Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Chemistry
The Benefit Of Precise Chemical Shift And Concentration Referencing In Nmr Applications, Ming Huang
The Benefit Of Precise Chemical Shift And Concentration Referencing In Nmr Applications, Ming Huang
Doctoral Dissertations
“In Nuclear Magnetic Resonance (NMR) spectroscopy, the chemical shift and intensity of NMR signals provide critical information about a sample's molecular structure, reaction conditions, and material properties. For the precise determination of structures and properties, it is critical to know sample or reaction conditions such as temperature, pH, concentration, or absolute amount of material. Chemical-shift and signal-intensity calibrations play a key role for extracting the maximum amount of information from NMR experiments. In this dissertation, internal and external reference standards are used to calibrate NMR spectra with respect to chemical shift and signal intensity. Sealed capillary tubes filled with specific …
High Level Thermochemical And Spectroscopic Computations For Molecules Relevant To Combustion And The Atmosphere, Bradley K. Welch
High Level Thermochemical And Spectroscopic Computations For Molecules Relevant To Combustion And The Atmosphere, Bradley K. Welch
Doctoral Dissertations
"Computational thermochemistry can be a complicated multistep process, but in recent years has become an equal partner with experiment. Many important molecules in combustion systems or in the atmosphere (such as short-lived radicals) are difficult to study experimentally. Predicting highly accurate thermochemistry is a key aspect in understanding these species. In this project, computational thermochemistry was developed into an automated streamlined procedure and then used to understand the methyl and ethyl peroxy families of radicals. This effort involved optimizing a standard workflow for computational thermochemistry. Computational thermochemistry generally requires numerous individual calculations whose cost and scalings vary widely. Conducting such …
Accurate Monitoring Of X, Y, And Z Magnetization For Analysis Of Hardware And Pulse Sequence Performance In Nmr Spectroscopy, Emmalou Theresa Schmittzehe
Accurate Monitoring Of X, Y, And Z Magnetization For Analysis Of Hardware And Pulse Sequence Performance In Nmr Spectroscopy, Emmalou Theresa Schmittzehe
Doctoral Dissertations
"A new nuclear magnetic resonance (NMR) imaging protocol has been developed to independently record the x, y, and z components of the nuclear net magnetization at any point in a pulse sequence while eliminating the observation of the other components. This protocol provides an experimental method of tracking magnetization which then can be used in conjunction with theoretical models to scrutinize the predicted outcome of each step in an NMR pulse sequence and potentially find further improvements to their effectiveness and efficiency. The protocol utilizes a rapid rotating-frame imaging pulse-train technique to obtain RF-field (B1) and resonance-offset (ΔB …
Development And Demonstration Of Sampling Techniques For A Chirped Pulse Fourier Transform Microwave Spectrometer, Frank Edward Marshall
Development And Demonstration Of Sampling Techniques For A Chirped Pulse Fourier Transform Microwave Spectrometer, Frank Edward Marshall
Doctoral Dissertations
"With the introduction of the Chirped Pulse-Fourier Transform Microwave Spectrometer in the past decade, it has become possible to rapidly study the rotational spectra of molecules in the gas phase. It is possible to study molecules that are not normally in the gas phase through the use of various sourcing techniques. The development of both the heated nozzle and the laser ablation sourcing techniques allow for the study of liquids and solids, respectively. The design and performance of these sources will be presented in detail and discussed. Additionally, the development of a Multi-Antennae detection scheme, useful in improving overall sensitivity …