This master’s thesis deals with changing the geometry of the output section of the impeller of the radial centrifugal pumps and its influence on the characteristics of the pump. In engineering practice for these radial centrifugal pumps it is possible to change the parameters based on the requirements. This adaptation of parameters is called impeller trimming. Impeller trimming means the reduction of the impeller diameter thereby decreasing the flow, head and efficiency. Existing equations for calculating the changes in the characteristics of the impeller trimming are inaccurate. In this thesis is describes a possible method of putting for the recalculation characteristics of a pump based on the impeller diameter on the available characteristics of pumps.

As more and more trips increase in the decades, the conflicts between the participants are more and more frequent. The main topic of the thesis is to study the impact of the conflicts: the impacts of conflicts between right turn motor vehicles and pedestrians at signalized intersection. The study focus the impacts on urban area. In these areas, the conflicts between pedestrians and motor vehicles are particularly distinct. The situation thesis describes is: most of the signalized intersections whose signal for right-turn vehicle and pedestrian going through are at the same phase, thus unavoidably causes a lot of conflicts between pedestrians and motor vehicles during that time, and it also brings about a great chance of accidents as well. The behavior of motor vehicles drivers and pedestrians highly affects the how they will be conflicted. In addition, the impacts could be different with different flow of motor vehicle and pedestrians. In this process, gap acceptance of the pedestrian weighs a lot. And two models are used here to analyze the conflict. One is from the Swedish Capacity Manual and the other is from HCM 2010. In the thesis, a typical signalized intersection is chosen and the video are recorded to obtain data. The thesis discusses the differences of the two models, and some observed behaviors. And, according to the result, 500 pedestrian flow increase will bring 100 saturation flow rate decrease; and pedestrians flow at peak hour will increase travel time of motor vehicle over 100%. After that, some further studies and alternate methods are discussed.

Around 50 million tones hematite iron ores with high iron content at a grade of 68% were found in Muko area of Uganda. Currently, the iron and steel making industry in the country has not yet developed to meet the demand to process the natural ores. Based on the analysis of its composition and mechanical properties, I infer that the natural iron lump ores can charge directly into reduction furnace without any prior treatment, so that the cost of whole process without additional enrichment and sintering will be reduced quite much. Also direct reduction iron (DRI) process use natural gases instead of coals which can greatly reduce the environmental pollution and lower the processes cost. If the raw materials that fit for requirements of majority plants, the seller´s market can get greater control over prices, terms due to the easy and cheap processing. All lump ores were from Butare area which is one occurrence of Muko and named sample A in this work. This research aims to use the lowest cost method to reduce Butare area iron ores and find out the optimum parameters on reduction reactions of Butare iron lump ores, such as flow rate, temperature, size of samples. Base on experiments with different designed parameters, Butare iron lump ores successfully reduced by DR furnace and microstructure was found to be an important parameter that strongly influent reduction degree of Butare iron lump ores.

No description available.

Particle image velocimetry (PIV) is an optical flow measurement technique that is used to measure volume flow rate at the exit of a turbulent, round nozzle. The objective of this thesis is to determine how to best make this measurement. The quality of the measurement is affected by a range of data acquisition parameters and how data are processed. Measurements are made over a range of different flows using the two main types of PIV: Two Component (2C), which uses one camera, and Stereo, which uses two cameras, similar to human eyes. Previous work done for data acquisition and processing of PIV in general is found to apply. Different parameters are tested, evaluated, and discussed. Both 2C PIV and Stereo PIV were found to underestimate flow by approximately 2%.

京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第20039号 / 地環博第155号 / 新制||地環||31(附属図書館) / 33135 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 藤井 滋穂, 准教授 田中 周平, 准教授 大下 和徹 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

Communication by voice is foundational in our society and many rely on their voices for their occupations. Voice disorders affect a significant number of individuals each year, and diagnosis and treatment improvements are therefore sought via advancements in voice research. Contained in this thesis is a description of work intended to contribute to vocal fold research by using synthetic, self-oscillating vocal fold replicas to study the impact of replica vibration on perfusion fluid flow through the replica. Methods for manufacturing vocal fold replicas containing imbedded channels allowing for fluid perfusion are discussed. Experimental procedures developed for delivering perfusion fluid to the imbedded channel at a constant pressure during replica vibration are described. Methods for measuring perfusion parameters of perfusion fluid pressure, imbedded channel diameter, flow rate, and vibration parameters (subglottal pressure, frequency, amplitude, channel length, and glottal width) are detailed. Experiments performed using both stationary and vibrating vocal fold replicas are presented. Correlations between perfusion pressure and channel diameter are discussed. Vibration parameters were correlated to perfusion flow parameters and it is shown that perfusion flow rate through the channels decreased significantly with model vibration. Potential mechanisms for changes in perfusion flow resistance with vibration are discussed and analyzed. Output of a theoretical model, developed to incorporate some of the possible flow resistance mechanisms, was compared to vibrating replica experimental data.

This thesis presents results of an experimental investigation that characterizes the wall vibration of a pipe with turbulent flow passing through it. Specifically, experiments were conducted using a water flow loop to address three general phenomena. The topics of investigation were: 1) How does the pipe wall vibration depend on the average flow speed, pipe diameter, and pipe thickness for an unsupported pipe? 2) How does the behavior change if the pipe is clamp supported at various clamping lengths? 3) What influence does turbulence generation caused by holed baffle plates exert on the pipe response? A single pipe material (PVC) was used with a range of internal diameters from 5.08 cm to 10.16 cm and diameter to thickness ratios ranging from 8.90 to 16.94. The average flow speed that the experiments were conducted at ranged from 0 to 11.5 m/s. Pipe vibrations were characterized by accelerometers mounted on the pipe wall at several locations along the pipe length. Rms values of the pipe wall acceleration and velocity time series were measured at various flow speeds. Power spectral densities of the accelerometer data were computed and analyzed. Concurrent wall pressure fluctuation measurements were also obtained. The results show that for a fully developed turbulent flow, the rms of the wall pressure fluctuations is proportional to the rms of the wall acceleration and each scale nominally as the square of the average fluid velocity. Also, the rms of the pipe wall acceleration increases with decreasing pipe wall thickness. When changes were made in the pipe support length, it was observed that, in general, pipe support length exercises little influence on the pipe wall acceleration. The influence of pipe support length on the pipe wall velocity is much more pronounced. A non-dimensional parameter describing the pipe wall acceleration is defined and its dependence on relevant independent non-dimensional parameters is presented. Turbulence was induced using baffle plates with various sizes (2.54 cm to 0.159 cm) and numbers of holes drilled through them to provide a constant through area of 35.48 cm2 for each plate. Cavitation exists at high speeds for the largest holed baffle plates and this significantly increases the rms of the pipe wall acceleration. As the baffle plate hole size decreases, vibration levels were observed to return to levels that were observed when no baffle plate was employed. Power spectral densities of the accelerometer data from each baffle plate scenario were also computed and analyzed.

The future of companies that are founded on the development of new and innovative products is threatened when competitors reverse engineer and imitate the products. If the original developers could predict how long it would take a competitor to reverse engineer a product, it may be possible for them to delay, if not prevent, that competitor's entry into the market. Metrics and measures have been developed that can estimate the time it would take an individual to reverse engineer a product. The main purpose of these metrics and measures is to help designers determine how quickly a competitor could reverse engineer a product and develop and market a competing product. A critical parameter of these metrics is the flow rate of information (how quickly information can be extracted from a product), which is a parameter unique to each individual. This thesis seeks to establish a method for creating probability distributions that could be used to select a reasonable flow rate for an individual, by using data collected on the initial flow rate of multiple individuals.

Background: Radiation therapy used for head and neck cancer patients cause many side effects in the oral cavity and above all affects the salivary glands. Complaint of dry mouth (xerostomia) and hyposalivation are common as well as swallowing difficulty (dysphagia) even after the cancer is remitted.  Aim: The aim of the study is to examine the correlation between hyposalivation and xerostomia in patients undergoing radiotherapy.   Methods: Six patients undergoing radiotherapy for head and neck cancer at Norrlands University Hospital participated in the study. A questionnaire regarding xerostomia was answered and a collection of stimulated as well as unstimulated saliva was taken.  Results: Regarding the stimulated salivary flowrate, one out six patients was below the limit of hyposalivation. Three out of six patients were below the limit of hyposalivation with reference to the unstimulated salivary output. The questionnaire regarding xerostomia showed that all patients experienced dry mouth symptoms to varying degrees. The questions concerning the dryness of the tongue and the amount of saliva in the mouth had the highest rating.  Conclusion: Regarding the patients that participated in this study, a correlation is shown between xerostomia and unstimulated salivary output. However, due to the lack of participants in the study, no firm conclusion can be drawn.