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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

Glucosinolates in Brassica and their role in mediating pest and pathogen interactions

Giamoustaris, Athanasios January 1995 (has links)
No description available.
2

Combustion and emission characteristics of biofuels in diesel engines

Labecki, Lukasz January 2010 (has links)
This study was concerned with the performance of biofuels in diesel engines. Generally, the basic combustion and emission characteristics of Rapeseed Oil (RSO) and Soya Oil (SO) result in a lower in-cylinder pressure peak than diesel. This led to the reduction of Nitrogen Oxides (NOx) emissions and to relatively high soot emissions. Further measurements of RSO were done in order to investigate the influence of injection pressure, injection timing and Exhaust Gas Recirculation (EGR) on combustion and emission characteristics. A high soot emission from RSO was reduced by increased injection pressure. Moreover, injection timing also had to be varied in order to reduce the soot emissions from RSO. The retarded injection timing (3 deg bTDC) and increased injection pressure (1200 bar) for the blend of 30% RSO resulted in a reduction of soot emission to the same level as from diesel fuel. Further investigation regarding the soot emissions was done for Rapeseed Methyl Ester (RME) under turbocharged engine operation. The application of the boost pressure resulted in stable engine operation at a late injection timing of 5 deg aTDC. A simultaneous reduction of soot and NOx emissions has been achieved for RME at an injection timing of TDC and high EGR percentage (40 – 50 %). The soot particles size distribution under different engine operating conditions for RME and diesel has also been investigated. Moreover, the characteristic of Electrostatic Mobility Spectrometer (EMS) and the design of primary dilution system have been provided in order to understand the influence of the dilution process and to obtain more real results. Generally, RME showed less particles concentration in the nucleation mode when compared to diesel. Moreover, high EGR caused a shift of the particles from the nucleation mode by agglomeration into the accumulation mode for both fuels. The effect of injection pressure could only be seen in the accumulation mode, where high injection pressure slightly reduced the concentration number. The soot emission was effectively reduced by the usage of the diesel particulate filter (DPF). For this purpose, the soot particles size distributions before and after the DPF have been measured at different engine speeds and loads. At low engine torque, the soot was effectively filtered while the operation under high engine loads resulted in low soot particle concentration especially in the nucleation mode, after the DPF.
3

Antioksidantų likopeno ir santokvino įtaka vištų dedeklių produktyvumui bei kiaušinių kokybei, naudojant jų lesaluose rapsų aliejų / Antioxydants Lycopene and Santoquin influence for laying hens and quality of eggs productivity, using rapeseed oil in the feeds

Hoppenienė, Jelena 19 May 2014 (has links)
Šiais laikais nemažas dėmesys atkreipiamas į paukščių laikymo sąlygas ir jų lesalų kokybę. Siekiant pagerinti vištų imunines savybes, jų produktyvumą bei produkto rodiklius, kasmet atliekami tyrimai, įterpiant į lesalus įvairius priedus. Todėl mano darbo tikslas ištirti antioksidantų likopeno ir santokvino įtaką dėsliųjų vištų produktyvumui ir kiaušinių kokybei, naudojant jų lesaluose rapsų aliejų. Siekiant darbo tikslo įgyvendinimo iškelti šie uždaviniai: 1. Nustatyti antioksidantų likopeno ir santokvino įtaką vištų dedeklių dėslumui, lesalų sąnaudoms ir išsaugojimui, naudojant jų lesaluose rapsų aliejų. 2. Nustatyti antioksidantų likopeno ir santokvino įtaką kiaušinių kokybiniams parametrams, naudojant jų lesaluose rapsų aliejų. 3. Nustatyti antioksidantų likopeno ir santokvino įtaką jusliniams kiaušinių rodikliams, naudojant jų lesaluose rapsų aliejų. Išvados: 1. Vištų kūno masė atitiko linijų derinio Lohmann Brown auginimo rekomendacijas. 2. Antioksidantų likopeno ir santokvino įtakoje vidutinis kiaušinių svoris per visą bandymo laikotarpį tik II tiriamojoje grupėje buvo 3 proc., didesnis, lyginant su kontroline grupe (p>0,05). 3. Per visą laikotarpį tiek I tiriamojoje tiek ir II tiriamojoje grupėse kiaušinių skaičius buvo 10 ir 6 proc., o dėjimo intensyvumas buvo 11 ir 4 proc. mažesnis, lyginant su kontroline grupe (p>0,05). 4. Lesalų sąnaudos 1 kg kiaušinių masės gauti buvo 1 proc. didesnės, o santokvino priedas 2 proc. sumažino lesalų sąnaudas, palyginus su... [toliau žr. visą tekstą] / The objective of the work: to analyse antioxydant lycopene and santoquin influence for laying hens and quality of eggs productivity, using rapeseed oil in the feed. The tasks of work:1. To set antioxydants Lycopene and Santoquin influence for laying hens and quality of eggs productivity, using rapeseed oil in the feed. 2. To set antioxydants Lycopene and Santoquin influence for egg qualitative parameters, using rapeseed oil in the feed. 3. To set and to analyse antioxydants Lycopene and Santoquin influence for sensoring egg parameters, using rapeseed oil in the feed. Methods of the work: research. The test were made by approved methodology. Feeding test was performed on thirty 30 weeks old Lohman Brown cross laying hens, which were divided into 3 groups. Each group consists of 10 hens. Lohman Brown laying hens were feeded with bulky compuonds feeds with addition of rapeseed oil (control group). Laying hens of a group I were fed feeds containing 4 percentage rapeseed oil + lycopene (0.5 g / kg), and group II - 4.5 percentage rapeseed oil + santoquin (0.15 g / kg). During the test laying hens were held in individual cages with stationary trough feeders and waterers on equal feeding and keeping conditions. Laying hens were fed with compounds feeds of 125 g per day. The results of research: According to the influence of antioxidants lycopene and santoquin, to compare with control group, the average of egg weight during the test period was higher in II group of 3 percentage (p> 0... [to full text]
4

Degradation of polycyclic aromatic hydrocarbons by actinomycetes /

Pizzul, Leticia, January 2006 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.
5

Biodiesel production by using heterogeneous catalyst / Tillverkning av biodiesel med heterogena katalysatorer

Khurshid, Samir Najem Aldeen January 2014 (has links)
No description available.
6

Investigation of Probiotic Organogel Formulations for use in Oral Health

Sonesson, Elin January 2013 (has links)
The aim of the project is to investigate how a more viscous, gel like formulation can be made of BioGaia´s Prodentis Drops, which is a probiotic product for oral use. The two different strains of Lactobacillus reuteri that are used in the product, together called L. reuteri Prodentis, have been clinically proven to be effective in treatment of gingivitis and caries formation. The existing product is a highly liquid oil suspension that has been described as too runny and difficult to get into tooth pockets and between teeth. Therefore a gel formulation would be preferred. Pre-trials were excecuted to see what combinations and quantities of ingredients could work. Three different formulations using 3 %, 5 % and 7 % beeswax as thickening agent proceeded to another round of trials, as well as one formulation where the original oil was exchanged for hydrogenated rapeseed oil. In the beeswax formulations fumed silicon dioxide was being used as well. Three different analyses were executed, considering bacterial survival, viscosity and phase separation of gels. The bacterial survival proved to be acceptable in all samples even after 14 days of incubation in 37oC. The formulation with 7 % beeswax was the most viscous one, followed by 5 % beeswax, 3 % beeswax and the formulation with hydrogenated oil, respectively. Phase separation could be seen in the hydrogenated oil formulation already after seven days and even more so after 14 days. There were also signs of separation in the formulation with 3 % beeswax after 14 days. It was concluded that in further development of the Prodentis Drops it is recommendable to proceed with the 5 % beeswax formulation.
7

Cetano skaičių didinančio priedo įtaka rapsų aliejumi veikiančio dyzelinio variklio darbo ir deginių emisijos rodikliams / The effect of the cetane number improving additive on the performance and emission of the exhaust of diesel engine operating on rapeseed oil

Tarvainis, Vytautas 16 June 2014 (has links)
Aleksandro Stulginskio Universitete, Transporto ir Jėgos Mašinų Inžinerijos Institute, atliktais tyrimais nustatyta, kad vieno cilindro tiesioginio įpurškimo dyzelinis variklis (,,Oruva“ F1L511) maitinamas pagerintu, 0,08; 0,12; 0,20vol% cetaninį skaičių (CS) didinančiu priedu, rapsų aliejumi (RA), gali efektyviai veikti ir išskirti mažesnę, kai kurių emisijos komponentų dalį. Dyzelinio variklio išvystytas didžiausias efektyvusis slėgis siekė 0,57MPa, varikliui veikiant 2000 min-1 sūkių dažniu. Variklio minimaliosios lyginamosios efektyviosios degalų sąnaudos sumažėjo nuo 272g/kWh iki 268g/kWh tai yra 1,5% panaudojus 0,12vol% cetaninį skaičių didinantį priedą rapsų aliejuje. Deginių dūmingumas sumažėjo 45% vidutinės (pe=0,4MPa) ir 40% didžiausios (pe=0,57MPa) apkrovos srityje atitinkamai panaudojus 0,12vol% ir 0,20vol% cetaninį skaičių didinantį priedą rapsų aliejuje. Bandymų metu didžiausias ƞe=0,364 variklio efektyvusis naudingumo koeficientas buvo pasiektas variklį maitinant 0,12vol% cetaninį skaičių didinančiu priedu apdorotu rapsų aliejumi ir jam išvysčius 5,3 kW efektyviąją galią. Tačiau mažesnės ir didesnės variklio išvystomos efektyviosios galios srityse aukštesnis variklio efektyvusis naudingumas buvo bazinio rapsų aliejaus naudojimo atveju. / Studies conducted at Aleksandas Stulginskis University (ASU) of Transport and Power Machinery Engineering Institute showed that a single-cylinder, air-cooled, direct-injection diesel engine (" Oruva " F1L511 ) can be with rapeseed oil treated with 0.08vol%, 0.12vol% and 0.20vol% the cetane number (CN) improving agent. Diesel engine developed the maximum effective pressure of 0.57MPa when running at 2000 rpm speed. Using of 0.12vol% of the cetane number improving agent (2-ethylheksyl-nitrate) to rapeseed oil the brake specific fuel consumption reduced in the range 272 g/kWh to 268 g/kWh, i.e. 1.5% when running at moderate (pe=0.38MPa) load and 2000 rpm speed. As a result of 0.12vol% the smoke opacity decreased by 45% at moderate (pe=0.4MPa) and 40% at maximum (pe=0.57MPa) load. During the tests, the highest ƞe=0.364 effective efficiency engine was when running on rapeseed oil treated with 0.12vol% cetane improving agent developed at the power output of 5.3 kW.
8

Lipid peroxidation <i>in vivo</i> : Evaluation and application of methods for measurement

Södergren, Eva January 2000 (has links)
<p>Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement <i>in vivo</i> has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation <i>in vivo</i> that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation.</p><p>The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples.</p><p>A methodology for measurement of the total amount (sum of free and esterified) of an F<sub>2</sub>-isoprostane, 8-iso-prostaglandin F<sub>2α</sub>, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F<sub>2α</sub> in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride.</p><p>Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F<sub>2α</sub> and a major prostaglandin F<sub>2α</sub> metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation.</p><p>In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F<sub>2α</sub>, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet.</p><p>In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation <i>in vivo</i> under basal conditions and in the pathology of diseases.</p>
9

Lipid peroxidation in vivo : Evaluation and application of methods for measurement

Södergren, Eva January 2000 (has links)
Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement in vivo has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation in vivo that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation. The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples. A methodology for measurement of the total amount (sum of free and esterified) of an F2-isoprostane, 8-iso-prostaglandin F2α, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F2α in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride. Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F2α and a major prostaglandin F2α metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation. In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F2α, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet. In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation in vivo under basal conditions and in the pathology of diseases.
10

Purification des eaux polluées par du phénol dans un pertracteur à disques tournants / Purification of water polluted with phenol in a rotating discs pertractor

Ehtash, Moamer 11 July 2011 (has links)
Ce travail se situe dans le cadre des recherches du laboratoire sur un procédé d’extraction et desextraction, qui implique trois phases liquides, deux phases aqueuses et une phase organique. La faisabilité d’un tel procédé passe par le choix de la phase organique et par l’étude des équilibres mis en jeu lors du processus d’extraction.Le principal objectif concerne : la récupération et la concentration de phénol contenu dans une solution aqueuse, en utilisant un pertracteur à disques tournants alternatifs en régime batch, semi-batch et continu. Par un mécanisme du transfert de matière entre les phases, le phénol passe de la phase aqueuse d’alimentation vers la phase organique puis de la phase organique vers la phase aqueuse réceptrice.La faisabilité de la méthode est testée en mode fermé. Nous étudions l’influence de certains paramètres : tels que la concentration du phénol, la variation de pH de la phase d’alimentation, la vitesse de rotation des disques et le volume de la phase organique, sur l’évolution du transfert du phénol entre les phases. Une solution aqueuse à pH 2, ayant une concentration en phénol égale à 50, 100 ou 300 mg.L-1, est mise en contact avec de l’huile de colza, qui est elle-même en contact avec une solution aqueuse à pH 13. Les résultats montrent qu’au bout de six heures de fonctionnement, 70% à 99% du phénol contenu initialement dans la solution aqueuse à pH 2, se trouve dans la phase aqueuse à pH 13.Afin de récupérer et de concentrer le phénol dans la phase réceptrice, nous avons réalisé des expériences dans le pertracteur fonctionnant en mode semi-ouvert et en mode ouvert.En système semi-ouvert, l’influence de trois paramètres est étudiée : la concentration initiale de phénol, la vitesse de rotation des disques et le débit de la phase d’alimentation. En système ouvert, seul l’influence du débit à la phase aqueuse est analysée. Enfin, grâce à la modélisation basée sur la théorie du double film, nous avons estimé l’ordre de grandeur des coefficients de transferts de matière partiels pour différentes vitesses de rotation en système fermé. / This work is focused on a pertraction process, coupling extraction and stripping steps in the same apparatus and involving three liquid phases, two aqueous phases and one organic phase. The process feasibility requires the choice of a appropriate organic phase (membrane) and a phase equilibria studies.The main objective was recovery and concentration of phenol contained in dilute aqueous solutions using a rotating discs pertractor in batch, semi-batch and continuous mode. The phenol is transferred from the feed phase (aqueous phase) through the membrane (organic phase) in the receiving phase (aqueous phase).The feasibility of the method is tested in a batch system. We studied the influence of some parameters such as the phenol concentration, the feed pH, the discs rotational speed and the volume of the organic phase. An aqueous solution at pH 2 (feed) with a phenol concentration equal to 50, 100 and 300 mg.L-1, is placed in contact with rapeseed oil (liquid membrane), that is itself in contact with an aqueous solution at pH 13 (receiving phase). The obtained results show that after 6 hours, 70% to 99% of phenol initially contained in the aqueous solution at pH 2, is transferred in the aqueous phase at pH 13.To concentrate phenol in the receiving phase, we performed experiments in semi-batch and continuous mode.In semi-batch system, the influence of three parameters is studied: the feed concentration, the discs rotation speed and the feed flowrate. In open system, (continuous mode), only the influence of the aqueous phases flowrates is analyzed.Finally, using mass transfer model based on a double film theory, we estimate the partial mass transfer coefficients for three phases at different rotation speeds in batch system.

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