972 resultados para ISOELECTRIC PRECIPITATION


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Dissertação de mestrado em Ordenamento e Valorização de Recursos Geológicos

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The vulnerability to pollution and hydrochemical variation of groundwater in the mid-west karstic lowlands of Ireland were investigated from October 1992 to September 1993, as part of an EU STRIDE project at Sligo Regional Technical College. Eleven springs were studied in the three local authority areas of Co. Galway, Co. Mayo, and Co. Roscommon. Nine of the springs drain locally or regionally important karstic aquifers and two drain locally important sand and gravel aquifers. The maximum average daily discharge of any of the springs was 16,000 m3/day. Determination of the vulnerability of groundwater to pollution relies heavily on an examination of subsoil deposits in an area since they can act as a protecting or filtering layer over groundwater. Within aquifers/spring catchments, chemical reactions such as adsorption, solution-precipitation or acid-base reactions occur and modify the hydrochemistry of groundwater (Lloyd and Heathcote, 1985). The hydrochemical processes) that predominate depend cm the mineralogy of the aquifer, the hydrogeological environment, the overlying subsoils, and the history of groundwater movement. The aim of this MSc research thesis was to investigate the hydrochemical variation of spring outflow and to assess the relationship between these variations and the intrinsic vulnerability of the springs and their catchments. If such a relationship can be quantified, then it is hoped that the hydrochemical variation of a spring may indicate the vulnerability of a spring catchment without the need for determining it by field mapping. Such a method would be invaluable to any of the three local authorities since they would be able to prioritise sources that are most at risk from pollution, using simple techniques of chemical sampling, and statistical analysis. For each spring a detailed geological, hydrogeological and hydrochemical study was carried out. Individual catchment areas were determined with a water balance/budget and groundwater tracing. The subsoils geology for each spring catchment were mapped at the 1:10,560 scale and digitised to the 1:25,000 scale with AutoCad™ and Arclnfo™. The vulnerability of each spring was determined using the Geological Survey's vulnerability guidelines. Field measurements and laboratory based chemistry analyses of the springs were undertaken by personnel from both the EPA Regional Laboratory in Castlebar, Co. Mayo, and the Environment Section of Roscommon Co. Council. Electrical conductivity and temperature (°C) were sampled fortnightly, in the field, using a WTW microprocessor conductivity meter. A percentage (%) vulnerability was applied to each spring in order to indicate the areal extent of the four main classes of vulnerability (Extreme, High, Moderate, and Low) which occurred within the confines of each spring catchment. Hydrochemical variation for the springs were presented as the coefficient of variation of electrical conductivity. The results of this study show that a clear relationship exists between the degree of vulnerability of each catchment area as defined by the subsoil cover and the coefficient of variation of EC, with the coefficient of variation increasing as the vulnerability increases. The coefficient of variation of electrical conductivity is considered to be a parameter that gives a good general reflection of the degree of vulnerability occurring in a spring catchment in Ireland's karstic lowlands.

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გამოკვლეულია ატმოსფერული ნალექების ჯამურ მინერალიზაციაზე მიწისპირა ჰაერის ტემპერატურის გავლენა. შედგენილია ასეთი დამოკიდებულების რეგრესიის განტოლება მეოთხე რიგის პოლინომის სახით. გამოთვლილია აპროქსიმაციის საიმედობის კოეფიციენტი და კორელაციის ინდექსი.

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სტატისტიკურად უზრუნველყოფილ ექსპერიმენტულ მასალაზე დაყრდნობით განსაზღვრულია საქართველოს კახეთის რეგიონის თბილი სეზონის ატმოსფერული ნალექების ინტენსივობასა და რადიოლოკაციურ ამრეკვლადობას შორის დამოკიდებულების წრფივი რეგრესიის განტოლების მუდმივი კოეფიციენტები, აგრეთვე გამოთვლილია აპროქსიმაციის საიმედობის მაჩვენებლის მნიშვნელობა

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ნაშრომში გაანალიზებულია ელჭექის ღრუბლების რადიოლოკაციურ ამრეკვლადობაზე (Z) დაკვირვირვების მონაცემები და მათგან მოსული ნალექების ინტენსივობის (I) შორის დამოკიდებულება.

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გაანალიზებულია საქართველოს კახეთის რეგიონის ერთუჯრედიანი კონვექციური ღრუბლების მაქსიმალური რადიოლოკაციური ამრეკვლადობის (Z) და ამ ღრუბლებიდან მოსული ნალექების საშუალო ინტენსივობის (I) შესახებ მონაცეები. სტატისტიკური ამონაკრების მოცულობამ შეადგინა 460 შემთხვევა.

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აღმოსავლეთ საქართველოს ატმოსფერული ნალექების ქიმიური ანალიზის მონაცემების შესწავლის შედეგად დადგენილია, რომ ამ ნალექებში მთავარი იონების და მათი ჯამური კონცენტრაციები იცვლება იმ უნალექო 12 საათიანი დროის ინტერვალის რიცხვის მიხედვით, რომელიც წინ უსწრებდა გაანალიზებული სინჯის აღებას. დამოკიდებულება ზრდადია და კარგად აღიწერება მესამე რიგის პოლინომით. ყველა იონისათვის გამოთვლილია ემპირიულ დამოკიდებულებაში შემავალი მუდმივი კოეფიციენტი.

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სტატიაში გამოკვლეულია აღმოსავლეთ საქართველოს ატმოსფერულ ნალექებში ზოგიერთი იონებისა და მიკროელემენტების კონცენტრაციები ატმოსფერული პროცესების ტიპებთან და ღრუბლებზე აქტიური ზემოქმედების მასშტაბთან დამოკიდებულებაში. ამასთან ერთად დადგენილია მოცემული რეგიონისათვის ხსენებული იონებისა და მიკროელემენტების კონცენტრაციათა ფონური მნიშვნელობები.

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Irish potato tubers imported from Holland and Germany were planted at the Instituto Agronômico Experiment Station, Campinas, in April, 1955. At digging time, in July, 1955, the tubers were found to be injured by nematodes belonging to the genus Ditylenchus. No visible symptoms were found on the plants during the growing season, since the nematodes did not attack the stems. However, prevailing weather conditions from April to July were not favorable for nema activities, with low temperature and rain precipitation. Therefore, it does not seem safe to assume that, as a rule, the nemas do not attack buds and stems, for further observations may reveal such an occurrence, as it has been reported in the literature. The injury was characterized by spots consisting of decaying brown tissue, the nematodes being found mainly between this and the uninjured tissue. Larvae and adults occurred simultaneously. Fourteen different potato varieties were attacked by the nematodes, the percentage of disfigured tubers ranging from 6 (vars. Irene, Barima and Tedria) to 38 (var. Stamm 456). Studies en the morphology cf the parasites disclosed that two different Ditylenchus forms were present, with Apheten-chus sp. and Aphelenchoides sp. associated with them. The writers have not yet drawn a final conclusion about the identification of the Ditylenchi. However, it was clearly seen that no form can be identified either with D. dipsaci or with D. destructor. Both forms have lateral fields made up of 6 incisures, what separates them from D. dipsaci. On the other hand, measurements as well as some details in the organization of the oesophagus make the identification with D. destructor quite impossible. As far as the origin of the parasites is concerned, the fact that they could not be determined either as D. dipsaci or as D. destructor emphasizes the possibility of being two native species, not introduced with the tubers imported.

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The plastral spotting variation in the chelid turtle Phrynops hilarii (Duméril & Bibron, 1835) in relation to sex, size, and geographic procedence of individuals was analyzed. States for qualitative characters were analyzed using non-parametric tests. Quantitative characters (shell and scute measurements) were standardized for body size by linear regression against carapace length, and were subjected to principal components analysis and canonical discriminant function analysis. Results suggest that increased plastral spotting is a polymorphic ontogenetic trait in P. hilarii. Neither hatchlings nor juveniles have plastral pattern moderately or heavily pigmented. The simplest pattern, however, may persist without changes in some adults. There are no differences between sexes. The spatial distribution of the plastral pattern is not ordered latitudinally or longitudinally, showing no relationship with gradients of elevation, temperature, or precipitation. This pattern trait lacks of taxonomic significance. The morphometric analysis failed to reveal any character of diagnostic utility in the plastron to support the possibility that these patterns correspond to different sympatric taxa.

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The reproductive pattern of Elachistocleis bicolor (Guérin Méneville, 1838) was studied at Serra da Bodoquena, from October 2000 to September 2001. Reproduction occurred in the wet season (October to April) and was correlated to high continuous pluviometric precipitation. The species presents sexual size dimorphism, with females larger than males. The number of mature eggs per ovary was 620 ± 251 (n=39) and mature eggs measured 1.15 ± 0.30 mm (n=40). Elachistocleis bicolor presented significant relations between snout-vent length and number of mature eggs (n=39; r²=0.25; p=0.001), individual weight and number of mature eggs (n=41, r²=0.30; p=0.002), snout-vent length and ovarian weight (n=35; r²=0.47; p<0.01), and individual weight and ovarian weight (n=36; r²=0.55; p<0.01). Weight and volume are better to study size-fecundity relationships than snout-vent length. The females invested 22.7 ± 6.3 % (n=35) of their weights in reproduction and the variance associated to this variable was high, related to the reproductive mode of the species.