A Study of the Relationships among Student Expectations about Teacher Nonverbal Immediacy, Student Perceptions of Teacher Nonverbal Immediacy, and Affective Learning in Distance Learning and the On-Site Classroom (open access)

A Study of the Relationships among Student Expectations about Teacher Nonverbal Immediacy, Student Perceptions of Teacher Nonverbal Immediacy, and Affective Learning in Distance Learning and the On-Site Classroom

This thesis explored the relationships among three communication variables in college-level instruction: students' expectancy about teachers' nonverbal immediacy, students' actual perceptions of teachers' nonverbal immediacy, and students' affective learning. Community college students enrolled in either distance learning or a traditional classroom course completed pre-course and mid-course questionnaires to indicate their expectations and observations of the nonverbal immediacy behaviors of their teachers. Analysis showed that students expected and perceived less nonverbal immediacy from tele-course teachers than from on-site teachers, but that perceptions significantly exceeded expectations. Research findings indicated that students' expectancies about teachers' nonverbal immediacy may influence the measurement of affective learning.
Date: July 1997
Creator: Witt, Paul L.
System: The UNT Digital Library
Measurements of delayed neutron parameters for U-235 and Np-237 (open access)

Measurements of delayed neutron parameters for U-235 and Np-237

Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and knowledge of parameters used to predict neutron emission rate is essential for establishing reactivity worths. The delayed neutron yields, decay constants, and the absolute yield for the six-group delayed neutrons have been measured for U-235 and Np-237. This experiment has been called for in the forecast of experiments needed to support operations in the US. The bare U-235 metal assembly Godiva IV at the Los Alamos Critical Experiment Facility (LACEF) provided the source of neutrons. Godiva IV generated about 10{sup 7} total fissions in the samples for the infinite and instantaneous irradiation needed to accentuate the shorter and longer-lived groups of delayed neutrons. The detection system used in the experiment consisted of 20 He-3 tubes embedded in a polyethylene cylinder. The delayed neutron activity resulting from the fast neutron-induced fission has been measured. The measured absolute yield for U-235 was determined to be 0.0163 {+-} 0.009 neutrons/fission. This …
Date: July 1997
Creator: Loaiza, D.
System: The UNT Digital Library
Symbolic derivation of high-order Rayleigh-Schroedinger perturbation energies using computer algebra: Application to vibrational-rotational analysis of diatomic molecules (open access)

Symbolic derivation of high-order Rayleigh-Schroedinger perturbation energies using computer algebra: Application to vibrational-rotational analysis of diatomic molecules

Rayleigh-Schroedinger perturbation theory is an effective and popular tool for describing low-lying vibrational and rotational states of molecules. This method, in conjunction with ab initio techniques for computation of electronic potential energy surfaces, can be used to calculate first-principles molecular vibrational-rotational energies to successive orders of approximation. Because of mathematical complexities, however, such perturbation calculations are rarely extended beyond the second order of approximation, although recent work by Herbert has provided a formula for the nth-order energy correction. This report extends that work and furnishes the remaining theoretical details (including a general formula for the Rayleigh-Schroedinger expansion coefficients) necessary for calculation of energy corrections to arbitrary order. The commercial computer algebra software Mathematica is employed to perform the prohibitively tedious symbolic manipulations necessary for derivation of generalized energy formulae in terms of universal constants, molecular constants, and quantum numbers. As a pedagogical example, a Hamiltonian operator tailored specifically to diatomic molecules is derived, and the perturbation formulae obtained from this Hamiltonian are evaluated for a number of such molecules. This work provides a foundation for future analyses of polyatomic molecules, since it demonstrates that arbitrary-order perturbation theory can successfully be applied with the aid of commercially available computer algebra software.
Date: July 1, 1997
Creator: Herbert, J. M.
System: The UNT Digital Library
Measurement of Z{sup 0} lepton coupling asymmetries (open access)

Measurement of Z{sup 0} lepton coupling asymmetries

Polarized Z{sup 0}`s from e{sup +}e{sup {minus}} collisions at the SLAC Linear Collider (SLC) have been used to determine the asymmetry parameters A{sub e}, A{sub {mu}} and A{sub {tau}} from the leptonic decay channels. This is the first direct measurement of A{sub {mu}}. The data have been gathered by the SLC Large Detector (SLD) with the electron polarization averaging 63% during the 1993 data taking period and 77% in 1994-95. A maximum likelihood procedure as well as cross section asymmetries was used to measure the asymmetry parameters from the differential cross sections for equal luminosities of left- and right-handed electron beams. The polarization-dependent muon-pair distributions give A{sub {mu}} = 0.102 {+-}0.034 and the tau-pairs give A{sub {tau}} = 0.195 {+-}0.034. The initial state electronic couplings in all three leptonic channels as well as the final state angular distribution in the e{sup +}e{sup {minus}} final state measure A{sub e} to be A{sub e} = 0.152{+-}0.012. Assuming lepton universality and defining a global leptonic asymmetry parameter A{sub e-{mu}-{tau}} = 0.151{+-}0.011. This global leptonic asymmetry value translates directly into sin{sup 2}{theta}{sub W}{sup eff}=0.2310{+-}0.0014 at the Z{sup 0} pole.
Date: July 1, 1997
Creator: Smy, M.B.
System: The UNT Digital Library