Master of Science / Department of Grain Science and Industry / Praveen V. Vadlani / Synthesis of chemical derivatives from finite fossil fuels requires considerable energy inputs and leaves an undesirable environmental footprint. The emerging biorefinery approach leads to sustainable processing of biomass into a wide spectrum of bio-based products, catering to food, feed, chemicals, materials, and bioenergy industries. Cyanophycin (multi-L-arginyl-poly-L-aspartic acid, CGP) is a non-ribosomally synthesized reserve polypeptide, which consists of equimolar amounts of arginine and aspartic acid arranged as a polyaspartate backbone and arginine as the side chain. Cyanophycin is a source of the constituent N-functionalized platform chemical, which can be further processed into many other chemicals of importance. It can be hydrolyzed in mild condition to its constituent amino acids - aspartic acid and arginine. These amino acids may be utilized directly in food and pharmaceutical applications. Based on the chemical structure of these amino acids and the presence of functionalized nitrogen-containing groups, it is conceivable that a number of industrial chemicals can be synthesized, for example: 1, 4-butanediamine， a co-monomer in the production of nylon-4, 6. Other chemicals which could be obtained from cyanophcyin, that are currently prepared from fossil resources, include 1,4-butanediol and urea. Cyanophycin can also be hydrolyzed to a derivative with reduced arginine content or even to poly-aspartic acid, and used as a biodegradable substitute for synthetic polyacrylate in various technical process, such as water treatment (water softeners) and plastics. Cyanophycin is produced by most cyanobacteria in nature; however, these microbes are not suitable for large-scale production due to slow growth and low polymer content. Biosynthesis of cyanophycin is catalyzed by a single enzyme - cyanophycin synthetase (CphA), which is encoded by cyanophycin synthetase structure gene (cphA). The cphA gene can be expressed in several bacteria and plants. E.coli is one of the most commonly used bacterial hosts for the production of recombinant proteins. The recombinant culture has the ability to produce considerably large quantities of cyanophycin in a shorter period of time compared to cyanobacteria. Genome of Anabaena variabilis ATCC 29413 has been sequenced, and it contains the structural gene (cphA) for cyanophycin synthetase. The native enzyme-cyanophycin synthetase from this cyanbacterium culture had been purified and it consists of identical subunits of 98kDa. Polymerization of the amino acids to cyanophycin in vitro is dependent on the presence of ATP, K+, Mg2+, a (cyanophycin) primer and a thiol reagent such as β-mercaptoethanol in the reaction mixture. Our research is the first time that cphA gene from A. variabilis ATCC 29413 was cloned into E.coli. The 2.7 kb cphA gene was amplified by PCR, ligated to the vector pET45b+ and cloned into BL21 (DE3) pLysS and BL21 (DE3). Characterization of cyanophycin was performed by SDS-PAGE, HPLC, mass spectrometry and amino acid analysis. Results showed that protein with molecular weight of 21.5 to 31 kDa did not match any E.coli proteins when compared with E.coli protein data base, thereby showing expression of a protein foreign to host strain. Amino acids analyses showed that the cyanophycin produced by recombinant E.coli contained aspartic acid and arginine, and small amount of lysine, in the ratio: 1.05: 1: 0.2 (mass basis), thereby confirming cyanophycin biosynthesis. Experiments for high cyanophycin synthesis was performed at shake flask and 2-L fermentor level using recombinant BL21 (DE3) pLysS, LB broth as carbon and nutrient source, and casamino acids as primer. The maximum yield of cyanophycin obtained in flask level was 7.6% of cell dry mass, and the yield increased to 12.6% of cell dry mass at 2-L fermentor level. Cyanophycin is also referred to as “structural granules” because of substructures visible in electron micrographs. Phase contrast photomicrograph was able to depict cyanophycin inclusions in the cytoplasm, and transmission electron microscopy depicted finer details inside cell after IPTG induction.

Master of Science / Department of Computing and Information Sciences / Eugene Vasserman / The Medical Device Coordination Framework (MDCF) is an open source Medical Application Platform (MAP) that facilitates interoperability between heterogeneous medical devices. The MDCF is designed to be an open test bed for the conceptual architecture described by the Integrated Clinical Environment (ICE) interoperability standard. In contrast to existing medical device connectivity features that only provide data logging and display capabilities, a MAP such as the MDCF also allows medical devices to be controlled by apps. MAPs are predicted to enable many improvements to health care, however they also create new risks to patient safety and privacy that need to be addressed. As a result, MAPs such as the MDCF and other ICE-like systems require the integration of security features. This thesis lays the groundwork for a comprehensive security architecture within the MDCF. Specifically, we address the need for access control, device certification, communication security, and device authentication. We begin by describing a system for ensuring the trustworthiness of medical devices connecting to the MDCF. To demonstrate trustworthiness of a device, we use a chain of cryptographic certificates which uniquely identify that device and may also serve as non- forgeable proof of regulatory approval, safety testing, or compliance testing. Next, we cover the creation and integration of a pluggable, flexible authentication system into the MDCF, and evaluate the performance of proof-of-concept device authentication providers. We also discuss the design and implementation of a communication security system in the MDCF, which enables the creation and use of communication security providers which can provide data confidentiality, integrity, and authenticity. We conclude this work by presenting the requirements and a high level design for a Role-Based Access Control (RBAC) system within the MDCF.

Inledning: Idag lever vi i en värld där interaktionen mellan företaget och slutkunden är oerhört stort, inte minst i spelindustrin som sedan tidigare har haft ett etablerat förhållande med sina kunder. Tack vare olika medier som sociala nätverk, bloggar och streamade videor så har detta förhållande blivit allt starkare. Problemformulering: Då spelindustrin har blivit en marknad där spelare och utvecklare allt mer jobbar tillsammans för att skapa värde för båda parter har det blivit allt viktigare att förstå hur mötet med spelarna på bästa sätt sker för att fånga deras upplevelser och de värde dem efterfrågar från spelen. Studien vill förstå hur denna process går till och klargöra en plattform som den fungerar som bäst på. Frågeställningar: Vilka plattformar finns det för spelutvecklare att interagera med sina spelare på? Hur fungerar dessa för att skapa värde samt en gemensam förståelse för både spelutvecklarna och spelarna? Kan dessa förbättras och hur? Metod: Studien har använt sig av en kvalitativ metod med en abduktiv ansats. Det har gjorts intervjuer och observationer för empiriinsamling. Studiens metod inkluderar även aktionsforskning. Slutsats: Studiens slutsats går kortfattat igenom vilka plattformar som finns idag och hur interaktion via dem går till och avslutas med ett konceptuellt plattformsförslag byggt på en diskussion kring förbättringar av nuvarande situation. / Introduction: Today we live in a world where the interaction between the company and the end customer is extremely large, especially in the gaming industry, which already have an established relationship with their customers. Thanks to various media such as social networks, blogs and streaming videos so this relationship has become stronger. Problem: As the game industry has become a market where players and developers are increasingly working together to create value for both parties, it has become increasingly important To understand how the meeting with the players in the best way happens to capture their experiences and the value they are demanding from the Games. The study wants to understand how this process works and find a platform that it works best on Framing of the question: What platforms is there for game developers to interact with their players? How do these work to create value and a common understanding for both game developers and players? Kan these be improved and how? Method: The study has used a qualitative approach with an abductive process. There have been interviews and observations of empirical data collection. The study's methodology also includes action research. Conclusion: The study's conclusion will briefly describe todays platforms and the interaction through them and ends with a conceptual platform proposal built on a discussion of improvements to the current situation.

The work performed in this thesis involves the study of human hip joint kinematics and load analysis. Such analyses are very useful for investigating mobility and natural functionality as well as the variation in motion due to replacement implants. The objective of this study is to design, build and testing of a universal human joint simulator that is configurable to hold several human joints and easily programmable to create the required motion. This was performed by creating a Stewart Platform, which is capable of moving in all six degrees of freedom; the maximum number needed by any human joint. Many specific human joint simulators are available on the market for simulating all major human limbs. These are used for wear testing replacement joints by using high load repetitive motion. These systems have a predetermined limit degree of movement and are very expensive; if one wanted to emulate another joint, one would have to purchase a whole new system. This novel system compromises of a three-phase power supply, Control Area Network with six actuators and drivers, a force reading clamp with strain gauges and data logger. A user friendly computer program was developed that is able to derive joint movement data from two inputs and replicating the movement by driving the platform, as well as recording force and displacement data from the joint. The product would be marketed towards biomechanical researchers and implant designers. Verification of this system was performed by simulating the human hip joint. A known combination of kinematic and force data were inputted into the system for nine different types of activities. The resultant force and joint centre displacement was then compared to see how well the system perform in comparison to the inputted data from a previous study. The outcome of this project is a fully functional machine and configurable program that can create movement data at varying speeds and body weights; which is also able to drive the human joint simulator. The design also costs a fraction of any industrial joint simulator. It is hoped that the simulator will allow easier study of both the kinematics and load analysis within the human joints, with the intent on aiding investigation into mobility and functionality; as well as variation in motion caused by a replacement implant.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper discusses the requirements and design of a multi-platform system software for control, status, calibration and testing of a telemetry system.

Thesis (MPhil (Document Design))--University of Stellenbosch, 2009. / This study focused on the image formation and projection of Helen Zille, leader of South Africa’s largest opposition party. South Africans are heading to voting stations in 2009 for the national and provincial election. For this reason the image a party portrays in all the methods it uses to attract voters needs to be perfect. Such methods include voting-posters, public debates and newsletters. This study focuses on the newsletters that Helen Zille writes every week and takes the form of a corpus analises. The study also shows the importance of the documentation from the leader of any institution. Such reasons include that the leader is the most identifiable person thereof. This study was undertaken within the framework of the Integrated Communication Model for Image formation and projection (IFP-model) developed by Professor Leon de Stadler. The model consists of three levels, namely the image, the information design and the document design. Each of these levels focuses on specific phases of image formation and projection. Image focuses on the intended (the desired image the institution want to construe) and the construed (the image the reader derives from the documentation) image. The information design involves the manner in which the reader accesses the text. There are three ways, which are the physical access (that which the reader sees first), the intellectual access (the way in which the information is interpreted) and the emotional access (how the reader feels about the content). The document design focuses on the four messages which appear in the text. They are the referential (the content), the appealing (the objectives), the expressive (the image of the sender) and the relational (the relationship between the reader and the sender) messages. This study focuses on the expressive and relational messages. Other questions mentioned in this study are whether the IFP-model kan be used as an analytical instrument and if this model kan be refined to place more emphasis on the expressive and relational messages. After the expressive and relational messages where identified, various tendencies where noticed in the content, style, structure and graphics thereof. These tendencies include a positive focus in the content, an informal style, high information density and the use of photographs as graphics. These tendencies where used to refine the IFP-model. The analises of the newsletters indicated that Helen Zille portrayed an image of a self-assured leader, but that this image was influenced by tendencies such as a negative focus on the ANC. Further findings showed that the IFPmodel can be used as an analytical instrument, but that more emphasis should be placed on refining the model so that it includes various aspects of the different levels, such as the different ways a reader gains access in the information design. This study also introduced a refined model which can be used to analyze the expressive and relation messages.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The successful development of a three degree of freedom motion simulation platform, capable of simulating a vessel’s flight deck at sea, is presented. The motion simulation platform was developed to practically simulate and test an unmanned aerial vehicle’s capability of landing on a moving vessel, before practically being demonstrated on an actual vessel. All aspects of the motion simulation platform’s development are considered, from the conceptual design to its practical implementation. The mechanical design and construction of a pneumatic motion simulation platform, as well as the electronics and software to enable the operation of this motion simulation platform, are presented. Mathematical models of the pneumatic process and platform orientation are developed. A controller architecture capable of regulating the pneumatic process, resulted in the successful control of the motion simulation platform. Practical motion simulation results of one of the South African Navy Patrol Corvettes, demonstrate the motion simulation platform’s success. The successful development of the motion simulation platform can largely be attributed to extensive research, planning and evaluation of the different development phases. / AFRIKAANSE OPSOMMING: In hierdie studie word die suksesvolle ontwikkeling van ’n drie-grade-van-vryheid bewegingsimulasieplatform, wat in staat is daartoe om ’n skip se vliegdek ter see te simuleer, aangebied. Die bewegingsimulasieplatform is ontwikkel om ’n onbemande lugvaartuig se vermoë om op ’n bewegende skip te land, te simuleer en te toets, voor dit op ’n werklike skip gedemonstreer word. Alle aspekte van die ontwikkeling van die bewegingsimulasieplatform word in ag geneem – van die konsepontwerp tot die praktiese implementering daarvan. Die meganiese ontwerp en konstruksie van ’n pneumatiese bewegingsimulasieplatform word bespreek, sowel as die elektronika en programmatuur wat die werking van hierdie bewegingsimulasieplatform bemoontlik. Wiskundige modelle van die pneumatiese proses en platformoriëntering word ontwikkel. ’n Beheerderargitektuur wat in staat is daartoe om die pneumatiese proses te reguleer, lei tot die suksesvolle beheer van die bewegingsimulasieplatform. Praktiese resultate van die bewegingsimulering van een van die Suid-Afrikaanse Vloot se patrolliekorvette wys daarop dat die bewegingsimulasieplatform wel suksesvol is. Die geslaagde ontwikkeling van die bewegingsimulasieplatform kan grootliks toegeskryf word aan omvangryke navorsing, beplanning en evaluering van die onderskeie ontwikkelingsfases.

In this work, we investigate the active vibration isolation and damping of sensitive equipment. Several single-axis isolation techniques are analyzed and tested. A comparison between the sky-hook damper, integral force feedback, inertial velocity feedback and LagLead control techniques is conducted using several practical examples. The study of single-axis systems has been developed and used to build a six-axis isolator. A six degrees of freedom active isolator based on Stewart platform has been designed manufactured and tested for the purpose of active vibration isolation of sensitive payloads in space applications. This six-axis hexapod is designed according to the cubic configuration; it consists of two triangular parallel plates connected to each other by six active legs orthogonal to each other; each leg consists of a voice coil actuator, a force sensor and two flexible joints. Two different control techniques have been tested to control this isolator : integral force feedback and Lag-Lead compensator, the two techniques are based on force feedback and are applied in a decentralized manner. A micro-gravity parabolic flight test has been clone to test the isolator in micro-gravity environment. ln the context of this research, another hexapod has been produced ; a generic active damping and precision painting interface based on Stewart platform. This hexapod consists of two parallel plates connected to each other by six active legs configured according to the cubic architecture. Each leg consists of an amplified piezoelectric actuator, a force sensor and two flexible joints. This Stewart platform is addressed to space applications where it aims at controlling the vibrations of space structures while connecting them rigidly. The control technique used here is the decentralized integral force feedback.

In this thesis, a combination of density functional theory (DFT) based calculations and nonequilibrium Green’s functions are employed to investigate electron transport in molecular switches, molecular cords and nanoscale devices.   Molecular electronic devices have been proposed as an approach to complement today’s silicon based electronic devices. However, engineering of such miniature devices and design of functional molecular components still present significant challenges.   First, the way to connect a molecule to conductive electrodes has to be controlled. We study, in a nanoelectrode-nanoparticle platform, how structural changes affect the measured conductance and how current fluctuations due to these structural changes can be decreased. We find that, for reproducible measurements, it is important to have the molecules chemically bonded to the surfaces of adjacent nanoparticles. Furthermore, we show by a combination of DFT and theoretical modeling that we can identify signals from single-molecules in inelastic electron spectroscopy measurements on these devices.   Second, active elements based on molecules, some examples being switches, rectifiers or memory devices, have to be designed. We study molecular conductance switches that can be operated by light and/or temperature. By tuning the substituents on the molecules, we can optimize the shift of the most conducting molecular orbital and increase the effective coupling between the molecule and the electrodes when going from the OFF to the ON-state of the switches, giving high switching ratio (up to three orders of magnitude). We also study so called mechanoswitches that are activated by a mechanical force elongating the molecules, which means that these switches could operate as sensors.   Furthermore, we have studied two different classes of compounds that may function either as rigid molecular spacers with a well-defined conductance or as molecular cords. In both cases, we find that it is of great importance to match the conjugation of the anchoring groups with the molecular backbone for high conductance.   The last part of the thesis is devoted to another interesting semiconductor material, diamond. We have accurately calculated the band structure and effective masses for this material. Furthermore, these results have been used to calculate the Hall coefficient, the resistivity and the Seebeck coefficient.

In Automotive Industries, to be confident regarding the success of a planned operation, performing accurate methods in order to detect abnormal operating conditions, known as faults, is crucial. An effective method for diagnosis and fault recognition ensures the safety of the operation, reduces manufacturing cost and any other potential impacts. In addition, mobile solutions have been widely adopted among automotive manufactures during recent years and they have taken full advantage of mobile strategies. Accordingly, it is necessary for there to be a future-proof plan to control the diagnostic operations in advance. In this thesis, the immediate objective has been to offer a future-proof and user-friendly solution to assist engineers and service technicians in the monitoring, detecting, and diagnosing of faults on Toyota/BT/CESAB branded trucks. A mobile cross-platform framework is used to develop the diagnostic mobile solution which is not only able to be deployed on Android and iOS mobile platforms, but also provides wireless communication between truck machines and mobile devices through Bluetooth and Wi-Fi ad hoc technologies. The diagnostic mobile tool is capable of processing real-time controller area network messages and visualizing the condition of different sensors in a more user-friendly way through rich hybrid and client-side web user interfaces. The experience of evaluating a cross-platform diagnostic tool on different mobile operating systems proved that cross-platform mobile development methodology can be a reliable technique for developing projects that essentially require real-time data processing. In addition, it indicates that Apple iOS offers a better runtime performance than Google Android for the current tool.