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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The vapor phase association of propionic acid and propionic -[alpha], [alpha] -d₂ acid -d

Child, William Clark, January 1955 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 108-110).
2

Polymerase chain reaction based cloning of acetate kinase in Propionibacterium acidipropionici /

Liao, Yu-Hua, January 2003 (has links)
Thesis (M.S.)--Ohio State University, 2003. / Includes bibliographical references (leaves 59-68).
3

The synthesis of some new retene derivatives from beta-retoylpropionic acid

Cassaday, Sara Anne, January 1940 (has links)
Thesis (Ph. D.)--Columbia University, 1940. / Vita. Bibliography: p. [35].
4

Metabolic engineering for enhanced propionic acid fermentation by Propionibacterium acidipropionici

Suwannakham, Supaporn, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xix, 258 p.; also includes graphics (some col.) Includes bibliographical references (p. 199-212). Available online via OhioLINK's ETD Center
5

Synthetic studies on 2-pyrrolidinones and introduction of the propionic acid group into certain 2-pyrrolidinones /

Byrd, Wendell Mason January 1954 (has links)
No description available.
6

Synthesis, characterization, and potential application of linear bis-MPA

January 2021 (has links)
archives@tulane.edu / There are three major architectural categories of polymeric materials: linear, branched, and dendritic. Each of these architectures have specific advantages that make them suitable for different applications. However, some of these architectures are inaccessible depending on the monomer system employed. In fact, monomers that can be synthesized into all three of these architectures are extremely rare. This is due to several factors including the lack of a monomer branch point or the poor chemoselectivity of the monomer in use. As a result, there are few monomers, such as 3,5-dihydroxybenzoic acid, that can be synthesized into homopolymers of all three categories. Demonstrations of this level of monomer adaptability are few, but with some recent advancements, another monomer, known as 2,2’-bis(hydroxymethyl)propionic acid (bis-MPA), can be added to this short list of versatile monomers. Bis-MPA is a biocompatible monomer that has been used to synthesize linear, branched, and dendritic materials over the last few decades. Its popularity has grown in academic and industrial settings which has led to numerous publications that show the range of applications it can be used for. However, most of these publications use branched and dendritic bis-MPA architectures. These architectures of bis-MPA have existed for some time and have been well studied. Unlike dendritic and branched bis-MPA, linear bis-MPA has only recently been discovered and detailed (last ~20 years) which has led to the publication of several new applications of bis-MPA materials. While linear bis-MPA has been used to synthesize all three architectures, it is important to note that these linear bis-MPA materials all contain a polycarbonate backbone. This is in stark contrast to traditional bis-MPA materials which contain polyester backbones. Though bis-MPA has been used to synthesize polymeric materials of all three architectures, its important to note that the linear bis-MPA materials published thus far are dissimilar to traditional branched and dendritic bis-MPA. To firmly cement bis-MPA as a versatile monomer, much like 3,5-dihydroxybenzoic acid, a linear polyester bis-MPA material would need to be synthesized. Therefore, the goal of this work is to not only develop a synthetic method for producing linear, polyester bis-MPA but use it to better understand the behavior of dendritic bis-MPA materials and explore its potential application. Herein, linear, polyester bis-MPA was synthesized using a brominated bis-MPA monomer derivative followed by a chain-addition polymerization in mildly basic conditions. This polymerization can take place in a range of solvents and unexpectedly occurs through a chain growth mechanism, which will be discussed. Linear, polyester bis-MPA also proved to be a great analog for traditional bis-MPA dendrimers due to their similar atom economy and repeat unit molecular weight. As such, linear and dendritic bis-MPA analogs were compared in a solution size variation investigation along with poly(caprolactone). These analogs were analyzed using size-measuring techniques including gel permeation chromatography (GPC) and diffusion ordered spectroscopy-nuclear magnetic resonance (DOSY-1H NMR). Finally in this work, a potential application for linear, polyester bis-MPA was explored through the use of triazole chemistry via copper catalyzed azide alkyne cycloaddition (CuAAC). The incorporation of triazole moieties into the linear bis-MPA backbone could be of interest due to the antimicrobial properties of the triazole functional groups. Through the discovery of linear, polyester bis-MPA, bis-MPA can not only be cemented as one of a few highly versatile monomers, but this work opens the door for the exploration of a new class of bis-MPA material. / 1 / Oluwapelumi Kareem
7

A kinetic study of the base catalyzed esterification of propionic anhydride with isopropyl and n-propyl alcohols using a high frequency oscillometer

Abraham, Carl Joel 01 January 1961 (has links)
The purpose of this research project is to investigate the base catalyzed reaction of propionic anhydride with n-propyl and isopropyl alcohols using a high frequency (120 megacycles) oscillometer to follow the course of the reaction as it proceeds. The high frequency oscillometer has been used for many types of analytical determinations, and a review of the work up to 1957 is available in a publication by E. H. Sargent Company. The oscillometer has found application in titrations (Hall 1952), analysis of binary systems (Thomas, Faegin, and Wilson 1951) , static ternary systems (West, Robickaus, and Burkhalter 1951) , the study of complexes (Hara 1952 ) , and in the field of chromotography (Baumann and Blaedel 1956; Honda 1953, 1954) . When conductance or dielectric constant changes during the course of a reaction, reaction rates can be studied. Since no electrodes are present, the possibility of electrode contamination, polarization, and an electrical influence on the reaction as it progresses is eliminated. Crystallization velocity and precipitation velocity studies have been made (Asada 1954; Duke, Bever, and Diehl 1949), a saponification reaction has been followed (Jensen, Watson, and Beekham 1951), and rates for the hydrolysis of lower aliphatic esters and esters of chloracetic acid have been measured (Elving 1954; Flom and Elving 1953). The published kinetic -studies using this type instrument have been done in aqueous solution. The principle instrumental effect in these studies is conductometric, whereas the utilization of the binary solution method of analysis in this project is essentially capacitative in its instrumental effect. A study of the base-catalyzed solvolysis of acetic anhydride in methanol -water mixtures has been made (Koskikallis 1959 ) using a method involving consecutive titrations. The rate of this reaction is too fast to be studied using this instrument; however, to date, kinetic studies have been made on the base catalyzed esteriflcation of acetic anhydride with ethyl alcohol (Lowery 1958) and isobutyl alcohol (Lewis 1959) using the high frequency oscillometer.
8

Effects of a propionic acid-based additive on short-term ensiling characteristics of corn and on dairy cows performance

Levital, Tamir. January 2006 (has links)
No description available.
9

Effects of bacterial inoculation and propionic acid on fermentation quality, microbial population, and aerobic stability of ensiled high-moisture ear corn

Sebastian, Sylvester January 1993 (has links)
High-moisture ear corn (HMEC) was untreated, treated with propionic acid (PA) or inoculated with a mixture of Lactobacillus plantarum and Streptococcus faecium, and then ensiled in both tower and laboratory silos. Ensiled HMEC was evaluated for fermentation quality, silage microbiology, and aerobic stability. In control and inoculated ensiled HMEC, maximum pH reduction was observed within 7 d; such pH reduction was observed only after 21 d of ensiling with PA-treated HMEC. Irrespective of treatment, ammonia concentration increased with storage time. The lactic acid content increased up to 42 d of ensilage; between 138 d and 202 d of ensilage, there was a substantial reduction in lactic acid with all treatments. Throughout ensilage, there was no difference in water soluble carbohydrate (WSC) content between control and inoculated HMEC. Secondary fermentation was minimized by both inoculation and PA treatment. Regardless of treatment, the population of lactic acid bacteria increased within 7 d of ensilage and reached a maximum at 21 d of ensilage. Populations of yeasts and moulds decreased with fermentation time up to 42 d, then increased as the ensilage progressed. Bacterial inoculation increased aerobic stability of ensiled HMEC. PA was more effective than inoculation in reducing the disappearance of lactic acid and the rise in pH. Irrespective of treatment, the population of yeasts and moulds and other microorganisms increased in aerated HMEC. Both PA treatment and bacterial inoculation reduced aerobic spoilage of ensiled HMEC. (Abstract shortened by UMI.)
10

Effects of a propionic acid-based additive on short-term ensiling characteristics of corn and on dairy cows performance

Levital, Tamir. January 2006 (has links)
Forage shortage may force producers to feed unfermented or partially fermented forages, which are more susceptible to aerobic deterioration. Propionic acid-based additives can be added to ensiled forages to inhibit yeast and mold growth, and improve the aerobic stability of silages. The objectives of this study were to determine the effects of a propionic acid-based silage additive (Solution Foin) on ensiling characteristics, aerobic stability and feeding value of short-term ensiled corn forage. Chopped whole corn was left untreated or treated with Solution Foin (contains 700 g kg-1 propionic acid and 300 g kg-1 NH4OH). The additive was added to forage prior ensiling at a rate of 5 L ton-1 (wet basis). Treated and untreated forages were placed in six plastic silo bags (three each). Silo bags were opened one day after ensiling and daily samples were collected for 30 consecutive days. Effects on animal performance of feeding treated or untreated forage were determined in a completely randomized design, using 30 lactating cows (178+/-55 days in milk) fed total mixed ration (50:50 forage: concentrate) with the major forage portion consisting of untreated or treated forage. The feeding study started one day post-ensiling. Results showed that Solution Foin reduced (P < 0.05) yeast and mold populations between d 5 and 14 post-ensiling. The highest differences (P < 0.002) were observed on d 10, at which point yeast and mold populations for untreated silage were 7.86 and 2.51 log cfu g-1, respectively. The corresponding values for treated silage were 4.35 and 0.00 log cfu g-1, respectively. Aerobic stability of treated ensiled forage was also improved (P < 0.01) from day 0 (by 159 h) to day 10 (by 33 h) post-ensiling. Solution Foin also increased (P < 0.05) the overall lactic acid and WSC content, and lowered the temperature of the treated ensiled forage in the field. No treatment differences were detected in the forage pH and acetic acid concentration. Dairy cows fed treated forage had similar feed intake (average 23 kg d-1) and milk yield (average 29 kg d-1) to cows fed the untreated forage. It was concluded that Solution Foin can be used to improve the aerobic stability and ensiled forage characteristics of short-term corn forage, likely by reducing yeast and mold populations.

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