Dissertations / Theses on the topic 'OPEP devices'

Han sorgit xarxes de laboratoris oberts a tothom i caracteritzats per la seva activitat local i connectivitat global per atendre diferents demandes del usuaris. Open Device Labs (ODLs) és un moviment comunitari de base que té per objectiu democratitzar les proves i l'avaluació en dispositius digitals reals, que fins ara havia estat inexplorat. Els ODLs són un espai normalment equipat amb dispositius mòbils (per exemple: telèfons intel·ligents i tauletes tàctils) connectats a Internet amb la finalitat que els usuaris puguin fer proves de d’aplicacions web, jocs, i mòbils. L’objectiu d’aquesta tesi ha estat investigar l'ecosistema dels Open Device Labs per tal de presentar-ne les seves principals característiques, pràctiques, beneficis i reptes. La recerca s’ha realitzat mitjançant una investigació qualitativa d’estudi de casos i s’ha dividit en quatre unitats centrals. La secció I va explorar l’ecosistema d’ODLs, el local i el global, a través del nucli de la comunitat des de la perspectiva dels amfitrions i centrat en els ODL professionals. La secció II va investigar la perspectiva que tenen els usuaris convidats dels ODLs sobre el servei. La secció III va explorar el potencial de la comunitat per beneficiar-se de la indústria del joc. Per últim, la secció IV presenta un marc per establir ODL acadèmics.
Open labs networks characterised by local activity and global connectivity have emerged to address different demands. Open Device Labs (ODLs) is a grass-roots community movement, which aims to democratise testing and evaluation on real devices, thus far unexplored academically. An ODL is a space typically equipped with mobile devices (e.g. smartphones and tablets) connected to the Internet for Web and app testing purposes. This PhD thesis investigates the ODL ecosystem to identify its main characteristics, practices, benefits, and challenges. We conducted a qualitative inductive case study through four main units. Section I explores the ODL ecosystem, both local and global, through the community core from the hosts’ perspective and focuses on professional ODLs. Section II discusses the investigation of the ODL’s guest users’ perspective of the service. Section III explores the potential of the community to benefit the gaming industry. Section IV examines a single case of an academic ODL. Lastly, the final section presents a framework for establishing academic ODLs.

With the wide spread of mobile phones, PDAs, and Smartphones, M-Commerce has become a major application domain for mobile devices, unlike conventional wired networks, mobile devices allow the user to conduct online transactions regardless of the time and the place as long as there is mobile network coverage. However, online transactions require adequate level of security to insure the confidentiality, the integrity, and the availability of the user’s information. Security measures consume a considerable amount of energy and require more time in processing. The aim of this thesis is to optimise the energy and the resources consumption of mobile phones when applying variant symmetric and asymmetric schemes. This aim can be achieved through developing A System State Security Management Framework, SSSM, which will implement encryption schemes, symmetric and asymmetric, and will provide different options to enable the user to choose the type of encryption, the key size, and number of rounds of computation to optimise the energy consumption level of the mobile phone. This thesis compares the power and the resources consumed by the most commonly used encryption algorithms such as CAST, IDEA, Triple-DES, RSA, and AlGamal. This comparison helps to draw the advantages and disadvantages of each algorithm scheme used in reference to the security level it provides and the power it consumes. Implementing this mechanism will enhance the performance of mobile phones by increasing the security levelsprovided by the encryption schemes and utilising the limited power and resources efficiency. Therefore, confidentiality will be presented in mobile phones and variant encryption schemes, symmetric and asymmetric, and changeable key sizes and rounds, will ensure the authenticity of both senders and recipients depending on their needs as well as resources available. This research makes contributions in two major areas; the first area consists of the novel Energy Aware Encryption polices generated by this work, the second area of contribution is the energy measurements and experimental results which validate the approach presented in the research.

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Attempts have been made at bridging the digital divide in schools using desktop PC systems without much success. As a result many computer laboratories sit empty. There are many reasons for these failures. Often there are incompatibilities of software applications for the PC and its operating systems. In other cases non-existent infrastructure such as networking support for the operations. This paper describes a project aimed at achieving a more successful school educational environment by using students' mobile devices, desktop computer and open source applications. The project therefore, looks forward to a time when schools no longer have to purchase computers for their students but rather utilize mobile devices already owned by students. The paper presents results of an evaluation study on the interaction of students' moble devices with course material and teachers using open source applications in a teaching environment. The pilot project was undertaken by Schoolnet in Namibia. The result presented show that although there were constraints on such devices the educational benefits far outweight the physical limitations.

Development of an Open Source Prosthetic Hand Platform Scott Garrett In the field of upper extremity prosthetic devices, advancements in technology drive the design of products which are becoming capable of restoring the lost functions of the native hand. While several dexterous devices have been developed to serve this purpose, they remain prohibitively expensive and thus are not a viable option for many upper extremity amputees. To address this problem a prosthetic hand platform was developed utilizing the open source Arduino microcontroller and off-the-shelf electrical components. Using these resources, a novel finger actuation mechanism was developed to show how a prosthetic hand platform could be developed which is capable of individual finger actuation, multiple actuation modes, sensing of forces at the individual fingers, providing force feedback to the user, and control of finger actuation through a variety of control inputs. After going through several iterations of hand’s mechanical components, electronics, and firmware a final prototype was built to showcase the possible capabilities of the open source prosthetic hand platform. This prototype consisted of several groups of subcomponents including an auto-flexing / extending finger design, a modular palm/ servo attachment base, and a wrist section which housed the hand’s electronic components, power supplies, force feedback system. The open source prosthetic hand platform was then verified using a series of tests to quantify several performance characteristics of the final prototype. Battery life and grip strength during continuous use were evaluated and demonstrated that the hand could provide consistent grip force during up two hours of initial continuous use. Also, the grip performance of the hand was assessed through the grasping of spherical objects with varying surface textures, diameter, and weight. Furthermore the hand was tested in various “real life” applications including manipulating and sorting small objects, opening doors, grasping moderately heavy objects such as water bottles, and sensitive objects such as an egg. Lastly, the platform was connected to a myoelectric input circuit to demonstrate compatibility with advanced electro-physical inputs. These tests demonstrated that the platform was capable of performing some of the dexterous tasks performed by prohibitively expensive available robotic upper extremity prosthetic devices. Further developments could be made to the open source prosthetic hand platform including enhancements to the platform’s finger force sensing and feedback mechanisms, consolidation of the electronics, refinement of the auto-flexing / extending fingers, and integration with a silicone covering and patients residual limb socket. These future iterations of this platform could help provide a dexterous prosthetic hand platform at lower cost to a wider patient base.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 73-75).
Innovations largely contribute to a technology company's continuous survival and its competitiveness in the market place. Traditionally most companies employed closed innovation model. They kept their discoveries or inventions highly secret and made no attempt to assimilate information from outside. This model worked well until 1990s when advances in technology and society had facilitated information diffusion dramatically. Mobile industry, as one of the most rapidly changing industries, is also forced to adopt the open innovation model in various forms. Recently announced Android platform caused a big stir in the industry. The gradual shift from closeness to openness is inevitable in this industry. A good example of Open Innovation is the open source software development that has been studied extensively. This study further examines the open innovation model beyond software development, i.e. open innovation in hardware and embedded system development. Lessons are learned through case studies of software, hardware and embedded system related business practice. Recommendations are given to Mobile industry, specifically the cell phone handset industry accordingly. This study will not focus on a specific platform or the user side.
by Yuanwen Wayne Liu.
S.M.

Effective device management is not trivial due to a variety of devices and software. To keep costs to minimum companies must effectively utilize a unified solution for device management. This research investigated Funambol’s implementation of Open Mobile Alliance Device Management (OMA DM) which is the most popular device management solution. Interviews were used to set experiments and create realistic test cases. A set of devices and a collection of Funambol software were used to create device management sessions. All of the sessions were recorded, analysed, manipulated and resent to identify efficient ways of device management. Additionally, an influence of compression and buffer-like mechanisms were checked. Methods and guidelines are provided for efficient use of OMA DM as well as a reliable analysis of OMA DM Sessions under various conditions. It was found that for most data it is best to use a built-in transport protocol compressor. Hypertext Transfer Protocol’s (HTTP) deflate with a combination of client-side buffering-like mechanism at a client side performed best at most cases. Funambol’s implementation of the Binary Extensible Markup Language (WBXML), in most cases, performed very badly, even though it was designed specifically to compress OMA DM Session messages. It was found that for an efficient use of OMA DM a proper software option set (e.g. forced use of compression) may be sufficient.

We investigate the some of the many subtleties in taking a microscopic approach to modelling the decoherence of an Open Quantum System. We use the RF-SQUID, which will be referred to as a simply a SQUID throughout this paper, as a non-linear example and consider different levels of approximation, with varied coupling, to show the potential consequences that may arise when characterising devices such as superconducting qubits in this manner. We first consider a SQUID inductively coupled to an Ohmic bath and derive a Lindblad master equation, to first and second order in the Baker-Campbell-Hausdorff expansion of the correlation-time-dependent flux operator. We then consider a SQUID both inductively and capacitively coupled to an Ohmic bath and derive a Lindblad master equation to better understand the effect of parasitic capacitance whilst shedding more light on the additions, cancellations and renormalisations that are attributed to a microscopic approach.

This thesis discusses the possibilities and limitations when developing mobile ap- plications natively vs. HTML5. Research has been carried out to understand how mobile devices can be utilized to its fullest when running applications, and a native iPad application was developed to help in discovering unforeseen challenges. It was developed with a client-server architecture to decrease the amount of work it would take to implement the application natively as a client for all the different mobile platforms.The native approach combined with the client-server architecture is not cross platform by nature, but the study shows that its benefits outweighs the limitations in many cases. It is also shown that time- and cost of the development of an appli- cation favours the HTML5 approach. HTML5 was concluded to be a solution that solves the cross platform problem, but it lacks both performance and API access. However, the type of application developed should be the deciding factor of what solution to choose.

Organic photovoltaic devices continue to attract attention as they offer the prospect of low-cost energy production on flexible substrates. However, there remains a need to understand factors which affect device performance at a more fundamental level. One particular area of focus has been related to the device open-circuit voltage (Voc) whose origins are still the subject of debate. This thesis therefore sets out to try and understand and correlate the electronic properties of materials with critical device parameters, such as the Voc. The experimental determination of the work function, ionisation potential and electron affinities are important for predicting and understanding the energetics at the interface formed when two solids are combined. The offsets at the interface between different oxide / phthalocyanine / fullerene heterojunctions were characterised. It was found that the upper limit to Voc is governed by the offsets between the HOMO state in the donor and the LUMO state of the acceptor (the effective bandgap). Furthermore, by understanding the electronic structure and characterising device performance in the limit of low temperature, it was found that the experimental Voc is limited by the reverse saturation current and the exciton binding energy - a bottleneck for organic semiconductors. An understanding of the benefits of incorporating molybdenum oxide into a device architecture was achieved by conducting a thorough investigation on its electronic structure. The conduction mechanism is believed to be dictated by a distribution of near Fermi level defect states caused by non-stoichiometry. Finally, the effects of tuning the molecular orientation on the device performance were investigated with a flat lying perylene derivative. Optimised device architectures based on the photoactive ClAlPc / C60 heterojunction displayed an efficiency of 3.0 %.

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California
When designing data transport systems, Telemetry and Communications engineers always face the risk that their chosen hardware will not be available or supported soon after the hardware has been installed. The best way to reduce this risk and ensure the longevity of the system is to select an open architecture standard that is supported by multiple manufacturers. This open architecture should also have the ability to be easily upgraded and provide for all of the features and flexibility that are required to be a reliable carrier-grade edge-device. The PCI Industrial Computer Manufacturers Group (PICMG) developed the MicroTCA open standard to address the specific needs of these Communications and Network System Engineers. This paper describes the MicroTCA architecture and how it can be applied as the ideal edge-device solution for Networked Telemetry Systems applications.

This thesis takes a fresh look at software, treating it as a document, manuscript, corpus, or text to be consumed among communities of programmers and uncovering the social roles of these texts within two specific sub-communities and comparing them. In the paper, the social roles of the texts are placed within the context of the technical and cultural constraints and environments in which programs are written. Within that context, the comments emphasize the metaphoric status of programming languages and the social role of the comments themselves. These social roles are combined with the normative intentions for each comment, creating a dynamic relationship of form and function for both normative and identity-oriented purposes. The relationship of form and function is used as a unifying concept for a more detailed investigation of the construction of comments, including a look at a literary device that relies on the plural pronoun â weâ as the subject. The comments used in this analysis are derived from within the source code of the Linux kernel and from a Corporate environment in the US.
Master of Science

El propòsit d'aquesta tesi doctoral és entendre els hàbits i comportaments d'aprenentatge dels estudiants que utilitzen diferents dispositius per a aprendre amb la finalitat de determinar com duen a terme les activitats d'aprenentatge utilitzant les diferents tecnologies de què disposen en els diferents llocs on es mouen, a més de diagnosticar els diferents tipus de suport que requereixen durant l'aprenentatge. La recerca utilitza com a mostra d'estudi dues universitats d'aprenentatge obert i a distància (AOD): una situada a Espanya i una altra situada a Sud-àfrica. Els resultats demostren que els estudiants són capaços de continuar l'aprenentatge en múltiples contextos i ubicacions fent servir múltiples dispositius (tecnologies mòbils i personals) i internet. En aquest sentit, l'aprenentatge és ininterromput. Així, doncs, les universitats d'AOD necessiten redefinir el seu disseny d'aprenentatge i els serveis de suport a l'estudiant durant l'aprenentatge.
El propósito de esta tesis doctoral es entender los hábitos y comportamientos de aprendizaje de los estudiantes que utilizan diferentes dispositivos para aprender con el fin de determinar cómo llevan a cabo las actividades de aprendizaje utilizando las diferentes tecnologías de las que disponen en los distintos lugares donde se mueven, además de diagnosticar los diferentes tipos de apoyo que requieren durante el aprendizaje. La investigación utiliza como muestra de estudio dos universidades de aprendizaje abierto y a distancia (AAD): una situada en España y otra situada en Sudáfrica. Los resultados demuestran que los estudiantes son capaces de continuar el aprendizaje en múltiples contextos y ubicaciones usando para ello múltiples dispositivos (tecnologías móviles y personales) e internet. En este sentido, el aprendizaje es ininterrumpido. Así, pues, las universidades de AAD necesitan redefinir su diseño de aprendizaje y los servicios de apoyo al estudiante durante el aprendizaje.
The objective of this doctoral thesis is to understand the learning habits and behaviours of students using different devices in their learning in order to determine how they move between technologies, locations and learning activities, and the types of support they require. A mixed methods case study was conducted at two open and distance learning (ODL) universities, one in Spain and one in South Africa. Students are able to continue their learning experiences across different contexts and settings with the aid of mobile and personal technologies, together with internet services. This fulfils the aim of seamless learning. The results of the study will enable universities to design better learning experiences or offer improved support services to better meet the needs of students using multiple devices.

A field study of the feasibility and the performance of a sustainable drainage technique combined with a renewable energy device to provide heating in a domestic setting was carried out from March 2008 to November 2010 to acquire practical data about the system’s operation. Among all the sustainable drainage techniques, permeable pavement system (PPS) was selected to be applied in this project since this particular technique can be used for driveways and car-parking hard standings, but more specially they can be designed as a tanked system whereby an impermeable membrane is installed at the bottom of the tank in order to hold the rainwater collected as runoff from hard areas and roofs before releasing it in a controlled manner. The renewable energy device applied in this study is a ground source heat pump system (GSHP), which has been found in previous studies to provide a better performance when installed in wet conditions. Based on this, the PPS and the GSHP with horizontal ground heat exchanger (GHE) were integrated in a 350mm deep reservoir under ‘real life’ conditins. The combined system operated in heating mode in a family–sized, three bedrooms detached EcoHouse at the Building Research Establishment Innovation Park, Watford, UK. Monitoring the combined system included taking measurements of the temperature of the conditioned space, the ground around the PPS/GSHP system, and of the ambient air every 10 minutes. Assessing the performance of the PPS/GSHP system involved investigating the effect of extracting heat via the GHE on the ground temperature, the impact of the PPS/GSHP on the thermal profile of the air above the surface of the reservoir, and computing the PPS/GSHP coefficient of performance (CoP). The thesis includes information about the design of the PPS/GSHP system including the structure of the sub-base, types and size of the used aggregate and stone, the depth of the excavated reservoir amongst others, also the technical problems that materialized, largely due to the fact that the PPS/GSHP was installed and operating under real-life circumstances. Results obtained from the study provided evidence for the workability of the combined system in regards of stormwater management and of providing heat to the EcoHouse. However, monitoring the rainwater stored in the reservoir showed that, due to leakage, the top part of the buried coil was not covered with water. The monitoring also revealed that the rainwater surrounding parts of the coil was, in severe weather, frozen. Moreover, highly significant correlations (p<0.01) were calculated for the ambient air and the ground temperature relationships with the CoP. All of these factors resulted in a 1.8 coefficient of performance being obtained. This low figure was related to the shallow depth of the reservoir since it became clear that its ground temperature was greatly influenced by the ambient air temperature. The study also revealed that the evaporation process was prevented from occurring due to the Inbitex™ composite layer, as a result there was no significant effect on cooling the thermal profile of the air near the surface of the pavement. Furthermore, it was concluded that continuous heat extraction from the ground contributed to an underground temperature drop.

This thesis describes an investigation into the spatial species conversion profiles of a Cu-zeolite SCR under engine conditions at low exhaust gas temperatures; this was then compared with a CFD model that models the catalyst via a porous medium measuring 5 x 5 x 91 cells assuming a uniform cross-sectional flow distribution. Species conversion rates were sampled at fixed points in the axial direction. The analysis of the spatial conversion profiles is a more rigorous method in assessing the ability of a mathematical model to predict the experimental data. It can also assist in the optimisation of the catalyst size, minimising packaging requirements and manufacturing costs. The experiments were undertaken on a light-duty diesel engine at a speed of 1500rpm, and at a load of 6bar BMEP; this provided exhaust gas temeraqtures between 200 and 220°C. NO2:NOx ratios were controlled by changing the size and position of the diesel oxidation catalyst, the inlet NH3: NOx ratio was also also varied, ammonia gas was used instead of urea for the purposes of simlicity. The advantage of testing on an actual engine over lab-babed studies is that the conditions such as exhaust gas composition are more realistic. A 1D CFD model was constructed using the ‘porous medium approach’ with kinetics obtained from open literature. Results from the simulations were then compared with the experimental data for the same engine conditions. It was observed that the majority of the NOx conversion took place in the first half of the brick for all NH3: NOx ratios investigated, and that the formation of N2O via NO2 and ammonia had the same influence as the ‘fast’ SCR reaction just after the inlet, which the CFD model failed to predict for the base case analyses. The influence of the inlet ammonia on the model was also noticed to be greater than in the experiments. Simple transient analyses were also undertaken on the short SCR bricks for NO2: NOx ratios of 0.6 and 0.07, and it was observed that the response time to steady-state was noticeably higher in the experiments than in the model. Modifications made to the model, including decreasing the influence of the ‘fast’ SCR reaction, and the addition of an empirical term onto the ammonia adsorption provided a noticeably better agreement for different NH3: NOx injection ratios. The desorption kinetics in the model were also altered by increasing the strength of the bonding of the ammonia onto the adsorption sites. This improved the transient agreement between the model and the experiments, but reduced the steady-state concentrations at the exit of the brick for all NH3:NOx ratios investigated.

The relationship people have to electronic devices relys on their passive acceptance rather than an understanding of their functioning – often leaving the users alientated and helpless as their products break. Which qualities do electronic artifacts need to embody in order to be repairable? As opposed to a black-box, the metaphor of a white-box can describe this repairable ideal: A white-box is meant to be opened and allows easy access to all inner parts. It is designed to communicate functions and connections and aids the user in understanding. Therefore, a white-box is designed to allow the consumer to act. How «open» can household electronics be?

The question of context in architecture theory has become more complex and controversial as globalization, urbanisation and resource scarcity have added yet more layers to the debate (O’Donnell 2016:380). As these aspects increasingly enter every facet of our lives, its effect on architecture has resulted in a development approach that is exploitative of people, nature and culture (Fioramonti 2017:3). This study argues that working with scarcity in a productive manner could lead to an alternative approach for development. A critical look at the continuum of architectural discourse and its engagement with issues of context will place the debate in a broad historical context which ranges from theories posed by Vitruvius to current theories on the vernacular, to establish the role of the architect as an enabler of social space. An in-depth context analysis of the spatial logics found in Mamelodi East (City of Tshwane, South Africa) will consider the spatial relationship and rules of engagement that allow certain patterns of living and public exchange to emerge. This paper argues that there are key lessons to be learnt from this logic because of the way in which people are resolving daily problems under the construction of scarcity. Till (2014:9) argues that scarcity will become an inevitable feature of modern life. However, these limits will not lead to the end of design or an emasculated version of it, but will rather open up new fields in which the designer may operate. The strength thus lies in defining a response to a vernacular through its understanding of scarcity and the rules of engagement in which new roles and opportunities through architecture can emerge.
Konteks in argitektuurteorie word meer kompleks en kontroversieel soos globalisering, verstedeliking en hulpbronskaarste meer lae by die debat voeg (O’Donnell 2016: 380). Namate hierdie aspekte elke faset van ons lewe betree, lei dit tot ‘n ontwikkelingsbenadering wat die uitbuiting van mense, natuur en kultuur tot gevolg het (Fioramonti 2017: 3). Hierdie studie is van mening dat die produktiewe omgang met skaarste, ‘n alternatiewe benadering tot ontwikkeling kan wees. ‘n Kritiese ontleding van argitektoniese diskoers en die dissipline se betrokkenheid by kontekstuele kwessies plaas die debat in ‘n breë historiese konteks - van Vitrivius tot die hedendaagse teorieë - om sodoende die rol van die argitek as ‘n fasiliteerder van sosiale ruimte te identifiseer. ‘n In-diepte konteksanalise van die ruimtelike logika van Mamelodi- Oos (Tshwane, Suid-Afrika), sal die verhouding en onderliggende reëls vir sosiale en ruimtelike interaksie ontleed. Dit is hierdie verhouding wat sekere lewenstylpatrone en sosiale interaksie moontlik maak. Hierdie studie beweer dat daar belangrike lesse uit hierdie logika geleer kan word, omdat mense, temidde van die skaarste aan hulpbronne, hulle daaglikse probleme oplos. Till (2014:9) beweer dat skaarsheid ‘n onvermydelike aspek van die moderne lewe sal word. Hierdie beperkinge sal nie noodwendig tot die einde van ontwerp of ‘n magtelose weergawe daarvan lei nie, maar sal eerder nuwe uitdagings vir die ontwerper bied. Die waarde lê daarin om deur ‘n studie van die volkstaalargitektuur wat op die skaarsheid van hulpbronne en die reëls vir sosiale interaksie gebasseer is, nuwe rolle en geleenthede vir formele argitektuur te skep.
Mini Dissertation MArch(Prof)--University of Pretoria, 2018.
Architecture
MArch(Prof)
Unrestricted

With the purpose of finding the motives behind use, production and reuse of Open Educational Resources (OER), the writer has conducted a qualitative survey. The three main questions in this two years master‟s thesis are: • Why do people use others‟ unmodified OER? • Why do people produce OER? • Why do people alter and reuse OER? The theoretic framework is built around Manuel Castells‟ network society, with its social and efficiency seeking dimension, along with the Knowledge commons. Some pedagogy is included as well. A web survey was distributed to 796 users of the Connexions OER repository. 95 responses were received. The results reveal the users, producers and reusers to be a diverse crowd. The belief in sharing knowledge and information is put forth as a motive behind taking part in the OER circuit, as are more practical thoughts about use in teaching or learning situations. Continuing reuse of own material is popular. The quality of material and user interfaces are claimed to be barriers against use. The verdict is not un-animous however, and there are possible signs of improvement ahead. Furthermore, the community around OER is described with warmth and surprise by several respondents. Among faculty the support for OER is varied, but on the internet the communication and encouragement is glob-al.

Introduction: Surgical abdominal sepsis has traditionally been managed with by a single staged procedure, otherwise known as primary abdominal closure (PAC). An on demand laparotomy may be performed for post-operative clinical deterioration. Open abdomen and a planned re-laparotomy with vacuum assisted closure (VAC) is an alternate method to single staged procedure. Inflammatory cytokines can potentially help stratify severity of sepsis and guide surgical management. The objective of the study was to identify if inflammatory cytokines could differentiate between PAC and VAC. Secondary objectives were to see if cytokines could predict mortality and characterize longitudinal cytokine profiles during open abdomen management. Severity of disease between surgical groups was compared using the Acute Physiology and Chronic Health Assessment (APACHE)-IV predictive mortality rate (PMR) calculator. Methods: Prospective case series between December 2011 to June 2013. Patients were included if they met criteria of severe abdominal sepsis/septic shock requiring urgent source control laparotomy (SCL). Blood and peritoneal samples were obtained pre- and post-operatively at primary SCL in patients who underwent PAC and VAC management. Peritoneal fluid (PF) samples were obtained once the peritoneum was entered. Blood and peritoneal samples were obtained for re-look laparotomies in the VAC group. Samples were centrifuged within 1 hour and stored at -70 degrees Celsius. Samples were analyzed with a Human Cytokine 30-plex Panel and concentrations were reported as pg/ml. Results: 12 patients were included (4 PAC and 8 VAC). PF cytokine concentrations of IL 6, IL-17, IL-5 and HGF were significantly higher in VAC compared to PAC. Peritoneal fluid at primary SCL did not differentiate between survivors and non-survivors. Pre-operative serum RANTES was significantly elevated in survivors compared to non-survivors. Pre operative serum VEGF, IL-1b, FGF-b, IL-5, IL-4, IL-7 and post-operative serum VEGF, IL-7 differentiated between VAC survivors and non-survivors at second SCL. Conclusion: VAC management was utilized in patients with elevated peritoneal cytokines compared to single staged procedures. Increased peritoneal inflammatory cytokine concentrations in VAC represent a more severe degree of local sepsis. Pro and anti-inflammatory cytokines are both elevated in the early and late phases of surgical abdominal sepsis.
Medicine, Faculty of
Surgery, Department of
Graduate

An investigation into technologies to detect impaired performance due to driver fatigue was undertaken. From this, a new forced-choice stimulus-reaction device was developed specifically to detect driver impairment in operators of haul trucks in open cut mines. The device was developed in conjunction with personnel from the mining industry to suit the harsh conditions of the mining environment. The technology was trialled in three open cut mines and in a driving simulator at Murdoch University in Western Australia. Data were collected on the performance of drivers and analysed to validate the technology. A significant positive correlation was found between measures of reduced operator reaction performance and measures of eye closure. It was found that the device detected few false alarms and missed few bouts of tiredness as indicated by eye closures. It is suggested that the device would be a useful tool to assist with the detection of driver fatigue in open cut mining environments. The forced-choice reaction-monitoring device was used to assess the performance of drivers in a gold mine in Kalgoorlie, Western Australia. The fly-in-fly-out haul truck drivers worked 14 consecutive 12-hour night shifts, had a day off, then worked 13 consecutive 12-hour day shifts. A total of more than 3,500 hours of real-time objective performance data were collected and analysed. The main findings were that the objective performance data showed patterns of low performance that did not fit some of the performance data that would be expected from examination of past literature. Many findings are discussed in light of these anomalies. Another important finding is that the subject’s background and sleep pathology is a possible predictor for poor performance on the forced-choice reaction task. The system was also used to measure the performance of drivers with rising blood alcohol levels in a driving simulator. Subjects drank vodka with a mixer while driving for two hours starting at both 20:00 hrs and 22:00 hrs, with a week in between the two trials. The fatigue monitor detected reaction times slower than 3 SD of baseline performance at low levels of BAC. Performance at 22:00 hrs was marginally more impaired than performance at 20:00 hrs. Drivers at low BAC levels tended to compensate easier on the reaction task at 20:00 hrs compared to at 22:00 hrs. The ARRB fatigue monitor shows good capacity to detect poor performance due to low and medium measures of BAC. The research undertaken within this thesis has provided data that challenges contemporary research that generally suggests that time on task is one of the largest influences of fatigue at work. It appears that both circadian influences and individual lifestyle habits will have an equal or greater impact on fatigue risk at work.

An investigation into technologies to detect impaired performance due to driver fatigue was undertaken. From this, a new forced-choice stimulus-reaction device was developed specifically to detect driver impairment in operators of haul trucks in open cut mines. The device was developed in conjunction with personnel from the mining industry to suit the harsh conditions of the mining environment. The technology was trialled in three open cut mines and in a driving simulator at Murdoch University in Western Australia. Data were collected on the performance of drivers and analysed to validate the technology. A significant positive correlation was found between measures of reduced operator reaction performance and measures of eye closure. It was found that the device detected few false alarms and missed few bouts of tiredness as indicated by eye closures. It is suggested that the device would be a useful tool to assist with the detection of driver fatigue in open cut mining environments. The forced-choice reaction-monitoring device was used to assess the performance of drivers in a gold mine in Kalgoorlie, Western Australia. The fly-in-fly-out haul truck drivers worked 14 consecutive 12-hour night shifts, had a day off, then worked 13 consecutive 12-hour day shifts. A total of more than 3,500 hours of real-time objective performance data were collected and analysed. The main findings were that the objective performance data showed patterns of low performance that did not fit some of the performance data that would be expected from examination of past literature. Many findings are discussed in light of these anomalies. Another important finding is that the subject's background and sleep pathology is a possible predictor for poor performance on the forced-choice reaction task. The system was also used to measure the performance of drivers with rising blood alcohol levels in a driving simulator. Subjects drank vodka with a mixer while driving for two hours starting at both 20:00 hrs and 22:00 hrs, with a week in between the two trials. The fatigue monitor detected reaction times slower than 3 SD of baseline performance at low levels of BAC. Performance at 22:00 hrs was marginally more impaired than performance at 20:00 hrs. Drivers at low BAC levels tended to compensate easier on the reaction task at 20:00 hrs compared to at 22:00 hrs. The ARRB fatigue monitor shows good capacity to detect poor performance due to low and medium measures of BAC. The research undertaken within this thesis has provided data that challenges contemporary research that generally suggests that time on task is one of the largest influences of fatigue at work. It appears that both circadian influences and individual lifestyle habits will have an equal or greater impact on fatigue risk at work.

An investigation into technologies to detect impaired performance due to driver fatigue was undertaken. From this, a new forced-choice stimulus-reaction device was developed specifically to detect driver impairment in operators of haul trucks in open cut mines. The device was developed in conjunction with personnel from the mining industry to suit the harsh conditions of the mining environment. The technology was trialled in three open cut mines and in a driving simulator at Murdoch University in Western Australia. Data were collected on the performance of drivers and analysed to validate the technology. A significant positive correlation was found between measures of reduced operator reaction performance and measures of eye closure. It was found that the device detected few false alarms and missed few bouts of tiredness as indicated by eye closures. It is suggested that the device would be a useful tool to assist with the detection of driver fatigue in open cut mining environments. The forced-choice reaction-monitoring device was used to assess the performance of drivers in a gold mine in Kalgoorlie, Western Australia. The fly-in-fly-out haul truck drivers worked 14 consecutive 12-hour night shifts, had a day off, then worked 13 consecutive 12-hour day shifts. A total of more than 3,500 hours of real-time objective performance data were collected and analysed. The main findings were that the objective performance data showed patterns of low performance that did not fit some of the performance data that would be expected from examination of past literature. Many findings are discussed in light of these anomalies. Another important finding is that the subject's background and sleep pathology is a possible predictor for poor performance on the forced-choice reaction task. The system was also used to measure the performance of drivers with rising blood alcohol levels in a driving simulator. Subjects drank vodka with a mixer while driving for two hours starting at both 20:00 hrs and 22:00 hrs, with a week in between the two trials. The fatigue monitor detected reaction times slower than 3 SD of baseline performance at low levels of BAC. Performance at 22:00 hrs was marginally more impaired than performance at 20:00 hrs. Drivers at low BAC levels tended to compensate easier on the reaction task at 20:00 hrs compared to at 22:00 hrs. The ARRB fatigue monitor shows good capacity to detect poor performance due to low and medium measures of BAC. The research undertaken within this thesis has provided data that challenges contemporary research that generally suggests that time on task is one of the largest influences of fatigue at work. It appears that both circadian influences and individual lifestyle habits will have an equal or greater impact on fatigue risk at work.

Urbanisation, a process associated with industrialisation and development has been characterised by unsustainable impacts such as increased impervious surfaces, increased air pollution, increased use of natural resources, increased volume of surface run-off, decreased quality of surface run-off, and depletion of biodiversity and habitats. The effects of these impacts on the environment include climate change, flooding, erosion, pollution of water bodies, and destruction of aquatic life and biodiversity. Studies have shown that sustainable designs such as Sustainable Drainage Systems (SuDS) would help mitigate some of these effects sustainably. SuDS are natural drainage systems that simulate the natural drainage of a site/catchment and work in harmony to achieve increase in ground infiltration and treatment of runoff; and reduction in flow rates and volume of surface runoff, thereby improving storm water quality, reducing erosion, recharging groundwater, improving biodiversity and ultimately improving sustainability. However, sustainability of SuDS devices are questionable because their component parts involve the use of natural resources i.e. topsoil and gravel. The overall aim of this research was to evaluate the efficacy of the application of recycled/waste materials in performing at least as well as topsoil and gravel in vegetative SuDS, thereby improving water quality and overall sustainability. The materials applied were compost and recycled aggregates. In assessing their efficacy in vegetative SuDS, the risk these materials could pose to water quality was not overlooked but was considered in establishing an ideal model for the treatment of pollutants in vegetative SuDS. Results of this research showed that overall compost and recycled aggregates were able to perform at least as well as gravel and topsoil in vegetative SuDS in terms of characterisation, biofilm and vegetative development, and remediation of runoff pollutants thereby improving the sustainability of vegetative SuDS. Compared to gravel and topsoil, characterisation of compost and recycled aggregates was shown to be less expensive, less time consuming (except for recycled aggregates) and more sustainable, in terms of conserving natural resources. It was deduced that compost would be able to biodegrade organic pollutants in vegetative SuDS in varying conditions, compared to topsoil, thereby improving water quality. Vegetative growth in profiles containing compost were more prolific than those with topsoil alone, indicating that vegetative SuDS containing compost would attenuate stormwater and remediate pollutants by phytoremediation, better than topsoil. Results showed that compost and recycled aggregates performed as well as gravel and topsoil in remediating pollutants, with >98% of pollutants being retained mostly within the growth media, confirming that most pollutants are treated within the growth media of vegetative SuDS devices. This research was able to establish that SuDS components can be as unsustainable as components of conventional drainage systems in terms of their social, economic and environmental impacts; and that recycled materials could perform just as well as conventional materials, whilst improving their sustainability. This research further established that compost and recycled aggregates can be used in vegetative SuDS, such as swales, as literature has shown that the use of compost and recycled aggregates in vegetative SuDS has been limited to compost blankets and socks and substrates for green roofs. Suggestions for other waste materials that can be used instead topsoil and gravel in vegetative SuDS were also made. Results from this research were applied in the development of a swale model for the treatment of pollutants in vegetative SuDS.

The overarching theme of the thesis was to investigate the association between smart device use and computer vision syndrome. The initial study designed and developed the Open Field Tear film Analyser (OFTA) enabling a continuous, real-time assessment of the tear film and blink characteristics during smart device use. The monocular OFTA prototype was validated and showed good intra- and inter-observer repeatability relative to the Oculus Keratograph 5M and Bausch and Lomb one position keratometer. Subsequently, tear osmolarity following engagement with reading and gaming tasks on smart device and paper platforms was investigated. Discrete measures of osmolarity pre- and post-engagement with the tasks were obtained with the TearLab osmometer; osmolarity values differed between platforms when participants were engaged in a gaming task but no such difference was observed with the reading task. In addition, the influence of repeated measurements on tear osmolarity was also explored. To simulate the habitual binocular viewing conditions normally associated with smart device use, the binocular OFTA was developed. The device was used to assess the tear film and blink characteristics whilst engaging with reading and gaming tasks on smart device and paper platforms. The results revealed differences in blink characteristics and non-invasive tear break up time between the different platforms and tasks assessed. In addition, the thesis also reports on an investigation examining the real-time accommodative response to various targets displayed on smart devices using an open-field autorefractor with a Badal lens system adaptation. The results showed that accommodative latency, accommodative lag, mean velocity of accommodation, speed of disaccommodation and mean velocity of disaccommodation varied across the different platforms. Through the use of validated subjective questionnaires and smartphone apps, the relationship between duration of smartphone use and symptoms of dry eye were examined. The findings of this study demonstrated that longer duration of smartphone and personal computer use were associated with higher risk of dry eyes as indicated by subjective questionnaire outcomes.

3D printable materials for RF devices need improvement in order to satisfy the demand for higher frequency and lower loss performance. Characterization of materials that have shown improvements of conductor conductivity have been performed. By using a laser machining technique the loss of a 3D printed 2.45 GHz microstrip Square Open Loop Resonator (SOLR) bandpass filter has been shown to improve by 2.1dB, along with an increase in bandwidth from 10% to 12.7% when compared to a SOLR filter that has not been laser machined. Both laser machined and microwaved silver inks have been mapped for conductivity using a Near Field Microwave Microscope (NFMM) and have shown improvement of conductivity compared to inks that have been cured using standard methods.

Este estudo trata da acontecimentalização da/na Escola Municipal Porto Alegre (EPA), escola aberta para jovens em situação de vulnerabilidade social no município de Porto Alegre. Sob princípio cartográfico, utiliza narrativas dos professores, dos estudantes e da própria pesquisadora como construções subjetivas que explicitam como a vida se tece e a escola acontece entre-vidas. Para realização desse exercício de tecer e tramar conceitos e práticas foram utilizados os seguintes operadores: dispositivo, acontecimento, entre-vidas, narratividade e cartografia, embasados nas teorias foucaultiana e deleuziana. Para situar a escola aberta no tempo foi utilizado um plano, o histórico em que se analisa o Código de Menores e o Estatuto da Criança e do Adolescente como dispositivos e outro, o cartográfico, que analisa a intensidade das práticas, das expressões, dos (des)afetos na acontecimentalização da EPA, ressaltando elementos que potencializam a expansão, ou não, da vida. Questiona e desvela a EPA como um dispositivo de cuidado e acolhimento na racionalidade do Estado. Em sua fragilidade institucional, do não-lugar dado pela intersetorialidade entre educação, saúde, assistência, sua identidade é conhecida nesse pouco de tudo. A EPA sobrevive nesse não-lugar pela luta e pela resistência no tempo próprio entre a educação menor a a educação maior, afirmando uma potência de ação que exige força e invenção numa longa história de fatos de dominação e de opressão, principalmente, entre crianças e jovens e aqueles feitos “menores” por estarem desassistidos. Busca conhecer pistas construídas pelos jovens estudantes e educadores a respeito da política pública e da invenção de novos espaços, de novas possibilidades ética, estética e política, de novas teias que escapem aos saberes e fazeres instituídos.
This study approaches the eventalization of/in Escola Municipal Porto Alegre (EPA), an open school for young people in situation of social vulnerability in the city of Porto Alegre. Under principles of cartographic, it uses narratives of teachers, students and even the researcher as subjective constructions that explain how life is woven and how school happens between lives. In order to perform this exercise of weaving and plotting concepts and practices, the following operators were used: device, event, between lives, storytelling and cartography, based on Foucauldian and Deleuzian theories. To situate the open school in time, it was used a historic plan in which the Juvenile Code and the Child and Adolescent Statute are analyzed as devices, as well as the cartographic one, which analyzes the intensity of practices, expressions, (dis)affection in the eventalization of EPA, highlighting elements that enhance the expansion, or not, of life. It questions and unveils EPA as a care device in the rationality of the state. In its fragility, of the non-place given by the intersectionality among education, health and care, its identity is known in this bit of everything. EPA survives in this non-place by the struggle and resistance in the proper time between minor and higher education, claiming a power of action that requires strengths and invention in a long history of facts of domination and oppression, mainly among children and youngsters and those made “minor” by being disadvantaged. The study seeks to discover clues built by youngsters, students and by educators regarding public policy and invention of new spaces, new ethics, aesthetics and political possibilities, and new webs that are beyond knowledge and practices in place.

Thesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, 2009.
"April 2008." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 79-80).
At the beginning of 2009, the global mobile industry is in the midst of a revolution, characterized by a trend towards openness, driven by technological advances, evolving consumer demands and increasing competition. Open mobile operating systems, which allowed third party software development, have existed since 2001, but they haven't had much effect on the industry's business ecosystem or the customers' expectations and demands. The release of the iPhone in 2007 had profound impact not only on dominant design of smartphones and on consumers' expectations, but also on the balance of power in the mobile industry amongst network operators, mobile device manufacturers and software developers. The trend continued with the subsequent announcements of leading industry players that they will develop open source operating systems for mobile phones, and make them accessible to everyone. Today, top mobile device manufacturers are on the verge of releasing dozens of new devices running open source operating systems, which has the potential to completely change the current market share of the players in the market. The purpose of this thesis is to guide product managers in the mobile industry. It examines the historical and current structure of the mobile business ecosystem, reviews latest developments in open operating systems and open source platforms and their affects on industry players today, and identifies potential influences and developments for the future based on analysts' reports assessment, industry experts' viewpoints study, and interviews with industry executives.
by Ofri Markus.
S.M.

As the world population ages, the healthcare system is facing new challenges in treating more patients at a lower cost than today. One trend in addressing this problem is to increase the opportunities of in-home care. To achieve this there is a need for safe and cost-effective monitoring systems. Biosignal PI is an ongoing open-source project created to develop a flexible and affordable platform for development of stand-alone devices able to measure and process physiological signals. This master thesis project, performed at the department of Medical Sensors, Signals and System at the School of Technology and Health, aimed at further develop the Biosignal PI software by constructing a new flexible software framework architecture that could be used for measurement and processing of different types of biosignals. The project also aimed at implementing features for Heart Rate Variability(HRV) Analysis in the Biosignal PI software as well as developing a graphical user interface(GUI) for the Raspberry PI hardware module PiFace Control and Display. The project developed a new flexible abstract software framework for the Biosignal PI. The new framework was constructed to abstract all hardware specifics into smaller interchangeable modules, with the idea of the modules being independent in handling their specific task making it possible to make changes in the Biosignal PI software without having to rewrite all of the core. The new developed Biosignal PI software framework was implemented into the existing hardware setup consisting of an Raspberry PI, a small and affordable single-board computer, connected to ADAS1000, a low power analog front end capable of recording an Electrocardiography(ECG). To control the Biosignal PI software two different GUIs were implemented. One GUI extending the original software GUI with the added feature of making it able to perform HRV-Analysis on the Raspberry PI. This GUI requires a mouse and computer screen to function. To be able to control the Biosignal PI without mouse the project also created a GUI for the PiFace Control and Display. The PiFace GUI enables the user to collect and store ECG signals without the need of an big computer screen, increasing the mobility of the Biosignal PI device.   To help with the development process and also to make the project more compliant with the Medical Device Directive a couple of development tools were implemented such as a CMake build system, integrating the project with the Googletest testing framework for automated testing and the implementation of the document generator software Doxygen to be able to create an Software Documentation.    The Biosignal PI software developed in this thesis is available through Github at https://github.com/biosignalpi/Version-A1-Rapsberry-PI
Allt eftersom världens befolkning åldras, ställs sjukvården inför nya utmaningar i att behandla fler patienter till en lägre kostnad än idag. En trend för att lösa detta problem är att utöka möjligheterna till vård i hemmet.För att kunna göra detta finns det ett ökande behov av säkra och kostnadseffektiva patientövervakningssystem. Biosignal PI är ett pågående projekt med öppen källkod som skapats för att utveckla en flexibel och prisvärd plattform för utveckling av fristående enheter som kan mäta och bearbeta olika fysiologiska signaler. Detta examensarbete genomfördes vid institutionen för medicinska sensorer, signaler och system vid Skolan för Teknik och Hälsa. Projektet syftade till att vidareutveckla den befintliga mjukvaran för Biosignal PI genom att skapa ett nytt flexibelt mjukvaruramverk som kan användas för mätning och bearbetning av olika typer av biosignaler.Projektet syftade också till att utvidga mjukvaran och lägga till funktioner för att kunna genomföra hjärtfrekvensvariabilitets(HRV) analys i Biosignal PIs mjukvara, samt att utveckla ett grafiskt användargränssnitt(GUI) för hårdvarumodulen PiFace Control and Display. Projektet har utvecklat ett nytt flexibelt mjukvaruramverk för Biosignal PI. Det nya ramverket konstruerades för att abstrahera alla hårdvaruspecifika delar in i mindre utbytbara moduler, med tanken att modulerna ska vara oberoende i hur de hanterar sin specifika uppgift. På så sätt ska det vara möjligt att göra ändringar i Biosignal PIs programvara utan att behöva skriva om hela mjukvaran.Det nyutvecklade Biosignal PI ramverket implementerades i det befintliga hårdvaru systemet, som består av en Raspberry PI, liten och prisvärd enkortsdator, ansluten till ADAS1000, en analog hårdvarumodul med möjlighet att registrera ett elektrokardiografi(EKG/ECG). För att kontrollera Biosignal PI programmet har två olika grafiska användargränssnitt skapats.Det ena gränssnitt är en utvidgning av original programvaran med tillagd funktionalitet för att kunna göra HRV-Analys på Raspberry PI, detta gränssnitt kräver dock mus och dataskärm för att kunna användas.För att kunna styra Biosignal PI utan mus och skärm skapades det även ett gränssnitt för PiFace Control and Display. PiFace gränssnittet gör det möjligt för användaren att samla in och lagra EKG-signaler utan att behöva en stor datorskärm, på så sätt kan man öka Biosignal PI systemets mobilitet. För att underlätta utvecklingsprocessen, samt göra projektet mer förenligt med det medicintekniska regelverket, har ett par utvecklingsverktyg integrerats till Biosignal PI projektet såsom CMake för kontroll av kompileringsprocessen, test ramverket Googletest för automatiserad testning samt integrering med dokumentations generatorn Doxygen för att kunna skapa en dokumentation av mjukvaran.

Includes bibliographical references
Purpose: Cardio-respiratory physiotherapy for patients undergoing abdominal surgery has been found to be beneficial in improving lung function post-operatively and in the prevention and treatment of post-operative pulmonary complications (PPCs). The Blow Bottle, a Positive Expiratory Pressure (PEP) therapy device, is commonly used as an adjunct to physiotherapy. The Blow Bottle is low cost and can be easily made by the physiotherapist using readily available materials in the hospital setting. However, evidence to support the use of Blow Bottles in the post-operative management of abdominal surgery is minimal, with few studies reporting significant positive effects especially when compared to conventional cardio-respiratory physiotherapy techniques. Methodology: A randomized control was implemented in a public tertiary institution within the Western Cape. Patients admitted for open abdominal surgery via midline incision were eligible for the trial. Participants were randomly allocated to either the control group (CG) receiving conventional post-operative cardio-respiratory physiotherapy, or the intervention group (IG) who received the additional use of the Blow Bottle. Lung function and the development of post-operative pulmonary complications were the primary outcome s of this study. Lung Function was evaluated by means of spirometry testing and interpretation of Forced Expiratory Volume in 1 second (FEV 1) and Forced Vital Capacity (FVC). The development of post-operative pulmonary complications were diagnosed using the criteria by Mackay et al. (2005) where changes from pre-operative findings of auscultation; temperature, X-ray and sputum are evaluated post-operatively and recorded using the Adapted Abdominal Physiotherapy Outcomes Data Sheet (A-APODS). Results: A total of 19 participants were enrolled in the study, n=11 (CG) and n=8 (IG), predominantly female (n=14) and admitted for cancer related abdominal surgery (n=9). There was a statistically significant (p<0.05) marked reduction in post-operative lung function from baseline across groups, 62% in FEV 1 and 47% in FVC on the first post-operative day. The FEV 1 and FVC were similar across both the control and intervention groups for the first three post-operative days. On auscultation majority of participants had decreased breath sounds on the first post-operative day. However, no one participant developed a PPC across the duration of the study as diagnosed using the criteria by Mackay et al. (2005). Conclusion: Whether the additional use of the Blow Bottle is more beneficial than conventional post-operative cardio-physiotherapy alone is inconclusive due to the incremental drop out of participants from the study and small sample size. In this study there was however a significant reduction in lung function post-operatively. This mandates the need for further research investigating the abdominal surgical field and the use of devices to improve lung function, such as the Blow Bottle, as literature is scant and outdated, and sorely lacking in the resource constraint South African hospital settings.

Includes bibliographical references
Purpose: Cardio-respiratory physiotherapy for patients undergoing abdominal surgery has been found to be beneficial in improving lung function post-operatively and in the prevention and treatment of post-operative pulmonary complications (PPCs). The Blow Bottle, a Positive Expiratory Pressure (PEP) therapy device, is commonly used as an adjunct to physiotherapy. The Blow Bottle is low cost and can be easily made by the physiotherapist using readily available materials in the hospital setting. However, evidence to support the use of Blow Bottles in the post-operative management of abdominal surgery is minimal, with few studies reporting significant positive effects especially when compared to conventional cardio-respiratory physiotherapy techniques. Methodology: A randomized control was implemented in a public tertiary institution within the Western Cape. Patients admitted for open abdominal surgery via midline incision were eligible for the trial. Participants were randomly allocated to either the control group (CG) receiving conventional post-operative cardio-respiratory physiotherapy, or the intervention group (IG) who received the additional use of the Blow Bottle. Lung function and the development of post-operative pulmonary complications were the primary outcome s of this study. Lung Function was evaluated by means of spirometry testing and interpretation of Forced Expiratory Volume in 1 second (FEV 1) and Forced Vital Capacity (FVC). The development of post-operative pulmonary complications were diagnosed using the criteria by Mackay et al. (2005) where changes from pre-operative findings of auscultation; temperature, X-ray and sputum are evaluated post-operatively and recorded using the Adapted Abdominal Physiotherapy Outcomes Data Sheet (A-APODS). Results: A total of 19 participants were enrolled in the study, n=11 (CG) and n=8 (IG), predominantly female (n=14) and admitted for cancer related abdominal surgery (n=9). There was a statistically significant (p<0.05) marked reduction in post-operative lung function from baseline across groups, 62% in FEV 1 and 47% in FVC on the first post-operative day. The FEV 1 and FVC were similar across both the control and intervention groups for the first three post-operative days. On auscultation majority of participants had decreased breath sounds on the first post-operative day. However, no one participant developed a PPC across the duration of the study as diagnosed using the criteria by Mackay et al. (2005). Conclusion: Whether the additional use of the Blow Bottle is more beneficial than conventional post-operative cardio-physiotherapy alone is inconclusive due to the incremental drop out of participants from the study and small sample size. In this study there was however a significant reduction in lung function post-operatively. This mandates the need for further research investigating the abdominal surgical field and the use of devices to improve lung function, such as the Blow Bottle, as literature is scant and outdated, and sorely lacking in the resource constraint South African hospital settings.

This thesis deals with the device physics of organic solar cells. Organic photovoltaics (OPV) is a field of applied research which has been growing rapidly in the last decade leading to a current record value of power-conversion efficiency of 10 percent. One major reason for this boom is a potentially low-cost production of solar modules on flexible (polymer) substrate. Furthermore, new application are expected by flexible or semitransparent organic solar cells. That is why several OPV startup companies were launched in the last decade. Organic solar cells consist of hydrocarbon compounds, deposited as ultrathin layers (some tens of nm) on a substrate. Absorption of light leads to molecular excited states (excitons) which are strongly bound due to the weak interactions and low dielectric constant in a molecular solid. The excitons have to be split into positive and negative charges, which are subsequently collected at different electrodes. An effective dissociation of excitons is provided by a heterojunction of two molecules with different frontier orbital energies, such that the electron is transfered to the (electron) acceptor and the positive charge (hole) remains on the donor molecule. This junction can be realized by two distinct layers forming a planar heterojunction or by an intermixed film of donor and acceptor, resulting in a bulk heterojunction. Electrodes are attached to the absorber to collect the charges by providing an ohmic contact in the optimum case. This work focuses on the electrical processes in organic solar cells developing and employing a one-dimensional drift-diffusion model. The electrical model developed here is combined with an optical model and covers the diffusion of excitons, their separation, and the subsequent transport of charges. In contrast to inorganics, charge-carrier mobilities are low in the investigated materials and charge transport is strongly affected by energy barriers at the electrodes. The current-voltage characteristics (J-V curve) of a solar cell reflect the electrical processes in the device. Therefore, the J-V curve is selected as means of comparison between systematic series of simulation and experimental data. This mainly qualitative approach allows for an identification of dominating processes and provides microscopic explanations. One crucial issue, as already mentioned, is the contact between absorber layer and electrode. Energy barriers lead to a reduction of the power-conversion efficiency due to a decrease in the open-circuit voltage or the fill factor by S-shaped J-V curve (S-kink), which are often observed for organic solar cells. It is shown by a systematic study that the introduction of deliberate barriers for charge-carrier extraction and injection can cause such S-kinks. It is explained by simulated electrical-field profiles why also injection barriers lead to a reduction of the probability for charge-carrier extraction. A pile-up of charge carriers at an extraction barrier is confirmed by measurements of transient photocurrents. In flat heterojunction solar cells an additional reason for S-kinks is found in an imbalance of electron and hole mobilities. Due to the variety of reasons for S-kinks, methods and criteria for a distinction are proposed. These include J-V measurements at different temperatures and of samples with varied layer thicknesses. Most of the studies of this this work are based on experimental data of solar cells comprisiing the donor dye zinc phthalocyanine and the acceptor fullerene C60. It is observed that the open-circuit voltage of these devices depends on the mixing ratio of ZnPc:C60. A comparison of experimental and simulation data indicates that the reason is a changed donor-acceptor energy gap caused by a shift of the ionization potential of ZnPc. A spatial gradient in the mixing ratio of a bulk heterojunction is also investigated as a donor(acceptor)-rich mixture at the hole(electron)-collecting contact is supposed to assist charge extraction. This effect is not observed, but a reduction of charge-carrier losses at the “wrong” electrode which is seen at an increase in the open-circuit voltage. The most important intrinsic loss mechanism of a solar cell is bulk recombination which is treated at the example of ZnPc:C60 devices in the last part of this work. An examination of the dependence of the open-circuit voltage on illumination intensity shows that the dominating recombination mechanism shifts from trap-assisted to direct recombination for higher intensities. A variation of the absorption profile within the blend layer shows that the probability of charge-carrier extraction depends on the locus of charge-carrier generation. This results in a fill factor dependent on the absorption profile. The reason is an imbalance in charge-carrier mobilities which can be influenced by the mixing ratio. The work is completed by a simulation study of the influence of charge-carrier mobilities and different recombination processes on the J-V curve and an identification of a photoshunt dominating the experimental linear photocurrent-voltage characteristics in reverse bias
Diese Dissertation beschäftigt sich mit der Physik organischer Solarzellen. Die organische Photovoltaik ist ein Forschungsgebiet, dem in den letzten zehn Jahren enorme Aufmerksamkeit zu Teil wurde. Der Grund liegt darin, dass diese neuartigen Solarzellen, deren aktueller Rekordwirkungsgrad bei 10 Prozent liegt, ein Potential für eine kostengünstige Produktion auf flexiblem (Polymer)substrat aufweisen und aufgrund ihrer Vielfältigkeit neue Anwendungsbereiche für die Photovoltaik erschließen. Organische Solarzellen bestehen aus ultradünnen (einige 10 nm) Schichten aus Kohlenwasserstoffverbindungen. Damit der photovoltaische Effekt genutzt werden kann, müssen die durch Licht angeregten Molekülzustände zu freien Ladungsträgern führen, wobei positive und negative Ladung an unterschiedlichen Kontakten extrahiert werden. Für eine effektive Trennung dieser stark gebundenden lokalisierten angeregten Zustände (Exzitonen) ist eine Grenzfläche zwischen Molekülen mit unterschiedlichen Energieniveaus der Grenzorbitale erforderlich, sodass ein Elektron auf einem Akzeptor- und eine positive Ladung auf einem Donatormolekül entstehen. Diese Grenzschicht kann als planarer Heteroübergang durch zwei getrennte Schichten oder als Volumen-Heteroübergang in einer Mischschicht realisiert werden. Die Absorberschichten werden durch Elektroden kontaktiert, wobei es für effiziente Solarzellen erforderlich ist, dass diese einen ohmschen Kontakt ausbilden, da ansonsten Verluste zu erwarten sind. Diese Arbeit behandelt im Besonderen die elektrischen Prozesse einer organischen Solarzelle. Dafür wird ein eindimensionales Drift-Diffusionsmodell entwickelt, das den Transport von Exzitonen, deren Trennung an einer Grenzfläche und die Ladungsträgerdynamik beschreibt. Abgesehen von den Exzitonen gilt als weitere Besonderheit einer organischen Solarzelle, dass sie aus amorphen, intrinsischen und sehr schlecht leitfähigen Absorberschichten besteht. Elektrische Effekte sind an der Strom-Spannungskennlinie (I-U ) sichtbar, die in dieser Arbeit als Hauptvergleichspunkt zwischen experimentellen Solarzellendaten und den Simulationsergebnissen dient. Durch einen weitgehend qualitativen Vergleich können dominierende Prozesse bestimmt und mikroskopische Erklärungen gefunden werden. Ein wichtiger Punkt ist der schon erwähnte Kontakt zwischen Absorberschicht und Elektrode. Dort auftretende Energiebarrieren führen zu einem Einbruch im Solarzellenwirkungsgrad, der sich durch eine Verringerung der Leerlaufspanung und/oder S-förmigen Kennlinien (S-Knick) bemerkbar macht. Anhand einer systematischen Studie der Grenzfläche Lochleiter/Donator wird gezeigt, dass Energiebarrieren sowohl für die Ladungsträgerextraktion als auch für die -injektion zu S-Knicken führen können. Insbesondere die Tatsache, dass Injektionsbarrieren sich auch negativ auf den Photostrom auswirken, wird anhand von simulierten Ladungsträger- und elektrischen Feldprofilen erklärt. Das Aufstauen von Ladungsträgern an Extraktionsbarrieren wird durch Messungen transienter Photoströme bestätigt. Da S-Knicke in organischen Solarzellen im Allgemeinen häufig beobachtet werden, werden weitere Methoden vorgeschlagen, die die Identifikation der Ursachen ermöglichen. Dazu zählen I-U Messungen in Abhängigkeit von Temperatur und Schichtdicken. Als eine weitere Ursache von S-Knicken werden unausgeglichene Ladungsträgerbeweglichkeiten in einer Solarzelle mit flachem Übergang identifiziert und von den Barrierefällen unterschieden. Weiterer Forschungsgegenstand dieser Arbeit sind Mischschichtsolarzellen aus dem Donator-Farbstoff Zink-Phthalozyanin ZnPc und dem Akzeptor Fulleren C60. Dort wird beobachtet, dass die Leerlaufspannung vom Mischverhältnis abhängt. Ein Vergleich von Experiment und Simulation zeigt, dass sich das Ionisationspotenzial von ZnPc und dadurch die effektive Energielücke des Mischsystems ändern. Zusätzlich zu homogenen Mischschichten werden Solarzellen untersucht, die einen Gradienten im Mischungsverhältnis aufweisen. Die Vermutung liegt nahe, dass ein hoher Donatorgehalt am Löcherkontakt und ein hoher Akzeptorgehalt nahe des Elektronenkontakts die Ladungsträgerextraktion begünstigen. Dieser Effekt ist in dem hier untersuchten System allerdings vergleichsweise irrelevant gegenüber der Tatsache, dass der Gradient das Abfließen bzw. die Rekombination von Ladungsträgern am “falschen” Kontakt reduziert und somit die Leerlaufspannung erhöht. Der wichtigste intrinsische Verlustmechanismus einer Solarzelle ist die Rekombination von Ladungsträgern. Diese wird im letzten Teil der Arbeit anhand der ZnPc:C60 Solarzelle behandelt. Messungen der Leerlaufspannung in Abhängigkeit von der Beleuchtungsintensität zeigen, dass sich der dominierende Rekombinationsprozess mit zunehmender Intensität von Störstellenrekombination zu direkter Rekombination von freien Ladungsträgern verschiebt. Eine gezielte Variation des Absorptionsprofils in der Absorberschicht zeigt, dass die Ladungsträgerextraktionswahrscheinlickeit vom Ort der Ladungsträgergeneration abhängt. Dieser Effekt wird hervorgerufen durch unausgeglichene Elektronen- und Löcherbeweglichkeiten und äußert sich im Füllfaktor. Weitere Simulationsergebnisse bezüglich des Einflusses von Ladungsträgerbeweglichkeiten und verschiedener Rekombinationsmechanismen auf die I-U Kennlinie und die experimentelle Identifikation eines Photoshunts, der den Photostrom in Rückwärtsrichtung unter Beleuchtung dominiert, runden die Arbeit ab

The silky shark Carcharhinus falciformis forms the primary elasmobranch bycatch in tuna purse seine fisheries using fish aggregating devices (FADs) in all of the world’s tropical oceans. Its life-history traits of slow growth, late maturation and low fecundity make it vulnerable to over exploitation, as is apparent from historical bycatch trends. Very little is known about the associative behaviour of this species with floating objects, information which is essential in formulating effective mitigation and management measures. This study aims to address this knowledge gap through the use of various electronic tagging techniques in conjunction with dietary analysis. Dietary data were collected from 323 silky sharks incidentally caught at FADs. Approximately 40 percent of the diet consisted of prey associated with FADs while the remaining 60 percent were non-associated species of crustaceans, cephalopods and fishes. These results suggest that the associative behaviour is not primarily driven by trophic enhancement, but is likely a combination of predator avoidance, social interactions and feeding. Fine-scale behavioural data from silky sharks associated with drifting FADs were collected through the use of acoustic telemetry techniques. Acoustic tags were implanted into 38 silky sharks (69- 116 cm TL) at eight FADs. FADs were equipped with satellite linked acoustic receivers and abandoned to drift freely. Presence/absence and swimming depth data were telemetered via the Iridium satellite system. A total of 300 d of behavioural data were collected from 20 tagged individuals. Individuals remain associated with the same FAD for extended periods (min = 2.84 d, max = 30.60 d, mean = 15.69 d). Strong diel patterns were observed in both association and swimming depth. Typically individuals moved away from FADs after sunset and return later during the night, then remain closely associated until the following evening. Vertical behaviour also changed around sunset with sharks using fairly constant depths, within the upper 25 m, during the day and switching to rapid vertical movements during the night, with dives in excess of 250 m recoded. Broader scale movement behaviour was investigated using pop-up archival satellite tags (PSATs). Tags were deployed on 46 silky sharks (86-224.5 cm TL) for a total of 1495 d. Light data were used to calculate geolocation estimates and reconstruct the sharks’ trajectories. Movement patterns differed between animals and according to deployment duration. Several extensive horizontal movements were observed, with an average track length of 3240 km during an average tag deployment of 44.02 d. Horizontal movement patterns were found to correlate very closely with drift patterns of FADs. Consequently, it appears that the movement behaviour of juvenile silky sharks is strongly influenced by the movement of drifting FADs in this region. Ghost fishing of silky sharks through entanglement in FADs was also investigated using data derived from PSATs as well as underwater visual censuses. Thirteen per cent of the tagged sharks became entangled in FADs and entangled sharks were observed in 35 percent of the 51 FADs surveyed. Using this information in conjunction with estimated time that sharks remained entangled in the FAD (from depth data from PSATs), and scaling up according to estimates of FAD numbers, it was found that between 480 000 and 960 000 silky sharks are killed annually in this manner in the Indian Ocean. Subsequent management measures in this region prevent the deployment of FADs with netting that could lead to entanglement. Overall, floating objects appear to play a significant role in the juvenile life stages of silky sharks in this region. While their association with floating objects is clearly advantageous in an evolutionary sense, under current tuna fishery trends, this behaviour is certainly detrimental for the population.

Cadmium sulfide (CdS) and cadmium telluride (CdTe) are two leading semiconductor materials used in the fabrication of thin film solar cells of relatively high power conversion efficiency and low manufacturing cost. In this work, CdS/CdTe solar cells with a varying set of processing parameters and device designs were fabricated and characterized for comparative evaluation. Studies were undertaken to elucidate the effects of (i) each step in fabrication and (ii) parameters like thickness, sheet resistance, light absorptivity solution concentration, inert gas pressure etc. Best results were obtained when the thickness of CdS planar film for the window layer was in the range of 150 nm to 200 nm. Also, CdS nanowires were fabricated for use as the window layer in CdS-CdTe solar cells. Their materials characteristics were studied with scanning electron microscopy (SEM) and X-ray Diffraction (XRD). Spectral absorption measurements on the planar CdS films and nanowire CdS layers were performed and results compared. It was established that the nanowire CdS design was superior because its absorption of sunlight was far less than that of planar CdS film, which would lead to enhanced performance in the CdS-CdTe solar cell through higher short circuit current density and higher open circuit voltage. Diode behavior of CdS-CdTe devices on planar CdS and nanowire CdS was analyzed and compared. KEYWORDS: Thin Film Solar Cell, Nanowire, UV Absorption, Open-circuit Voltage, Close Space Sublimation

This study investigated the impact of open heart surgery (Coronary Artery Bypass Graft, Heart Valve Replacement, or Left Ventricular Assist Device placement) on cognition, functional performance, and mood in the three months following surgery. The Montreal Cognitive Assessment (MoCA), Kettle Test (KT), Physical Self Maintenance Scale (PSMS), and Hospital Anxiety and Depression Scale (HD) measured global cognition, functional cognition, functional performance, and mood states, respectively. Thirteen male participants (ages 38 – 75) completed assessments at four time points -- when they were scheduled for surgery, within one week prior to surgery, before hospital discharge after surgery, and three months after surgery. ANOVA analyses were conducted on overall raw mean scores taken at these time points. Correlational analysis compared changes in cognition and functional performance of daily activities for this group. Effect size estimations and power analyses were conducted to estimate sample sizes needed for adequately powered subsequent study. Two measures (KT and PSMS) were adequately powered at 95% for the study sample. Functional cognition as measured by the KT improved significantly after surgery and surpassed baseline within three months after surgery. Functional performance as measured by the PSMS declined significantly after surgery but returned to baseline within three months after surgery. Global cognition as measured by the MoCA did not change, was not correlated with other measures, and was below norms at all time points. Mood states as measured by the HADS did not change and were above norms at all time points. This study had a small sample, only male participants, and one pooled group that did not allow for group comparisons. Two measures were self-reported, which may have impacted results due to responses biases. Despite these limitations, this is one of the first studies to track and compare both cognitive and functional performance changes over time. As such, this study may help practitioners and researchers improve and prioritize assessment and treatment options for individuals with cognitive and functional performance deficits after open heart surgery.

[ES] La neurociencia es un campo que abarca muchas especialidades. El objetivo de esta tesis es subsanar algunas carencias tecnológicas que existen en los métodos actuales de experimentación animal en neurociencia. En esta tesis, se presentan seis proyectos, que tendrán como objetivo mejorar el "Principio de las tres R", el cual fue enunciado por los biólogos ingleses W. M. S. Russell y R. L. Burch, durante la experimentación animal. El comportamiento es uno de los aspectos más importantes de la vida animal. Depende de los vínculos entre los animales, sus sistemas nerviosos y sus entornos. Para estudiar el comportamiento de los animales de laboratorio, se necesitan varias herramientas, pero una herramienta de seguimiento es esencial para llevar a cabo un estudio de comportamiento exhaustivo. Varias herramientas de seguimiento visual están actualmente disponibles. Sin embargo, todas tienen algunos inconvenientes. Por ejemplo, en una situación en la que un animal está dentro de una madriguera o cerca de otros animales, las cámaras de rastreo (tracking) no siempre pueden detectar la ubicación precisa o el movimiento del animal. Por esta razón, los entornos enriquecidos para intentar recrear el hábitat natural de los animales en experimentación no pueden utilizarse, ya que los datos recopilados son insuficientes/inexactos. Con la finalidad de mejorar los experimentos de tracking RFID Assisted Tracking Tile (RATT) es presentado en esta tesis. RATT es un sistema de seguimiento basado en tecnología de identificación pasiva de radiofrecuencia (RFID) y está compuesto por baldosas electrónicas con las que se puede construir una gran superficie, sobre la cual los animales pueden moverse libremente. Esto permite la identificación más precisa de los animales, así como el seguimiento de sus movimientos. Este sistema, que también se puede combinar con un sistema de seguimiento con cámaras, allana el camino para estudios completos de comportamiento en entornos enriquecidos. Dada la capacidad de rastrear animales y, por lo tanto, realizar experimentos de comportamiento exhaustivos, es posible observar cómo se comportan los sujetos desde un punto de vista externo. Sin embargo, si queremos comprender lo que sucede en el cerebro de estos sujetos, es necesario aplicar otras técnicas de análisis, por ejemplo, el estudio de señales dependientes del nivel de oxígeno en la sangre (BOLD, por sus siglas en inglés). Las señales BOLD se basan en las respuestas vasculares a la activación neuronal y se utilizan ampliamente en estudios de investigación clínicos y preclínicos. En entornos preclínicos, los animales suelen ser anestesiados. Sin embargo, los anestésicos causan cambios en la fisiología de los animales, p. Ej. hipotermia, y esto tiene el potencial de alterar las señales funcionales de MRI (fMRI). Para evitar la hipotermia en roedores anestesiados, se presenta TherMouseDuino. Este es un sistema de control automático de temperatura de código abierto, que reduce las fluctuaciones de la temperatura, lo que proporciona condiciones sólidas para realizar experimentos de resonancia magnética funcional. En los cursos de biología y neurociencia, la anatomía del cerebro se enseña generalmente utilizando imágenes de resonancia magnética (IRM) o secciones histológicas de diferentes planos. Estos muestran las áreas macroscópicas más importantes en el cerebro de un animal. Sin embargo, este método no es dinámico ni intuitivo. En esta tesis se presenta un cerebro de rata impreso en 3D con fines educativos. La manipulación manual de la estructura, facilitada por la ampliación de sus dimensiones, junto con la capacidad de desmontar el "cerebro" en algunas de sus partes principales, facilita la comprensión de la organización 3D del sistema nervioso. Este es un método alternativo y mejorado para enseñar a los estudiantes en general y a los biólogos, en particular, la anatomía del cerebro de rata.
[CAT] La neurociència és un camp que abasta moltes especialitats. L'objectiu d'aquesta tesi és esmenar algunes manques tecnològiques que existeixen en els mètodes actuals d'experimentació animal en neurociència. En aquesta tesi, es presenten sis projectes, que tindran com a objectiu millorar el "Principi de les tres R", el qual va ser enunciat pels biòlegs anglesos W. M. S. Russell i R. L. Burch, durant l'experimentació animal. El comportament és un dels aspectes m'és importants de la vida animal. Depèn dels vincles entre els animals, els seus sistemes nerviosos i els seus entorns. Per estudiar el comportament dels animals de laboratori, es necessiten diverses eines, però` una eina de seguiment és essencial per a dur a terme un estudi de comportament exhaustiu. Diverses eines de seguiment visual estan actualment disponibles. No obstant això, totes tenen alguns inconvenients. Per exemple, en una situació en la qual un animal esta` dins d'un cau o prop d'altres animals, les cambres de rastreig (tracking) no sempre poden detectar la ubicació precisa o el moviment de l'animal. Per aquesta raó, els entorns enriquits per a intentar recrear l'hàbitat natural dels animals en experimentació no poden utilitzar-se, ja que les dades recopilades són insuficients/inexactes. Amb la finalitat de millorar els experiments de tracking/seguiment RFID Assisted Tracking Tile (RATT) és presentat en aquesta tesi. RATT es un sistema de seguiment basat en tecnologia d'identificació passiva de radiofreqüència (RFID) i esta` compost per rajoles electròniques amb les quals es pot construir una gran superfície, sobre la qual els animals poden moures lliurement. Això permet la identificació més precisa dels animals, així com el seguiment dels seus moviments. Aquest sistema, que també es pot combinar amb un sistema de seguiment amb cambres, aplana el camí per a estudis complets de comportament en entorns enriquits. Donada la capacitat de rastrejar animals i, per tant, realitzar experiments de comportament exhaustius, és possible observar com es comporten els subjectes des d'un punt de vista extern. No obstant això, si volem comprendre el que succeeix en el cervell d'aquests subjectes, és necessari aplicar altres tècniques d'anàlisis, per exemple, l'estudi de senyals dependents del nivell d'oxigen en la sang (BOLD, per les seues sigles en anglès). Els senyals BOLD es basen en les respostes vasculars a l'activació neuronal i s'utilitzen àmpliament en estudis d'investigació clínics i preclínics. En entorns preclínics, els animals solen ser anestesiats. No obstant això, els anestèsics causen canvis en la fisiologia de els animals, per exemple hipotèrmia, i això te el potencial d'alterar els senyals funcionals de MRI (fMRI). Per a evitar la hipotèrmia en rosegadors anestesiats, es presenta TherMouseDuino. Aquest és un sistema de control automàtic de temperatura de codi obert, que redueix les fluctuacions de la temperatura, la qual cosa proporciona condicions solides per a realitzar experiments de ressonància magnètica funcional. En els cursos de biologia i neurociència, l'anatomia del cervell s'ensenya generalment utilitzant imatges de ressonància magnètica (IRM) o seccions histològiques de diferents plans. Aquests mostren les àrees macroscòpiques més importants en el cervell de un animal. No obstant això, aquest mètode no és dinàmic ni intuïtiu. En aquesta tesi es presenta un cervell de rata imprès en 3D amb finalitats educatius. La manipulació manual de l'estructura, facilitada per l'ampliació de les seues dimensions, juntament amb la capacitat de desmuntar el "cervell" en algunes de les seues parts principals, facilita la comprensió de l'organització 3D del sistema nerviós. Aquest és un mètode alternatiu i millorat per a ensenyar a els estudiants en general i als biòlegs, en particular, l'anatomia del cervell de rata.
[EN] Neuroscience is a field that covers many specialties. The objective of this thesis is to correct some technological deficiencies that exist in current methods of animal experimentation in neuroscience. In this thesis, six projects are presented, which will aim to improve the "Principle of the three Rs" in animal experimentation enunciated by the English biologists W. M. S. Russell and R. L. Burch. In the present era of impressive progress in neuroscience, it is still not arguable that a complete understanding of the brain cannot be possible without a comparable understanding of animal behavior. In order to study the behavior of laboratory animals, various tools are needed, being a reliable tracking system one of the most important to follow large populations of individual subjects that interact in complex manners. Several visual tracking tools are currently available. However, they all have some drawbacks. For example, in a situation where an animal is inside a cave, or is in close proximity to other animals, tracking cameras cannot always detect the precise location or movement of the animal. For this reason, environments that have been enriched in order to attempt to recreate the natural habitat of the animals under experiment, cannot be used, as the data gathered is insufficient/inaccurate. In order to improve the current tracking systems , the RATT is presented. RATT is a tracking system based on passive RFID technology and it is composed of electronic tiles. Using several tiles, a large surface area, on which the animals can move freely, can be built. This enables the more accurate identification of the animals, as well as the tracking of their movements. This system, which can also be combined with a visual tracking system, paves the way for complete behavioral studies in enriched environments. Given the ability to track animals and thus conduct thorough behavioral experiments, it is possible to observe how the subjects behave from an external viewpoint. However, if we want to understand what is going on in the brains of these subjects, it is necessary to apply other analysis techniques, for example the study of BOLD signals. BOLD signals are based on vascular responses to neuronal activation and are used extensively in clinical and preclinical research studies. In preclinical settings, animals are usually anesthetized. However, anesthetics cause changes in the physiology of the animals, e.g. hypothermia, and this has the potential to disrupt fMRI signals. In order to avoid hypothermia in anesthetized rodents, TherMouseDuino is presented. This is an Open-Source automatic temperature control system, which reduces temperature fluctuations, thus providing robust conditions in which to perform fMRI experiments. In biology and neuroscience courses, brain anatomy is generally taught using MRI or histological sections of different planes. These show the most important macroscopic areas in an animals' brain. However, this method is neither dynamic nor intuitive. An anatomical 3D printed rat brain with educative purposes is presented in this thesis. Hand manipulation of the structure, facilitated by the scaling up of its dimensions, together with the ability to dismantle the "brain" into some of main its constituent parts, facilitates the understanding of the 3D organization of the nervous system. This is an alternative and improved method for teaching students in general and biologists, in particular, the rat brain anatomy.
This work was supported in part by the Spanish Ministerio de Economía y Competitividad (MINECO) and FEDER funds under grants BFU2015-64380-C2-2-R (D.M.) and BFU2015-64380-C2-1-R, by EU Horizon 2020 Program 668863-SyBil-AA grant (S.C.). S.C. acknowledges financial support from the Spanish State Research Agency, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (ref. SEV-2013-0317) and by a grant “Ayudas para la formación de personal investigador (FPI)” from the Vicerrectorado de Investigación, Innovación y Transferencia of the Universitat Politècnica de València.
Quiñones Colomer, DR. (2019). Developing preclinical devices for neuroscience research in the fields of animal tracking, fMRI acquisition, and 3D histology cutting [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/118795
TESIS

In the last decade, there has been an increase in the number of web-enabled mobile devices, offering a new platform that can be targeted for the development of learning applications. Worldwide, developers have taken initiatives in developing mobile learning (M-learning) systems to provide students with access to learning materials regardless of time and location. The purpose of this study was to investigate whether it is viable for first year students enrolled at the University of Namibia (UNAM) to use mobile phones for ad-hoc learning of mathematical concepts. A system, EnjoyMath, aiming to assist students in preparing for tests, examinations, review contents and reinforce knowledge acquired during traditional classroom interactions was designed and implemented. The EnjoyMath system was designed and implemented through the use of the Human Centred Design (HCD) methodology. Two revolutions of the four-step process of the HCD cycle were completed in this study. Due to the distance between UNAM and Rhodes University (where the researcher was based), the researcher could not always work in close relation with the UNAM students. Students from the Extended Study Unit (ESU) at Rhodes University were therefore selected in the first iteration of the project due to their proximity to the researcher and their similar demographics to the first year UNAM students, while the UNAM students were targeted in the second iteration of the study. This thesis presents the outcome of the two pre-intervention studies of the first-year students' perceptions about M-learning conducted at Rhodes University and UNAM. The results of the pre-intervention studies showed that the students are enthusiastic about using an M-learning system, because it would allow them to put in more time to practice their skills whenever and wherever they are. Moreover, the thesis presents the different stages undertaken to develop the EnjoyMath system using Open Source Software (PHP and MySQL). The results of a user study (post-intervention) conducted with participants at UNAM, ascertained the participants' perception of the usability of the EnjoyMath system and are also presented in this thesis. The EnjoyMath system was perceived by the participants to be "passable"; hence an M-learning system could be used to compliment an E-learning system at UNAM.

La bioélectronique est un domaine interdisciplinaire qui étudie les interconnexions et les interactions entre entités biologiques (cellules, tissus, organes) et systèmes électroniques,par l’intermédiaire du transducteur adéquat. Pour des cellules ou des tissus excitables (neurones, muscles, ...), le transducteur prend la forme d’une simple électrode, car ces tissus produisent une activité électrique spontanée ou, dans le sens inverse, peuvent être excités par un signal électrique externe. Cette communication bidirectionnelle donne lieu à deux schémas expérimentaux : l’acquisition et la stimulation. L’acquisition consiste à enregistrer, traiter et analyser les bio-signaux alors que la stimulation consiste à appliquer le courant électrique adéquat aux tissus vivants, pour déclencher une réaction. Cette thèse se concentre sur ce dernier point : deux générations de système de stimulation ont été développées, chacune basée sur un circuit intégré spécifique et adaptée à différents contextes applicatifs.Tout d’abord, le cadre scientifique a été celui du projet CENAVEX, axé sur la stimulation électrique fonctionnelle pour réhabiliter la fonction respiratoire, suite à une lésion de la moelle épinière. Ensuite, les objectifs de conception ont été étendus pour couvrir de nouveaux besoins d’application : la surveillance de l’impédance électrique in situ et l’exploration des formes d’onde de stimulation originales. Le premier pourrait être une solution pour suivre la réaction tissulaire après l’implantation d’une électrode, contribuant ainsi à la biocompatibilité à long terme des implants ; le second propose d’aller au-delà dela conventionnelle impulsion biphasique carrée et d’explorer de nouvelles formes d’ondes qui pourraient être plus efficaces en termes de consommation d’énergie, pour un effet physiologique donné.Le travail présenté dans ce manuscrit contribue à la conception, à la fabrication et au test de dispositifs de stimulation innovants. Cela a conduit au développement de deux circuits intégrés et de deux dispositifs de stimulation permettant une stimulation multicanal.Les caractérisations électriques et les validations biologiques, de la faisabilité in vitro aux expériences in vivo, ont été menées et sont décrites dans ce manuscrit
Bioelectronics is a cross-disciplinary field that studies interconnections and interactions between biological entities (cells, tissues, organs) and electronic systems, using the adequate transducer. For excitable cells or tissues (neurons, muscles, . . . ), the transducer takes the form of a simple electrode, as these tissues produce a spontaneous electrical activity or,in the opposite way, may be excited by an external electrical signal. This bi-directional communication gives rise to two experimental schemes: acquisition and stimulation. Acquisition consists in recording, processing and analyzing bio-signals whereas stimulation consists in applying the adequate electrical current to living tissues in order to trigger a reaction. This thesis focuses on the latter: two generations of stimulation systems have been developed, both being centered on an Application Specific Integrated Circuit, and adapted to different application contexts. First, the scientific framework was given by the CENAVEX project, focusing on Functional Electrical Stimulation to rehabilitate the respiratory function, following a Spinal Cord Injury. Then, the design objectives were extended to cover new application needs:in situ electrical impedance monitoring and exploration of original stimulation wave forms.The first one could be a solution to follow the tissue reaction after electrode implantation,hence contributing to long-term biocompatibility of implants; the second one proposes to go further the conventional constant biphasic pulse and explore new wave forms that couldbe most efficient in terms of energy consumption, for a given physiological effect.The work presented in this manuscript is a contribution to the design, fabrication and test of innovative stimulation devices. It leaded to the development of two integrated circuits and two stimulation devices permitting multichannel stimulation. Both electrical characterizations and biological validations, from in vitro feasibility to in vivo experiments, have been conducted and are described in this manuscript

A interoperabilidade entre equipamentos ou aplicativos (software) de tecnologias baseadas em redes de campo (fieldbus) é de suma importância nos sistemas de automação, pois permite a integração dos mesmos, de diferentes fabricantes. A integração é feita por uma linguagem de comunicação comum usada entre as diferentes tecnologias heterogêneas. No nível do software configurador FOUNDATION fieldbus (FF) de dispositivos e de malhas de controle, a linguagem usada para garantir a interoperabilidade entre os dispositivos é provida pela tecnologia de descrição de dispositivos chamada Electronic Device Description (EDD), que é proprietária e de complexo desenvolvimento para o fabricante, definida pela fieldbus Foundation. As tecnologias de software abertas e não-proprietárias têm apresentado um grande crescimento nos últimos anos, em especial a tecnologia eXtensible Markup language (XML), que se tornou mundialmente conhecida devido à integração de aplicativos internet, tornando-os assim interoperáveis uns com os outros. É proposta neste trabalho uma tecnologia de descrição de dispositivos aberta, não-proprietária e de simples desenvolvimento (para o fabricante), baseada na tecnologia XML, que é chamada de Open-EDD (Open Eletronic Device Description). A criação dessa tecnologia engloba a definição da linguagem Open-EDDML (Open Eletronic Device Description Markup Language), a modelagem do XML schema e o projeto e implementação de um interpretador (parser). Para validação dessa tecnologia, é feita a integração da mesma em um configurador real e testes usando dispositivos FF.
The interoperability among devices or software based on fieldbus technologies is becoming increasingly requested and demanded because it allows the integration of devices or software from different manufacturers. The integration is implemented through a common communication language used among the different heterogeneous technologies. In the FOUNDATION fieldbus configurator software is used to provide interoperability among devices a proprietary and complex technology (to be developed by manufacturers), known as Electronic Device Description (EDD) that is defined by the fieldbus Foundation. Meanwhile, open and non-proprietary software technologies have presented a great growth in the last years, especially the eXtensible Markup language (XML) technology, which has became worldwide known due to the integration of internet (heterogeneous) applications. This study proposes a new open, non-proprietary and simple (for manufacturer development) device description based on XML, that is named Open-EDD (Open Electronic Device Description). The creation of this technology includes the definition of the language Open-EDDML (Open Electronic Device Description Markup Language), modeling the XML Schema, projecting and implementing the parser. This technology is validated by integrating it to an existent configurator and testing it using FF devices.

nombre croissant de dispositifs informatiques par le biais de technologies réseaux sans fil basées ou non sur des infrastructures (WLAN, Bluetooth, GSM, GPRS, UMTS). Une des problématiques majeures de l'informatique diffuse est de faire communiquer de façon dynamique, spontanée et transparente ces différents dispositifs entre eux indépendamment de leurs hétérogénéités matérielle et logicielle. Les intergiciels ont été introduits dans cet objectif, cependant étant donné leur diversité, une nouvelle source d'hétérogénéité de plus haut niveau apparaît, notamment au niveau de leur protocole d'interaction. Actuellement, deux méthodes permettent de résoudre ces incompatibilités : la substitution et la traduction de protocoles. La première requiert la conception de nouveaux intergiciels capables de s'adapter en fonction de leur environnement d'exécution afin de résoudre dynamiquement l'hétérogénéité des intergiciels existants. L'avantage de cette méthode est de fournir une interopérabilité dynamique. En revanche, son inconvénient est d'être non transparente : elle crée une nouvelle source d'hétérogénéité entre ces nouveaux intergiciels, et nécessite de développer des applications qui leur sont spécifiques. La seconde méthode, quant à elle, est transparente : elle ne requiert ni la conception de nouveaux intergiciels, ni le développement de nouvelles applications. Cependant, elle reste statique et planifiée contrairement à la précédente méthode. Dans le contexte de l'informatique diffuse, ces deux méthodes sont complémentaires. Notre contribution consiste à combiner ces deux approches. A l'aide des langages de processus, nous proposons, dans un premier temps, une spécification formelle de notre solution qui permet de résoudre l'hétérogénéité des intergiciels quels que soient la spécificité de leurs caractéristiques, de leurs protocoles et de leurs technologies. Dans un second temps, nous présentons deux systèmes, basés sur cette spécification, conçus pour résoudre : (i) les incompatibilités des protocoles de découverte de services, (ii) les incompatibilités des protocoles de communication. Leur particularité est d'assurer une interopérabilité dynamique et transparente sans requérir de modifications des applications et des intergiciels existants. A partir de nos différentes expérimentations, il apparaît que le surcoût de cette solution pour résoudre les incompatibilités de protocoles est raisonnable.

This Master’s thesis deals with design and construction of a wireless security and surveillance system in ZigBee wireless networks (IEEE802.15.4). The design consists of creating a star network topology with intended monitoring of home area via end device boards paired with coordinator board, which provides basic networking functionality. End device is used to send data from a temperature sensor DS1631 and magnetic reed switches to coordinator. ZigBee module ZDM-A1281-A2 made by MeshNetics company embedded on each board contains a micro controller ATMega1281 and a transceiver AT86RF230 working in a 2,4GHz frequency band. System is able to notice of any door or window move actions and too high temperature. The non-fully functional ZigBee stack, which is called an Open MAC software, based on MAC (Media Access Control ) layer and PHY (Physical) layer from MeshNetics, has been used to develop the user software. Open MAC consists of three application samples in C code. One of them was modified by the user for an application of communication between the module and sensors. The same design with module RC2204AT made by Radiocrafts company was tested as well, but it couldn’t be executed. All developed boards have been constructed and tested via Terminal PC program.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Este trabalho apresenta uma nova proposta para sistema de refrigeração com controle dinâmico de temperatura, operando com estrutura de compressor aberto, acionado por motor de indução trifásico com velocidade variável, e estágio de entrada retificador com correção ativa do fator de potência. O estágio de entrada é composto por um retificador Boost monofásico com elevado fator de potência, com duas células entrelaçadas, operando no modo de condução crítica, empregando técnica de comutação não dissipativa e controlado por dispositivo FPGA, associado a um estágio de saída inversor de dois níveis convencional trifásico à IGBT, o qual é controlado por um Processador Digital de Sinais (DSP - Digital Signal Processor). A técnica de comutação não dissipativa para o estágio de entrada é baseada em células ZCS (Zero-current-switching). As principais características do retificador incluem a redução da ondulação da corrente de entrada, redução da ondulação da tensão de saída retificada, utilização de componentes com reduzidos esforços, reduzido volume do filtro de entrada para Interferências Eletromagnéticas (EMI - Electromagnetic Interference), elevado Fator de Potência (FP) e reduzida Distorção Harmônica Total (DHT) da corrente de entrada, atendendo os limites da norma IEC61000-3-2. O controle digital para o estágio de saída inversor foi desenvolvido usando duas diferentes técnicas, incluindo a técnica convencional controle escalar Volts/Hertz (V/Hz) e o controle Vetorial com Orientação pelo Fluxo do estator, com o propósito de verificar a aplicabilidade e a performance dos controles digitais propostos, para o controle contínuo da temperatura, aplicados a um protótipo de sistema de refrigeração.
This work presents a new proposal for refrigeration systems with dynamic control of temperature, working with structure of open compressor, driving a three-phase induction motor with variable speed, and input rectifier with active power factor correction. The proposed system is composed of a single-phase high-power-factor boost rectifier, with two cells in interleaved connection, operating in critical conduction mode, and employing a softswitching technique, controlled by a Field Programmable Gate Array (FPGA), associated with a conventional three-phase IGBT bridge inverter (VSI - Voltage Source Inverter), controlled by a Digital Signal Processor (DSP). The soft-switching technique for the input stage is based on zero-current-switching (ZCS) cells. The rectifier s features include reduction in input current ripple, reduction in output voltage ripple, use of low stress devices, low volume for the EMI input filter, high input power factor (PF), and low total harmonic distortion (THD) in the input current, in compliance with the IEC61000-3-2 standards. The digital controller for the output stage inverter has been developed using two different techniques, the conventional Voltage-Frequency control (scalar V/Hz control), and a simplified stator oriented vector control, in order to verify the feasibility and performance of the proposed digital controls, for continuous temperature control, applied at a refrigerator prototype.