Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone ({phi}/{psi}) dihedral angles by comparing experimentally determined {sup 13}C{sub a}, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized …

One of the major motivators of this work is the Mercury Project, which is a 1 kW scalable diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL). Major goals include 100 J pulses, 10% wallplug efficiency, 10 Hz repetition rate, and a 5 times diffraction limited beam. To achieve these goals the Mercury laser incorporates ytterbium doped Sr{sub 5}(PO{sub 4}){sub 3}F (S-FAP) as the amplifier gain medium. The primary focus of this thesis is a full understanding of the properties of this material which are necessary for proper design and modeling of the system. Ytterbium doped fluorapatites, which were previously investigated at LLNL, were found to be ideal candidate materials for a high power amplifier systems providing high absorption and emission cross sections, long radiative lifetimes, and high efficiency. A family of barium substituted S-FAP crystals were grown in an effort to modify the pump and emission bandwidths for application to broadband diode pumping and short pulse generation. Crystals of Yb{sup 3+}:Sr{sub 5-x}Ba{sub x}(PO{sub 4}){sub 3}F where x < 1 showed homogeneous lines offering 8.4 nm (1.8 times enhancement) of absorption bandwidth and 6.9 nm (1.4 times enhancement) of emission bandwidth. The gain saturation fluence of Yb:S-FAP …

The authors present the results of a new measurement of the t{anti t} production cross section using e{mu} channel in p{anti p} collisions at {radical}s = 1.8 TeV. This study corresponds to an integrated luminosity of 108.3 {+-} 5.7 pb{sup {minus}1} acquired by the D0 detector during the Fermilab Tevatron Collider Run 1 (1992--1996). By using neural network techniques instead of the conventional analysis methods, the authors show that the signal acceptance can be increased by 10% (for m{sub t} = 172 GeV/c{sup 2}) while the background remains constant. Four e{mu} events are observed in data with an estimated background of 0.22 {+-} 0.14 corresponding to a t{anti t} production cross section of 9.75 {+-} 5.53 pb.

We attempt to identify a single top signal in the muon + jets data collected using the D0 detector at the Fermilab Tevatron at a center-of-mass energy of {radical}s = 1.8 TeV from 1992-96. The data corresponds to an integrated luminosity of 103.7 pb{sup -1}. While resolving a signal has proved impossible, we are able to place an upper limit on the production cross section for single top events using these data. The cross section for production of single top via 95% p{bar p} {yields} tb and p{bar p} {yields} qtb is less than 78 pb at the 95% confidence level based on muon + jets data only.

Groundwater irrigation is critical to food production and, in turn, to humankind's relationship with its environment. The development of groundwater in Santa Clara Valley, California during the early twentieth century is instructive because (1) responses to unsustainable resource use were largely successful; (2) the proposals for the physical management of the water, although not entirely novel, incorporated new approaches which reveal an evolving relationship between humans and the hydrologic cycle; and (3) the valley serves as a natural laboratory where natural (groundwater basin, surface watershed) and human (county, water district) boundaries generally coincide. Here, I investigate how water resources development and management in Santa Clara Valley was influenced by, and reflective of, a broad understanding of water as a natural resource, including scientific and technological innovations, new management approaches, and changing perceptions of the hydrologic cycle. Market demands and technological advances engendered reliance on groundwater. This, coupled with a series of dry years and laissez faire government policies, led to overdraft. Faith in centralized management and objective engineering offered a solution to concerns over resource depletion, and a group dominated by orchardists soon organized, fought for a water conservation district, and funded an investigation to halt the decline of well …

This dissertation reports on measurements of inclusive cross sections times branching fractions into electrons for W and Z bosons produced in p{anti p} collisions at {radical}s = 1.8 TeV. From an integrated luminosity of 84.5 pb{sup {minus}1} recorded in 1994--1995 by the D0 detector at the Fermilab Tevatron {Lambda} the cross sections are measured to be {sigma}p{anti p} {r_arrow} W + X {center_dot} B(W {r_arrow} e{nu}) = 2,310 {+-} 10 (stat) {+-} 50 (Syst) {+-} 100 (lum) pb and {sigma}(p{anti p} {r_arrow} Z + X) {center_dot} B(Z {r_arrow} ee) = 221 {+-} 3 (stat) {+-} 4 (Syst) {+-} 10 (lum) pb. The cross section ratio R is determined to be {sigma}(p{anti p} {r_arrow} W + X) {center_dot} B(W {r_arrow} e{nu})/{sigma}(p{bar p} {r_arrow} Z + X) {center_dot} B(Z {r_arrow} ee) = 10.43 {+-} 0.15 (stat) {+-} 0.20 (syst) {+-} 0.10 (NLO){Lambda} and R is used to determine B(W {r_arrow} e{nu}) = 0.1044 {+-} 0.0015 (stat) {+-} 0.0020 (syst) {+-} 0.0017 (theory) {+-} 0.0010 (NLO){Lambda} and {Lambda}{sub W} = 2.169 {+-} 0.031 (stat) {+-} 0.042 (syst) {+-} 0.041 (theory) {+-} 0.022 (NLO) GeV. The latter is used to set a 95% confidence level upper limit on the partial decay width of the …

The study of the exocrine pancreatic acinar cell has been central to the development of models of many cellular processes, especially of protein transport and secretion. Traditional methods used to examine this system have provided a wealth of qualitative information from which mechanistic models have been inferred. However they have lacked the ability to make quantitative measurements, particularly of the distribution of protein in the cell, information critical for grounding of models in terms of magnitude and relative significance. This dissertation describes the development and application of new tools that were used to measure the protein content of the major intracellular compartments in the acinar cell, particularly the zymogen granule. Soft x-ray microscopy permits image formation with high resolution and contrast determined by the underlying protein content of tissue rather than staining avidity. A sample preparation method compatible with x-ray microscopy was developed and its properties evaluated. Automatic computerized methods were developed to acquire, calibrate, and analyze large volumes of x-ray microscopic images of exocrine pancreatic tissue sections. Statistics were compiled on the protein density of several organelles, and on the protein density, size, and spatial distribution of tens of thousands of zymogen granules. The results of these measurements, and …

The Standard Model predicts that the lifetime of the top quark is shorter than the typical time scale at which hadronization process occurs, and the spin information at its production is preserved. Spin correlation of the t{anti t} system from p{anti p} collisions at the Tevatron is analyzed using 6 events in the dilepton channels collected using the D0 detector. Spin correlation factor of {kappa} > {minus} 0.25 at 68% CL is obtained from the data.