8,660 Works

Experimental investigation of temperature and velocity distribution about a rocket jet

Quentin Robert Whitmore
The purpose of the investigation was to determine the temperature distribution and velocity profile surrounding the wake of a 1500 pound thrust liquid rocket motor. The temperature measurements were restricted to those 500°F and below. The velocities measured were in the region in which the temperature measurements were made. The region in which the temperatures exceeded 500°F was found to be included within a solid angle of ten degrees. The high temperature region was found...

Application of asymptotic expansion procedures to low Reynolds number flows about infinite bodies

Herbert Erwin Hunter
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Several limiting cases for viscous incompressible flow are considered for two examples. The first example considered is that of the flow past an expanding infinite cylinder at an angle of attack. The time dependence of the radius of the cylinder is given by the power law R = [...]. The second example considered is the flow...

Studying material properties on the nanometer scale: instrumental development and applications

Stephen D. O'Connor
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. This thesis describes experimental work designed to understand and manipulate material properties on the nanometer scale. Two strategies have been explored: instrument development and experimental applications. Section I describes work associated with atomic force microscopy, including application studies of human hair morphology and the surface microstructure of a bulk metallic glass [...]. Also included in this...

Biophysics of Extracellular Action Potentials

Carl Gold
The goal of this thesis is to analyze the generation of single unit extracellular action potentials (EAPs), and to explore pertinent issues in the interpretation of EAP recordings. I use the line source approximation to model the EAP produced by individual neurons. I compare simultaneous intracellular and extracellular recordings of CA1 pyramidal neurons in vivo with simulations using the same cells'reconstructions. The model accurately reproduces both the waveform and the amplitude of the EAPs. The...

Supersonic Flutter of Circular Cylindrical Shells

Mervyn Daniel Olson
Various experimental and theoretical studies on the supersonic flutter of circular cylindrical shells are discussed. Results of experiments in the Mach number range 2.5 - 3.5 are presented. Three shells with radius-to-thickness ratios of 2,000 were subjected to radial external pressure loadings and to combinations of axial compressive loading and internal pressurization while in the presence of an external axially-directed supersonic flow. Small amounts of internal pressurization were very stabilizing with respect to flutter, but...

Information aggregation, with application to monotone ordering, advocacy, and conviviality

Ben Klemens
I. Chapter 1 presents a convenient notation for describing methods of aggregating information to form posterior distributions, allowing a description of Bayesian updating and many of the cognitive errors people commit in the lab. Chapter 2 looks at the monotone ordering problem: if the prior distributions are ordered in some manner, what updating operations will preserve that ordering? Bayesian updating is a member of a small class of operators which preserve the monotone likelihood ratio...

Robust Model Predictive Control with a Reactive Safety Mode

John Maurice, III Carson
Control algorithms suitable for online implementation in engineering applications, such as aerospace and mechanical vehicles, often require adherence to physical state and control constraints. Additionally, the chosen algorithms must provide robustness to uncertainty affecting both the system dynamics and the constraints. As further autonomy is built into these systems, the algorithms must be capable of blending multiple operational modes without violating the intrinsic constraints. Further, for real-time applications, the implemented control algorithms must be computationally...

Behavior of concentrated colloidal suspensions by Stokesian dynamics simulation

Thanh Ngoc Phung
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The Stokesian dynamics simulation method is applied to study the behavior of concentrated suspensions of hydrodynamically interacting colloidal particles in a shear flow. The aim of this study is the prediction of suspension macroscopic properties from the microstructure - the temporal and spatial distribution of suspended particles. The macroscopic properties includes the shear viscosity, normal stress...

A threshold gate feed-forward switching net algorithm

Gordon Frierson Hughes
A general algorithm is presented for the efficient computation of feed-forward nets of general threshold gates which realize given bi-valued switching functions. A simplified version of the algorithm is presented for the case of symmetric threshold nets which realize symmetric switching functions. These algorithms produce near-minimal gate nets, and the results of a digital computer program for the general algorithm are presented to illustrate the degree of efficiency and minimality obtained in practice. Both algorithms...

Stability and supersymmetry

Thomas Lynn Curtright
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. PART I A complete account of a perturbative investigation of ground state instability is presented for a massless theory involving scalar, pseudoscalar, and Majorana spinor fields. The effective potential, dimensional regularization, and renormalization group formalisms are briefly reviewed and then applied in detail to show the semiclassical vacuum of the model is unstable due to radiative...

I. The molecular structures of certain organic four-membered ring compounds. II. The BaMg9 structure

Elihu Goldish
Part I presents the results of electron diffraction investigations of some relatively simple four-membered organic ring compounds: trimethylene oxide, 3-methylenetrimethylene oxide, trimethylene sulfide, and cyclobutene. Discussion is given of the bond lengths in these and other small-ring molecules. In a supplementary section are the results of an investigation of dimethyl selenide, which indicates a somewhat larger radius for selenium than is usually given, and preliminary results for decaborane. In Part II the disordered BaMg9 structure...

A spectroscopic investigation of four O-type subdwarfs

Arsine Victoria Peterson
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The spectra of four O-type subdwarfs, of the class with strong nitrogen lines and very weak carbon and oxygen lines, have been studied in some detail. Model atmospheres have been constructed for the stars HZ 44, +25°4655, and HD 127493, and the computed profiles of selected hydrogen and helium lines have been compared with the observed...

A magnetic survey of Sand Canyon for placer deposits, San Gabriel Mountains, California

Peter Dehlinger
A magnetic survey was made in Sand Canyon, which is in the northwestern part of the San Gabriel Mountains, the object being to locate possible placer deposits. The bedrock in this area is an iron rich igneous rock which has been intruded by numerous dikes. The stream gravels consist of large boulders interspersed with highly magnetic sands. Over 200 stations were involved in the survey in which vertical magnetic intensity was measured using a Schmidt-type...

Functionalized polymers and surfaces via ring-opening metathesis polymerization

Isaac Michael Rutenberg
The research presented in this thesis focuses on the preparation of functionalized polymers using olefin metathesis polymerization methods. A portion of this research is also devoted to the development of applications for metathesis-derived polymers. Three distinct types of olefin metathesis polymerizations can be recognized within this work. Ring-opening metathesis polymerization (ROMP) is the most prevalent type, followed by acyclic diene metathesis (ADMET) polymerization and a hybrid of the ROMP and ADMET mechanisms known as ring-opening-insertion...

The theory of a general quantum system interacting with a linear dissipative system

Frank L. Vernon
A formalism has been developed, using Feynman's space-time formulation of non-relativistic quantum mechanics whereby the behavior of a system of interest, which is coupled to other external quantum systems, may be calculated in terms of its own variables only. It is shown that the effect of the external systems in such a formalism can always be included in a general class of functionals (influence functionals) of the coordinates of the system only. The properties of...

Single Mammalian Cell Gene Expression Analysis Using Microfluidics

Joshua Scott Marcus
Single cell gene expression studies hold great promise for deciphering the ubiquitous heterogeneity present in biological organisms. Although much progress has been made in the field, tools to study gene expression (specific and global) in single cells are generally lacking. This thesis describes the development of novel microfluidic technologies and processes capable of processing single cells to first strand cDNA in a parallel fashion, thereby filling a void in the single cell biology field. The...

Chemical reactions of methane and of n-hexane in ballistic piston apparatus

Paul A. Longwell
The results of ballistic piston tests on methane and on n-hexane are described. In the case of methane the calculated reaction temperatures are 2500 to 3500[degrees]R. and maximum pressure range up to 100,000 pounds per square inch. The distribution of reaction products and the amount of reaction are correlated with the reaction conditions. For n-hexane the products are correlated with reaction conditions and in addition reaction rate coefficients were obtained. The decomposition reaction was found...

An Analysis of Errors in the Electric-Analog Computer

William Joseph Dixon
This thesis is the result of work done in connection with the California Institute of Technology Electric­ Analog Computer. Several methods are developed for determining the accuracy of the solutions of various types of problems by electric circuit analogies. These are used to obtain expressions for the errors involved in the solutions of specific examples. The first part deals with the error involved in the solution of problems with continuously distributed physical properties by means...

Part I. Vortex dynamics in wake models. Part II. Wave generation

David J. Hill
In Part I, steady wakes in inviscid fluid are constructed and investigated using the techniques of vortex dynamics. As a generalization of Foppl's flow past a circular cylinder [5], a steady solution is given for flow past an elliptical cylinder of arbitrary aspect ratio (perpendicular or parallel to the flow at infinity) with a bound wake of two symmetric recirculating eddies in the form of a point vortex pair. Linear stability analysis predicts an asymmetric...

Soft X-Rays from the Cygnus Loop

John Charles Stevens
A detailed soft x-ray survey of the Cygnus Loop, obtained from a rocket-borne experiment, provides evidence that the x-ray emission from this supernova remnant is produced by the interaction of a shock wave and the interstellar medium. A spatial map, having 0.5° by 0.5° resolution, of the structure of the Cygnus Loop in 0.2 to 1.5 kev x-rays is presented. The map shows regions of x-ray emission which correlate well with features at radio and...

Fusion cross section measurements for the reactions Nitrogen-14 + Boron-10 and Oxygen-16 + Oxygen-16

Shiu-Chin Wu
Part I: The ^(14)N + ^(10)B fusion reactions have been studied at c.m. energies between 2.9 and 7.5 MeV by measuring the γ-ray yields from the residual nuclei with a Ge(Li) detector. Cross sections were deduced from these yields with the aid of statistical model calculations. ^(14)N + ^(10)B elastic scattering differential cross sections were measured from E_(cm) = 3.3 to 9.1 MeV at θ_(cm) = 74.4° and 90.0°. The fusion cross sections of ^(14)N...

Monopole operators and mirror symmetry in three-dimensional gauge theories

Vadim Aleksandrovich Borokhov
Many gauge theories in three dimensions flow to interacting conformal field theories in the infrared. We define a new class of local operators in these conformal field theories that are not polynomial in the fundamental fields and create topological disorder. They can be regarded as higher-dimensional analogs of twist and winding-state operators in free 2-D CFTs. We call them monopole operators for reasons explained in the text. The importance of monopole operators is that in...

A singularly perturbed linear two-point boundary-value problem

Warren E. Ferguson
We consider the following singularly perturbed linear two-point boundary-value problem: Ly(x) ≡ Ω(ε)D_xy(x) - A(x,ε)y(x) = f(x,ε) 0≤x≤1 (1a) By ≡ L(ε)y(0) + R(ε)y(1) = g(ε) ε → 0^+ (1b) Here Ω(ε) is a diagonal matrix whose first m diagonal elements are 1 and last m elements are ε. Aside from reasonable continuity conditions placed on A, L, R, f, g, we assume the lower right mxm principle submatrix of A has no eigenvalues whose...

Homological interference by ultraviolet inactivated virus in Newcastle disease virus

Marcel Albert Baluda
The present study concerns a quantitative analysis of the interference between the irradiated and the active Newcastle disease virus. The inactivated particles adsorb to the surface of the cells and do not proceed any further. This union induces surface changes which make it impossible for a superinfecting active particle to penetrate into the host cell and to initiate the production of new virus. The more UVI particles that are adsorbed, the faster the interfering reaction...

Frequencies and amplitudes of high-degree solar oscillations

James Morris Kaufman
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Measurements of some of the properties of high-degree solar p- and f- mode oscillations are presented. Using high-resolution velocity images from Big Bear Solar Observatory, we have measured mode frequencies, which provide information about the composition and internal structure of the Sun, and mode velocity amplitudes (corrected for the effects of atmospheric seeing), which tell us...

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