This diploma thesis deals with the design of a robotic workplace for deburring of a given part. The robot's task is to remove the machined part from the production machine, create a blank workpiece ready for machining, and finally deburr the the machined part. There are several proposals for the layout of the robotic cell, as well as the design of the end effector, the input tray for semi-finished products and a stand with tools for deburring. Subsequently, a simulation model of the designed robotic cell is created in the Siemens Process Simulate software. Using RSC modules, the exact resulting cell clock is determined. The whole process of creating a simulation model is detaily described. At the end of this thesis is an economic evaluation of the proposed solution.

The diploma thesis deals with the virtual commissioning of robotic workplace designed to engrave board materials and their subsequent packaging. The summary of the knowledge that contributes to the development of the virtual commissioning as well as description of each component of the given robotic cell, are described in the theoretical part. In the practical part are described procedures such as assembling of the simulation model in Process Simulate software, creating the PLC program in integrated development environment TIA Portal or creating visualization for HMI panel. In the end, the actual commissioning of the workplace was performed, followed by additional modification and validation of the robotic program.

The main goal of this master’s thesis is to create a design of robotic cell for operating of blasting machine. Operation of blasting machine consists of robotic manipulation of aluminium castings from input container to the blasting machine conveyor. After blasting operation aluminium castings are manipulated by robot from conveyor to output container. The part of the master's thesis is proposal of several variants of solution of design of robotic cell. Afterwards the best option is selected. The thesis also deals with design and selection of functional components in robotic cell. Functional verification of robotic cell is made in software Tecnomatix Process Simulate. Technical-economics evaluation is also part of this master’s thesis.

Polarization mode dispersion, PMD influence of fibres. Next includes optic dispersion measurement and compensation of optics dispersion follows. In the end thesis analyze measure of existing fibres, simulating and suggest optimal solutions.

This master’s thesis deals with problems of analog differential converters, which are used in measuring circuits working in the current mode. The aim of this thesis is to propose a new voltage to current and current to voltage converter, that should influence measured frequency properties as little as possible. Commercial active elements are use to design converters. Active components are compared on the basis of properties as bandwidth and slew rate. Designed converters are simulated in Orcad PSpice program. Converters, of the best behavior are practically implemented and measured. Measured and simulated values are compared.

In this paper, four methods to simulate or generate electric resistance at high resolution have been developed, tested and evaluated. Each method is called a Resistor Simulator and are numbered from one to four.  Resistor Simulator one is based upon a set of digital potentiometers configured to achieve increased performance over a single 8-bit potentiometer. There were many issues with calibration and control over the individual potentiometers leading to a decent but uneven characteristic.  Resistor Simulator two tests the setup of an encapsulated LED a photoresistor pair where output resistance is controlled by the light output of the current controlled LED. Although the output was purely resistive, and the resistance was controllable. This method has big issues with non-linearity and very poor repetitivity were the same input could give resistances several kiloOhms apart.  Resistor Simulator three uses an ADC in combination with a DAC to measure the current going through the simulator over a shunt-resistor and regulate the voltage output to match the voltage-drop that the set resistance would generate. There were some issues with working in the extreme ends of the analog electronics in the circuit limiting how low currents that could be properly measured. This problem could be bypassed to evaluate the rest of the system with good results. The limiting factor of the simulator was the resolution of the DAC at high resistances. Resistor Simulator four was the largest and costliest of them all, but performance was also the best. It is built as a resistance ladder with a set of 16 binary matched resistors and bypass switches for each resistance. This way, output resistance is set just like a binary number. The performance of the simulator was equally good throughout the entire resistance span. The only thing that limited performance from great to good was that it was hard to get precisely matched resistors of odd values and low tolerance making for some deviation from the theoretical resistances. All four resistance simulators were realized on a single Arduino shield PCB, designed with Altium Designer and assembled by the student. Although an Arduino was used for this project, any microcontroller could be used as all communication with the PCB is done via SPI.  Resistance performance was evaluated with an automated test system for inaccuracy, resolution and repetitivity. Furthermore, practicality parameters such as size and cost were evaluated to further determine the suitability of each resistor simulator.  The outcome from this work is intended to be used as basis to design systems for test and evaluation of alarm systems. / Denna rapport beskriver fyra metoder för att simulera eller generera elektisk resistans med hög upplösning och noggrannhet. Metoderna har identifierats, utvecklats, testats och utvärderats. Varje metod benämns som en Resistor Simulator och är numrerade från ett till fyra. Resistor Simulator ett bygger på en uppsättning av digitala potentiometrar konfigurerade i en krets för att utöka dess upplösning och prestanda jämfört med en enkel 8-bitars potentiometer. Dock så stöttes en hel del problem på i samband med kalibrering och styrning av de individuella potentiometrarna med hyffsad men ojämn karaktäristik. Resistor Simulator två utvärderar konceptet med en inkapslad LED och fotoresistor där resistansen styrs genom att kontrollera ljusflödet med strömstyrning av dioden. Denna lösning var den enda med rent resistiv utgång och resistansen var kontrollerbar. Dock så har metoden stora problem med icke-linjärt beteende och variationer mellan test där samma styrsignal kan ge resistanser flera kiloOhm från varandra. Resistor Simulator tre använder en ADC tillsammans med en DAC för att mäta strömmen genom simulatorn och reglera spänningen för att motsvara det spänningsfall som den valda resistansen skulle generera. Denna lösning stötte på en del problem med för höga spänningsnivåer på den analoga elektronik som användes vilket begränsade hur låga strömmar som kunde mätas. Detta problem kunde förbigås för att utvärdera resten av systemet med goda resultat. Den begränsande faktorn för simulatorns upplösning låg dock i upplösningen på DAC vid höga resistanser. Resistor Simulator fyra var den största och dyraste av dem alla, men också den som presterade bäst. Den är byggd som en resistorstege med en uppsättning av 16 binärt matchade resistorer som alla försetts med en kortslutande styrbar brytare vilket gör att resistans kan beräknas på samma sätt som ett binärtal räknas. Prestandan var genomgående bra i hela mätområdet med enda baksida att det var svårt att införskaffa resistorer av udda värden med mycket låga toleranser varav mindre avvikelser från den teoretiska upplösningen uppkom. Alla simulatorer realiserades på ett tilläggskort till en Arduino som designats med Altium Designer och byggdes ihop av studenten. Även om en Arduino användes för just detta projekt skulle vilken annan mikrokontroller kunna användas då all kommunikation på kretskortet sker via SPI. Prestandan av simulerad resistans testades med ett automatiskt testsystem och utvärderades för onoggrannhet, upplösning och repeterbarhet. Utöver detta utvärderades praktiska parametrar som storlek och materialkostnad för att kunna utvärdera i vilka sammanhang respektive simulator passar bäst till. Utfallet från detta arbete avser att ligga till grund för utveckling av utrustning för test och utvärdering av larmsystem.

MSCAGR (Soil Science) / Department of Soil Science / Maize (Zea mays L.) is widely grown in the semi-arid regions of South Africa mainly for its grain that is used for direct human consumption, feed for animals and raw materials for the industries. The challenges of soil infertility, water supply, and availability of high yielding cultivars remain a major constraint for its production in this environment. These constraints are a major threat to sustainable crop production and food security. Maize/lablab Zea mays L.\ L. purpureus) intercropping system could thus become an option for food security among small scale maize producers in dry environments. Preliminary studies show the huge potential of maize/lablab intercropping in the semi-arid environments of the North-Eastern South Africa. Therefore, this study aimed to assess the effects of maize/lablab intercropping on soil water content, nitrogen dynamics and crop productivity based field experiments and crop simulation modeling using the model APSIM. The trials were conducted at two sites (Univen and Syferkuil) in Limpopo province, South Africa, for two seasons (2015/2016) and 2016/2017). The treatments consisted of; (i) sole maize (ii) sole lablab (iii) maize and lablab planted at the same time (Maize+lablab-ST) and (iv) maize with lablab planted 28 days after maize (Maize+lablab-28).The treatments were laid out in an RCBD replicated 4 times, with individual plots size measuring 4.5 m × 4 m (18 m2) and the layout of the field as consisting of 4 plots per block giving a total of 16 plots in 4 blocks. The following parameters were determined: soil water content, soil NO3--N and NH4+-N levels, dry matter and grain yield. The APSIM-model (version 7.7) was then used to simulate maize grain yield and dry matter production to assess risks associated with the production of maize/lablab intercropping. The results obtained from this study showed that maize/lablab intercropping had significant effects on measured parameters (grain, biomass yield soil water content, and N-minerals). Maize+lablab-28 produced 46 % higher grain yield than sole cropping (24%) and maize+lablab-ST) (30%). The results also showed variation in soil water content at different depths among the treatments. The soil water content was increased with depth. The intercropped plots and lablab sole had significantly higher soil water content than the sole maize. At all depths, the highest soil water content was obtained under sole lablab followed by maize+lablab-ST and maize+lablab-28. It was notable however that maize/lablab intercropping showed a higher NO3--N and NH4+-N levels at all depths. At both sites, the soil NO3--N showed a sharp drop at V7 sampling time. The results showed the benefits of intercropping in comparison to sole cropping as demonstrated by positive land equivalent ratios of >1 for both cropping systems in both years and sites. Modelling exercises showed that APSIM was able to simulate the results sufficiently. In the simulation experiment, a stronger negative effect of planting lablab with maize simultaneously was found. Hence, delayed planting of lablab should be a standard practice / NRF

In recent years, the enthalpy raise hot channel factor limit has decreased significantly due to the power upgrade of Ringhals 4 and the use of shielding fuel assemblies. The shielding fuel assemblies task are to reduce the neutron leakage to the reactor vessel and in that way extend the reactor lifetime. This is achieved by replacing a few fuel rods with steel rods. Experiences from the last fuel cycles show that the core design procedure has been hampered because of this and that it’s hard to stay under the design limit. A way to overcome this problem and to improve the fuel economy is to introduce the use of radial enrichment distribution in the fuel assembly. This master thesis shows, through a case study of three fuel cycles at Ringhals 4,  that the internal peaking factor can be improved by roughly 2–3 % and that the maximum enthalpy raise hot channel factor can be improved by about 2.0–2.5 % if the fuel assemblies contain three different levels of enrichments instead of currently one. This can be achieved without any noticeable decrease in cycle length. / Genom en fallstudie av tre driftcykler för Ringhals 4 visar den här rapporten att max FΔH under cykeln kan sänkas med 2,0–2,5 % om bränsleknippena radiellt anrikningsoptimeras med minst tre delanrikningar. Totalt under cykeln kan FΔH sänkas med upp till 4 %. Om radiell anrikningsoptimering införs för Vattenfalls PWR:er skulle arbetet med att designa härdarna förenklas och utrymme ges för att ladda reaktorerna på ett mer ekonomiskt sätt.

Die Präsentation stellt kurz die Grundlagen der Berechnung von Schraubenverbindungen in Anlehnung an die VDI-Richtlinie 2230 Teil 1 dar. Auch die vier FEM-Modellklassen, die die VDI 2230 Teil 2 (Entwurf) zur Berechnung von Mehrschraubenverbindungen vorschlägt, werden behandelt, und die in Creo Simulate vorhandenen Softwarefeatures zu deren Umsetzung vorgestellt. Es folgt eine Darstellung, was bei der Linearisierung von Schraubenverbindungen zur vereinfachten Berechnung zu beachten ist, und wieso bei der Berechnung im FEM-System dann nicht notwendigerweise eine Vorspannung benötigt wird. Ausführlich wird das neue Schraubenfeature in Creo Simulate betrachtet, das eine weitgehend automatisierte Modellierung und Berechnung von Standardverschraubungen erlaubt. Weitere Features, wie die neuen Vorspannelemente, werden erläutert, sowie auch die Grenzen der Software aufgezeigt. Abschließend werden zwei anspruchsvolle Anwendungsbeispiele vorgestellt: Eine zentrisch belastete Verschraubung mit Berücksichtigung von Elasto-Plastizität und einer komplexen Lasthistorie (Anziehen durch Anzugsmoment, Setzeffekte, Entfall des Torsionsmomentes durch das Anziehen, Betriebskraft) sowie eine exzentrisch belastete Verschraubung, die wegen eines relativ dünnen Flansches starke Biegezusatzbeanspruchungen erfährt. / The presentation shows the foundations of bolt analysis according to VDI-guideline 2230 part 1. In addition, the four FEM model classes proposed in VDI 2230 part 2 (draft) are described, as well as the features available in Creo Simulate to realize these model classes. Next, the presentation shows the requirements for linearizing bolted connections, and why in a FEM analysis with a linearized connection no preload is necessary. The new fastener feature introduced in Creo Simulate is explained in detail. This feature allows the automated modeling and analysis of bolted connections having standard geometry. Further software features, like pretension elements, as well as the current software limitations are shown. Finally, two advanced application examples are shown: A centrically loaded bolted connection taking into account elasto-plasticity and a complex load history (tightening torque, embedding, removal of tightening stress, operational load), and an eccentrically loaded flange connection, which is subjected to high additional bending loads because the flange is relatively thin.

Der Vortrag beschreibt, wie mittels des Kontaktmodells mit endlicher Reibung in Creo Simulate 3.0 ein Schwungrad mit axial verschraubtem mit Kegel-Presssitz berechnet werden kann. Da in Creo Simulate 3.0 des Softwareentwicklers PTC das Kontaktmodell mit endlicher Reibung nur für die Theorie großer Verformungen implementiert ist, nicht jedoch für einfache Analysen mit kleinen Deformationen, muss der Anwender einige softwareseitige Einschränkungen geschickt umgehen. Es werden Vorgehensweisen vorgeschlagen, wie der Anwender dies bewerkstelligen kann. Ein besonderer Schwerpunkt liegt dabei auf der Modellierung von Schrauben sowie der Einstellung der Schraubenvorspannung. Rechenergebnisse des Programms werden mit analytischen Lösungen verglichen. / The presentation describes how to analyze a flywheel with axially bolted hub-shaft- connection using a conical press fit with help of the finite friction contact model in Creo Simulate 3.0. Since Creo Simulate 3.0 from PTC offers a finite friction contact model implementation just for large displacement analysis, but not for simple analyses with small displacements, the user has to work around a couple of code specific limitations. Best practices are proposed how to do this. Special attention is paid on bolt modeling and preload adjustment. Analysis results are compared with analytical solutions.