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The master’s thesis is focused on the proposal of working part of the hydraulic circuit for the hydraulic press with a press force 400 kN. The thesis contains justifiable structural design of the linear hydraulic motor, which includes material choices, necessary calculations and simulations of material strength characteristics and the choice of the individual components. The thesis also includes a proposal of “heel valve” including the choice of individual components and basic function calculation of the hydraulic circuit of the hydraulic press.

<p><font face="TimesNewRoman"> <p align="left">Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.</p> </font></p>

<p><font face="TimesNewRoman"> <p align="left">Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.</p> </font></p>

Over an extended period of time there have been plans to establish a shared facility in Lennheden to extract groundwater from the Badelunda esker to provide drinking water for the cities of Borlänge and Falun. The city of Falun is dissatisfied with the quality of its drinking water and the city of Borlänge is concerned about the risk of contamination of its existing groundwater supply at its current location. To provide a basis for a decision on this issue, the company Midvatten AB has been commissioned to perform hydrogeological investigations in the area of Lennheden. The purpose of this thesis is to design a functional groundwater model of the area between Lennheden, place of planned extraction, and Övre Tjärna, place of existing extraction, to get a better understanding of the groundwater situation in the area. A groundwater model enables simulations of different scenarios in risk assessment and contaminant transport. The aim of the thesis is that the model can be used as an aid in Midvatten’s investigations in Lennheden and that it also can be used in future projects in the area. The model has been made in Processing Modflow 5.3 and encompasses an area of 19,5 × 11 km along the Badelunda esker and the river Dalälven between Djurmo and Frostbrunnsdalen. The model has 6 layers and a cell resolution of 50 × 50 meters and 50 × 100 meters. The physical parameters of the model are comprised from different hydrological and geological investigations in the area. The Badelunda esker and the river Dalälven totally dominate the groundwater situation in the area. A large part of the work in the thesis has been focused on the calibration of the horizontal hydraulic conductivity in the esker and the vertical hydraulic conductivity in the riverbed of Dalälven. The calibration of the model implies a vertical hydraulic conductivity of 0,01 – 0,1 md-1 in the riverbed of Dalälven, depending on the riverbed thickness. Between Bäsna and Övre Tjärna, simulated and observed groundwater levels correspond well. The transport time of the water in the esker, simulated in PMPATH, also corresponds well with estimated transport times. The model can be used for simpler studies of contaminant transport. Simulation of the pumping test in Lennheden gives a good correspondence eastward in the esker from Lennheden to Övre Tjärna. Westward in the esker, from Lennheden to Bäsna, the draw down is sharper than observed. Possible reasons for the sharper draw down is an underestimation of the bulk of the esker and that the vertical hydraulic conductivity of the riverbed is set too low between Lennheden and Bäsna. In order to improve the model, the most important step should be to thoroughly investigate the river Dalälven with regards to vertical hydraulic conductivity in the riverbed and riverbed thickness. / Under en längre tid har det funnits planer på att upprätta en ny, gemensam vattentäkt för Borlänge och Falu kommun i Badelundaåsen i Lennheden nordväst om Borlänge stad. Falu kommun är missnöjd med vattenkvaliteten i sin ytvattentäkt och Borlänge är oroad över riskerna med att ha sin nuvarande vattentäkt i Badelundaåsen lokaliserad i nära anslutning till riksväg 70 och järnvägen. Beslut i frågan ska tas under 2006 och Midvatten AB har fått i uppdrag att genomföra geohydrologiska undersökningar i och runt Lennheden som underlag till beslutet. Syftet med det här examensarbetet är att skapa en fungerande grundvattenmodell för området mellan Lennheden, plats för planerat vattenuttag, och Övre Tjärna, plats för befintligt vattenuttag, för att få en större förståelse för grundvattenmagasinet. En grundvattenmodell möjliggör simulering av olika scenarion så som föroreningstransport i grundvattnet och bestämning av skyddsområden. Målet är att modellen ska kunna användas som ett komplement i Midvattens undersökningar och även användas i framtida projekt i området. Modellen är gjord i Processing Modflow 5.3 och omfattar ett 19,5 × 11 km stort område längs Badelundaåsen och Dalälven mellan Djurmo och Frostbrunnsdalen. Modellen består av 6 lager där cellernas upplösning är 50 × 50 meter och 50 × 100 meter. De fysiska parametrar som modellen är uppbyggd av är sammanställda från olika hydrologiska och geologiska undersökningar som har utförts i området de senaste 30 åren. Badelundaåsen och Dalälven är de två komponenter som totalt dominerar grundvattensituationen i området. En stor del av arbetet har fokuserats på kalibreringen av den horisontella hydrauliska konduktiviteten i åsen och den vertikala hydrauliska konduktiviteten i Dalälvens botten. I modellen är den vertikala hydrauliska konduktiviteten i Dalälvens botten kalibrerad till intervallet 0,01 – 0,1 md-1 beroende på bottnens mäktighet. På sträckan mellan Bäsna och Övre Tjärna så fungerar modellen bra. Simulerade och observerade grundvattennivåer stämmer väl överens. Även vattnets transporttider i åsen, simulerade i PMPATH, stämmer väl överens med uppskattade transporttider. Modellen kan användas för enklare studier av ämnestransport. Vid simulering av provpumpningen i Lennheden så är överensstämmelsen god österut i åsen, från Lennheden till Övre Tjärna. Västerut i åsen, från Lennheden till Bäsna, är avsänkningen av grundvattennivån för kraftig. Möjliga orsaker till den för kraftiga avsänkningen är att åsens utbredning är underskattad och att Dalälvens botten har en för lågt ansatt vertikal hydraulisk konduktivitet längs sträckan Lennheden – Bäsna. Den klart viktigaste åtgärden för att förbättra modellen skulle vara att grundligt undersöka Dalälven, särskilt längs sträckan Djurmo – Båtsta, med avseende på dess bottens vertikala hydrauliska konduktivitet och mäktighet.

Philosophiae Doctor - PhD / Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.

Philosophiae Doctor - PhD / Research findings in current study provide a new insight into the fractured rock aquifers in the TMG area. Some of the results will have wide implications on the groundwater management and forms a solid basis the further study of the TMG aquifers.

The main objective of this master's thesis is to design the new conception of hydraulic drive of the baling press CPB 100 with application of modern tendencies in the field of hydraulic engineering. This thesis contains design and calculations of new hydraulic drive, hydraulic circuit diagram and the list of hydraulic elements that are used. Moreover this thesis includes the design of an electrical control and the design of hydraulic block and manifold.

Heat energy is important to all aspects of life. Various industries including food processing plants, chemical processing plants, thermal power plants, refrigeration and air conditioning equipments, petrochemical plants, etc. are faced with the problems of effective utilization, conservation and recovery of heat. The production of heat exchangers involves huge investments for capital and operation costs. In view of this, it has become important to design heat exchangers that will be efficient and also save energy, cost and materials. Different techniques known as heat transfer enhancement are employed to achieve this. Of these techniques, the tube-insert technology is applied in the present research. No prior work on heat transfer and fluid flow in a tube induced with twisted tape insert with emphasis on cuts with different geometrical shapes but equal area has been reported. Hence, in the present work, heat transfer and fluid flow of water in tubes induced with twisted tape inserts with different-shape-equal-area cuts is investigated numerically. The present studies pay attention to the thermo-hydraulic characteristics of laminar, transitional and turbulent flows of water through different tube designs fitted individually with twisted tape of different design under uniform wall heat flux. The numerical simulation in this work is carried out by using Fluent software. The RANS-based RNG κ-ε model is employed for the turbulent flow because it is found to give a more accurate result than other turbulence models. Since transitional flow is not fully turbulent, the transitional variant of the SST κ-ω model is applied for the simulation of the transitional flow. The analyses quantify the improvement in the heat transfer, friction factor and thermal performance index in each of the tube systems and these results are used to ascertain the system that gives the best performance. Correlations are also proposed for the Nusselt number and friction factor. The results indicates that the superior fluid mixing provided by the alternate-axis triangular cut twisted tape is one of the reasons why it offers heat transfer enhancement and thermal performance factor that is higher than those that are offered by other induced tubes. Interestingly, the enhancement in heat transfer increases as the size of the cuts on the tape and the width of the tape increase but decreases as the pitch of the tape increases. The enhancement of heat transfer affects the start and the end of the transition to turbulent flow. Transition to turbulent flow occurs and ends earliest in the tube system with the highest heat transfer enhancement. Investigation is also performed on the combined forced and free convection heat transfer in an inclined tube for laminar, transitional and turbulent flows. The induced tube is inclined at different angles (15o≤θ≤90o ) with respect to the horizontal. Importantly, the heat transfer enhancement of the tube systems under mixed convection is higher than those under forced convection, and the enhancement for the mixed convection increases as the inclination angle increases.

Nanofiltration (NF) membranes are used for a range of industrial applications one of which is for the removal of the sulphate constituent in seawater. This is a mature activity for the treatment of seawater that is to be injected into oil reservoirs in the offshore oil/gas industry. Such sulphate removals have also been the subject of much interest, as a pretreatment strategy, in seawater desalination plants that is either utilising thermal technology or reverse osmosis. Nevertheless, there is a need for robust criteria, such as the comparative permeate flux and sulphate rejection, of selecting the optimum NF membrane. There is a major difficulty in the assessment of the comparative filtration performance and the role of membrane structure because the data from manufacturers and also the information from the scientific literature emanates from different testing protocols. This can result in an enigmatical situation for obtaining the optimum NF membrane for a particular application. Against the above background this PhD project has focused on undertaking a fundamental study of different commercially available NF membranes in order to facilitate improved assessment of their filtration performance for sulphate rejection applications in relevant standardised testing conditions. Moreover, on the basis that those variations in membranes’ functioning are attributed to membrane structure and characteristics, a major segment of the research was focused on correlating filtration performance and membrane features. The research comprised two main phases; the first phase involved determining the comparative filtration performance of eight commercially available NF membranes supplied from four manufacturers. The second main phase was to undertake detailed characterisation studies on the NF membranes in order to obtain a clear understanding of their sulphate separation mechanism and permeate flux. The first phase involved assessments of the permeate flux and selectivity of the eight membranes. The experimental protocol in the second, characterisation part of the work was directed to the identification and evaluation of NF active surface layer characteristics:  Pore characterisation by porosity factor calculations,  Hydrophilicity/Hydrophobicity nature by contact angle measurements,  Surface Free Energy calculations,  Surface roughness measurements by AFM,  Membrane potential measurements and average charge density calculations. This approach is an acknowledged strategy for NF membrane scientific research assessment and, in the current work provided key data of membrane features that facilitated a systematic understanding of membrane functioning. These characterisation features were also linked successfully to the membrane performance parameters to yield a characterisation/performance envelope which represents a useful basis for NF membrane selection and utilisation to optimise membrane usage and consequent economic advantage. The general discussion includes a summary of the interface between the role of NF and the operational and economic features of the two main types of desalination processes. It includes an outline of a process scheme for the incorporation of NF pretreatment into an MSF plant from the conceptual design stage as opposed to the application employed hitherto where the emphasis has been on attaching NF pretreatment equipment on to an existing unit. As a result, it is expected that NF usage should increase performance ratio, reduce energy consumption, hence the running cost, and increase recovery.