This thesis is focused on proposing a design and providing the realisation of a CNC drill used for printed circuits. The first section is concerned with researching the background of CNC drills, which is followed by the proposed design and realisation of a custom model. Fundamental calculations and individual constructional aspects were carried out based on the chosen parameters. Furthermore, the operating electronic functions and the description of a G-code generating program is the main content of the second section. Finally, the last part of this thesis includes economic evaluation and the CNC drill’s assessment in practice.

This diploma thesis serves as experimental proof of real world capabilities of computer designed hobby CNC milling machine with its parts printed on a 3D printer. First half is a brief introduction of CNC technologies to non-professional audience. Second part together with 3D model works as manual to build your own machine. Priority was to keep costs to minimum with decent accuracy still in mind.

It is important to consider broader context to create a concept for a chateau complex in Breclav - within the region and mainly engaging in Lednice-Valtice Cultural Landscape (LVA). Buildings of LVA are a heritage of Lichtenstein as well as the chateau complex in Breclav. Breclav is also referred to as the gateway to the Lednice-Valtice area. Lednice-Valtice area has been from its beginning a place for recreation and entertainment and that is the concept of what it should be nowadays. Partly the buildings of LVA are used for various cultural events - concerts (Lednice), educational programs (Pohansko) and exhibitions (Valtice). However there are mostly only tours of the interiors and only seasonally. To fulfil the potential of the area it would be appropriate to join all of the buildings in one program that will support the current events and complement with other functions. I propose to use the chateau complex in Breclav as a cultural and recreational centre with outreach to the LVA. Breclav would complete the triangle with other centres in Lednice and Valtice.

Nitrogen is required by plants in large quantities and its deficiency is mostly related to reduction in crop production. A study was conducted to assess the importance of nitrogen in tomato (Lycopersicon esculentum Mill.) transplant production. Transplants were propagated at 0, 30, 60, 90, and 120 mg∙L-1 N applied as NH4NO3 while 30 mg∙L-1 P applied as NaH2PO4 and 30 mg∙L-1 K as KCl were used. Fergitation was done by floating cavity trays in nutrient solution until the medium reached field capacity. The experiment was arranged in a randomized complete block design (RCBD) with four replications. Sampling was initiated at 21 days after sowing and was done weekly until the transplants were ready for transplanting (when transplants could be pulled out of the cavity easily without breaking) at 42 days after sowing. Nitrogen supply had a pronounce influence on the transplant root and shoot growth. Observations throughout the experiment indicated that increased nitrogen application favoured shoot growth which is an indication that most of the assimilates were partitioned to shoots rather than to roots. Nitrogen application of 120 mg∙L-1increased fresh shoot mass and subsequently enhanced dry shoot mass. As nitrogen was increased from 0 to 120 mg∙L-1, it further promoted relative growth rate, specific leaf area, leaf mass ratio, leaf area ratio, plant chlorophyll content, leaf tissue nitrogen and improved the pulling success. At 42 days after sowing, a quality transplant that was produced with 90 mg∙L-1 N, had a root to shoot ratio of 0.16, leaf mass ratio of 0.86, root mass ratio of 0.13, leaf area of 594 cm2, plant chlorophyll content of 33, leaf tissue nitrogen of 32 g∙kg-1, specific leaf area of 194 cm2∙mg-1, leaf area ratio of 167.7 cm2∙mg-1, relative growth ratio of 0.31 cm∙mg-1∙wk-1 and 100% pulling success. This transplant proved to be ideal for the production of tomato as compared to other treatment combinations that were employed. Another glasshouse experiment was conducted to determine the influence of electrical conductivity (EC) and or nutrient solution composition on growth, yield and quality parameters in tomato. The pots were arranged in a randomized complete block design (RCBD). One plant per pot represented an experimental unit. Four EC treatments were used that consisted of 1.12, 2.24, 4.48 and 6.72 mS∙cm-1. Each treatment was replicated six times. Distilled water was used for irrigation water to maintain the required pH, which was 5.5 to 6.2 throughout the duration of the study, and cocopeat was used as substrate. Salinity inhibited growth (shoot length) and yield (average fruit mass, fruit diameter and fruit circumference) at the highest concentration of 6.72 mS∙cm-1. However, it did not significantly affect number of trusses, number of fruits and stem diameter, rather tomato quality was improved in terms of total soluble solids. Although tomato fruits grown at 6.72 mS∙cm-1 were relatively smaller than fruits grown at 1.12, 2.24 and 4.48 mS∙cm-1 treatments respectively, they had higher acidity, increased soluble solids and higher sugar content which are all qualities required by the tomato processing industry. Increasing the concentration of the solution from 1.12 to 6.72 mS∙cm-1 increased the %Brix from 3.9 to 6.1% while titratable acidity was also increased from 3.3 to 5.7%, respectively. The incidents of blossom end rot were higher (6.3%) at concentration of 6.72 mS∙cm-1 as compared to 1.12 mS∙cm-1 concentration, which was 0.5%. / Dissertation (MScAgric)--University of Pretoria, 2014. / tm2015 / Plant Production and Soil Science / MScAgric / Unrestricted

This study examines the wastewater treatment system on BillerudKorsnäs integrated pulpand paper mill at Karlsborg, with focus on the effluent of suspended solids. Due to lowerregulatory limits for the emissions of suspended solids BillerudKorsnäs is looking forways to improve the efficiency of the wastewater treatment. Therefore, this study seeksto create a statistical model for the emissions of suspended solids and to find which factorsin the production, wastewater treatment and surrounding environment that affects theemissions. The purpose of the study is to extend the current understanding of the treatmentsystem to create a base for future decisions. The methods used for the modelling areElastic net regression and Random forest classifier, which were selected for the variableselection properties they provide. Unfortunately, the results show that the fitted modelscan only explain a small part of the variation of the emissions of suspended solids.The lack of fit in the models indicate that the current data is not sufficient to explain thevariation in the emissions of suspended solids. During the study deficiencies in the datacollection has been detected and improvements to overcome these deficiencies are proposedin the hope of creating more reliable data for the company and to create a betterbasis for future studies. / Denna studie undersöker avloppsvattenreningen på BillerudKorsnäs integrerade massaoch pappersbruket i Karlsborg, med fokus på utsläppen av suspenderade ämnen. Pågrund ut av sänkta gränser för utsläppen av suspenderade ämnen undersöker BillerudKorsnäsmöjligheter för att öka effektiviteten i avloppsvattenreningen. Därför försöker dennastudie att skapa en statistisk modell för utsläppen av suspenderade ämnen och undersökavilka faktorer i produktion, avloppsvattenrening, och omgivande miljö som påverkar utsläppen.Syftet med studien är att förbättra förståelsen för avloppsvattenreningen och attskapa beslutsunderlag för framtida förbättringar. Metoderna som används i modellernaär Elastic net regression och Random forest classifier, vilka valdes för deras variabel selectionegenskaper. Resultaten för modellerna visar att modellerna endast kan förklara enliten del av variationen i utsläpp av suspenderade ämnen. Det dåliga resultatet indikeraratt nuvarande data inte är tillräckligt för att skapa den typ av modeller som används. Understudien så har brister i datainsamlingen upptäckts, och förbättringar för att överbryggadessa brister är föreslagna med ändamål att göra insamlad data mer pålitlig och skapa enbättre bas för framtida studier.

Premature and excessive leaf abscission during flowering time in the late avocado (Persea americana Mill.) cultivar ‘Ryan’ is a considerable problem for avocado growers. They are especially concerned that premature and excessive leaf abscission will have a negative effect on yield. No previous investigations have been performed where premature and excessive leaf abscission in avocado has been studied in detail. This study therefore aimed to investigate the pattern of premature and excessive leaf abscission in ‘Ryan’, and compare it with two other important commercial cultivars, ‘Fuerte’ and ‘Hass’, which do not display this phenomenon. Time course studies of leaf abscission in the orchard were performed during 2006 and 2007 to determine the pattern of leaf abscission on ‘Ryan’, Fuerte’ and ‘Hass’. This also included anatomical studies to determine the time of leaf abscission zone formation. Possible stress factors, which accelerate leaf abscission were also investigated, namely unfavourable climatic conditions (temperature, solar radiation, rainfall, relative humidity and evapotranspiration), nutrient imbalances, excessive flowering and leaf area. The possible impact leaf abscission may have on yield was then assessed by determining levels of reserve carbohydrates in the bark of the tree. In addition, practical solutions, i.e. the application of fertilizers, plant growth regulators (PGRs) and kaolin, were investigated in order to reduce or eliminate premature and excessive leaf abscission. This study was carried out over the period 2005 until 2007, with experiments being modified on an annual basis as information was gathered on the phenomenon. Experiments began in 2005 with a study on the pattern of leaf abscission in ‘Ryan’, which revealed an increase in leaf abscission just prior to flowering. However, this increase was not significant. During 2006, the leaf abscission pattern for ‘Ryan’ was compared with the leaf abscission patterns of ‘Fuerte’ and ‘Hass’. Leaf abscission for ‘Ryan’ was significantly higher than for ‘Fuerte’ and ‘Hass’ during 2006. During 2006 ‘Ryan’ displayed two periods of high leaf abscission, namely the spring flush between bud dormancy and bud swell, and a drastic increase in spring and summer flush leaf abscission between inflorescence development and full bloom. These periods of increased leaf abscission were absent during the 2007 season. In addition, ‘Fuerte’ and ‘Hass’ did not display these peaks of high leaf abscission, with leaf abscission occurring in these cultivars at higher rates from full bloom onwards. Premature and excessive leaf abscission is therefore not an annual event in ‘Ryan’ and is in all likelihood influenced by external factors. Anatomical studies did not reveal any results in terms of initiation of leaf abscission, with only the protective layer of the abscission zone being visible after leaf yellowing occurred. During 2006, two peaks of extremely low temperatures (<4°C) occurred just prior to the acceleration of leaf abscission. During the second period of low temperatures, the solar radiation:temperature-ratio was also considerably higher. These periods of low temperatures were absent during 2007, indicating that cold and light stress could be contributing to premature and excessive leaf abscission in ‘Ryan’ in 2006. In addition, ‘Ryan’ flowered excessively during 2006, which could have been triggered by low temperature stress just prior to flower initiation. A significant correlation was found between excessive flowering and excessive leaf abscission in ‘Ryan’ during 2006. The occurrence of reduced flowering in ‘Fuerte’ and ‘Hass’ may possibly be due to these two cultivars being more tolerant to stress, and it is possible that ‘Ryan’ is genetically more prone to excessive flowering than ‘Fuerte’ and ‘Hass’. Excessive flowering could accelerate leaf abscission by causing an unusually high demand for water, nutrients and carbohydrates, resulting in the acceleration of leaf abscission. No significant relationship between nutrient levels and excessive leaf abscission was found for either 2006 or 2007. In addition, no significant correlation could be found between leaf abscission on a branch and the total leaf area of that branch during the 2007 season. During 2007, leaf abscission was low and it is possible that a significant correlation could be found in a season with excessive leaf abscission. During 2005, chemical applications to reduce leaf abscission did not yield any significant improvement in leaf retention. In fact, the 50 g/tree Solubor® and 50 g/tree Solubor® in combination with 2 kg/tree dolomitic lime had a significant negative effect on fruit set, possibly because too high concentrations were applied too close to fruit set. Chemical applications during 2006 were therefore made at bud dormancy and bud swell, as it was found that leaf abscission occurred before flowering time. However, no effect was observed on leaf retention or fruit set. During 2007, emphasis was placed on treatments that might reduce stress, as it became evident that stress could be responsible for premature and excessive leaf abscission in ‘Ryan’. Most treatments showed a slight positive effect on leaf retention, but no significant results were obtained possibly because that particular season was a season of low leaf abscission. Further research on application of stress-reducing treatments is therefore recommended. Best farm management practices including optimal fertilization and irrigation is therefore vital to prevent stress, accelerating leaf abscission. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Plant Science / unrestricted

In this thesis I examine three models of justification for the epistemic authority of the principle of contradiction. Aristotle has deemed the principle "that the same attribute cannot at the same time belong and not belong to the same subject and in the same respect" the most certain and most prior of all principles, both in the order of nature and in the order of knowledge, and as such it is indemonstrable. The principle of contradiction is involved in any act of rational discourse, and to deny it would be to reduce ourselves to a vegetative state, being incapable of uttering anything with meaning. The way we reach the principle of contradiction is by intuitive grasping (epagoge) from the experience of the particulars, by recognizing the universals in the particulars encountered, and it is different from simple induction, which, in Mill's view, is the process through which we construct a general statement on the basis of a limited sample of observed particulars. Hence, the principle of contradiction, being a mere generalization from experience, through induction, loses its certainty and necessity. Even though it has a high degree of confirmation from experience, it is in principle possible to come across a counter-example which would refute it. Mill's account opens the path to the modern view of the principle of contradiction. In Principia Mathematica, Russell and Whitehead contend that the principle of contradiction is still a tautology, always true, but it is derived from other propositions, set forth as axioms. Its formulation, "~ (p & ~p)" is quite different from Aristotle's, and this is why we are faced with the bizarre situation of being able to derive the law of contradiction in a formal system which could not have been built without the very principle of which the law is an expression of. This is perhaps because the principle of contradiction, as a principle, has a much larger range of application and is consequently more fundamental than what we call today the law of contradiction, with its formal function.

Over the years, Utah has enjoyed the advantage of having natural agricultural resources that favor the production of livestock. Sheep and beef cattle do well on the desert and high mountain ranges that cover much of the state, Dairy cattle and wintering beef cattle use the alfalfa and native hay along with some corn silage that is grown in the irrigated valleys. Feed grains are grown in rotation with forage crops on irrigated land and also on dry land. Before 1950, the quantities of feed grains produced had been sufficient to meet the needs of dairy, range livestock and poultry. However, with the realization that Utah had a natural market position in relation to the coast markets, there developed an extensive poultry and livestock fattening business. Since that time Utah has been in the position of a feed grain deficit state. This has tended to raise the cost of feed grain by $10 to $12 per ton due to the transportation factor. Also, Utah's poultry industry relied partially upon feed wheat from northern Utah and southern Idaho, but with acreage allotments and price controls, the price of wheat increased to the point where it was no longer used as a poultry feed. As a consequence, poultry and egg producers also had to turn to importing more of their feed grains, which put them into a higher feed cost position along with the livestock feeder. In the past year, however, the price of feed wheat declined to the point where wheat was used extensively in livestock feed stuffs for the first time in years.

The objective of the research presented in this thesis was to study and optimize the transverse deck reinforcement for a skewed concrete bridge deck supported by Hybrid Composite Beams (HCB's).  An HCB consists of a Glass Fiber Reinforced Polymer outer shell, a concrete arch, and high strength seven wire steel strands running along the bottom to tie the ends of the concrete arch together.  The remaining space within the shell is filled with foam.  The concrete arch does not need to be cast until the beam is in place, making the HCB very light during shipping.  This lowers construction costs and time since more beams can be transported per truck and smaller cranes can be used.  HCB's are quite flexible, so AASHTO LRFD's design model for bridge decks, as a one-way slab continuous over rigid supports, might not apply well to the HCB's deck design. A skewed three HCB girder bridge with a reinforced concrete deck and end diaphragms was built in the laboratory at Virginia Tech.  Concentrated loads were applied at locations chosen to maximize the negative and positive moments in the deck in the transverse direction.  The tests revealed that the transverse reinforcement was more than adequate under service loads. An Abaqus model was created to further study the behavior of the bridge and to help create future design recommendations.  The model revealed that the HCB bridge was behaving more like a stiffened plate at the middle section of the bridge, indicating that the flexibility of the girders needed to be considered. / Master of Science

This thesis is an exploration of how small independent residential units added one at a time can offer old buildings and the cities they are in the opportunity to gradually grow and change – in a way that isn’t presented by the typical double-loaded corridor build-out. The first component of this exploration is a modular unit that can be brought into existing buildings and assembled in a flexible layout. This House acts as a ‘Core’ that provides basic shelter, warmth, and a place to sleep and prepare food; the density of this unit allows the surrounding square footage to be used for other activities: kids playing, welding a project, or setting up easels for painting. The second part of this exploration is a pattern-based approach to the interaction of these units within the building: given certain rules that govern arrangement what are some possible spatial outcomes?