Molecular distillation is that process of free transfer of molecules under high vacuum from an evaporator to a condenser, where the distance of travel is within the limits of the mean free path of the vapor molecules in the residual gas. Under these conditions, distillations can be made at temperatures 100 to 150°C. lower than ordinary distillations. Many of the so-called "undistillables“ can be distilled under conditions existing in the molecular distillation process. The natural fats and waxes, sugar derivatives, petroleum residues, plastics, and plasticizers now fall within the scope of molecular distillation. The use of the molecular distillation process is now limited by the high costs involved. Thermal efficiency is low, only 2% of the total input heat is utilized for distillation. The separating powers of molecular stills are low, never more than that of one ”theoretical plate“. Only those materials that can bear the high process costs are now being produced commercially, the production of vitamins being the most prominent. Considerable work has been done relative to the development of molecular stills. Advancement to the present day centrifugal stills has been accomplished relatively recently. Many problems are yet unsolved. Much work must be done before molecular distillation can be placed on a level with other methods of distillation. An increase in thermal efficiency, an increase in separating powers, a decrease in film thickness, and a lowering of the costs of the process are necessary. The purpose of this investigation was to design and construct a five inch centrifugal molecular still. Four interchangeable rotors were employed, each of different thickness, different diameter, and having a different angle of inclination. The effect of angle of inclination on film thickness can then be studied. Although no data has been published relative to still performance of five inch commercial stills, data obtained from the operation of the still constructed in this investigation can be compared when such data is published. / Master of Science

Yes / The desalination of saltwater is a viable option to produce freshwater. All the desalination processes are energy-intensive and can be carried out on a large scale. Therefore, producing freshwater using renewable energy sources is the most desirable option considering the current energy crisis and the effect that fossil-fuel-based energy has on our carbon footprint. In this respect, the tray-type still, one of several solar power desalination still varieties, is popular owing to its straightforward design, economic materials of construction, and minimal maintenance requirements, especially in isolated island regions with restricted energy and natural water supplies. The traditional tray-type solar power has a few drawbacks, such as the inability to recover latent heat from condensation, reduced thermal convection, a large heat capacity, and comparatively minimal driving power through evaporation. Therefore, the improvement of heat and mass transfer capabilities in tray-type stills has been the subject of many studies. However, there is a lack of a comprehensive review in the open literature that covers the design and operational details of multistage solar stills. The purpose of this paper is to present a thorough overview of the past research on multistage solar stills, in terms of configurations, capabilities, and cutting-edge options. In comparison to a unit without a salt-blocking formation, the review indicates that a multistage distillation unit may run continuously at high radiation and generate pure water that is around 1.7 times higher than a unit without a salt-blocking formation. The most effective deign is found to be “V”-shaped solar still trays that attach to four-stage stills, since they are less expensive and more economical than the “floor” (Λ-shape) design, which requires two collectors. Additionally, it can be stated that the unit thermal efficiency, solar percentage, and collected solar energy (over the course of a year) increase by 23%, 18%, and 24%, respectively, when the solar collectors are increased by 26% (at the constant inflow velocity of the water).

La scène théâtrale postdramatique, telle qu'Hans-Thies Lehmann la décrit, a souvent recours à la mise en place d'éléments de réel et de fiction qu'elle proclame comme tels. Ce faisant, elle se rallie à la discipline de la performance et porte le spectateur à percevoir le théâtre en tant que « processus » de création et de représentation. La série photographique Untitled Films Stills de Cindy Sherman interpelle le public d'une façon similaire, par l'ambiguïté entre le réel et le simulacre que le sujet photographié, toujours Sherman, met en place. Nous constatons que plutôt que de présenter des illusions parfaites, le photographique et le postdramatique témoignent d'une volonté de produire des instants fictionnels qui s'affichent pour produire un discours sur le réel, leur pratique et sur les actants qui y participent. Le premier chapitre de ce mémoire convoque quelques théories concernant l'œuvre de Cindy Sherman. Le courant photographique dans lequel sa pratique s'inscrit, ses inspirations majeures, soit Diane Arbus et Andy Warhol, tout autant que l'inscription de sa démarche artistique sur son propre corps, confèrent à l'artiste une grande singularité. Nous appliquant par la suite à l'examen des illustres Untitled Films Stills, nous relevons les raisons pour lesquelles cette série évoque en nous un caractère énigmatique. Nous appuyant sur les théories de Rosalind Krauss, Régis Durand et Arthur Danto, nous soulevons la dualité entre le réel et la fiction que met en lumière l'œuvre de Sherman. Une fois l'œuvre initiatrice exposée, nous définissons les composantes esthétiques générales du théâtre postdramatique en nous attardant davantage au texte, à la présence et à la réception du public. Nous effectuons cette réflexion en regard de l'ouvrage intitulé Le Théâtre postdramatique d'Hans-Thies Lehmann. Nous nous intéressons ensuite à la notion de performance et plus particulièrement à l'idée de « présent continu » et de « marge » du théâtre tels que décrits par Josette Féral. Nous montrons par la suite pourquoi il est judicieux de recourir à la forme postdramatique pour créer notre essai scénique, qui divulgue notre point de vue sur l'œuvre de Cindy Sherman. L'essai scénique produit dans le cadre de cette maîtrise est l'exemple auquel nous recourrons afin de montrer que l'utilisation de quatre caractéristiques stylistiques du théâtre postdramatique (la mise en musique, l'irruption du réel, la parataxe et la simultanéité des actions) peut engendrer un discours à la fois sur l'œuvre citée, notre point de vue par rapport à celle-ci, ainsi que sur l'acte théâtral. Nous présentons comment nous avons décortiqué sur la scène, ce que l'instant et l'acte photographique chez Cindy Sherman condensent et camouflent partiellement à notre avis, révélant ainsi notre point de vue quant à l'œuvre initiatrice de ce projet. Étaler sur scène les souvenirs populaires, qu'évoquent en nous les photographies de Cindy Sherman, nécessite un examen attentif de ce qu'elles renferment. Écrire, mettre en scène et agir à titre de performeuse au sein d'un spectacle qui divulgue notre point de vue sur une œuvre, suppose non seulement de se commettre en tant que personne, mais également d'exposer la mémoire de sa propre culture. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Théâtre postdramatique, Cindy Sherman, Untitled Films Stills, Photographique, Réel

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2015. / Access to adequate quantities of clean drinking water has become a serious issue on the worldwide level. This is particularly true in arid and rural areas where for the majority of people water is a limited and a vulnerable resource. These water sources which are often highly contaminated are potentially the cause for several diseases (waterborne diseases) and ultimately death especially in infants. Due to poverty and sometimes to the remote conditions of their regions, the population is unable to afford adequate water purification technologies, since they are relatively expensive and energy intensive. It is therefore vital to investigate appropriate water purification technology that people can afford or construct, operate and maintain themselves. A promising technology is solar distillation for the supply of drinking water on a small-scale level. It has proved to be a unique purification method as it can purify almost any type of water by using the high solar energy potential of the affected regions. The most basic form of solar distillation is the use of a single basin single slope solar still. However the downside of this technology is that it presents a low efficiency and productivity. To try to tackle this problem, many studies have been carried out to enhance productivity, effectiveness and efficiency of single-basin solar stills. In this present study, a solar distillation unit was designed, fabricated and experimentally tested. Its performance in terms of distillate output and energy efficiency was analysed under Cape Town conditions and compared to similar stills that have been reported in the literature. The main configuration of the solar still is a double glazed single basin solar still coupled to an external condenser. The study indicated that the performance of the solar still unit can be enhanced by increasing the evaporation rate which is a combined effect of solar radiation, ambient temperature, and the system components temperature. It was concluded that the applied techniques such as the external condenser, double glazing, good insulation and low level of water are effective. The unit was found to have an efficiency ranging between 21 and 29% over the test period and a mean distillate yield of about 2.5 litres per square meter was achieved per day.

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.

Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: The objective of this research was to obtain clean drinkable water from treated sewage effluent by using a solar-powered distillation cycle. Technologies and concepts were borrowed from the solar desalination industry to propose a unique circular distillation cell design. From the design, a specific mathematical correlation was developed to predict the distillate mass flow rate by using only evaporation and condensation temperature as inputs. This model was incorporated into a simulation model built using Transient System Simulation software. Long-term simulations were carried out to determine the operating capabilities of the design. A prototype was successfully constructed and operated. Experimental results indicated good agreement with the mass flow rate mathematical correlation. Water quality levels were tested against the South African National Standard 241 national drinking water quality standard. Four quality parameters are outside acceptable levels. Evidence suggested that acceptable quality levels could be reached. The circular distillation cell design is a major contribution made by this research. Another contribution is the simulation model capable of predicting an output for different locations. Finally, the proposed prototype is potentially a very valuable device contributing towards the reduction of consumer demand in terms of water and energy as well as the household load on the wastewater treatment system. / AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om te beskryf hoe behandelde rioolwater deur middel van ’n son aangedrewe distillasiesisteem gesuiwer kan word om drinkbare water as eindproduk te lewer. Die nodige tegnologieë en konsepte is oorgeneem uit kommersiële sonaangedrewe ontsoutingsisteme om met ’n unieke ontwerp voorendag te kom wat uit ’n sirkelvormige natuurlike konveksie distillasiesel bestaan. Met behulp van hierdie ontwerp is ’n wiskundige korrelasie ontwikkel om die gesuiwerde water se massavloei te bepaal. Slegs die verdampings- en kondensasietemperature word as insetwaardes gebruik om die massavloei te bereken. ’n Simulasiemodel is met behulp van die Transient System Simulation programmatuur gebou. Die wiskundige korrelasie is by die simulasiemodel geïnkorporeer om langtermynsimulasies te kan uitvoer. Voorts is ’n demonstrasiemodel suksesvol gebou en aangedryf. Eksperimentele resultate toon goeie ooreenstemming met die simulasieresultate. Die gesuiwerde water se gehalte is met die nationale SANS 241 drinkwaterstandaard as maatstaf getoets. Slegs vier gehalteparameters val buite die aanvaarbare vlakke, hoewel dit blyk dat hierdie elemente wel tot aanvaarbare vlakke verlaag kan word. Hierdie navorsing se grootstet bydrae is die ontwerp van die unieke sirkelvormige distillasiesel. ’n Bykomende bydra is die aanpasbaarheid van die simulasiemodel sodat dit produksievermoë op verskillende plekke kan voorspel. Die demonstrasiemodel is ’n potensieel waardevolle ontwerp wat kan bydra tot die verlaging in verbruikersaanvraag na water en energie. ’n Ontwerp van hierdie aard kan die las wat huishoudings op suiweringaanlegte vir rioolwater plaas, verlig.

This works explores how to work with Event scores as a design method. In the search for what is real or what is reality the already existing things are being explored. The work started with investigating suitable ways to work with the moving body in the design process, with the aim to find a method that gave control but also left some parameters to the undecided and ambiguous. Convinced that this will lead to something new some parts of the process were highlighted and re-formulated. / Program: Modedesignutbildningen