The temporal system of fruiting on the cotton plant lends itself to bolls at different fruiting sites developing under different environmental conditions and with varied source-sink relationships. To investigate this, intra-plant fiber quality was assessed in four upland cultivars at College Station, Texas for three years and at Lubbock, Texas for two years. It was concluded that fiber quality steadily declines from the bottom sympodial branches towards the upper branches. 'FiberMax 832' had the best fiber quality among all cultivars but it also had the highest degree of variability within the plants. 'Half and Half' and 'Acala 1517-99' appear to have the least amount of intra-plant variability of fiber quality. Bolls from the bottom region of the plant have higher trash content compared to the upper region. To test the impact of fiber quality variability on boll sampling techniques employed, ten sampling protocols were compared against each other for three years in College Station, Texas, for two upland cultivars. Results suggest that randomized boll samples containing 50 bolls worked well to estimate inherent fiber quality for most fiber traits while estimation of trash and lint percent was not predictable based on boll samples. One of the problems associated with intra-plant fiber variability was the presence of immature fibers. In order to determine the potential for improvement of fiber maturity and standard fineness, five upland cotton (Gossypium hirsutum L.) genotypes were subjected to a diallel analysis at College Station, Texas, in 2011. Four cultivars that tend to produce fine and mature fibers and one cultivar that tends to produce coarse fibers were intermated in all combinations, without reciprocals. Estimates of general (GCA) and specific combining ability (SCA) for fiber maturity ratio and standard fineness based on Griffing's diallel Model I, Method 4 were calculated for AFIS and fiber micronaire, length and strength measurements for High Volume Instrument (HVI). Four parents had significant GCA effects and Acala 1517-99 was found to be the best parent for improving standard fineness followed by FiberMax 832 and 'Tamcot HQ-95'. Tamcot HQ-95 was the best parent to improve fiber maturity ratio while 'Deltapine 90' was the best parent to reduce fiber maturity ratio. The specific cross between Acala 1517-99 and Tamcot HQ-95 had the best performance. Diallel analysis indicated that fiber maturity ratio was influenced by non-additive gene effects more than additive gene effects while fiber standard fineness was highly influenced by additive gene effects. Developing cultivars with optimal fiber standard fineness and maturity should be prioritized to address problems associated with neps and short fiber content and improve spinning performance of US cotton.

O problema de modos intra-planta em sistemas de potência é caracterizado pela oscilação dos geradores de uma mesma usina uns contra os outros. Estes modos são geralmente bem amortecidos, mas uma sintonia inadequada dos parâmetros dos PSSs (Power System Stabilizers), visando fornecer um amortecimento aos modos locais, por exemplo, pode reduzir o amortecimento dos modos intra-planta. Esta possibilidade pode ser evitada por uma sintonia cuidadosa dos estabilizadores, em um modelo que seja capaz de representar os modos intra-planta. Este processo de sintonia pode ser tedioso e demorado, exigindo muitas horas de trabalho de um especialista. Neste trabalho, apresentamos um algoritmo computacional capaz de realizar esse processo, com uma intervenção mínima do projetista (reduzindo, portanto, o esforço do engenheiro projetista na sintonia do PSS e deixando que o computador faça de maneira eficiente) e aplicamos este algoritmo para encontrar uma sintonia adequada de PSSs para o amortecimento dos modos local e intra-planta coexistentes no mesmo sistema. Como mostrado neste trabalho, o algoritmo é capaz de sintonizar os PSSs para varias condições de operação de uma só vez, o que pode também resultar em uma melhor sintonia quando comparado com abordagens seqüenciais de projeto. / The problem of intra-plant modes is characterized by the oscillation of the machines within a power station against each other. These modes are usually well-damped, but improper settings for the parameters for power system stabilizers (PSSs), aiming at enhancing the damping of local modes, for example, can reduce the damping of the intra-plant modes. This possibility must be avoided by a careful tuning of the stabilizers, over a model that is able to represent the intra-plant modes. This tuning process may be involved and time-consuming, requiring many hours of work from a specialist. In this paper, we present a computerized algorithm that is capable of performing this process with minimum intervention of the human designer (therefore alleviating the burden of PSS tuning for the engineer and placing most of it on the computer) and apply it to find a PSS tuning to damp both local and intra-plant modes of the same plant. As shown in the paper, the algorithm is capable of tuning PSSs for several operating conditions at once, which may also result in better tuning when compared to sequential approaches.

O problema de modos intra-planta em sistemas de potência é caracterizado pela oscilação dos geradores de uma mesma usina uns contra os outros. Estes modos são geralmente bem amortecidos, mas uma sintonia inadequada dos parâmetros dos PSSs (Power System Stabilizers), visando fornecer um amortecimento aos modos locais, por exemplo, pode reduzir o amortecimento dos modos intra-planta. Esta possibilidade pode ser evitada por uma sintonia cuidadosa dos estabilizadores, em um modelo que seja capaz de representar os modos intra-planta. Este processo de sintonia pode ser tedioso e demorado, exigindo muitas horas de trabalho de um especialista. Neste trabalho, apresentamos um algoritmo computacional capaz de realizar esse processo, com uma intervenção mínima do projetista (reduzindo, portanto, o esforço do engenheiro projetista na sintonia do PSS e deixando que o computador faça de maneira eficiente) e aplicamos este algoritmo para encontrar uma sintonia adequada de PSSs para o amortecimento dos modos local e intra-planta coexistentes no mesmo sistema. Como mostrado neste trabalho, o algoritmo é capaz de sintonizar os PSSs para varias condições de operação de uma só vez, o que pode também resultar em uma melhor sintonia quando comparado com abordagens seqüenciais de projeto. / The problem of intra-plant modes is characterized by the oscillation of the machines within a power station against each other. These modes are usually well-damped, but improper settings for the parameters for power system stabilizers (PSSs), aiming at enhancing the damping of local modes, for example, can reduce the damping of the intra-plant modes. This possibility must be avoided by a careful tuning of the stabilizers, over a model that is able to represent the intra-plant modes. This tuning process may be involved and time-consuming, requiring many hours of work from a specialist. In this paper, we present a computerized algorithm that is capable of performing this process with minimum intervention of the human designer (therefore alleviating the burden of PSS tuning for the engineer and placing most of it on the computer) and apply it to find a PSS tuning to damp both local and intra-plant modes of the same plant. As shown in the paper, the algorithm is capable of tuning PSSs for several operating conditions at once, which may also result in better tuning when compared to sequential approaches.

No description available.