17, no. 8 (2019): 2281–308. http://dx.doi.org/10.4310/cms.2019.v17.n8.a9.

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37

Gong, Xiang-jun, Xiao-chen Xing, Xiao-ling Wei, and To Ngai. "Direct measurement of weak depletion force between two surfaces." Chinese Journal of Polymer Science 29, no. 1 (August 26, 2010): 1–11. http://dx.doi.org/10.1007/s10118-010-1012-8.

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38

Hrouzek, Michal, Alina Voda, Martin Stark, and Joël Chevrier. "MODEL OF THE CANTILEVER USED AS A WEAK FORCE SENSOR IN ATOMIC FORCE MICROSCOPY." IFAC Proceedings Volumes 38, no. 1 (2005): 333–38. http://dx.doi.org/10.3182/20050703-6-cz-1902.00056.

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39

LEU, TZONG-SHYNG, JENG-REN CHANG, and CHUN-LIN KUO. "EXPERIMENTAL INVESTIGATION OF SLENDERNESS EFFECT ON SIDE FORCE OF SLENDER BODY." Modern Physics Letters B 24, no. 13 (May 30, 2010): 1413–16. http://dx.doi.org/10.1142/s021798491002375x.

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This study investigates side force of a slender body with slenderness from 4.4 to 8.0. The experimental results show that flow over a slender body experiences a significant side force at angle-of-attack (AOA) higher than 30°. The side force reaches its maximum at AOA ≈ 50°. The present study demonstrates that slenderness (L/D) produces obvious influence on sectional side force distribution at high AOA. To understand the mechanism, evolution of near-wall vortex structure is investigated via hot wire and surface pressure measurements. It was found that one strong vortex is situated close to body surface and the other weak vortex away from the body, inducing a significant side force. Because the weak vortex lifts off early, a new vortex forms in near-wall region. Formation and evolution of the new vortex is the major mechanism that causes local sectional side force distribution exhibiting a wavy form with an alternating sign along the body. Therefore, overall side force does not necessarily increase with increasing slenderness. Reducing overall side force by canceling the alternating vortex-induced forces over the body surface is found if the slenderness L/D > 6.8 at AOA > 40°.

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40

Jowsey, Aden, and Matt Visser. "Counterexamples to the Maximum Force Conjecture." Universe 7, no. 11 (October 27, 2021): 403. http://dx.doi.org/10.3390/universe7110403.

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Dimensional analysis shows that the speed of light and Newton’s constant of gravitation can be combined to define a quantity F*=c4/GN with the dimensions of force (equivalently, tension). Then in any physical situation we must have Fphysical=fF*, where the quantity f is some dimensionless function of dimensionless parameters. In many physical situations explicit calculation yields f=O(1), and quite often f≤1/4. This has led multiple authors to suggest a (weak or strong) maximum force/maximum tension conjecture. Working within the framework of standard general relativity, we will instead focus on idealized counter-examples to this conjecture, paying particular attention to the extent to which the counter-examples are physically reasonable. The various idealized counter-examples we shall explore strongly suggest that one should not put too much credence into any truly universal maximum force/maximum tension conjecture. Specifically, idealized fluid spheres on the verge of gravitational collapse will generically violate the weak (and strong) maximum force conjectures. If one wishes to retain any truly general notion of “maximum force” then one will have to very carefully specify precisely which forces are to be allowed within the domain of discourse.

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41

Hou, Yu, Ming Zhang, and Hong Nie. "Analysis of Sensitive Parameters Affecting Unlocking Force of Finger Lock in Landing Gear." International Journal of Aerospace Engineering 2021 (January 13, 2021): 1–19. http://dx.doi.org/10.1155/2021/6652056.

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The mechanical characteristics of the unlocking force of the landing gear finger lock were studied in this paper, the influence of its diameter, fingertip angle, wear, and other factors on the unlocking force in one complete working cycle was analyzed, and the sensitive parameters that affect the unlocking force were obtained. Firstly, the unlocking force and wear of finger lock were calculated theoretically, and the changing rule of the unlocking force and wear with each parameter was obtained. Then, the validity of the correlation coefficient and model was verified by experiment. Finally, combined with the effective coefficient obtained from the experiment, the Archard wear model was used to simulate the change rule of lock force. The results show that in one complete working cycle, the inner surface diameter is negatively related to the unlocking force, fingertip diameter has little effect on the unlocking force, fingertip angle is negatively related to the unlocking force, and wear is positively related to the unlocking force; friction coefficient and fingertip angle are high sensitive parameters that affect the unlocking force, which have obvious effect on the unlocking force. The inner surface diameter, fingertip diameter of finger lock, and wear are the low sensitive parameters that affect the unlocking force, and the influence on the unlocking force is weak.

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42

EAMES, I., and J. C. R. HUNT. "Inviscid flow around bodies moving in weak density gradients without buoyancy effects." Journal of Fluid Mechanics 353 (December 25, 1997): 331–55. http://dx.doi.org/10.1017/s002211209700760x.

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We examine the inviscid flow generated around a body moving impulsively from rest with a constant velocity U in a constant density gradient, ∇ρ0, which is assumed to be weak in the sense ε=a[mid ]∇ρ0[mid ] /ρ0[Lt ]1, where a is the length scale of the body. In the absence of a density gradient (ε=0), the flow is irrotational and no force acts on the body. When 0<ε[Lt ]1, vorticity is generated by a baroclinic torque and vortex stretching, which introduce a rotational component into the flow. The aim is to calculate both the flow around the body and the force acting on it.When a two-dimensional body moves perpendicularly to the density gradient U·∇ρ0=0, the density and velocity field are both steady in the body's frame of reference and the vorticity field decays with distance from the body. When a three-dimensional body moves perpendicularly to the density gradient, the vorticity field is regular in the main flow region, [Dscr ]M, but is singular in a thin inner region [Dscr ]I located adjacent to the body and to the downstream-attached streamline, and the flow is characterized by trailing horseshoe vortices. When the body moves parallel to the density gradient U×∇ρ0=0, the density field is unsteady in the body's frame of reference; however to leading order the flow is steady in the region [Dscr ]M moving with the body for Ut/a[Gt ]1. In the thin region [Dscr ]I of thickness O(aε), the density gradient and vorticity are singular. When U×∇ρ0=0 this singularity leads to a downstream ‘jet’ with velocities of O(−(U·∇ρ0) Ua/(ρ0U)) on the downstream attached streamline(s). In the far field the flow is characterized by a sink of strength CM[Vscr ] (U·∇ρ0) /2ρ0, located at the origin, where CM is the added-mass coefficient of the body and [Vscr ] is the body's volume.The forces acting on a body moving steadily in a weak density gradient are calculated by considering the steady relative velocity field in region [Dscr ]M and evaluating the momentum flux far from the body. When U·∇ρ0=0, a lift force, CL[Vscr ] (U·∇ρ0)×U, pushes the body towards the denser fluid, where the lift coefficient is CL=CM/2 for a three-dimensional body, that is axisymmetric about U, and is CL=(CM+1)/2 for a two-dimensional body. The direction of the lift force is unchanged when U is reversed. A general expression for the forces on bodies moving in a weak shear and perpendicularly to a density gradient is calculated. When U×∇ρ0=0, a drag force −CD[Vscr ] (U·∇ρ0)U retards the body as it moves into denser fluid, where the drag coefficient is CD=CM/2, for both two- and three-dimensional axisymmetric bodies. The direction of the drag force changes sign when U is reversed. There are two contributions to the drag calculation from the far field; the first is from the wake ‘jet’ on the attached streamline(s) caused by the rotational component of the flow and this leads to an accelerating force. The second and larger contribution arises from a downstream density variation, caused by the distortion of the isopycnal surfaces by the primary irrotational flow, and this leads to a drag force.When cylinders or spheres move with a velocity U at arbitrary orientation to the density gradient, it is shown that they are acted on by a linear combination of lift and drag forces. Calculations of their trajectories show that they initially slow down or accelerate on a length scale of order ρ0/[mid ]∇ρ0[mid ] (independent of [Vscr ] and U) as they move into regions of increasing or decreasing density, but in general they turn and ultimately move parallel to the density gradient in the direction of increasing density gradient.

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43

Stilp, Fabian, Andreas Bereczuk, Julian Berwanger, Nadine Mundigl, Klaus Richter, and Franz J. Giessibl. "Very weak bonds to artificial atoms formed by quantum corrals." Science 372, no. 6547 (May 13, 2021): 1196–200. http://dx.doi.org/10.1126/science.abe2600.

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We explored the bonding properties of the quantum corral (a circle of 48 iron atoms placed on a copper surface) reported by Crommie et al. in 1993, along with variants, as an artificial atom using an atomic force microscope (AFM). The original corral geometry confines 102 electrons to 28 discrete energy states, and we found that these states can form a bond to the front atom of the AFM with an energy of about 5 millielectron volts. The measured forces are about 1/1000 of typical forces in atomically resolved AFM. The confined electrons showed covalent attraction to metal tips and Pauli repulsion to CO-terminated tips. The repulsion at close distance was evident from the response of corral states created by deliberately placing single iron atoms inside the corral. The forces scaled appropriately with a 24-atom corral.

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44

Vayenas, Constantinos G. "The Standard Model (SM) and the goal of force unification." Open Access Government 37, no. 1 (January 6, 2023): 228–31. http://dx.doi.org/10.56367/oag-037-10539.

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The Standard Model (SM) and the goal of force unification The unification of gravitational, Strong and Weak Forces has been a long-sought goal [1-3]. In general, force unification refers to the idea that it is possible to view all of the forces of nature as manifestations of one single, all-encompassing force. Today, within the context of the Standard Model (SM) of elementary particles, [7] scientists seek to unify Gravity with the Strong force under a Grand Unified Theory which binds quarks together and is responsible for the stability of atomic nuclei. These efforts have not been successful yet, most likely because the SM neglects neutrinos [8,9], gravity [4], special relativity [10] and quantum mechanics [11].

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45

Lu, Pengzhen, Jianting Chen, Jingru Zhong, and Penglong Lu. "Optimization Analysis Model of Self-Anchored Suspension Bridge." Mathematical Problems in Engineering 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/403962.

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The hangers of self-anchored suspension bridge need to be tensioned suitably during construction. In view of this point, a simplified optimization calculation method of cable force for self-anchored suspension bridge has been developed based on optimization theories, such as minimum bending energy method, and internal force balanced method, influence matrix method. Meanwhile, combined with the weak coherence of main cable and the adjacently interaction of hanger forces, a simplified analysis method is developed using MATLAB, which is then compared with the optimization method that consider the main cable's geometric nonlinearity with software ANSYS in an actual example bridge calculation. This contrast proves the weak coherence of main cable displacement and the limitation of the adjacent cable force influence. Furthermore, a tension program that is of great reference value has been developed; some important conclusions, advices, and attention points have been summarized.

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46

Kawakami, M., and D. A. Smith. "A new atomic force microscope force ramp technique using digital force feedback control reveals mechanically weak protein unfolding events." Nanotechnology 19, no. 49 (November 19, 2008): 495704. http://dx.doi.org/10.1088/0957-4484/19/49/495704.

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47

Sherbon, Michael A. "Golden Ratio Geometry and the Fine-Structure Constant." JOURNAL OF ADVANCES IN PHYSICS 16, no. 1 (October 22, 2019): 362–68. http://dx.doi.org/10.24297/jap.v16i1.8469.

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The golden ratio is found to be related to the fine-structure constant, which determines the strength of the electromagnetic interaction. The golden ratio and classical harmonic proportions with quartic equations give an approximate value for the inverse fine-structure constant the same as that discovered previously in the geometry of the hydrogen atom. With the former golden ratio results, relationships are also shown between the four fundamental forces of nature: electromagnetism, the weak force, the strong force, and the force of gravitation.

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48

Loper, David E. "On the motion of a rigid cylinder in a rotating electrically conducting fluid." Journal of Fluid Mechanics 260 (February 10, 1994): 299–314. http://dx.doi.org/10.1017/s0022112094003526.

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The flow structures generated and drag experienced by a rigid cylinder moving in an arbitrary direction through a rotating electrically conducting fluid in the presence of an applied magnetic field are investigated, with he aim of understanding better the nature of the small-scale flow in the core of the Earth which may be responsible for maintaining the geomagnetic field through dynamo action. Three cases are considered in the limit of small Rossby and magnetic Reynolds numbers. In the case of very weak rotation, the possible flow structures consist of a thin Hartmann layer and a long wake extending in the direction of the magnetic field, in which Lorentz and viscous forces balance, but only the long wake plays a dynamical role. The dominant drag force is experienced for motion that cuts magnetic lines of force. Motion of the cylinder parallel to its axis induces a much weaker drag, while that in the direction of the magnetic field induces none to dominant order. The cylinder also experiences weak lateral forces due to the Coriolis effect. In the case of weak rotation, the balance in the long wake is now magnetostrophic: between Lorentz and Coriolis forces. The drag is qualitatively identical to that in the first case, but the drag induced by motion parallel to the axis of the cylinder is increased, though still smaller than that for motions cutting magnetic lines of force. In the case of strong rotation, the flow structures consist of a thin Ekman layer and a foreshortened Taylor column extending in the direction of the rotation axis. In this column, the force balance is again magnetostrophic. Again only the large-scale structure plays a dynamical role. Motion of the cylinder perpendicular to its axis induces a larger drag than does motion parallel to its axis. The cylinder also experiences large lateral Coriolis forces.

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LINDENBERG, KATJA, J. M. SANCHO, M. KHOURY, and A. M. LACASTA. "WEAK DISORDER IN PERIODIC POTENTIALS: ANOMALOUS TRANSPORT AND DIFFUSION." Fluctuation and Noise Letters 11, no. 01 (March 2012): 1240004. http://dx.doi.org/10.1142/s0219477512400044.

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Particles driven through a periodic potential by an external constant force are known to exhibit a pronounced peak of the diffusion around the critical deterministic force that defines the transition between locked and running states. It has recently been shown both experimentally and numerically that this peak is greatly enhanced if some amount of spatial disorder is superimposed on the periodic potential. Here, we show that this enhancement is a fingerprint of a broad phenomenology that goes well beyond a simple augmentation. For some values of the model parameters, including the characteristic distances associated with the periodic and random components of the potential, the magnitude of the external force, and the temperature, the system can exhibit a rich variety of regimes from normal diffusion to superdiffusion, subdiffusion and even subtransport.

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50

Bohinc, Klemen, and Leo Lue. "A field theoretic approach to the electric interfacial layer — Mixture of trivalent rod-like and monovalent point-like ions between charged walls." Modern Physics Letters B 29, no. 32 (November 30, 2015): 1550202. http://dx.doi.org/10.1142/s0217984915502024.

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In this paper, we study the interaction between charged macroions (surfaces) immersed in a solution of oppositely charged, rod-like counterions and point-like co-ions. The system is modeled by a field theoretic approach, which was extended to treat mixtures of rod- and point-like ions. The theory is applicable from the weak to the intermediate through to the strong coupling regimes. In the weak coupling limit, the force between the charged surfaces are only repulsive. In the intermediate coupling regime, the rod-like ions can induce attractive force between the charged surfaces. In the strong coupling limit, the inter-ionic charge correlations dominate the attractive forces at short separations between the charged surfaces.

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