Physical Sciences and Mathematics Commons^™

"Effect Of Zinc And Strontium Dopants On The Structure And Stability Of Hydroxyapatite At High Temperatures", Dylan Correll Smith

College of Science and Health Theses and Dissertations

Hydroxyapatite (HA) is a bioceramic that synthetically mimics human bone. It is commonly used in medical applications as a filler for damaged bone, and in procedures such as dental implants and hip replacements. Doping of HA with elements such as zinc and strontium is known to increase the bioactivity of HA, as well as increase the retention and adsorption of therapeutic molecules for drug delivery. High-temperature, in-situ X-ray diffraction data were measured on 10 at. % zinc-doped, 10 at. % strontium-doped, and undoped HA powders at the Advanced Photon Source at Argonne National Laboratory. This research studied the temporal and …

Development Of A Strontium-87 Ion Interferometer, Christopher Joseph Erickson

Theses and Dissertations

I present the construction of a low-velocity intense source (LVIS) of laser-cooled neutral strontium using permanent ring magnets. The LVIS consists of a magneto-optical trap from which cold strontium is extracted in a well-collimated beam. I also present the development and implementation of a full suite of low-noise, high-bandwidth laser control electronics including a microcontroller unit. This microcontroller remotely controls and monitors the current driver, temperature controller, and PID lock circuit for each diode laser simultaneously. The current driver output is accurate to within 2 micro-amps and repeatable to with a few nano-amps. The noise spectral density of the current …

Modeling Of Compositionally Graded Barium Strontium Titanate From First Principles, Laura Elizabeth Walizer

Graduate Theses and Dissertations

"Barium Strontium Titanate (BaxSr1-xTiO3 or BST) is a Perovskite alloy of interest for both technological and intellectual reasons. Its ferroelectric and piezoelectric properties make it useful in a variety of electric components such as transducers and actuators, and BST in particular is a material of interest for the development of a ferroelectric RAM for computers. The inclusion of SrTiO3, an incipient ferroelectric, and the fact that the properties of a BST system depend strongly on its relative composition of BaTiO3 and SrTiO3 (ST), make also this a material of high interest. Compositionally graded systems are of further interest , partly …

Evaluation Of Cs/Sr Waste Form For Long Term Storage And Disposal, Gary Cerefice

Waste Forms Campaign (TRP)

The goal of this project is to examine the potential long term performance of the proposed aluminosilicate waste/storage form for the isolation and eventual direct disposal of the cesium and strontium separated from recycled nuclear fuel. In the first phase of this work, researchers will investigate the sintering procedure to prepare the drum-like aluminosilicate waste/storage form from the as-received aluminosilicate powder, and then examine the basic physical properties, phase structure and microstructure of the sintered aluminosilicate with /without mixing solution with several ppm Cs/Sr. In the second phase, researchers will evaluate the interaction of the proposed waste form with structural …

Evaluation Of Cs/Sr Waste Form For Long Term Storage And Disposal, Gary Cerefice, Longzhou Ma

Waste Forms Campaign (TRP)

The goal of this project is to examine two potential concerns regarding the long-term performance of a proposed cesium/ strontium waste form. To facilitate long-term storage, up to 300 years, the disposal containers will need to be able to survive for the entire storage interval. The first aspect of the project will explore the potential interaction of the aluminosilicate waste form with the storage canister materials to determine if there is any corrosion or chemical interaction concerns for the storage of the materials.

At the end of the storage interval, most of the 137Cs in the waste form will have …

Broadening And Shifting Of Atomic Strontium And Diatomic Bismuth Spectral Lines, Jeremy C. Holtgrave

Theses and Dissertations

The objective of this research is to study the effects of noble gases on atomic strontium and diatomic bismuth visible transitions, Specifically, this research seeks to determine if the line broadening and, in the case of atomic strontium, line shifting rates of these transitions in the presence of noble gases depend on the total angular momenta of the energy states involved. It has been known for more than a century that atomic and molecular spectral lines are broadened and shifted by perturbing species. While a considerable body of theoretical work has been accomplished on this topic over the years, only …