Conselho Nacional de Desenvolvimento Científico e Tecnológico / The importance of hybrid rice is increasing because of its higher potential yield compared to n conventional varieties traditionally sown in southern Brazil. The SimulArroz model is a dynamic deterministic mathematical model that simulates the growth, development and grain yield in rice, but the current version of SimulArroz (version 1.0) does not contain the option for hybrid rice. The objective of this dissertation was to calibrate and evaluate the performance of SimulArroz model in simulating the number of leaves, phenology, dry matter accumulation and grain yield of three hybrid rice cultivars in Rio Grande do Sul State, Brazil. Field experiments were conducted in Santa Maria, and in research stations of the Instituto Rio Grandense do Arroz in Cachoeirinha, Uruguaiana, Santa Vitória do Palmar, Cachoeira do Sul, Bagé and Camaquã. The number of main stem leaves, based on the Haun scale, and phenology, based on the Counce scale, and also, plant samples were collected in Santa Maria and Cachoeirinha to determine the dry matter of shoots, leaves, culms, senescent leaves and grain yield. The SimulArroz model is calibrated and evaluated to simulate the number of leaves on the main stem, represented by Haun Stage, phenology, the total dry matter above ground, leaves, stems, senescent leaves and grain yield at 13 % moisture of three hybrid rice cultivars in Rio Grande do Sul. / O arroz híbrido vem ganhando importância por apresentar um potencial produtivo maior do que as cultivares convencionais tradicionalmente semeadas no Sul do Brasil. O modelo SimulArroz é um modelo matemático dinâmico determinístico que simula o crescimento, o desenvolvimento e a produtividade de grãos na cultura do arroz, no entanto a versão atual do SimulArroz (versão 1.0) não contém a opção de simulção para arroz híbrido. Assim, o objetivo nesta dissertação foi calibrar e avaliar o desempenho do modelo SimulArroz em simular o número de folhas, fenologia, o acúmulo de matéria seca e a produtividade de três cultivares de arroz híbrido no Rio Grande do Sul. Foram conduzidos experimentos de campo em Santa Maria, e nas estações regionais de pesquisa do Instituto Rio Grandense do Arroz de Cachoeirinha, Uruguaiana, Santa Vitória do Palmar, Cachoeira do Sul, Bagé e Camaquã. Foram determinados o número de folhas do colmo principal através da escala da Haun e a fenologia conforme a escala de Counce, e também, foram realizadas amostragens de plantas em Santa Maria e Cachoeirinha para determinar a matéria seca total da parte aérea, de folhas, de colmos, de folhas senescentes e produtividade de grãos. O modelo SimulArroz está calibrado e avaliado para simular o número de folhas no colmo principal, representado pelo Estádio de Haun, a fenologia, a matéria seca total da parte aérea, de folhas, de colmos, de folhas senescentes e a produtividade de grãos a 13% de umidade de três híbridos de arroz irrigado no Rio Grande do Sul.

Cassava (Manihot esculenta Grantz) is one of the most important foods for man and for animals, especially in poor and emergent countries. Maize (Zea mays L.) is the third cereal more produced worldwide. These two crops are often grown in small farms of Rio Grande do Sul. The objectives this study were to estimate the phyllochron and to identify a morphological indicator based on the accumulated number of leaves (NF) on the main stem for the beginning of starch accumulation (IAA) in de fibrous roots of cassava grown in several planting dates, and to quantify growth, development and yield of cassava and maize in different plant spacing in monocropping and intercropping, considering two sowing dates of maize. Two field experiments were carried out in Santa Maria, RS, Brazil during 2005/2006. One experimental was with cassava variety RS 13, with four planting dates (28/09/2005; 11/10/2005; 16/11/2005 and 27/12/2005) and planted in 12 l pots, buried in the soil and spaced 0.8 m. Daily degree days (STd, °C day) were calculated starting at emergency. IAA was determined on the plants when one root reached a diameter of 0.01 m. NF on the date of IAA and the main sterm final leaf number (NFF) up to the first sympodial braches were determined. The phyllochron varied from 20.3 to 29.5 °C day leaf-1 with larger values in the two later planting dates. The NFF varied among the planting dates, increasing as planting was delayed. The NF at IAA was similar for the four planting dates and occurred when NF = 20,9 (±1,0)leaves. The other experiment was carried using the cassava variety RS 13 that was planted on 27/09/2005 and the maize variety BRS Missões sown on two dates: when 50% of the cassava plants were emerged and when the cassava presented five visible leaves. Twelve treatments were used characterizing different plants spacing in the monocropping and intercropping. Several growth, development and yield parameters of both crops were analyzed. Thermal time (Tb=14°C for cassava and Tb=10°C for maize) of some developmental phases and the phyllochron were calculated. Growth and development were not affected by plant spacing in both monocropping and intercropping. The greatest land use efficiency was obtained with intercropping cassava and maize, with cassava planted in a double row spacing of 1.6 x 0.5 x 0.6 m and a single row of maize spaced 0.8 x 0.21 m or two rows of maize spaced 0.4 x 0.42 m between the double row of cassava and maize sowed at cassava emergence. / A mandioca é um dos mais importantes alimentos para o homem e para os animais, especialmente em países pobres e emergentes. O milho (Zea mays L.) é o 3º cereal mais produzido no mundo. Na pequena propriedade familiar do Rio Grande do Sul, é freqüente o cultivo de mandioca e milho. Os objetivos dessa dissertação foram estimar o filocrono e identificar um indicador morfológico baseado no número de folhas acumuladas (NF) na haste principal para o início de acumulação de amido (IAA) em mandioca cultivada em diferentes épocas e quantificar o crescimento, o desenvolvimento e o rendimento da mandioca e do milho em diferentes arranjos de plantas em cultivo solteiro e consorciado considerando-se duas épocas de semeadura do milho. Dois experimentos foram conduzidos na área experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria, RS, em 2005/2006. Um experimento utilizou a mandioca variedade RS 13 em quatro épocas de plantio (28/09/2005; 11/10/2005; 16/11/2005 e 27/12/2005), plantados em baldes de 12 litros, enterrados no espaçamento com 2,0 x 0,8 m. A soma térmica diária (STd, °C dia) foi calculada a partir da emergência. O IAA foi determinado nas plantas quando uma raiz atingia um diâmetro de 0,01 m. O NF na data do IAA e o número final de folhas (NFF) até o primeiro simpódio também foram determinados. O filocrono variou de 20,3 a 29,5 oC dia folha-1 e seus valores foram maiores quanto mais tardio foi o plantio. O NFF variou entre as épocas de plantio, aumentando com o atraso do plantio. O NF no IAA foi similar nas quatro épocas de plantio e ocorreu quando em média o NF= 20,9 (±1,0) folhas. Outro experimento foi conduzido com as culturas de mandioca variedade RS 13 que foi plantada em 27/09/2005 e o milho variedade BRS Missões que foi semeado em duas épocas: quando 50% das plantas de mandioca estavam emergidas e quando a mandioca apresentava cinco folhas visíveis. Doze tratamentos foram usados caracterizando diferentes arranjos de plantas nas culturas solteiras e consorciados. Várias variáveis de crescimento, desenvolvimento e componentes do rendimento das duas culturas foram analisadas. Foi calculada a soma térmica (Tb=14°C para mandioca e Tb=10°C para milho) de algumas fases e determinado o filocrono. O crescimento e o desenvolvimento das duas culturas não foram afetados pelo arranjo de plantas, tanto em cultivo solteiro como em consórcio. O maior uso eficiente da terra (UET) foi obtido no consórcio em que a mandioca foi cultivada em fileiras duplas de 1,6 x 0,5 x 0,6 m e milho em uma fileira de 0,8 x 0,21 m ou em duas fileiras de 0,4 x 0,42 m entre as fileiras duplas de mandioca, sendo o milho semeado na emergência da mandioca.

The Canterbury plains are frequently exposed to summer drought and climate predictions forecast that the severity and frequency of summer drought will increase. The most commonly used pasture grass, perennial ryegrass (Lolium perenne L.), is drought sensitive. One possible method to maintain sward dry matter (DM) production under water stress is to use an alternative grass species such as tall fescue (Festuca arundinacea Schreb.). The objective of this research was to compare summer DM production of monoculture swards of perennial ryegrass and tall fescue under various seasonal drought regimes to study physiological and biochemical drought responses of each species. Data were collected over a period of two-summer seasons, Season One (2006-2007) and Season Two (2007-2008) in an automated rain shelter at Lincoln, Canterbury. Drought treatments included exposure of plants to a spring or autumn drought or a four-weekly "irrigated" drought regime. DM yields of the two species were similar under each watering regime. The control treatment, under non-limiting conditions, has the highest accumulated yield in both Season One and Two for ryegrass (17.1 and 15.7 t DM ha⁻¹) and tall fescue (18.8 and 16.0 t DM ⁻¹) respectively. Spring and autumn drought treatments were similar for the two species in accumulated yield in either season, however the exposure to drought stress returned yields lower than the control. Consistently, the lowest-yielding treatment was the four-weekly irrigated drought, which resulted in an average yield across species in Season One of 10.1 t DM ha⁻¹ and 8.35 t DM ha⁻¹ in Season Two. Growth rates of the swards were calculated using accumulated DM production against accumulated thermal time using a base temperature of 3°C for both species. The control treatments showed a strong linear relationship for both species in both seasons, though Season Two showed a period of approximately 390 °Cd of no growth. Spring growth was similar for all treatments until October when both the spring drought and four-weekly irrigated treatment deviated from the control as water stress commenced. Growth also ceased under autumn drought later in the season. The physiological drought responses between species and among treatments differed. Tall fescue under control conditions had the highest photosynthesis rates of 20.5 µmol CO₂ m⁻² s⁻¹,or 22% higher than ryegrass, whereas the four-weekly irrigated treatment showed no inter-species differences. Differences were also found for other gas exchange parameters. Physiological water use efficiency (phys WUE) in ryegrass was 15% greater than tall fescue in Season Two. Photosynthesis and gas exchange rates against leaf water potential showed declining gas flow in both species across all treatments in response to drying soil conditions and across all irrigation treatments. The osmo-protectant proline was 22% higher in concentration in ryegrass than in tall fescue in Season Two and increased in drought stressed treatments in both seasons. Water stress was found to reduce total chlorophyll concentrations in all treatments and in tall fescue, while little change occurred in the chlorophyll a:b ratio. In conclusion, the findings from this thesis suggest similar DM responses for the two species under drought. The findings suggests that tall fescue performs more as a "water user" under drought conditions, compared with perennial ryegrass, which is more a "water saver." Resonses to the changing environment to a point, before "shuttting up shop" through lower stomatal conductance.

Human body temperature is an important indicator of physical performance and condition in terms of comfort, heat or cold stress. The aim of this research was to develop Temperature Sensing Fabric (TSF) for continuous temperature measurement in healthcare applications. The study covers the development and manufacture of TSF by embedding fine metallic wire into the structure of textile material using a commercial computerised knitting machine. The operational principle of TSF is based on the inherent propensity of a metal wire to respond to changes in temperature with variation in its electrical resistance. Over 60 TSF samples were developed with combinations of different sensing elements, two inlay densities and highly textured polyester yarn as the base material. TSF samples were created using either bare or insulated wires with a range of diameters from 50 to 150 μm and metal wires of nickel, copper, tungsten, and nickel coated copper. In order to investigate the Temperature-Resistance (T-R) relationship of TSF samples for calibration purposes, a customised test rig was developed and monitoring software was created in the LabVIEW environment, to record the temperature and resistance signals simultaneously. TSF samples were tested in various thermal environments, under laboratory conditions and in practical wear trials, to analyse the relationship between the temperature and resistance of the sensing fabric and to develop base line specifications such as sensitivity, resistance ratio, precision, nominal resistance, and response time; the influence of external parameters such as humidity and strain were also monitored. The regression uncertainty was found to be less than in ±0.1°C; the repeatability uncertainty was found to be less than ±0.5°C; the manufacturing uncertainty in terms of nominal resistance was found to be ± 2% from its mean. The experimental T-R relationship of TSF was validated by modelling in the thermo-electrical domain in both steady and transient states. A maximum error of 0.2°C was found between the experimental and modelled T-R relationships. TSF samples made with bare wire sensing elements showed slight variations in their resistance during strain tests, however, samples made with insulated sensing elements did not demonstrate any detectable strain-dependent-resistance error. The overall thermal response of TSF was found to be affected by basal fabric thickness and mass; the effect of RH was not found to be significant. TSF samples with higher-resistance sensing elements performed better than lower-resistance types. Furthermore, TSF samples made using insulated wire were more straightforward to manufacture because of their increased tensile strength and exhibited better sensing performance than samples made with bare wire. In all the human body wear trials, under steady-state and dynamic conditions both sensors followed the same trends and exhibited similar movement artifacts. When layers of clothing were worn over the sensors, the difference between the response of the TSF and a high-precision reference temperature were reduced by the improved isothermal conditions near the measurement site.

Hydropower is the most important power balancing resource in the Swedish electrical power system, regulating the power supply to match the load. Consequently, several hydropower plants have periods of stand-by operation where the power production is absent but where several devices within a plant are still active. Such a device is the step-up power transformer, which during stand-by operation still generates no-load energy losses. These losses can accumulate to a considerable amount of energy and costs during the long technical lifetime of the apparatus. One option to minimize these no-load energy losses is by turning the transformer off when its generating unit is in stand-by operation. However, when this transformer operational change has been explained to experts in the field, the most common response has been that a more frequent reenergizing of a transformer leads to higher risks for errors or transformer breakdowns. This study aimed to analytically investigate three effects from this operational change. First, the potential of fatigue failure for the windings due to the increased sequences of inrush current. Secondly, the thermal cycling as a consequence of change in present losses. Lastly, the energy and economic saving potentials for hydropower plants where this operational adjustment is applied. The study used both established as well as analytical tools explicitly created for this study. These were then applied on currently active transformers in different plant categories in Fortum’s hydropower fleet. The study primarily showed three things. Firstly, risk of fatigue failure due to the increased presence of inrush currents did not affect the transformer’s technical lifetime. Secondly, the thermal cycling changes were slightly larger with absent no-load losses during stand-by operation. The average temperature for the transformer decreased, which in general is seen as a positive indicator for a longer insulation lifetime and thus the transformer’s technical lifetime. Finally, the created frameworks showed the potential of saving energy and money for all plant categories, where the potential grew with the installed production capacity and the stand-by operation timeshare. Despite the simplifications made to describe the complex reality of a transformer operating in a hydropower plant, this thesis contributes to lay a foundation for future investigation of an easy adjustment to avoid unnecessary energy losses and costs for transformers in hydropower plants