In many occupations such as welding, workers are exposed to a combination of several hazards. One of these is the exposure to fumes, particularly those produced from welding processes involving electrical arcs. The inhalation of welding fume can cause both temporary side effects and longer term health complications. These health effects lower the productivity and quality of life of the welder which in turn costs the employer through reduced worker productivity and potential compensation. Current techniques of fume measurement determine bulk quantity of formation without regard to fume plume dissipation into the work place. While some research has been conducted into dissipation, measurements near the welding arc have proven difficult and either numerical or salt water modelling have been used. Such modelling aims to replicate the welding process but is ultimately detached from the actual welding variables involved and does not provide data on fume concentration. Since welder exposure is determined by both fume concentration and dissipation into the workplace measurement techniques which could provide both would be considered highly desirable. In the field of combustion research a number of different laser techniques are used to image soot particulates in flames. These techniques include laser scattering, laser extinction and laser induced incandescence. As yet none of these techniques have found application to the measurement or imaging of particulate matter in arc welding fume plumes. In the work presented here these techniques have been investigated for welding fume measurements of concentration and dissipation. Laser scattering was used successfully to image the fume plume close to the welding arc of actual gas metal and flux cored arc welding processes. The resulting images provided relative fume concentration maps that were quantified when combined with measurements from laser extinction. Laser induced incandescence, while successfully applied to the imaging of soot concentration in flames, was found to have limited capabilities when applied to welding fume particulates. Fume box measurements were undertaken for GMAW and FCAW to determine actual FFR in response to changes in welding variables. The results were in general agreement with those obtained from laser techniques and referenced in literature. The fume plume images collected from in-situ laser measurements were compared with those from previous modelling of plume shape, radial spread and virtual origin. Laser diagnostics demonstrated a number of capabilities not available with traditional fume measurements. The findings of this research provide unique insight into fume dissipation. Such findings can be applied to minimise the quantity of fume, the transmission to the breathing zone and ultimately worker exposure in the workplace. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339888 / Thesis (Ph.D.) - University of Adelaide, School of Mechanical Engineering, 2008

Sérios problemas ambientais têm origem em processos de combustão incompletos. Entre os produtos indesejados está a fuligem, considerada como um dos principais fatores da mudança climática observada nos último anos. Desta forma, ferramentas para diagnóstico da emissão de material particulado se fazem necessárias. Com o advento do laser, o desenvolvimento de técnicas óticas não intrusivas teve início. Dentre elas, destaca-se a técnica denominada incandescência induzida por laser (laser induced incandescence – LII), a qual pode gerar resultados resolvidos no espaço para a fração volumétrica de fuligem. Neste contexto, este trabalho apresenta um estudo experimental sobre a produção de fuligem em duas situações: na primeira, foram estudadas chamas laminares pré-misturadas de etileno e ar aplicando-se a técnica LII. Os resultados foram calibrados a partir da fração volumétrica de fuligem média empregando a técnica de extinção de luz, obtendo-se, então, resultados quantitativos espacialmente resolvidos da fração volumétrica de fuligem. A utilização de diferentes gases no escoamento anular também foi avaliada. A segunda situação abordada envolve o estudo de chamas laminares não pré-misturadas utilizando o gás natural como combustível. O impacto da diluição de inertes em diferentes proporções sobre a fração volumétrica de fuligem em diversas alturas da chama foi estudado por meio da técnica LII. Os resultados obtidos foram comparados à outros resultados presentes na literatura e servirão como validação de futuros modelos de formação de fuligem. / Serious environmental problems are assigned to incomplete combustion processes. Among the unwanted products, soot can be related as an important factor of climate changes observed in the last years. Thus, particulate material emissions diagnostic tools are necessary. Due the laser advent, the development of non-intrusive optical techniques was possible. One of the most importante technique is the laser induced incandescence, LII, which can generate spatially and temporally resolved results of soot volume fraction. In this context, an experimental study regarding the soot production was developed in two different situations: in the first one, premixed laminar flames of ethylene and air were investigated by applying the LII technique. The results were calibrated through the average of soot volume fraction results obtained by the light extinction technique. Therefore, it was possible to obtain quantitative results of spatially resolved soot volume fraction. Different gases employment at the annular flow were also evaluated. The second situation studied involves the analysis of natural gas laminar non-premixed flames. The impact of different inert gas dilution ratio on the soot volume fraction at different heights of the flame was evaluated by the LII technique. The results were compared to other authors and will serve as validation for future soot formation models.

Measurements of soot emission properties are of interest in both fundamental research and combustion-based industries. Laser-induced incandescence of soot particles is a novel technique that allows unobtrusive measurements of both soot volume fraction and particulate size with significant advantages. An apparatus utilizing this technique has been customized and used to provide measurements of soot concentration and particle sizing of a laminar, diffusion methane/air flame at pressures of 10, 20 and 40 atm at 6~mm above the burner. Soot volume fraction measurements correlate well with literature findings at all pressures. Despite similar trends, particle size values are found to be consistently larger than values reported in literature. Discussion on the errors of laser-induced incandescence as well as recommendations for improving the apparatus and results are herein.

Measurements of soot emission properties are of interest in both fundamental research and combustion-based industries. Laser-induced incandescence of soot particles is a novel technique that allows unobtrusive measurements of both soot volume fraction and particulate size with significant advantages. An apparatus utilizing this technique has been customized and used to provide measurements of soot concentration and particle sizing of a laminar, diffusion methane/air flame at pressures of 10, 20 and 40 atm at 6~mm above the burner. Soot volume fraction measurements correlate well with literature findings at all pressures. Despite similar trends, particle size values are found to be consistently larger than values reported in literature. Discussion on the errors of laser-induced incandescence as well as recommendations for improving the apparatus and results are herein.

Sérios problemas ambientais têm origem em processos de combustão incompletos. Entre os produtos indesejados está a fuligem, considerada como um dos principais fatores da mudança climática observada nos último anos. Desta forma, ferramentas para diagnóstico da emissão de material particulado se fazem necessárias. Com o advento do laser, o desenvolvimento de técnicas óticas não intrusivas teve início. Dentre elas, destaca-se a técnica denominada incandescência induzida por laser (laser induced incandescence – LII), a qual pode gerar resultados resolvidos no espaço para a fração volumétrica de fuligem. Neste contexto, este trabalho apresenta um estudo experimental sobre a produção de fuligem em duas situações: na primeira, foram estudadas chamas laminares pré-misturadas de etileno e ar aplicando-se a técnica LII. Os resultados foram calibrados a partir da fração volumétrica de fuligem média empregando a técnica de extinção de luz, obtendo-se, então, resultados quantitativos espacialmente resolvidos da fração volumétrica de fuligem. A utilização de diferentes gases no escoamento anular também foi avaliada. A segunda situação abordada envolve o estudo de chamas laminares não pré-misturadas utilizando o gás natural como combustível. O impacto da diluição de inertes em diferentes proporções sobre a fração volumétrica de fuligem em diversas alturas da chama foi estudado por meio da técnica LII. Os resultados obtidos foram comparados à outros resultados presentes na literatura e servirão como validação de futuros modelos de formação de fuligem. / Serious environmental problems are assigned to incomplete combustion processes. Among the unwanted products, soot can be related as an important factor of climate changes observed in the last years. Thus, particulate material emissions diagnostic tools are necessary. Due the laser advent, the development of non-intrusive optical techniques was possible. One of the most importante technique is the laser induced incandescence, LII, which can generate spatially and temporally resolved results of soot volume fraction. In this context, an experimental study regarding the soot production was developed in two different situations: in the first one, premixed laminar flames of ethylene and air were investigated by applying the LII technique. The results were calibrated through the average of soot volume fraction results obtained by the light extinction technique. Therefore, it was possible to obtain quantitative results of spatially resolved soot volume fraction. Different gases employment at the annular flow were also evaluated. The second situation studied involves the analysis of natural gas laminar non-premixed flames. The impact of different inert gas dilution ratio on the soot volume fraction at different heights of the flame was evaluated by the LII technique. The results were compared to other authors and will serve as validation for future soot formation models.

Sérios problemas ambientais têm origem em processos de combustão incompletos. Entre os produtos indesejados está a fuligem, considerada como um dos principais fatores da mudança climática observada nos último anos. Desta forma, ferramentas para diagnóstico da emissão de material particulado se fazem necessárias. Com o advento do laser, o desenvolvimento de técnicas óticas não intrusivas teve início. Dentre elas, destaca-se a técnica denominada incandescência induzida por laser (laser induced incandescence – LII), a qual pode gerar resultados resolvidos no espaço para a fração volumétrica de fuligem. Neste contexto, este trabalho apresenta um estudo experimental sobre a produção de fuligem em duas situações: na primeira, foram estudadas chamas laminares pré-misturadas de etileno e ar aplicando-se a técnica LII. Os resultados foram calibrados a partir da fração volumétrica de fuligem média empregando a técnica de extinção de luz, obtendo-se, então, resultados quantitativos espacialmente resolvidos da fração volumétrica de fuligem. A utilização de diferentes gases no escoamento anular também foi avaliada. A segunda situação abordada envolve o estudo de chamas laminares não pré-misturadas utilizando o gás natural como combustível. O impacto da diluição de inertes em diferentes proporções sobre a fração volumétrica de fuligem em diversas alturas da chama foi estudado por meio da técnica LII. Os resultados obtidos foram comparados à outros resultados presentes na literatura e servirão como validação de futuros modelos de formação de fuligem. / Serious environmental problems are assigned to incomplete combustion processes. Among the unwanted products, soot can be related as an important factor of climate changes observed in the last years. Thus, particulate material emissions diagnostic tools are necessary. Due the laser advent, the development of non-intrusive optical techniques was possible. One of the most importante technique is the laser induced incandescence, LII, which can generate spatially and temporally resolved results of soot volume fraction. In this context, an experimental study regarding the soot production was developed in two different situations: in the first one, premixed laminar flames of ethylene and air were investigated by applying the LII technique. The results were calibrated through the average of soot volume fraction results obtained by the light extinction technique. Therefore, it was possible to obtain quantitative results of spatially resolved soot volume fraction. Different gases employment at the annular flow were also evaluated. The second situation studied involves the analysis of natural gas laminar non-premixed flames. The impact of different inert gas dilution ratio on the soot volume fraction at different heights of the flame was evaluated by the LII technique. The results were compared to other authors and will serve as validation for future soot formation models.

In this doctoral dissertation, two laser-based sensors were evaluated for different applications. Laser Induced Incandescence (LII) is a technique which can provide nonintrusive quantitative measurement of soot and it provides a unique diagnostic tool to characterize engine performance. Since LII is linearly proportional to the soot volume fraction, it can provide in situ, real time measurement of soot volume fraction with high temporal and spatial resolution. LII has the capability to characterize soot formation during combustion. The soot volume fraction from both flames and a soot generator was investigated with LII. The effects of experimental parameters, such as laser fluence, gate delay, gate width and various laser beam focusing, on LII signal was studied. Laser Induced Breakdown Spectroscopy (LIBS), a diagnostic tool for in situ elemental analysis, has been evaluated for on-line, simultaneous, multi-species impurity monitoring in hydrogen. LIBS spectra with different impurity levels of nitrogen, argon, and oxygen were recorded and the intensity of the spectral lines of Ar, O, N, and H observed were used to form calibration plots for impurities in hydrogen measurements. An ungated detection method for LIBS has been developed and applied to equivalence ratio measurements of CH4/air and biofuel/air. LIBS has also been used to quantitatively analyze the composition of a slurry sample. The quenching effect of water in slurry samples causes low LIBS signal quality with poor sensitivity. Univariate and multivariate calibration was performed on LIBS spectra of dried slurry samples for elemental analysis of Mg, Si and Fe. Calibration results show that the dried slurry samples give good correlation between spectral intensity and elemental concentration.

Ce travail porte sur la modélisation de la formation et l'oxydation des suies avec, comme objectif final, l'optimisation du développement des moteurs thermiques en terme de réduction des émissions de particules. Pour atteindre cet objectif, un modèle de suie a été développé et couplé à un modèle de combustion dans un code aérothermique 3D. Le modèle de suie vise à reproduire la distribution en taille des particules avec une précision raisonnable. Pour ce faire, une méthode de sectionnement a été choisie et améliorée afin de satisfaire à des critères industriels en termes de temps de calcul et de charge mémoire. Dans une première étape, un mécanisme cinétique détaillé d'oxydation d'hydrocarbures représentatifs des carburants a été développé et validé dans de larges domaines de pression et de configurations expérimentales. Ce mécanisme permet de modéliser la formation de composés aromatiques dans la phase gaz, étape initiale du modèle de suie. Si l'utilisation d'une cinétique détaillée est indispensable pour satisfaire aux exigences de précision, elle nécessite le recours à des techniques de tabulation de la chimie afin de ne pas recalculer les termes chimiques localement, ce qui est trop coûteux en temps de calcul. Trois types de tables, impliquant des couplages différents avec le modèle de combustion, ont été proposés. L'intégration du modèle de suie dans STAR-CD™ a nécessité l'implantation des tables générées, des équations du modèle de suie et du couplage entre le modèle de suie et le modèle de combustion. Une première validation a été réalisée avec des valeurs de table imposées afin de s'affranchir des hypothèses de couplage. Dans un deuxième temps, la simulation de la combustion dans un moteur conventionnel, à pleine charge, a été réalisée. Les résultats obtenus étant encourageants, une dernière validation a été effectuée sur la base d'une campagne de mesures (technique LII) réalisées sur moteur à accès optiques fonctionnant en charge partielle.

Combustion-generated carbon black nano particles, or soot, have both positive and negative effects depending on the application. From a positive point of view, it is used as a reinforcing agent in tires, black pigment in inks, and surface coatings. From a negative point of view, it affects performance and durability of many combustion systems, it is a major contributor of global warming, and it is linked to respiratory illness and cancer. Laser-Induced Incandescence (LII) was used in this study to measure soot volume fractions in four steady and twenty-eight pulsed ethylene diffusion flames burning at atmospheric pressure. A laminar coflow diffusion burner combined with a very-high-speed solenoid valve and control circuit provided unsteady flows by forcing the fuel flow with frequencies between 10 Hz and 200 Hz. Periodic flame oscillations were captured by two-dimensional phase-locked LII images and broadband luminosity images for eight phases (0°- 360°) covering each period. A comparison between the steady and pulsed flames and the effect of the pulsation frequency on soot volume fraction in the flame region and the post flame region are presented. The most significant effect of pulsing frequency was observed at 10 Hz. At this frequency, the flame with the lowest mean flow rate had 1.77 times enhancement in peak soot volume fraction and 1.2 times enhancement in total soot volume fraction; whereas the flame with the highest mean flow rate had no significant change in the peak soot volume fraction and 1.4 times reduction in the total soot volume fraction. A correlation (ƒv Reˉ1 = a+b· Str) for the total soot volume fraction in the flame region for the unsteady laminar ethylene flames was obtained for the pulsation frequency between 10 Hz and 200 Hz, and the Reynolds number between 37 and 55. The soot primary particle size in steady and unsteady flames was measured using the Time-Resolved Laser-Induced Incandescence (TIRE-LII) and the double-exponential fit method. At maximum frequency (200 Hz), the soot particles were smaller in size by 15% compared to the steady case in the flame with the highest mean flow rate.

王覺一是清末末候一著教的創始者，也是近代一貫道的開山祖師，藉著對其著作<<理數合解>>的研究，可以對清代民間宗教的信仰核心與教義思想略做了解，本研究的撰述方向如下： 第一章緒論說明研究的動機、目的、方法及預期目標。 第二章，王覺一生平其及其教案析探。想要了解一個人的思想，必須先對此人的人生經歷做一番認識。因此本研究將王覺一的生平考述列為本論首章。這一章係借助故宮<<月摺檔>>的資料，對於其教派的成立與發展做合理的推測，以及他如何成為一方之領導者。並且對於光緒九年王氏領導的教派所發生的教案始末，作一較詳細的釐析，並由此一分析中重新檢視王覺一的角色定位。 第三章，王覺一對「理」觀念的承襲與轉化。本章乃追溯王氏思想的啟蒙根源，探討他對於「理」觀念的承襲，並且解析他對「理」的詮釋與所賦予的意義，為下一章的主題作引子。 第四章理天析探本章乃承上一章的敘述觀念，探討王氏理論的核心主旨，撰述理天在他思想體系中的重要性，以及他如何傳承理學思想，轉化思想家思考範疇中「理」的觀念，並且由此而開展的宇宙論與心性論。身為民間宗教的傳道者，如何來看待這些問題，如何由此問題觀攝宇宙的整體與主宰，本章擬由此探討王覺一的理天思維。 第五章，理天在宗教上的意義。如何呈現理天在修道上的意義，才是王覺一思想的關鍵所在。他如何在整體思想中展現人生的終極目的，強調宗教修煉的意義，亦即討論宗教人修道的最後目標與正鵠，尋探回歸人的根源處，本章擬就扣緊宗教意義以探討理天主體的核心。 第六章結論將本論文所作的研究結果，作一綜合性的討論，並敘述王覺一思想對一貫道教義的影響，以及以王覺一做為主題所開演的研究展望，總結王覺一在民間宗教史的價值與意義。