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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.
31

Essential oil treatments to control Varroa destructor Anderson and Trueman 2000 (formerly Varroa jacobsoni Oudemans 1904) (Mesostigmata: Varroidae)

Vargas-Sarmiento, María Mercedes, January 2000 (has links)
Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 42-52).
32

Die Rosenkultur und Rosenölindustrie in Bulgarien ...

Sjaroff, Georg, January 1907 (has links)
Inaugural-Dissertation--Universität Leipzig. / Vita.
33

Essential oil yield and composition of rose-scented geranium (Pelargonium sp.) as influenced by harvesting frequency and plant shoot age

Motsa, Nozipho M. January 2006 (has links)
Thesis (M.Sc(Agric.))(Agronomy)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.
34

EFFECTS OF UNCONVENTIONAL PLANT OILS AND RUMEN ADAPTATION ON METHANE GAS EMISSION AND RUMEN FERMENTATION CHARACTERISTICS

Embaby, Mohamed GalalEldeen 01 August 2018 (has links)
The objectives of this work were to investigate the effects of unconventional oils rich in phenolic compounds and rumen adaption on methane (CH4) gas production and rumen fermentation characteristics under in vitro rumen conditions. For this purpose, two sets of trials were conducted. In the first trial, the effects of blackberry, blueberry, raspberry, pomegranate, black seed and hemp oils on CH4 production and fermentation were examined in three 24 h batch culture experiments. Treatments in each experiment consisted of control (no oil supplement), control plus corn oil, or control plus two of the unconventional oils. Oils were added to rumen cultures at 500 mg/L (equivalent to 3.3 g oil/kg of diet dry matter (DM)). After 24 h of incubation, CH4 production was not different between the control and the corn oil treatments. Of the six unconventional oils tested, only hemp and blueberry oils reduced (P<0.05) CH4 production by 9-16% relative to the control and corn oil treatments. No significant differences were observed between treatments in dry matter digestibility (DMD) or total volatile fatty acids (tVFA). Except for a reduction (P<0.05) in acetate concentration with the raspberry oil, and an increase (P<0.05) in valerate concentration with the pomegranate oil, all other treatments had similar VFA concentrations. In the second trial, the effects of adding oregano essential oil (OEO) to adapted and unadapted rumen cultures on CH4 production and rumen fermentation were evaluated under in vitro condition. Rumen cultures were obtained from continues culture fermenters fed a control diet or control diet plus OEO at 250 mg/day for 10 days. The addition of OEO decreased (P<0.05) ii CH4 production only in adapted cultures. Total VFA and acetate concentrations were greater (P<0.05) in the unadapted than adapted cultures and their concentrations decreased (P<0.05) with the addition of OEO particularly when added to the adapted cultures. Propionate concentrations were also greater (P<0.05) in the unadapted than the adapted cultures and concentrations decreased (P<0.05) with the addition of OEO. Dry matter degradability and total gas production decreased (P<0.03) with the addition of OEO in both cultures and total gas production tended (P<0.13) to be lower when added to the adapted cultures. In conclusion, our results showed that hemp and blueberry oils were moderately effective in reducing rumen CH4 formation without compromising rumen fermentation and digestibility. Oregano Essential oil addition negatively affected rumen fermentation in both adapted and unadapted cultures and the effect was greater in the adapted cultures. The greater effects of OEO on CH4 production in the adapted cultures most likely due to the lower fermentation efficiency in these cultures.
35

Seasonal variations of essential oil composition and some biological evaluation of Pelargonium inquinans (L.) Ait. South Africa

Tembeni, Babalwa January 2016 (has links)
Pelargonium inquinans which belongs to the family Geraniaceae, is an essential oil yielding plant. P. inquinans was collected from two different sites in Grahamstown (wild) and Alice, at the University of Fort Hare botanical garden. Authentication of the plant was done by Dr. T. Dold at Schonland herbarium, and the voucher specimen being T01. This study is focused at determining the chemical constituents and biological properties of the essential oils of wild and cultivated P. inquinans across different seasons, as the plant grows throughout the year. Seasonal collection of wild and cultivated P. inquinans was achieved in a duration of 12 months. 32 essential oil samples of P. inquinans were obtained by extraction using hydro-distillation technique for 3-4 hours. The chemical composition of the essential oils was determined using GC/MS and GC/FID. Amongst the 32 essential oils only 4 samples wild ( fresh stem and leaf) and cultivated ( fresh stem and leaf) from summer season were evaluated for analgesic activity using acetic acid induced writhings and hot plate nociception models in mice, anti-inflammatory activity was determined on the egg albumin- induced rat paw oedema in rats. The results obtained from GC-MS revealed a total of 169 components obtained from the leafstem, fresh/dry wild and cultivated P. inquinans. These essential oils showed a great deal of chemotaxonomic variation and similarity in the major and minor components along the season. In spring season the essential oils of wild and cultivated P. inquinans had abundance of hydrogenated sesquiterpenes (20.6percent-66.7percent). The major components were found to be α-caryophyllene (9.1percent-26.8percent), p-xylene (23.3percent-27.5percent), β-caryophyllene (11.4percent-30.9percent), o-xylene (6.3percent-39.4percent), β-thujene (8.7percent), isocaryophyllene (13.9percent), isoborneol (14.2percent), β-myrcene (5.7percent), geranyl acetate (13.8percent), toluene (7.9percent), β-gurjunene (18.5percent), α-cadinene (15.8percent), β-farnesene (14.2percent), 3-carene (12.1percent) and camphene (9.0percent). In summer season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (50.3percent- 63.0percent), oxygenated monoterpenes (30.4percent) and hydrogenated monoterpenes (20.8percent- 61.0percent). The major components were found to be α-caryophyllene (12.3percent-25.8percent), β-caryophyllene (15.1percent- 31.7percent), trans-caryophyllene (10.3percent- 17.8percent), phytol (14.2percent- 20.2percent), camphor (46.5percent), sabinene (27.8percent), elemol (18.1percent), z3-hexenyl isobutyrate (16.3percent), limonene (12.1percent), menthone (12.1percent)< E.E-β-farnesene (14.7percent), palmitic acid (9.6percent), eugenol (9.4percent), cis- β-ocimene (8.7percent), α-terpineol (8.7percent), geranyl acetone (7.8percent), β- humulene (7.5percent). linoleic acid (7.4percent), trans-linalool oxide (7.4percent), β-bisabolene (7.1percent), cis- linalool oxide (7.1percent), ionone (6.9percent), caryophyllene oxide (6.9percent) and germacrene d (6.3percent). In autumn season the essential oils of wild and cultivated P. inquinans were found to be rich in hydrogenated sesquiterpenes (29.3percent- 65.2percent) and oxygenated sesquiterpenes (22.8percent- 31.4percent). The major components were found to be α-caryophyllene (15.5percent- 23.4percent), β-caryophyllene (15.2percent- 17.2percent), β-myrcene (7.7percent-13.8percent), β-humulene (8.7percent- 15.2percent), caryophyllene oxide (9.8- 16.2percent), trans- caryophyllene (16.7percent- 23.3percent), α-humulene (11.8percent- 18.6percent), linoleic acid (11.2percent), palmitic acid (10.4percent), phytol acetate (8.5percent), -longipinene (8.3percent) and citronellol (7.8percent). In winter season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (25.1percent- 48.6percent), oxygenated monoterpenes (47.6percent), oxygenated sesquiterpenes (22.2percent- 28.0percent). The major components were found to be β-caryophyllene (14.6percent- 23.0percent), α-caryophyllene (9.4percent- 18.0percent), trans- caryophyllene (12.2percent- 14.6percent), α-cedrene (26.2percent), germacrene –d-4-ol (16.8percent), 2,6-dihydroxyacetophenone (15.6percent), (+) epibicyclosesquiphellandrene (15.3percent), E-β- farnesene (13.0percent), β-phellandrene (11.7percent), 2-nitrophenol (9.5percent), palatinol (8.4percent), geranyl acetate (7.7percent) and linoleic acid (7.4percent). The oils from the wild and cultivated sources showed significant (p<0.05-0.001) decrease in number of writhes induced by the acetic acid compared to vehicle; caused significant (p<0.05-0.001) delay in reaction time on the hot plate at 60 and 90 min post-treatment and significantly (p<0.05-0.001) reduced oedema size caused by the egg albumin injection compared to the vehicle. The oils from the wild plant showed more potency compared to the cultivated. The essential oils of wild and cultivated P. inquinans showed qualitative, quantitative and chemotaxonomic variation with analgesic and anti-inflammatory activity. These essential oils need to be explored for further biological analysis because of the major components they contain.
36

Potencialização de óleos essenciais como antimicrobianos aplicados em produtos lácteos fermentados /

Feniman, Cristiane Mengue. January 2011 (has links)
Orientador: Ary Fernandes Júnior / Banca: Vera Lúcia Mores Rall / Banca: Carlos Alberto de Magalhães Lopes / Banca: Rubens Monti / Banca: Emani Porto / Resumo: Os óleos essenciais (OEs) apresentam-se como novas opções tecnológicas para serem aplicados como conservantes em alimentos. Entretanto, o uso nas concentrações necessárias para exercerem ação antimicrobiana provoca alterações sensoriais indesejáveis, além de que a essa ação não é desejável quando aplicado em produtos probióticos. O trabalho objetivou identificar e registrar as preferências do público consumidor para alimentos adicionados de OEs, avaliar a ação antimicrobiana do OE de canela em iogurte, adicionado em concentração máxima aceitável sensorialmente (CMAS) e associado com EDTA e/ou polietilenoglicol, verificar a existência de ação antimicrobiana dos OEs de canela, cravo e menta na CMAS contra o Lactobacillus rhamnosus e cultura starter de iogurte durante a vida de prateleira de leite fermentado, determinar a Concentração Inibitória Mínima (CIM) e visualizar os efeitos do OE de canela contra o L. rhamnosus. Os OEs foram obtidos por destilação a vapor e caracterizados quimicamente por cromatografia gasosa e espectrometria de massa. A primeira parte do projeto consistiu em pesquisa de mercado para determinar a melhor associação de OEs com o sabor de frutas no iogurte e os óleos mais associados ao queijo. A máxima concentração aceitável de OE (estipulado na pesquisa de mercado) para o iogurte foi determinada na análise sensorial pela Escala Hedônica de 0 a 9 pontos, com amostras de concentrações crescentes de OE, tendo-se como referencial de aceitação a mediana mínima igual a 7 pontos, referente ao gostei moderadamente. Nessa concentração foi verificada a ação antimicrobiana do OE sozinho e associado com EDTA, polietilenoglicol e ambos, além do tratamento controle. Foram realizadas as contagens de aeróbios mesófilos totais, psicrotróficos e bolores... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Essential oils (EOs) show as new technology options to be used as preservatives in foods. However, the use in necessary concentrations to exert antimicrobial activity causes undesirable sensory changes, and this action is not desirable when applied to probiotic products. The study aimed to identify and record the preferences of the consuming public to foods added with EOs, to evaluate the antimicrobial action of cinnamon EO in yogurt, added to the higher acceptable sensory concentration (HASC) and associated with EDTA and/or polyethylene glycol, to verify the existence of antimicrobial action of cinnamon, clove and mint EOs in the HASC against Lactobacillus rhamnosus and yogurt starter culture during the shelf life of fermented milk, to determine the minimum inhibitory concentration (MIC) and to view the effects of cinnamon EO against L. rhamnosus. The EOs were obtained by steam distillation and chemically characterized by gas chromatography and mass spectrometry. The first part of project involved in market research to determine the best combination of EOs with the taste of fruit in yogurt and oils associated with cheese. The maximum acceptable concentration of EO (stipulated in market research) to the yogurt was determined by sensory analysis scale of 0 to 9 points, with samples of increasing concentrations of OE, haven been as reference the median minimum acceptance equals 7 points, referring to liked moderately. This concentration was found to antimicrobial action of EO alone and associated with EDTA, polyethylene glycol, and both, beyond a control treatment. Counts were performed total mesophilic aerobic, psychrotrophilics, and yeasts and molds. The second part of the project consisted in the survival curve of L. rhamnosus and starter culture in fermented milk, isolated and associated microbial... (Complete abstract click electronic access below) / Doutor
37

Essential oils: their properties, identification and analysis /

Gates, Rupert Granville 01 January 1914 (has links) (PDF)
No description available.
38

Investigation of Material, Process, and Environmental Factors in Bubble Defect Formation for Labels of Bottled Essential Oils

Andrus, Joseph Lloyd 17 June 2022 (has links)
Labeling of consumer products is not only required by regulatory bodies for product identification, but it also serves as a symbol of product quality and prestige. Bubbles under the label are unsightly and impact customer satisfaction. Pressure Sensitive Adhesive (PSA) labels currently make up more than eighty percent of all labels in the market today, yet little research could be found addressing causes of bubbling in an industrial setting. A root cause analysis for bubble development included four aspects: label application, environmental conditions of shipping and storage, defects in glass bottle geometry, and oil contamination. The most significant findings from each area were as follows: Label Application. Force and contact time were confirmed to be significant factors in reducing label bubbling. The equipment settings directly related to these factors should be controlled and monitored. Environmental Conditions. None of the environmental conditions caused growth or appearance of additional bubbles as was the hypothesis. All 4 test conditions had a significant Paired T-test but in the reduction of bubble size. Glass Defects. A random sample of bottles showed very poor capability of the bottle dimensions. However, low capability to produce within specification limits does not necessarily lead to bubbling. A direct comparison test was done to compare diameters and variation from bubbled bottles to non-bubbled. No measurements that could reasonably be related to bubbles caused by glass defectiveness were statistically different. Oil Contamination. Initial data analysis showed that certain oil types had a higher chance of causing bubbling. However, after a controlled experiment was performed, the results were inconclusive that oil contamination pre or post-labeling could cause bubbling in isolation. The experiment did confirm the importance of sufficient pressure in the label application process.
39

IMPROVEMENT OF U.S. EPA MINIMUM RISK ESSENTIAL OILS’ PESTICIDE ACTIVITY THROUGH SURFACTANT ENHANCEMENT AND SYNERGY

Gillilan, Jo Anna 27 August 2012 (has links)
No description available.
40

A Study on the Concentration of Citrus Essential Oils by Adsorption

Kruger, Albert Joseph 01 April 1980 (has links) (PDF)
Deterpenation by concentration of the flavor bearing oxygenated compounds present in Citrus Essential Oils using the column chromatographic method and the parameters affecting the adsorption of these oxygenated compounds at maximum economy versus reasonable efficiency in separation from the non-oxygenated compounds have been studied. Particular attention was given to the maximum number of adsorption-desorption-regeneration cycles that a single column charge could be subjected to before the adsorbent should be replaced. The results of this study suggested the following conditions are of importance with regard to the development of an efficient and economic operation: 1) deactivation of the silica gel column by passage of a raffinate; 2) chilling of the column and feed oil to 5°C; 3) use of minimum silica gel/oil ratio; 4) in-place regeneration of the silica gel. The results of this study also demonstrates that no rearrangements of the non-oxygenated terpenes occurred.

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