No description available.

No description available.

This paper will analyze the usefulness of depreciation expense to investors. Depreciation expense is a broad allocation accounting practice that treats different types of assets the same. I argue that there are two types of industries: those with wasting assets, and those with real property. The first type experiences true deprecation and deterioration while the second type of asset does not. A simplified model using the earnings response coefficient will measure the relationship between earnings and returns for these different industries; this measurement is a way to quantify usefulness of accounting information. I hypothesize that investors of companies with high wasting assets will find depreciation more useful than those invested in companies with more real property. However, the results were not consistent with my hypothesis – depreciation did not matter more to investors of the industry with high wasting assets. The data set only included two distinct industries, which limited the sample size considerably, and might explain the results. Alternatively, the two groups of assets could be defined more broadly to include more industries for future research.

L'influence des facteurs principe environnement dans le but d'optimiser la production des bioprocédés lipopeptide ont été testés en vue de son utilisation dans la conception nouvelle de bioréacteur à lit fluidisé inverse couplée à une section film de liquide dessus. La production de surfactine lipopeptides et fengycine a été réalisée par les cellules libres et immobilisées aérobie d'un nouveau dérivé spontanée Bacillus subtilis BBG21, qui est un mutant spontané de l'ATCC 21332 considérés comme de type sauvage. Les résultats ont été comparés à ceux obtenus avec la souche de type sauvage. Les principaux paramètres ont été testés: le taux de transfert d'oxygène, le pH et la température. Les souches ont été cultivées dans un milieu de Landy et Landy modifié de tampon MOPS avec 0,1 M. Influence du taux de transfert d'oxygène a été testé dans des flacons agités à l'aide de tailles de flacon différentes, le volume de remplissage, la fréquence d'agitation et de diamètre en secouant, la production de surfactine a montré une forte corrélation avec l'augmentation des taux de transfert d'oxygène, contrairement à la fengycine, tandis que le taux de transfert d'oxygène très diminué dû à l'acidification du milieu de culture grâce à l'absence de production de lipopeptides a été détecté. Trois régimes différents d’optimisation de la production de lipopeptides ont été observées avec un taux élevé, modéré et limité (OTR) et différents (Rsurf / feng). La meilleure productivité a été obtenue pour la culture à pH 7,0 initial. L'augmentation de la température a permis d'améliorer le rendement surfactine mais a réduit la production fengycine qui a été presque indétectable. Toutefois, l'optimisation de la production et le transfert d'oxygène de gaz-liquide et de mousse ont été étudiés dans un laboratoire dans le bioréacteur à lit inverse fluidisé de conception proposée avec une section film liquide dessus. L'oxygène coefficient de transfert volumétrique (kla) et l'activité mousse ont été déterminés à différentes conditions en utilisant le modèle et la fermentation réelle. Les niveaux de surfactant ont été examinés ci-dessous, et plus près de la concentration micellaire critique (CMC). Les valeurs des (kla) avec deux types de particules de différentes rugosité de surface ont été déterminées et pour une gamme de vitesses de liquide superficielle (Ul) de 0,01 à 0,05 m s-1, les vitesses des gaz (Ug) de 0,003 à 0,014 m s-1 et la surface tensions (σ) de 30 à 72 mN m-1. L'influence du support a été démontrée. Une forte réduction de ce paramètre a été observée dans le modèle et le réel et le media modèle quand la tension de surface a diminué de 72 à 30 mN m-1. Toutefois, la présence de surfactine et fengycine génère un moussage excessif qui impose des difficultés sur le rendement du bioréacteur qui était contrôlée par la conception proposée de nouveaux réacteurs. Les différentes gammes de vitesse spatiale du gaz minute, ainsi que l'état de non équilibre de régimes d'écoulements de fluides ont été étudiés. En utilisant l'approche de l'analyse de corrélation pour une dimension (kla) proposée et les coefficients calculés et expérimentaux sont en assez bon accord. / The influences of principle environmental factors in the goal to optimize the lipopeptide production bioprocess were tested in view of its use in new design of inverse fluidized bed bioreactor coupled with a liquid film top section. The production of lipopeptides surfactin and fengycin was performed by free and immobilized aerobic cells of a new spontaneous derivative Bacillus subtilis BBG21, which is a spontaneous mutant of the ATCC 21332 considered as wild type. Results were compared to those obtained with the wild-type strain. The main parameters were tested: oxygen transfer rate, pH and temperature. The strains were cultivated in Landy and Landy modified medium buffered with MOPS 0.1 M. Influence of oxygen transfer rate was tested in shake flasks by using different flask size, filling volume, shaking frequency and shaking diameter, the surfactin production showed high correlation with the increasing of oxygen transfer rate, contrary with fengycin, while the highly decreased of the oxygen transfer rate due to acidification of the culture medium due to no production of lipopeptides was detected. Three different lipopeptides production optimization regimes were observed with high, moderate and limited (OTR) and different (Rsurf/feng) ratio. The best productivity was obtained for the culture at initial pH 7.0. Interestingly the increasing of temperature allowed to improve the surfactin yield but reduced the fengycin production which was nearly undetectable. However, the production optimization and the gas-liquid oxygen transfer and foaming were studied in a laboratory scale in the proposed bioreactor design inverse fluidized bed with a liquid film top section. The volumetric oxygen transfer coefficient (kla) and foaming activity were determined at various conditions using model and real fermentation. Surfactant levels were examined below, near and over the critical micelle concentration (CMC). The (kla) values with two types of different surface roughness particles were determined and for a range of superficial liquid velocities (Ul) from 0.01 to 0.05 m s-1, gas velocities (Ug) from 0.003 to 0.014 m s-1 and surface tensions (σ) from 30 to 72 mN m-1. The influence of support has been demonstrated. A strong reduction of this parameter has been observed in the real and model media when the surface tension decreased from 72 to 30 mN m-1. However, the presence of surfactin and fengycin generates extensive foaming that imposes difficulties on the bioreactor performance which was controlled by the proposed new reactor design. The different ranges of gas minute space velocity, as well as no steady state regimes of fluid flows have been studied. By using the dimensionless analysis approach a correlation for (kla) has been proposed and the calculated and experimental coefficients are in fairly good agreement.

Les particules en suspension dans l'eau de mer incluent les sédiments, le phytoplancton, le zooplancton, les bactéries, les virus et des détritus. Ces particules sont communément appelés matière en suspension (MES). Dans les eaux côtières, la MES peut parcourir de longues distances et être transportée verticalement à travers la colonne d'eau sous l'effet des vents et des marées favorisant les processus d'advection et de resuspension. Ceci implique une large variabilité spatio-temporelle de MES et quasiment impossible à reconstituer à travers les mesures traditionnelles des concentrations de MES [MES], par filtration de l'eau de mer à bord de bateaux. La [MES] peut être obtenue à partir de capteurs optiques enregistrant la diffusion et déployés soit de manière in-situ, soit à partir d'un satellite dans l'espace. Depuis la fin des années 70, par exemple, les satellites "couleur de l'eau" permettent d'établir des cartes de [MES] globales. La fréquence d'une image par jour pour la mer di Nord de ces capteurs polaires représente un obstacle non négligeable pour l'étude de variabilité de la [MES] dans les eaux côtières où la marée et les vents engendrent des variations rapides au cours de la journée. Cette limitation est d'autant plus importante pour les régions avec une couverture nuageuse fréquente. Les méthodes in-situ à partir d'un navire autonome ou d'une plateforme amarrée permettent d'enregistrer des données en continu mais leur couverture spatiale reste néanmoins limitée. Ce travail a pour objectif de mettre en avant les techniques de mesures in-situ et satellite de la [MES] en se concentrant principalement sur deux points. Premièrement, d'acquérir une meilleure connaissance de la variabilité de la relation entre la [MES] et la lumière diffuse, et deuxièmement, d'établir des cartes de [MES] dans la mer du Nord avec le capteur géostationnaire météorologique Européen (SEVIRI) qui donne des images chaque 15 minutes.La variabilité de la relation entre la [MES] et la lumière diffuse est étudiée à l'aide d'une banque de données in-situ. Nous démontrons que la [MES] est le mieux estimée à partir des mesures dans l'intervalle rouge du spectre de lumière rétro-diffuse. Par ailleurs, la relation entre la [MES] et la rétrodiffusion est gouvernée par la composition organique/inorganique des particules, ce qui représente des possibilités d'amélioration pour les algorithmes d'estimation de [MES] à partir de la couleur de l'eau. Nous démontrons aussi qu'avec SEVIRI il est possible d'estimer la [MES], la turbidité et le coefficient d'atténuation, deux variables étroitement liées à la [MES], avec généralement une bonne précision. Bien qu'il y ait d'importantes incertitudes dans les eaux claires, cette réussite est remarquable pour un capteur météorologique initialement conçu pour le suivi des nuages et des masses glaciaires, cibles beaucoup plus brillantes que la mer! Ce travail démontre pour la première fois que la variabilité de la [MES] à l'échelle temporelle des marées dans les eaux côtières au sud de la mer du Nord peut être capturée et mesurée par le biais de la télédétection de la couleur de l'eau ; ce qui ouvre des opportunités pour le monitoring de la turbidité et pour la modélisation des écosystèmes. Le premier capteur géostationnaire couleur de l'eau a été lancé en juin 2012, donnant des images multispectrale des eaux coréennes chaque heure. D'autres capteurs vont probablement suivre dans l'avenir, couvrant le reste des eaux du globe. Ce travail nous permet donc de préparer, de façon optimale, l'arrivée de ces capteurs qui vont révolutionner l'océanographie optique. / Particles suspended in seawater include sediments, phytoplankton, zooplankton, bacteria, viruses, and detritus, and are collectively referred to as suspended particulate matter, SPM. In coastal waters, SPM is transported over long distances and in the water column by biological, tide or wind-driven advection and resuspension processes, thus varying strongly in time and space. These strong dynamics challenge the traditional measurement of the concentration of SPM, [SPM], through filtration of seawater sampled from ships. Estimation of [SPM] from sensors recording optical scattering allows to cover larger temporal or spatial scales. So called ocean colour satelittes, for example, have been used for the mapping of [SPM] on a global scale since the late 1970s. These polar-orbiting satellites typically provide one image per day forthe North Sea area. However, the sampling frequency of these satellites is a serious limitation in coastal waters where [SPM] changes rapidly during the day due to tides and winds.Optical instruments installed on moored platforms or on under-water vehicles can be operated continuously, but their spatial coverage is limited. This work aims to advance in situ and space-based optical techniques for [SPM] retrieval by investigating the natural variability in the relationship between [SPM] and light scattering by particles and by investigating whether the European geostationary meteorological SEVIRI sensor, which provides imagery every 15 minutes, can be used for the mapping of [SPM] in the southern North Sea. Based on an extensive in situ dataset, we show that [SPM] is best estimated from red light scattered in the back directions (backscattering). Moreover, the relationship between [SPM]] and particulate backscattering is driven by the organic/inorganic composition of suspended particles, offering opportunities to improve [SPM] retrieval algorithms. We also show that SEVIRI successfully retrieves [SPM] and related parameters such as turbidity and the vertical light attenuation coefficient in turbid waters. Even though uncertainties are considerable in clear waters, this is a remarkable result for a meteorological sensor designed to monitor clouds and ice, much brighter targets than the sea! On cloud free days, tidal variability of [SPM] can now be resolved by remote sensing for the first time, offering new opportunities for monitoring of turbidity and ecosystem modelling. In June 2010 the first geostationary ocean colour sensor was launched into space which provides hourly multispectral imagery of Korean waters. Other geostationary ocean colour sensors are likely to become operational in the (near?) future over the rest of the world's sea. This work allows us to maximally prepare for the coming of geostationary ocean colour satellites, which are expected to revolutionize optical oceanography. / De in zeewater aanwezige zwevende materie zoals sedimenten, fytoplankton, zooplankton, bacteriën, virussen en detritus, worden collectief "suspended particulate matter" (SPM) genoemd. In kustwateren worden deze deeltjes over lange afstanden en in de waterkolom getransporteerd door biologische processen of wind- of getijdenwerking, waardoor SPM sterk varieert in ruimte en tijd. Door deze sterke dynamiek wordt de traditionele bemonstering van de concentratie van SPM, [SPM], door middel van filtratie van zeewaterstalen aan boord van schepen ontoereikend. Optische technieken die gebruik maken van de lichtverstriioongseigenschappen van SPM bieden een gebieds- of tijdsdekkend alternatief. Zogenaamde "ocean colour" satellieten bijvoorbeeld leveren beelden van o.a. [SPM] aan het zeeoppervlak op globale schaal sinds eind 1970, met een frequantie van één beeld per dag voor de Noordzee. Deze frequentie is echter onvoldoende in onze kustwateren waar [SPM] drastisch kan veranderen in enkele uren tijd. Optische instrumenten aan boord vann schepen of op onderwatervoertuigen kunnen continu meten, maar de gebiedsdekking is deperkt. Dit werk heeft tot doel de lichtverstriioongseigenschappen van SPM te karakterizeren en te onderzoeken of de Europese geostationaire weersatelliet, die elk kwartier een beeld geeft, kan worden gebruikt voor de kartering van [SPM] in de zuidelijke Noordzee. Op basis van een grote dataset van in situ metingen tonen wij aan dat [SPM] het nauwkeurigst kan worden bepaald door de meting van de verstrooiing van rood licht in achterwaartse richtingen (terugverstrooiing). Bovendien blijkt de relatie tussen [SPM] en terugverstrooiing afhankelijk van de organische-anorganische samenstelling van zwenvende stof, wat mogelijkhenden biedt tot het verfijnen van teledetectiealgoritmen voor [SPM]. Voorts tonen woj aan dat de Europese weersatelliet, SEVIRI, successvol kan worden aangewend voor de kartering van [SPM] en gerelateerde parameters zoals troebelheid en lichtdemping in de waterkolom. Hoewel met grote meetonzekerheid in klaar water toch een opmerkelijk resultaat voor een sensor die ontworpen werd voor detectie van wolken en ijs! Op wolkenvrije dagen wordt hierdoor de getijdendynamiek van [SPM] in de zuidelijke Noordzee voor het eerst detecteerbaar vanuit de ruimte, wat nieuwe mogelijkheden biedt voor de monitoring van waterkwaliteit en verbetering van ecosysteellodellen. Sinds juni 2010 is de eerste geostationaire ocean colour satelliet een feit : elk uur een multispectraal beeld van Koreaanse wateren. Vermoedelijk zullen er in de (nabije?) toekomst meer volgen over Europa en Amerika. Dit werk laat toe ons maximaal voor te bereiden op te komst van zo'n satellieten, waarvan verwacht wordt dat zij een nieuwe revolutie in optische oceanografie zullen ontketenen.

Gas quench technology has been rapidly developed recently with the intent to replace water and oil quench for medium and high hardenability steel. One of the significant advantages is to reduce the distortion and stress, compared to water and oil quench. However, not like liquid quench, no gas quench steel hardenability test standard exists. The fundamental difference between liquid quench and gas quench is heat transfer coefficient. The workpiece with the same hardness after liquid and gas quench process may have different microstructure due to different cooling curves. The concept of equivalent gas quench heat transfer coefficient (HTC) is proposed to have the same cooling curve, microstructure and hardness when compared with liquid quench. Several influencing factors on steel hardenability have been discussed, such as austenizing temperature, heating rate, holding time, composition variation and grain size difference. The phase quantification by X-ray Diffraction and Rietveld Refinement method is developed to measure phase percentage for steel microstructure, including martensite, ferrite and carbides. The limitations and improvements of modified Jominy gas quench test are discussed. The fundamental limitation of Jominy gas quench test is that one gas quench condition cannot be used for both low hardenability steel and high hardenability steel at the same time. The same steel grade would have different hardenability curves under different gas quench conditions, which made it difficult to compare the hardenability among different steels. The critical HTC test based on Grossmann test is proposed to overcome the limitations. In the test, different gas quench HTC conditions are applied to the sample with the same geometry. After sectioning each bar at mid-length, the bar that has 50% martensite at its center is selected, and the applied gas quench HTC of this bar is designated as the critical HTC. This test has many advantages to take the place of modified Jominy gas quench test. Since one of the advantages of gas quench is greater process flexibility to vary cooling rates, gas marquenching technology is proposed to obtain martensite with less sever cooling rate and reduce the distortion and stress.

This research explored the relationship between an earlier-year technical course and one later year technical course, for students who graduated between 2010 and 2015 with the degree of bachelor of engineering. The research only focuses on the courses in the program of Electrical Engineering at the University of Victoria. Three approaches based on the two major factors, coefficient and enrolment, were established to select the course grade predictor including Max(Pearson Coefficient), Max(Enrolment), and Max(Pi) which is a combination of the two factors. The prediction algorithm used is linear regression and the prediction results were evaluated by Mean Absolute Error and prediction precision. The results show that the predictions of most course pairs could not be reliably used for the student performance in one course based on another one. However, the fourth-year courses are specialization-related and have relatively small enrolments in general, some of the course pairs with fourth-year CourseYs and having acceptable MAE and prediction precision could be used as early references and advices for the students to select the specialization direction while they are in their first or second academic year. / Graduate

An average heat transfer coefficient, h_bar, is often used to solve heat transfer problems. It should be understood that this is an approximation and may provide inaccurate results, especially when the temperature field is of interest. The proper method to solve heat transfer problems is with a conjugate approach. However, there seems to be a lack of clear explanations of conjugate heat transfer in literature. The objective of this work is to provide a clear explanation of conjugate heat transfer and to determine the discrepancy in the temperature field when the interface boundary condition is approximated using h_bar compared to a local, or variable, heat transfer coefficient, h(x). Simple one-dimensional problems are presented and solved analytically using both h(x) and h_bar. Due to the one-dimensional assumption, h(x) appears in the governing equation for which the common methods to solve the differential equations with an average coefficient are no longer valid. Two methods, the integral equation and generalized Bessel methods are presented to handle the variable coefficient. The generalized Bessel method has previously only been used with homogeneous governing equations. This work extends the use of the generalized Bessel method to non-homogeneous problems by developing a relation for the Wronskian of the general solution to the generalized Bessel equation. The solution methods are applied to three problems: an external flow past a flat plate, a conjugate interface between two solids and a conjugate interface between a fluid and a solid. The main parameter that is varied is a combination of the Biot number and a geometric aspect ratio, A_1^2 = Bi*L^2/d_1^2. The Biot number is assumed small since the problems are one-dimensional and thus variation in A_1^2 is mostly due to a change in the aspect ratio. A large A_1^2 represents a long and thin solid whereas a small A_1^2 represents a short and thick solid. It is found that a larger A_1^2 leads to less problem conjugation. This means that use of h_bar has a lesser effect on the temperature field for a long and thin solid. Also, use of ¯ over h(x) tends to generally under predict the solid temperature. In addition is was found that A_2^2, the A^2 value for the second subdomain, tends to have more effect on the shape of the temperature profile of solid 1 and A_1^2 has a greater effect on the magnitude of the difference in temperature profiles between the use of h(x) and h_bar. In general increasing the A^2 values reduced conjugation.

No description available.

SuperCritical-Water-cooled Reactors (SCWRs) are being developed as one of the Generation-IV nuclear-reactor concepts. Main objectives of the development are to increase thermal efficiency of a Nuclear Power Plant (NPP) and to decrease capital and operational costs. The first objective can be achieved by introducing nuclear steam reheat inside a reactor and utilizing regenerative feedwater heaters. The second objective can be achieved by designing a steam cycle that closely matches that of the mature supercritical fossil-fuelled power plants. The feasibility of these objectives is discussed. As a part of this discussion, heat-transfer calculations have been performed and analyzed for SuperCritical-Water (SCW) and SuperHeated-Steam (SHS) channels of the proposed reactor concept. In the calculations a uniform and three non-uniform Axial Heat Flux Profiles (AHFPs) were considered for six different fuels (UO2, ThO2, MOX, UC2, UC, and UN) and at average and maximum channel power. Bulk-fluid, sheath, and fuel centerline temperatures as well as the Heat Transfer Coefficient (HTC) profiles were obtained along the fuel-channel length. The HTC values are within a range of 4.7 – 20 kW/m2⋅K and 9.7 – 10 kW/m2⋅K for the SCW and SHS channels respectively. The main conclusion is that while all the mentioned fuels may be used for the SHS channel, only UC2, UC, or UN are suitable for a SCW channel, because their fuel centerline temperatures are at least 1000°C below melting point, while that of UO2, ThO2, and MOX may reach melting point. / UOIT