Studies Concerning the Production of Lactobacillic Acid in Lactobacillus Plantarum (open access)

Studies Concerning the Production of Lactobacillic Acid in Lactobacillus Plantarum

This study is concerned with certain factors affecting the content of lactobacillic acid in Lactobacillus plantarum. Three main areas of investigation are reported herein. The effects of both the oxygen tension and the pH of the culture medium on the accumulation of lactobacillic acid were determined. In addition, monolayer studies were conducted to determine the influence of cyclopropane fatty acid content on the molecular packing of membrane lipids.
Date: May 1973
Creator: Halper, Laura Ann
System: The UNT Digital Library
A Study of the Synthesis and Reactions of Enol Lactones (open access)

A Study of the Synthesis and Reactions of Enol Lactones

The purpose of this investigation was to study the syntheses of enol lactones and to prepare a series of amide derivatives of these compounds.
Date: August 1959
Creator: Papalos, John George
System: The UNT Digital Library
The Chlorination of Amino Acid in Municipal Waste Effluents (open access)

The Chlorination of Amino Acid in Municipal Waste Effluents

In model reaction systems to test amino acids in chlorinated waste effluents, several amino acids were chlorinated at high chlorine doses. (2000-4000 mg/1). Amino acids present in municipal waste effluents before and after chlorination were concentrated and purified using cation exchange and Chelex resins. After concentration and cleanup of the samples, the amino acids were derivatized by esterification of the acid functional groups and acylation of the amine groups. Identification and quantification of the amino acids and chlorination products was carried out by gas chromatography/mass spectrometry, using a digital computer data system. Analysis of the waste products revealed the presence of new carbon-chlorine bonded derivatives of the amino acid tyrosine when the effluents were treated with heavy doses of chlorine.
Date: July 1977
Creator: Burleson, Jimmie L.
System: The UNT Digital Library
Simultaneous Part-Per-Billion Determination of Sodium and Chloride Ions (open access)

Simultaneous Part-Per-Billion Determination of Sodium and Chloride Ions

The method utilizes both cation and anion concentrator columns in parallel as a preconcentration system. The preconcentrator system is loaded using a reagent delivery module operated for a specific time at a preset flow rate. Total injection volumes of 2-5 ml are routinely used. Various chromatograms are discussed along with detailed information concerning detection limits for sodium and chloride, the system operating conditions, and the solutions to other pitfalls which have arisen during the course of this work.
Date: August 1987
Creator: Gan, Din-Chung
System: The UNT Digital Library
Self-diffusion of Pb210 and Cl36 in Molten PbCl2-KCl Mixtures in the Region of the Compound 2PbCl2-KCl (open access)

Self-diffusion of Pb210 and Cl36 in Molten PbCl2-KCl Mixtures in the Region of the Compound 2PbCl2-KCl

The specific goal of the investigation was the measurement, as a function of temperature, of the self-diffusion coefficients of Pb210 and Cl36 in PbCl2-KCl compositions in the region of the first compound, and to calculate from these data the activation energy necessary for the diffusion of these ions.
Date: June 1960
Creator: Tidwell, Troy Haskell
System: The UNT Digital Library

Design and Development of a Paper Spray Air Sampling Device for Use in Clinical, Defense, and Environmental Applications

Environmental monitoring is becoming increasingly important, primarily in urban areas due to the concentrated levels of human activities. The air sampling device presented is a novel method to sample air which harnesses the power of paper spray ionization paired with the intrinsic advantages of mass spectrometry such as high sensitivity, high selectivity, high throughput, and the ability to monitor multiple compounds at once.
Date: December 2023
Creator: Murillo, Wilbert Alberto
System: The UNT Digital Library