Physical Sciences and Mathematics Commons^™

A Spectroscopic And Photometric Survey Of The W4 Hii Region And Its Young Stellar Population, Matt Wentzel-Long

Dissertations

The W4 HII region is home to a large number of O and B-type stars as well as the young open cluster IC 1805. OB-type produce intense photoionizing radiation and stellar winds that can induce star formation in surrounding molecular clouds and sometimes carve out large regions of decreased particle density called superbubbles. During the star formation process, young stellar objects (YSOs) are initially surrounded by circumstellar disks made of gas and dust which naturally dissipate after several million years. The dissipation of the disk is thought to occur for a variety of reasons, including photoevaporation by the encompassed protostar …

Synthesis Of Biologically Active Phosphorus Heterocycles, Giri Gnawali

Dissertations

This dissertation work is divided into two parts. The first part is focused in the development of methodology for the synthesis of phostones and phosphonosugars and advancement thereof. The second part is focused in the development of affinity probes based on analogs of natural products cyclophostin and the cyclipostins.

Phostone (3) and phosphonosugars are cyclic phosphonates. The anomeric carbon of sugar is replaced by a phosphorus atom. The synthesis of phostones has been achieved starting form the key intermediate, γ,δ-epoxy vinyl phosphonate (1). The palladium catalyzed ring opening of γ,δ-epoxy vinyl phosphonates by a nucleophile results …

Construct Local Quasi-Interpolation Operators Using Linear B-Splines, Abeer Alzahrani

Dissertations

The data interpolating problem is a fundamental problem in data analysis, and B-splines are frequently used as the basis functions for data interpolation. In the real-world applications, the real-time processing is very important. To achieve that, we cannot use any matrix inversion for large amount of data, and we also need to avoid using any global operator. To solve this problem, we develop a new method based on a local quasi-interpolation operator. To construct the local quasi-interpolation operator, we need to factorize the Shoenberg-Whitney matri- ces for the given data samples. Furthermore, our local quasi-interpolation operator should correspond to a …

New Catalytic Reactions In Carbohydrate Chemistry, Scott Geringer

Dissertations

Carbohydrates or sugars are some of the most diverse and abundant biological molecules. They are involved in a multitude of processes in the body such as fertilization, cell-cell communication, and cancer metathesis. Because of these vital functions, the study of sugars is rapidly growing field. The field however is limited due to the complex nature of sugars which results in difficulties in obtaining large quantities for study.

Protecting group manipulation is a large emphasis area in carbohydrate chemistry due to the need to selectively protect different functional groups of each molecule during synthesis. Catalytic and selective cleavage of protecting groups …

High-Order Adaptive Synchrosqueezing Transform, Jawaher Alzahrani

Dissertations

The prevalence of the separation of multicomponent non-stationary signals across many elds of research makes this concept an important subject of study. The synchrosqueezing transform (SST) is a particular type of reassignment method. It aims to separate and recover the components of a multicomponent non-stationary signal. The short time Fourier transform (STFT)-based SST (FSST) and the continuous wavelet transform (CWT)based SST (WSST) have been used in engineering and medical data analysis applications. The current study introduces the dierent versions of FSST and WSST to estimate instantaneous frequency (IF) and to recover components. It has a good concentration and reconstruction for …