This thesis deals with modifications to the construction of vibration-to-electricity energy converter, which is one of possible solutions to problem of sustainable and stable energy source for wireless sensor supply. Upon the exploration of the present state of this problem, new construction of generator is proposed. The aim of this proposal is to enhance the existing generator properties with respect to retention of its dimensions and its weight. Results obtained by simulations of model with proposed parameters are presented and analysed.

The master´s thesis deals with the design of two-stroke uniflow scavenged motorcycle engine according to patent František Pudil (PV 7018-80) 216305. The engine has been designed for using in off-road sport motorcycles. The objective of this thesis is to design the engine of this conception and to reveal benefits and defects of this concept by using this method. In this thesis the emphasis is put on design of the construction groups which are directly related to unconventional concept of engine. On the other hand, the parts which can be designed conventionally were solved marginally or were not solved at all. In the first part of the thesis there are thoroughly dicsussed expected benefits and disadvantages of this concept. Computational part focuses on valvetrain and porting of engine. Last part deals with design of engine parts.

Using a comparative spatial and temporal analysis on sediment cores from 8 lakes in the Mackenzie River Delta uplands region, NT, Canada, this study assessed how persistent organic pollutant (POP) deposition to lake sediments was affected by: (1) the presence of retrogressive thaw slumps on lake shores; and (2) changes occurring with increased autochthonous primary productivity. POPs examined included polychlorinated biphenyls (PCBs), penta- and hexachlorobenzenes (CBzs), and dichlorodiphenyltrichloroethane and metabolites (DDTs). Surface sediments of slump-affected lakes contained higher total organic carbon (TOC)-normalized POP concentrations than nearby reference lakes unaffected by thaw slumps. Inorganic sedimentation rates were positively related to contaminant concentrations, suggesting that the influx of siliciclastic material reducing organic carbon in slump-affected lake water indirectly results in higher concentrations of POPs on sedimentary organic matter. This explanation was corroborated by an inverse relationship between sedimentary POP concentrations and TOC content of the lake water. Deposition proxies of autochthonous carbon were not significantly correlated to POP fluxes of surface sediments, and historical profile fluctuations did not coincide with variation in POP deposition. Thus this study does not support the contention that algal-derived organic carbon increases the delivery of organic pollutants to sediments (the algal-scavenging hypothesis), as previously proposed for mercury. Higher POP concentrations observed in surface sediments of slump-affected lakes are best explained by simple solvent switching processes of hydrophobic contaminants onto a lower pool of available organic carbon when compared to neighbouring lakes unaffected by thaw slump development.

Using a comparative spatial and temporal analysis on sediment cores from 8 lakes in the Mackenzie River Delta uplands region, NT, Canada, this study assessed how persistent organic pollutant (POP) deposition to lake sediments was affected by: (1) the presence of retrogressive thaw slumps on lake shores; and (2) changes occurring with increased autochthonous primary productivity. POPs examined included polychlorinated biphenyls (PCBs), penta- and hexachlorobenzenes (CBzs), and dichlorodiphenyltrichloroethane and metabolites (DDTs). Surface sediments of slump-affected lakes contained higher total organic carbon (TOC)-normalized POP concentrations than nearby reference lakes unaffected by thaw slumps. Inorganic sedimentation rates were positively related to contaminant concentrations, suggesting that the influx of siliciclastic material reducing organic carbon in slump-affected lake water indirectly results in higher concentrations of POPs on sedimentary organic matter. This explanation was corroborated by an inverse relationship between sedimentary POP concentrations and TOC content of the lake water. Deposition proxies of autochthonous carbon were not significantly correlated to POP fluxes of surface sediments, and historical profile fluctuations did not coincide with variation in POP deposition. Thus this study does not support the contention that algal-derived organic carbon increases the delivery of organic pollutants to sediments (the algal-scavenging hypothesis), as previously proposed for mercury. Higher POP concentrations observed in surface sediments of slump-affected lakes are best explained by simple solvent switching processes of hydrophobic contaminants onto a lower pool of available organic carbon when compared to neighbouring lakes unaffected by thaw slump development.

The eco-epidemiology of bovine tuberculosis (Tb) in wild deer (mainly red deer Cervus elaphus) in New Zealand was investigated. Bovine Tb is caused by Mycobacterium bovis. Specific aims were to clarify the likely routes of infection in deer, and to determine the status of deer as hosts of Tb, the likely rates and routes of inter- and intra-species transmission between deer and other wildlife hosts, the role of deer in spreading Tb, and the likely utility of deer as sentinels of Tb presence in wildlife. As the possum (Trichosurus vulpecula) is the main wildlife host of Tb, the research also included some investigation of transmission routes in possums. Patterns of infection were measured in 994 deer killed between 1993 and 2003. Tb prevalence varied between areas (range 8–36%). Few deer had generalised infection, with 21–68% of infected deer having no visible lesions, depending on the area. The retropharyngeal lymph nodes and oropharyngeal tonsils were commonly infected. No dependent fawns less than 0.75 years old were infected, indicating intra-species transmission is rare in wild deer. Where possums were not controlled, the net (cumulative) force of infection in young (1–4 y) deer was 0.10–0.24 per year in males and 0.09–0.12 per year in females, but much lower in older deer (less than 0.05 per year). Possum control reduced the net force of infection quickly, and eventually to zero. However, Tb persisted in possum-controlled areas through immigration of infected deer and, for almost a decade, through the survival of resident deer infected before possum control. Tb was lost from infected deer at an exponential rate of 0.13 per year, mostly as a result of deer recovering from infection rather than dying from it. Wild deer do die of Tb, but there was no discernible effect on age structure. The occurrence of infection in deer was not linked to the local deer or possum density at their kill sites (i.e. in their home range), but the area-wide prevalence of Tb in deer was closely correlated with Tb levels in possums, which were in turn correlated with area-wide measures of possum density. For wild deer in New Zealand, Tb is a persistent but usually inconsequential disease of the lymphatic system. It is acquired mainly by young independent deer, usually orally via the tonsils, and probably as a result of licking infected possums. Many species fed on deer carrion, including possums. Most possums encountering carrion did not feed on it, but a few fed for long periods. Other scavengers such ferrets (Mustela furo), hawks (Circus approximans), and weka (a hen-sized flightless native bird; Gallirallus australis) fed in a way that probably increased the infectivity of carrion to possums. Commercial deer hunting may have facilitated the historical establishment of Tb in possums. Scavenging (including cannibalism) and interactions with dead and dying possums are identified for the first time as potentially important routes for transmission of Tb to possums, and I develop new hypotheses involving peri- and post-mortem transmission in possums that explain many of the epidemiological patterns that are characteristic of the disease in possum. In continuous native forest, deer home range size averaged 250 hectares for six young females, and over twice that for two males. Over 90% of infected deer are likely to die within 2 km (females) or 6 km (males) of where they acquired Tb, but deer could occasionally carry Tb up to 30 km. Deer will be useful as sentinels, but only where other sentinels are rare, because the force of infection for a deer with a single infected possum in its home range is only 0.004 per year, compared to greater than 0.2 per year for deliberately released pigs. Deer are occasionally capable of initiating new cycles of infection in wildlife, but deer control is not essential to eradicate Tb from wildlife.

This thesis provides the measurements of 222Rn exhalation rates, 210Pb deposition rates and excess 210Pb inventories for locations in and around Ranger Uranium Mine and Jabiru located within Kakadu National Park, Australia. Radon-222 is part of the natural 238U series decay chain and the only gas to be found in the series under normal conditions. Part of the natural redistribution of 222Rn in the environment is a portion exhales from the ground and disperses into the atmosphere. Here it decays via a series of short-lived progeny, that attach themselves to aerosol particles, to the long lived isotope 210Pb (T1/2 = 22.3 y). Attached and unattached 210Pb is removed from the atmosphere through wet and dry deposition and deposited on the surface of the earth, the fraction deposited on soils is gradually transported through the soil and can create a depth profile of 210Pb. Here it decays to the stable isotope 206Pb completing the 238U series. Measurements of 222Rn exhalation rates and 210Pb deposition rates were performed over complete seasonal cycles, August 2002 - July 2003 and May 2003 - May 2004 respectively. The area is categorised as wet and dry tropics and it experiences two distinct seasonal patterns, a dry season (May-October) with little or no precipitation events and a wet season (December-March) with almost daily precipitation and monsoonal troughs. November and April are regarded as transitional months. As the natural processes of 222Rn exhalation and 210Pb deposition are heavily influenced by soil moisture and precipitation respectively, seasonal variations in the exhalation and deposition rates were expected. It was observed that 222Rn exhalation rates decreased throughout the wet season when the increase in soil moisture retarded exhalation. Lead-210 deposition peaked throughout the wet season as precipitation is the major scavenging process of this isotope from the atmosphere. Radon-222 is influenced by other parameters such as 226Ra activity concentration and distribution, soil porosity and grain size. With the removal of the influence of soil moisture during the dry season it was possible to examine the effect of these other variables in a more comprehensive manner. This resulted in categorisation of geomorphic landscapes from which the 222Rn exhalation rate to 226Ra activity concentration ratios were similar during the dry season. These results can be extended to estimate dry season 222Rn exhalation rates from tropical locations from a measurement of 226Ra activity concentration. Through modelling the 210Pb budget on local and regional scales it was observed that there is a net loss of 210Pb from the region, the majority of which occurs during the dry season. This has been attributed to the fact that 210Pb attached to aerosols is transported great distance with the prevailing trade winds created by a Hadley Circulation cell predominant during the dry season (winter) months. By including the influence of factors such as water inundation and natural 210Pb redistribution in the soil wet season budgeting of 210Pb on local and regional scales gave very good results.

In the event of a radioactive release in an urban environment the consequent response mustbe swift and precise. As soon as first responders have correct information, they can make anaccurate risk assessment. However, if the position, release rate and time of the radioactiverelease is unknown it is hard to know how the pollutant will spread. This thesis aims to testa model which approximates these three unknowns using weather data (wind and rain) as wellas measurement data collected at sensors placed around an urban environment. An atmospheric dispersion model based on an existing Reynolds Averaged Navier-Stokes modelis set up in two geometries of different complexity to create forward mode synthetic depositiondata and adjoint mode concentration fields resulting from a fixed dry deposition velocity andscavenging effect for wet deposition. Variations of time- and space-dependent rainfall is simu-lated. The resulting data is used in an existing optimization model, where a parameter studyis conducted regarding regularization coefficients. This thesis shows that the optimization model accurately estimates position and its approximaterelease rate of a 2D geometry of radioactive releases using a logarithmic optimization approach,and fail to do so using a linear optimization approach. The logarithmic optimization model alsoapproximately estimates position and release rate in a 3D geometry. Regularization parametersshould be within the range of 0.1 and 1.2 depending on rain. More rain requires smallerparameters and will estimate a lower release rate. Time-dependent rainfall is shown to have amajor negative effect on simulation time.iii

Tesis por compendio / [EN] Persimmon (Diospyros kaki L.) 'Rojo Brillante' is an astringent variety characterised by good growing conditions, excellent colour, size, sensory characteristics and good nutritional properties. In the last decade, its production has grown substantially in Spain given the application of high levels of CO2 to remove astringency while firmness is preserved. This technology has also increased its potential as a fresh-cut commodity. However, physical damage during processing result in degradation of the colour and firmness of the product and a higher susceptibility to microbial spoilage that significantly reduces the fruit's shelf life. The objective of the present thesis was to develop optimum procedures for processing and marketing 'Rojo Brillante' persimmon into a fresh-cut product with the maximum shelf life and best physicochemical, nutritional, sensory and microbiological quality. Firstly, the objective was to evaluate the effect of the maturity stage (MS) at harvest, storage time at 15 ºC before processing, and the application of different antioxidant treatments on enzymatic browning, sensory and nutritional quality of fresh-cut 'Rojo Brillante' persimmon during storage at 5 ºC. Concentrations of 10 g L-1 ascorbic acid (AA) or 10 g L-1 citric acid (CA) controlled tissue browning and maintained the visual quality of fresh-cut persimmon above the limit of marketability for 6-8 storage days at 5 ºC, depending on the MS. However, these acidic solutions reduced fruit firmness as compared to control samples. Further studies showed that the combination of these antioxidants with 10 g L-1 CaCl2 maintained firmness of the persimmon slices within the same range as the control samples. In another work, the application of 1-methylcyclopropene (1-MCP) allowed to process fruits after 45 days of storage at 1 ºC with commercial firmness and the antioxidant solution (10 g L-1 CA + 10 g L-1 CaCl2) extended the limit of marketability up to 9 days of storage at 5 ºC. Different controlled atmosphere conditions in combination with AA or CA dips were also evaluated as a first step to select optimum O2 and CO2 concentrations for modified atmosphere packaging (MAP) of fresh-cut 'Rojo Brillante' persimmons. Overall, the combination of antioxidant dips and a controlled atmosphere composed of 5 kPa O2 (balance N2) was proved to be the most effective combination to control enzymatic browning. This atmosphere maintained the visual quality of persimmon slices within the limit of marketability during 7- 9 days at 5 ºC. On the contrary, high CO2 concentrations (10 or 20 kPa) induced darkening in some tissue areas, associated with a flesh disorder known as 'internal flesh browning'. Later studies confirmed the beneficial effect of an active MAP in 5 kPa O2 compared to passive MAP to improve the visual quality of fresh-cut 'Rojo Brillante' persimmon, showing a synergic effect with the antioxidant dip (10 g L-1 CA + 10 g L-1 CaCl2). Antioxidant edible coatings were prepared from whey protein isolate (WPI), soy protein isolate (SPI), hydroxylpropyl methylcellulose (HPMC) and apple pectin as the polymeric matrix. All edible coatings were amended with the antioxidant combination selected (10 g L-1 CA + 10 g L-1 CaCl2). All the edible coatings tested proved effective to control enzymatic browning of persimmon slices. However, the samples treated with the HPMC- and pectin- based coatings were scored with a better visual quality that the rest of the treatments. In general, free radical scavenging activity and total carotenoid content increased in late-season persimmons; whereas, processing (cutting and storage at 5 ºC), antioxidant dips, controlled atmosphere storage or edible coatings had no clear effect on nutritional quality (vitamin C, free radical scavenging activity, total phenolic content, and carotenoids) of fresh-cut persimmons. / [ES] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' es un cultivar astringente que presenta unas propiedades organolépticas y nutricionales excelentes. En la última década, su cultivo en el área mediterránea de España se ha incrementado de manera exponencial con el desarrollo de la tecnología que permite eliminar la astringencia, manteniendo la firmeza del mismo. Esta nueva forma de presentación, aporta numerosas ventajas, entre la que se incluye la posibilidad de ser comercializado como fruta fresca cortada. Sin embargo, el éxito comercial del producto está limitado por el pardeamiento enzimático, la pérdida de firmeza y al crecimiento microbiano. En este contexto, el objetivo de la Tesis ha sido el desarrollo de caqui 'Rojo Brillante' fresco cortado mediante un enfoque que integra el estudio de las características del producto en el momento del procesado y de distintas tecnologías que mantengan la calidad físico-química, sensorial, nutricional y microbiológica del producto durante un periodo que permita su comercialización. En primer lugar, se evaluó el efecto del estado de madurez (MS) en el momento de recolección, el tiempo de almacenamiento a 15 ºC antes del procesado y la aplicación de diferentes antioxidantes en el pardeamiento enzimático y la calidad sensorial y nutricional del caqui 'Rojo Brillante' cortado y almacenado a 5 ºC. La aplicación de 10 g L-1 de ácido ascórbico (AA) ó 10 g L-1 ácido cítrico (CA) controló el pardeamiento enzimático y mantuvo la calidad visual del caqui por encima del límite de comercialización entre 6 y 8 días de almacenamiento a 5 ºC, dependiendo del MS. Sin embrago, la aplicación de estos antioxidantes redujo de manera significativa la firmeza del fruto respecto al control. La combinación de estos antioxidantes con 10 g L-1 de CaCl2 permitió mantener la firmeza en el mismo rango que las muestras control. En un trabajo posterior, la aplicación de 1-metilciclopropeno (1-MCP) permitió procesar caqui almacenado 45 días a 1 ºC con una buena firmeza comercial y el tratamiento antioxidante (10 g L-1 CA + 10 g L-1 CaCl2) consiguió alcanzar un límite de comercialización del producto de 9 días a 5 ºC. La evaluación de distintas atmósferas controladas en combinación con tratamientos antioxidantes (AA o CA), como paso previo al envasado en atmósfera modificada (MAP) del caqui, mostró como más efectiva en el control del pardeamiento enzimático la atmósfera compuesta por 5 kPa O2 (balance N2). Esta atmósfera mantuvo la calidad visual del caqui cortado dentro del límite de comercialización durante 7-9 días a 5 ºC. Por el contrario, la aplicación de altas concentraciones de CO2 (10 ó 20 kPa) dio lugar a un pardeamiento en ciertas zonas de la pulpa que se conoce como 'internal flesh browning'. Estudios posteriores confirmaron el efecto beneficioso del envasado de caqui cortado y tratado con solución antioxidante (CA-CaCl2) en una MAP activa de 5 kPa O2 en la calidad visual del fruto frente a la aplicación de una MAP pasiva. El desarrollo de recubrimientos comestibles con capacidad antioxidante se realizó mediante la incorporación de antioxidantes (10 g L-1 CA + 10 g L-1 CaCl2) a formulaciones a base de proteína de suero lácteo (WPI), proteína de soja (SPI), hidroxipropilmetilcelulosa (HPMC) y pectina. Todos los recubrimientos fueron efectivos controlando el pardeamiento enzimático del caqui cortado, siendo las muestras recubiertas con HPMC y pectina las mejor evaluadas visualmente. En general, el procesado, la aplicación de antioxidantes, el envasado en atmósferas controladas y los distintos recubrimientos comestibles estudiados, si bien no mostraron un efecto claro en los parámetros de calidad nutricional evaluados, no tuvieron un efecto negativo en los mismos. Por otra parte, los frutos cosechados a final de campaña tuvieron mayor actividad antioxidante y contenido en carotenoides. / [CA] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' és un cultiu astringent que presenta unes propietats organolèptiques i nutricionals excel¿lents. En la última dècada, el seu cultiu en l'àrea mediterrània d'Espanya s'ha incrementat de manera exponencial amb el desenvolupament de la tecnologia que permet eliminar l'astringència, mantenint la fermesa del mateix. Esta nova forma de presentació, aporta un gran nombre d'avantatges, entre els quals s'inclou la possibilitat de comercialitzar-lo com fruita fresca processada. No obstant, l'èxit comercial del producte està limitat per pardetjament enzimàtic, la pèrdua de fermesa i el creixement microbià. L'objectiu de la Tesis ha estat en el desenvolupament de caqui 'Rojo Brillante' tallat en fresc mitjançant un enfocament que integra l'estudi de les característiques del producte en el moment del processat i de diferents tecnologies en el manteniment de la qualitat físico-química, sensorial, nutricional i microbiològica del producte durant un període que permeta la seua comercialització. En primer lloc, es va avaluar l'efecte de l'estat de maduresa (MS) en el moment de recol¿lecció, el temps d'emmagatzemament a 15ºC abans del processat i l'aplicació de diferents tractaments antioxidants en el pardetjament enzimàtic i la qualitat sensorial i nutricional del caqui 'Rojo Brillante' tallat i emmagatzemat a 5 ºC. L'aplicació de 10 g L-1 d'àcid ascòrbic (AA) o 10 g L-1 d'àcid cítric (CA) va controlar el pardetjament enzimàtic i va mantenir la qualitat visual del caqui per damunt del límit de comercialització entre 6-8 dies d'emmagatzemament a 5 ºC, depenent del MS. No obstant, l'aplicació d'antioxidants va reduir de manera significativa la fermesa del fruit comparat amb el control. La combinació d'aquestos antioxidants amb 10 g L-1 de CaCl2 va permetre mantenir la fermesa en el mateix rang que les mostres control. En un treball posterior, l'aplicació de 1-metilciclopropeno (1-MCP) va permetre processar caqui emmagatzemat 45 dies a 1 ºC amb una bona fermesa comercial i a més, el tractament antioxidant (10 g L-1 CA + 10 g L-1 CaCl2) va aconseguir un límit de comercialització del producte tallat de 9 dies a 5 ºC. L'avaluació de diferents atmosferes controlades en combinació amb tractaments antioxidants (AA o CA), com a pas previ a l'envasament en atmosfera modificada (MAP) del caqui 'Rojo Brillante, va mostrar com a més efectiva en el control del pardetjament enzimàtic l'atmosfera composta per 5 kPa O2 (balanç N2). Aquesta atmosfera va mantenir la qualitat visual del caqui tallat dins del límit de comercialització durant 7-9 dies a 5 ºC. Per contra, l'aplicació d'altes concentracions de CO2 (10 ó 20 kPa) va donar lloc a un pardetjament en certes zones de la polpa, el qual és conegut com 'internal flesh browning'. Estudis posteriors van confirmar l'efecte beneficiós de l'envasament de caqui tallat i tractat amb solució antioxidant (CA-CaCl2) en una MAP activa de 5 kPa O2 millorant la qualitat visual de la fruita front a l'aplicació de una MAP passiva. El desenvolupament de recobriments comestibles amb capacitat antioxidant es va realitzar mitjançant la incorporació d'antioxidants (CA-CaCl2) en formulacions a base de proteïna de sèrum làctic (WPI), proteïna de soia (SPI), hidroxipropilmetilcel-lulosa (HPMC) i pectina. Tots els recobriments van ser efectius controlant el pardetjament enzimàtic del caqui tallat. No obstant, les mostres recobertes amb HPMC i pectina van ser millor avaluades visualment que la resta de tractaments. En general, el processat, l'aplicació d'antioxidants, l'envasament en atmosferes controlades i els distints recobriments comestibles estudiats, si bé no van mostrar un efecte clar en els paràmetres de la qualitat nutricional avaluats, no van tindre un efecte negatiu en els mateixos. Per altra banda, els fruits recol¿lectats a final de temporada van tenir major activitat antioxidant i contingut en / Sanchís Soler, E. (2016). Effect of processing on the physicochemical, sensory, nutritional and microbiological quality of fresh-cut 'Rojo Brillante' persimmon [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62588 / Compendio

<div>A growing global population and improved standard of living in developing countries have resulted in an unprecedented increase in energy demand over the past several decades. While renewable energy sources are increasing, a huge portion of energy is still converted into useful work using heat engines. The combustion process in diesel and petrol engines releases carbon dioxide and other greenhouse gases as an unwanted side-effect of the energy conversion process. By improving the efficiency of internal combustion engines, more chemical energy stored in petroleum resources can be realized as useful work and, therefore, reduce global emissions of greenhouse gases. This research focused on improving the thermal efficiency of opposed-piston engines, which, unlike traditional reciprocating engines, do not use a cylinder head. The cylinder head is a major source of heat loss in reciprocating engines. Therefore, the opposed-piston engine has the potential to improve overall engine efficiency relative to inline or V-configuration engines.</div><div><br></div>The objective of this research project was to further improve the design of opposed-piston engines by using computational fluid dynamics (CFD) modeling to optimize the engine geometry. The CFD method investigated the effect of intake port geometry and exhaust piston lead angle on the scavenging process and in-cylinder turbulence. After the CFD data was analyzed, scavenging efficiency was found insensitive to transfer port geometry and exhaust piston lead angle with a maximum change of 0.61%. Trapping efficiency was altered exclusively by exhaust piston lead angle and changed from 18% to 26% as the lead angle was increased. The in-cylinder turbulence parameters of the engine (normalized swirl circulation, normalized tumble circulation, and normalized TKE) experienced more complex relationships. All turbulence parameters were sensitive to changing transfer port geometry and exhaust piston lead angle. Some examples of trends seen during the analysis include: an increase in normalized swirl circulation from 0.01 to 4.45 due to changes in swirl angle, a change in normalized tumble circulation from -28.52 to 21.11 as swirl angle increased, and an increase in normalized tumble circulation from 14.20 to 33.68 as exhaust piston lead angle was increased. Based on the present work, an optimum configuration was identified for a swirl angle of 15°, a tilt angle of 10°, and an exhaust piston lead angle of 20°. Future work includes expanding the numerical model’s domain to support a complete cylinder-port configuration, adding combustion products to the diffusivity equation in the UDF, and running additional test cases to describe the entire input space for the sensitivity analysis.<br>