Spelling suggestions: "subject:"poo"" "subject:"ppop""
141 |
Influência da idade do fruto no período de incubação e na expressão de diferentes tipos de sintomas da mancha preta dos citros / Influence of fruit age on the incubation period and in the expression of different types of symptoms of citrus black spotGuilherme Fernando Frare 08 October 2015 (has links)
A mancha preta dos citros (MPC), causada por Phyllosticta citricarpa, é uma doença de importância econômica devido à redução na produtividade ocasionada pela queda prematura dos frutos e ao aumento dos custos da produção devido ao uso intensivo de fungicidas. As lesões restringem-se praticamente ao flavedo dos frutos, depreciando-os para a comercialização e restringindo a exportação de frutas in natura. A MPC causa danos em todas as espécies cítricas de valor comercial, com exceção da Citrus aurantium (laranja azeda) e do Citrus latifólia (lima ácida Tahiti). Phyllosticta citricarpa causa infecções latentes e diferentes tipos de sintomas nos frutos. Essas características podem estar relacionadas com o estádio fenológico do fruto no momento da infecção. Os objetivos desse trabalho foram avaliar a influência da idade dos frutos de laranja doce na germinação dos conídios e no período de incubação de P. citricarpa e identificar compostos fenólicos pré ou pós-formados no flavedo de frutos de laranja doce inoculados com P. citricarpa. Frutos de laranjeira das variedades Hamlin, Valência e Pêra com 1,5, 3,0, 5,0 e 7,0 cm de diâmetros foram inoculados com suspensão de conídios de P. citricarpa na concentração de 103 e 105 conídios.mL-1 e avaliados mensalmente. O primeiro sintoma observado foi o da falsa melanose e não foram observadas diferenças no período de incubação entre as variedades. O período de incubação da falsa melanose foi afetado pela concentração de inóculo e pelo diâmetro dos frutos. Frutos de 1,5 e 3,0 cm de diâmetro inoculados com suspensão de conídios de P. citricarpa, na concentração de 103 conídios.mL-1, apresentaram sintomas entre 70 e 116 dias respectivamente, enquanto que os frutos de 1,5, 3,0 e 5,0 cm de diâmetro, inoculados com suspensão de 105 conídios.mL-1, expressaram sintomas entre 40, 65 e 156 dias respectivamente. A expressão dos sintomas de mancha dura não diferiu entre as concentrações de inóculo, mas diferiu entre os diâmetros e entre as variedades avaliadas. A variedade Valência apresentou os menores tempos para o aparecimento dos sintomas quando comparado com as variedades Hamlin e Pêra. Os tempos médios para a expressão da mancha dura nos frutos (todas as variedades) inoculados com 1,5, 3,0, 5,0 e 7,0 cm de diâmetro foram 240, 217, 176 e 197 dias respectivamente. Sintomas de falsa melanose e mancha dura se expressaram independente um do outro. Não foi observado diferenças nas quantidades dos compostos fenólicos entre os frutos inoculados e não inoculados após 48 h de câmara úmida. As maiores quantidades de compostos fenólicos foram encontradas nos frutos menores e à medida que estes aumentaram de tamanho, observou-se a diminuição nas quantidades destes compostos. Não foram observadas diferenças no padrão de germinação do fungo em relação aos diferentes diâmetros inoculados, porém foram observadas placas de cera na superfície dos frutos de 7,0 cm de diâmetro. Os sintomas de falsa melanose parecem estar relacionados com a defesa da planta, e os sintomas de mancha dura estão relacionados com o estádio fenológico dos frutos. / Citrus black spot (CBS), caused by Phyllosticta citricarpa, is a disease of economic importance due to the reduction in yield, caused by premature fruit drop, and high production costs, due to the intensive fungicide spraying. The lesions are restricted to the fruit flavedo, decreasing market prices and restricting exports of fresh fruits. CBS causes damage in all commercial citrus species with exception of Citrus aurantium (sour orange) and Citrus latifolia (Tahiti acid lime). Phyllosticta citricarpa causes latent infections and different types of symptoms on fruit. These characteristics may be related to the phenological stage of the fruit at the time of infection. The objectives of this study were to evaluate the influence of fruit age of sweet orange on conidia germination and on the incubation period of P. citricarpa and identify phenolics pre or post-formed in the flavedo of sweet orange inoculated with P. citricarpa. Orange fruits of varieties Hamlin, Valencia and Pera with 1.5, 3.0, 5.0 and 7.0 cm of diameters were inoculated with a conidia suspension of P. citricarpa at the concentration of 103 and 105 conidia.mL-1 and were evaluated monthly. The first symptom observed was false melanose and no differences were found in the incubation period among the varieties. The incubation period of false melanose was affected by the inoculum concentration and fruit diameters. Fruits with 1.5 and 3.0 cm of diameter inoculated with a conidia suspension of P. citricarpa, at a concentration of 103 conidia.mL-1, showed symptoms between 70 and 116 days, respectively. On the other hand, fruits with 1.5, 3.0 and 5.0 cm in diameter, inoculated with suspension of 105 conidia.mL-1, expressed symptoms between 40, 65 and 156 days, respectively. The period for symptom expression of hard spot did not differ between inoculum concentrations. The incubation period differed between the diameters and varieties evaluated. The Valencia variety presented symptoms in a shorter time than Hamlin and Pera. The average times for hard spot expression in fruits (all varieties together) inoculated with 1.5, 3.0, 5.0 and 7.0 cm of diameter were 240, 217, 176 and 197 days, respectively. Symptoms of false melanose and hard spot were expressed independently from each other. No differences were observed in the amounts of phenolic compounds between inoculated and non-inoculated fruits after 48 h of incubation in a humid chamber. The highest amounts of phenolic compounds were found in smaller fruits and, as fruits increased size, there was a decrease in the amounts of these compounds. No differences were found in the germination pattern of fungus on the inoculated fruits, but wax plates were observed on the surface of fruits with 7.0 cm in diameter. Symptoms of false melanose seem to be related to the plant defense mechanism, and symptoms of hard spot appeared to be related with phenological stages of the fruits.
|
142 |
Spot test quantitativo para chumbo com análise de imagens, aplicado a solos / Spot test for lead in soilsCastro, Patrícia de Pádua, 1980- 23 August 2018 (has links)
Orientador: Adriana Vitorino Rossi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-23T10:19:07Z (GMT). No. of bitstreams: 1
Castro_PatriciadePadua_D.pdf: 5260822 bytes, checksum: f6893f2bb59ad505050a8c1a755fee4a (MD5)
Previous issue date: 2013 / Resumo: Pb(II) e um contaminante acumulativo em solos; reações de spot test servem para análises exploratórias para avaliar contaminações. A reação de spot test entre Pb(II) e rodizonato (ROD) forma um complexo vermelho (PbROD), que pode ser quantificado em dispositivo microfluídico em papel (mPAD) em associação com análise digital de imagens, estudada neste trabalho para aplicação em solos. Misturas reacionais de ROD 9,96 mmol L, em tampão tartarato, e soluções aquosas de Pb(NO3)2 na faixa de concentração de 0,20 a 5,00 mmol L foram utilizadas para a formação de PbROD em mPAD e empregadas no desenvolvimento do método que envolveu a utilização de um scanner comercial para obtenção das imagens e, um programa para extração de dados de cores em sistema RGB (Red, Green e Blue) para quantificação por meio de curvas de calibração. O método desenvolvido foi aplicado para análise de Pb(II) em 28 amostras de solos dopadas com (PbNO3)2 a uma concentração 300 mg kg de solo, utilizando solução de HNO3 0,43 mmol L como extrator, que extraiu em média 75% do Pb(II) adicionado. A limitação imposta pelas barreiras hidrofóbicas no mPAD foi crucial para viabilizar a quantificação de Pb(II). Os dados extraídos da componente G da imagem do produto da reação obtido no mPAD apresentaram os melhores resultados. A precisão intermediária do método de spot test para Pb(II) formando PbROD foi 4 %, com limites de detecção e quantificação iguais a 0,07 e 0,24 mmol L, respectivamente. Das 28 amostras estudadas, sete não desenvolveram cor na reação devido às características físicas e químicas dos solos e a presença de possíveis interferentes (principalmente Ba, Sr, Matéria Orgânica, P e Argila). A grande heterogeneidade dos solos e os complexos mecanismos de adsorção e dessorção dos íons que afetam sua disponibilidade para a reação de análise representam aspectos limitantes para a aplicação do método desenvolvido, porém os resultados apontaram adequação para análise semiquantitativa exploratória de Pb(II) em áreas de solos contaminados / Abstract: Lead (Pb) is a cumulative soil contaminant, which can be assessed by spot test reactions in exploratory analyzes regarding soil contamination. The spot test reaction between Pb(II) and rhodizonate (ROD) forms a red complex (PbROD), which can be quantified on paper microfluidic device (mPAD) in combination with digital image analysis. The objective with this work was to develop a method based on the aforementioned system, for the determination of Pb(II) in soils. Reaction mixtures containing 9.96 mmol L of ROD (prepared in tartrate buffer) and aqueous solutions of Pb(NO3)2 in a concentration range from 0.20 to 5.00 mmol L were used to form PbROD in mPAD and employed for the method development. A commercial scanner was used to obtain images and a program was employed to extract data from the RGB (Red, Green and Blue) colors system for Pb(II) quantification, by using calibration curves. The method was applied for the analysis of Pb(II) in 28 soil samples spiked with Pb(NO3)2 at a concentration of 300 mg kg of soil and a 0.43 mmol L HNO3 solution was used as the extractant, which was able to extract, in average, 75% of Pb(II) added. The limitation imposed by hydrophobic barriers in the mPAD was crucial to enable the quantification of Pb(II). The data extracted from the G component of the image of the reaction product obtained in the mPAD showed the best results. Intermediate precision of the spot test method for Pb(II) forming PbROD was 4%, with limits of detection and quantification equal to 0.07 and 0.24 mmol L, respectively. From the 28 samples studied, seven did not develop color in the reaction, due to their physical and chemical characteristics and the presence of possible interferences (mainly Ba, Sr, Organic matter, P and clay content). The great heterogeneity of soils and the complex mechanisms of sorption and desorption of ions, that affect their availability for reaction analysis, represent limiting aspects for the quantitatively application of the method for soils. But the results show suitability for semiquantitative exploratory analyzes of Pb (II) in areas with soils contaminated with this element / Doutorado / Quimica Analitica / Doutora em Ciências
|
143 |
Pricing of Power Derivatives / Pricing of Power DerivativesFoukal, Viktor January 2014 (has links)
The main target of this thesis is to summarize and demonstrate the main characteristic of power markets and trying to find out electricity spot model. Thesis starts with definition of market subjects, typology of traded contracts and description of market development with focus on South Easter Europe. Thesis continues with development of consumption function and theoretical concepts of Demand/Capacity ratio which is used in short term/spot modeling and serve to identify a risk of potential increase in volatility. After deriving fundamental models I will continue with stochastic model - Volatility Regime model with Jump diffusion. I used all these knowledge and observed patterns in order to evaluate illiquid power options with daily settlement.
|
144 |
Studium kvality řezu mezních tlouštěk oxidačního řezání v závislosti na průměru ohniskového spotu při laserovém dělení materiálu / Study cutting quality of flame cutting of limit thicknesses depending on the diameter of the focal spot during laser cutting of materialMaňas, Petr January 2016 (has links)
Experimental work evaluated the dependence of the thickness of the cutting edge, its roughness and assessment of appearance with regard to the defects resulting from the diameter of the focal spot during oxidative cutting Yb:YAG laser. Other variables include the experiment: process parameters such as laser power, cutting speed, oxygen pressure and focus position. Experiment is based on the Taguchi tables. Test samples were cut off from sheet thickness 10, 15 and 20 mm. Representatives of conventional steel were S235JRC+N, S235JR, S235JR+N and steel type RAEX developed for laser and plasma cutting. Samples were evaluated according to the ČSN EN ISO 9013. The evaluation of samples was into classes according to standards of quality. Hardness measurements were performed on the samples thickness 20 mm of convectional steel and steel type RAEX.
|
145 |
Var begås den allvarligaste brottsligheten i Malmö? En jämförelse mellan särskilt utsatta område och resterande MalmöPersson, David, Hallström, Karl January 2019 (has links)
Brott mot person i offentlig miljö är en av de brottskategorier som skapar störst otrygghet i det svenska samhället. Under 2018 anmäldes totalt 5101 brott mot person i offentlig miljö i Malmö, vilket är cirka 10% av de totalt anmälda brotten i Malmö. För att minska brott i offentlig miljö krävs det att polisen arbetar effektivt och på rätt platser. Tidigare forskning visar på att arbete med ”hot spot” är en effektiv metod inom det polisiära brottspreventiva arbetet och ”harm spot” kan vara ett bra alternativ till att förbättra arbetet ytterligare. I denna uppsats är syftet att ge polisen ytterligare information om var den allvarligaste brottsligheten i Malmö sker. Detta genom att undersöka och presentera ”hot & harm spot”-kartor som jämför brottsligheten i Malmös delområden. Studien ämnar delvis att visa var brotten med högt skadevärde sker och om det verkligen sker i de särskilt utsatta områdena, Lindängen, Seved och Rosengård (NOA 2017), eller om det sker över hela Malmö. Studien ämnar även att undersöka om ”hot spots” och ”harm spots” stämmer överens gällande var brottsligheten i offentlig miljö begås. Resultaten i studien tyder på att brott i offentlig miljö framförallt sker i de centrala delarna i Malmö och att de platser som beräknas ha högst skadevärde finns i Lindängen och i centrum. Det vill säga enbart i ett av tre särskilt utsatta områden. / The public crime is the type of crime that makes people feel most unsafe in the Swedish society. During 2018 there was a total of 5101 criminal notifications of crimes against people in public spaces in the city of Malmö, which is approximately 10% of all reported crimes in Malmö. It is important for the police to work efficiently and with precision to reduce the public crime. ”Hot spot policing”, as an method for the police, is shown to have good results in making their work in reducing crime more efficient and ”harm spot policing” could be an alternative to make their work even more efficient. The main goal of this study is to give the Malmö police more knowledge about where the most serious crime in Malmö occur, by using the ”Swedish Crime Harm Index” made by Rinaldo (2015). The aim is to compare and to present the public crimes in particularly deprived areas and the remaining Malmö by using ”hot-” and ”harm spot” maps. According to the “Nationella operativa avdelningen” (2017) there are three particularly deprived areas in Malmö, which is Lindängen, Seved and Rosengård. The study will also look into if the ”hot spots” and ”harm spots” will differ in the places where the crimes is commited. The result in this study mainly show that the most crimes occur in the central parts of Malmö and the crimes with highest harm value occur in Lindängen and the central areas. Which means in only one out of three of the particularly deprived areas.
|
146 |
Resistance and Ultrasonic Spot Welding of Light-Weight MetalsLu, Ying January 2018 (has links)
No description available.
|
147 |
Evaluation of Ultradwarf Bermudagrass Cultural Management Practices and Identification, Characterization, and Pathogenicity of Ectotrophic Root-Infecting Fungi Associated with Summer Decline of Ultradwarf Bermudagrass Putting GreensVines, Phillip Lavelle 14 August 2015 (has links)
This research addressed the effects of cultural management practices, cultivar selection, and applications of seasonal fungicides on ultradwarf bermudagrass health and playability and occurrence of foliar diseases. Additionally, novel ectotrophic root-infecting fungi were isolated from ultradwarf bermudagrass roots exhibiting symptoms of summer decline, identified via multilocus phylogenetic analyses, and characterized by morphological assessments and pathogenicity evaluations.
|
148 |
Development and Characterization of Friction Bit Joining: A New Solid State Spot Joining Technology Applied to Dissimilar Al/Steel JointsSiemssen, Brandon Raymond 18 June 2008 (has links) (PDF)
Friction bit joining (FBJ) is a new solid-state spot joining technology developed in cooperation between Brigham Young University of Provo Utah, and MegaStir Technologies of West Bountiful Utah. Although capable of joining several different material combinations, this research focuses on the application of FBJ to joining 5754 aluminum to DP 980 steel, two alloys commonly used in automotive applications. The thicknesses of the materials used were 0.070 inches (1.78 mm) and 0.065 inches (1.65 mm), respectively. The FBJ process employs a consumable 4140 steel bit and is carried out on a purpose built research machine. In the first stage of the weld cycle the bit is used to drill through the aluminum top sheet to be joined. After this, spindle speed is increased so that the bit tip effectively forms a friction weld to the steel bottom sheet. Momentary stoppage of the spindle facilitates weld cooling before the spindle is restarted, shearing the bit tip from the bit shank, and retracted. Incorporated into the bit tip geometry is a flange that securely holds the aluminum in place after joint formation is complete. This research consists of several developmental steps since the technology only recently began to be formally studied. Initial joint strengths observed in lapshear tensile testing averaged only 978.5 pounds (4.35 kN), with a relatively high standard deviation for the data set. Final lapshear tensile test results were improved to an average of 1421.8 pounds (6.32 kN), with a significantly lower, and acceptable, standard deviation for the data set. Similar improvements were realized during the development work in cross tension tensile test results, as average strengths increased from 255.8 pounds (1.14 kN) to 566.3 pounds (2.52 kN). Improvements were also observed in the standard deviation values of cross tension data sets from initial evaluation to the final data set presented in this work.
|
149 |
Spot Welding of Advanced High Strength Steels (AHSS)Khan, Mohammad Ibraheem 20 April 2007 (has links)
Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced.
The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone.
Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.
|
150 |
Spot Welding of Advanced High Strength Steels (AHSS)Khan, Mohammad Ibraheem 20 April 2007 (has links)
Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced.
The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone.
Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.
|
Page generated in 0.2551 seconds