This master's thesis deals with CFD simulation of vortex rope in the elbow draft tube for overload operation of Francis turbine. The main objective of the thesis is to compare results of the CFD simulations of the original elbow draft tube with a derived straight cone draft tube considering volume and the shape of the cavitation region and dynamic flow characteristic. Results of the 3D simulations are also compared with axi-symmetric simulations, which reduce demands for computing time and power.

In Sweden there are about 350 ice rinks in operation today which consume approximately 300 GWh per year. The average energy consumption for a Swedish ice rink is approximately 1000 MWh per year. Ice rink dose not only consume energy it also rejects heat. The rejected heat comes from the refrigeration system that cools down the ice floor. The refrigeration system rejects heat around 700 to 1000 MWh per season. The reason for this study is because of the rejected heat which leads to the question how the rejected heat can be used.The object is to find a heat pump concept that can use the rejected heat or another heat source in an ice rink. Three different heat pump concepts were evaluated. The first heat pump concept use the ice floor as a heat source (called BHP), the second concept use the rejected heat as a heat source (called CHP) and the third concept use the rejected heat to charge an energy storage (called GHP).To accomplish the objective a heat analysis of two ice rinks were made to be able to simulate the heat pump concepts. With the simulation results a life cycle cost was made for a better evaluation. The results from the heat analysis were used for simulating the heat pump concepts. The two ice rinks that were analyzed were Järfälla ice rink and Älta ice rink. The main heat source the two ice rinks uses today is district heating and electricity. Järfälla only use district heating (DH) as a heat source and Älta ice rink use recovery heat, electricity and district heating.The heat analysis of the two the ice rinks showed that the highest district heating consumer was the domestic hot water at 47% of the DH followed by the dehumidifier at 32% of the DH and last the space heating at 22% of the DH. This shows how the heat is used in a general ice rink in Sweden. The temperature levels for the dehumidifier is around 65 °C (only DH part), the domestic hot water at 55 °C and last the space heating at 20 °C. However the heat demand for the ice rinks resulted in 443 MWh for Järfälla and 192 MWh for Älta. To know the size of the heat pump used for the heat pump concepts a heat profile for the ice rinks were made. The result of heat profiles lead to a heat pump size of 105 kW in Järfälla and 45 kW in Älta. The rejected heat for one season in Järfälla is 1000 MWh and 780 MWh in Älta.With the results from the heat analysis the evaluation the heat pump concepts was possible. The COP1 for the CHP resulted at 3,8 and the COP1 for the GHP was assumed to be the same as for the CHP. The COP1 calculations for the BHP concept resulted at 2,5. COP was calculated with collected data from the respective ice rinks refrigeration system. The simulations results were that the BHP and the CHP concept could fulfill the heat demand up to around 79% and the GHP up to around 84% in both ice rinks. The rest of the heat demand is heated with supplementary heat. The life cycle cost (LCC) showed that the CHP concept had the lowest cost followed by the GHP concept. The BHP concept had the highest LCC, because of the low COP. The LCC model dos not include the running cost, the maintenance cost and the energy tariffs for the district heating.The recommended solution is the GHP concept. This is because it is a good investment for the future since other buildings can be connected to the energy storage. The GHP concept is also the solution that fulfills the heat demand best and has the lowest annual energy cost.

I dagens arbete har lärare för hög arbetsbelastning och därför har deras arbetssituation försämrats. På arbetsplatser har psykiska, fysiska och sociala hälsan en viktig roll för att människor ska uppleva hälsa på arbetsplatser. På högskolor runt om i Sverige kan flera arbetsrelaterade problem äga rum som kan bidra till att lärarnas arbetsförmåga kan försämras. I avseende till detta kan lärarnas arbetssituation bli ett lidande problem som kan resultera till ett bristande stöd från sin verksamhet. Syftet med studien var att belysa hur lärarna upplever sin hälsa på arbetsplatsen och hur HR- avdelningen kan stötta dem för att kunna möjliggöra deras arbetsuppdrag på högskolan. Studiens tar sitt teoretiska utgångsläge i tvåfaktorsteorin, community of practice, det salutogena perspektivet och KASAM. Studiens material utgick från semistrukturerade intervjuer och analyserades utav en kvalitativ innehållsanalys. Resultatet av studien visade bland annat att lärarna uppskattar flexibla arbetstider och möjligheter att arbeta självständigt eller i grupp och det finns en efterfrågan av kunskapsmetoder som främjar arbetsmiljön. Upplevelsen i nuläget är att det saknas hälsofrämjande insatser från högskolans ledning för att arbetsengagemang inte är tillräckligt. Däremot kan ett utvecklat HR-arbete skapa bredare möjligheter för att förbättra anställdas hälsa vilket kan resultera i att hälsa på arbetsplatsen kan öka och bidra till delaktighet i arbetsuppdrag hos de anställda på högskolan. Sammanfattningsvis upplever lärare att det finns en god arbetshälsa och arbetsmiljö.

Author: Bc. Simona Bartošová Title: Effect of sensomotoric insoles on postural stability in children with cerebral palsy Objectives: Objectively assess the effect of sensomotoric insoles on children with cerebral palsy (CP) via COP (Centre of Pressure) parameters recorded on Kistler force plate. Methods: This thesis is designed as an experimental study. Selected paramaters of static postural balance were recorded via force plate to assess the effect of sensomotoric insoles. Five subjects (average age 7.2 years) with diagnosis of cerebral palsy were enrolled into the study. Data collection was carried out in two separated sessions - first before therapy and second after using the insoles for one month. The validity of the data was supported by three repetitions for each modification - upright plain stand with open eyes, upright stand with feet together and upright plain stand with closed eyes. Monitored parameters were: total trajectory of COP, amplitude of mediolateral displacement of COP, amplitude of anteroposterior displacement of COP and mean velocity of movement of COP. The data were analyzed in MATLAB® version R2019b. The statistical analysis was performed including the outliers elimination. The normality of data was checked by Lilliefors' test. In the case of normality a two-sample Student's...

A ground source heat pump (GSHP) system utilizes a borehole heat exchanger to extract energy from the ground during the heating season and to deposit energy during the cooling season. This requires the drilling of an extended borehole, typically ranging from 100 to 200 meters in length, with a diameter of approximately 6 to 8 inches. Inside the borehole, a U-shaped tube is placed and surrounded by a grout that aids heat transfer between the tube and the surrounding soil. A heat transfer fluid, often a mixture of water and glycol, circulates through the tube to exchange heat with the ground. During the winter, the system draws energy from the ground for household space heating, while in the summer, when air conditioning is used, it expels energy from the house into the ground. In regions with heating-dominated climates, such as Canada, more energy is withdrawn from the ground during the winter than can be naturally restored during the summer. Consequently, the soil progressively cools over time, leading to reduced heat pump coefficient of performance and a decline in the overall system efficiency. This study explores a solution to this issue by integrating solar domestic hot water systems which employ solar thermal collectors to heat water for domestic purposes. These systems are relatively straightforward, consisting of solar thermal collectors, piping, pumps, a hot water tank, and controllers. The collector area is designed to deliver high solar fractions during the summer, but it typically exhibits lower efficiency in the winter. In Toronto, annual solar fraction, defined as the proportion of energy supplied by the solar thermal system to the total energy required by the load, typically range between 50-70%. This research aims to leverage solar thermal collectors for recharging the ground during the summer months. This approach enables the installation of larger collector areas, improving system performance in the winter, while simultaneously depositing excess energy into the ground during the summer. Notably, this study focuses on a single household located in Toronto, Canada, where the recommended solar thermal collector area is 10 square meters, and the borehole heat exchanger length is 150 meters. Also, it is assumed that four people are living in this house and required energy for heating and cooling of the house are 28000 and 7000 kWh per year, respectively. This approach offers a promising solution to balance seasonal heat transfer to the ground, mitigating the long-term decline in GSHP performance. The study demonstrates that by coupling the solar thermal system with the GSHP, the targeted outcomes are achievable. / Thesis / Master of Applied Science (MASc)

No description available.

The term Community of Practice (CoP) is often used rather loosely to describe many types of instructional settings that support more constructivist or social learning settings. This study differentiates CoP from other learning communities with greater discipline in defining CoP, as characterized by sustained self-organization for example. Such a CoP sits quite apart from the typical intent of instructional settings. The literature on intentional CoP suggests that the greatest challenges are a sense of interdependence among CoP members, the authenticity of the practice or purpose, and a trajectory for the CoP's future. The purpose of this case study was to attend to these issues with an online initiative to nurture CoP among practicing teachers in a reading-specialist, graduate program. For the course under study, learners engaged only in cooperative projects with the support of a community worksite (Sakai). Throughout the term, the worksite was promoted as a community place independent of the course and program, a place where they could continue to share indefinitely; and they were encouraged to think of what formal and informal activities the system could support, and how. The study explored how participants responded verbally and behaviorally to the community worksite and the other technologies employed to better support their group work and sharing of knowledge in general. The group's technical skills, competing cultures and practices, and the level of authenticity were all significant challenges. The study's findings challenge the application of this learning theory at the course level of academics, and they inform future design of online support for intentional CoP. / Ph. D.

Yes / The performance of Ground Source Heat Pump (GSHP) systems for domestic use is an increasing area of study in the UK. This paper examines the thermal performance of three bespoke shallow horizontal GSHP systems installed in newly built residential houses in the North of England against a control house which was fitted with a standard gas boiler. A total of 350 metres of High Density Polyethylene pipe with an external diameter of 40 mm was used for each house as a heat pump loop. The study investigated (i) the performance of a single loop horizontal Ground Heat Exchanger (GHE) against a double loop GHE and (ii) rainfall effects on heat extraction by comparing a system with an infiltration trench connected to roof drainage against a system without an infiltration trench above the ground loops. Parameters monitored for a full year from October 2013 to September 2014. Using the double GHE has shown an enhanced performance of up to 20% compared with single GHE. The infiltration trench is found to improve performance of the heat pumps; the double loop GHE system with an infiltration trench had a COP 5% higher than that of the double loop GHE system without a trench.

Approximately 44,965 people committed suicide in 2016 in the United States, and the rate has been rising for a decade and a half. Suicide has far-reaching consequences which affect not only the victim, but those close to the person as well. For every suicide, an estimated six people are futher traumatized, bringing the current loss survivor estimate to over 5 million. Additionally, suicide costs tax payers about 70 billion dollars annually. Despite outranking homicide as a leading cause of death, the long-standing stigma associated with suicide creates a barrier for open and effective communication about the issue. This paper investigates the changing attitudes about suicide across time, the impact of the interacting factors of gender, age, sexuality, and depression, current suicide myths, the trend of suicide by cop, and discusses future needs for research and effective intervention and prevention.

This study investigated beliefs of members of an online Community of Practice (WIA) on the role of the community on professional development, teaching, and on Web 2.0 use. Through the analyses of the questionnaire, it was aimed at finding out the members&rsquo / ideas about the group as an online CoP and benefits of belonging to an online CoP. The data were collected from seventy nine members of the Webheads in Action from various countries by using an online questionnaire. Then, the responses to the multiple choice items were analyzed using PASSW. The data collected from the last section of the questionnairre were analyzed through content analysis and pattern coding. The findings revealed that the members believe that WIA plays an important role in the process of developing multiltiteracies skills and the Web 2.0 tools used in classroom teaching and for professional development. The findings also revealed that the participants believe that being a WIA member leads to motivation, collaboration and discovery. These beliefs are thought to provide insights about the advantages and disadvantages of learning in online CoPs and their effects on the members&rsquo / Web 2.0 use. The findings can also be beneficial for researchers, teacher trainers, and teachers wishing to join CoPs for professional development. They can understand the advantages and disadvantages, and the participation process in more detail. Moreover, these findings can indicate that online CoPs can provide a medium for coping with the increasing amount of information thanks to the recent technological developments, and acquiring new skills.