This thesis work primarily focuses on the applicability of sub-threshold source coupled logic (STSCL) for building digital circuits and systems that run at very low voltage and promise to provide desirable performance with excellent energy savings. Sectors like bio-engineering and smart sensors require the energy consumption to be effectively very low for long battery life. Alongside meeting the ultra-low power specification, the system must also be reliable, robust, and perform well under harsh conditions. In this thesis work, logic gates are designed and analyzed, using STSCL. These gates are further used for implementation of digital subsystems in small-sized smart dust sensors which would operate at very low supply voltages and consume extremely low power. For understanding the performance of STSCL with respect to ultra-low power and energy; a seven-stage ring oscillator, a 4-by-4 array multiplier, a fifth-order FIR filter and finally a fifty-fifth-order FIR filter were designed. The subcircuits and systems have been simulated for different supply voltages, scaling down to 0.2 V, at different temperature values (-20oC and 70oC) in both 45 nm and 65 nm process technologies. The chosen architectures for the FIR filters and array multiplier were conventional and essentially taken from traditional CMOS-based designs. The simulated results are studied, analyzed and compared with same CMOS-based digital circuits. The results show on the advantage of STSCL-based digital systems over CMOS. Simulation results provide an energy consumption of 1.1388 nJ for a fifty-fifth-order FIR filter, at low temperatures (-20oC), using STSCL logic, which is comparatively less than for the corresponding CMOS logic implementation.

Copper vapour laser (CVL) pumped high repetition rate narrow bandwidth dye laser is an important source of tunable radiation. It finds numerous applications in spectroscopic investigations and selective material processing like atomic vapour laser isotope separation (AVLIS). Being wavelength selective in these applications stability of the output wavelength and bandwidth are extremely important. The stability of these parameters depend upon the refractive index fluctuation of the dye medium, due to pump beam induced temperature gradients, dye solution flow, and mechanical stability of optical components. Precise measurement of wavelength and bandwidth of a dye laser and control over parameters governing the variations are important for any stable dye laser system. In this thesis, details of investigations carried out on a Rhodamine 6G dye laser for obtaining stable wavelength and output power are presented. Parameters that affect the stability were identified, monitored and put on close loop control to achieve the desired stability. Pump beam i.e. CVL optical power, dye flow rate and dye solution temperature are mainly these parameters. CVL power is mainly a function of input electrical power and pressure of the buffer gas inside the tube. To monitor and regulate these parameters, different sensors and actuators were selected and interfaced with a master slave topology based data acquisition and control system. The DAQ and control system is designed around a micro controller card based on advanced CPU P80552 and has on chip 8 channel 10 bit multiplexed analog input, 16 TTL digital inputs and 16 digital outputs. It works as slave and PC as master. Following closed loops were designed and incorporated to maintain a stable output: a. Average output of CVL was maintained constant by regulating the electric input power through closed loop control. b. The buffer gas pressure was monitored with a semiconductor pressure sensor and was regulated using pulse width modulation. c. Temperature of the dye solution was monitored with PT100 and was controlled using proportional controller. d. Flow rate of dye solution was controlled using a variable frequency drive (VFD) for the dye circulation pump. e. The dye laser wavelength was monitored by using a high resolution spectrograph and pixel position of the peak from CCD image obtained from spectrograph is used for feedback correction using a pico motor. In the present work with application of the above-mentioned input power and pressure loops, a stable output of CVL, is achieved. Variations in power and pulse width of CVL are got limited to within 2%, from 10% when CVL system was working unregulated. This control system does the line regulations and corrects the input electrical power if variations in discharge current occur due to pressure variation. Every dye cell has limits on flow rate because of its geometry. With flow and temperature control dye cell was characterized to work with lower linewidth. VFD (variable frequency drive) is used for flow regulation. Finally active control on set wavelength was also achieved with resolution of 0.01nm accuracy. Measurement of wavelength was done with 0.3 m, 0.054 nm resolution spectrograph. Closed loop pico motor with 30 nm per step linear resolution was used for wavelength control. The thesis is organized in four chapters. First chapter presents a brief introduction to high repetition rate CVL pumped dye laser, operation of a CVL and parameters affecting the dye laser stability and their control schemes. Literature survey in this chapter is focused on different control mechanisms used with such lasers. Second chapter describes the laser system and interfacing of data acquisition system used for experimental setup. Closed loop controls for different parameters are described in this chapter. It also describes the software algorithms developed for this work. Third chapter presents experimental results and analysis with discussion on performance of the control loops. Finally the conclusion is given and few suggestions are made for further work.

Detta examensarbete utreder avståndsbedömning med hjälp av bildbehandling och stereoseende för känd kamerauppställning. Idag existerar ett stort antal beräkningsmetoder för att få ut avstånd till objekt, men metodernas prestanda har knappt mätts. Detta arbete tittar huvudsakligen på olika blockbaserade metoder för avståndsbedömning och tittar på möjligheter samt begränsningar då man använder sig av känd kunskap inom bildbehandling och stereoseende för avståndsbedömning. Arbetet är gjort på Bofors Defence AB i Karlskoga, Sverige, i syfte att slutligen användas i ett optiskt sensorsystem. Arbetet utreder beprövade Resultaten pekar mot att det är svårt att bestämma en närmask, avstånd till samtliga synliga objekt, men de testade metoderna bör ändå kunna användas punktvis för att beräkna avstånd. Den bästa metoden bygger på att man beräknar minsta absolutfelet och enbart behåller de säkraste värdena.

This study presents a theoretical GIS model to investigate the relative impacts of geomorphic and environmental factors that govern the occurrence of landslides on the slopes of Mount Cameroon and its surrounding areas. The study area is located along the Cameroon Volcanic Line (CVL), a major structural feature that originates from the south Atlantic and continues into the continental landmass. The quite frequent seismic activity, geologic character, humid tropical climate and high human pressure on hill slopes are the major factors behind the occurrence of landslides in Mount Cameroon. This paper, therefore, underscores the necessity of in-depth follow-up studies concerned with landslides prevention and management based on the relevance of sufficient reliable field methods in landform geomorphology and interpretation. As much is yet to be done to acquire data for structural and surface geology, hydrology, geomorphic processes and physiography of Mount Cameroon, it is difficult at this point in time to considerably apply suitable methods using GIS that would enable identifying and delineating the landslide-prone areas. In addition, the application of environmental surface monitoring instruments will not be meaningful without a clear presentation of which areas are a cause for concern (given that the employment of any slope stability monitoring and rehabilitation efforts will be only possible after appropriate problem-area identification has been done). Consequently, based on the writer’s previous work in the Mount Cameroon area and available related literature, a methodology using GIS is proposed, which provides the capability to demonstrate how the impact of individual or collective geomorphologic site-specific factors on landslides occurrence could be justified. Considering that digital data may not be readily available, a procedure for the creation of data and analysis of themes is proposed and illustrated. The factors analysis approach in landslides analysis may be cheaper and easier to employ in Mount Cameroon and similar problem regions in developing countries (given that there may be problems of limited financial resources and available expertise in GIS technology and applications). The study underscores and recommends the necessity for a later practical implementation with the availability of adequate resources.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-01-10T11:15:29Z No. of bitstreams: 1 lilypaolamartinezabad.pdf: 2623487 bytes, checksum: bd4d6d3010f0286720ab5bcfb393b5ea (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2017-01-31T11:20:52Z (GMT) No. of bitstreams: 1 lilypaolamartinezabad.pdf: 2623487 bytes, checksum: bd4d6d3010f0286720ab5bcfb393b5ea (MD5) / Made available in DSpace on 2017-01-31T11:20:52Z (GMT). No. of bitstreams: 1 lilypaolamartinezabad.pdf: 2623487 bytes, checksum: bd4d6d3010f0286720ab5bcfb393b5ea (MD5) Previous issue date: 2016-09-30 / A leishmaniose visceral canina (LVC) representa um grave problema de saúde pública. No Brasil, a prevalência da infecção nos cães é bastante variável, podendo atingir níveis superiores a 60% em alguns surtos. O teste rápido Dual Path Platform (TRDPP®-Bio-Manguinhos), como teste de triagem, seguido por ELISA (EIE-BioManguinhos), como teste confirmatório, tornaram-se parte do protocolo de diagnóstico da LVC, credenciado no Brasil desde 2011. No entanto, o diagnóstico da LVC ainda precisa ser melhorado para alcançar uma taxa de detecção mais precisa. Recentemente, rKLO8, uma nova proteína antigênica de L. donovani do Sudão foi clonada e purificada, e mostrou alta reatividade para diagnosticar leishmaniose visceral em humanos. O presente estudo teve como objetivo avaliar a reatividade de soros de cães frente ao antígeno rKL08 e o antígeno de referência rK26, comparando ambas as proteínas, utilizadas como antígenos em testes de ELISA, com os testes DPP® e EIE, usados como testes de diagnóstico da LVC. Amostras de soros de cães de Governador Valadares, uma área endêmica para leishmaniose em Minas Gerais, Brasil, foram agrupadas da seguinte forma: (I) DPP®/EIE negativo (n = 100), (II) DPP® positivo / EIE negativo e (III) DPP® / EIE positivo (n = 100). Níveis séricos elevados de IgM e IgG para ambos os antígenos, rKLO8 e rK26, foram encontrados no grupo III (p <0,0001). Interessantemente, foram detectados níveis elevados de IgG2 e baixos níveis de IgG1 contra ambos os antígenos no grupo de cães DPP®/EIE positivo, sugerindo a ocorrência de um fenótipo predominantemente do tipo Th1 associado com infecção subclínica. O ELISA-rKLO8 (IgG) e o ELISA-rK26 (IgG) mostraram uma sensibilidade de 68% e 77%, e especificidade de 92% e 91%, respectivamente, determinado através da análise da curva ROC. Além disso, o coeficiente Kappa indicou boa concordância (0,739) entre o ELISA-rKLO8 versus o ELISA-rK26. Ainda, a combinação de antígenos rKLO8 e rK26 (rKLO8+rK26) em um mesmo teste exibiu maior sensibilidade (85%) e especificidade (93%). A análise kappa mostrou que o ELISA-rKLO8 + rK26 (IgG) teve melhor concordância com ambos os testes, DPP® e EIE, com valores de kappa igual a 0,700. Estes dados indicaram que a combinação dos antígenos rKLO8 e rK26 gera uma melhor acurácia no diagnóstico da LVC que os antígenos rKLO8 e rK26 usados em separado na detecção de IgG. Estes resultados demonstraram, pela primeira vez, a utilidade do antígeno rKLO8 no diagnóstico da LVC, e que ELISA-rKLO8, pode representar uma potencial ferramenta adicional para o diagnóstico de LVC. / Canine Visceral Leishmaniasis (CVL) represents a serious public health issue. In Brazil, the prevalence of infection in dogs is quite variable and may reach levels above 60% in some outbreaks. The dual Path Platform (DPP®-Bio-Manguinhos) as quick screening test followed by ELISA (EIE-Bio-Manguinhos) as a confirmatory test became part of the diagnostic protocol of CVL, nationally accreditated in Brazil since 2011. However, CVL diagnosis still needs to be improved to achieve a more accurate detection rate. Recently, rKLO8, a new antigenic protein of Sudanese L. donovani, was cloned and purified and had high reactivity to diagnose human VL. The present study aimed to evaluate serum reactivity to rKL08 and to the reference antigen rK26, and to compare both diagnostic proteins used in ELISA with the combined DPP® and EIE as diagnostic tests of CVL. Dog sera samples from Governador Valadares, an area endemic for leishmaniasis in Minas Gerais, Brazil, were grouped in the following way: (I) DPP®/EIE negative (n = 100), (II) DPP® positive/EIE negative and (III) DPP®/EIE positive dog sera (n = 100). Enhanced serum levels of IgM and IgG to both rKLO8 and rK26 were found in group III (p<0.0001). Interestingly, high IgG2 and low IgG1 levels against both antigens were detected in DPP®/EIE positive dogs, suggesting the occurrence of a predominant Th1 phenotype associated with subclinical infection. The rKLO8-ELISA (IgG) and the rK26-ELISA (IgG) showed a sensitivity of 68% and 77% and specificity of 92% and 91%, respectively, determined by ROC curve analysis. In addition, Kappa coefficient indicated good agreement (0.739) between rKLO8-ELISA and rK26-ELISA. Moreover, the combination of rKLO8 and rK26 antigens (rKLO8+rK26) exhibited higher sensitivity (85%) and specificity (93%). Kappa analysis established that rKLO8+rK26-ELISA (IgG) had better agreement with both DPP® and EIE, with kappa values of 0.700. These data indicate that the combination of rKLO8 and rK26 antigens has better accuracy in the diagnosis of CVL than rKLO8 and rK26 used separately at detecting IgG. These results showed for the first time the usefulness of rKLO8 antigen in the diagnosis of CVL, and that rKLO8-ELISA may represent a potential additional tool for the diagnosis of CVL.