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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

Effects of beta-carotene and alpha-tocopherol on stability of soybean oil

Kramer, Jacqueline Bauer. January 1986 (has links)
Call number: LD2668 .T4 1986 K72 / Master of Science / Human Nutrition
2

Analysis of trace metals in palm oil

Fung, Ying-sing, 馮應昇 January 1977 (has links)
published_or_final_version / Chemistry / Master / Master of Philosophy
3

Characterization and azeotropic distillation of crude wood oil

Cranford, Richard John, 1960- January 1989 (has links)
The batch distillation of crude wood oil by direct liquefaction was studied; azeotropic distillations and some characterization were also performed. It was found that 26-33 percent of the crude wood oil could be distilled by simple batch vacuum distillations with pressures from 50-300 mm Hg. With the use of ethylene glycol and glycerol 29-85 percent more oil was distilled partly due to the azeotrope formed which allows the oil to boil at a reduced pressure. The water liberated and the polymerization which took place during the distillations were studied. It was found that fluid catalytic cracking bottoms eliminates polymerization when it is co-distilled with the crude wood oil. A novel scheme for the separation of the phenolic fraction by azeotropic distillation is presented.
4

Oil analysis in machine diagnostics

Vähäoja, P. (Pekka) 30 May 2006 (has links)
Abstract This study concentrates on developing and tuning various oil analysis methods to meet the requirements of modern industry and environmental analytics. Oil analysis methods form a vital part of techniques used to monitor the condition of machines and may help to improve the overall equipment effectiveness value of a factory in a significant manner. Worm gears are used in various production machines, and their breakdowns may cause significant production losses. Wearing of these gears is relatively difficult to monitor with vibration analysis. Analysis of two indicator metals, copper and iron, may reveal wearing phenomena of worm gears effectively, and savings can be significant. Effective wear metal analysis requires good tools. ICP-OES with kerosene dilution is widely used in wear metal analysis, but purchasing and using of ICP-OES is expensive. A cheaper FAAS technique with similar pre-treatment of oil samples was tested and it proved to be useful especially in analyzing small amounts of samples. The accuracy of FAAS was sufficient for quantitative work in machine diagnostics and waste oil characterization. Solid debris analyses are useful in oil contamination control as well as in detection of wearing mechanisms. Membrane filtration, optical microscopy, SEM and automatic particle counting were applied in analysis of rolling and gear oils. Particle counting is an effective way to detect oil contamination, but in the studied cases even larger particles than those detected in normal ISO classes would be informative. However, membrane filtration and optical microscopy may reveal the wearing machine element exactly. Additives provide oils with desired properties thus they should be monitored intensively. A FTIR method for quantitative analysis of fatty alcohols and fatty acid esters in machinery oils was developed during this work. It has already been used successfully in quantitative and qualitative analysis of machinery oil samples. Various kinds of oils may be spilled into the soil during use and in accident situations, and they can migrate to groundwater layers. Biodegradation of oils can remove them from the soil or water completely or at least diminish the amount of harmful substances. An automatic, respirometric BOD OxiTop method was used to evaluate the biodegradability of various oils in water and soil media. The biodegradation of certain bio and mineral hydraulic oils was evaluated in groundwater, where bio oils usually biodegraded more effectively than mineral oils. The use of oils in machines weakened especially the biodegradability of bio oils. Biodegradability of bio oils was also studied in standard conditions of OECD 301 F and bio oils usually biodegraded moderately good in these conditions. The biodegradation of forestry chain oils and wood preservative oils was evaluated in forest soils. Linseed oil biodegraded moderately, but certain experimental wood preservatives biodegraded more effectively. Widely used creosote oil biodegraded in a lesser degree. Rapeseed oil-based chain oils biodegraded more effectively than corresponding tall oil.
5

Wear Debris Detection and Oil Analysis Using Ultrasonic and Capacitance Measurements

Appleby, Matthew Paul 25 August 2010 (has links)
No description available.
6

Condition Monitoring (CM) : Concept selection of sensors for monitoring of mechanical wear / Tillståndsövervakning (CM) : Konceptframtagning av sensorer för övervakning av mekaniskt slitage

Vinblad, Hampus January 2022 (has links)
This bachelor thesis has been executed with the product development process double diamond. The thesis has been performed at Karlstad University in cooperation with Kongsberg Maritime in Sweden AB. The objective of the thesis has been to develop a condition monitoring system for Kongsberg’s waterjet department. Substantially it has to do with finding a system which could monitor wear and problematic trends  in  the hydraulic oil and oil lubricated bearings. The wear is to be translated to an electrical signal which could be used to alert and visualize the wear to the end user. The literature study was divided into two parts. The first part of the literature study consisted of analyzing and understanding wear and condition monitoring systems. The second part of the literature study instead consisted of analyzing different kind of measurement methods which could be suitable for so-called online measurements. The used references come from scientific articles and documents publicized by various classification societies. The final solution consists of a system of different sensors and measurement methods. Due to the fact that the system is to be  installed on ships, the system needed to be considered with rules from various classification societies. The rules which are relevant for the project was placed in an elimination matrix where concepts that didn’t live up to the rules were scrapped. Further on, the sub concepts were evaluated  and selected  with a relative matrix and a weighted Kesselring matrix, which gave the most suitable sub concepts. The sub concepts were merged into a complete condition monitoring system at concept level. The final system solution could measure solid particles in oil, humidity in oil, oil flow, torque, rotational speed of the shaft and vibrations. The selected sensors also enabled the system to measure shaft power, oil conductivity and oil permittivity which were not included in the task.
7

Análise da contaminação e degradação do óleo lubrificante e desgaste de um motor Ottolizado alimentado por biogás / Analysis of contamination and degradation of the lubricating oil and wear a adapted Otto engine powered by biogas

Bertinatto, Rovian 14 February 2014 (has links)
Made available in DSpace on 2017-07-10T15:14:30Z (GMT). No. of bitstreams: 1 DissertacaoRovianBertinatto.pdf: 1926860 bytes, checksum: c7c01fd0d065212573f2db62e9ff5a6f (MD5) Previous issue date: 2014-02-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The implementation of digesters for waste material treatment in rural properties, as well as the use of the biogas that is generated on the making of mechanical energy, has increased and alongside with it the necessity of understanding the influence of this fuel in internal combustion engines. This study aims to analyze the filtered biogas influence on contaminating and degrading the lubricating oil and the engine. Lubricating oil samples were collected on every 75 hours of engine operation, and, after they had been correlated among themselves and with new oil samples, it was possible to determine the elements that contaminate and degrade the engine after hours of engine working. Therefore, it was possible to notice that the hydrogen sulphide influences the lubricating oil and engine performance. Among the metals it was possible to identify that the copper concentration exceeded the maximum recommended levels, and the elevation of its concentration was related to the elevation of lead and tin, mainly after 375 Hm. As for the additives, the magnesium variation levels affected the lubricant perfomance. By monitoring the quality of the lubricant is possible to increase the oil change interval in 50%, which results in a 33.3% save regardomg the lubricant cost every worked hour / A crescente implantação de biodigestores para tratamento de resíduos nas propriedades rurais, e a utilização do biogás gerado na produção de energia mecânica, trouxe a necessidade de se conhecer a influência da utilização deste combustível nos motores de combustão interna. Este trabalho teve como objetivo analisar a influência da utilização do biogás filtrado na contaminação e degradação do óleo lubrificante, desgaste e corrosão do motor. Amostras de óleo lubrificante foram coletadas a cada 75 horas de funcionamento do motor, e após correlacionadas dentre elas e com a amostra de óleo novo, determinando os elementos presentes no biogás que contribuem para a contaminação e degradação do óleo lubrificante, como também o desempenho do lubrificante no decorrer das horas trabalhadas e o desgaste do motor. Os resultados demostram que o gás sulfídrico influencia no desempenho do óleo lubrificante e no desgaste do motor. Dentre os metais foi identificado que a concentração de cobre excedeu o máximo recomendado pela literatura, e a elevação da sua concentração teve relação com a elevação de chumbo e estanho, principalmente após as 375 hM. Em relação aos aditivos, foi a variação das concentrações de magnésio que impactou no desempenho do lubrificante. Através do monitoramento da qualidade do lubrificante é possível estender o intervalo de troca de óleo do motor do presente estudo em 50%, resultando em uma economia de 33,3% no custo do lubrificante por hora trabalhada.
8

AN EFFECT-DRIVEN FRACTIONATION APPROACH FOR THE ISOLATION AND CHARACTERIZATION OF CYP1A INDUCING COMPONENTS OF CRUDE OILS

Saravanabhavan, Gurusankar 26 November 2007 (has links)
Exposure to crude oils has been shown to induce CYP1A enzymes and cause chronically toxic effects in aquatic organisms. Earlier studies indicated that polycyclic aromatic hydrocarbons (PAHs) present in crude oil are primarily responsible for the chronic toxicity. Crude oil contains a variety of PAHs; the majority of them are alkyl substituted. In this work, we have used an effects-driven fractionation and analysis approach (EDFA) to isolate and characterize PAHs present in Alaskan North Slope and Scotian Light crude oils that are toxic to fish. The crude oil components were first fractionated into four fractions using a low temperature vacuum distillation technique. Among them, the heavy gas oil fraction (boiling range 287°C – 461°C) of both oils caused highest toxicity to fish. To isolate the PAHs from waxes present in this fraction, a low temperature wax precipitation method was developed and optimized. CYP1A induction results showed that the extract contained a large number of CYP1A inducers while the residue contained none. Chemical analyses confirmed that most of the PAHs were partitioned into the extract fraction. Alkyl PAHs present in the extract were further fractionated into five fractions based on the number of aromatic rings using a normal phase HPLC method. Chemical analysis and the toxicity testing of these fractions indicated that alkyl PAHs belonging to classes such as phenanthrene, fluorene, naphthobenzothiophene, and chrysene are likely responsible for the observed toxic effects. To aid the EDFA scheme, a new HPLC-DAD method for the analysis of alkyl PAHs was developed. The alkyl PAHs were first fractionated based on the number of aromatic rings using a normal phase column followed by their analysis using reverse phase HPLC–DAD technique. The reverse phase analysis involved classifying the alkyl PAH peaks into different PAH classes based on their DAD spectra. Then, alkyl carbon numbers for each peak were assigned based on their retention time. To analyze co-eluting alkyl PAH isomers an offline multi-dimensional HPLC method was developed. Orthogonal separation was achieved by first fractionating the alkyl PAHs on a normal phase column followed by the RP-HPLC-DAD analysis. Using these data a 2D contour plot was developed and used for the detailed analysis of alkyl PAHs isomers. Analysis results showed good agreement with a gas-chromatography-mass-spectrometric (GC-MS) analysis method, and the new method was able to distinguish some PAH types which could not be identified by GC-MS. / Thesis (Ph.D, Chemistry) -- Queen's University, 2007-11-19 13:46:18.602
9

Study of Oil Degradation in Extended Idle Operation Heavy Duty Vehicles

Kader, Michael Kirk 02 October 2013 (has links)
Advances in engine oil technology and increased combustion efficiency has resulted in the longer oil intervals in vehicles. Current oil change interval practice only takes into account the mileage a vehicle has driven and does not consider other vehicle operations that affect oil life like extended idle. Routine oil sampling is one way to ensure optimal oil intervals, but the price continuous analysis can be prohibitive. It is possible to use on board diagnostic (OBD) data to correlate oil degradation to engine usage in order to develop an algorithm that is applicable to many vehicles. While much research has been conducted for light duty vehicles, little has been completed for heavy duty vehicles, in particular vehicles that idle a majority of their time. This study uses multiple heavy duty vehicles that are monitored by monthly routine oil analysis and logging of on board diagnostic data to determine the effects extended idle has on the wear rate of oil. The vehicles were used in their normal operation; this resulted in an average idle run time of 60% of run time and no less than 50% in a single vehicle. At each sample the quality of the oil and the operation of the engines were assessed. The results of the oil analysis showed very little degradation of oil. As expected, a negative correlation was seen in viscosity and total base number (TBN) but not abnormal when compared to base oil. Significant degradation was not seen even after using the vehicle passed the manufacturer recommended oil intervals. Analysis of engine operation showed that the temperature of the oil was optimal for 85% of idle operation. In addition, oil pressures at idle were sufficiently higher than the minimum pressure recommended by the manufacturer, but was less than half of the average in use oil pressure. The combination of low pressure and optimal temperature has resulted in little oil degradation. The results from the study have shown that extended idling in the study vehicles can be treated similar to long trip interval service for oil degradation. Additionally, extended idling did not result in abnormal engine wear or excessive contamination.
10

Monitoramento e avaliação da condição de um sistema propulsor aeronaútico através de técnicas de análise de partículas em óleos lubrificantes

Santos Junior, José Farias dos [UNESP] 03 August 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-03Bitstream added on 2014-06-13T19:58:09Z : No. of bitstreams: 1 santosjr_jf_me_guara.pdf: 1211785 bytes, checksum: c98805cec7f1bd9e53920e8e6cf06c59 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O procedimento de análise de óleos e graxas vem sendo implementado em diferentes setores, tais como indústria de papel e celulose, usina de álcool, empresas marítimas e empresas aéreas comerciais. As técnicas de análise de óleos lubrificantes permitem o aumento da vida útil de equipamentos, a economia de custos de manutenção. Na área militar esta abordagem é usual desde a década de quarenta. No entanto os países desenvolvidos que vêm participando de grande conflitos bélicos têm explorado muito este recurso com o objetivo de minimizar os custos operacionais e aperfeiçoar o cumprimento de missões. Assim, esta tecnologia envolvida é estratégica, cabendo aos países em desenvolvimento a implementação de programas mais eficazes de forma a ter maior grau de independência, aumento da disponibilidade e confiabilidade de equipamentos de modo a economizar recursos. A proposta da pesquisa em desenvolvimento é complementar o programa de manutenção baseado em análise de óleos e graxas no sentido de explorar e aplicar o potencial destas técnicas, visando as atividades de dificuldades em serviço (problemas operacionais) e investigação de incidentes/acidentes aeronaúticos. O estudo de viabilidade deste tipo de programa poderá gerar um programa de Garantia da Qualidade que permita detectar os modos de falha nos sistemas das aeronaves de defesa. Por todas as considerações acima mencionadas, um programa de análise de óleo é imperativo numa empresa aérea comercial ou mesmo numa Força Aérea de Defesa. As possíveis desvantagens na implementação de um programa de análise de óleo são o seu custo ( logística, recursos humanos, instalações, equipamentos, etc) e o tempo que o citado programa leva para ser consolidado. / The procedure of oil and grease analysis has been implemented in different sectors, such as industry of paper and cellulose, maritime, alcohol plants, companies and commercial airlines. The techniques of lubricate oil analysis allow the increase of the useful equipment life, the economy in maintenance costs. In the military field this boarding are usual since the decade of forty, however the developed countries that has been participated in World War II have explored much of this resource with the objective to minimize the operational costs and to optimize the missions fulfillment. Thus this involved technology is strategic, fitting to the developing countries the implementation of more efficient programs of form to have greater degree of independence, increase of the availability an equipment reliability in order to save resources. The proposal of the research carried on is to complement the program of maintenance based on oil and grease analysis and greases in order explore and to apply the potential of these techniques, aiming at to the activities of difficulties in service (operational problems) an inquiry of aeronautical incidents/accidents. The feasibility study this type of program will be able to generate a program of Quality Assurance that allows detecting the failure modes in the systems of the defense aircraft. For all considerations mentioned above, a program of oil analysis is imperative in a commercial airline or even in an Air Force of Defense. The possible disadvantages to the implementation of oil analysis program are the their cost (logistic, human resources, physical place, equipments and so on) and the time to consolidate such kind of program.

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