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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.
41

Características morfogênicas e estruturais do Panicum maximum Jacq cv. Milênio sob adubação / Morphogenetic and structural traits of Panicum maximum cv Jacq. Milênio under fertilization

Rodrigues, Juliana Ferraz Huback 22 February 2006 (has links)
Made available in DSpace on 2015-03-26T13:54:42Z (GMT). No. of bitstreams: 1 texto completo.pdf: 318170 bytes, checksum: 7094c303aee48b13607620211770c78c (MD5) Previous issue date: 2006-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The experiment was conducted in a greenhouse under natural light and temperature, at the Department of Animal Science, University of Viçosa, Minas Gerais. The growth of P. maximum cv. Milênio (BRA 006,998) was evaluated in plastic pots with holes for drainage of excess water. The treatments consisted of a factorial arrangement 4 x 4 x 4 corresponding to four doses of nitrogen (N), phosphorus (P), and potassium (K) in the completely random design with two replications. The doses of nutrients were: 0, 80,120 and 160 mg.dm-3 of N as urea, 50, 100, 200 and 300 mg.dm-3 of P in the form of triple superphosphate, and 0, 80, 120 and 160 mg dm-3 of K in the form of potassium chloride. The morphogenic and structural traits were evaluated by marking three tillers per pot, measuring three times a week. By these measures were estimated the morphogenic traits: TApF, Filo, TAlF, TAlC, TSF, as well as, the structural traits: RFC, DVF, NFV, CFF and NPerf. The measures were ceased after the total senescence of the first leaf fully expanded in two plants of each experimental unit, making the cutting of plants to estimate the total production of MS per pot, MSF and MSC. After the evaluation, the results were reduced to the average of treatments, and analyzed by factor analysis. Two factor analysis were made for the 23 original variables (traits), aiming to condense the information in a smaller set of factors, with a minimum loss of this information. The first analyze, we considering ten morphogenetic and structural traits, and the second one, we analyzed the other thirteen production traits. The variables were grouped by their correlation and each group of variables was a factor. Response surface methodology was applied using factorial scores estimated to analyze the combinations of N, P and K. The factor analysis reduced the ten morphogenic and structural traits for three factors, with retention of 79.07% of the total variation of data and only 20.91% loss for information of the total variables. The first factor explained 47.61% of the total variance of the data, correlating positively to the variables TApF (0.9114), TAlF (0.8907), TSF (0.8361), TAlC (0.7752) and negatively with variable Filo (-0.8851) and DVF (-0.8031). Because of the high correlation coefficients of these factors, it was conventionally called to the morphogenetic traits of the grass milênio (CM Factor). The second factor explained 17.91% of the total variance of the data, showing a positive correlation with the variables NPerf (0.8954) and CFF (0.62155), and negative correlation with the characteristic RFC (-0.7809) indicating that this factor is associated with the "structural traits" of this forage plant (Factor EC). The third factor, called "Number of Leaves Live" (Factor NFV) of grass milênio, explained 13.54% of the total variance of the data and it was correlated only with a positive characteristic NFV (0.8075). The observed values of the factorial scores of CM showed a polynomial tendency (P<0.01) and the analysis of variance was significant (P<0.01) for N, K, as well as, for the negative interaction between the doses of these two nutrients applied. It was not observed for these variables, significant effect of P. The factorial scores of CM had estimated linear trend to the increasing levels of nitrogen and applied to the linear decreasing doses of K. It was in grass-millennium, positive response of the variables TApF, TAlF, TAIC and TSF (Factor CM) at doses of N. The DVF showed negative correlation with other variables. The factor EC varied significantly (P<0.01) with doses of N and K, and the interaction between the two nutrients was not significant (P>0.01). The equation of polynomial regression showed adjustment to the linear and quadratic effects, according to the rates of N and K, respectively. There was a negative correlation of variable RFC with the CFF and the NPerf variables, which integrated the Factor EC. The factor NFV was influenced significantly (P<0.01) only by nitrogen fertilization, adjusting for the quadratic effect. It was observed from the dose of 80 mg.dm-3 N, linear increase in scores factorial estimated that factor with the supply of N to the highest dose tested of 160 mg.dm-3. For the variables related to the production of grass milênio under fertilization, the factor analysis by the method of principal components, provided the reduction from thirteen variables to three factors, with retention of 95.12% of the total variation of data and only 4.88% loss of information. It was observed that the first factor, called Factor "forage production" (Factor PF) of grass milênio, explained 43.99% of the total variance of the data correlated positively with the variables: MSF (0.9859), MSC (0.9930), MST (0.8493), BP (0.9966), PAMM (0.9913) as demonstrated by their factor loading. The second factor, called factor "Growth forage" (Factor CF) of grass milênio, explained 34.92% of the total variance of the data showed high and positive correlation with the variables Leaf % (0.9502), Colmo % (0, 8827), RPAR (0.9205) and negative correlation with MSR (- 0.74482) and Root % (-0.9669). The third factor, called factor "Grass senescent" (FSen) of grass milênio, it was correlated with a positive MSMM (0.9063) and MM % (0.8809) and a negative impact on variable RPAMM (-0.9095). The observed values of the factorial scores of PF had a polynomial tendency (P<0.01). This analysis showed significance (P<0.01) for the doses of K provided in the solution, giving the factorial scores estimated quadratic trend for this factor for K nutrient. The interactions between the nutrients N and P, and between K and N, and between P and K were significant (P<0.01), giving the factorial scores estimated for the grass milênio PF the linear growing inclination for the three interactions, respectively. The analysis of variance factor for the FA showed no significance (P>0.01) for any of the three nutrients (N, P and K) studied. The observed values of the factorial scores of FSen a polynomial tendency (P<0.01). The analysis of variance showed the same significance (P<0.01) for the doses of N and K. The factorial scores of the estimated factor FSen tended square, with point of maximum for levels of nitrogen, and linear trend for the decreasing levels of K, as well as, the greatest factor scores estimated in the larget dose of N and smaller of K. / O experimento foi conduzido em casa de vegetação no Departamento de Zootecnia, sob luz e temperatura ambiente, no campus da Universidade Federal de Viçosa, Minas Gerais. Avaliou-se o P. maximum cv. Milênio (BRA 006998) cultivado em vasos plásticos com orifícios para drenagem do excesso de água. Os tratamentos foram constituídos de um arranjo fatorial 4x4x4 correspondente a quatro doses de nitrogênio (N), quatro de fósforo (P) e quatro de potássio (K) no delineamento inteiramente ao acaso, com duas repetições. As doses dos nutrientes foram: 0, 80,120 e 160 mg.dm-3 de N, na forma de uréia, 50, 100, 200 e 300 mg.dm-3 de P, na forma de superfosfato triplo, e de 0, 80, 120 e 160 mg dm-3 de K, na forma de cloreto de potássio. Para avaliações das características morfogênicas e estruturais foram marcados três perfilhos por vaso, mensurados três vezes por semana. Através das medidas registradas foram estimadas as características morfogênicas: TApF, FILO, TAlF, TAlC ,TSF e estruturais: RFC, DVF, NFV, CFF e NPerf. Após total senescência da primeira folha completamente expandida, em duas plantas de cada unidade experimental cessaram-se as avaliações, efetuando-se o corte das plantas para estimativa da produção total de MS por vaso, produção de MSF e MSC. Após as avaliações, os resultados foram reduzidos às médias dos tratamentos, sendo analisados pela análise de fatores, adotando-se como critérios de seleção dos fatores, as cargas fatoriais e a comunalidade. Com o objetivo de condensar as informações, contidas nas 23 variáveis originais estudadas, em um conjunto menor de fatores, com um mínimo de perda dessas informações, foram feitas duas análises de fatores. Uma, considerando dez características morfogênicas e estruturais e a segunda análise de fatores, avaliando as outras treze características de produção. As variáveis observadas foram agrupadas por meio de suas correlações e cada grupo de variáveis representa um fator. Depois de estimados os escores fatoriais foram feitas análises de superfície em função das combinações das doses de N, P e K. A análise fatorial pelo método dos componentes principais proporcionou redução de dez variáveis, relacionadas às características morfogênicas e estruturais do capim-milênio sob adubação, para três fatores com retenção de 79,07% da variação total dos dados e apenas 20,91% de perda de informação. O primeiro fator explicou 47,61% da variância total dos dados, correlacionando-se positivamente com as variáveis TApF (0,9114), TAlF (0,8907), TSF (0,8361), TAlC (0,7752) e negativamente com a variável FILO (-0,8851) e DVF (-0,8031). Em razão dos elevados coeficientes de correlação desses fatores convencionou-se denominá-los de características morfogênicas do capim-milênio (Fator CM). O segundo fator explicou 17,91% da variância total dos dados, apresentando correlação positiva com as variáveis NPerf (0,8954) e CFF (0,62155) e correlação negativa com a característica RFC (-0,7809) indicando que esse fator estaria associado às Características Estruturais dessa planta forrageira (Fator CE). O terceiro fator, denominado Número de Folhas Vivas (Fator NFV) do capim-milênio, explicou 13,54% da variância total dos dados e correlacionou-se exclusivamente de forma positiva com a característica NFV (0,8075). Os valores observados dos escores fatoriais das CM apresentaram tendência polinomial (P<0,01) e a análise de variância revelou significância (P<0,01) para as doses de N, K, bem como para a interação negativa entre as doses desses dois nutrientes aplicados. Não foi observado, para essas variáveis, efeito significativo do P. Os escores fatoriais estimados das CM apresentaram tendência linear crescente para as doses de N aplicadas e linear decrescente para as doses de K. Observou-se, no capimmilênio, resposta positiva das variáveis TApF, TAlF, TAlC e TSF (Fator CM) às doses de N. A DVF apresentou correlação negativa com as demais variáveis. O Fator CE variou significativamente (P<0,01) com as doses de N e K, sendo a interação entre os dois nutrientes não significativa (P>0,01). A equação de regressão polinomial apresentou ajuste ao modelo quadrático e linear crescente, em função das doses de N e K, respectivamente. Observou-se correlação negativa da variável RFC com as variáveis CFF e NPerf que compõem o Fator CE. O fator NFV foi influenciado significativamente (P<0,01) apenas pela adubação nitrogenada, ajustando-se ao modelo quadrático. Observou- se a partir da dose de 80 mg.dm-3 de N, aumento linear dos escores fatoriais estimados desse fator com o suprimento de N até a maior dose testada de 160 mg.dm-3. Para as variáveis relacionadas à produção do capim-milênio sob adubação, a análise fatorial pelo método dos componentes principais, proporcionou a redução de treze variáveis para três fatores, com retenção de 95,12% da variação total dos dados e apenas 4,88% de perda de informação. Observou-se que o primeiro fator, denominado Fator Produção Forrageira (Fator PF) do capim-milênio, explicou 43,99% da variância total dos dados correlacionando-se positivamente com as variáveis: MSF (0,9859), MSC (0,9930), MST (0,8493), PA (0,9966), PAMM (0,9913) conforme demonstrado por suas cargas fatoriais. O segundo fator, denominado fator Crescimento Forrageiro (Fator CF) do capim-milênio, explicou 34,92% da variância total dos dados e apresentou alta correlação positiva com as variáveis % Folha (0,9502), % Colmo (0,8827), RPAR (0,9205) e correlação negativa com a MSR (-0,74482) e % Raiz (-0,9669). O terceiro fator denominado, fator Forragem Senescente (FSen) do capim-milênio, correlacionou-se de forma positiva com MSMM (0,9063) e % MM (0,8809) e de forma negativa com a variável RPAMM (-0,9095). Os valores observados dos escores fatoriais da PF apresentaram tendência polinomial (P<0,01) e a análise de variância revelou significância (P<0,01) para as doses de K aplicadas, apresentando os escores fatoriais estimados desse fator tendência quadrática para esse nutriente. As interações entre os nutrientes N e P, entre N e K e entre P e K foram significativas (P<0,01), apresentando os escores fatoriais estimados para PF do capim-milênio tendência linear crescente para as três interações, respectivamente. A análise de variância para o fator CF não apresentou significância (P>0,01) para nenhum dos três nutrientes (N, P e K) estudados. Os valores observados dos escores fatoriais da FSen apresentaram tendência polinomial (P<0,01) e a análise de variância do mesmo revelou significância (P<0,01) para as doses de N e K aplicadas. Os escores fatoriais estimados do fator FSen apresentaram tendência quadrática, com ponto de máximo, para as doses de N aplicadas e tendência linear decrescente para as doses de K, sendo o maior escore fatorial estimado para esse fator observado na maior dose de N e menor de K.
42

Ação da casca de arroz queimada sobre nematoide da cenoura e atributos químicos do solo / Action of carbonized rice husk on carrot nematode and chemical soil attributes

Rosemari Kerber Aires 04 August 2014 (has links)
Dar destino adequado ao resíduo de casca de arroz e promover seu reúso é tarefa premente, em razão dos problemas gerados pelo descarte no ambiente ou uso indiscriminado na área agrícola, sem que se conheça sua influência na planta e no solo. Estudos sinalizam diversidade de usos da casca de arroz queimada. O resíduo contém alta concentração de silício (Si) e também outros nutrientes. Pesquisas com algumas culturas demonstram resposta positiva do uso de silício (Si) no controle de nematoides, patógeno que pode reduzir a produtividade e qualidade da cenoura (Daucus carota L.). Esta pesquisa foi realizada com o objetivo de conhecer a contribuição da casca de arroz queimada como alternativa à redução de danos por nematoides em cenoura e sua ação nos atributos químicos do solo. No primeiro capítulo avaliou-se o efeito da dose de casca de arroz queimada e do tempo de incubação sobre os atributos químicos do solo. No segundo capítulo avaliou-se o uso da casca de arroz queimada com diferentes tempos de incubação e do silicato de cálcio e magnésio nos atributos químicos do solo, concentração de nutrientes na cenoura, componentes da produção e produtividade de raízes. Os dois experimentos foram desenvolvidos em casa de vegetação no Departamento de Produção Vegetal da Esalq, Piracicaba/SP. No primeiro experimento foram usadas quatro doses de massa de matéria seca de casca de arroz queimada (zero, 0,65 g, 6,5 g e 13 g dm-3 de solo) em cinco tempos de incubação (zero, 25, 50, 75 e 100 dias), avaliadas em relação as alterações que promoveram no pH, matéria orgânica do solo (MOS), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg) e silício (Si). No segundo experimento avaliou-se a ação da dose de 13 gramas de massa de matéria seca de casca de arroz queimada por dm-3 de solo com três diferentes tempos de incubação, e do silicato de cálcio e magnésio na dose de cinco gramas por dm-3 de solo, sobre os atributos químicos do solo, concentração de nutrientes na cenoura, componentes de produção e produtividade, em relação ao dano por Meloidogyne javanica. Para tal o experimento foi montado com cinco tratamentos com inoculação de nematoides (CN): CAQ90AS-CN (casca de arroz queimada incubada 90 dias antes da semeadura); CAQ45ASCN (casca de arroz queimada incubada por 45 dias antes da semeadura); CAQ00DS-CN (casca de arroz queimada incorporada na semeadura); SILIC-CN (silicato de cálcio e magnésio); TEST-CN (testemunha, com nematoides) e outros cinco tratamentos com igual composição, porém sem inoculação de nematoides (SN): CAQ90AS-SN; CAQ45AS-SN; CAQ00DS-SN; SILIC-SN; TEST-SN. Constatou-se no primeiro experimento, que a casca de arroz queimada, disponibilizou potássio (K) em quantidades diretamente proporcionais a dose, independente do tempo de incubação ao solo. Houveram incrementos nos teores de fósforo (P) e silício (Si) do solo, de forma linear para dose e tempo de incubação. A casca de arroz queimada apresentou efeito residual para fósforo (P) e, especialmente, para silício (Si). No segundo experimento a aplicação de casca de arroz queimada, na dose de 13 g dm-3 de matéria seca incubada por 90 dias no solo aumentou a massa de matéria fresca de raízes comercializáveis em 3,9 vezes em relação a do tratamento testemunha, com manutenção da produtividade da cenoura em solo infestado por Meloidogyne javanica. O silicato de cálcio e magnésio aumentou o pH do solo, com consequente redução de absorção de Mn e Zn pela cultura, menor desenvolvimento das cenouras e diminuição da massa de matéria fresca de raízes comercializáveis. Nenhuma das fontes de silício (Si), nas doses usadas na pesquisa, aumentou significativamente a concentração do nutriente nas plantas de cenoura. / A proper destination of rice husk to reuse this residue is a pressing task due to the problems generated by the discharge into the environment or indiscriminate use in agriculture without knowing its influence on plant and soil. Studies indicate a variety uses of carbonized rice husk. The residue contains a high concentration of silicon and also other nutrients. Research shows for some crops positive response using silicon to control nematodes pathogen that can reduce the yield and quality of carrot (Daucus carota L.). The objective of this research was evaluate the contribution of the carbonized rice husk as an alternative to reduce damage by nematodes in carrots and action in soil chemical properties. In the first chapter we evaluated the effect of dose and time of incubation of carbonized rice husk on soil chemistry attributes. In the second chapter we evaluated the use of carobonized rice husk with different incubation times and calcium magnesium silicate in soil chemical properties, concentration of nutrients in carrots, yield components and yield of roots. The two experiments were conducted in a greenhouse at Department of Crop Science, Esalq, Piracicaba/SP. In the first experiment four doses of carbonized rice husk (zero, 0,65 g, 6,5 g and 13 g dm-3 of soil) in five incubation times (zero, 25, 50, 75 and 100 days) were compared to pH, organic matter soil, phosphorus, potassium, calcium, magnesium and silicon. The second experiment evaluated the action of 13 g dm-3 of soil of carbonized rice husk with three incubation times, and five g dm-3 of soil of calcium and magnesium silicate on soil chemical properties, nutrient concentration in carrots , yield components and yield in relation to damage by Meloidogyne javanica by the following treatments: CAQ90AS-CN (incubated 90 days before sowing); CAQ45AS-CN (incubated for 45 days before sowing); CAQ00DS- CN (incorporated at sowing ); SILIC -CN (Ca and Mg silicate) ; TEST- CN (control with nematodes) and the same treatments without inoculation of nematodes (CAQ90AS - SN; CAQ45AS - SN; CAQ00DS - SN; SILIC - SN and TEST - SN). Based on the results of the first experiment we found that carbonized rice husk released potassium (K) in amounts directly proportional to dose applied, regardless of the incubation time on the ground. There were increases in the levels of phosphorus (P) and silicon (Si) soil linearly with the dose and time of incubation. The carbonized rice husk had residual effect on phosphorus (P), especially for silicon (Si). In the second experiment the application of carbonized rice husk at dose of 13 g dm-3, dry matter incubated for 90 days in the soil increased the fresh weight of marketable yield by 3.9 times compared to the control treatment, with maintaining productivity carrot in soil infested with Meloidogyne javanica. Calcium silicate and magnesium increased soil pH, with consequent reduction of manganese (Mn) and zinc (Zn) uptake by the crop, less development of carrots and decreased fresh weight of marketable roots. No sources of silicon (Si), the doses used in the study, significantly increased the concentration of the nutrient in carrot plants.
43

Planering och styrning – med fokus på daglig styrning / Planning and management with focus on daily management

Lindelöf, Sara, Opseth, Mathilda January 2018 (has links)
Examensarbetet har inneburit iterationer för att ta reda på hur sektionen Research &amp; Development, Truck layout (RTL) på Scania kan förbättra planering och styrning för att säkra hög leveransprecision. RTL består av sju grupper som arbetar med chassiutveckling. Fler av grupperna på sektionen har börjat resan mot ett agilt arbetssätt för att öka sin flexibilitet och säkra sina leveranser. Det agila arbetssättet visar sig ha en positiv inverkan på leveranssäkerheten hos de grupper som lyckats med implementeringen. Inledningsvis observerades den dagliga styrningen, en gång hos varje grupp. För att ta reda på mer om gruppernas olika förutsättningar intervjuades respektive gruppchef. Fler av grupperna besöktes igen för att komplettera data om nuläget. En enkät skickades ut till medarbetarna på sektionen, svarsfrekvensen blev drygt 70 % och det konstateras att majoriteten svarade positivt i frågor om hur det är att arbeta i sin grupp. Däremot var de inte lika positiva kring hur stor nytta den dagliga styrningen bidrar med. En sprintplanering följdes hos den grupp som kommit längst med att arbeta agilt för att se hur planering av en fyra veckors sprint går till. Intervjuer hölls med sakkunniga för att få reda på mer om agilt arbete samt daglig styrning. Daglig styrning är ett av de forum som finns för planering och styrning, efter att ha studerat daglig styrning, sprintplanering samt teorier om agilt arbetssätt valde vi att fokusera examensarbetet på att optimera den dagliga styrningen. Utifrån observationer, intervjuer och teori kring agilt arbete samt daglig styrning användes kvalitetsverktyg. Utifrån två områden som kvalitetsverktygen resulterade i upptäcktes förbättringspotential för den dagliga styrningen. Syftet med daglig styrning måste klargöras samt regelbundet diskuteras hos samtliga grupper på RTL. De behöver även arbeta med fokus och hålla sig till sådant som är relevant för den dagliga styrningen / In order to find out how the Scania section RTL can improve planning and management to ensure high delivery precision this thesis work has consisted of iterations. The section Research Truck Layout (RTL) consists of seven groups that are working with chassis development. In order to increase their flexibility and secure their deliveries some of the groups have begun working towards agile methodologies. The agile methodologies has proven to have a positive impact on the delivery precision in the groups that succeeded with implementation. Initially, once in every group, the groups daily meetings was observed. In order to find out more about the groups different pre-requisite interviews were conducted with the group managers. Several of the groups were visited again to complete data about their current state. A survey was sent to the employees on the section, the response rate was over 70% and it showed that most employees had positive feeling towards working in their group. However, they were not as positive in regards to the benefits of daily management meetings. A followup was made on the group that was furthest along in working agile, the follow-up was made by observing the planning of a sprint. Interviews was held with experts to find out more about agile work as well as daily meetings. Daily management is a forum for planning and management, after studying daily management, sprint planning and theories of agile working methods, we chose to focus this thesis work on optimizing daily management. Based on observations, interviews, theories about agile methodologies and with the support of quality tools, two areas emerged which both have an improvement potential for a day-to-day management. The first area is the purpose of daily management, it has to be clarified and regularly discussed within all groups. The other area is focus, it needs to be worked on so that the meetings only contain topics that is relevant.
44

Creating a Video Resumé - With the Aid of Theories of Self-representation and Narratology

Nilsson, Maria January 2014 (has links)
Följande undersökning behandlar uppbyggnaden av en CV-film med utgångspunkt isociologen Erving Goffmans teori om identitet och självrepresentation samtfilmteoretikern David Bordwells teori om narratologi. Goffmans teori har använts föratt ta reda på vad som ska framställas i filmen medan Bordwells teori applicerats påfrågan om hur filmen ska framställas. Inom det teoretiska ramverket finns även StuartHalls teori om representation för att kunna belysa teorierna av Goffman och Bordwellutifrån ett gemensamt perspektiv. Fokusgruppmetoden har använts för att kvalitativtsamla information om vad en CV-film bör kommunicera till skillnad från ett skriftligtCV. Samt hur den bör utformas för att vara så användbar som möjligt.Resultatet visade att filmen inte bör vara längre än 2-3 minuter för att behållapublikens intresse. Vidare utmärkte sig kopplingen mellan platser, personliga sakeroch personen som framställs. Vems film det är och dennes egenskaper måste framgåtydligt, annars förlorar filmen sitt syfte. Undersökningen visade också på olika sätthur detta kan uppnås, exempelvis genom textning i filmen och ett väl föreberettmanus. En ny genre kan inte påstås ha uppkommit men däremot en början till ett nyttformspråk och definitivt något som kan utforskas vidare.
45

Assessment of the possible interactions between soil and plant water status in a Vitis vinifera cv. Merlot vineyard

Van Zyl, Albertus J. 12 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Irrigation scheduling decisions are based either on the direct measurement of soil water status (SWS) or on physiological measurements like plant water status (PWS). Soil based measurements are quick and easily automated, but the plant response for a particular quantity of soil moisture varies as a complex function of evaporative demand. A plant-based approach measures the plant stress response directly, but is an integration of environmental effects as well. In contrary to soil-based methods, plant based measurements can indicate when to irrigate, but not the quantity. Pre-dawn leaf water potential (ΨPD) is determined mostly by the soil moisture level, and can serve as a measure of static water stress in plants and an index of bulk soil water availability or even as an estimate of soil water potential at the root surface. Therefore it should be possible to establish a link between SWS and PWS, but it is largely unknown how stable the link in a heterogeneous vineyard would be, and how the grapevine vegetative and reproductive response relates to this link. Plant water status plays a large role in determining vigour and yield of the plant. The levels of PWS are influenced by irrigation, but it was mostly affected by the season and vine location in the vineyard. More negative plant water potentials reduced vigour, but had a less pronounced effect on yield, while also reducing overall wine quality. Vigour variability in the vineyard was largely attributed to soil heterogeneity, which seemed to have a strong effect on SWS. SWS measurements were calibrated according to the observed variability, increasing the accuracy of measurements significantly. Soil water content values were used to establish a link between SWS and PWS. This link was determined over time using nine plots, consisting of rain-fed and irrigated regimes, in variable vigour areas. A non-linear relationship was found between ΨPD and percentage extraction of plant available water for rain-fed plots. When irrigation was applied, no correlation could be found. In this study, for Merlot in the Stellenbosch region, PWS differences affected vigour, and to a lesser extent yield, as well as wine quality. More negative plant water potentials reduced vigour more in high vigour areas than in lower vigour areas, which in turn led to unbalanced vegetative: reproductive ratios. This disturbed vine balance may have had a bigger impact on wine quality than PWS levels. Therefore a well-managed and balanced vine is able to withstand more stress, with less detrimental effects. This study also highlights the danger of limiting the assessment of soil and plant water status conditions to point measurements in vineyards with high levels of vigour variability. / AFRIKAANSE OPSOMMING: Besluite rakende die skedulering van besproeiing word gewoonlik gebaseer op die direkte meting van grondwaterstatus (GWS), of op fisiologiese metings soos byvoorbeeld plantwaterstatus (PWS). Grond gebaseerde metings is relatief vinnig en maklik om te outomatiseer, maar die plantrespons vir ʼn spesifieke grondwaterinhoud varieer as ʼn komplekse funksie van dampdruktekorte. ‘n Plantgebaseerde benadering meet die plantstresreaksie direk, maar is ʼn integrasie van omgewingstoestande. In teenstelling met grondgebaseerde metodes, kan plantgebaseerde metodes aandui wanneer om te besproei, maar nie die hoeveelhede wat besproei moet word nie. Voorsonsopkoms blaarwaterpotensiaal (ΨPD) word grootliks deur die grondwaterinhoud bepaal, en kan as ʼn maatstaf van statiese waterspanning in plante en as ʼn indeks van bulk grondwaterbeskikbaarheid dien, of selfs as ʼn benadering van die grondwaterpotensiaal by die worteloppervlak. Dit behoort dus moontlik te wees om ʼn verwantskap te bepaal tussen GWS en PWS, maar dit is grootliks onbekend hoe stabiel hierdie verwantskap sal wees in ʼn heterogene wingerd, asook hoe die wingerdstok se vegetatiewe en reproduktiewe reaksie die verwantskap kan beïnvloed. Plantwaterstatus speel ʼn groot rol in die bepaling van groeikrag en opbrengs in die wingerdstok. Die vlakke van plantwaterstatus word deur besproeiing beïnvloed, maar word skynbaar meesal deur die seisoen en wingerdstok se ligging in die wingerd bepaal. Meer negatiewe plantwaterpotensiaalvlakke het gelei tot laer groeikrag, maar het ʼn minder uitgesproke effek gehad op opbrengs, terwyl dit in die algemeen wynkwaliteit verswak het. Groeikrag variasie in die wingerd kon grootliks aan grond heterogeniteit toegeskryf word, wat skynbaar ʼn sterk invloed op grondwaterstatus gehad het. Grondwaterstatus metings is gekalibreer volgens die variasie wat waargeneem is, wat die akkuraatheid van metings beduidend verhoog het. Grondwaterinhoud waardes is gebruik om ʼn verwantskap aan te dui tussen SWS en PWS. Hierdie verwantskap is oor tyd bepaal vir nege persele, wat bestaan het uit droëland asook besproeide persele, in areas waarvan die groeikrag verskil het. ʼn Nie-liniêre verband is gevind tussen ΨPD en die persentasie onttrekking van plantbeskikbare water vir die droëland persele. Waar besproei was, kon geen verband gevind word nie. In hierdie studie, vir Merlot in die Stellenbosch area, het PWS vlakke groeikrag en tot ʼn mindere mate opbrengs en wynkwaliteit beïnvloed. Meer negatiewe plantwaterpotensiaal vlakke het groeikrag meer beïnvloed in hoër groeikrag areas as in die laer groeikrag areas, wat ook gelei het tot ongebalanseerde vegetatiewe:reproduktiewe verhoudings. Hierdie versteurde balans in die wingerdstokke kon dalk ʼn groter impak op wynkwaliteit gehad het as PWS vlakke. Daar moet dus gepoog word om goed bestuurde en gebalanseerde wingerdstokke te hê, sodat strestoestande beter weerstaan kan word met minder nadelige gevolge. Die studie beklemtoon ook die gevaar verbonde daaraan om die bepaling van grond- en plantwaterstatus te beperk tot puntmetings in wingerde met groot variasie in groeikrag.
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Adsorption dans un milieu carboné lamellaire nanoporeux : simulation Monte Carlo Grand Canonique, synthèse et caractérisation / Adsorption in a slit nanoporous carbon medium : Grand Canonical Monte Carlo simulation, synthesis and characterization

Nguemalieu Kouetcha, Daniella 21 December 2017 (has links)
Les carbones désordonnés nanoporeux sont des supports efficaces pour le piégeage de polluants y compris à l’état de traces dans les eaux usées. Le phénomène d’adsorption à l’origine de la rétention des molécules est cependant complexe car dépendant d’une multitude de facteurs : structure, morphologie et charge de la surface carbonée d’une part,taille/forme et polarité de la molécule d’autre part, l’ensemble étant dépendant du pH et de la concentration. Pourune meilleure compréhension du phénomène, il est important de pouvoir étudier séparément certains paramètres.Dans la perspective d’étudier le phénomène d’adsorption en milieu aqueux sur des carbones nanoporeux à structure et morphologie modèle, des structures lamellaires nanoporeuses de type carbone turbostratique ont été générées numériquement en langage C++ avec le calcul de la fonction de distribution radiale ou de paires. L’adsorption gazeuse d’une molécule non polaire ou polaire puis de deux molécules polaires (H2O/CO2) et (H2O/C6H6O)a été simulée par la méthode Grand Canonique Monte Carlo sur ce support modèle (Isotherme d’adsorption,chaleur d’adsorption, densité des molécules adsorbées) en fonction de la température. Les temps de calcul ont été drastiquement diminués en développant des codes parallèles optimisés sous MPI C++. L’influence de la forme etde la distribution en taille des pores a été mise en évidence en simulant l’adsorption sur la structure d’un carbone activé déjà obtenue par reconstruction 3D de type RMC. Enfin, d’un point de vue expérimental, l’intercalation d’ions tetraalkylammonium par voie électrochimique dans des carbones lamellaires (HOPG et graphite) a été explorée en vue d’obtenir des carbones lamellaires nanoporeux (≈1 nm). La structure a été caractérisée par diffraction des rayons X. / Disordered nanoporous carbons are the good materials for capturing pollutants, including traces in wastewater. The phenomenon of adsorption at the origin of the retention of molecules is complex. However, depending on a multitude of factors : structure, morphology and loading of the carbonaceous surface, on the one hand, size/shapeand polarity of the molecule, on the other hand, the whole being dependent on pH and concentration. For a better understanding of the phenomenon, it is important to be able to study some parameters separately. In order to study the phenomenon of adsorption in aqueous medium on nanoporous carbons with structure and model morphology, nanoporous slit structures of turbostratic carbon type were generated numerically in C ++ language with thecalculation of the radial distribution function or pairs. The gas adsorption of a nonpolar or polar molecule and then oftwo polar molecules (H2O/CO2) and (H2O/C6H6O) was simulated by Grand Canonical Monte Carlo method on this model support (adsorption isotherm, adsorption heat, density of adsorbed molecules) as a function of temperature.The runtime has been drastically reduced by developing parallel codes optimized under MPI C ++. The influence of the shape and the pore size distribution was demonstrated by simulating the adsorption on the structure of an activated carbon already obtained by 3D reconstruction of the RMC type. Finally, from an experimental point of view, the intercalation of tetraalkylammonium ions electrochemically in slit carbons (HOPG and graphite) was explored in order to obtain nanoporous lamellar carbons ( ≈1 nm). The structure was characterized by X-ray diffraction.
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The Social Framework of Individual Decisions

Gerlach, Philipp 19 January 2018 (has links)
Wann und warum verhalten sich Menschen ethisch (in-)korrekt? Die vorliegende Dissertation fasst allgemeine Theorien und experimentelle Befunde (nicht-)kooperativen, (un-)fairen und (un-)ehrlichen Verhaltens zusammen. Hierzu führt Kapitel 1 experimentelle Spiele als rigoroses Instrument zur Untersuchung (un-)ethischen Verhaltens ein. Kapitel 2 zeigt, dass sich kleine Veränderungen in der kontextuellen Rahmung von experimentellen Spielen langanhaltend auf die Kooperationsneigung der Teilnehmer auswirken können. Kontextuelle Rahmungen verändern zudem Verhaltenserwartungen sowie Aufteilungen in nicht-strategischen Situationen. Diese Effekte sind durch Theorien sozialer Normen erklärbar. Kapitel 3 ergründet, warum sich Studierende der Wirtschaftswissenschaften teils egoistischer verhalten als ihre Kommilitonen. Theorien sozialer Normen werden hierbei um die Bereitschaft erweitert, Nonkonformität mittels Sanktionen zu erzwingen. Es wird gezeigt, dass sich Studierende der Wirtschaftswissenschaften und anderer Fächer in ihren Aufteilungsentscheidungen ähnlich häufig mit Fairness beschäftigen und zu ähnlichen Einschätzungen kommen, welche Aufteilung als fair gilt. Sie teilen jedoch weniger großzügig und erwarten dies auch von anderen. Zudem sind sie weniger bereit, als unfair angesehene Aufteilungen zu sanktionieren. Es wird argumentiert, dass sich Studierende der Wirtschaftswissenschaften egoistischer verhalten, weil sie nicht daran glauben, dass sich andere an eine grundsätzlich geteilte Fairnessnorm halten. Kapitel 4 zeigt, dass intrinsische Sanktionen (wie Scham und Schuld) ausreichen, damit sich Menschen ethisch korrekt verhalten. Das Kapitel bietet zahlreiche Antworten zu aktuellen Debatten, wer sich unter welchen Umständen (un-)ehrlich verhält. Es wird gezeigt, dass Ehrlichkeit sowohl von situativen Einflüssen (z.B. Anreizen und Externalitäten) wie von persönlichen Aspekten (z.B. Geschlecht und Alter) und letztlich auch vom experimentellen Paradigma abhängt. / When and why do people engage in (un)ethical behavior? This dissertation summarizes general theories and synthesizes experimental findings on (non)cooperation, (un)fairness, and (dis)honesty. To this end, Chapter 1 introduces experimental games as a rigorous tool for studying (un)ethical behavior. Chapter 2 demonstrates that small changes in the framing of context (e.g., referring to a social dilemma as a competition vs. a team endeavor) can have long-lasting effects on the participants’ propensity to cooperate. Context framing also shapes beliefs about the cooperative behavior of interaction partners and donations in non-strategic allocation decisions. Taken together, the results suggest that social norm theories provide a plausible explanation for cooperation, including its sensitivity to context framing. Chapter 3 investigates why experimental games regularly find that economics students behave more selfishly than their peers. The concept of social norms is thereby extended to include the enforcement of compliance per sanctions. The results indicate that economics students and students of other majors are about equally concerned with fairness and they have similar notions of fairness in the situation. However, economics students make lower allocations, expect others to make lower allocations, and are less willing to sanction allocations seen as unfair. Skepticism mediated their lower allocations, suggesting that economics students behave more selfishly because they expect others not to comply with a shared fairness norm. Chapter 4 shows that intrinsic sanctions (e.g., shame and guilt) can be sufficient for ethical behavior to emerge. The chapter provides answers to many of the ongoing debates on who behaves dishonestly and under what circumstances. The findings suggest that dishonest behavior depends on situational factors (e.g., reward magnitude and externalities), personal factors (e.g., gender and age) as well as on the experimental paradigm itself.
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Ecological rationality of social learning

Barkoczi, Daniel 30 March 2016 (has links)
Wie Menschen von anderen lernen und wann es adaptiv-rational ist sich auf soziales Lernen zu verlassen sind wichtige Fragen in vielen Disziplinen einschließlich der Psychologie, der Biologie, der Anthropologie und den Wirtschaftswissenschaften. Trotz der geteilten Interessen dieser Disziplinen sind viele der vorhandenen Resultate voneinander isoliert und oft nicht vergleichbar, teilweise weil es der Forschung zum sozialen Lernen immer noch eines theoretischen Rahmens fehlt, welcher die gewonnen Erkenntnisse vergleichbar machen würde sowie erklären würde warum unterschiedliche Strategien in Abhängigkeit vom sozialen Kontext erfolgreich sind oder nicht. In meiner Arbeit schlage ich einen solchen theoretischen Rahmen vor, welcher sich auf der Forschung zur ökologischen Rationalität gründet. Ich benutze den theoretischen Rahmen der ökologischen Rationalität sozialen Lernens, um drei Fragen zu beantworten: i) Wie können soziale Lernstrategien als kognitiv plausible Strategien modelliert werden, die auf drei einfachen Building Blocks beruhen (Such-, Stopp- und Entscheidungsregeln), ii) was sind die wichtigsten Faktoren von sozialen Umwelten und Problemumwelten, in denen soziales Lernen stattfindet und iii) wie interagieren soziale Lernstrategien, die auf unterschiedlichen Building Blocks beruhen, mit der Struktur von Umwelten, um unterschiedliche Erfolgsniveaus zu erreichen. Indem ich diese drei Fragen adressiere, erarbeite ich die Bedingungen unter denen unterschiedlichen Strategien adaptiv-rational sind und erkläre wie unterschiedlichen Strategien in bestimmten Umwelten erfolgreich sind. Jedes der Kapitel behandelt eine wichtige alltägliche soziale Lernsituation, identifiziert die Schlüsselcharakteristiken der Situation und demonstriert wie die Building Blocks des sozialen Lernens mit diesen Umweltstrukturen interagieren, um unterschiedliche Erfolgsniveaus zu erreichen. / How people learn from others and when it is adaptive to rely on social learning have been major questions in several disciplines including psychology, biology, anthropology and economics. Despite the shared interest of these diverse fields, many of the results remain isolated and are often incomparable, in part because the study of social learning still lacks a general theoretical framework that would make results comparable or explain why different strategies perform well in different contexts. In this thesis I propose such a framework that is grounded in the study of ecological rationality. I use this frame- work to explore three primary questions: i) how can social learning strategies be modeled as cognitively plausible strategies composed of simple building blocks (search, stopping and decision rules), ii) what are key characteristics of social and task environments in which social learning takes place, and iii) how do social learning strategies composed of different building blocks interact with the structure of the environment to produce different levels of success. Through addressing these three questions I map out the conditions under which different strategies are adaptive and explain how the building blocks of different strategies contribute to their performance in certain environments. The thesis focuses on three representative classes of social learning strategies, namely, frequency-dependent, payoff-biased, and unbiased copying. Different chapters focus on important everyday social learning settings, identify key environmental characteristics defining the setting and demonstrate how the building blocks of social learning strategies interact with these environmental structures to produce different outcomes.
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Bortsorterad? : Två professioners syn på konsekvenserna av automatisk klassificering inom rekrytering / Sorted out? : Two professions’ views on the consequences of automatic classification within recruitment

Klingborg, Jenny January 2019 (has links)
To classify is human. Whether intentionally or not, we classify the world around us, though not all classification has the same level of impact. Throughout history and well into modern day, classification of people, from the apartheid regime in South Africa to gender classification of trans people, has had significant and sometimes devastating impact on individuals. This bachelor thesis examines the views of developers and recruiters regarding automatic classification of CVs within recruitment, and how these differ. Nine interviews with twelve informants – three developers and nine recruiters – form the empirical base of the thesis. A thematical analysis is applied and the results are presented in relation to the everyday consequences in Geoffrey C. Bowker and Susan Leigh Star’s (1999) theoretical perspective. Three main topics are discerned as common themes in the interviews: time saving, precision, and reliability. The differing focus on each theme in the respective professions is further discussed. The width of the study does not allow for a generalised view of the opinions of each profession but provides an interesting starting point for further studies within the field.
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Desenvolvimento, produção e qualidade de frutos de abacateiro cv. \"Hass\" sobre dois porta-enxertos nas condições edafoclimáticas da região central do Estado de São Paulo / Growth, fruit yield and quality of \'Hass\' avocado budded onto two rootstocks in the central region of São Paulo State

Ana Flávia Garcia Moraes 10 September 2014 (has links)
A produção comercial brasileira de abacates ocorre em pomares implantados sobre porta-enxertos oriundos de sementes, o que resulta em grande desuniformidade das plantas com relação a tamanho da copa, produção, qualidade de frutos e suscetibilidade a patógenos do solo, principalmente Phytophthora cinnamomi, agente causal da podridão radicular, principal doença da cultura. Enquanto em outros países já é adotado o uso de porta-enxertos com características superiores que são propagados clonalmente visando minimizar esses problemas, no Brasil estes materiais ainda não foram avaliados. Durante os anos de 2010 a 2013 foi conduzido um experimento na Fazenda Jaguacy, município de Bauru, SP, com o objetivo de avaliar o desenvolvimento, produção e qualidade de frutos de abacateiro \'Hass\' sobre dois porta-enxertos, sendo um proveniente de sementes (\'Seedling\') (T1) e o outro da cultivar Dusa obtido por propagação clonal (T2). O experimento foi conduzido seguindo um delineamento em blocos casualizados, com dois tratamentos, 5 repetições e 10 plantas por parcela, totalizando 100 plantas em avaliação. O desenvolvimento vegetativo foi obtido pela medição da altura e diâmetro das plantas, utilizados para o cálculo do volume de copa. A produção foi avaliada a partir da contagem e pesagem de todos os frutos de cada planta e também pelo cálculo da eficiência produtiva e da alternância produtiva entre anos. A qualidade dos frutos foi avaliada a partir da massa, diâmetro e comprimento individual de uma amostra de 200 frutos por tratamento. Os dados foram submetidos à análise da variância, considerando nível de significância de 5%. Nenhuma diferença significativa foi observada entre os tratamentos para volume de copa, produção média, produção acumulada e número de frutos. Para as variáveis de eficiência produtiva, massa, comprimento, diâmetro e relação C:D de frutos ocorreram diferenças significativas que indicaram a superioridade do porta-enxerto clonal \'Dusa\' para plantas de \'Hass\' quando comparadas ao \'Seedling\'. / Avocado production in Brazil takes place in orchards established onto Seedling rootstocks, with large heterogeneity among plants regarding tree size, fruit yield and quality and susceptibility to soil pathogens, mainly Phytophthora cinnamomi that causes avocado root rot and is by far the main disease affecting this crop worldwide. While clonally obtained rootstocks are used in other countries to minimize such disadvantages, in Brazil such materials have not been yet evaluated. During 2010 to 2013 a trial was conducted in Fazenda Jaguacy farm, in Bauru county, with the aim to evaluate plant growth, fruit yield and quality of \'Hass\' avocados onto two rootstocks, a Seedling type (T1) and the \'Dusa\' clonal rootstock (T2). The trial was established after a completely randomized block design, with two treatments, 5 repetitions and 10 trees per plot, with a total of 100 measured trees. Tree size was evaluated by measurements of plant height and diameter, which were utilized to compute canopy volume. Fruit yield was obtained from counting and weighing all the fruits harvested at once from each tree, and also the yield efficiency and alternate bearing index were calculated. Fruit quality was determined from individual measurements of fruit weight, diameter (D) and length (L) on a 200-fruit sample randomly collected from each rootstock. Data was submitted to analysis of variance with a 5% significance level. No significant differences were observed among treatments for canopy volume, mean fruit yield, cumulative yield and fruit number. There were significant differences for yield efficiency, fruit weight, length, diameter and L:D ratio supporting the better performance of \'Dusa\' clonal rootstock on \'Hass\' scion as compared to the Seedling rootstock.

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