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DRISSI, AMAR. "Formes, forces et figures de restructuration d'entreprise". Palaiseau, Ecole polytechnique, 1998. http://www.theses.fr/1998EPXX0057.
Pełny tekst źródłaThis dissertation deals with a specific type of corporate remodelling called restructuring. The main hypothesis goes as follows: a corporate restructuring goes through the close linking of mechanics and a mystique setting up a three-element configuration within which myths, rituals and tribes are mutually supportive. In other words, mobilizing change forces happens through a mobilization of meaning buttressed by mediations and mediators who translate it and embody it within what is fundamentally the linking of a (symbolic) legitimacy and an (objective and operational) factuality at the juncture of forces and meaning. The demonstration will unfold through three moments. -first, a review of the existing literature will evidence a certain number of prevailing normative archetypes that refer to the existence of a utopian problemizing focused on radical renewal patterns instead of fixing schemes and this within a specific context where managerial scientism meets a desire of reenchantment. -second, a case study: the restructuring of the jerada coal mine (morocco) by the author between 1992 and 1994. Through a " reflective practitioner" posture and a "reflection in action" stance as inspired by donald schoen, the author reconstructs the composite genealogy of a specific case of restructuring as rooted in symbolic and material terrains, economic and institutional resources, identity-powered and profane levers. At the end of this investigation and the evidencing of a certain number of memories and reactivations related to moroccan history, the author sets to call his method of corporate realignment as a "neo-maraboutic" model of restructuring resulting from interactions and grafts between heterogeneous rationalities: the classical tradition of moroccan maraboutic power, the problematic of coal mining, modernistic and managerial acculturation, islam as background and foreground; -third, a certain number of oblique lights on the basis of two case studies (one initiated by the author and still in progress since 1996: lesieur, the other one dealing with the ratp experience under blanc's management from 1989 to 1992) will allow for a second reading of the jerada experience as well as some theoretical revisions specifically with regard to the so-called political model of corporate transformation. Such cross-confrontations reinforce the main hypothesis of successful corpora
Perry, Katherine. "Combining forces". Connect to resource, 2008. http://hdl.handle.net/1811/32124.
Pełny tekst źródłaBuswell, Philip A. "Keeping Special Forces special: regional proficiency in Special Forces". Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/10750.
Pełny tekst źródłaRegional proficiency is a critical capability in irregular warfare (IW). In preparation for increased engagement in irregular warfare, the Defense (DoD) and the Military Services made several significant improvements in developing regional proficiency. While the DoD is attempting to create a new capability in the majority of the Total Force, Special Forces was created to succeed in an IW environment. As a result of its design, Special Forces valued and developed regional proficiency long before this became topical in DoD. Oddly, the last decade of overseas contingency operations which spurred interest in regional proficiency in DoD overall has also threatened regional proficiency development in Special Forces. An analysis of Special Forces training and development reveals that the Special Forces primary means of developing regional proficiency is through deployment experience. While the Special Forces Groups are regionally aligned, several have consistently deployed outside of their Area of Responsibility (AOR) to support combat operations in Iraq and Afghanistan. A survey and a series of interviews were conducted to determine the state of regional proficiency interest in Special Forces. Through survey analysis, several trends were identified. With this information this thesis concludes with a suggested strategy to improve regional proficiency in Special Forces non-commissioned officers (NCOs).
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.
Pełny tekst źródłaThis 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
Göpfert, Alois. "Classical description of dynamical many-body systems with central forces, spin-orbit forces and spin-spin forces". Bordeaux 1, 1994. http://www.theses.fr/1994BOR10551.
Pełny tekst źródłaSweetman, Adam. "Forces at the nanoscale : interactions in atomic force microscopy and dielectrophoresis". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11213/.
Pełny tekst źródłade, Mesa Winell. "Downsizing the United States Air Force Security Forces: A Phenomenological Investigation". ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/351.
Pełny tekst źródłaГулий, Олександр Миколайович, Александр Николаевич Гулый, Oleksandr Mykolaiovych Hulyi i S. V. Tokarev. "Rotor dynamic forces". Thesis, Видавництво СумДУ, 2004. http://essuir.sumdu.edu.ua/handle/123456789/22937.
Pełny tekst źródłaCAILLAUD, SEBASTIEN. "Excitation forcee et controle actif pour la mesure des forces fluide-elastiques". Paris 6, 1999. http://www.theses.fr/1999PA066553.
Pełny tekst źródłaBartolo, Denis. "Forces et Fluctuations : Forces induites par l'agitation et reponse d'adhesifs moleculaires". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00003804.
Pełny tekst źródłaBartolo, Denis. "Forces et fluctuations : forces induites par l'agitation et réponse d'adhésifs moléculaires". Paris 6, 2003. https://pastel.archives-ouvertes.fr/tel-00003804.
Pełny tekst źródłaYim, 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.
Pełny tekst źródłaSiefert, 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.
Pełny tekst źródłaKong, 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.
Pełny tekst źródłaJordan, 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.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (p. 64).
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.
by Alexander D. W. Jordan.
S.B.in Art and Design
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.
Pełny tekst źródłaPh. D.
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.
Pełny tekst źródłaTajti, Norbert. "Enhancing Hungarian Special Forces through transformation--the shift to Special Operations Forces". Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun%5FTajti.pdf.
Pełny tekst źródłaThesis Advisor(s): Lee. Doowan ; Second Reader: Greenshields, Brian H. ; Third Reader: Porkolab, Imre. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Special Forces, Special Operations Forces, Hungary, organizational design, special operations, NATO. Includes bibliographical references (p. 103-108). Also available in print.
Büscher, Rauno. "Casimir forces and geometry". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976592533.
Pełny tekst źródłaDickey, Mary-Margaret. "WAVE FORCES ON BRIDGES". MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11072008-080046/.
Pełny tekst źródłaAsokan, Sreeja B. Superfine Richard. "Forces in cytoskeletal systems". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,65.
Pełny tekst źródłaTitle from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics and Astronomy. Chapel Hill 2006." Discipline: Physics and Astronomy; Department/School: Physics and Astronomy.
Foulkes, William Matthew Colwyn. "Interatomic forces in solids". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328669.
Pełny tekst źródłaWells, B. H. "Studies in intramolecular forces". Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355824.
Pełny tekst źródłaRead, Christopher S. "Allegiance: Egypt security forces". Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/38998.
Pełny tekst źródłaIn Egypt, opposition groups challenged the Mubarak Regime and toppled it. More than two years later, demonstrators against the military-backed government that deposed President Morsi were brutally put down and rule stayed with the junta. This thesis examines those events in Egypt and focuses on opposition tactics used and the response elicited from security force elements. It seeks to discover where, in 2011, security forces were not given or disobeyed the order to shoot protestors and, in 2013, ruthlessly followed that order. This thesis analyzes opposition tactics and questions whether those actions elicited loyalty shifts within security forces and how any such shifts impacted the ability to achieve political change. The thesis uses a synthesis of objectives developed by Anika Binnendijk, labeled the Five Strategic Objective framework, along with social movement theory as they apply it to challenger actions. To these the author adds foreign involvement and internal dynamics. Data is gathered through in-depth review of relevant documentation: published news, discussions, books, and reputable web sources. Analysis of the sources shows that in 2011, a broad based appeal generated sympathy within security forces that precluded obeying a shoot order and that such sympathy was not present in 2013
Brampton, Christopher. "Forces in biomolecular systems". Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429077.
Pełny tekst źródłaJensen, Søren Trøjgård. "Forces on underwater vehicles". Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/36529.
Pełny tekst źródłaWehbe, Imad Najib. "Les forces politiques palestiniennes". Montpellier 1, 1999. http://www.theses.fr/1999MON10006.
Pełny tekst źródłaNadtochiy, Y. O. "Moving forces of technology". Thesis, Сумський державний університет, 2012. http://essuir.sumdu.edu.ua/handle/123456789/28721.
Pełny tekst źródłaPazhianur, Rajesh R. "Hydrophobic Forces in Flotation". Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/28066.
Pełny tekst źródłaPh. D.
Hom, John S. "Natural forces: inquiring beauty". The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1328809006.
Pełny tekst źródłaMoine, Olivier. "Modélisation de forces optiques". Aix-Marseille 3, 2005. http://www.theses.fr/2005AIX30055.
Pełny tekst źródłaThis work deals with theoretical modeling of optical forces on micro-meter scale objects using exact electromagnetic calculations. In the first part, we derive and review the two approximate techniques commonly used to calculate optic in the two extreme size domains : the Rayleigh approximation for dealing with particles considerably smaller than the wavelength, [lambda] , of the trapping radiation, and the geometric optics approximation which applies to particles much larger than [lambda]. We then illustrate the limits of these approximate techniques via a comparison with the exact calculations that we have developed. In the second part, we consider optical traps containing multiple particles. For such studies we couple our exact calculation technique with exact solutions of the multi-scattering equations in order to evaluate the optically induced forces that appear between particles in multiparticle traps. Most of our applications to date concern homogeneous spherical trapped particles, and a the third part studies the extension to more general particles like coated spheres which can be used to model biological organites like cells. The last part concerns the applications of theoretical modeling to the rapidly developing field of optical tweezers for mico-meter scale manipulation
Ji, Shunxi. "Forces and Stability in Ternary Colloidal Systems: Evidence of Synergistic Effects". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47803.
Pełny tekst źródłaPh. D.
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.
Pełny tekst źródłaMuse, 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.
Pełny tekst źródłaMoussus, Michel. "Forces mécaniques au sein de l'endothélium". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY008/document.
Pełny tekst źródłaVascular dysfunction or injury induced by aging, smoking, inflammation, trauma, hyperlipidaemia are among a myriad of risk factors that contribute to the pathogenesis of many cardiovascular diseases. An important objective in vascular biology is to understand cellular processes that promote or protect against cardiovascular diseases. This pathogenesis is very closely associated with dysfunction of the inner face of the vessel wall. The inner face of the vessel wall is lined by a monolayer of endothelial cells forming the vascular endothelium. Reparation of the endothelium involves remodelling of focal adhesionns (FA) and adherent junctions (AJ). Modifications in the protein composition of these adhesive structures generate forces at the basis of endothelium remodelling and reparation. In the literature, cellular forces are studied on single cells, epithelial cell doublets or cell aggregates in growth but mechanical forces inside tissues remains to be characterized. In this thesis, we use traction force microscopy (TFM) on polyacrylamide substrates to study the mechanical equilibrium between intercellular junctions and cell/substrate adhesion. We analyse to which extent TFM can be used for studying monolayers and present a novel approach to extract contractile forces exerted by an endothelial tissue. Finally, we use this methodology to characterize forces transmitted to the substrate and the contractile forces of endothelial monolayers. This method provides an interesting tool to study the contribution of some proteins of the adherent junctions to force transmission within the endothelium
Loudy, MIchael E. "Sustainment support for Naval Construction Forces operating with Marine Air-Ground Task Forces". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA326654.
Pełny tekst źródłaThesis advisor(s): Paul J. Fields, K.R. Gue. "December 1996." Includes bibliographical references (p. 75-76). Also available online.
Draper, Stephen R. ""EOD, Up!" how explosive ordnance disposal forces can best support special operations forces". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FDraper.pdf.
Pełny tekst źródłaMansouri, Yassine. "La localisation des activités productives : les tensions entre forces centrifuges et forces centripètes". Phd thesis, Université du Sud Toulon Var, 2008. http://tel.archives-ouvertes.fr/tel-00326119.
Pełny tekst źródłaMansouri, Yassine Gilles Philippe Boismery Hervé. "La localisation des activités productives Les tentions entre forces centrifuges et forces centripètes /". [S.l.] : [s.n.], 2008. http://tel.archives-ouvertes.fr/tel-00326119/fr.
Pełny tekst źródłaZold, Zoltan. "Professional armed forces new trend in Europe : transformation of the Czech armed forces". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FZold.pdf.
Pełny tekst źródłaThesis advisor(s): Raymond Franck, Donald Abenheim. Includes bibliographical references (p. 85-88). Also available online.
Malave, Carmen. "Deep hole drilling - Cutting forces and balance of tools". Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-20696.
Pełny tekst źródłaBulgakov, Igor G. "The Ukrainian Armed Forces in peacekeeping : new perspectives on the professionalization of peacekeeping forces". Thesis, Monterey, California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/6089.
Pełny tekst źródłaRapid changes have characterized international relations since the end of the Cold War. Transitioning democracies have been the scene of often-violent change, enduring civil war, political and economic struggle, and ethnic strife. Transitioning nations increasingly need peacekeeping operations to maximize their chances for success. Historically however, peacekeeping operations created by the United Nations have been ad hoc "coalitions of the willing" and have not been conducive to establishing professional peacekeeping forces. This thesis proposes that the more professional the peacekeeping operation, the higher the chance of success for the peacekeeping mission. The need for change to professional peacekeeping is particularly true for the Ukrainian Armed Forces. The development of standing national forces designed and trained to act in crisis management and peacekeeping operations is critical for success. Using the Polish-Ukrainian Peacekeeping Battalion (UKRPOLBAT) as a model, a separate brigade within the Ukrainian Armed Forces should be established to specifically and only perform peacekeeping missions. Thus, this unit could be used as a springboard to begin the professionalization of peacekeeping not only in Ukraine, but also in Europe and the rest of the world.
Moore, Sean O'Neill. "QUANTIFYING THE BIOMECHANICAL FORCES BETWEEN PROTEINS INVOLVED IN ELASTIN SYNTHESIS USING ATOMIC FORCE MICROSCOPY". Cleveland State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=csu1546450170942598.
Pełny tekst źródłaRangarajan, Murali. "Polymer-induced forces at interfaces". [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015689.
Pełny tekst źródłaRobertsen, Tom A. "Transforming Norwegian Special Operation Forces". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FRobertsen.pdf.
Pełny tekst źródłaHeintz, Sofia. "Muscular forces from static optimization". Licentiate thesis, KTH, Mechanics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3943.
Pełny tekst źródłaAt every joint there is a redundant set of muscle activated during movement or loading of the system. Optimization techniques are needed to evaluate individual forces in every muscle. The objective in this thesis was to use static optimization techniques to calculate individual muscle forces in the human extremities.
A cost function based on a performance criterion of the involved muscular forces was set to be minimized together with constraints on the muscle forces, restraining negative and excessive values. Load-sharing, load capacity and optimal forces of a system can be evaluated, based on a description of the muscle architectural properties, such as moment arm, physiological cross-sectional area, and peak isometric force.
The upper and lower extremities were modelled in two separate studies. The upper extremity was modelled as a two link-segment with fixed configurations. Load-sharing properties in a simplified model were analyzed. In a more complex model of the elbow and shoulder joint system of muscular forces, the overall total loading capacity was evaluated.
A lower limb model was then used and optimal forces during gait were evaluated. Gait analysis was performed with simultaneous electromyography (EMG). Gait kinematics and kinetics were used in the static optimization to evaluate of optimal individual muscle forces. EMG recordings measure muscle activation. The raw EMG data was processed and a linear envelope of the signal was used to view the activation profile. A method described as the EMG-to-force method which scales and transforms subject specific EMG data is used to compare the evaluated optimal forces.
Reasonably good correlation between calculated muscle forces from static optimization and EMG profiles was shown. Also, the possibility to view load-sharing properties of a musculoskeletal system demonstrate a promising complement to traditional motion analysis techniques. However, validation of the accurate muscular forces are needed but not possible.
Future work is focused on adding more accurate settings in the muscle architectural properties such as moment arms and physiological cross-sectional areas. Further perspectives with this mathematic modelling technique include analyzing pathological movement, such as cerebral palsy and rheumatoid arthritis where muscular weakness, pain and joint deformities are common. In these, better understanding of muscular action and function are needed for better treatment.
Fredheim, Arne. "Current Forces on Net Structure". Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-559.
Pełny tekst źródłaThe trend in recent years has been that the amount of wild catch is stagnating. In this perspective the selectivity of fishing gear has become an important issue. The aim of the present work has been to develop a three-dimensional model for the flow in front and inside a net structure, such as a trawl, to be able to predict and calculate selectivity of net structures. A net consist of twines which connect in knots and make up a mesh. The diameter of a twine can be from 1 [mm] in net cages up to a few centimeters in the front part of a trawl. And similar the size of the mesh can be from 1 [cm] up to the order of a meter. Typical Reynolds number range, related to the diameter of a twine, is O(102−104).
An examination of numerical results for the drag force on plane net structure demonstrates a strong dependency of the drag force on a net structure with both the geometry, in terms of Solidity ratio, and the Reynolds number. And in particular a non-uniform relation between the drag force and the Solidity ratio. It is evident that for increasing Solidity ratios, flow interaction will become increasingly significant. The physical design of the knot part contributes largely to this flow interaction.
The net structure is divided into discrete elements. The twines are modeled as separate cylinders between knots and the knots are modeled as separate spheres. Typically the total number of twines in a trawl could be in the order of 106 and it is thus impractical to model every single twine. It is assumed that for a given Reynolds number, keeping the Solidity ratio constant, the total drag on the trawl will be independent on the actual diameter and mesh opening of the net.
First each of these different elements is modeled as a set of source distributions and single point sources. The influence from the net on the fluid flow is then calculated by representing the wake generated by each element as source distributions along the structural element. To determine the strength of these sources the principle of Lagally is applied. Then a set of equations is obtained, describing the relation between the fluid velocity and the source strength at every element. Based on this approach, a method is presented to calculate the drag force on net structures with high solidity. The method uses appropriate drag coefficients related to the geometry of the twines and the knots and account for the change in the inflow due to the presence of the net structure and at the same time changes the geometry of the net structure due to the load.
Secondly the interaction between the net elements, due to the physical generation of a wake flow behind each individual element of the net, has been studied using a time-averaged wake model. Modifications are applied to the far-field mean velocity deficit mode by Schlichting (1968). This to better describe the the near-field behavior and the added effect of the wake from many individual cylindrical elements. It is shown that the wake model by Blevins (1990) can be used. The method is verified against experiments, as means of calculating the drag on plane nets as a function of Reynolds number, Solidity ratio and angle of attack and gives reasonable good agreement. During the experiments some interesting three-dimensional effects regarding the flow around cylinders were discovered. Negative lift forces occurring on the downstream cylinder in a staggered arrangement is explained as interactions due to upstream generated vortices.
To create a three-dimensional method where the inflow on each of the cylinders is corrected due to the presence of all the other cylinders, these two models are added together. Further, a structural analysis of the net structure, using a FEM method, is included in the model. A more complete description of the problem is obtained by combining the change in the inflow due to the presence of the net structure, with a correction of the shape and geometry due to the drag load.
Results from numerical simulation of different kinds of net structures, show that the elasticity in the net structure has a significant influence on the resulting geometry and calculated results. Further, the numerical results for net cages have been compared to experimental results. Good agreement between the numerical results and the experimental result is seen. Also the resulting geometry from the experimental results was recreated satisfactory using the present method.
For three-dimensional cone shaped net structures, in contrast to net panels and net cages, the presented numerical results do not indicate a large influence on the drag force due to changes in geometry. The agreement between the numerical and experimental results for fluid velocity in front and inside of a three-dimensional net structure, compared to experimental results, was reasonably good. Quantitatively the results do not match exactly, but the characteristics of the flow are recreated. Further, based on the numerical results for the fluid velocity, pressure field in front of a cone is presented. The relative pressure gradient is shown to be minimal, and it is not likely than any fish will detect this change in pressure field neither by direct pressure sensing nor by any sound created from any shed vortices.
Ådnanes, Håkon. "Forces on a net panel". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15468.
Pełny tekst źródłaStoneking-Stewart, Jennifer L. "Inevitable forces deciphering the environment /". Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1181252102/.
Pełny tekst źródłaVass, John D. V. "Retention in the Canadian Forces". Fort Leavenworth, KS : US Army Command and General Staff College, 2007. http://handle.dtic.mil/100.2/ADA475574.
Pełny tekst źródłaTitle from title page of PDF document (viewed on: Apr 2, 2008). Includes bibliographical references p. 89-93.