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Influência de fatores estruturais e químicos no colapso e dispersão de dois solos / not availableAna Carina Zanollo Biazotti Collares 08 May 2002 (has links)
Certos solos não saturados ao serem umedecidos experimentaram bruscas reduções de volume, sob cargas praticamente constantes. O fenômeno é atribuído a um colapso de estrutura do solo, donde a designação de solo colapsível. Essa redução de volume pode ocorrer sob a ação do próprio peso do solo, mas é mais comum ocorrer quando o solo está sujeito a um carregamento adicional. Muitos dos problemas de recalques nas áreas urbanas e industrias na Região Sudeste do Brasil estão associados ao colapso dos solos. Deformações induzidas por umedecimento (colapso) têm sido reportados como decorrrentes de vazamentos oriundo das redes de esgoto e de abastecimento de água. Porém, pouco se sabe sobre a influência de vazamentos de diferentes efluentes químicos nesse fenômeno e em outros fenômenos eventualmente associados com a dispersão dos solos. Neste trabalho, analisa-se o comportamento colapsível de dois solos típicos do interior do Estado de São Paulo, considerando diferentes soluções como líquido inundante. Utilizaram-se substâncias orgânicas e inorgânicas com o intuito de verificar a interferência de algumas propriedades químicas destas soluções (pH, constante dielétrica, concentração e temperatura) no comportamento colapsível dos solos. Para evitar a ação dos fluídos químicos na dispersão dos solos, realizou-se o \"pinhole test\". Análises porosimétricas por intrusão de mercúrio foram utilizadas para identificar mudanças ocorridas nos poros das amostras após os ensaios edométricos. Para a análise estrutural, foram analisadas lâminas delgadas em microscópio óptico. Verificou-se que a presença de um agente dispersivo na solução tende a influenciar o potencial de colapso dos solos. A constante dielétrica, o pH e a concentração mostraram-se influentes para alguns fluídos de saturação. Os resultados dos \"pinholes tests\" revelaram que o fluxo das diferentes soluções não provocou a dispersão do solo. Ensaios de porosimetria ) por intrusão de mercúrio indicaram que as deformações por colapso resultam de uma redução do volume de macroporos. A análise das lâminas delgadas mostrou diferentes facetas dos processos ocorrentes em nível estrutural, como diminuição considerável dos poros e modificações no plasma para as amostras inundadas com as soluções defloculantes de hexametafosfato de sódio e hidróxido de sódio. / Some non saturated soils show considerable volume reduction when wetted under constant loads. The phenomenon is attributed to soil structure collapse, thus the designation collapsible soils;. Volume reduction upon wetting can arise under soil self weight, but it is more common when the soil is subjected to an additional load. Many settlement problems in urban and industrial areas in Southern Brazil are associated to soil collapse. Wetting induced strains (collapse) have been related to water and sewer leakage. However little is known about the influence of different effluent leakage from industrial plants in the phenomenon and in other related phenomenon such as soil dispersion. This work deals with the collapsible behavior of two typical soils from the state of São Paulo assessed by means of wetting both soils with different chemical solutions. Organic and inorganic solutions were applied, aiming to verify the interference of some physic-chemical properties of the solutions (pH, dielectric constant, concentration, temperature) in the collapse behavior of the soils. The soil dispersion was evaluated through pinhole tests, where the same solutions used in the collapse tests were applied in the leaching procedures. Thin sections and mercury porosimetry of the soils were used to study the soil structural features. It is shown that the dielectric constant and the pH tends to influence the collapse potential of the soils when some solutions are concerned. Mercury intrusion tests have revealed that collapse deformations are related to macropores volume reduction. Thin sections have shown some features of the occurring processes on a structural levei, such as pore reductions and changes in fine matrix for the soil samples soaked with sodium hexametaphosphate and sodium hydroxide solution.
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Relation entre propriétés rhéologiques et structure microscopique de dispersions de particules d'argile dans des dispersions de polymères / Relations between rheological properties and microscopique structure of clay particle dispersions in polymer solutionsBen Azouz, Kaouther 09 November 2010 (has links)
L'argile est utilisée avec des polymères en solution dans de nombreuses applications telles que les boues de forage ou encore pour rendre les fibres textiles résistantes au feu. Du fait de la structure très particulière des particules d'argile, avec plusieurs échelles d'association de feuillets, les propriétés rhéologiques de dispersions d'argile dans des solutions de polymère dépendent fortement de l'histoire mécanique du matériau. Une étude de vieillissement des dispersions d'argile dans les solutions aqueuses de CMC a montré l'effet du temps, en particulier sur l'existence d'un seuil de contrainte et son évolution. Les mesures rhéologiques mettent en évidence des comportements de type « gel ». Ils résultent de la formation, au sein du fluide, de réseaux élastiques de nature différente selon la phase continue utilisée. Dans l'eau, les particules partiellement exfoliées s'associent entre elles selon des mécanismes qui dépendent du pH. Alors que dans la solution de polymère, il semble que des agrégats de particules soient connectés entre eux par l'intermédiaire des chaînes macromoléculaires. L'influence de la température et du pH sur les propriétés rhéologiques a été examinée. Plusieurs expériences indépendantes ont montré une évolution non monotone des caractéristiques mécaniques des fluides lorsque la température augmente. Ceci peut s'expliquer en invoquant un accroissement de la mobilité des chaînes favorisant l'ouverture des agrégats se dissociant en agrégats de plus petite taille. Le contrôle du pH quant à lui permet de modifier les interactions particule-particule et particule-polymère et, de ce fait, d'agir sur les propriétés mécaniques des gels formés. / The clay is used with polymer solutions in numerous applications such as drilling muds or to make textile fibers fireproof. Because of the very particular structure of the clay particles, with several scales of association of platelets, the rheological properties of clay dispersions in aqueous polymer solutions strongly depend on the mechanical history of the material. An ageing study of clay dispersion in aqueous CMC solutions showed the effect of time, in particular on the existence of a yield stress and its evolution. The rheological measurements display gel like behaviours. They are the result of formation, within the fluid, of different kind of networks, depending on the continuous phase. The partially exfoliated particles join together according to mechanisms which depend on the pH. While in the polymer solution, it seems that particle aggregates are connected through the macromolecular chains. The influence of the temperature and the pH on the rheological properties is studied. Several independent experiments show a non-monotonous evolution of the mechanical properties of the fluids as the temperature increases. It may be due to an increase of the mobility of the macromolecular chains favouring the dissociation of the particles aggregates. The control of the pH allows the particle-particle and particle-polymer interactions to be modified and to therefore act on the mechanical properties of the gels.
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Departure processes from MAP/PH/1 queuesGreen, David Anthony January 1999 (has links)
A MAP/PH/1 queue is a queue having a Markov arrival process (MAP), and a single server with phase-type (PH -type) distributed service time. This thesis considers the departure process from these type of queues. We use matrix analytic methods, the Jordan canonical form of matrices, non-linear filtering and approximation techniques. The departure process of a queue is important in the analysis of networks of queues, as it may be the arrival process to another queue in the network. If a simple description were to exist for a departure process, the analysis of at least feed-forward networks of these queues would then be analytically tractable. Chapter 1 is an introduction to some of the literature and ideas surrounding the departure process from MAP/PH/1 queues. Chapter 2 sets up the basic notation and establishes some results which are used throughout the thesis. It contains a preliminary consideration of PH -type distributions, PH -renewal processes, MAP s, MAP/PH/1 queues, non-linear filtering and the Jordan canonical form. Chapter 3 is an expansion of "The Output process of an MMPP/M/1 queue", where the question of whether a MAP description can exist for the departure process of a non-trivial MAP/M/1 queue is considered. In a 1994 paper, Olivier and Walrand conjectured that the departure process of a MAP/PH/1 queue is not a MAP unless the queue is a stationary M/M/1 queue. This conjecture was prompted by their claim that the departure process of an MMPP/M/1 queue is not MAP unless the queue is a stationary M/M/1 queue. We show that their proof has an algebraic error, which leaves open the above question of whether the departure process of an MMPP/PH/1 queue is a MAP or not. In Chapter 4, the more fundamental problem of identifying stationary M/M/1 queues in the class of MAP/PH/1 queues is considered. It is essential to be able to determine from its generator when a stationary MAP is a Poisson process. This does not appear to have been discussed in the literature prior to the author's paper, where this deficiency was remedied using ideas from non-linear filtering theory, to give a characterisation as to when a stationary MAP is a Poisson process. Chapter 4 expands upon "When is a MAP Poisson". This investigation of higher order representations of the Poisson process is motivated by first considering when a higher order PH -type distribution is just negative exponential. In Chapter 5, we consider the related question of minimal order representations for PH -type distributions, an issue which has attracted much interest in the literature. A discussion of other authors' ideas is given and these ideas are then inter-related to the work presented in Chapter 4 on the PH -type distributions. The MAP/M/1 queue is then considered in Chapter 6 from the perspective of whether having an exact level and phase independent stationary distribution of the geometric form [Formula - Not available: see pdf version of the abstract] implies that the MAP is Poisson. The answer is in the affirmative for this question, but the converse is not strictly true. Apart from showing the ubiquitous asymptotic form of level and phase independence exhibited by all stable MAP/M/1 queues, we prove that a very large class of stable queues, exhibits what we have termed shift-one level and phase independence. Stable MAP/M/1 queues exhibiting shift-one level and phase independence, are characterised by a stationary distribution of the following form: [Formula - Not Available: see pdf version of the abstract] In Chapter 7, a family of approximations is proposed for the output process of a stationary MAP/PH/1 queue. To check the viability of these approximations, they are used as input to another single server queue. Performance measures for the second server are obtained analytically in both the tandem and approximation cases, thus eliminating the need for simulation to compare results. Comparison of these approximations is also made against other approximation methods in the literature. In Chapter 8, we show that our approximations from Chapter 7 have the property of exactly matching the inter-departure time distribution. Our kth approximation also accurately captures the first k-1 lag-correlation coefficients of the stationary departure process. The proofs of this direct association between lag-correlation coefficients and the level of complexity k are given. / Thesis (Ph.D.)--School of Applied Mathematics, 1999.
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Capacitive pH-Sensors using pH sensitive polymer<em></em>Chinnam, Krishna Chytanya January 2009 (has links)
<p><p>This project aims in building a new experimental setup for capacitive measurements of a pH-Sensor. PAA-IOA (Poly Acrylic Acid co – Iso Octyl Acrylate) is the dielectric material over the in-plane interdigitated gold electrodes where PAA IOA acts as an H<sup>+</sup> ion sensing layer. The changes in the capacitance of the sensor when the sensor is dipped into different pH solutions will be quantized accordingly. The dipping setup is built in such a way that the electrodes (containing the polymer layer) can be easily dipped into different pH liquids and to eliminate any contact between the polymer and set-up (e.g. pressure effects on the sensor). From the setup it is visible that the gold electrodes are not subjected to any external force as in the case of the setup used previously. Three phases of experiments have been used in this project to get a clear view on the working principle of the polymer. The effect of pH is only considered in this project, as we already have the evidences for the salt sensitiveness of PAA IOA from the work done in the past. The influence of various pH on polymer is observed as capacitance measurements. Response time is more than 5 minutes for PAA IOA. ∆C decreases with frequency and frequency choice depends on application/electronics. The degree of other ions influence is not clear but they have a minor influence in the resistance.</p></p>
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Capacitive pH-Sensors using pH sensitive polymerChinnam, Krishna Chytanya January 2009 (has links)
This project aims in building a new experimental setup for capacitive measurements of a pH-Sensor. PAA-IOA (Poly Acrylic Acid co – Iso Octyl Acrylate) is the dielectric material over the in-plane interdigitated gold electrodes where PAA IOA acts as an H+ ion sensing layer. The changes in the capacitance of the sensor when the sensor is dipped into different pH solutions will be quantized accordingly. The dipping setup is built in such a way that the electrodes (containing the polymer layer) can be easily dipped into different pH liquids and to eliminate any contact between the polymer and set-up (e.g. pressure effects on the sensor). From the setup it is visible that the gold electrodes are not subjected to any external force as in the case of the setup used previously. Three phases of experiments have been used in this project to get a clear view on the working principle of the polymer. The effect of pH is only considered in this project, as we already have the evidences for the salt sensitiveness of PAA IOA from the work done in the past. The influence of various pH on polymer is observed as capacitance measurements. Response time is more than 5 minutes for PAA IOA. ∆C decreases with frequency and frequency choice depends on application/electronics. The degree of other ions influence is not clear but they have a minor influence in the resistance.
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Kartläggning av pH och COD vid pappersbruken Munskjö Paper AB och SCA Hygiene products AB / Mapping of pH and COD in paper mills of Munksjö Paper AB and SCA Hygiene Products ABPuskar, Aldijana January 2010 (has links)
<p>Pappersbruken har två pappersmaskiner, PM4 som tillverkar mjukpapper från returfiber och PM13 som tillverkar papper till transformatorer och kablar från oblekt barrsulfatmassa. Överskottsvattnet från PM4, PM13 och returfiberanläggningen samt dagvattnet leds vidare till den externa avloppsreningen. Då någon utav pappersbruken har driftsstop erhålls ojämna utfall främst för pH och COD.</p><p>Syftet med projektet är att kartlägga pH och COD förändringen i de enskilda delstegen i processerna PM 4, PM 13 samt den externa avloppsreningen.</p><p>Det genomfördes intensiv provtagning från tolv provtagningspunkter i trettiotvå dagar. Prover analyserades samma dag med avseende på pH, konduktivitet, alkalinitet, COD, suspenderade ämnen och glödrester. Dessutom utfördes fällningsförsök på inkommande processavloppsvatten med styrd dosering av järnsulfat, järnklorid och aluminiumsulfat. Det genomfördes även metodvalidering, kalciumbestämning, samt försök med sammanblandat avloppsvattenprov.</p><p>Resultat från mätningarna visar att processlinje PM 4 har generellt sätt högre pH-, konduktivitet-, alkalinitet - och COD värden och högre halt glödrester, men lägre halt suspenderade ämnen än PM 13. Det konstaterades att den största förändringen i de två processerna sker strax innan och efter pappersmaskinen. Efter pappersmaskinen, i det vattnet som leds vidare till den externa avloppsreningen, erhålls 70% COD reduktion och en pH ökning på 0,75 pH ekvivalenter för PM 13, respektive 30% COD reduktion och en pH sänkning på 1,27 pH ekvivalenter för PM 4. Totalt sätt, tyder resultat på att den största pH förändringen sker vid avloppsreningen, med 1,74 pH ekvivalenter. Från fällningsförsöken konstateras det att bästa pH- och lägsta COD- värden erhålls för fällningsmedlen, järnklorid och järnsulfat vid lägsta doseringsmängder, d.v.s. 97 g/m<sup>3</sup> respektive 101 g/m<sup>3</sup>, utan pH justering. Resultat från jämförelse mellan processavloppsvatten och sammanblandat avloppsvatten, där dagvattenpåverkan utesluts tyder på 0,01-0,86 högre pH-värden i dem sammanblandade avloppsvattenprover. Alltså finns det en antydan att dagvatten bidrar till pH sänkning i ingående processavloppsvatten. För att åtgärda problemen borde järnklorid utprövas i lägre doseringsmängder i kombination med minskad svavelsyretillsats.<strong> </strong>Eventuellt kan järnklorid bytas ut mot järnsulfat. Installera mätinstrument för mätning av pH och COD direkt på det ingående- och utgående vattenflödet i den externa avloppsreningen för att möjliggöra exakt dosering av fällningskemikalierna utifrån dessa värden.</p><p>Dagvattnet borde avskiljas från avloppsreningen och istället avledas till det kommunala avloppsnätet.</p> / <p>The paper mills have two paper machines, the PM 4, producing tissue from the RCF and the PM 13, producing paper for transformers and cables from the unbleached softwood craft pulp. Excess water from PM4, PM13 and RCF factory, together with the storm water, leads on to the external wastewater treatment. When any of the paper mills has downtime, unequal outcomes are obtained, primarily with respect to pH and COD.</p><p>The aim of the project is to identify the individual steps in the processes PM 4, PM 13 and wastewater treatment re to the pH and COD changes.</p><p>Intensive sampling was carried out from twelve sampling points during thirty-two days. These samples were analyzed on the same day re to the pH, conductivity, alkalinity, COD, suspended solids, and inorganic residue. In addition, precipitation tests were carried out on the incoming wastewater with controlled doses of the ferrous sulphate, ferric chloride and aluminium sulphate. In addition methodological validation, calcium determination, and experiments with the mixed wastewater samples were carried out.</p><p>The results show that the process line PM 4 has generally higher pH, conductivity, alkalinity, COD and concentration inorganic residues, but has a lower content of suspended solids than PM 13. But the biggest difference in the two processes takes place just before and after the paper machine. After the paper machine, the water that goes on to the external wastewater treatment, where a 70% COD reduction and a pH increase of 0,75 pH equivalents for PM 13, and 30% COD reduction and a pH decrease of 1,27 pH equivalents for the PM 4 are obtained. The results suggest that the greatest pH change occurs in wastewater treatment, with 22.06%. From precipitation experiments it was found that the best pH values and lowest COD values where obtained for precipitation chemicals, ferric chloride and ferrous sulphate at the lowest dose levels, i.e. 97 g/m<sup>3</sup> and 101 g/m<sup>3</sup>, without pH adjustment. Results from the correlation between wastewater- and mixed wastewater samples, which excludes impact of storm water, indicates that pH values are 0.01 to 0.86 pH equivalents higher in those mixed wastewater samples. Thus, there is a hint that the storm water contributes to pH reduction of the input wastewater.</p><p>To address these concerns ferric chloride should be tested at lower dose levels combined with reduced sulphuric acid addition. Eventually ferric chloride may be replaced by the iron sulphate. In addition, there should be measuring devices for pH and COD installed on the process wastewater and outgoing water, in the external wastewater treatment in order to allow for accurate dosing of chemicals precipitate from these values. Storm water should be separated from wastewater treatment and instead be diverted directly to the municipal sewage system.</p>
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Imagerie spectroscopique et spectroscopie localisée par RMN du proton in vivo.<br />Application à l'étude de la physiopathologie tumorale par cartographie des métabolites et du pH extracellulaire dans un modèle experimental de gliomes C6Provent, Peggy 13 December 2006 (has links) (PDF)
L'objectif de ce travail était d'optimiser les conditions ainsi que les techniques d'acquisition par spectroscopie et par imagerie spectroscopique par RMN du proton in vivo, chez le petit animal pour les appliquer à des études biologiques. Les conditions d'acquisitions ont été améliorées par la mise en place d'une technique de correction automatique des inhomogénéités de champ magnétique. Les séquences d'acquisition ont été optimisées par l'utilisation de la technique de suppression d'eau VAPOR et par l'utilisation de l'imagerie spectroscopique par encodage spiral à temps d'écho court. <br />Le pH extracellulaire (pHe) dans les tumeurs est plus acide que dans le tissu sain. Cette acidité semble être un facteur favorisant la prolifération. A l'aide d'une nouvelle molécule sonde, l'ISUCA, nous avons utilisé l'imagerie spectroscopique pour cartographier la distribution de pH extracellulaire dans les tumeurs et la comparer avec la distribution du lactate. Celles-ci ne sont pas corrélées spatialement, de plus à la suite d'une hyperglycémie, les quantités de lactate et de protons augmentent de manière globale mais avec une corrélation spatiale négative. Ces résultats suggèrent une redistribution des protons des sites de la glycolyse vers des pompes membranaires.<br />Le second projet biologique portait sur l'étude du rôle de l'ammonium dans la régulation de la glycolyse dans le cerveau. L'hyperammoniémie augmente la concentration de lactate cérébral: j'ai montré que cette augmentation peut être transitoire, ce qui est une condition incontournable pour un éventuel rôle physiologique de l'ammonium dans le couplage métabolique entre neurones et astrocytes.
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Ūkininkavimo įtaka šachtinių šulinių vandens kokybei / Farming influences research of the shallows water qualityZazaitė, Gitana 16 August 2007 (has links)
Magistro darbe yra tiriama Kauno rajone, Mitkūnų kaime esančių 5 šachtinių šulinių vandens užterštumas azoto junginiais ir organinėmis medžiagomis. Darbo objektas – šachtinių šulinių vandens kokybės parametrai: nitratai (NO3ˉ ), nitritai (NO2ˉ ), permanganatinė oksidacija (ChDSMn), pH. Darbo tikslas – įvertinti ūkininkavimo įtaką geriamo vandens kokybei ir ryšio tarp sodybos dirbtinių vandens telkinių ir šachtinių šulinių vandens kokybės nustatymas.. Darbo metodai – mokslinės literatūros analizė; cheminės vandens kokybės parametrų kiekybiniai analizės metodai; statistinė analizė, panaudojant EXCEL ir STATISTCA programinius paketus. Darbo rezultatai :atlikus tyrimus nustatyta, kad vanduo užterštas nitratais. Šachtinių šulinių vandens kokybės kitimui būdinga sezoninė tarša. / Subject of research – shallows water quality indicators: nitrate (NO3ֿ), nitrite (NO2ֿ), organic matter (ChDSMn), water pH. Aim of research – to evaluate farming influence of drinking water quality and contact between homestead pond and shallows water quality. Methodology – analysis of scientific literature; chemical water quality analizes methods; statistical analysis using EXCEL, STATISTICA programs. Results of research – the results of scientific research showed, that water is polluted with nitrate. The tendency of water quality variations during seasons was observed.
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A novel non-invasive optical method for quantitative visualization of pH and oxygen dynamics in soilsRudolph-Mohr, Nicole January 2013 (has links)
In soils and sediments there is a strong coupling between local biogeochemical processes and the distribution of water, electron acceptors, acids and nutrients. Both sides are closely related and affect each other from small scale to larger scales. Soil structures such as aggregates, roots, layers or macropores enhance the patchiness of these distributions. At the same time it is difficult to access the spatial distribution and temporal dynamics of these parameter. Noninvasive imaging techniques with high spatial and temporal resolution overcome these limitations. And new non-invasive techniques are needed to study the dynamic interaction of plant roots with the surrounding soil, but also the complex physical and chemical processes in structured soils. In this study we developed an efficient non-destructive in-situ method to determine biogeochemical parameters relevant to plant roots growing in soil. This is a quantitative fluorescence imaging method suitable for visualizing the spatial and temporal pH changes around roots. We adapted the fluorescence imaging set-up and coupled it with neutron radiography to study simultaneously root growth, oxygen depletion by respiration activity and root water uptake. The combined set up was subsequently applied to a structured soil system to map the patchy structure of oxic and anoxic zones induced by a chemical oxygen consumption reaction for spatially varying water
contents. Moreover, results from a similar fluorescence imaging technique for nitrate detection were complemented by a numerical modeling study where we used imaging data, aiming to simulate biodegradation under anaerobic, nitrate reducing conditions. / In Böden und Sedimenten sind biogeochemische Prozesse und die Verteilung von Größen wie Wasser, Elektronenakzeptoren, Säuregehalte und Nährstoffe in enger Weise miteinander gekoppelt. Diese wechselseitige Beeinflussung ist skalenübergreifend und reicht von sehr kleinen bis zu größeren Skalen. Die in realen Böden vorhandene Struktur z. Bsp. Aggregate, Pflanzenwurzeln, Schichten und Makroporen bedingen eine starke räumlich Heterogenität und zeitliche Dynamik dieser Größen. Gleichzeitig sind Verteilung und Dynamik sehr schwer zu beobachten, zumindest ohne ihre gleichzeitige Störung. Bildgebende Verfahren bieten eine sehr gute räumliche und zeitliche Auflösung und ermöglichen die Darstellung dieser Größen. Um die dynamische Wechselwirkung zwischen Pflanzenwurzeln und Boden, aber auch die komplexen physikalisch – chemischen Prozesse in Böden zu verstehen, sind neue bildgebende Verfahren notwendig. Ziel dieser Arbeit war es, eine neue nicht-invasive Methode zu entwickeln, die es ermöglicht biogeochemische Parameter in der Wurzelzone zu visualisieren. Innerhalb dieser Studie wurde ein quantitatives bildgebendes Verfahren entwickelt, dass die räumlichen und zeitlichen Dynamiken des pH Wertes in der Rhizosphäre erfasst. Diese auf Fluoreszenzemissionen basierende Methode wurde ebenso für Sauerstoffdetektion entwickelt und mit Neutronen Radiographie kombiniert um gleichzeitig Aussagen über Wurzelwachstum, Sauerstoffzehrung durch Wurzelatmung und Wurzelwasseraufnahme treffen zu können. Die kombinierte bildgebende Methode wurde dann in einem künstlichen Boden genutzt um Nischen und Übergangsbereiche von Sauerstoff bei variierenden Wassergehalten zu charakterisieren. Das große Potential von bildgebenden Verfahren zeigt sich bei Modellierungsstudien. In dieser Studie wurden Bilddaten als Eingabeparameter für die Simulierung von denitrifizierendem biologischem Schadstoffabbau genutzt.
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Soil sampling methods for pH tests in soils of different genesis and relief and geostatistical analysis of data / PH ėminių paėmimo metodai ir duomenų geostatistinė analizė skirtingo reljefo bei genezės dirvožemiuoseŠumskis, Donatas 07 December 2011 (has links)
Tasks: 1. To determine a soil sampling method most suitable for pH tests in soils on flat, rolling and hilly relief using regular grid sampling, soil database (Dirv_DB10LT) and soil agrochemical properties database (DirvAgroch_DB10LT). 2. To investigate the suitability of geostatistical methods for spatial distribution of pH data using different soil sampling methods. 3. To determine an impact of different soil sampling methods on spatial distribution of areas to be limed and on the needed amount of lime. Propositions to be defended: 1. Soil sampling plots for detailed pH tests should be shaped using soil database (Dirv_DB10LT) and soil agrochemical properties database (DirvAgroch_DB10LT); in case of high variability of pH values soil sampling plots should be smaller and in case of lower variability of pH values – larger. 2. Interpolation of pH data using IDW, Simple Kriging and Simple Cokriging methods results in decreased share of determined areas of conditionally acid soils when compared to that obtained using not interpolated pH data. 3. The needed amount of lime depends on soil sampling method. Larger needed amount of lime is calculated when soil samples are collected using databases (Dirv_DB10LT) and (DirvAgroch_DB10LT). / Uždaviniai: 1. Nustatyti dirvoţemio pH tyrimams tinkamiausią ėminių paėmimo metodą lyguminio, banguoto ir kalvoto reljefo plotuose, taikant taisyklingą tinklelį, dirvoţemio (Dirv_DB10LT) ir agrocheminių savybių (DirvAgroch_DB10LT) duomenų bazes. 2. Ištirti geostatistinių metodų tinkamumą pH duomenų erdviniam pasiskirstymui, taikant skirtingus ėminių paėmimo metodus. 3. Nustatyti ėminių paėmimo metodų įtaką kalkintinų plotų erdviniam pasiskirstymui ir kalkių reikmei. 32 Ginami disertacijos teiginiai: 1. Išsamiam dirvoţemio pH tyrimui ėminio paėmimo laukelius tikslinga formuoti naudojant dirvoţemių (Dirv_DB10LT) ir agrocheminių savybių (DirvAgroch_DB10LT) duomenų bazes, esant dideliam pH įvairavimui, dirvoţemio ėminius reikėtų imti tankiau, kai įvairavimas maţesnis – rečiau. 2. Dirvoţemio pH duomenis interpoliuojant IDW, paprastojo krigingo ir paprastojo kokrigingo metodais, sąlygiškai rūgščių plotų gaunama maţiau, palyginti su neinterpoliuotais. 3. Priklausomai nuo dirvoţemio ėminio paėmimo metodo, apskaičiuojama skirtinga kalkinių trąšų reikmė, ji didesnė plotuose, kuriuose dirvoţemio ėminiai imami naudojantis (Dirv_DB10LT) ir (DirvAgroch_DB10LT) duomenų bazėmis.
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