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http://hdl.handle.net/1903/24737
Lie Algebraic Methods for Treating Lattice Parameter Errors in Particle Accelerators
Healy, Liam Michael
Orbital dynamics in particle accelerators, and ray tracing in light
optics, are examples of Hamiltonian systems. The transformation from
initial to final phase space coordinates in such systems is a symplectic
map. Lie algebraic techniques have been used with great success in the
case of idealized systems to represent symplectic maps by Lie
transformations. These techniques allow rapid computation in tracking
particles while maintaining complete symplecticity, and easy extraction
of analytical quantities such as chromaticities and aberrations.
Real accelerators differ from ideal ones in a number of ways.
Magnetic or electric devices, designed to guide and focus the beam, may
be in the wrong place or have the wrong orientation, and they may not
have the intended field strengths. The purpose of this dissertation is
to extend the Lie algebraic techniques to treat these misplacement,
misalignment and mispowering errors.
Symplectic maps describing accelerators with errors typically have
first-order terms. There are two major aspects to creating a Lie
algebraic theory of accelerator errors: creation of appropriate maps
and their subsequent manipulation and use.
There are several aspects to the manipulation and use of symplectic
maps. A first aspect is particle tracking. That is, one must find how
particle positions are transformed by a map. A second is concatenation,
the combining of several maps into a single map including nonlinear
feed-down effects from high-order elements. A third aspect is the
computation of the fixed point of a map, and the expansion of a map
about its fixed point. For the case of a map representing a full turn
in a circular accelerator, the fixed point corresponds to the closed
orbit.
The creation of a map for an element with errors requires the
integration of a Hamiltonian with first-order terms to obtain the
corresponding Lie transformation. It also involves a procedure for the
complete specification of errors, and the generation of the map for an
element with errors from the map of an ideal element.
The methods described are expected to be applicable to other
electromagnetic systems such as electron microscopes, and also to light
optics systems.
1986-01-01T00:00:00ZA STUDY OF THE EFFECTIVENESS OF SIMULTANEOUS ORAL PRODUCTION AND THE TOTAL PHYSICAL RESPONSE STRATEGY ON THE SPEAKING ACHIEVEMENT, ATTITUDES MOTIVATION, AND INTEREST OF LEVEL I SPANISH STUDENTS
http://hdl.handle.net/1903/24736
A STUDY OF THE EFFECTIVENESS OF SIMULTANEOUS ORAL PRODUCTION AND THE TOTAL PHYSICAL RESPONSE STRATEGY ON THE SPEAKING ACHIEVEMENT, ATTITUDES MOTIVATION, AND INTEREST OF LEVEL I SPANISH STUDENTS
Haley, Marjorie Hall
Total Physical Response (TPR) is a teaching strategy
in which students learn a foreign language by physically
acting out teacher-directed commands. The TPR instruction
strategy is based on asking the students to be silent,
to listen carefully to commands and then to physically
respond. The TPR strategy allows students to take
an "active" part rather than an "observational" part
in the learning process. It was the purpose of this
study to examine this issue from three perspectives:
1. whether first year foreign language students
achieve higher in the skill of speaking if they are
in action while learning selected Level I objectives; and
2. the impact of delayed oral response in a pure
TPR strategy as compared to inclusion of a speaking
component in a modified version of TPR.
3. whether there were differences in the speaking
achievement between middle school and senior high school
Level I foreign language students who were taught via
the pure TPR and modified TPR strategy.
The sample was comprised of 178 Level I Spanish
students from three secondary schools in a suburban
Baltimore school district. Two of the participating
schools were Middle schools - grades six through eight.
The third school was a Senior high school - grades
nine through twelve. Subjects were randomly assigned
to the experimental condition.
Subjects were pretested at the onset of the study.
The measurement was designed to predict potential success
or failure in learning a foreign language. Additionally,
subjects completed:
(1) the speaking section of a bilingual syntax measure
to assess their level of foreign language competency;
(2) an attitude and motivation battery designed to
measure attitude and motivation related to second language
learning; and (3) a teacher-prepared perception questionnaire
for assessing subject's perception and preference
of being taught via different teaching strategies.
The findings of this study revealed that the two
Pure TPR groups achieved the highest mean scores on
all evaluative measures. The ten hours of delayed
oral practice experienced by both Pure TPR groups provided
valuable comprehension training for these students.
The advantage of providing this listening period became
apparent in higher evaluative scores as evidenced at
both the senior high and middle school level. Furthermore,
the finding s of the present investigation suggest that
the use of "active" learning as opposed to "observational"
learning in the foreign language classroom can be part
of an effective strategy for language instruction.
1986-01-01T00:00:00ZThe Genesis of American-Persian Relations, 1883-1904
http://hdl.handle.net/1903/24735
The Genesis of American-Persian Relations, 1883-1904
Grunwald, Frank Herbert
This thesis discusses the causes which led to diplomatic
representation on the part of the United States in Persia,
the means by which such representation was established, and
the first twenty years or so of its history. It covers the
l imitations of this relationship due to the American foreign
policy of the time, that of non-involvement and non-interference
in the domestic affairs of Persia, and the positive contribution
made by American missionaries in furthering friendly
relations between the two countries. The thesis shows how
America's lack of interest in Persia was contrasted with the
Persian drive to enlist United States support in strengthening
its ability to resist economic and political pressure, mainly
from Russia, and how the Department of State repeatedly turned
aside all advances made by Persia through the United States
minister in Teheran and offered no encouragement to American
business to become established there. It deals with the attitude
of Kurdish tribesmen toward Persian Christians, American
missionaries, and the Persian central authority, and how
their attitude influenced American diplomatic relations.
1978-01-01T00:00:00ZNumerical Solutions for Two- and Three-Dimensional Non-Reacting Flowfields in an Internal Combustion Engine
http://hdl.handle.net/1903/24734
Numerical Solutions for Two- and Three-Dimensional Non-Reacting Flowfields in an Internal Combustion Engine
Griffin, Michael Douglas
The numerical solution for the flowfield established in a spark-
ignition internal combustion engine during the four-stroke (intake,
compression, power, exhaust) cycle is considered. Only fluid-dynamic
effects are treated with combustion simulated by constant- volume heat
addition near top-dead-center on the compression stroke. The working
fluid is assumed to be air of constant specific heat, with both viscous
and inviscid models considered. Two- and three-dimensional engine models
are examined, with the three-dimensional models including both rectangular
and cylindrical geometries. The difficulties associated with obtaining
numerical solutions in cylindrical coordinates for three-dimensional
non-axisymmetric problems when the centerline is included in the region
of interest are discussed. A new method which avoids the coordinate-
singularity problems associated with such cases is presented and used
to obtain the first known four-stroke inviscid-flow solution for a
three- dimensional cylindrical engine model. Similar results are presented
for a three-dimensional rectangular model, and for the first known
two-dimensional four-stroke calculation for a viscous fluid. The inviscid
three-dimensional results are compared with each other and with
previously obtained two-dimensional inviscid-flow calculations. The use
of two-dimensional models is found to be justified for the non- reacting
flowfields considered, since the results obtained from a two-dimensional
calculation in the valve plane are apparently not strongly dependent on
the flowfield perpendicular to the valve plane. It is found that significant
flowfields do exist in all I.C. engine models considered. It is
shown that the unit-cell-Reynolds-number criterion limits viscous flow
calculations to Reynolds numbers of approximately one ten-thousandth
the realistic value, and that this produces flowfields which are strongly
piston-dominated. In contrast, inviscid results show marked circulatory
patterns, which are more realistic. The velocity patterns which develop
in the three-dimensional cylindrical engine model are shown to exhibit
a marked swirl in planes parallel and perpendicular to the cylinder
axis.
1977-01-01T00:00:00Z