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Design, Implementation and Evaluation of a Mobile Exhibition GuideChen, Jingyu Chen January 2007 (has links)
As mobile devices are increasingly merging into our daily lives, exhibition ser- vices are also facing innovation based on the newly available technologies. Our project addresses these new circumstances. We developed a mobile exhibition guide for the exhibition called quot;Mrs Brown's Big Day Out: Hamilton Women in the 1950squot;. That is organized by the Waikato Museum. The proposed sys- tem re-uses the TIP(Tourist Information Provider) system's framework and provides information via mobile devices to visitors on Victoria Street, which is an outdoor part of the exhibition. The information about a sight will be delivered according to visitors' current locations and their interests. We would also like to examine the possibility of re-using our TIP system within the application area of exhibition guide. Therefore, we built the mobile exhibition guide system under the TIP system's framework and developed corresponding services that tailored the system to the requirements of visitors and the exhibition organizer. During the development, we faced a number of challenges, especially, modeling the unknown and unstructured exhibition data into the TIP database. The development process as well as the implementation and evaluation are detailed in this report.
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The Structural Integrity And Damage Tolerance Of Composite T-Joints in Naval VesselsDharmawan, Ferry, ferry.dharmawan@rmit.edu.au January 2008 (has links)
In this thesis, the application of composite materials for marine structures and specifically naval vessels has been explored by investigating its damage criticality. The use of composite materials for Mine Counter Measure Vessels (MCMVs) was desirable, especially for producing material characteristics, such as light weight, corrosion resistance, design flexibility due to its anisotropic nature and most importantly stealth capability. The T-Joint structure, as the primary connection between the hull and bulkhead forms the focus of this research. The aim of the research was to determine the methodology to predict the damage criticality of the T-Joint under a pull-off tensile loading using FE (Finite Element) based fracture mechanics theory. The outcome of the research was that the Finite Element (FE) simulations were used in conjunction with fracture mechanics theory to determine the failure mechanism of the T-Joint in the presence of disbonds in the critical loca tion. It enables certain pre-emptive strengthening mechanisms or other preventive solutions to be made since the T-Joint responses can be predicted precisely. This knowledge contributes to the damage tolerance design methodology for ship structures, particularly in the T-Joint design. The results comparison between the VCCT (Virtual Crack Closure Technique) analysis and the experiment results showed that the VCCT is a dependable analytical method to predict the T-Joint failure mechanisms. It was capable of accurately determining the crack initiation and final fracture load. The maximum difference between the VCCT analysis with the experiment results was approximately 25% for the T-Joint with a horizontal disbond. However, the application of the CTE (Crack Tip Element) method for the T-Joint displayed a huge discrepancy compared with the results (fracture toughness) obtained using the VCCT method, because the current T-Joint structure geometry did not meet the Classical Laminate Plate Theory (CLPT) criteria. The minimum fracture toughness difference for both analytical methods was approximately 50%. However, it also has been tested that when the T-Joint structure geometry satisfied the CLPT criteria, the maximum fracture toughness discrepancy between both analytical methods was only approximately 10%. It was later discovered from the Griffith energy principle that the fracture toughness differences between both analytical methods were due to the material compliance difference as both analytical methods used different T-Joint structures.
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Method development for investigation of real effects on flow around vanesMårtensson, Jonathan January 2010 (has links)
<p>In the development of turbo machinery components it's desirable to not spend more time than necessary when setting up aero-thermal calculations to investigate uncertainties in the design. This report aims to describe general thoughts used in the development of an ICEM-mesh script and the possible configurations in the script file which enables the user to build mesh-grids with/without clearance gap at the hub and/or shroud for different blade geometries. It also aims to illustrate the performance analysis made on the Vinci LH2 turbine, a next generation upper stage engine to the Ariane 5 rocket, in which the effect of the tip gap size on the efficiency has been studied.</p><p>The calculations made have shown good agreement with experimental data. The efficiency loss due to the mixing of fluid where leakage flow passes the tip gap, which results in growth of a strong vortex, and the fluid passing the blade tip, with almost no work extracted from it, has shown a quite linear efficiency dependence depending on the tip gap size.</p>
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High frequency gas temperature and surface heat flux measurementsIliopoulou, Vasiliki 14 September 2005 (has links)
Further improvements of the thermal efficiency of gas turbine cycle are closely coupled to the increase of turbine inlet temperature. This requires intensive and efficient cooling of the blades. In this perspective, experimental investigations of the gas temperature and heat transfer distribution around the airfoil are of primary importance.
The present work aims at the development of two measurement techniques based on applications of the thin film sensors: the two-layer gauge for the wall heat transfer determination and the dual thin film probe for flow temperature measurements. Both techniques are used in short duration tunnels of the von Karman Institute (VKI) under engine representative conditions and are able to resolve both time-averaged component and time-resolved component i.e. periodic blade passing events at ~5-7 kHz with harmonics up to 50 kHz.
In order to derive the wall heat flux with the two-layer gauge, the unsteady conduction equation is solved in the two-layer substrate using the measured value of the wall temperature as a boundary condition. The gauges are extensively calibrated and the data reduction method is validated on a blade of the second stator of the VKI turbine. A very good repeatability is achieved. Measurements are also performed on the complex geometry of a blade tip in a cascade configuration revealing the high three dimensionality of the flow.
The dual thin film probe combines the operation of two thin films and determines the flow temperature from two independent heat flux measurements. The probe is calibrated and then validated with measurements downstream a cascade. The robustness and the reliability of the probe are also demonstrated by measurements downstream of the rotor and the second stator of the VKI turbine.
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Tooth-anchored vs. bone-anchored maxillary expansion: a randomized controlled trial comparing dental and skeletal effectsCote, Brent 11 1900 (has links)
Aim:To investigate the differences, if any, between tooth-anchored maxillary expansion (TME) and bone-anchored maxillary expansion (BME) in terms of the produced longitudinal dentoskeletal changes -and the stability of these changes- in adolescents with maxillary constriction.
Methods:Sixty two suitable subjects were randomly assigned to one of three groups: (1) TME group; (2) BME group; (3) Control group. Lateral cephalograms, posteroanterior cephalograms, and dental casts were obtained at baseline and at three post-expansion time points. Records from all time points were analyzed.
Results:There were no clinically significant differences between the TME and BME groups at any data collection time point. Both showed initial increases in dentoskeletal widths and dental tipping which were subsequently largely lost to relapse in the absence of retention.
Conclusion:There are no clinically significant differences in the dentoskeletal changes -or the stability of these changes- produced by TME and BME in adolescents with maxillary constriction.
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Omega-3 Fatty Acid Blood Biomarkers Before and After Acute Fish Oil Supplementation in Men and WomenMetherel, Adam Henry January 2007 (has links)
Omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicospentaenoic acid (EPA), are important mediators for cardiovascular disease, fetal/infant development, neurological disorders and inflammatory diseases. Supplementation and washout studies are important for future research on the physiological effects of omega-3 fatty acids and for determination of the proper washout period for future cross-over studies. In this study, omega-3 fatty acid blood biomarker comparisons are made for the n-3 HUFA score (% of n-3 HUFAs in total HUFAs) and omega-3 index (sum of EPA + DHA) in plasma, erythrocytes, whole blood and a novel finger-tip prick blood method (FTPB) of analysis. This FTPB method of fatty acid analysis is further tested to determine the potential for its use in fatty acid analysis. In addition, gender differences in response to omega-3 fish oil supplementation are analyzed in all four blood fractions.
Nine males and seven females were supplemented with 8 fish-oil capsules per day (providing 3.2 g/day EPA and 1.6 g/day DHA) for four weeks, followed by an eight-week omega-3 washout period. Venous plasma, erythrocyte and whole blood samples were collected during weeks 0, 4, 8 and 12 and FTPB samples were collected weekly during supplementation and washout fatty acid analysis was performed.
EPA and DHA incorporation is lowest in magnitude in erythrocytes relative to all other blood fractions. Omega-3 blood biomarker comparisons demonstrate that the n-3 HUFA score is a more reliable measure across all blood fractions compared to the omega-3 index. In addition, the n-3 HUFA score demonstrates no differences (p > 0.05) between FTPB and whole blood analysis, providing evidence to support its usefulness as a tool for fatty acid analysis. However, differences (p < 0.05) do exist between these methods for saturated fatty acid, monounsaturated fatty acids, omega-6 polyunsaturated fatty acids (PUFAs) and omega-3 PUFAs. Baseline fatty acid levels for DHA, and the DHA:EPA and DHA:DPA ratios tend to be higher (p < 0.05) in females, and docosapentaenoic acid n-3 (DPAn-3) is higher (p > 0.05) in males across all blood fractions. Furthermore, a gender effect (p < 0.05) is seen for the DHA:EPA ratio across all blood fractions. At baseline, female DHA:EPA is higher (p < 0.05) than males with supplementation lowering both male and female values and removing any differences (p > 0.05) between genders. Washout results in a return of levels towards baseline, however, baseline levels are not fully reached. Furthermore, while gender differences do begin to reform during washout, these differences are not significant (p > 0.05).
In conclusion, omega-3 fatty acid responses, particularly DHA:EPA ratio, demonstrate significant gender differences that may be related to differences in long-chain PUFA synthesis pathways between males and females. In addition, the n-3 HUFA score may be a more valuable omega-3 blood biomarker than the omega-3 index, as the n-3 HUFA score displays more consistent levels across all blood fractions. Finally, the FTPB method of analysis may be a useful tool in the measurement of fatty acid composition, however, some microwave methylation problems do exist, specifically in the phospholipid class of lipids.
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Modelling, simulation and control of a hydraulic craneHeinze, Alexander January 2008 (has links)
The objective of this thesis is to develop a model that represents the dynamics of a hydraulically operated forestry crane. The model was derived with the traditional Euler-Lagrange formalism and considers the crane mechanics, three double-acting hydraulic cylinders and the valve control unit. On the basis of the derived model we reproduced the entire crane model in MATLAB in order to run simulations herewith. This gave us the possibility to do parameter changes for further studies of the crane in motion. Another major goal within the thesis work was to estimate cylinder friction of the hydraulic actuators. We built up a test rig and used double-acting cylinders for determing their frictional behaviour. For this, we ran open-loop experiments in order to create velocity-friction maps that represented the static friction force of the cylinders. In this concern, we varied system pressure and cylinder load to study their influence on the friction force. By means of the derived static friction maps we approached the cylinder’s dynamic friction behaviour and applied both step and ramp control inputs to examine the spring-damping characteristics of the microspoic bristles in the contacting area. The dynamic friction experiments have been exerted in the fashion of the LuGre model. As a result we acquired different nominal friction parameters that we necessarily used to develope adequate friction models. A third objective of this thesis was to establish a crane-tip control. Instead of a traditional control, providing a direct relationship between joystick input and cylinder extension, the focus was to build up a control for the end-effector’s trajectory in a two-dimensional frame. This could be achieved by using inverse kinematics in order to determine the required joint angles that corresponded to the desired position of the crane-tip. The work also contains a CD including all developed MATLAB models that have been written within this project.
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Anslutning av givare och ett dSPACE-system till en hydraulisk kranJosefsson, Per January 2009 (has links)
Det här rapporten är en del av mitt examensarbete för högskoleingenjörsexamen i elektroteknik vid Växjö Universitet, MSI. Arbetet är en del av ett större projekt kallat Kranstyrningsprojektet som bedrivs av Växjö Universitet, Rottne Industri med flera, vars syfte är att underlätta för förare att kontrollera den kran som finns på Rottnes skotare. För projektet har det använts en laborationskran och nu har önskemålet varit att det till kranen ska installeras ett nytt styrsystem från dSPACE. Dessutom vill man att nya givare ska sättas på kranen och kopplas till dSPACE. Man vill även ha en manual för att nya studenter ska kunna använda systemet. Det nya dSPACE-systemet består av en datorlåda med processor- och I/O-kort. Man kommunicerar med dSPACE från en PC. Arbetet med installationen har stött på flera problem och arbetet har dragit ut på tiden. När systemet till slut gick att använda utfördes ett par tester och sen implementerades det på kranen. Arbete med att ta fram underlag för installation av accelerometrar på kranen pågick samtidigt och en jämförelse mellan olika alternativ gjordes. Arbetet resulterade i att laborationskranen nu går att styra med det nyinköpta systemet från dSPACE och en manual skapades för att underlätta användandet av systemet. / This document is a part of my bachelor degree thesis in electronic engineering was done at Växjö University, MSI. This work is a part of a bigger project called Crane Tip Control which is pursued by Växjö University, Rottne Industri and others, whose purpose is to facilitate for drivers to control the crane used on forwarders from Rottne. For this project, a laboratory crane has been used and they requested that a new control system from dSPACE was installed to the crane. Also they want new sensors to be placed on the crane and connected to dSPACE. A manual should also be created for new students who want to use the system. The new dSPACE-system consists of a computer box with processor- and I/O-boards. Communication with dSPACE is done via a PC. The work with the installation has encountered many problems and the work has been overrun. When the system finally was working, some tests were performed and then the system was installed at the crane. A task to assemble data for installation of accelerometers, was done during the same time and a comparison between different alternatives was made. The work resulted in the laboratory crane is now able to be controled by the new dSPACE-system and a manual was created to facilitate the usage of the system.
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Method development for investigation of real effects on flow around vanesMårtensson, Jonathan January 2010 (has links)
In the development of turbo machinery components it's desirable to not spend more time than necessary when setting up aero-thermal calculations to investigate uncertainties in the design. This report aims to describe general thoughts used in the development of an ICEM-mesh script and the possible configurations in the script file which enables the user to build mesh-grids with/without clearance gap at the hub and/or shroud for different blade geometries. It also aims to illustrate the performance analysis made on the Vinci LH2 turbine, a next generation upper stage engine to the Ariane 5 rocket, in which the effect of the tip gap size on the efficiency has been studied. The calculations made have shown good agreement with experimental data. The efficiency loss due to the mixing of fluid where leakage flow passes the tip gap, which results in growth of a strong vortex, and the fluid passing the blade tip, with almost no work extracted from it, has shown a quite linear efficiency dependence depending on the tip gap size.
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Stability of monoatomic nanowires : a first-principles study / Ab initio studie av nanotrådars stabilitetGerhardsson, Andreas January 2011 (has links)
Monoatomic chain formation for Ag, Au, Pd and Pt has been investigated using a model for the tip structure. First-principles calculations, mostly spin polarized, were performed within the framework of the Density Functional theory. Results are presented and discussed on the basis of the electronic structure. Tendencies for chain formation were noted for Ag, Au and Pt.
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