Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Distillation column design and operation require understanding of both the hydrodynamic and thermodynamic behaviour and limitations. One of the hydrodynamic aspects that negatively influence separation efficiency in the distillation column is entrainment of the liquid with the rising vapour or gas. Inaccurate entrainment predictions will lead to poor separation efficiencies in the column and consequently over design of the column diameter and/or height has to be incorporated. This has a significant impact on the capital cost due to the size and scale of industrial columns. Therefore, small improvements in entrainment prediction will lead to large savings in capital investment. Previous research published in the open literature focused primarily on the influence of gas and liquid flow rates and, tray geometry on entrainment for the air/water system. Consequently the non-air/water database is small and consists of data obtained from various tray and column geometries. As a result the accuracy of current entrainment prediction models is questionable for systems other than air/water. Therefore, the first objective of this work was to investigate whether current prediction models perform well for systems other than air/water. To prove this air/water, air/ethylene glycol and air/silicon oil data were measured and compared with current prediction correlations. It was found that current prediction models perform poorly for the air/ethylene glycol and air/silicone oil systems. At the same time a new observation was made with regard to froth development and behaviour inside the column. The observation shows that liquid flow rate has a nonmonotonic influence on entrainment, caused by the short (475mm) tray flow path. The second objective was to examine the influence of gas physical properties on entrainment. New entrainment data were measured by individually contacting air, CO2 and SF6 with water and ethylene glycol, while n-butanol was contacted with CO2 and SF6. The data was compared with current prediction models which performed poorly for SF6 results. This shows the inability of these models to predict entrainment for gas systems with high densities. Modified Reynolds and Froude numbers were developed to show the influence of gas physical properties on entrainment. Low modified Reynolds numbers and large modified Froude numbers resulted in high entrainment. The third objective was to determine the influence of liquid physical properties on entrainment. New entrainment data were measured using CO2 with Isopar G, n-butanol, water, silicone oil and ethylene glycol. Current prediction models compared poorly to the data and did not include the influence of liquid viscosity on entrainment. It was found that viscosity had an intricate non-monotonic influence on entrainment. The fourth and final objective was to correlate the influence of gas and liquid properties on entrainment as determined by the previous two objectives. To make the dataset more complete, entrainment was measured for four tray spacings using CO2/Isopar, CO2/nbutanol, air/ethylene glycol, CO2/ethylene glycol, air/silicone oil and CO2/silicone oil (over 1700 data points). Two new correlations are presented to predict the fraction of liquid entraining with the rising gas (L’/G with R2 = 85%) and the fraction of liquid entering the tray that entrains (L’/L with R2 = 92%). The performance of the L’/G correlation (R2 = 85%) is vastly superior to two other prominent correlations (R2 = 61% and 23%). This correlation can be implemented to predict entrainment successfully for different tray geometries by combining the predicted influence of tray geometry, by Kister and Haas (1988), with results from the newly developed correlation. All four objectives are presented as manuscripts for journal publication and serve as alone standing documents. / AFRIKAANSE OPSOMMING: Distillasie kolom ontwerp en bedryf vereis begrip van beide die hidrodinamiese en termodinamiese gedrag en beperkings. Een van die hidrodinamiese aspekte wat skeiding doeltreffendheid negatief beïnvloed in die distillasie kolom is meesleuring van die vloeistof met die stygende dampe of gas. Onakkurate meesleuring voorspellings sal lei tot swak skeiding doeltreffendheid in die kolom en gevolglik word die ontwerp van die kolom deursnee en / of hoogte beinvloed. Dit het 'n beduidende impak op die kapitale koste as gevolg van die grootte en skaal van industriële kolomme. Klein verbeterings in meesleuring voorspelling sal dus lei tot groot besparings in kapitaal belegging. Vorige navorsing gepubliseer in die oop literatuur het hoofsaaklik gefokus op die invloed van gas- en vloeistof vloeitempos en plaat geometrie op meesleuring vir die lug/water sisteem. Gevolglik is die nie-lug/water databasis klein en bestaan van die data wat verkry is uit verskeie plaat en kolom-geometrieë. As gevolg is die akkuraatheid van die huidige meesleuring voorspelling modelle vir stelsels anders as lug/water te betwyfel. Daarom is die eerste doel van hierdie werk om ondersoek in te stel of die huidige voorspelling modelle goed presteer vir stelsels anders as lug/water. Om dit te bewys was lug/water, lug/etileenglikol en lug/silikon olie data gemeet en vergelyk met die huidige voorspelling korrelasies. Daar is bevind dat die huidige voorspellings modelle swak presteer vir die lug/etileenglikol en lug/silikon olie. Op dieselfde tyd was 'n nuwe waarneming gemaak met betrekking tot dispersie ontwikkeling en gedrag binne die kolom. Die waarneming toon dat vloeistof vloeitempo 'n nie-monotoniese invloed op meesleuring het, veroorsaak deur die kort (475mm) plaat vloei pad lengte. Die tweede doelwit was om die invloed van gas fisiese eienskappe op meesleuring te ondersoek. Nuwe meesleuring data was gemeet deur individuele kontak van lug, CO2 en SF6 met water en etileenglikol, terwyl n-butanol slegs met CO2 en SF6 inkontak gebring was. Die eksperimentele resultate word vergelyk met die huidige voorspellings modelle wat swak presteer invergelyking met SF6 resultate. Dit toon die onvermoë van hierdie modelle om meesleuring vir gas stelsels met hoë digthede te voorspel. Gemodifiseerde Reynolds en Froude getalle was ontwikkel om die invloed van gas fisiese eienskappe op meesleuring aan te toon. Lae gemodifiseerde Reynolds getalle en groot gemodifiseerde Froude getalle lei na hoë meesleuring. Die derde doelwit was om die invloed van vloeistof fisiese eienskappe op meesleuring te bepaal. Nuwe meesleuring data is gemeet deur gebruik te maak van CO2 met Isopar G, nbutanol, water, silikon olie en etileenglikol. Huidige voorspellings modelle vergelyk swak met die data en sluit nie die invloed van vloeistof viskositeit op meesleuring in nie. Daar is gevind dat viskositeit 'n ingewikkelde nie-monotoniese invloed op meesleuring het. Die vierde en finale doelwit was om die invloed van die gas en vloeistof eienskappe op meesleuring soos bepaal deur die vorige twee doelwitte te korreleer. Om die datastel meer volledig te maak, is meesleuring vir vier plaat spasiërings met CO2/Isopar, CO2/n-butanol, lug/etileenglikol, CO2/ethylene glycol, lug/silikon olie en CO2/silikon olie (meer as 1700 data punte gemeet). Twee nuwe korrelasies word aangebied om die fraksie vloeistof wat meegesleur word met die stygende gas (L’/G met R2 = 85%) en die fraksie vloeistof wat die plaat binnetree wat meegesleur word (L’/L met R2 = 92%) te voorspel. Die prestasie van die L’/G korrelasie (R2 = 85%) is aansienlik beter as twee ander prominente korrelasies (R2 = 61% en 23%). Hierdie korrelasie kan suksesvol geïmplementeer word om meesleuring vir verskillende plaat geometrieë te voorspel deur die voorspelde invloed van plaat geometrie deur Kister en Haas (1988), met die resultate van die nuut ontwikkelde korrelasie te kombineer. Al vier doelwitte word as manuskripte vir joernaal publikasie aangebied en dien as alleenstaande dokumente.

In this thesis, theoretical investigation of nickel-like tin plasma is presented. X-ray production in a plasma medium produced by a laser beam is reviewed. Applications mostly, lithography are discussed. Two different schemes for x-ray lasing, namely, quasi-steady state and transient collisional excitation are explained and compared. The computer codes that are used for plasma, especially for laser produced plasma and x-ray laser including hydrodynamic codes, ray-trace codes and collisional radiative codes are discussed. The code used in this work, EHYBRID, is considered in more detail. An experimental setup which can allow x-ray lasing is designed for different plasma and laser parameters are analyzed by means of EHYBRID code. Results are briefly discussed and as a future work the realization of the related experiment is mentioned.

The non-uniform dc glow discharge plasma system is studied by using isolated computer controlled three couples of double probe system (TCDP) in argon gas, simultaneously. TCDP system has been developed to use for magnetized, unmagnetized, and for low oscillating plasma systems by using low pass filter with optically isolated circuitry to minimize the measurement errors with higher resolution and accuracy. Difference in the shapes and diameters of the discharge tube from region to region leads to change in the positive column glow discharge properties. This is because the positive column inhomogeneities, rising from the increase in the electron densities at the small tube radius region than the large one. Therefore, the axial electric field and the electron temperature have been diverted from their normal behavior in the positive column. However, at the large radius regions, the axial electric field seams to stay approximately constant at higher discharge currents. On the other hand, In this work the radial dependence of the electron temperature, density, floating potential, and the normalized probe radius (&amp / #958 / =rp&amp / #955 / D) has been investigated. Since, the probe radius is smaller than Debye length, the orbital motion limited (OML) theory has been used. As a result, the electron temperature (at the center) decreased and density increased with decreasing tube radius, and they have maximum values at the first probe (near the cathode). The electron density ne was observed to decrease and electron temperature Te to increase with increasing the discharge current. The floating potential has less negative value with decreasing tube radius except at the higher currents. Finally, it has been found that the &amp / #958 / is proportional with electron density, but it remains constant depending on the value of Te and ne.

From early colonial times the Canadian economy, highly dependent on exports, has developed a pluralist economic system in a generally congenial international environment. Since 1970 however, the Canadian economy has been challenged, albeit at the margins, by unfamiliar impacts largely originating in the Pacific economy. The institutional reactions of relevant Canadian export interests - defined as the federal government, provincial governments and a small number of Canadian firms - have, on the whole, proved inadequate to these challenges. This inadequacy threatens Canadian domestic prosperity and constrains economic and political options internationally. This study hypothesizes that an adequate response to these new challenges depends on institutional adaptation within and among Canadian export interests. Six principles are advanced to promote this adaptation: 1. the priority of economic considerations; 2. the legitimate role of government; 3. full provincial participation; 4. coordination by the national government; 5. an authoritative voice for each interest; 6. better sharing and use of information. The six principles are applied in three case studies. The first concerns the international marketing challenge posed by the Japanese general trading company (soga shosha), and the Canadian government's initiative to create a Canadian trading corporation. The application of the six principles suggests an alternative proposal, the Canadian Commercial Centre, in which Canadian export interests develop and share information in a way which recognizes the appropriate role of each and the obligation of all to attain a greater coherence. The second case study concerns the recent Western Liquid Natural Gas (WLNG) project which featured a new form of investment (the minority interest joint venture coupled with a long-term supply contract) in which a consortium of Japanese buyers represented by a Japanese general trading company sought to reach agreement with an uncoordinated collection of Canadian firms and governments. The lack of coherence among these Canadian interests was at least a contributing factor in the loss of an opportunity to expand and diversify Canadian LNG markets. The application of the six principles to the WLNG case yields an alternative Canadian approach involving the early establishment of a committee of authoritative officials from the relevant Canadian interests, and a new coordinating role for a federal agency like the (now disbanded) Ministry of State for Economic and Regional Development and the Federal Economic Development Coordinator. The final case study concerns the challenge to trade and investment represented by the movement to a Pacific economic community, notably the Pacific Economic Community concept (PECC). The current reactions of such institutions as the Canadian committee of the Pacific Basin Economic Council and the federal Department of External Affairs are assessed, leading to the recommendation that the Canadian government should involve a wider constituency of current and potential Canadian export interests in an educational policy process which may bear on Canada's future prosperity and political resilience. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

This thesis is focused on the design of steam boiler like a supplement for cogeneration unit of biogas plant. The main idea is to use a waste heat from the exhaust gasses to produce a technological steam of required parameters. The thesis contains of a calculation an amount of the heat in exhaust gasses and a heat exchange surface. An Aerodynamic loss and a wall thickness of the boilers are verified by strength calculation in the next parts of this thesis. At the end of this thesis are made projection drawings and diagram, which are made of the calculations.

The industry sector accounts for a vast amount of the world’s total energy use, as much as 37% during 2018. Using energy in a sustainable way is necessary from both an environmental and an economical perspective, and it is therefore relevant to take measurements that result in a more efficient use of energy. One way for industries to become more energy efficient is to recover the waste heat, which is energy that otherwise would go to waste. This report aims to find a method to recover and reuse the low temperature waste heat available at the life science company Cytiva’s production site in Uppsala, Sweden. The proposed solution will be to use the waste heat for heating a vertical greenhouse. The study will examine whether this is feasible, and also how installing photovoltaics affects the energy use. Furthermore, the environmental impact of operating the greenhouse with waste heat is also investigated by calculating the CO2 equivalent. The low temperature waste heat that Cytiva provides relevant for this study is 6683 kW, which will be used to heat up the greenhouse. Simulations in the software IDA ICE will be used to construct and simulate a model of the vertical greenhouse. Results from the simulations show that the chosen size, 25 x 50 x 35.5 meters, gives a good approximation according to the wanted temperature range, 18.3-32.2°C. Furthermore, the results imply that the total energy use, 790 652 kWh, and average power, 90.26 kW is less than the available waste heat and there is a large amount that still is unused. The CO2 equivalent is calculated to be 29 317 kg. A sensitivity analysis is made to evaluate the window-to-wall ratio as well as the size of the entire greenhouse. It showed that both parameters are critical and makes a big difference in the simulations.

The electrodeless plasma discharge is typically driven by radio frequency (RF) power supply within the range (0.2 &iexcl / 40 MHz). The applied power is coupled into the plasma inductively called inductively coupled plasma (ICP). RF ICP technique has achieved significance importance in a diversity of research and industrial applications for over the last threes decades. It is still required to undertake both theoretical and experimental research. In this work, RF ICP technique is applied on the torch modeling in 2D. Based on extended electromagnetic vector potential representation, an axisymmetric model in 2D is proposed for the calculations of the electromagnetic fields in an RF ICP torch. The influence of axial vector potential is included to the vector potential formulations. This is achieved by imposing a helical current carrying wire configuration. The corresponding governing equations are solved numerically by applying finite element method (FEM) using commercial partial differential equation solver (Flex PDE3). Based on this model, the plasma behavior and properties are examined in terms of plasma parameters. Besides, a comparative iii analysis is made between proposed model called helical configuration and the one currently available in the literature called circular configuration. This study shows relatively little difference between temperature fields predicted by two models. However, significant difference is observed between corresponding flows and electromagnetic fields. Especially, tangential flow which is observed in helical configuration vanishes in circular configuration. The proposed model offers an effective means of accounting for the variations of the helical coil geometry on the flow and temperature fields and achieving a better representation of the electromagnetic fields in the discharge. Finally, it is concluded that minimum number of turns (n = 2) yields significant difference between two models whereas, maximum allowable number of turns yield no distinctions on the results of two models in terms of azimuthally applied current. However, axial effect of current still exists but very small with respect to the result obtained with minimum number of turns.

This theses fokus on the enviromental impact of livestock raising cycle (cattle, pigs and poultry). Energetical costs and emissions caused by livestock fattening are counted including processing and transport of the final product ? meat. Conventional and organic farming were compared as well as different forms of housing. SIMA Pro software tool was used for obtaining the emission load. The aim of the work was to find which form of livestock raising has the least environmental impact. This work was created in the European Union internatiponal project M00080-EUS-AT-SUKI Sustainable Kitchen focusing on the emission load of substantial links of vertical production chain.