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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ion-Selective Optical Sensors for the Management of Plant Nutrient Solutions

Bamsey, Matthew 25 January 2012 (has links)
Traditionally, the condition of hydroponic nutrient solutions used in controlled environment or greenhouse plant production is obtained by monitoring solution pH and electrical conductivity. These parameters provide greenhouse operators with an overall sense of the solution quality, but do not provide information on individual components of the fertilizer solution. Considering that plant nutrient uptake requirements vary with crop, growth phase and environment, real-time ion-selective measurements represent a significant technological advance in the management of recirculating nutrient solutions. The capacity for the monitoring and control of individual ions in the nutrient solution is the last remaining environment variable for which reliable feedback control does not exist in controlled environment plant production. This technology development study focussed on optical ion-selective sensors, termed ‘optrodes’, for potassium and calcium sensing within nutrient solution. Bulk optrode absorption-based sensors, tailored explicitly for nutrient ion activities within typical hydroponic solutions were theoretically modelled, fabricated and experimentally tested. Experimental data on sensor response time, measuring range, selectivity, repeatability, lifetime and influence of temperature were compiled. These ion-selective bulk optrode membranes were integrated into a custom instrument combining a light source, mini-spectrometer, optical fibres and other associated components. Monitoring and control software was written that collected and converted optical measurements into estimated nutrient ion activities for use in managing nutrient solution quality. Implemented spectral averaging, normalization and ratiometric computations and techniques resulted in sensors that offered the advantage of auto-calibration. The sensors met selectivity requirements in half strength Hoagland nutrient solution and provided repeatable measurements in solutions of different ion activity levels. Potassium and calcium selective membranes demonstrated lifetimes of 30 to 50 hours when constantly immersed in nutrient solution. Strategies for their operational implementation in plant growth systems based upon experimental testing are proposed as are suggestions for future study. The low mass, low volume, low cost and robust nature of these optrodes offer a promising technology for future space-based plant production systems and give them excellent terrestrial technology transfer potential.
2

Demi-gods or superchimps? : philosophical examination of the concept of human beings as demi-gods or superchimps

Davis-Armitage, Felicity Patricia January 2008 (has links)
Chance events began with the Big Bang and influenced all subsequent evolutionary processes, including the genesis and evolution of biological life. The complex and versatile human brain has come to dominate the environment. Self-awareness generated the idea of spiritual identity and survival beyond death. The assumption of demi-god status gave sanctity and dignity to humans, a moral separation that justified the exploitation of other animals. But evolution has a common origin, fleshed out in the biological similarities of all mammals, including humans. Neurological and biochemical correlates suggest the omnipresence of consciousness and self-consciousness at levels that vary according to nervous system complexity. Accepting a more inclusive morality does not diminish the value of human life. It acknowledges their power to adapt to changing conditions. Human survival depends on change and human lives can only benefit from a more inclusive worldview that considers the welfare of all sentient beings and the sustainability of a shared environment. / Philosophy and Systematic Theology / M.A. (Philosophy)
3

Demi-gods or superchimps? : philosophical examination of the concept of human beings as demi-gods or superchimps

Davis-Armitage, Felicity Patricia January 2008 (has links)
Chance events began with the Big Bang and influenced all subsequent evolutionary processes, including the genesis and evolution of biological life. The complex and versatile human brain has come to dominate the environment. Self-awareness generated the idea of spiritual identity and survival beyond death. The assumption of demi-god status gave sanctity and dignity to humans, a moral separation that justified the exploitation of other animals. But evolution has a common origin, fleshed out in the biological similarities of all mammals, including humans. Neurological and biochemical correlates suggest the omnipresence of consciousness and self-consciousness at levels that vary according to nervous system complexity. Accepting a more inclusive morality does not diminish the value of human life. It acknowledges their power to adapt to changing conditions. Human survival depends on change and human lives can only benefit from a more inclusive worldview that considers the welfare of all sentient beings and the sustainability of a shared environment. / Philosophy and Systematic Theology / M.A. (Philosophy)
4

Cochonilhas-farinhentas associadas à videira na Serra Gaúcha, bioecologia e controle de Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae). / MEALYBUGS ASSOCIATED IN THE SERRA GAUCHA VINEYARDS, BIOECOLOGY AND CONTROL Planococcus citri (RISSO, 1813) (HEMIPTERA: PSEUDOCOCCIDAE).

Morandi Filho, Wilson José 24 April 2008 (has links)
Made available in DSpace on 2014-08-20T14:07:35Z (GMT). No. of bitstreams: 1 Tese_Wilson_Morandi_Filho.pdf: 463965 bytes, checksum: 4f011d565e10b13a07b93ccabfb80913 (MD5) Previous issue date: 2008-04-24 / Mealybugs of the Pseudococcidae family have been reported as causing direct damage (losses in production) and indirect (transmission of virus) in vineyards. Few information is available about the species occuring in the vineyards and the bioecology of pseudococidae in Brazil. In this work we identified the species of Pseudococcidae associated with vineyards in Serra Gaúcha region; studied the biology and determined the thermal requirements of Planococcus citri estimating the number of annual generations in different producing regions and, evaluated the effect of insecticides alternative to phosphorous for the control of the species. P. citri, Planococcus minor, Pseudococcus viburni, Pseudococcus maritimus, Dysmicoccus brevipes were found associated with the vineyards in the region. P. citri was the most abundant species. The biology of P. citri was studied in leaves of the vine cultivars Cabernet Sauvignon, Italy and Isabel, in fruits of cultivar Italy, in roots of cultivars Isabel and in 101-14 and IAC-572 rootstocks. On roots of the rootstock IAC-572, P. citri was unable to complete the life cycle. The average period from egg to adult males was 24.63 ± 0.10 days with viability of 32% while females lasted 32.00 ± 0.11 days with viability of 56% when fed on leaves of vine cultivars. In roots, the cycle duration of the females and males was 32.45±0.19 and 29.50±0.51 days, respectively. The lowest viability of the nymphal cycle was found in roots of Isabel, 8.1% for females and 4.0% for males while the high viability was obtained in leaves of Cabernet Sauvignon, 62.7% and 32.7% for females and males, respectively. The mealybug P. citri completed the life cycle in leaves of the vine cultivars Cabernet Sauvignon, Italy, Isabel; roots of the rootstocks 101-14 and Isabel. The Italy grape berries allowed the nymphal development of P. citri, however the adults were infertile. The roots of the door graft IAC-572 are immune to P. citri. The speed of development of P. citri increases with temperature elevation. The temperatures of 25°C and 28°C were the most appropriate for the insect development. The threshold temperature and thermal constant for the full cycle (egg-adult) of P. citri in vine leaves of the cultivar Italy was 8.16°C and 574.71 degree days, respectively. Based on the thermal requirements, we estimated that the insect may have 5.7 annual generations in Bento Gonçalves (RS), 6.2 in Bagé (RS), 6.9 in São Lourenço (MG), 7.9 in Londrina ( PR), 9.7 in Jales (SP) and 11.5 in Petrolina (PE). In the assessment of insecticides for the control of the insect, the neonicotinoids acetamiprid (0.60 g ai / plant), imidacloprid (0.70 g ai / plant) and thiamethoxam (0.75 g ai plant) were effective in the control of P. citri in vine plants with 1 year old. In adult plants (15 years) the same treatments and doses were not effective to pest control. Foliar spray of acetamiprid (6 20 ia/100L), imidacloprid (7 ia/100L), thiamethoxam (7.5 g ia/100L) and insect growth regulators buprofezin (25 ia/100L) and pyriproxyfen (10g ai 100L) were not effective to control P. citri. / Cochonilhas da família Pseudococcidae têm sido relatadas como causadoras de danos diretos (perdas na produção) e indiretos (transmissão de vírus) na cultura da videira. Poucas informações estão disponíveis sobre as espécies presentes nos vinhedos e a bioecologia das mesmas. Neste trabalho foram identificadas as espécies de Pseudococcidae associados à cultura da videira na região da Serra Gaúcha; estudado a biologia e determinado as exigências térmicas de Planococcus citri, estimado o número de gerações anuais nas diferentes regiões produtoras e avaliado o efeito de inseticidas alternativos aos fosforados para o controle da espécie. P. citri, Planococcus minor, Pseudococcus viburni, Pseudococcus maritimus, Dysmicoccus brevipes foram constatadas associadas à cultura da videira na região da Serra Gaúcha, sendo que P. citri foi a espécie mais abundante nos vinhedos. A biologia de P. citri foi estudada em folhas de videira das cultivares Cabernet Sauvignon, Itália e Isabel, bagas da cultivar Itália e raízes da cultivar Isabel e porta-enxertos 101-14 e IAC-572. Em raízes do porta-enxerto IAC-572 a cochonilha não completou o ciclo biológico. Em bagas de uva Itália, o inseto completou a fase de ninfa, porém os adultos foram inférteis. Em folhas de videira das diferentes cultivares, a duração média do período ovo a adulto dos machos foi de 24,630,10 dias com viabilidade de 32% enquanto que as fêmeas duraram 32,000,11 dias com viabilidade de 56%. Em raízes, a duração do ciclo biológico das fêmeas e machos foi de 32,450,19 e 29,500,51 dias, respectivamente. A menor viabilidade do ciclo ninfal foi verificada em raízes de Isabel, sendo de 8,1% para fêmeas e 4,0% para machos enquanto a maior foi obtida em folhas de Cabernet Sauvignon, sendo de 62,70% e 32,7% para fêmeas e machos, respectivamente. Em folhas a fecundidade foi de 67,2710,70; 53,331,68 e 66,094,68 ovos por fêmea nas cultivares Cabernet Sauvignon, Itália e Isabel, respectivamente. Enquanto em raízes, foi obtido 30,406,12 e 70,0010,5 ovos por fêmea no porta-enxerto 101-14 e Isabel, respectivamente. A velocidade de desenvolvimento de P. citri aumenta com a elevação da temperatura sendo a faixa de temperatura entre 25 ºC e 28 ºC a mais adequada para a espécie. A temperatura base e a constante térmica para o ciclo total (ovo-adulto) de P. citri em folhas de videira da cultivar Itália foi de 8,16 ºC e 574,71 graus-dia, respectivamente. Com base nas exigências térmicas estimou-se que o inseto pode completar 5,7 gerações anuais em Bento Gonçalves (RS), 6,2 em Bagé (RS), 6,9 em São Lourenço (MG), 7,9 em Londrina (PR), 9,7 em Jales (SP) e 11,5 em Petrolina (PE). Na avaliação de inseticidas para o controle de P. citri verificou-se que os neonicotinóides acetamiprid (0,60g i.a./planta), imidacloprid (0,70g i.a./planta) e tiametoxam (0,75g i.a./planta) são eficazes no controle de P. citri em plantas de videira com um ano de idade. Entretanto, em plantas com 15 anos de idade de C. sauvignon os inseticidas neonicotinóides acetamiprid, imidacloprid e tiametoxam nas mesmas doses não foram eficazes para o controle da espécie. Ao estudar o efeito dos inseticidas neonicotinóides acetamiprid (6g i.a./100L), imidacloprid (7g i.a./100L), tiametoxam (7,5g i.a./100L) e os reguladores de crescimento buprofezin (25g i.a./100L) e pyriproxyfen (10g i.a./100L) aplicados via foliar observou-se que os mesmos não proporcionam mortalidade significativa de P. citri na cultura da videira após a pulverização nos vinhedos e avaliação da mortalidade em laboratório.

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