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1
Pierre, Thomas. "L'action en force et les forces en action : sociologie de la force au travail." Thesis, Metz, 2011. http://www.theses.fr/2011METZ012L/document.
Testo completoAbstract (sommario):
L’étude s’inscrit dans la continuité des travaux de la sociologie pragmatique concernant les régimes d’engagement dans l’action. Elle vise à compléter l’architecture des compétences au jugement et à l’action des personnes par la modélisation d’un régime d’action stratégique. Il s’agit d’étudier ce régime dans son économie interne et dans ses rapports avec d’autres régimes d’engagement en le considérant comme un appui pour dénoncer et justifier. L’enquête mobilise différentes ressources qui travaillent ensemble à la production des catégories de description et d’analyse. En premier lieu, l’étude s’appuie sur le corpus théorique de la sociologie pragmatique et de la sociologie de la dispute. Ensuite, c’est une lecture de l’œuvre de N.Machiavel entendue comme grammaire politique de l’action stratégique qui est activée. Enfin, deux enquêtes empiriques communiquent avec ces travaux. L’une concerne des dispositifs d’impartition logistique dans le commerce électronique aux particuliers. La seconde observe le travail de représentation d’une entreprise électorale en campagne.Le régime d’action stratégique est un principe de perception et de structuration des actions et des situations qui s’appuie sur un principe d’équivalence en puissance. Les situations sont constituées de rapports de force qui se nouent autour de biens à conserver ou acquérir. La mesure des situations comme des relations de puissance permet de réduire l’incertitude sur l’action à entreprendre, d’ordonner les situations et d’opérer une distribution des biens. La virtù est la compétence des personnes à l’action stratégique, elle leur permet de s’engager dans ces situations<br>This study falls within the focus of research on pragmatic sociology concerning engagement schemes of action. This thesis sets out to compliment the competence to judge and the actions by person through a strategic action regime modelisation system. This involves examining this regime within the internal economy and its relation with other schemes of engagement which can be considered as a resource to denounce and justify.This inquiry employs different resources which impact the production of different categories of analysis and description. First of all, the study is based on the body of theory in pragmatic sociology and disagreements postulated in sociology. Secondly, a focus on the work of N. Machiavelli, equated with political grammar of strategic action. Followed, by an analysis of two empirical surveys linked to the research themes treated. The first survey concerns the planning related to logistical sub-contracting in the electronical commercial domain. The second survey, analyses the work concerning the representation of an electoral enterprise campaign.The strategic action of regime is a lens to analyze and construct a framework of the actions and situations which are based on the principles of equity of power. The situations consist of power struggles aimed to keep or conserve that which is good. The evaluation of situations such as power relations facilitate the reduction of uncertainty in carrying out actions, in order to classify the situations and proceed to distribution of goods. Virtù refers to the competence of people in strategic actions which facilitate engagement in strategic situation
2
Guessoum, Ahlam. "Force exécutoire et obligation : essai sur l'exécution forcée en droit privé." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENA011.
Testo completoAbstract (sommario):
L'inexécution de l'obligation par le débiteur constitue un moment crucial dans la « vie » de l'obligation. La force de l'obligation à apporter des remèdes efficaces au créancier se pose avec le plus d'acuité à cet instant. Analyser l'obligation sous l'angle de son efficacité concrète conduit à un constat immédiat. La force obligatoire, omniprésente dans le régime de l'obligation, se voit attribuer une fonction dont l'effectivité est, pourtant, dans le contexte de l'inexécution, résiduelle. Inefficace, à cet instant, la force obligatoire ne saurait, en aucune manière, constituer le fondement de la sanction de l'obligation par l'exécution forcée. Mais, sans lui retirer toute utilité, la force obligatoire permet de causer le paiement spontané de l'obligation en dehors de tout conflit lié à l'exécution. En revanche, tant la définition de sanction que celle de contrainte évoquent la notion de force et d'exécutoire. La force exécutoire embrasse l'obligation dès lors qu'est entreprise l'obtention de son efficacité économique consécutivement au constat de son inexécution. La prise en compte de l'obligation dans le régime exécutoire invite à penser la notion de force exécutoire au-delà de son sens traditionnel : la force exécutoire ne se définit pas exclusivement comme une compétence. Ainsi, matérialisée dans un titre exécutoire, la force exécutoire est, et au delà d'une simple condition de ce titre, une force en rapport avec l'obligation. L'efficacité de la sanction de l'exécution forcée dépend entièrement de l'effectivité de la force exécutoire dont est assorti le titre exécutoire. Le titre exécutoire ne constitue pas un simple instrumentum assorti de la force probante des actes authentiques et de la formule exécutoire, il est aussi un negotium dont l'obligation exécutoire est un élément.Aucune exécution forcée ne peut être poursuivie en l'absence de titre exécutoire, aucun titre exécutoire ne peut être mis en oeuvre sans obligation exécutoire<br>The breach of duty by the debtor is a crucial moment in the "life" of the obligation. The force of the obligation to provide effective remedies to the creditor arises with the more acute at this time. Analyze the obligation in terms of its practical effectiveness leads to an immediate conclusion. The obligatory (or binding) force that permeates the system of obligation , is assigned a function whose effectiveness is , however, in the context of the failure , residual . Ineffective , at this moment, the binding force is not, in any way, the basis of assent required by enforcement . But without withdrawing this force any utility, binding force can cause spontaneous payment of the obligation without any conflict related to execution. However, both the definition of punishment that duress evoke the concept of force and enforceability. Enforceable obligation, therefore, appears when economic efficiency is searching consecutively to a finding of non-performance. Taking into account the obligation in its forceable systemen prompt to think the concept of enforceability beyond its traditional meaning : the enforceability is not defined exclusively as a skill. Thus, embodied in an enforceable act , enforceability is, and beyond a simple condition of this act, a force in relation to the obligation. The effectiveness of enforcement depends entirely on the effectiveness of the enforceability of which is attached to the writ of execution. The enforcement act is not a simple instrumentum matching the probative value of authentic instruments and its enforcement, but it is also a negotium, which enforcable obligation is an element.No execution can be implemented in the absence of enforceable , no enforceable act can be implemented without enforceable obligation
3
Anderson, Evan V. "Atomic Force Microscopy: Lateral-Force Calibration and Force-Curve Analysis." Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-theses/337.
Testo completoAbstract (sommario):
This thesis reflects two advances in atomic force microscopy. The first half is a new lateral force calibration procedure, which, in contrast to existing procedures, is independent of sample and cantilever shape, simple, direct, and quick. The second half is a high-throughput method for processing, fitting, and analyzing force curves taken on Pseudomonas aeruginosa bacteria in an effort to inspire better care for statistics and increase measurement precision.
4
Grover, Francis M. "Intermittency between grip force and load force." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522334274008361.
Testo completo
5
Saidani, Hariz. "La rupture du contrat." Thesis, Toulon, 2016. http://www.theses.fr/2016TOUL0101/document.
Testo completoAbstract (sommario):
Le contentieux contractuel éclate lorsque l'une des parties n'exécute plus ou pas ses obligations. La préoccupation essentielle en matière contractuelle, consiste à lutter contre une rupture abusive et arbitraire du contrat. La particularité du droit civil français en matière de rupture du contrat, est la place très importante qu'occupe le juge judiciaire. L'assurance de la protection des intérêts des parties et la garantie d'une sanction juste et équitable, reposent en effet, sur les épaules du juge. Il est par conséquent inconcevable que le juge soit écarté du jeu de la rupture contractuelle. L'orientation traditionnelle a toujours fait du juge un pilier dans le domaine de la séparation contractuelle, mais cette tendance commence quelque peu à se dissiper. Le juge doit toujours jouer un rôle très important en droit des contrats en général et dans sa rupture en particulier. Une protection efficace des parties donnerait à l'intervention du juge une utilité plus importante. Il est primordial, que le juge soit un acteur, en matière de rupture contractuelle, dont le rôle serait la garantie du respect des lois et la protection complète des parties ; le cas contraire, pourrait réduire alors la portée du code civil actuel à un simple catalogue de lois régissant l'anéantissement du contrat<br>Contractual litigation arises when one of the parties fails to fulfill its obligations. Its main concern is to fight against abusive and arbitrary breach of contracts. In the French civil law, the judge occupies a very important place when debating breach of contracts. It is impossible to alienate the judge when it comes down to contract breaches. In fact, he insures that the interests of every concerned party are protected. He also guarantees that fair and equitable sanctions will be applied. Traditionally, the judge was very important when discussing breach of contracts. However, this trend is beginning to dissipate. In general, the judge plays a very important role in contract law, but his role is primordial when disputing contract termination. Effective protection of the parties would give the intervention of the judge a greater utility. It is essential that the judge remains an important actor when it comes to breach of contract as his role is to guarantee that the law is respected and that every party is adequately protected. On the contrary, it could reduce the importance of the current Civil Code to a mere catalog of laws governing the annulment contracts
6
Crone, Joshua C. "Quantitative prediction of tip-sample repulsive forces and sample deformation in tapping-mode frequency and force modulation atomic force microscopy." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8741.
Testo completoAbstract (sommario):
Thesis (M.S.) -- University of Maryland, College Park, 2008.<br>Thesis research directed by: Dept. of Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
7
Ahmanson, Christus. "Unrelenting Force." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1254.
Testo completoAbstract (sommario):
The following is an original screenplay about Maturity set in the mode of a Summer Romance. It is structured like the classic Joseph Campbell Monomyth. However, it offers a commentary on the unchanging nature of people by utilizing non-linear storytelling and inverting the typical hero’s journey narrative by having the protagonist end up, more or less, where he began. Key moments and story beats are taken from classic hero’s journeys and refashioned to fit the scale and time periods. Collin Williams does not cross the threshold into a magical new land but instead into the fantastical realm of Rock and Roll, he does not vanquish his foe by the sword, and he does not save a beautiful maiden, but the story is structured so that these events are adapted into their more logical real world parallels. All the while he is tempted by his love interest Liz and belittled by the “too cool for school” Billy James. Characters are molded from universal archetypes including the sage, jester, warrior, and king. Each has an arc that illuminates how these one dimensional approaches to life come into conflict with maturity. The screenplay takes advantage of the multi-tiered method of storytelling unique to cinema through heavy and deliberate inclusion of specific sounds and music. Repeated visual motifs and symbols also feature prominently with references to other revered journeys of self discovery and lifestyle philosophies.
8
Schopper, Aaron W. "The effects of force level and force direction on force discrimination and isometric tracking performance." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/81043.
Testo completoAbstract (sommario):
An isometric, zero-order, two-dimensional pursuit tracking task utilizing a tracking path that incorporated both linear and circular segments was used to examine the effects of variation in force magnitude, force direction, and direction of target movement upon tracking performance. A contralateral force-matching procedure was also employed to assess the effects of variation in force level and force direction upon force discrimination capabilities.
Increases in force demand were hypothesized to result in degradation of both force discrimination capabilities and accuracy of tracking performance. Variation in force direction was hypothesized to result in tracking performance degradation and force discrimination deterioration that were inversely related to strength-related differences associated with each direction. It was hypothesized that linear tracking performance during inward (force-decreasing) movement of the target would be superior to linear tracking performance in the outward (force-increasing) direction. Finally, it was hypothesized that the direction-sensitive strength:demand ratio, SDR, (a measure of the relationship between strength and the magnitude of force demand) would correlate with both tracking performance and force discrimination measures and that force discrimination measures would correlate with tracking performance.
The findings robustly supported the hypothesized Force Level effect. The strength-related Force Direction effects were also supported, but somewhat less consistently than those for Force Level. As also hypothesized, linear inward tracking was superior to linear outward tracking. Previously unreported direction-of-movement effects were found for the circular tracking conditions. When measured along the path, clockwise (CW) tracking was superior to counterclockwise (CCW) tracking with the differences being greatest at the higher force level and in the longitudinal (forward and aft) directions. CCW tracking was superior to CW tracking when measured orthogonal to path. The hypothesized correlations among SDR, two of the three force discrimination measures, and tracking performance were found to be small but significant.<br>Ph. D.
9
Sweetman, Adam. "Forces at the nanoscale : interactions in atomic force microscopy and dielectrophoresis." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11213/.
Testo completoAbstract (sommario):
Interactions at the nanoscale are governed almost exclusively by electromagnetic forces, but the interplay between different scaling laws produces a vast array of behaviours. We investigate radically different systems spanning almost three orders of magnitude of length scales, and use a variety of experimental techniques to determine the forces present in each regime, and the interplay between them. An important prototypical surface in SPM science has been the Si(100) surface, which due to it’s unstable buckling and complex electronic structure has fostered considerable debate in the surface science community. We have used small amplitude, high sensitivity combined qPlus STM/AFM to investigate tip -- sample interactions on the Si(100) surface at low-temperature in UHV, with a focus on the chemical, and electronic properties of the system and how these are modified by the probe. We present the first atomic resolution combined force/tunnel current results on the surface and show that great care must be taken in interpreting either pure AFM or pure STM data. We also examine tip -- sample interactions on arrays of thiol passivated spin-cast nanoparticles in both UHV and ambient conditions and show for the first time how minor modifications to the experimental parameters can radically alter the data collected, most likely due to the thiol -- surface -- tip interaction. We also present SKPM and voltage spectroscopy of the same samples and show the importance of electrostatic interactions in correct height determination of these network arrays, in parallel with the caution that must be maintained in interpreting CPD data. A key mechanism for the manipulation of meso-scale objects in solution is Dielelectrophoresis, which offers strong material and size specificity and a high degree of spatial control. In the final experimental chapter we investigate the effect of inhomogenous electric fields on nanoparticles in aqueous solution, and reveal how previously uninvestigated electrochemical effects can become important even at high frequencies, and may offer a new and exciting route for the control of self organised nanowires in solution.
10
de, Mesa Winell. "Downsizing the United States Air Force Security Forces: A Phenomenological Investigation." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/351.
Testo completoAbstract (sommario):
The United States Air Force (USAF) has downsized an average of 10,000 active duty personnel each year from 1990 to 2010. Despite this downsizing, the mission remains the same, which increases the workload on the remaining airmen, lowers morale, decreases specialization, changes the mindset/culture, accelerates promotion rates, and shifts the dependence on technology in the Security Forces career field. The USAF needs adequately sized and proficient members to meet its mission. This phenomenological study examined the effects of USAF downsizing on the USAF Security Forces career field. The great man theory, social learning theory, theory of expertise, and Maslow's hierarchy of needs provided the conceptual framework. Semistructured interviews were gathered with a purposeful sample of 24 retired Security Forces members, near Air Combat Command bases; data were then analyzed through the Moustaukas modified van Kaam technique. The themes from this study were the cycle of downsizing; increased workload despite decreased number of personnel, also known as "more with less"; an accelerated promotion rate; and dependence on technology. The primary finding suggested the need for specialization and consistency of technology used. Further research on downsizing based on budgetary constraints, awareness of the loss of specializations after downsizing, and communication while downsizing could expand the findings of this study. The results of this study can be used by all leadership facing budgetary constraints and technology upgrades. Social change could ensue if leadership observes the cultural changes that occur when choosing to downsize and merge.
11
McKee, Clayton T. "Investigation of Non-DLVO Forces using an Evanescent Wave Atomic Force Microscope." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28233.
Testo completoAbstract (sommario):
This dissertation describes new methods for measuring surface forces using evanescent waves, and applications to non-DLVO forces. An evanescent wave, generated at a solid-liquid interface, is scattered by AFM tips or particles attached to AFM cantilevers. The scattering of this wave is used to determine absolute separation between surfaces and/or the refractive index as a function of separation in AFM measurements. This technique is known as evanescent wave atomic force microscopy (EW-AFM). The scattering of an evanescent wave by Si3N4 AFM tips is large and decays exponentially with separation from a refractive index boundary. Thus, scattering is a useful method for measuring the separation between a Si3N4 tip and sample. This method has been used to measure the absolute separation between a tip and sample in the presence of an irreversibly adsorbed polymer film. Measurement of the film thickness and time response of the polymer to applied loads has also been studied. These measurements are not possible using current AFM techniques. In addition to measurements in polymer systems, the simple scattering profile from Si3N4 tips was used to re-examine short range hydration forces between hydrophilic surfaces. Results presented in this thesis suggest this force does not depend on the hydrated radius of the ion between glass and silicon nitride. The scattering generated by a Si3N4 tip has also been used to measure the refractive index of bulk fluids and thin films between hydrophobic surfaces. Based on these results, I have shown that a long-range attraction between hydrophobic surfaces is accompanied by an increase in the refractive index between the tip and surface. From this I have concluded that the attractive force, measured in this study, is the result of an increase in the concentration of organic material between surfaces. Finally, I have shown that the scattering profile depends on the material and size of the scattering object. Scattering from silicon nitride tips is exponential with separation. In contrast, the scattering profile from silicon tips, which are similar in size and geometry, is not a simple exponential. The scattering profile of larger spherical particles attached to cantilevers is also not exponential. It is approximately the sum of two exponentials. The functional form of the scattering profile with separation is consistent with the transmission of evanescent light through flat planar films. This result would suggest that a re-examination of the separation-dependence of scattering in TIRM measurements is necessary.<br>Ph. D.
12
Grimble, Ralph Ashley. "Atomic force microscopy : atomic resolution imaging and force-distance spectroscopy." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312277.
Testo completo
13
Jackson, Cornelius Christiaan. "Tactile force-sensing for dynamic gripping using piezoelectric force- sensors." Thesis, Bloemfontein : Central University of Technology, Free State, 2009. http://hdl.handle.net/11462/34.
Testo completo
14
Nasca, David Stephen. "The All-Volunteer Force and Presidential Use of Military Force." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/94609.
Testo completoAbstract (sommario):
The creation of the All-Volunteer Force (AVF) in 1973 allowed U.S. presidents to deploy American military power in times and places of their own choosing with fewer concerns that the electorate would turn against their leadership. A reaction to the trauma of the Vietnam War, the AVF did away with conscription and instead relied on volunteers to serve and fight in U.S. military operations. The AVF's ranks were mostly filled with those willing to deploy and fight for their country, without the U.S. having to rely on conscription. When U.S. presidents had to use the AVF to fight in conflicts, they could expect to enjoy a higher degree of public support than those presidents who led the U.S. military during the Korean and Vietnam wars.
Drawing from casualty, financial, and public opinion statistics from 1949 through 2016, this thesis argues that with the adoption of the AVF in 1973 U.S. presidents have been better able to deploy the AVF in combat with less resistance from the American people. It examines the circumstances behind the creation of the AVF, looking second, at the deployment of the AVF from the Gulf War to the Global War on Terror to determine if U.S. presidents enjoyed popular support and were encouraged to rely on military force as the primary option in foreign policy. Finally, the study compares casualties, financial costs, and public support for conflicts relying on conscripted forces to those depending on the AVF to examine if U.S. presidents were better able to involve the U.S. in military conflicts of questionable interest with fewer worries about organized anti-war movements.
The conclusions of my research revealed that my hypothesis was wrong in that the creation of the AVF did not mean the U.S. presidency enjoyed a higher degree of support during conflicts. With the exception of the Gulf War, presidential approval when using the AVF was less than 50% in every conflict by the time military operations ended. The majority of conflicts disclosed that public approval and disapproval was based on casualties, regardless if service members were draftees or volunteers, as well as financial costs. For Korea and Vietnam, high casualties and financial costs resulted in approval levels dropping quickly while Afghanistan and Iraq took longer because casualties and spending did not escalate as quickly. As a result, I discovered that public approval and disapproval levels influenced political change. In the case of Korea, Vietnam, Afghanistan, and Iraq, it forewarned changes in political leadership while conflicts such as Somalia, Bosnia, and Kosovo were kept short and inexpensive to prevent political opposition from organizing against the presidency.<br>Master of Arts<br>This thesis explores presidential use of military power from 1949 through 2016, examining the impact of the All-Volunteer Force (AVF). The research looks at whether the AVF is associated with U.S. presidents having more public support when using military power in various parts of the world. Prior to the AVF, conscription helped meet the personnel needs of the U.S. military; however, this system became problematic when it was used to fight conflicts that became unpopular with the American public. Not only were the loyalty and performance of the conscripts often questionable, the public also frequently placed pressure on presidents to curb U.S. military operations overseas. This thesis examines the emergence of the AVF, how presidents have deployed it, and the differences in American public support, casualties, and financial costs between the use of the conscript force and the AVF under U.S. presidents in major military conflicts from 1949 through 2016. The findings revealed very little difference in presidential use of military power whether employing the conscript force or the AVF. An examination of the nation’s major conflicts since 1949 suggests that public support was based on U.S. lives lost and monies spent, with higher levels of these categories associated with lower presidential approval and higher disapproval ratings. In conclusion, although the AVF was created to end the need for the draft to support national defense, the American public remained concerned about how U.S. presidents used the military overseas especially when engaged in distant open-ended conflicts.
15
Lamb, Jason B. "Air Force intelligence officer regional specialization : force multiplier or divider? /." Maxwell AFB, Ala. : School of Advanced Air and Space Studies, 2008. https://www.afresearch.org/skins/rims/display.aspx?moduleid=be0e99f3-fc56-4ccb-8dfe-670c0822a153&mode=user&action=downloadpaper&objectid=4cb2fb80-0787-44f9-a71b-eae9b363c57c&rs=PublishedSearch.
Testo completo
16
Buss, John, Rico Magbanua, Chrisman Thompson, Wei Quan Toh, Min Yan Tan, John Goff, Andrew Moss, et al. "Distributed surface force." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42716.
Testo completoAbstract (sommario):
Approved for public release; distribution is unlimited<br>Large naval surface combatants are potentially held at risk by adversarial anti-access aerial denial (A2AD) weapon systems. To mitigate that risk we propose a distributed surface force concept, which relies on a cost-effective small surface combatant (SSC) capable of augmenting current forces in the 2025–2030 timeframe. We show that dispensing offensive and defensive power onto numerous smaller platforms has several advantages, including a more resilient force structure, greater number of ships, and fiscal cost savings. After employing the systems engineering process tailored to the problem to understand requirements and alternatives, a single mission SSC adapted to anti-surface warfare (ASUW) emerged as the solution. The SSC is conceptually employed in an armada composed of existing naval forces, which provide a protective shield against a multi-threat enemy force. The Armada is nominally composed of Arleigh Burke-class destroyers, Littoral Combat Ships and SSCs. The SSC’As capabilities include eight anti-ship cruise missiles with a range of 90 nautical miles, speed greater than 25 knots, and organic detection and classification range of at least 60 nautical miles.
17
PeÌrez, JoseÌ CristoÌbal Valera. "Electric force microscopy." Thesis, University of Exeter, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400970.
Testo completo
18
McKendry, Rachel Anne. "Chemical force microscopy." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624272.
Testo completo
19
Compère, Geoffrey, Samuel E. Gralla, and Alexandru Lupsasca. "Force-free foliations." AMER PHYSICAL SOC, 2016. http://hdl.handle.net/10150/622485.
Testo completoAbstract (sommario):
Electromagnetic field configurations with vanishing Lorentz force density are known as force-free and appear in terrestrial, space, and astrophysical plasmas. We explore a general method for finding such configurations based on formulating equations for the field lines rather than the field itself. The basic object becomes a foliation of spacetime or, in the stationary axisymmetric case, of the half-plane. We use this approach to find some new stationary and axisymmetric solutions, one of which could represent a rotating plasma vortex near a magnetic null point.
20
Martinho, Hélia Marisa Fonseca. "European gendarmerie force." Master's thesis, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa, 2012. http://hdl.handle.net/10362/8071.
Testo completoAbstract (sommario):
Relatório de Estágio apresentado para cumprimento dos requisitos necessários à
obtenção do grau de Mestre em Ciência Política e Relações Internacionais, na
variante de Estudos Europeus<br>A EGF/Eurogendfor – European Gendarmerie Force – foi criada com o propósito
de auxiliar as forças militares e civis no terreno. Facto é que os seus dias podem estar
contados, caso não se redefinam novas estratégias de actuação e novas valências para
os elementos que integram a força.
No seio da União Europeia [UE] esta organização tem, até à data, sido bem vista
pelos países que a representam. No entanto, dadas as suas especificidades e regras de
adesão à mesma, os restantes países podem sentir‐se postos à margem quando a EGF
representa a UE em missões internacionais.
Este problema só será ultrapassado se nos estatutos da EGF a força for alargada
a qualquer país europeu, independentemente das características das suas forças
policiais.
Quanto ao futuro, são vários os caminhos apontados. As suas possíveis missões
podem abarcar a protecção de sites europeus e/ou localizações diplomáticas da UE no
mundo; proceder a uma reforma no sector da segurança; estar presente em eleições
ou acordos eleitorais passíveis de criar conflito; prestar apoio na investigação de
crimes de guerra, contrabando de bens e pessoas; cooperar em tarefas internas dos
Estados‐membros; entre outras [Michiel de Weger, 2009].
Pela sua importância, não só a nível europeu como mesmo no contexto
internacional, este tema constitui o núcleo central do estágio realizado no Instituto de
Estudos Superiores Militares [IESM].
21
Ulrich, Elaine. "Hydrodynamic Force Microscopy." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195004.
Testo completoAbstract (sommario):
Microfluidic networks and microporous materials have long been of interest in areas such as hydrology, petroleum engineering, chemical and electrochemical engineering, medicine and biochemical engineering. With the emergence of new processes in gas separation, cell sorting, ultrafiltration, and advanced materials synthesis, the importance of building a better qualitative and quantitative understanding of these key technologies has become apparent. However, microfluidic measurement and theory is still relatively underdeveloped, presenting a significant obstacle to the systematic design of microfluidic devices and materials. Theoretical challenges arise from the breakdown of classical viscous flow models as the flow dimensions approach the mean free path of individual molecules. Experimental challenges arise from the lack of flow profilometry techniques at sub-micron length scales. Here we present an extension of scanning probe microscopy techniques, which we have termed Hydrodynamic Force Microscopy (HFM). HFM exploits fluid drag to profile microflows and to map the permeability of microporous materials. In this technique, an atomic force microscope (AFM) cantilever is scanned close to a microporous sample surface. The hydrodynamic interactions arising from a pressure-driven flow through the sample are then detected by mapping the deflection of an AFM cantilever. For gas flows at atmospheric pressure, HFM has been shown to achieve a velocity sensitivity of 1 cm/s with a spatial resolution of ~ 10 nm. This compares very favorably to established techniques such as hot-wire and laser Doppler anemometry, whose spatial resolutions typically exceed 1 μm and which may rely on the use of tracer particles or flow markers. We demonstrate that HFM can successfully profile Poiseuille flows inside pores as small as 100 nm and can distinguish Poiseuille flow from uniform flow for short entry lengths. HFM detection of fluid jets escaping from porous samples can also reveal a "permeability map" of a sample’s pore structure, allowing us to distinguish between clear and blocked pores, even in cases where the subsurface fouling is undetectable by conventional AFM. The experimental data is discussed in context with theoretical aspects of HFM microflow measurement and practical limits of this technique. Finally, we conclude with variations of standard HFM techniques that show some promise for investigation of smaller nanometer-scale flows of gases and liquids.
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Colacicchi, Federico <1988>. "GLOBAL SALES FORCE." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/10583.
Testo completoAbstract (sommario):
L’elaborato indaga il ruolo delle reti di vendita internazionali nel processo di internazionalizzazione mercantile delle piccole e medie imprese italiane. Il lavoro si suddivide in tre parti. La prima parte è dedicata all’analisi del concetto e delle forme di internazionalizzazione d’impresa. Si identificano le principali modalità di accesso ai mercati attraverso la ricostruzione dei principali modelli teorici e tecnico-organizzativi.
La seconda parte del testo si concentra sull’analisi del contratto internazionale di agenzia commerciale quale modalità di accesso al mercato attraverso esportazioni dirette. Viene definita la natura dell’agente di commercio nei principali mercati, esplorate le dinamiche legislative che regolano il rapporto di agenzia e discussi i principali modelli di management delle reti di vendita internazionali.
L’ultima parte della tesi, infine, si concentra su alcune recenti tendenze in fatto di commercio internazionale toccando temi come l’e-commerce, la manifattura additiva, la valorizzazione dei big data e il ruolo dei social media nella vendita estera, sottolineando il carattere sfidante che questi elementi rappresentano per le reti di vendita internazionali
23
Yim, Jung Woo. "Feasibility of implementing an all-volunteer force for the ROK armed forces." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion.exe/07Mar%5FYim.pdf.
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Siefert, Andrew William. "Mitral valve force balance: a quantitative assessment of annular and subvalvular forces." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53434.
Testo completoAbstract (sommario):
In vitro and in vivo models were proposed to evaluate the effects of ischemic mitral regurgitation and surgical repair on the function and mechanics of the heart’s mitral valve. In specific aim 1, a novel transducer was developed to measure the radially directed forces that may act on devices implanted to the mitral annulus. In an ovine model, radial forces were found to statistically increase with left ventricular pressure and were reduced in the setting of ischemic mitral regurgitation. In specific aim 2, the suture forces required to constrain true-sized and undersized annuloplasty rings to the mitral annulus of ovine animals was evaluated. Suture forces were observed to be larger on the anterior aspect of the rings and were elevated with annular undersizing. In specific aim 3, an in vitro simulator’s ability to mimic healthy and ischemic mitral regurgitation ovine mitral valve function was evaluated. After understanding the accuracy of the model, the in vitro ischemic mitral regurgitation model was used to evaluate the progressive effects of annuloplasty on strut and intermediary chordal tethering. The generated data and knowledge will contribute to the development of more durable devices and techniques to assess the significant clinical burden known as ischemic mitral regurgitation.
25
Kong, Jiang-Ti 1975. "Measuring the electrostatic repulsion forces between glycosaminoglycans using the atomic force microscope." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85370.
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Jordan, Alexander D. W. (Alexander David Weigert). "Designing for forces : an early-stage design program for axial-force structures." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65738.
Testo completoAbstract (sommario):
Thesis (S.B. in Art and Design)--Massachusetts Institute of Technology, Dept. of Architecture, 2011.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 64).<br>Structures that carry most of their load through the axial forces of tension or compression are more materially efficient than standard structures. However, they are not as straightforward to design since the forces in the structure depend on shape. The traditional method of form finding for such axial force structures is to create physical hanging models. These models are slow to produce and difficult to measure. Few digital design aids exist for designing axial force structures, and those that do tend to be for optimization or analysis, not necessarily for early stage design. In addition, they tend to lack desired functionality for a design program, and also tend focus on creating forms without considering engineering functionality. Since form and forces are so intertwined in axial-force structures, consideration of both in the early stages of design is desirable and is not fully addressed by existing programs. This thesis presents a new early stage design program, ForceDesigner, which improves the functionality of earlier programs and facilitates design by both architects and engineers. It builds on earlier design programs that use the particle spring system for creating digital hanging models, implementing the system in Processing and Java. The result is a program with a number of novel functions that allows designers interested in both form and forces to more quickly and easily create an unlimited number of efficient structures.<br>by Alexander D. W. Jordan.<br>S.B.in Art and Design
27
Rönnblom, Kristoffer. "An entrepreneurial military force? : A Governmentality analysis of Swedish Armed Forces recruits." Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-402929.
Testo completoAbstract (sommario):
This thesis aims to analyse how well recruits of the Swedish Armed Forces (SAF) have embraced soldier ideals put forward by the SAF following a shift in means of recruiting, changing from a system of compulsive conscription to an All-volunteer force (AVF). This has been done using a Governmentality-analysis of an extensive survey conducted at Ärna Air Base in November of 2019. The concept of Governmentality has to do with the way states and other forms of authorities govern. Launched in the 1970s by French philosopher Michel Foucault, it is based on an understanding that states no longer governing mainly by force, but rather by appealing to its citizens’ free will governing through “the conduct of conduct”, through the creation of self-governing subjects. The recruits were asked to rank different reasons for enlisting, and to assess various ideal qualities of a soldier, as well as pictures used by the SAF with the intention to recruit soldiers. The results were widespread and showed a big dissonance both among the recruits internally but also between the SAF’s military identities promoted by the SAF and the recruits. In some instances, the recruits seem to embrace the SAF’s ideals and in others they seem to be hostile of them. A few reasons for this are suggested in the final chapter of the thesis for example the societal collective understanding of the SAF or the role of the instructing officers.
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Leaf, Timothy D. "Investigation of the vertical distribution of seismic forces in the static force and equivalent lateral force procedures for seismic design of multistory buildings /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1136093311&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Fakih, Mahmoud. "Modélisation numérique discrète de la croissance racinaire dans un sol : relation force-forme." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT323/document.
Testo completoAbstract (sommario):
Les racines des plantes jouent un rôle important dans la croissance et le développement des plantes, et il est bien connu que les interactions mécaniques entre une croissance racinaire et le sol environnant peuvent avoir un impact majeur sur la croissance des racines et par conséquent sur la production de biomasse végétale. Ces interactions mécaniques sont l'un des nombreux facteurs qui peuvent expliquent la variabilité de l'architecture des racines, y compris les facteurs génétiques, environnementaux et l'instabilité du développement. Mais ce facteur a souvent été sous-estimé. Nous supposons que la structure hétérogène du sol à l'échelle des grains, démontrée par la large répartition des forces, peut influencer d'une manière significative sur les trajectoires de croissance des racines. Ce travail de thèse vise à déterminer comment les grains dans les sols granulaires se réorganisent sous l'action de la croissance des racines, et en retour, comment les forces résultantes agissant sur les apex des racines modifient leur développement, y compris la cinématique de leurs trajectoires. Nous avons développé un modèle numérique 2D de la croissance des racines dans un milieu granulaire en utilisant la méthode des éléments discrets (DEM). Le modèle est capable de calculer les forces de contacts grain-grain et racine-grain dans un milieu granulaire. Le système racinaire est modélisé en utilisant des chaînes d'éléments de spheroline connectés. L'orientation de la croissance des racines, à chaque étape de croissance est déterminée par la dynamique de la racine entière sous l'action des forces élastiques internes et des forces de réaction exercées par les grains, ces sont les interactions mécaniques qui contrôlent la croissance numérique dans le modèle.Des études paramétriques ont été réalisées afin (i) d'estimer l'influence de la structure granulaire (distribution de grains de diamètre, la cohésion, la fraction volumique ...) et les propriétés mécaniques des racines (la rigidité à la flexion) sur le signal de force axiale agissant sur la pointe de la racine, et sur les trajectoires et (ii) de définir les lois physiques générales qui peuvent être utilisées en outre pour analyser des données expérimentales. Les courbes de distribution des forces axiales calculées normalisées par leurs moyens au cours d'une période donnée de la croissance, sont caractérisées par une loi de puissance décroissante pour les forces en dessous de la force moyenne, et une décroissance exponentielle pour les forces ci-dessus de la force moyenne, reflétant ainsi la large répartition des forces à l'intérieur d'un matériau granulaire. Une analyse de l'écart-type des déformations locales des trajectoires des racines, résulte deux régimes en fonction la rigidité de la racine. Une première lorsque le sol contrôle les déformations des racines, et une deuxième lorsque la racine est trop rigide, et se déplace plus les grains environnants durant la croissance<br>Plant roots play an important role in the growth and development of plants, and it is well known that the mechanical interactions between a growing root and the surrounding soil can have a major impact on root growth and consequently on plant biomass production. These mechanical interactions are one of numerous factors that explain the variability of root architecture, including genetics, environment and developmental instability. But this factor has often been under-estimated. I hypothesize that the heterogeneous structure of soil at the particle scale, demonstrated by the broad distribution of forces, can significantly influence root growth trajectories. This thesis aims at determining how grains in granular soils are reorganized under the action of growing roots, and in return how the resulting forces acting on root tips modify their development, including the kinematics of their trajectories, in order to develop a general biophysical law of root-soil mechanical interactions. I developed a 2D numerical model of root growth in a granular medium using a Discrete Element Model (DEM). The model is able to compute grain-grain and root-grain contact forces within a granular medium. The root system is modelled using chains of connected spheroline elements. The orientation of root growth at every growth step is determined by the dynamics of the whole root under the action of its internal elastic forces and reaction forces exerted by the grains, which are the mechanical interactions that control numerical growth in the model.Parametric studies were carried out in order to (i) estimate the influence of granular structure (grain diameter distribution, cohesion, volume fraction) and root mechanical properties (root bending stiffness) on the axial force signal acting on the root tip, and on the root trajectories and (ii) define general physical laws that can be used further to analyze experimental data. The distribution curves of computed root tip-grain forces normalized by the mean force during a given period of growth were characterized by a decreasing power law for forces below the mean force, and an exponential fall-off for forces above the mean force, thus reflecting the broad distribution of forces inside the granular material. An analysis of the standard deviation of the local deformations of root trajectories resulted in two different regimes with regard root stiffness. In the first regime, soil controlled the root deformation and in the second, the root trajectory was straighter and displaced more significantly the surrounding grains during growth
30
Winsor, Fraser N. "Methods for removing inertial force from measured wave impact force signals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ55546.pdf.
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Murphy, Lee. "The Japanese self defence force : a force in transition 1990-2001 /." Title page, abstract and contents only, 2001. http://web4.library.adelaide.edu.au/theses/09AR/09arm9783.pdf.
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Razavi, Seyed Mostafa. "CROSS-PLATFORM FORCE FIELD DEVELOPMENT BASED ON FORCE-SMOOTHED POTENTIAL MODELS." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1590770530909963.
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West, Jerry. "Orthoplanar Spring Based Compliant Force/Torque Sensor for Robot Force Control." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6637.
Testo completoAbstract (sommario):
A compliant force/torque sensor for robot force control has been developed. This thesis presents methods of designing, testing, and implementing the sensor on a robotic system. The sensor uses an orthoplanar spring equipped with Hall-effect sensors to measure one component of force and two moment components. Its unique design allows for simple and cost effective manufacturing, high reliability, and compactness. The device may be used in applications where a robot must control contact forces with its environment, such as in surface cleaning tasks, manipulating doors, and removing threaded fasteners. The compliant design of the sensor improves force control performance and reduces impact forces.
Sensor design considerations are discussed, followed by a discussion of the proposed design concept. Theoretical compliance and stress analysis of the orthoplanar spring is presented that allows for rapid design calculations; these calculations are validated via finite element analysis. A mechanical design method is given which uses the results of the compliance and stress analysis. Transducer design is then addressed by developing a model of the sensor. The design methods are used to design a prototype sensor which is tested to determine its instrument uncertainty. Finally, the sensor is implemented on a robotic platform to test its performance in force control.
34
Lai, Chun-Chih. "Bovine serum albumin adhesion force measurements using an atomic force microscopy." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16418/1/Chun-Chih_Lai_Thesis.pdf.
Testo completoAbstract (sommario):
In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.
35
Lai, Chun-Chih. "Bovine serum albumin adhesion force measurements using an atomic force microscopy." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16418/.
Testo completoAbstract (sommario):
In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.
36
Vithayaveroj, Viriya. "Atomic force microscopy for sorption studies." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-09282004-121825/unrestricted/vithayaveroj%5Fviriya%5F200412%5Fphd.pdf.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2005.<br>Dr. Rina Tannenbaum, Committee Member ; Dr. Michael Sacks, Committee Member ; Dr. Sotira Yiacoumi, Committee Chair ; Dr. Costas Tsouris, Committee Co-Chair ; Dr. Ching-Hua Huang, Committee Member. Vita. Includes bibliographical references.
37
Voïtchovsky, Kislon. "Atomic force microscopy and force spectroscopy of biomembranes and applications to nanotechnology." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436928.
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Blake, Anthony William. "The force resistance of proteins revealed by single molecule atomic force microscopy." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417900.
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Antognozzi, Massimo. "Investigation of the shear force contrast mechanism in transverse dynamic force microscopy." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340356.
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40
Peters, Donald Blandford. "Determination of force coefficients for racing yacht sails using actual force measurements." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/12838.
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41
Hymon, Drema Ann. "Use of Force Citizen Complaints, Use of Force Violations, and Early Intervention." ScholarWorks, 2020. https://scholarworks.waldenu.edu/dissertations/7875.
Testo completoAbstract (sommario):
Abstract
Mounting public protests, increasing expensive payouts, and shootings of unarmed victims by police is a call to reexamine options to problem solving, service recovery, and preventing police misconduct as it pertains to the use of force. The purpose of this quantitative study was to examine the correlation between early intervention system data
(a) use of force, citizens' complaints (race and gender), and use of force violations (race, gender, and years of service for officers). The disruptive theoretical framework provided an innovative lens to examine police misconduct of a large midwestern large law enforcement agency. This secondary data study did not find significant relationships between stated variables using chi-square analyses. Although consistent with other studies, males were found likely victims of excessive use of force (X2 = 114.093, p =.000) using multiple regression. By expanding the characteristics of basic variables based on a (use of force) continuum model, the data can be treated as a disruptor with potential to reach maintenance or high productivity and sustainability. The fields of healthcare and education have made strides using this model, and this model may also add to the existing knowledge to create greater transparency, service recovery, and policy modification needed to reduce the use of force police misconduct. As society changes with varying political mandates, public opinions and technological communications, it is apparent that law enforcement must also continually improve efforts to enhance accountability and transparency relating to the use of force
42
Bermingham, Charlotte R. "Measurement of pico/femto-Newton scale forces using the lateral molecular force microscope." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715803.
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Muse, Robert C. "Advising foreign forces force structure implications of the indirect approach to irregular warfare /." Quantico, VA : Marine Corps Command and Staff College, 2008. http://handle.dtic.mil/100.2/ADA491120.
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DeMarco, J. William. "First in! expeditionary airbase seizure and operations power projection through mobility warriors /." CLICK HERE TO VIEW:, 2004. https://research.maxwell.af.mil/papers/ay2004/ari/DeMarco.pdf.
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45
Hoffman, Benjamin R. "Six-Component Load Cell Design for Use in Force Measurement Platforms." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1383950379.
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46
Schönenberger, Christian. "Understanding magnetic force microscopy /." Zürich : [ETH], 1990. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=9151.
Testo completoAbstract (sommario):
Diss. ETH no 9151, 1990.<br>A dissertation submitted to the Swiss Federal Institute of Technology Zurich for the degree of Natural Sciences, accepted for publication in "Zeitschrift für Physik B" Bibliogr.: p. 40-43.
47
Isaksson, Robert. "Drilling with force feedback." Thesis, Linköping University, Automatic Control, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-20897.
Testo completoAbstract (sommario):
<p>Industrial robots have been used for a long time in the industry. Despite this thedevelopment of advanced force control system using industrial robots is relativelylimited. Using force controlled robot systems expands the possibility of what canbe done with industrial robots.Previously a force feedback system for a standard industrial robot from ABBhas been developed. The system is developed towards the aircraft industry, where amounted drill machine on the robot has to fulfill the requirements in robot drillingin aircraft structures. This thesis presents experimental results and improvementsof this industrial robot system. Mechanical modifications and tests of a new endeffector are analyzed.</p>
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Stacklies, Wolfram. "Force Distribution in Macromolecules." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-39367.
Testo completoAbstract (sommario):
All living organisms utilize thousands of molecular building blocks to perform mechanical tasks. These building blocks are mostly proteins, and their mechanical properties define the way they can be utilized by the cell. The spectrum ranges from rope like structures that give hold and stability to our bodies to microscopic engines helping us to perform or sense mechanical work.
An increasing number of biological processes are revealed to be driven by force and well-directed distribution of strain is the very base of many of these mechanisms. We need to be able to observe the distribution of strain within bio-molecules if we want to gain detailed insight into the function of these highly complex nano-machines. Only by theoretical understanding and prediction of mechanical processes on the molecular level will we be able to rationally tailor proteins to mimic specific biological functions.
This thesis aims at understanding the molecular mechanics of a wide range of biological molecules, such as the muscle protein titin or silk fibers.
We introduce Force Distribution Analysis (FDA), a new approach to directly study the forces driving molecular processes, instead of indirectly observing them by means of coordinate changes.
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Liu, Yanzhang. "Magnetic dissipation force microscopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0016/NQ44497.pdf.
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Liu, Yanzhang 1963. "Magnetic dissipation force microscopy." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35002.
Testo completoAbstract (sommario):
This thesis concentrates on Magnetic Dissipation Force Microscopy---instrumentation, experiments and theory of the origin of magnetic dissipation.<br>A home-built vacuum magnetic force microscope (MFM) was debugged. The electronic noise in the system was reduced to below the thermal cantilever noise and the microscope now operates at its theoretical maximum (thermally limited) sensitivity. Then, a new technique, magnetic dissipation imaging, was developed. It allows the imaging of variations of 10-17 W in dissipation with sub-100 nm resolution. A normal MFM image and a magnetic dissipation image can be acquired simultaneously on the same area of a sample.<br>A theory was developed which correlates the dissipation with micromagnetic structures in domain walls. We consider the energy dissipation through coherent generation of phonons via magnetostriction induced by domain wall width oscillations. A quantitative agreement of theory with experiments for a 110 nm thick Co/Ni multi-layer and a 4 nm thick Co film samples was obtained. This theory predicts two new phenomena: a minimum drive force needed to cause wall width oscillations and wall width resonances.<br>With the above mentioned microscope, magnetic domain structure, micromagnetic domain wall structure and the associated dissipation have been studied on several samples, including a 30 nm thick Ni80Fe20 patterned into 20 mum squares and a CoPtCr recording medium. The dissipation results show strong correlations with magnetic domain structure. In the Ni80 Fe20 sample, the dissipation signal shows pronounced maxima correlated with the domain wall positions. We suggest magnetoelastic losses and eddy current losses due to wall jumps are the origins of the dissipation. With an in-situ magnetizing stage, we also studied magnetization reversal processes and dissipation hysteresis in the Ni80Fe20 sample. Besides the nucleation and growth of reverse domains, the formation of a 360º wall was observed. The CoPtCr sample shows different dissipation properties with both larger and smaller than average dissipation value observed in the transition regions.