Energiflöden i fläkt och fläktkoppling har undersökts för att öka förståelsen om hur fläktvarvtalet varierar med fordonshastigheten. Problemet har studerats på en lastbil vid olika fordonshastigheter och fläktvarvtal. Undersökningen har genomförts genom att studera olika förluster, geometri på fläktblad, data från tidigare prover och genom CFD-simulering. De förlusterna som undersökts är lagerförluster och viskoförluster. Utifrån den befintliga geometrin på fläkten och från simulering har inloppshastigheterna mot fläkten jämförts. Simuleringarna är gjorda på en befintlig provbil där fläkten är simulerad med hjälp av MRF-modellering. Studien visar att fläktkopplingsmodell, fläkttyp och fläktens diameter inte är av så stor betydelse för att förklara problemet, däremot kan det ses att bilens modul är av vikt. Detta tros vara av vikt på grund av vad modulen får för tryckuppbyggnad. Luftens hastighet in mot fläkten kan vara en parameter som är av betydelse utifrån analys av tidigare provning och från simulering. Utifrån det kan det funderas på om fläkten bör dimensioneras om, att den bör dimensioneras efter låga fläktvarvtal istället för höga. Detta på grund av att fläkten endast är aktiv, och då har höga varvtal, cirka X % av bilens drifttid för typisk långtradartrafik, det vill säga inte så lång tid av bilens drifttid. Resultatet från den här undersökningen bör ses som en vägvisare hur man ska gå vidare för att förklara problemet och om man utifrån det kan minska bränsleförbrukningen. / Energy flows in fan and fan-clutch has been investigated to increase the understanding of how fan speed varies with the vehicle speed. The problem has been studied on a truck at different vehicle speeds and fan speeds. The thesis has been conducted by studying various losses, the fan geometry, data from previous tests and by CFD-simulation. The losses noted are bearing losses and visco losses. Based on the existing fan geometry and from simulation, the inlet velocities against the fan has been compared. The simulation are made from an existing test vehicle where the fan is simulated using MRF modeling. The study shows that the model of the fan clutch, the fan type and fan diameter are not so important to explain the problem, however, it can be seen that the truck’s module is of importance. This is thought to be important because of the modules pressure build-up. It can also be seen that the air velocity towards the fan can be a parameter that is important based on analysis of previous testing and from simulation. However, on this basis we should be reconsidering if the fan should be dimensioned the way it is today, at high fan speeds, or if it should be dimensioned at low fan speeds. This because the fan is only active, and then has high speeds, about X % of the car’s operating time for a typical long haulage truck, i.e. not that long of the truck’s operating time. The result of this study should be interpreted as a guide on how to proceed to explain the problem and if it can be used to reduce the fuel consumption.

This thesis is written in the publishable paper format, which is comprised of two papers. The research took a case study approach analyzing the Twitter activity of the Ottawa Senators of the National Hockey League, and their followers’. The first paper, using content analysis, analyzed the Senators’ tweets and resulting follower activity level. Focus group research aimed to uncover what specific Senators’ Twitter activity influenced their followers online, and their creation and perceived inclusion in an online fan group. The second paper, through the questionnaire method, looked at the Senators’ Twitter and it’s the influence on their follower’s social identity formation and fan commitment levels. These two papers highlight the importance of sport organizations facilitating connections between their followers and most importantly, facilitating the creation of an online central fan group specific to their Twitter handle.

This thesis deals with the development and design of a mechanism used to change the geometry of impeller blades in radial fans. Firstly, a suitable design was selected and then constructed taking into account the forces and loads applied. The blade consists of two parts - fixed, and movable. The movable part extends or retracts behind the fixed part of the blade, changing its length and therefore the operating characteristics of the fan. The simulation part of the work deals with the effect of the changed blade geometry on the fan performance at one particular operating point. The results show a slight reduction in performance, but on the other hand the fan is operable under a wider range of operating conditions. The conclusion of the paper suggests the need for further research to gain a deeper understanding of the capabilities of radial control mechanism fans.

Although sorghum malt is relatively rich in free amino nitrogen (FAN), the 150 mg FAN/L threshold recommended for brewing is difficult to obtain. The vitreous nature of the sorghum endosperm hinders proteolysis during brewing. Hence, exogenous proteolytic enzymes are often required to increase hydrolysis of sorghum malt protein to produce sufficient FAN in order to support rapid yeast growth during fermentation. Ten exogenous proteases were examined for their production of FAN in sorghum malt mashing. Mashing was done at 550C for 45 minutes. Levels of FAN, as determined by the ninhydrin method, showed great variation among the proteolytic enzymes, ranging from 96 in control to 182 mg/100 g malt with possibly of most effective proteolytic enzyme. The variation in FAN level was possibly due to different optimal mashing conditions of exogenous proteases used and perhaps due to low ratios of exopeptidase/endopeptidase in the enzyme preparations. Low temperature (400C) and long duration mashing for (7 hours) gave good FAN production during mashing to a total of 113 and 138 mg/100 g malt in control and the treatment with exogenous proteolytic enzyme Flavourzyme plus malt, respectively. The exogenous enzyme (Flavourzyme) plus potassium metabisulphite (PMB) increased FAN production during mashing in the ratio of 2 to 1 in a treatment where PMB was added compared to one without. Similarly, hot wort extract (HWE) increased by 8% during mashing with exogenous enzyme plus PMB compared to one without PMB, respectively. PMB was involved in destabilizing the disulphide bonds in the sorghum protein polypeptide chains allowing proteolytic enzymes better accessibility to proteins. The increase in HWE was possibly due to the starch being freed from the sorghum protein matrix. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed some oligomeric and polymeric kafirins after mashing. With transmission electron microcopy (TEM), protein bodies of varying sizes with partially degraded peripheral edges and some holes were seen after mashing. SDS-PAGE and TEM results suggest insufficient proteolysis. High protein digestibility sorghum’s potential for brewing was examined with reference to FAN production. Although during mashing FAN increased by approx. 82 and 115% for unmalted normal and high digestibility sorghums, respectively, the 150 mg FAN/L threshold, recommended for brewing was not achieved. FAN production to levels above 150 mg/L may only be realized if normal sorghum malt or high protein digestibility sorghum malt is mashed with exogenous enzymes containing sufficient exopeptidases coupled with appropriate mashing conditions. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Food Science / unrestricted

Economical and environmental factors together with energy policies towards more efficient systemsare the driving force for the development of the vehicle industry. Significant changes have beenmade to fulfill new emissions legislation but the basic internal combustion vehicle architecture hasbeen kept. New emission treatment systems that increase the thermal loading of the cooling systemhad been added within the same package envelope as before, which means less space to place coolingfans and a greater need for airflow. Changes in the cooling system, namely the replacement of thehydraulic fan drive system by electrical fans is one of the energy efficient alternatives for severalcity buses under certain environments, like the ”typical red city buses”, well-known in the UnitedKingdom. In this thesis study, hydraulic fans are compared with electrical fans and a road-mapof the benefits and drawbacks of the two systems is developed, based on real traffic performanceperformance data and the results of existing simulations and tests. In addition, new simulations arepresented in order to find the most efficient design for the cooling system as well as a comparisonof these results with previous ones. This road map will be used later by Volvo-Buses Group as atool to better understand in which circumstances electrical fans can be beneficial, in terms of fuelconsumption, noise production, cooling performance, control of the fans and associated costs.

Sports organisations must continuously assess how better to meet or exceed consumer expectations and perceptions of their experience in order to maintain and increase the number of spectators and loyal fans attending their sporting events. This study aims to enhance our understanding of which characteristics of a service attribute will best define its quality and impact on spectator behaviour by understanding the causal relationship between perceived service quality (PSQ) and satisfaction.

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The purpose of this research study was to provide a rich and thick description of what it means to be a NASCAR (National Association of Stock Car Racing) fan. Specifically, the researcher examined how NASCAR fans create their sport fan identity, how being a NASCAR fan influences their overall identity, and the social and cultural aspects associated with being a NASCAR fan. The participants consisted of 12 (10 male & 2 female) self-identified NASCAR fans in attendance at one of three races (Daytona 500 at Daytona International Speedway in Daytona Beach, FL; Samsung/RadioShack 500 at Texas Motor Speedway in Justin, TX; or the Richmond 400 at the Richmond International Raceway (RIR) in Richmond, VA) during the 2006 NASCAR Nextel Cup Series season. Interviews were transcribed verbatim and analyzed, yielding four major themes. The themes that emerged included: (a) entry into NASCAR, (b) being A NASCAR Fan, (c) "ya'll NASCAR fans": fan camaraderie, and (d) win on Sunday...sell on Monday. In general, the participants expressed that their entrance into the sport of NASCAR had been facilitated by close friends and family. Whether they grew up going to the racetrack with their family or were persuaded by a close friend to attend a race, the experience of attending a NASCAR Sprint Cup event propelled them on a lifelong journey following the sport. All of the participants articulated their affinity for fellow NASCAR fans and spending time with other fans at the track, serving as a way of enhancing their sport fan identity. The NASCAR fans in this study also expressed that the amount of sponsorship within the sport was something that they viewed as having an impact on their behavior as a consumer, with many having noted they try to exclusively purchase NASCAR sponsor brands. Recommendations for researchers based on the interviews are also discussed. / Kinesiology

An advanced model of active control of fan noise for ultra high bypass turbofan engines has been developed. This model is based on a boundary integral equation method and simulates the propagation, radiation and control of the noise generated by an engine fan surrounded by a duct of finite length and cylindrical shape, placed in a uniform flow. Control sources, modeled by point monopoles placed along the wall of the engine inlet or outlet duct, inject anti-noise into the duct to destructively interfere with the sound field generated by the fan. The duct inner wall can be lined or rigid. Unlike current methods, reflection from the duct openings is taken into account, as well as the presence of the evanescent modes. Forward, as well as backward (i.e., from the rear of the engine), external radiation is computed. The development of analytical expressions for the sound field resulting from both the fan loading noise and the control sources is presented. Two fan models are described. The first model uses spinning line sources with radially distributed strength to model the loading force that the fan blades exert on the medium. The second model uses radial arrays of spinning point dipoles to simulate the generation of fan modes of specific modal amplitudes. It is shown that these fan models can provide a reasonable approximation of actual engine fan noise in the instance when the modal amplitude of the propagating modes or the loading force distribution on the fan blades, is known. Sample cases of active noise control are performed to demonstrate the feasibility of the model. The results from these tests indicate that this model 1) is conducive to more realistic studies of active control of fan noise on ultra high bypass turbofan engines because it accounts for the presence of evanescent modes and for interference between inlet and outlet radiation, which were shown to have some impact on the performance of the active control system; 2) is very useful because it allows monitoring of any region of the acoustic field; 3) is computationally fast, and therefore suitable to conduct parametric studies. Finally, the potential that active noise control techniques have for reducing fan noise on an ultra high bypass turbofan engine is investigated. Feedforward control algorithms are simulated. Pure active control techniques, as well as hybrid (active/passive) control techniques, are studied. It is demonstrated that active noise control has the potential to reduce substantially, and over a relatively large far field sector, the fan noise radiated by an ultra high bypass turbofan engine. It is also shown that a hybrid control system can achieve significantly better levels of noise reduction than a pure passive or pure active control system, and that its optimum solution is more robust than the one achieved with a pure active control system. The model has shown to realistically predict engine acoustic behavior and is thus likely to be a very useful tool for designing active noise control systems for ultra high bypass turbofan engines. / Ph. D.