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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"point force"”.
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The elastic stress field produced by a point force in a cubic crystal
… principle for the dis-placements generated by a point force at the origin in an infinite elastic solid. Eshe1by in 1955 gave an approximate solution of the dilatation for the triple force at the origin wi th no moment. Eshe1by and Leibried gave expressions which converge only when [equation] The …
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Respiratory behaviour and quality attributes of fresh apple slices in modified atmosphere systems
… only a logarithmic relationship. The crossover point between the linear and logarithmic portions of the biphasic O₂ consumption curve was recognized as the transition O₂ level. Depending on the temperature, transition O₂ levels for apple slices ranged from 0.81 to 4.5% O₂ for Granny Smith and …
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Poroelastic Center of Dilation Revisited
… used to refer to a singular solution such as the point force, the force dipole, the centers of rotation and dilation, etc. These fundamentals solutions constitute the building blocks for various problems of practical importance and are, therefore, relatively well understood. However, a comparison …
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Active control of flexural power flow in elastic thin beams
… in infinite, semi-infinite and finite beams by point force inputs has been analytically and experimentally studied. The systems were analyzed by assuming wave solution and then applying various terminating boundary conditions. Optimal control solutions were then obtained using a quadratic Wiener …
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Wave Propagation Problems in Certain Elastic Anisotropic Half Spaces
… conditions subjected to a suddenly applied line force on the surface or in the interior of a half space. The second type treats the three-dimensional problem of a point force suddenly applied on the surface of a transversely isotropic half space. This solution is formed, in general, by a …
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Advanced sensing techniques for active structural acoustic control
… physically with a shaker and modelled by a point force input. Structural acoustic control was achieved with piezoelectric actuators bonded to the surface of the test structure. The primary focus of this work was devoted to studying alternative sensing techniques in feed forward control …
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Active control of sound radiation from fluid loaded plates
… by a flexural wave in an infinite plate, or by a point force on a finite plate at subsonic frequencies. The wave scattering is caused by discontinuities on the plate or by the boundary conditions. A feed-forward control approach is applied by implementing either point/line forces or piezoelectric …
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Active control of a coupled plate-cylinder system
… number of active-passive mounts. A harmonic point-force disturbance is applied to the plate. Various active control approaches are applied to minimize the acoustic pressure radiated by the coupled system. The Active Structural Acoustic Control (ASAC) approaches include the control of the …
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Active control of broadband acoustic radiation from structures
… zero mean white noise and was input with a point force shaker. In the control of harmonically excited systems, satisfactory attenuation is possible with a single-input single-output (SISO) controller. In contrast, for Systems excited with broadband disturbances, a MIMO controller is …
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A Comprehensive Methodology for Assessing Biomechanical Risks Associated with Hand Tool Use: Applied to Laparoscopic Surgical Instruments
… forearm muscles used in wrist stabilization. Point-force sensors were used to evaluate grip and actuation forces that occurred while using various laparoscopic medical devices. The force plate gathered information on subject center of pressure location as well as moment and friction forces …
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Application of distributed measurements for finite element model verification
… measurements for a simple structure excited by a point force (from a shaker) and by a distributed force (from a single or pair of piezoceramic actuators). The analytical results are obtained from the forced response analysis of a finite element model. A known piezoelectric actuator model that …
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Optimization of transducers for active structural acoustic control of complex structures using numerical techniques
… for the optimization of control actuator forces and locations to minimize the total radiated sound power from complex structures has been developed. This optimization procedure interfaces finite and boundary element models with non-linear optimization techniques. The optimization procedure …
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Active control of acoustic radiation due to discontinuities on thin beams
… disturbed by a harmonic, subsonic input from a point force shaker. Control actuator( s) (in the form of shakers and piezoelectric actuators) were attached to the beam near the discontinuity. Error microphone(s) were positioned in the acoustic field which supplied an error signal to the digital …
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Effects of Wire Material, Deflection, and Interbracket Distance on Burstone Bracket Geometry Force Systems
… of the six-geometries: the moment dissociation point (force system with no moment on the lesser angled bracket), which may or may not occur at the classically defined geometry IV. Materials and Methods. A six-degree of freedom load cell was used to measure the force systems in different …
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Simultaneous active passive/control of extensional and flexural power flows in infinite thin beams
… of high damping placed at some distance from a point force excitation (passive approach). The passive control of vibrations results in a reduction of both extensional and flexural power flows downstream of the passive material discontinuity. The simultaneous active control of extensional and …
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Structure Borne Noise Analysis Using Helmholtz Equation Least Squares Based Forced Vibro Acoustic Components
… these critical vibration components from the point of view of direct contribution to sound radiation and hence cannot guarantee the best cost-effective noise reduction.</p> <p>The technology developed here provides a strategy towards identifying the critical vibration components and …
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Assessment of Antistripping Agents on Adhesion of Damaged Asphalt by Neural Network
… is developed to quantify nano-level adhesion force of moisture damaged asphalt binder using Atomic Force Microscopy (AFM) test data. AFM data contains five point force-distance values determined for some specific asphalt chemical functional groups. Asphalt binder samples contain different …
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Simultaneous active control of flexural and extension power flow in thin beams
… both finite and semi-infinite beams subjected to point force excitation at the free end. These actuator and sensing techniques when combined with an multiple input/output adaptive controller can simultaneously control flexural and extensional power flow in regions of a beam system over a band of …
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Control of Radiated Noise from Fluid-Loaded Stiffened Structures
… when a stiffened structure is excited by a force. Hence, this work aims to understand the propagation of BF waves and their contribution to the radiated sound power by utilising non-negative intensity (NNI) technique. Additionally, a passive control technique based on the acoustic black …
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Power efficiency analysis for an Active structure
… actuator. Power efficiency is analyzed for point force actuation and distributed moment actuation. Numerical simulations demonstrate that maximizing the power efficiency requires that the magnitude and phase of the structural modal velocity vector be matched to that of the eigenvector that …
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