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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effect of mobile phase additives on linearity in particle beam lc/ms /

Perry, Mary Laura, January 1991 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 112-118). Also available via the Internet.
2

A determination of multiple scattering for a negative pion beam

Watts, Larry James January 1978 (has links)
The multiple Coulomb scattering of negative pions has significant effects on the dose distributions resulting from pion beams incident on thick targets. The use of negative pions in radiotherapy requires a detailed knowledge of the distribution of dose and biological effect. Thus it is important to have an accurate description for the lateral distributions of pions which result from multiple scattering. It has been proposed by Fowler and Perkins that these lateral distributions are of a Gaussian nature for incident pencil beams. In this study an attempt has been made to determine experimentally and theoretically the appropriate value for the standard deviation of the Gaussian in the pencil beam description. The experimental determination involved placing medical x-ray films in a homogeneous water phantom, perpendicular to the beam axis of the M8 biomedical channel at TRIUMF. The distributions recorded on film for circularly collimated beams were measured for optical density and compared to calculated distributions in order to extract the pencil beam information. The presence of contaminating electrons and muons as well as the difficulty in achieving a parallel beam complicated the determination of the standard deviation of the Gaussian for pions. The experimental determination at the end of a 20.1 cm range in water is only 7% greater than the preferred theoretical calculation for pions alone. This calculation is based on the first (Gaussian) term of Moliere’s theory modified for the Fano correction and energy loss and yields results 20% lower than those of the "standard reference" of Fowler and Perkins. The agreement between the theory for pions and the experiment for a real beam in water indicates that the theory presented should be adequate for treatment planning calculations. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
3

RELATIVE AND ABSOLUTE LEVEL POPULATIONS OF BEAM-FOIL EXCITED NEUTRAL HELIUM

Davidson, June Fjord, 1943- January 1974 (has links)
No description available.
4

High energy bremsstrahlung from proton-nucleus collisions

Beckham, Walter Carl, January 1962 (has links)
Thesis (Ph. D. in Physics)--University of California, Berkeley, Aug. 1962. / TiD-4500 (18th Ed.). Bibliography: p. 95.
5

Mass discrimination in a mass spectrometer system and a supersonic molecular beam sampling system Excited states in the ionization process of alkyl olefins and 2-pentanone /

Wood, Karl Vernon. January 1978 (has links)
Thesis--Wisconsin. / Vita. Includes bibliographical references.
6

Dynamics of a flexible extendible beam

Stylianou, Marinos Costa 05 July 2018 (has links)
Axially-moving materials arise in problems associated with spacecraft antennas, pipes conveying fluid and telescopic robotic manipulators. Flexible extendible beams are a special class of axially-moving materials, in which the axially-moving material is modelled as a slender beam and the mechanism of elastic deformation is transverse bending. Hamilton's principle is used to derive the governing differential equation of motion and system invariant properties of a flexible extendible beam protruding from a rigid wall with prescribed extrusion profile. The mass of the system is not constant and the general analytical solution to the equation of motion is not known. In this study, numerical solutions are obtained using finite-element analysis. However, instead of following the obvious (but cumbersome) approach of using fixed-size elements and increasing their number, in a stepwise fashion, as mass elements enter the domain of interest, a more elegant approach is followed wherein the number of elements is fixed, while the sizes of the elements change with time. To this end, a variable-domain beam finite element whose size is a prescribed function of time is formulated. The accuracy of this variable-domain beam element is demonstrated through the time-integration of equations of motion using various extrusion profiles. Additional verification is performed by the evaluation of the system's invariant quantities, comparison with a special analytical solution, and the dynamic stability analysis of pipes conveying fluid. The effects of wall flexibility, tip mass, and high-frequency axial-motion perturbations to the transverse response of the flexible extendible beam are also examined. In order to gain a deeper insight into the mechanics of this system, the dynamic stability characteristics of the flexible extendible beam are also investigated using various extrusion profiles. The effects of physical damping, tip mass, tip support and wall flexibility on the stability characteristics of this system are examined. The power and versatility of this finite-element formulation is demonstrated in a simulation of an extruding flexible extendible beam which carries a tip mass and protrudes from a flexible envelope beam which imparts three-dimensional rigid-body rotations to the system. / Graduate
7

A high statictics study of [omega] production /

Shaevitz, Michael Herman January 1975 (has links)
No description available.
8

Neutron resonance cross section analysis in filtered neutron beams

Bohl, William Raymond, January 1971 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
9

Experimental studies on particle damping technology for electronics manufacturing equipment.

January 2002 (has links)
Chan Kwong-wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 85-87). / Abstracts in English and Chinese. / LIST OF FIGURES --- p.vii / LIST OF TABLES --- p.xi / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Vibration Control --- p.1 / Chapter 1.1.2 --- Passive Damping and Particle Damping Technology --- p.2 / Chapter 1.2 --- Literature Review --- p.4 / Chapter 1.3 --- Research Objective --- p.7 / Chapter 1.4 --- Organization of the Thesis --- p.7 / Chapter 2 --- PARTICLE DAMPING CHARACTERISTICS AND FEASIBILITY --- p.9 / Chapter 2.1 --- Particle Damping Characteristics --- p.9 / Chapter 2.1.1 --- Energy Balance in SDOF System --- p.9 / Chapter 2.1.2 --- Energy Dissipation Mechanisms in Particle Damping --- p.10 / Chapter 2.2 --- Particle Damping Feasibility --- p.15 / Chapter 2.2.1 --- Cantilever Beam Experiment with Free Vibration --- p.15 / Chapter 2.2.2 --- Effectiveness of Particle Damping --- p.17 / Chapter 3 --- A STUDY ON PACKING RATIO AND GRANULE SIZE --- p.19 / Chapter 3.1 --- Experimental Setup --- p.19 / Chapter 3.2 --- Effect of Packing Ratio --- p.23 / Chapter 3.3 --- Effect of Granule Size --- p.24 / Chapter 3.4 --- Damping Ratio Estimation --- p.25 / Chapter 3.5 --- Trends of Damping Ratio against Packing Ratio --- p.28 / Chapter 3.6 --- Trends of Damping Ratio against Granule Size --- p.32 / Chapter 3.7 --- Conclusions --- p.35 / Chapter 4 --- APPLICATION OF PARTICLE DAMPING ON BOND ARM --- p.36 / Chapter 4.1 --- Identification of Structural Vibration --- p.37 / Chapter 4.2 --- Finite Element Modeling --- p.39 / Chapter 4.2.1 --- Model of Bond Arm --- p.39 / Chapter 4.2.2 --- Material Properties --- p.40 / Chapter 4.2.3 --- Modes of Frequencies --- p.40 / Chapter 4.2.4 --- Mode Shapes of Bond Arm --- p.41 / Chapter 4.3 --- Experimental Setup and Procedure --- p.41 / Chapter 4.4 --- Design of Particle Enclosure --- p.43 / Chapter 4.5 --- System Parametric Study --- p.44 / Chapter 4.5.1 --- Effect of Granule Sizes --- p.44 / Chapter 4.5.2 --- Effect of Packing Ratios --- p.47 / Chapter 4.5.3 --- Effect of Different Materials of Particle Enclosure --- p.50 / Chapter 4.5.4 --- Effect of Structural Form of Enclosure --- p.52 / Chapter 4.5.5 --- Effect of Number of Chambers Filled --- p.53 / Chapter 4.5.6 --- Effect of Different Locations of Particle Enclosure --- p.55 / Chapter 4.6 --- Conclusions --- p.56 / Chapter 5 --- TEST AND ANALYSIS OF BOND HEAD STAND WITH PARTICLE DAMPING --- p.57 / Chapter 5.1 --- Ways of Implementation --- p.58 / Chapter 5.1.1 --- Factor of Mode Shape --- p.59 / Chapter 5.1.2 --- Stress Concentration Analysis --- p.59 / Chapter 5.2 --- Experimental Setup --- p.60 / Chapter 5.3 --- Bond Head Stand with Small Force Excitation --- p.62 / Chapter 5.3.1 --- Measurement Data --- p.62 / Chapter 5.4 --- Bond Head Stand with Large Force Excitation --- p.70 / Chapter 5.5 --- Effect of Packing Ratio at Different Frequency Ranges --- p.71 / Chapter 5.6 --- Discussions --- p.80 / Chapter 6 --- CONCLUSION --- p.82 / Chapter 6.1 --- Summary --- p.82 / Chapter 6.2 --- Future Work --- p.84 / BIBLIOGRAPHY --- p.85 / APPENDIX
10

Simulations of a novel accelerator of intense ion beams for high energy density physics studies. / 作高能量密度物理研究的一種新型強離子束加速器的模擬 / Simulations of a novel accelerator of intense ion beams for high energy density physics studies. / Zuo gao neng liang mi du wu li yan jiu de yi zhong xin xing qiang li zi shu jia su qi de mo ni

January 2009 (has links)
Ling, Chi Yeung = 作高能量密度物理研究的一種新型強離子束加速器的模擬 / 凌子陽. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. 111-114). / Abstracts in English and Chinese. / Ling, Chi Yeung = Zuo gao neng liang mi du wu li yan jiu de yi zhong xin xing qiang li zi shu jia su qi de mo ni / Ling Ziyang. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.7 / Chapter 2.1 --- High Energy Density Physics and Warm Dense Matter --- p.7 / Chapter 2.1.1 --- Definition of HEDP and WDM --- p.7 / Chapter 2.1.2 --- The physics of WDM --- p.9 / Chapter 2.1.3 --- Advantages of the ion beam approach --- p.10 / Chapter 2.2 --- Intense low energy ion beam machines requirements for NDCX-II --- p.12 / Chapter 2.3 --- Neutralized Drift Compression Experiment (NDCX) --- p.14 / Chapter 2.3.1 --- Neutralized Transport Experiment (NTX) --- p.15 / Chapter 2.3.2 --- The first NDCX --- p.18 / Chapter 2.4 --- Accelerator architectures proposed for NDCX-II --- p.20 / Chapter 2.4.1 --- Radio Frequency Linear Accelerator (RF Linac) --- p.20 / Chapter 2.4.2 --- Electrostatic accelerator --- p.23 / Chapter 2.4.3 --- Drift Tube Linac (DTL) --- p.23 / Chapter 2.4.4 --- Linear Induction Accelerator (induction linac) --- p.24 / Chapter 2.5 --- Pulse Line Ion Accelerator --- p.25 / Chapter 2.6 --- Review on tests of Pulse Line Ion Accelerator --- p.30 / Chapter 2.7 --- Simulation codes --- p.32 / Chapter 2.7.1 --- 3-D Electromagnetic code MAFIA --- p.33 / Chapter 2.7.2 --- Particle-in-cell code WARP --- p.35 / Chapter 2.8 --- Envelope equation of ion beam and beam diagnostics --- p.37 / Chapter 3 --- Investigations on insulator breakdown in the PLIA --- p.40 / Chapter 3.1 --- Modeling in MAFIA --- p.40 / Chapter 3.2 --- Scaling Law --- p.42 / Chapter 3.3 --- Investigation of different frequency modes near insulator surface --- p.46 / Chapter 3.4 --- Standing wave effect in PLIA --- p.50 / Chapter 3.5 --- Conclusion --- p.52 / Chapter 4 --- PLIA based design for the second Neutralized Drift Compression Experiment --- p.55 / Chapter 4.1 --- The injector --- p.56 / Chapter 4.2 --- Pulse Line Ion Accelerator sections --- p.60 / Chapter 4.2.1 --- Basic design strategy --- p.60 / Chapter 4.2.2 --- Simulation results of PLIA sections --- p.69 / Chapter 4.3 --- Neutralized Drift Compression Section --- p.77 / Chapter 4.3.1 --- Drift length --- p.78 / Chapter 4.3.2 --- First focusing solenoid --- p.80 / Chapter 4.3.3 --- Plasma-filled region --- p.84 / Chapter 4.3.4 --- Final focusing solenoid and the best focal point --- p.88 / Chapter 4.3.5 --- Sensitivity to drift length and focusing strength --- p.91 / Chapter 4.4 --- Conclusion --- p.92 / Chapter 5 --- Other Pulse Power Options --- p.94 / Chapter 5.1 --- The injector and the beamline --- p.95 / Chapter 5.2 --- 3-meter electrostatic column --- p.97 / Chapter 5.3 --- Induction linac --- p.100 / Chapter 5.4 --- Hybrid of induction linac and Pulse Line Ion Accelerator --- p.104 / Chapter 5.5 --- Conclusion --- p.107 / Chapter 6 --- Discussions --- p.108 / Chapter 6.0.1 --- Future development of PLIA --- p.110 / Bibliography --- p.111

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