Thesis (Master of Engineering in Mechanical Engineering)--Cape Peninsula University of Technology, 2018. / The present study was centred on the design of a thermal multistage solar still desalination system. The design is a multistage with new configurations such as direct vapour input into each stage using vapour make-up tubes and the integration of a multistage with a basin type solar still. The incorporation of float a valve in the secondary seawater tank to regulate the seawater in the assembly eliminated the need of pumps to the system. The circulation of seawater between the evaporator and the evacuated tube solar collector (ETC) was through the pressure difference and the flow back was controlled through the incorporation of oneway flow valve. The ETC was used as a heat source to supply the thermal energy into the multistage system. The system had no electrical connections and therefore, no forced circulation as no pumps or any electrical components were used. The system consisted of six stages in total, the evaporator supplied the vapour to five of the six stages of the system. The system was tested on the roof of Mechanical Engineering Department and this location was chosen because of less sun’s intensity obstructions. The system was tested for nine (9) days but the distillate collection was not performed for the whole each day. This was due to the controlled access to the roof and the minor repairs that had to occur before the tests were conducted. The duration on which the tests were conducted varied in each day. The data was supposed to be logged from 08h00 am to 18h00 pm but this was not so due to the controlled access to where the tests were conducted. This data logging period was chosen based on the assumptions that the sun’s intensity would be at maximum within this period. The longest period of test was approximately 7 hours and the system managed to produce about 1500 ml and the maximum temperature for the day was 28oC. The system produced a minimum of 225 ml in the space of 3 hours and the temperature of the day was 26oC. The total amount of distillate produced was about 7600 ml and this amount was produced within the period of 49 hours. The 49 hours is equivalent to two days and 1 hour. It is anticipated that the system would have produced more should there be no repairs involved during the tests. The system produced a maximum of 48 ml at night and a minimum of 8ml in some nights. The night tests were not controlled and monitored due to limited access. It was noticed that the system was empty in each morning of the first few days of the tests. This emptiness contributed to the leakage occurred to the evaporator. The leakage of the evaporator was caused by unmonitored heat supplied by the ETC. The evaporator was constructed using unsuitable material and this was another factor which contributed towards the failure of the evaporator.

The Swedish Migration Agency has, through the years, received criticism regarding its management and assessments of different cases. One of these critiques has been towards the Agency’s management of asylum seekers claiming to have converted as a refugee claim. Therefore, this thesis aims to strengthen the Agency’s management of these cases. Using the critisism made against the Swedish Migration Agency, I suggested recommendation and amendments to the Agency’s established guidelines. The findings in this thesis showed extensive criticism towards the Agency’s usage of religious knowledge tests to assess the genuineness of a conversion. The critic also argues that the Agency lacks religious understanding and that the Agency should focus on identity, community, and faith in a higher power. The analysis presented a need to address religion, the conversion process, and the role of the Agency’s personnel in the guideline.

Det finns flera sätt för en fastighetsägare att minska vakanser. Ett sätt är att konvertera fastigheten, eller delar av den, till ett annat ändamål som passar dagens efterfrågan. Lokalanpassningar har gjorts i alla tider med anledning av att det kan vara dyrare att riva och bygga nytt. En konvertering kan vara bra ur flera olika perspektiv. Ur ett hållbarhetsperspektiv kan det leda till ökade sociala-, ekonomiska- och miljömässiga värden. Under 1970-talet byggdes många kommersiella fastigheter runt om i världen. Historiskt sett har den kommersiella fastighetsbranschen varit cyklisk. Nederländerna var ett land som under 1990-talet led av höga vakanser, framförallt på kontorsfastigheter. Under slutet av decenniet skapades verktyget Conversion Meter som ett hjälpmedel för att bedöma potentialen att konvertera kontorsfastigheter till bostäder.   Idag finns tecken på att kontorsfastigheter inte möter hyresgästernas krav. Effektiva och flexibla kontorsfastigheter i centrala lägen är, ur hyresgästernas perspektiv, en attraktiv arbetsplats. Föråldrade kontorsfastigheter i perifera lägen har en lägre efterfrågan och riskerar i framtiden att få en ännu högre vakansnivå.  Samtidigt finns en stark efterfrågan på bostäder för äldre runt om i landet. Sverige står inför utmaningen att tillhandahålla särskilda bostäder för den åldrande befolkningen. En konvertering av föråldrade kontorslokaler i perifera lägen till denna typ av bostäder kan på många sätt ses som en möjlighet. Några av anledningarna är att fastighetens lokalisering är mindre avgörande, möjlighet att teckna längre hyresavtal till en generellt sett högre hyresnivå än för kontorslokaler samt möjlighet till statliga subventioner. Studien har undersökt möjligheten att utveckla Conversion Meter för att ta fram ett verktyg som kan vara tillämpbart vid en konvertering av kontorsfastigheter till särskilt boende för äldre på den svenska marknaden. Tre fallstudier har genomförts med den modifierade versionen av Conversion Meter. Studien visar att det går att modifiera Conversion Meter. Det modifierade verktyget har i studien kompletterats med en kassaflödesanalys samt med ett tillägg i checklistan för riskbedömning. Studien har visat att verktyget huvudsakligen modifierats utifrån målgruppens preferenser samt svenska byggnadstekniska- och juridiska aspekter.  Fallstudierna visar, med hjälp av kassaflödesanalys, att det är lönsamt att konvertera kontorsfastigheterna till särskilt boende för äldre. Störst lönsamheten visar fastigheten i Upplands Väsby. Beräkningarnas utfall påverkas av kalkylräntan, vakansnivån och skillnader i hyresnivå före och efter konverteringen. Potentiella invändningar mot studien kan vara att vissa parametrar i Conversion Meter inte är tillräckligt precisa samt att verktyget måste kontinuerligt uppdateras efter förändringar i gällande regelverk. / There are several ways for a property owner to reduce vacancies. One way is to convert the property to another purpose. Adaption of properties has always been done due to the fact that it may be more expensive to demolish and rebuild. Conversions of vacant office properties into other uses are desirable from a sustainability perspective because it may lead to an increase in social-, economic-, and environmental values. During the 1970s many commercial properties were built around the world. Historically, the commercial real estate industry has been cyclical.  Netherlands was one of the countries that suffer due to high vacancies during the real estate crisis in the 1990s, especially in office buildings. By the end of the decade, Conversion Meter was created as a tool to assess the potential of converting office properties into housing. Today there are signs that office properties do not meet the tenant’s requirements. Efficient and flexible office properties in central locations are attractive as a workplace. While outdated office properties in less popular locations have a lower demand and hence might have a risk of high vacancy rates. At the same time there is a high demand on housing for the elderly. Sweden faces the challenge of providing care homes for the aging population. A conversion of obsolete office spaces in peripheral locations into care homes can be seen as an opportunity. There are several reasons why property owners would be interested in this market. This includes the location being less sensitive to location aspects, having the possibility to establish long leases, and the ability to receive government grants during conversion as well as generally higher rental levels as compared to office spaces. The main aim of this study is to investigate whether it is possible to develop a modified version of Conversion Meter to measure the potential for converting office properties into housing for elderly in Sweden. Three case studies have been conducted by creating and using a modified version of Conversion Meter with cash flow analysis for office properties in Lidingö, Sollentuna, and Upplands Väsby municipalities. The study shows that it is possible to modify Conversion Meter to measure the potential for converting office properties into care homes. In the study, Conversion Meter has been modified to a Swedish context and a cash flow analysis has been added. Additionally, political risks have been added to the tool. The main differences between the models are the target group's preferences, legal and building law, addition of cash flow analysis, and addition of political risks. By using cash flow analysis, the case studies show that it is profitable to convert office buildings into care homes. The greatest profitability observed is in the property in Upplands Väsby. The outcome of the calculations depends on the level of interest rates, vacancy rates, and differences in rental levels before and after the conversion. Potential biases to the study include parameters in the modified Conversion Meter are not precise and the tool must undergo continuous updates after changes.

Det finns flera sätt för en fastighetsägare att minska vakanser. Ett sätt är att konvertera fastigheten, eller delar av den, till ett annat ändamål som passar dagens efterfrågan. Lokalanpassningar har gjorts i alla tider med anledning av att det kan vara dyrare att riva och bygga nytt. En konvertering kan vara bra ur flera olika perspektiv. Ur ett hållbarhetsperspektiv kan det leda till ökade sociala-, ekonomiska- och miljömässiga värden. Under 1970-talet byggdes många kommersiella fastigheter runt om i världen. Historiskt sett har den kommersiella fastighetsbranschen varit cyklisk. Nederländerna var ett land som under 1990-talet led av höga vakanser, framförallt på kontorsfastigheter. Under slutet av decenniet skapades verktyget Conversion Meter som ett hjälpmedel för att bedöma potentialen att konvertera kontorsfastigheter till bostäder.   Idag finns tecken på att kontorsfastigheter inte möter hyresgästernas krav. Effektiva och flexibla kontorsfastigheter i centrala lägen är, ur hyresgästernas perspektiv, en attraktiv arbetsplats. Föråldrade kontorsfastigheter i perifera lägen har en lägre efterfrågan och riskerar i framtiden att få en ännu högre vakansnivå.  Samtidigt finns en stark efterfrågan på bostäder för äldre runt om i landet. Sverige står inför utmaningen att tillhandahålla särskilda bostäder för den åldrande befolkningen. En konvertering av föråldrade kontorslokaler i perifera lägen till denna typ av bostäder kan på många sätt ses som en möjlighet. Några av anledningarna är att fastighetens lokalisering är mindre avgörande, möjlighet att teckna längre hyresavtal till en generellt sett högre hyresnivå än för kontorslokaler samt möjlighet till statliga subventioner. Studien har undersökt möjligheten att utveckla Conversion Meter för att ta fram ett verktyg som kan vara tillämpbart vid en konvertering av kontorsfastigheter till särskilt boende för äldre på den svenska marknaden. Tre fallstudier har genomförts med den modifierade versionen av Conversion Meter. Studien visar att det går att modifiera Conversion Meter. Det modifierade verktyget har i studien kompletterats med en kassaflödesanalys samt med ett tillägg i checklistan för riskbedömning. Studien har visat att verktyget huvudsakligen modifierats utifrån målgruppens preferenser samt svenska byggnadstekniska- och juridiska aspekter.  Fallstudierna visar, med hjälp av kassaflödesanalys, att det är lönsamt att konvertera kontorsfastigheterna till särskilt boende för äldre. Störst lönsamheten visar fastigheten i Upplands Väsby. Beräkningarnas utfall påverkas av kalkylräntan, vakansnivån och skillnader i hyresnivå före och efter konverteringen. Potentiella invändningar mot studien kan vara att vissa parametrar i Conversion Meter inte är tillräckligt precisa samt att verktyget måste kontinuerligt uppdateras efter förändringar i gällande regelverk. / There are several ways for a property owner to reduce vacancies. One way is to convert the property to another purpose. Adaption of properties has always been done due to the fact that it may be more expensive to demolish and rebuild. Conversions of vacant office properties into other uses are desirable from a sustainability perspective because it may lead to an increase in social-, economic-, and environmental values. During the 1970s many commercial properties were built around the world. Historically, the commercial real estate industry has been cyclical.  Netherlands was one of the countries that suffer due to high vacancies during the real estate crisis in the 1990s, especially in office buildings. By the end of the decade, Conversion Meter was created as a tool to assess the potential of converting office properties into housing. Today there are signs that office properties do not meet the tenant’s requirements. Efficient and flexible office properties in central locations are attractive as a workplace. While outdated office properties in less popular locations have a lower demand and hence might have a risk of high vacancy rates. At the same time there is a high demand on housing for the elderly. Sweden faces the challenge of providing care homes for the aging population. A conversion of obsolete office spaces in peripheral locations into care homes can be seen as an opportunity. There are several reasons why property owners would be interested in this market. This includes the location being less sensitive to location aspects, having the possibility to establish long leases, and the ability to receive government grants during conversion as well as generally higher rental levels as compared to office spaces. The main aim of this study is to investigate whether it is possible to develop a modified version of Conversion Meter to measure the potential for converting office properties into housing for elderly in Sweden. Three case studies have been conducted by creating and using a modified version of Conversion Meter with cash flow analysis for office properties in Lidingö, Sollentuna, and Upplands Väsby municipalities. The study shows that it is possible to modify Conversion Meter to measure the potential for converting office properties into care homes. In the study, Conversion Meter has been modified to a Swedish context and a cash flow analysis has been added. Additionally, political risks have been added to the tool. The main differences between the models are the target group's preferences, legal and building law, addition of cash flow analysis, and addition of political risks. By using cash flow analysis, the case studies show that it is profitable to convert office buildings into care homes. The greatest profitability observed is in the property in Upplands Väsby. The outcome of the calculations depends on the level of interest rates, vacancy rates, and differences in rental levels before and after the conversion. Potential biases to the study include parameters in the modified Conversion Meter are not precise and the tool must undergo continuous updates after changes.

During operation of the solid polymer fuel cell (SPFC). its performance is limited by the concentrations of hydrogen and oxygen at the reaction interfaces and in most SPFC designs, the hydration state of the membrane. Since in general, the concentrations of water and the gaseous species vary along the flow channel, the performance is also likely to change along the flow channel. In order to study this phenomenon, a measurement system was developed to map the current distribution across the electrode surface. The current distribution has been measured by dividing one of the current collectors into a number of electrically isolated segments. The current flowing through each of the segments was measured while maintaining a constant potential across the surface of the gas diffusion layer. Two separate segmented current collectors were developed. The first was used to measure the current distribution for an 80 cm2 single cell, and the second was used to investigate the local current densities around a single flow channel. The effects of the feed gas humidities on the spatial current density in the 80 cm2 fuel cell were investigated for two different membrane-electrode configurations. With Nafion 117 as electrolyte and at a cell temperature of 80°C. the membrane was found to dehydrate in the initial portion of the gas flow channel when the relative humidity of both the hydrogen and oxygen feed gases was less than 50%. With a Gore-Select membrane electrode assembly (hydrogen and air. temperature- 60°C). the membrane was sufficiently hydrated at all feed gas humidification conditions. The performance of the cell was found to deteriorate at higher feed gas humidities as a result of the lower partial pressures of the reactant gases. Measurements of the effects of gas pressures, stoichiometries and humidities on the length-wise and width-wise perfonnance around a single flow channel (Gore-Select membrane electrode assembly) are discussed in relation to a gas flow model.

Since only little is known in the field of Solid Oxide Fuel Cell (SOFC) operation about internal reforming of methane at present, the aim of this thesis study is to conduct a detailed investigation delivering the basis for further experimental and theoretical work. Also information is required if the concept of internal reforming has technical development potential. The thesis is arranged into two major parts being a thermodynamic investigation and an application of a suitable kinetic model. Pure methane tends to decompose at the high operation temperatures of the SOFC (about 950°C) thus forming solid carbon. Therefore it is necessary to include a fuel preparation process delivering H2 and CO that can be utilized by the SOFC. The fuel processing can either be carried out by steam reforming or partial oxidation. It is shown by a thermodynamic investigation that fuel processing by partial oxidation yields a fuel gas of inferior quality than fuel processing by steam reforming. The kinetic part contains the application of a model describing the chemical and electrochemical conversion occuring in the SOFC as detailed as possible at present. This model is used to investigate the thermal behaviour of an SOFC process referring to technical operation parameters. It is shown that internal reforming has technical development potential although a lot of care must be paid to the heat management. Particular operation conditions might exist where the highly endothermic steam reforming process could cause a breakdown of the complete fuel cell process due to its enormous local cooling effect.

No description available.

No description available.

Many wave energy convertors are designed to use either vertical (heave) or horizontal (surge) movements of waves. But the frequency response of small heaving buoys and oscillating water column devices shows that they are too stiff and so their resonance is at too short a period. A device moving in the horizontal (surge) direction has less restoring spring and so its resonance is at too long a period. It follows that a device that moved at some intermediate slope angle could have an intermediate value of hydrodynamic stiffness and so be resonant at a variable and desirable part of the wave spectrum. There have been two series of model tests in this work. The first used a simple free-floating model with no power take-off apparatus and with constraint achieved by means of a large inertia plate lying in the slope plane. The second used a rig that constrained the slope movement of the buoy head by means of hydrostatic bearings running on a guide rod set to the chosen slope angle. An external power take-off system was used to simulate a linear damper for absorbing the incident wave energy and control the motion of the model. This thesis firstly studies the potential of varying the slope angle as a way of tuning the natural period of the device to suit useful wave periods. Secondly, it studies the experimental and theoretical power capture ability of models with different slope angles in regular waves in the frequency domain. The hydrodynamic coefficients of the model were determined both experimentally and numerically based on linear hydrodynamic concepts. The power absorption of the models was calculated using the experimental data of the hydrodynamic coefficients and also measured directly. Some control of power take-off was also investigated. Some irregular wave tests were carried out for the 45 degrees slope angle case. The results show that it is feasible to alter the slope angle of the device as a way of tuning its natural period. However, in further studies of the power capture ability for different slope angles, the device shows a very wide bandwidth and high efficiency performance when it is set to 45 degrees slope angle. This suggests that to constrain the device to a 45 degrees slope angle is suitable for most of the sea states.

Using documentary and ethnographic information, an analogy is drawn between conquest-period (ca. 1722) and contemporary political and religious institutions among the Cora (Nayari) people of the Sierra del Nayar in the Sierra Madre Occidental of Mexico. Fundamental to these political and religious institutions-then and now-is the idea that the deceased elders of the Cora people continue as active agents in the lives of living Coras, particularly as the seasonal rains. Based on this analogy, an inference is extended from contemporary attitudes of Cora people in the town of Santa Teresa toward the political and religious customs that mediate their relationships with these deceased ancestors, to the possible attitudes of Cora people toward their religious customs at the time of the Spanish conquest of the region. Millenarian fear, an anxiety that is widespread in Santa Teresa as contemporary Coras confront their own failure to adequately continue the customs of their ancestors, is inferred to have been a motivating factor in the Cora's acceptance of Catholic religious customs during the colonial period of their history.