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A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenTue, 16 Apr 2024 16:08:25 +0000I. Depolarized Light Scattering Studies of Rotational-Translational Coupling in Liquids Composed of Small Anisotropic Molecules. II. Investigation of the Coupling Between Reorientation and Longitudinal Modes in the Brillouin Spectra of Liquids Composed of Anisotropic Molecules
https://resolver.caltech.edu/CaltechETD:etd-09142006-110153
Authors: {'items': [{'id': "O'Steen-Byron-Lance", 'name': {'family': "O'Steen", 'given': 'Byron Lance'}, 'show_email': 'NO'}]}
Year: 1982
DOI: 10.7907/wda1-bj76
<p>Part I</p>
<p>In an attempt to better understand the molecular interactions governing the behaviour of the coupling parameter R measured in light scattering experiments, the depolarized (l<sub>VH</sub>) spectra for a series of liquids composed of small aromatic molecules, very similar in size and shape, have been measured. The molecules studied here were generally monosubstituted benzene and pyridine derivatives. All were found to exhibit the doublet structure indicative of dynamic coupling between molecular reorientation and shear modes, or more simply, rotational-translational coupling. The degree of this coupling is measured by a parameter R (0 ≤ R ≤ 1) which is often thought of as the fraction of the shear viscosity attributable to reorientational motion. From the depolarized spectra the coupling parameter R, collective reorientation frequency, and low frequency shear viscosity were determined.</p>
<p>The values of R were found to vary from 0.24 to 0.55 for the liquids studied here. This range is nearly as broad as that observed in all previous studies, which have included such diverse molecules as carbon disulfide, tri-phenyl phosphite, and the highly anisotropic liquid crystal MBBA. This suggests that size and shape considerations, or steric forces, are not the primary factor in determining the degree of rotational-translational coupling as measured by light scattering. If this is indeed the case then other non-steric interactions must be producing the observed variation in R. With this in mind, we have examined possible electrostatic interactions. A simple correlation with dipole moment was not found to exist. Instead it appears that the variation in R can only be understood by consideration of the detailed molecular charge distribution. This is determined to a large extent by resonance interactions with the aromatic ring which are generally reflected in the change of dipole moment from the aliphatic compound (CH<sub>3</sub>-R) to its aromatic analog (C<sub>6</sub>H<sub>5</sub>-R).</p>
<p>Based upon resonance structure arguments and our own experimental results, it is concluded that the anomolously large R values found for pyridine from the l<sub>HH</sub> depolarized spectrum might well be correct and the more orthodox l<sub>VH</sub> measurements in error. If this assertion is indeed correct, then the reliability of rotational-translational coupling measurements by l<sub>VH</sub> depolarized light scattering must be considered questionable for weakly scattering molecules such as pyridine.</p>
<p>Part II</p>
<p>The coupling of reorientational motion to longitudinal modes was investigated by studying the Brillouin spectra of aniline and p-anisaldehyde over a wide range of scattering angles. The primary goal of these studies was to attempt to confirm the microscopic theory of orientational relaxation in the polarized spectrum. Theoretically it has been shown that for symmetric tops the coupling between longitudinal modes and reorientation in the polarized spectrum is identical to that between shear modes and reorientation in the depolarized spectrum. Thus the Brillouin scattering studies performed here also provide an internal check on the consistency of the 2-variable molecular theory for depolarized scattering and the corresponding theory of orientational relaxation in the Brillouin spectrum. Aniline and p-anisaldehyde were chosen for this investigation since their depolarized spectra at the temperature of interest are well described by the simple 2-variable molecular theory coupling shear modes to orientation. The collective reorientation frequency for both liquids could easily be varied in the low gigahertz range by operating at temperatures near the freezing point. Thus the effects of orientational relaxation in the propagation of longitudinal waves (1 - 10 GHz) should be observable in an angular study of the Brillouin spectra. Moderate viscosites and large rotational-translational couplings also made these liquids attractive from an experimental standpoint since these quantities determine the relaxation strength.</p>
<p>Our results for attenuation and velocity of the longitudinal waves demonstrate that there is indeed relaxation in the shear viscosity as predicted by theory. However, shear relaxation in addition to that due to reorientational motion is indicated by the k-dependence of the attenuation results. This stands as an apparent contradiction to the depolarized results which suggest that only orientational relaxation should be important under these conditions. Since the different relaxation effects cannot be unambiguously separated here, a detailed confirmation of orientational relaxation theory could not be obtained.</p>https://thesis.library.caltech.edu/id/eprint/3535An Engineering Analysis of Polymer Film Adhesion to Rigid Substrates
https://resolver.caltech.edu/CaltechETD:etd-05152007-111322
Authors: {'items': [{'id': 'Heymans-Luc-J', 'name': {'family': 'Heymans', 'given': 'Luc J.'}, 'show_email': 'NO'}]}
Year: 1983
DOI: 10.7907/3GQW-YP87
<p>An important source of interface fracture contributing to adhesive failure in a bimaterial sandwich, consisting of a rigid substrate and a viscoelastic encapsulant material, arises from residual stresses. The encapsulant is often deposited on the substrate above its glass transition temperature region but used below this temperature range. In order to determine the magnitude of the residual stresses a viscoelastic stress analysis of a bimaterial sandwich is carried out, taking into account the time-dependent material properties of the polymeric layer and the environmental "loading" conditions. The theoretical analysis is paralleled by an experimental examination of the time-dependent out-of-plane deformation of thin, circular sandwiches.</p>
<p>Polyvinyl acetate was chosen as a model material exhibiting significant viscoelastic effects under room test conditions. Therefore the pertinent physical and mechanical properties of PYA<sub>c</sub> are determined; these include the thermal coefficient of expansion, the shear creep compliance and the relaxation modulus. In the experimental work BK-7 glass is taken as the "rigid" substrate. The measurements connected to the stress analysis are monitored with laser interferometry (Newton's rings). A comparison between theory and experiment completes the viscoelastic stress analysis.</p>
<p>In the second part of this study time dependent adhesive failure of rubbery materials is investigated. Polymeric materials are being used increasingly for a wide variety of applications. Some of these materials are applied as protective layers to isolate their substrates from a hostile environment. Others achieve remarkable structural bond strengths thereby displacing the traditional mechanical fasteners like bolts and rivets. If one wants to investigate the long time integrity of a layer assembly the time dependence of the material properties of the adhesives needs to be carefully analyzed. This time dependence is also reflected in the energy required to create new surfaces as interfacial debonding proceeds the adhesive fracture energy is one of the dominant parameters in time dependent adhesive failure. In our investigation it is characterized through peel testing.</p>
<p>With the knowledge of the pertinent material properties as well as of the adhesive fracture energy, we then proceed to formulate a criterion for continuing interfacial crack propagation. The analysis is carried out for elastic solids, with the effect of viscoelastic behavior incorporated later on. Debond tests provide a way to check how well the theoretical predictions correspond to experimental debond results.</p>https://thesis.library.caltech.edu/id/eprint/1821Robust Sentence Analysis and Habitability
https://resolver.caltech.edu/CaltechETD:etd-11032005-154728
Authors: {'items': [{'id': 'Trawick-David-James', 'name': {'family': 'Trawick', 'given': 'David James'}, 'show_email': 'NO'}]}
Year: 1983
DOI: 10.7907/re17-h091
<p>Systems for using subsets of English with computers have progressed much in the area of linguistic coverage of well-formed sentences for a specific task. Some methods have also been devised for the treatment of input that is almost well-formed. Nevertheless, it is still quite easy to stray over the bounds imposed by current natural language systems. Without proper diagnosis, this leads to interactive systems that are not habitable, i.e., systems that are not pleasant to use because they are not able to perform up to the user's expectations.</p>
<p>This thesis presents an overall system for the treatment of several areas normally outside the limit of natural language systems, and for the diagnosis of any input. The system, Robust Sentence Analysis, includes procedures for handling ambiguous input, resolving input with anaphors (e.g. pronouns), making several kinds of major and minor corrections to input, and the interaction of all of these areas. The system does not treat every aspect of these methods of human interaction, but does provide for the more prevalent forms as found in simulations of user interaction in several modes: face-to-face, terminal-to-terminal, and human-to-computer (using a previously implemented natural language system). Thus the system incorporates the most likely forms found in human performance. Diagnostics are designed to lead the user back into the boundaries of the system.</p>
<p>The Robust Sentence Analysis system is implemented as a part of the ASK System, <u>A</u> <u>S</u>imple <u>K</u>nowledgeable System.</p>https://thesis.library.caltech.edu/id/eprint/4393Mathematical Modeling of Atmospheric Aerosol Equilibria and Dynamics
https://resolver.caltech.edu/CaltechETD:etd-11092005-105529
Authors: {'items': [{'id': 'Bassett-Mark-Elliott', 'name': {'family': 'Bassett', 'given': 'Mark Elliott'}, 'show_email': 'NO'}]}
Year: 1984
DOI: 10.7907/9mvc-2t06
<p>Atmospheric aerosols consist of submicron-sized particles occurring at number concentrations of the order of 10<sup>5</sup> cm<sup>-3</sup> and mass concentrations of the order of 100 µg m<sup>-3</sup>. These aerosols, when occurring in urban areas, consist of aqueous solutions of sulfate, nitrate, ammonium, organic constituents, and certain metals. This thesis is a contribution toward our ability to describe mathematically the formation and growth of such atmospheric aerosols. Since a substantial fraction of the mass of urban aerosols consists of sulfate, nitrate, ammonium and water (Stelson and Seinfeld, 1981), the description of the dynamics of such an aerosol is an important place to initiate the development of aerosol models. The size and composition distribution of atmospheric aerosols are governed by a combination of thermodynamics and kinetics. A detailed treatment of the thermodynamics of the atmospheric sulfate/nitrate/ammonium/water system is presented. Based on this treatment, models are developed to predict the equilibrium quantity, composition, state, and size of the aerosol given gas phase properties. Aerosol kinetics are approached by solution of the General Dynamic Equation for the aerosol sized distribution using the sectional method of Gelbard and Seinfeld. In the most general kinetic model presented, the evolution of the size and composition of an atmospheric sulfate aerosol is predicted under power plant plume conditions. Users manuals for the computer codes comprising the models developed here are given in the Appendix.</p>https://thesis.library.caltech.edu/id/eprint/4470The Dialogue Designing Dialogue System
https://resolver.caltech.edu/CaltechETD:etd-01022007-104438
Authors: {'items': [{'id': 'Ho-Tai-Ping', 'name': {'family': 'Ho', 'given': 'Tai-Ping'}, 'show_email': 'NO'}]}
Year: 1984
DOI: 10.7907/5v76-gn68
<p>This thesis presents an interactive system, the Dialogue Designing Dialogue System, that integrates natural language programming of user dialogues with a natural language system, the ASK system. This interactive system satisfies the basic criteria of a general programming language.</p>
<p>The system presented in this thesis may be referred to as a "meta-dialogue" system. Using this meta-dialogue, the user implements domain specific dialogues which he and others can then use, providing highly succinct and efficient interfaces for interaction with the computer.</p>
<p>The system combines the use of a syntax-directed and a semantic-directed system, which gives the user flexibility in specifying additional capabilities, and thus in turn gives the system itself a much broader domain of application. Further, the system integrates natural language programming, dialogue directed user interface, underlying data base, and text handling capabilities, so that it does not require users to have programming background in order to establish an application system for themselves.</p>https://thesis.library.caltech.edu/id/eprint/2Superposition of the Effects of Time, Temperature, and Pressure in Polymetric Materials
https://resolver.caltech.edu/CaltechETD:etd-06152004-145433
Authors: {'items': [{'id': 'Moonan-William-Kevin', 'name': {'family': 'Moonan', 'given': 'William Kevin'}, 'show_email': 'NO'}]}
Year: 1984
DOI: 10.7907/e970-mg79
<p>Stress relaxation was studied in torsion under superposed hydrostatic pressure using a newly constructed device. Combination of these measurements with the determination of expansivities and compressibilities and with earlier measurements of stress relaxation in tension leads to verification of the description of the combined effects of temperature and pressure on shear relaxation by an extension of the classical free volume theory. The predictions of an extension of the Adam-Gibbs theory to the pressure domain are also compared with the data. This theory is not as successful in predicting superposition. The data are also examined in light of an adaptation of the Simha-Somcynsky equation of state to the free volume theory. Prediction of the effect of pressure by the theory requires a single adjustable parameter. It was possible to calculate the free volume parameters of several polymers without use of information from high pressure experiments.</p>https://thesis.library.caltech.edu/id/eprint/2601Time Dependent and Equilibrium Stress-Strain Behavior of Rubbers in Moderately Large Deformations
https://resolver.caltech.edu/CaltechETD:etd-02252004-105813
Authors: {'items': [{'id': 'Gurer-Cigdem', 'name': {'family': 'Gurer', 'given': 'Cigdem'}, 'show_email': 'NO'}]}
Year: 1984
DOI: 10.7907/e0xe-8w83
<p>In this work, time dependent and equilibrium stress-strain properties of elastomeric networks are investigated for moderately large deformation. A two network potential is proposed, which constitutively describes stress-strain behavior at elastic equilibrium. The potential is applied to time dependent deformations thorough a molecular model.</p>
https://thesis.library.caltech.edu/id/eprint/751Studies of Flow Modification and Polymer Conformation in Extensional Flows of Dilute Polymer Solutions
https://resolver.caltech.edu/CaltechETD:etd-03212008-080541
Authors: {'items': [{'id': 'Dunlap-Paul-N', 'name': {'family': 'Dunlap', 'given': 'Paul N.'}, 'show_email': 'NO'}]}
Year: 1986
DOI: 10.7907/2v8j-nf26
<p>This is a study of the coil-stretch transition of macromolecules in dilute solutions which are subjected to extensional flows and of the effects of the polymer molecules on the flow fields. The flow fields are produced in a four-roll mill, two-roll mills of several different gap width to roller radius ratios, and a cylindrical Couette device. These flows are laminar, and approximately two-dimensional linear flows covering the range of flow types with different amounts of extension and vorticity from pure extension to simple shear flow. The two-roll mills were constructed to extend the previously accessible range of flow types to those with only slightly more extension than vorticity, <i>i.e.</i>, much nearer to simple shear flow. The flows are characterized by using homodyne light scattering spectroscopy to directly measure velocity gradients fields. The degree of polymer extension is monitored using flow birefringence measurements.</p>
<p>Studies using 100 ppm polystyrene in viscous solvents show that the flow birefringence data for all the different strong flows (simple shear is a weak flow) correlate with the eigenvalue of the velocity gradient tensor. Extensional flow birefringence data for the same polymer in different solvents correlate with the Zimm relaxation time based on the intrinsic viscosity. When the polymers are sufficiently extended there is a distinct onset of measurable decreases in the velocity gradients. A necessary condition for this to occur is a very high level of domain overlap between the extended molecules. If we estimate this by the volume concentration of circumscribed spheres, φ<sub>eff</sub> (i.e., the sphere diameter equals the extended length of the polymer), the onset of an effect of polymer on the flow does not occur until φ<sub>eff</sub> ~ 4000-6000. Nevertheless, our measurements show that dilute polymer solutions do inhibit the development of large strain rates in regions of persistent extensional flow.</p>
<p>Studies using sodium polystyrenesulfonate in glycerol with various amounts of added sodium chloride show the range of coil-stretch behavior that can occur as a function of the equilibrium conformation of the polyelectrolyte. With high ionic strength solutions, the polyelectrolyte behavior is the same as that of nonionic polymers. As the ionic strength decreases and the equilibrium dimensions increase, the onset of the coil-stretch transition shifts to much lower shear rates. With no added salt, the expanded coil approaches free-draining behavior with a monotonic increase of flow birefringence with increasing shear rate instead of the distinct onset point usually observed. These low ionic-strength solutions also exhibit overshoots in the birefringence on startup of simple shear flow.</p>
<p>The flow birefringence data have been compared with predictions of the nonlinear elastic dumbbell model with various combinations of constant or conformation-dependent friction laws, internal viscosity, strain-inefficient rotation, and Coulombic charges on the beads. It seems that <i>all</i> of the models studied work well in pure extension where the coil-stretch process largely governed by the limited amount of total strain (or finite residence time) in the flow. However, in flows with considerable vorticity, the details of the hydrodynamic interaction between beads and solvent and the rotational motion of the deforming dumbbell become very important in determining the behavior of the model. Thus the birefringence data in the flows near simple shear flow provide more stringent tests of the models than flows with no vorticity. In flows slightly more extensional than simple shear flow, none of the more advanced models gives entirely satisfactory comparisons with the data. In this flow regime, the best comparisons with data are obtained with the simple FENE dumbbell. Some evidence that the current modeling approach (and conformation-dependent hydrodynamic friction) is basically sound was found. The charged dumbbell model is able to describe the large difference in behavior between highly charged polyelectrolytes and those with excess added salt only if a conformation-dependent friction law is included.</p>https://thesis.library.caltech.edu/id/eprint/1046Birefringence of Polymer Solutions in Time Dependent Flows
https://resolver.caltech.edu/CaltechETD:etd-02232007-154744
Authors: {'items': [{'id': 'Geffroy-Aguilar-Enrique', 'name': {'family': 'Geffroy Aguilar', 'given': 'Enrique'}, 'show_email': 'NO'}]}
Year: 1990
DOI: 10.7907/gpt7-3556
<p>This is a study of changes of conformation of macromolecules in polymeric solutions which are subjected to time-dependent extensional flows generated by a two-roll mill flow device. The flows produced by the two-roll mill are linear, and two-dimensional. It has a stagnation point at the center of the flow field where the magnitudes of the strain-rates are greater than the vorticity. This study of conformational changes is based on data around the vicinity of the stagnation point, I for steady state flows, and several transient flow histories such as startup, cessation, and double-step flows. We also present an analytical solution for the creeping flow generated by an infinitely long two-roll mill embedded in an unbounded fluid. This solution is used as a benchmark to compare the behavior of the polymer solutions when subjected to flows with different values for the ratio of rate-of-strain to vorticity.</p>
<p>The conformational changes are determined experimentally using the Two-color Flow-Birefringence which provides an instantaneous and point-wise measure of the anisotropy of the fluid, together with the relative orientation of the anisotropy with respect to the principal axes of the flow field. Based on relaxation of the fluid anisotropy the characteristic time-scales of the polymer have been evaluated as a function of the flow field properties and the degree of conformational change of the macromolecules. Data for two polymeric solution is presented. The first polymer system is the so-called test-fluid M1. This polymeric solution is shown to degrade significantly, even for small values of the velocity gradient, as measured by the changes in the macroscopic relaxation time-scales. The second solution is a concentrated polystyrene solution that presents overshoots and undershoots of the polymer conformation dependent of the ratio of vorticity to rate-of-strain. When subjected to large deformations, this polystyrene solution shows not only the possibility of a reduced number of entanglements, but also a significant deformation of the macromolecule segments associated to a shorter relaxation time-scale for the dynamics of concentrated solutions, which corresponds to that predicted by the intermediate relaxation time-scale of Doi-Edwards model.</p>https://thesis.library.caltech.edu/id/eprint/722Time-Temperature Response of Multi-Phase Viscoelastic Solids Through Numerical Analysis
https://resolver.caltech.edu/CaltechETD:etd-10292003-112909
Authors: {'items': [{'email': 'cbrinson@northwestern.edu', 'id': 'Brinson-Lynda-Catherine', 'name': {'family': 'Brinson', 'given': 'Lynda Catherine'}, 'show_email': 'YES'}]}
Year: 1990
DOI: 10.7907/SYAS-2A50
<p>A numerical model has been constructed for the study of the properties of multi-phase viscoelastic composites. The model utilizes the dynamic correspondence principle of viscoelasticity in a finite element program to solve boundary value problems simulating uniaxial tension or simple shear and obtains the global complex Young's or shear moduli of the composite.</p>
<p>Each phase of the composite is considered to be thermorheologically simple. The resulting modulus properties of the composite however, are thermorheologically complex and this investigation examines the nature of time-temperature behavior of multi-phase composite materials. The specific composite considered throughout this study contains viscoelastic inclusions embedded in a different viscoelastic matrix material. The deviation of the composite moduli from thermorheologically simple behavior of the matrix material is shown to occur at frequencies and temperatures where the glass-to-rubber transition of the included phases are reached.</p>
<p>Properties of polystyrene and polybutadiene are used to investigate the thermorheological complexity (non-shiftability) of a Styrene-Butadiene-Styrene (SBS) block copolymer. To achieve congruence of the results with experimental data, it is necessary to consider a transition phase of properties "intermediate" to those of styrene and butadiene. Using accurate physical information on the individual phase properties and on the interphase region, it is possible to utilize the numerical model to predict long term properties of multi-phase composites from short term laboratory data. Lacking detailed information on the properties of a particular phase (e.g., the interphase), but knowing the time dependent properties for the composite material at a broad range of temperatures, it is also possible to use the numerical tool to solve an inverse problem and determine the unknown properties of the phase in question.</p>https://thesis.library.caltech.edu/id/eprint/4297Semi-dilute polymer solutions in strong flows. Part I: Birefringence and flow modification in extensional flows. Part II: Chaotic mixing in time-periodic flows
https://resolver.caltech.edu/CaltechETD:etd-05172007-154209
Authors: {'items': [{'id': 'Ng-R-C', 'name': {'family': 'Ng', 'given': 'Ricky Chiu-Yin'}, 'show_email': 'NO'}]}
Year: 1990
DOI: 10.7907/z6wv-9136
Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.
The non-Newtonian effects of semi-dilute polymer solutions in laminar two-dimensional steady and time-periodic strong flows are examined separately in two parts of this thesis. Strong flows are flows that can induce large deformation of the polymer molecules. The first part of this thesis is the study of flow-induced stretching of macromolecules in semi-dilute solutions and the subsequent modification to extensional flows in a two-roll and a four-roll mill. Experimental results are presented for flow birefringence, which provides a measure of the degree of polymer extension. In addition, we report on velocity gradient measurements via the technique of homodyne light scattering for solutions of various polymer concentrations in the dilute to semi-dilute regime. Model predictions are also discussed using an interacting dumbbell model. In the second part of the thesis, we examine fluid mixing and transport in two-dimensional time-periodic Stokes flows produced in a blinking two-roll mill (BTRM) for both Newtonian and polymer solutions. Here, we report experimental data obtained by the technique of flow visualization using dye tracer, as well as quantitative measurements using a digital imaging technique.
The flow birefringence results for 100, 1500, and 4500 ppm polystyrene in viscous solvents indicate that increasing concentration will inhibit stretching of polymer molecules due to strong intermolecular interactions. The birefringence data for all three solutions correlate with the eigenvalue of the velocity gradient tensor for different extensional flows in the 2-roll and the 4-roll mill. Inception and cessation of steady extensional flows show distinctive overshoots in birefringence for the semi-dilute (1500 and 4500 ppm) solutions. Complementary velocity gradient measurements show a significant inhibition of large strain rates when a sufficient amount of extended polymer is present (the dilute 100 ppm solution shows no flow effect). The onset of polymer-induced changes in the flow (flow modification) occurs at a critical effective volume concentration, [...] ~ 175, based upon the volume of spheres that circumscribe the extended polymer chain, for both semi-dilute solutions. The magnitude of flow modification is larger in the less concentrated 1500 ppm solution due to the competing effects of increasing concentration and the inhibition of polymer extension which tends to lower the effective volume concentration, [...]. The correlation of the magnitude of flow modification with [...] is revealed by the local (pointwise) velocity gradient measurements for different concentration polymer solutions.
Various molecular models for non-dilute polymer solutions are discussed. The best comparison with the present flow birefringence data is obtained from the predictions of an interacting nonlinear elastic dumbbell (FENE-IDB) model. The FENE-IDB model predictions show a smooth transition of dilute solution behavior to semi-dilute solution behavior. In dilute solutions, the birefringence normalized with polymer concentration (or specific birefringence) is independent of concentration, c. However, the specific birefringence is proportional to c(-1) when plotted versus the dimensionless eigenvalue of the velocity gradient tensor, [...], for semi-dilute solutions. We also noted that the relaxation time of polymer, [...], is dependent on c for semi-dilute solutions.
Studies of mixing and fluid transport properties in time-periodic laminar BTRM flows are first performed for Newtonian solutions. Fluid mixing is shown to be either regular or chaotic depending on the characteristic period of oscillation, µ. Chaotic (efficient) mixing is achieved globally in the flow device when µ >= 0.5. The results in the mixing study can be compared qualitatively with dynamical systems theory predictions of chaos in time-periodic vortex-pair flows. The effect of polymer (a 1500 ppm solution of polystyrene in viscous solvent) on chaotic mixing and fluid transport in the BTRM flows is an O(1) decrease in both the area of mixing and the rate of fluid transport between different regions of the flow when compared with the corresponding Newtonian data. The onset of the polymer effect on the flow occurs at a critical Deborah number of (De)c ~ 2. This high De effect may be related to polymer-induced changes to both the weak and strong flow regions in the BTRM since the time-periodic flow is alternatively strong and mostly weak in the Lagrangian frame of reference.https://thesis.library.caltech.edu/id/eprint/1850Computer mediated communication
https://resolver.caltech.edu/CaltechETD:etd-12072007-090605
Authors: {'items': [{'email': 'cit-thesis@remy.sanouillet.com', 'id': 'Sanouillet-R-D', 'name': {'family': 'Sanouillet', 'given': 'Remy D.'}, 'show_email': 'YES'}]}
Year: 1994
DOI: 10.7907/THJT-R127
<p>What will the age of the telephone-computer be like? In this thesis we present an answer to this question. We will base this answer on a conceptual framework being developed by the research group in which this work has been done, namely the Caltech/NCR Project; the work of this Project is embodied in the New World of Computing System. This framework will be stated as a paradigm for human information activities.</p>
<p>The main contributions of this thesis are, first, an examination of the implications of this framework for the communication aspects of information processing. The second is the design of the communication aspects of the New World of Computing System, reflecting the results of this examination. The System, in its totality, provides a computer environment for the telephone-computer age.</p>
https://thesis.library.caltech.edu/id/eprint/4846