The today quarry planning at Klinthagen is rough, which provides an opportunity to introduce new exciting methods to improve the quarry gain and efficiency. Nordkalk AB, active at Klinthagen, wishes to start a new quarry at a nearby location. To exploit future quarries in an efficient manner and ensure production quality, multivariate statistics may help gather important information. In this thesis the possibilities of the multivariate statistical approaches of Principal Component Analysis (PCA) and Partial Least Squares (PLS) regression were evaluated on the Klinthagen bore data. PCA data were spatially interpolated by Kriging, which also was evaluated and compared to IDW interpolation. Principal component analysis supplied an overview of the variables relations, but also visualised the problems involved when linking geophysical data to geochemical data and the inaccuracy introduced by lacking data quality. The PLS regression further emphasised the geochemical-geophysical problems, but also showed good precision when applied to strictly geochemical data. Spatial interpolation by Kriging did not result in significantly better approximations than the less complex control interpolation by IDW. In order to improve the information content of the data when modelled by PCA, a more discrete sampling method would be advisable. The data quality may cause trouble, though with sample technique of today it was considered to be of less consequence. Faced with a single geophysical component to be predicted from chemical variables further geophysical data need to complement existing data to achieve satisfying PLS models. The stratified rock composure caused trouble when spatially interpolated. Further investigations should be performed to develop more suitable interpolation techniques.

The primary objective was to predict the relative storage capacity of carbonate rocks relevant for carbon dioxide sequestration. To achieve this, a detailed pore scale characterization of model carbonate rocks, Indiana Limestone and Pink Dolomite, was conducted utilizing micro-computed tomography (microCT) data using pore network modeling and invasion percolation simulations. For the first time in literature, Pink Dolomite’s pore space characteristics were analyzed. A secondary objective was to compare thresholding techniques as applied to carbonates which exhibit dual porosity (porosity at multiple length scales). The analysis showed the sensitivity of existing methods to the thresholding technique, imaging method and material. Overall, the contributions of this work provide an assessment of two carbonates relevant for carbon capture and storage at the pore scale; and a preliminary assessment into thresholding dual porosity carbonates.

The primary objective was to predict the relative storage capacity of carbonate rocks relevant for carbon dioxide sequestration. To achieve this, a detailed pore scale characterization of model carbonate rocks, Indiana Limestone and Pink Dolomite, was conducted utilizing micro-computed tomography (microCT) data using pore network modeling and invasion percolation simulations. For the first time in literature, Pink Dolomite’s pore space characteristics were analyzed. A secondary objective was to compare thresholding techniques as applied to carbonates which exhibit dual porosity (porosity at multiple length scales). The analysis showed the sensitivity of existing methods to the thresholding technique, imaging method and material. Overall, the contributions of this work provide an assessment of two carbonates relevant for carbon capture and storage at the pore scale; and a preliminary assessment into thresholding dual porosity carbonates.

Traditionally New Zealand ecological research has focused on nature outside of cities, however, as with global trends, there is now more interest being given to the ecological functioning of cities and the potential they may hold for protecting native biodiversity. Traditionally, efforts to maintain biodiversity in urban areas have been restricted to remnants of native vegetation and restoration activities. Little attention has been given to how native biodiversity could be woven into the urban fabric in an ecologically meaningful way. One option, that is receiving much attention overseas, is to recruit underutilised urban spaces such as wasteland. A subset of urban wasteland, abandoned industrial areas usually awaiting development and other areas such as the railway buffer, are referred to here as greyfield. These are ephemeral sites that may sit between uses for as little as a few months to many years. Overseas, particularly in European countries, these have been recognised as important habitat for both native and introduced plant species. In New Zealand cities these support primarily introduced plants and their contribution to native biodiversity has been unknown. This thesis took an interdisciplinary approach to the question of whether urban greyfields might have potential value as biodiversity protection and conservation opportunity. Ecological methods were combined with an assessment of the planning framework to answer this question. iii Greyfields in Christchurch, New Zealand were surveyed to determine their current contribution to native biodiversity and whether they may act as urban analogues of natural habitats. Overseas research has shown that urban features such as pavements, walls and rooftops offer habitats analogous to cliffs and rocky habitats. Cities are therefore increasing the habitat exploitable by species whose natural habitats are geographically restricted. The Christchurch greyfields were assessed for their potential to act as analogues of four habitat types that have been categorised as historically rare in New Zealand: braided riverbeds, shingle beaches, rock outcrops and limestone outcrops. The findings suggest that urban greyfields, if managed appropriately, have the potential to support a wider range of native species Planning documents and biodiversity strategies written for Christchurch were assessed to see how well they facilitated non-traditional biodiversity enhancement initiatives, specifically the greyfield network for native biodiversity. A major finding here was a lack of information on how to enhance biodiversity where little of the natural features of the landscape were left and that this was creating a barrier to adopting more integrative approaches to enhancing native biodiversity. Finally, a plan to create a greyfield network for native biodiversity is proposed and suggestions are made as to minor changes to the planning framework that would more easily facilitate the uptake of novel biodiversity enhancement initiatives in the City.

Η κρυστάλλωση και η διάλυση αλάτων αποτελούν σημαντικές διεργασίες οι οποίες συνεισφέρουν στην φθορά των μνημείων της πολιτιστικής μας κληρονομιάς, τα οποία έχουν κατά κύριο λόγο κατασκευασθεί από δομικά υλικά όπως ο ασβεστόλιθoς και το μάρμαρο. Η κρυστάλλωση ευδιάλυτων αλάτων (π.χ. θειϊκό νάτριο, θειϊκό μαγνήσιο, χλωριούχο νάτριο) σε πορώδη υλικά έχει καταστροφικές επιπτώσεις τόσο στις ιστορικές όσο και στις σύγχρονες κατασκευές από σκυρόδεμα. Το πιο κατεστρεπτικό άλας για την ακεραιότητα των κατασκευών έχει αποδειχθεί, ότι είναι το θειίκό νάτριο. Η κατανόηση του μηχανισμού κρυστάλλωσης του άλατος αυτού είναι απαραίτητη προϋπόθεση για τον περιορισμό ή τον έλεγχο του σχηματισμού του σε ατμοσφαιρικές συνθήκες. Για τον σκοπό αυτό, έγινε συστηματική μελέτη της κρυσταλλικής ανάπτυξης του δεκαένυδρου θειϊκού νατρίου (Μιραμπιλίτης) σε υπέρκορα διαλύματά του. Αναπτύχθηκε μεθοδολογία βασισμένη στον εξώθερμο χαρακτήρα της κρυσταλλικής ανάπτυξης του μιραμπιλίτη. Η πειραματική μελέτη περιορίσθηκε στην ετερογενή κρυσταλλική ανάπτυξη τόσο σε φύτρα Μιραμπιλίτη, όσο και σε ξένα υποστρώματα. Τα υποστρώματα τα οποία μελετήθηκαν περιλάμβαναν ασβεστόλιθο από την Γρανάδα (ασβεστιτικός κυρίως) καθώς και ψαμμόλιθο (Πράγα, Τσεχίας) πυριτικής κατά κύριο λόγο σύστασης. Η μελέτη της κινητικής της κρυσταλλικής ανάπτυξης του Μιραμπιλίτη, έδειξε ότι το καθορίζον την ταχύτητα στάδιο είναι η διάχυση των δομικών μονάδων στην επιφάνεια των κρυσταλλικών φύτρων του Μιραμπιλίτη. Το συμπέρασμα αυτό οδήγησε στην δοκιμή οργανοφωσφορικών ενώσεων, ως προς την επίδρασή τους στην κινητική της κρυσταλλικής ανάπτυξης του μιραμπιλίτη. Οι ενώσεις αυτές ιονίζονται και αλληλεπιδρούν αποτελεσματικά με την κρυσταλλική επιφάνεια δηλητηριάζοντας τα ενεργά κέντρα κρυστάλλωσης. Ο βαθμός ιονισμού βρέθηκε ότι είναι καθοριστικός για την ανασταλτική τους δράση. Πειράματα ταχείας καταβύθισης ευδιάλυτων αλάτων ηλεκτρολυτών σε ασβεστολιθικά και ψαμμιτικά δοκίμια τα οποία έγιναν τόσο με εμβάπτιση, όσο και με έκθεση σε θάλαμο αλατονέφωσης επιβεβαίωσαν τα αποτελέσματα της μελέτης της κινητικής της κρυστάλλωσης του Μιραμπιλίτη και της σχετικής αποτελεσματικότητος των αναστολέων που χρησιμοποιήθηκαν. Πλην της κρυσταλλικής ανάπτυξης ευδιάλυτων αλάτων, σημαντική συνεισφορά στην αποδόμηση των δομικών υλικών παίζει και η διάλυση του ανθρακικού ασβεστίου, το οποίο και αποτελεί τη βασική συστατική τους ένωση. Για τη μελέτη της διεργασίας της κρυσταλλικής ανάπτυξης και διάλυσης του ανθρακικού ασβεστίου τόσο απουσία όσο και παρουσία ανιόντων όπως τα θειϊκά και τα ανιόντα φθορίου χρησιμοποιήθηκε η μικροσκοπία ατομικής δύναμης,η οποία έδωσε την δυνατότητα in situ μέτρησης του ρυθμού κρυσταλλικής ανάπτυξης και διάλυσης σε συνθήκες σταθερού κορεσμού. Η παρουσία θειϊκών ανιόντων έδειξε ότι η κρυσταλλική ανάπτυξη του ανθρακικού ασβεστίου αναστέλλεται ενώ η παρουσία φθορίου επιταχύνει τη διάλυση. Τα αποτελέσματα των μετρήσεων της κινητικής των διεργασιών έδειξαν ότι οι επιμολύνσεις στα υπέρκορα διαλύματα δρούν στην κινητική λόγω προσρόφησης και δέσμευσης των ενεργών κέντρων κρυσταλλικής ανάπτυξης διάλυσης. / The research made in the present PhD Thesis entitled “Crystallization and dissolution study of electrolyte salts”. The objective of the dissertation concerned both crystallization and dissolution processes of soluble sodium sulfate and insoluble calcium carbonate electrolyte salts approached by different experimental aspects but directly connected to environmental and scientific issues. Salt crystallization is an important cause for the weathering and damage of historical and cultural heritage artifacts and ornamental stones. Soluble salts (i.e. sodium sulfate, magnesium sulfate, sodium chloride) have also a damaging and fateful impact on civil engineering structures of roads and building foundations. Most damaging salt for such built frameworks is proven to be sodium sulfate salt. Only when we have a better understanding of sodium sulfate crystallization in an unconstrained fluid medium can we progress to a study of sodium sulfate crystallization in porous building materials. At the beginning of this study batch crystallization experiments of sodium sulfate salt were conducted. Additionally potential organic inhibitors (i.e. organophosphonate, polyacrylates) were tested in the same batch experimental system. Popular and applicable limestone building material is of uniform composition consisting mainly calcium (calcitic material). Granada’s calcarenite has been selected as one of the target material to study. This natural stone is representative of the building material utilized in construction material monuments and susceptible to salt crystallization. In situ AFM experiments of both calcite crystal growth and dissolution were performed in the presence of different electrolyte solutions (i.e. sodium sulfate and sodium fluoride). Nanoscale phenomena during the growth of solid solutions on calcite surfaces were performed in the presence of sodium sulfate electrolyte solutions. Further molecular-scale surface processes during both growth and dissolution of calcite in the presence of sodium fluoride electrolyte solutions were carried out. In all cases significant kinetic data and reaction mechanisms were extracted. Accelerated degradation of Granada’s limestone and Czech sandstone experiments were executed. Tested materials were exposed and impregnated in concentrated solutions of soluble salts (i.e. sodium sulfate, magnesium sulfate and sodium chloride). Immersed limestone type material showed susceptibility to sodium sulfate and sandstone type material to sodium chloride salt solution. Different pre-treatments of limestone specimens with organophosphonate compounds resulted in limiting material damage from sodium sulfate influence. The use of such organic compounds may direct towards a potential implication of conserving building frameworks. Finally suspended limestone rods were subjected to sodium sulfate spray chamber. Pre-treatment of limestone rods with organophosphonate compounds were completed. Again applications of organophosphonate compounds to exposure of limestone material in salt spray chamber may work towards a case of preventing porous material from salt damage and protect building stones.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-09T16:57:24Z No. of bitstreams: 1 ROSA MARIA GONÇALVES COÊLHO - DISSERTAÇÃO PPGECA 1995..pdf: 23915263 bytes, checksum: 4e9195023b290e36631b4c43b7d4cbea (MD5) / Made available in DSpace on 2018-11-09T16:57:24Z (GMT). No. of bitstreams: 1 ROSA MARIA GONÇALVES COÊLHO - DISSERTAÇÃO PPGECA 1995..pdf: 23915263 bytes, checksum: 4e9195023b290e36631b4c43b7d4cbea (MD5) Previous issue date: 1995-12-18 / CNPq / Esta dissertação apresenta os resultados de uma pesquisa desenvolvida com o objetivo de se utilizar o agregado graúdo não convencional calcário, de formações calcítica e dolomítica, como agregado alternativo em substituição ao agregado convencionalmente usado na fabricação dos concretos betuminosos usinados à quente, como forma de redução de custos de obras rodoviárias, em regiões onde as rochas calcárias são predominantes. Para que pudessem ser comprovadas as características que mostram a resistência da mistura betuminosa, foi utilizado o Ensaio Marshall. Foram feitos ensaios físicos e mecânicos de forma a comprovar suas características na pavimentação. São apresentados alguns resultados de serviços executados na pavimentação da cidade de Mossoró-RN, com resultados satisfatórios de uso nas diferentes camadas do pavimento. Os resultados obtidos nesta pesquisa permitiram concluir que devido a resistência satisfatória e propriedades similares as da brita granítica além de menores custos de extração e britagem, o agregado calcário pode substituí-la com muita propriedade, quando empregado no uso de concreto betuminoso usinado à quente como revestimento em rodovias, reduzindo-se o custo final da obra. / This thesis presents the results of an investigation carried out to study the performance of a non conventional aggregate, calcareous aggregate of the dolomitic and calcitic formation, in substitution to the dolomitic and calcitic aggregate. used to fabricate hot-mix bituminous concrete. The predominant characteristics of the bituminous mixtures were evaluated using the traditional Marshall test. In order to determine the quality of the mixture, physic and mechanic tests were applied. The results obtained in this investigation in regard to existing pavement, named airport of Mossoró-RN city, constructed with calcareous aggregate in the bituminous mixtures, revealed that the altermative mixture made with calcareous aggregate, is a valid one. Also, the results from laboratory tests, showed that the strength property of the bituminous mixture made with the normal granitic aggregate. Therefore, based on these results, it can concluded that the calcareous aggregate is an alternative aggregate that can be used to fabricate bituminous mixtures, in replacement of the conventional granitic aggregate.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The lime application decrease soil acidity and increase the exchangeable calcium (Ca) and magnesium (Mg) level. calcitic and dolomitic limes cannot present the same efficiency in soil acidity correction and since it can enlarge or narrow the Ca:Mg soil relationship, it also may cause nutritional problems to the plants or even to harm their development. Four experiments were carried out: one in a greenhouse and three in field conditions. The greenhouse experiment aimed to quantify the calcium and magnesium supply to the soybean roots cultivated in soil with Mg growing saturations in CEC pH 7. A no-liming Oxisoil was used; it was collected right on the 0-20 cm layer, dry, grind and sieved through 2 mm. Then CaCO3 or the CaCO3+MgCO3 mixture was applied aiming at elevating the water pH up to 6, making possible Mg growing saturations in CEC pH 7. The soil was conditioned in pots and, after incubation, cultivated with soybean for a period of 80 days. During the experiment, dry matter production evaluations, content and accumulation of calcium and also magnesium on tissue were carried out as well as the supply of those to the roots. The three field experiments were accomplished with two main objectives: a) to evaluate the resulting alterations of the calcitic and dolomitic limestone proportions application in the soils exchangeable level of calcium and magnesium and also to verify their effects in plants nutrition; and b) to evaluate the efficiency of calcitic and dolomitic limestone with superficial and incorporate application in soil acidity correction and in the productivity of crops in no-tillage. These experiments were carried in october 2004, in Rio Grande do Sul state different physiographic areas through no-tillage and cultivated with annual crops. The treatments consisted in an enough dose of calcitic and dolomitic limestone application proportions to elevate the pH in water up to 6, applied in the surface or incorporated. The production of black oats dry matter and soybean, wheat, canola grains yeild, and content of Ca and Mg in the vegetable tissue of these cultures were evaluated. After 42 months from the treatment application, soil samples were collected in the layers of 0-5; 5-10; 10-15; 15-20 and 0-10 cm and then the exchangeable level of Ca, Mg and Al, pH in water and saturation for bases were determined. The results show that the Ca and Mg plants content alterations are due to the magnitude of the supply of those to the roots more than to the Ca:Mg ratio. The limestone considerably alter the level of Ca and exchangeable Mg and also the Ca:Mg ratio of the soil, what does not provoke nutritional problems to the cultures as long as the soil tenors are enough, the interaction among both cations in the plant absorption is of low intensity or it does even exist. The calcitic and dolomitic limestone present the same agronomic efficiency in the acidity correction and the crops productivity is not affected by the type of applied limestone. / A aplicação de calcário corrige a acidez do solo e eleva os teores de cálcio (Ca) e magnésio (Mg) trocáveis. Os calcários calcítico e dolomítico podem não apresentar a mesma eficiência na correção da acidez do solo e, por aumentar ou diminuir a relação Ca:Mg do solo, causar problemas nutricionais às plantas e prejudicar o seu desenvolvimento. Foram conduzidos quatro experimentos: um em casa de vegetação e três em condições de campo. O experimento de casa de vegetação teve como objetivo quantificar o suprimento de cálcio e magnésio às raízes de soja cultivadas em solo com saturações crescentes de Mg na CTC pH 7. Utilizou-se um solo Latossolo Vermelho distrófico típico sem histórico de calagem, que foi coletado na camada 0-20 cm, seco, moído e passado em peneira de 2 mm. Em seguida, aplicou-se CaCO3 ou a mistura de CaCO3+MgCO3 em quantidade suficiente para elevar o pH em água até 6 e capaz de criar saturações crescentes de Mg na CTC pH 7. O solo foi acondicionado em vasos e, após incubação, cultivado com soja por um período de 80 dias. Durante o experimento, foram realizadas avaliações da produção de matéria seca, teores e acumulo de cálcio e magnésio nos tecidos e o suprimento destes às raízes. Os três experimentos de campo foram realizados com dois objetivos: a) avaliar as alterações resultantes da aplicação de proporções de calcários calcítico e dolomítico nos teores trocáveis de cálcio e magnésio de solos e verificar seus efeitos na nutrição de plantas; e b) avaliar a eficiência de calcários calcítico e dolomítico com aplicação superficial e incorporada na correção da acidez de solos e na produtividade de culturas em sistema de plantio direto. Estes experimentos foram instalados em outubro de 2004, em diferentes regiões fisiográficas do Estado do Rio Grande do Sul, conduzidos sob Sistema Plantio Direto e cultivados com culturas anuais. Os tratamentos consistiram da aplicação proporções de calcários calcítico e dolomítico em dose suficiente para elevar o pH em água a 6, aplicados em superfície ou incorporados por lavração e gradagem. Foram avaliadas a produção de matéria seca de aveia preta, rendimento de grãos de soja, trigo e canola e teores de Ca e Mg no tecido vegetal destas culturas. Aos 42 meses da aplicação dos tratamentos foram coletadas amostras de solo nas camadas de 0-5; 5-10; 10-15; 15-20 e 0-10 cm e determinados os teores trocáveis de Ca, Mg e Al, pH em água e saturação por bases. Os resultados mostram que a alteração dos teores de Ca e Mg das plantas está mais ligada à magnitude do suprimento destes às raízes do que à relação Ca:Mg. Os calcários alteram consideravelmente os teores de Ca e Mg trocáveis e a relação Ca:Mg do solo, o que não provoca problemas nutricionais às culturas, pois quando os teores do solo são suficientes, a interação entre estes dois cátions na absorção pela planta é de baixa intensidade ou não existe. Os calcários calcítico e dolomítico apresentam a mesma eficiência agronômica na correção da acidez e a produtividade das culturas não é afetada pelo tipo de calcário aplicado.

Two-phase flow in porous media is an important subsurface process that has significant impacts on the global economy and environments. To study two-phase system in porous media, capillary pressure (Pc ), relative permeability (Kr), bulk electrical conductivity (σb) and bulk relative permittivity (εb) are often employed as characterization parameters. Interestingly, all of these parameters are functions of water saturation (S). However, the non-uniqueness in the Pc -S, Kr-S,σb-S and εb-S relationships pose considerable challenges in employing them for effective monitoring and control of the two-phase flow processes. In this work, laboratory scale experiments and numerical simulations were conducted to investigate the factors and conditions contributing to the non-uniqueness in the above relationships for silicone oil-water and supercritical CO2-water flow in porous media, with a special emphasis on geological carbon sequestration. Specifically, the dynamic capillary pressure effect, which indicates the dependence of the Pc - S relationship on the rate of change of saturation (αS/αt) during two-phase flow in porous media was investigated. Using a silicone oil-water system, the dynamic capillary pressure effect was quantified in term of the parameter named the dynamic coefficient, τ , and it was found to be dependent on the domain scale and the viscosity ratio of the two fluids. It was found that τ increases with the domain scale and the viscosity ratio. It is inversely affected by αS αt , which is related to the degree of resistance to the fluid motion, namely, viscosity. In almost all cases, τ was found to decrease monotonically with an increase in water saturation, S. An order increase in magnitude of τ was observed as the domain scale increases from 4cm scale to 8cm in height. A similar order of increase in τ was observed in the 12cm high domain scale. There is an order increase in the value of τ for the silicone oilwater system as the viscosity ratio increases from 200 to 500. For the supercritical CO2 (scCO2) and water system in porous media, the experiments and numerical simulations showed that τ increases with rising system temperature and decreasing porous media permeability. Dimensionless analysis of the silicone oil-water experimental results showed that by constructing non-dimensional groups of quantities expressing a relationship among different variables on which τ depends, it is possible to summarise the experimental results and determine their functional relationship. A generalised scaling relationship for τ was derived from the dimensionless analysis which was then validated against independent literature data. The exercise showed that the τ-S relationship obtained from the literature and the ii scaling relationship match reasonably well. This work also demonstrated the applicability of an artificial neural network (ANN) as an alternative computational platform for the prediction of the domain scale dependence of τ . The dependence of the Kr-S relationship on αS/αt was also investigated. The results showed that the Kr-S curve under dynamic flow condition is different from that under the quasi-static condition. Kr for water (Krw) increases with increasing water saturation and decreases with the increase in viscosity ratio while Kr for silicone oil (Krnw) increases with decreasing water saturation as well as with the increase in viscosity ratio. Also, Krw decreases while Krnw increases with the increasing boundary pressure. However, the εb-S and σb-S relationships were found to be independent of αS/αt for the scCO2-water system in carbonate and silicate porous media. Nevertheless, the εb and σb values decrease as the water saturation decreases in the two porous media samples. While εb decreases with increase in temperature in silica sand, the trend in the limestone showed a slight increase with temperature, especially at high water saturation. Also, the εb-S relationship is shown to be affected by pressure in silica sand increasing with the pressure of the domain. On the contrary, the σb-S relationship increases as the temperature increases with more significance at higher water saturation in the silica sand sample. This work further demonstrated the application of a membrane in the monitoring of the CO2 in geological sites used for carbon sequestration. Commercial silicone rubber coupled with a pressure transducer showed potential in the detection of CO2 leakage from geological sites. The response of the device in terms of the mass of permeated gas, permeability and gas flux were investigated for both CO2 and N2. In addition, the monitoring of potable water contamination in a shallow aquifer by the migrating or leaking of CO2 is demonstrated with the combination of the pH analysis, geoelectrical measurement techniques and the membrane-sensor system. Overall, the work in this PhD research demonstrated robust applications of two-phase systems'characterization parameters under different scenarios in the porous media. Implications of the findings in this work to the monitoring and control of two-phase systems in porous media are expatiated.

Made available in DSpace on 2015-03-26T13:39:47Z (GMT). No. of bitstreams: 1 texto completo.pdf: 739809 bytes, checksum: 69524346956f11b5bb2a849577857347 (MD5) Previous issue date: 2012-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The competitive ability of crops and weeds is related to the efficient use of environmental resources. However, it may also be related to the associations of these species with soil microbiota and the ability to change it to minimize interference. The objective of this study was to evaluate the effects of the interference of five weeds in dry matter accumulation of corn plants and in the relative content of nutrients, as well as evaluate the biomass and microbial activity associated with weeds and corn in monoculture and in competition, in soils with diferent fertility managements. The experiment was conducted in a protected environment, considering four soil fertility managements (with calcium and magnesium silicate and fertilization; with limestone and fertilization; without correction of acidity, but with fertilization; without correction of acidity and without fertilization) and five arrangements competition between Zea mays and the weeds Brachiaria brizantha, Ipomoea grandifolia, Conyza canadensis, Bidens pilosa and Hyptis suaveolens, addition of species in monoculture and soils without plants. The coexistence of corn with weeds caused average reductions of 43.9%, 39.8% and 41.9% in dry matter of shoot, root and total culture, respectively. Under interference of B. brizantha, the corn had reductions exceeding 50% in the content of all macronutrients, being this weed the most damaging to the culture. Additionally, B. brizantha and B. pilosa in competition with corn stood out among the other weeds and has high ability to extract and use macronutrients in the four soil conditions. There was a tendency of reduction of microbial biomass carbon (MBC) in soils that receive were not correction acidity. B. pilosa and the arrangement formed by Z. mays and B. brizantha, showed high values of MBC, regardless of soil management. Low biological activity was observed in soil without acidity correction and without fertilization. In soil with calcium and magnesium silicate and maize plants in monoculture, the metabolic quotient (qCO2) was higher than the value observed with the weeds in monoculture and in competition arrangements, suggesting greater susceptibility of this system for carbon losses. Z. mays in competition with H. suaveolens was the arrangement that had greater preservation of organic matter (<qCO2) in the four soils. The weeds showed different competitive abilities causing reductions in the dry matter and nutrients accumulation in the corn plants, and showed distinct potential for nutrient cycling, depending on soil condition. Calcium and magnesium silicate and limestone did not differ in the weed interference on the dry biomass of corn plants, being the influence of these sources variable on nutrient accumulation by plants in monoculture or under interference. The microbial biomass and activity were altered by plant species, interference and managements of soil fertility. The manipulation of soil microorganisms may be a strategy used by corn and, or the weeds to minimize the competition in a given soil. / A habilidade competitiva das culturas e das plantas daninhas está relacionada à utilização eficiente dos recursos do meio na qual se encontram. No entanto, pode também estar relacionada com as associações dessas espécies com a microbiota do solo e a capacidade de alterá-la para minimizar a interferência. Objetivou-se com este trabalho avaliar os efeitos da interferência de cinco plantas daninhas no acúmulo de matéria seca e no conteúdo relativo de macronutrientes de plantas de milho, bem como a biomassa e a atividade microbiana associada às plantas daninhas e de milho em monocultivo e em competição, em solos com diferentes manejos de fertilidade. O experimento foi realizado em casa de vegetação, considerando-se como primeiro fator quatro manejos de fertilidade do solo (com silicato de cálcio e magnésio e adubação; com calcário e adubação; sem correção de acidez, mas com adubação; sem correção de acidez e sem adubação) e como segundo fator cinco arranjos de competição entre Zea mays e as plantas daninhas Brachiaria brizantha, Ipomoea grandifolia, Conyza canadensis, Hyptis suaveolens e Bidens pilosa, acrescido das seis espécies em monocultivo e de solo sem cultivo. A convivência do milho com plantas daninhas provocou reduções médias de 43,9%, 39,8% e 41,9% na massa da matéria seca da parte aérea, do sistema radicular e total da cultura, respectivamente. Sob interferência de B. brizantha, o milho apresentou reduções superiores a 50% no conteúdo de todos os macronutrientes, sendo esta a planta daninha mais danosa a cultura. Adicionalmente, B. brizantha e B. pilosa em competição com o milho se destacaram entre as demais plantas daninhas, apresentando elevada habilidade de extração e utilização de macronutrientes nas quatro condições de solo. Observou-se tendência de redução do carbono da biomassa microbina (CBM) nos solos que não tiveram correção de acidez. B. pilosa e o arranjo formado por Z. mays e B. brinzantha, independente do solo, apresentaram elevados valores de CBM. Baixa atividade biológica foi verificada no solo sem correção de acidez e sem adubação. No solo corrigido com silicato de cálcio e magnésio e cultivado com milho livre de interferência, o quociente metabólico (qCO2) foi maior do que com as plantas daninhas em monocultivo e arranjos de competição, sugerindo maior suscetibilidade desse sistema a perdas de carbono. Z. mays em competição com H. suaveolens mostrou ser o sistema misto mais conservativo da matéria orgânica (<qCO2) nos quatro manejos de fertilidade do solo. As plantas daninhas apresentaram não só habilidades competitivas distintas, provocando reduções consideráveis no acúmulo de matéria seca e nutrientes das plantas de milho, como também potencial diferenciado para ciclagem dos nutrientes estudados, a depender da condição de solo. Silicato de cálcio e magnésio e calcário não diferiram quanto à interferência das plantas daninhas sobre o acúmulo de biomassa seca das plantas de milho, sendo variável a influência dessas fontes sobre o acúmulo de nutrientes pelas plantas em monocultivo ou sob interferência. A biomassa e atividade microbiana foram alteradas pelas espécies de plantas, pela convivência e pelos manejos de fertilidade do solo, e a manipulação dos microrganismos do solo pode ser uma estratégia utilizada pela cultura do milho e, ou pelas plantas daninhas para minimizar a competição em determinado ambiente.

O objetivo desse trabalho é identificar o comportamento da areia de britagem de rocha calcária na argamassa de revestimento Foram propostas cinco composições de traço, a primeira com 100% areia natural, que será usado como traço de referência, a segunda composição com 80% areia natural, e 20% areia de britagem de rocha calcária, o terceiro com 60% areia natural e 40% areia de britagem de rocha calcária, o quarto com 40% areia natural e 60% areia de britagem de rocha calcária, e o quinto com 20% areia natural e 80% areia de britagem de rocha calcária. Os traços das argamassas foram compostos com cimento, areia, água e aditivo, sem a presença da cal, e estas foram ensaiadas no estado fresco e endurecido e apresentaram os seguintes resultados: Os traços compostos com a areia de britagem de rocha calcária apresentaram melhor desempenho que o traço de referência, composto apenas com areia natural. O traço com 60% de areia natural e 40% de areia de britagem de rocha calcária apresentou melhor desempenho em 70% dos ensaios realizados, tendo apresentado uma curva granulométrica dentro da zona ótima superior e inferior exigido pela norma. A relevância desse estudo se deve ao fato de que, a areia de britagem é um resíduo que gera um importante passivo ambiental, e o uso da areia de extração provoca a degradação do meio ambiente. Utilizar a areia de britagem para substituir a areia natural é uma forma de contribuir para a preservação ecológica. / The goal of this resarch is to identify the behavior of limestone crushed sand in coating mortar. Five trace compositions were proposed and tested: the first one made up of 100% natural sand, which will be used as reference trace, the second composition presented 80% natural sand and 20% limestone rock crushed sand, the third one 60% natural sand and 40% limestone rock crushed sand, the fourth one with 40% natural sand and 60% limestone rock crushed sand, and the fifth trace 20 % natural sand and 80% limestone rock crushed sand. The mortar traces were composed of cement, sand, water and additive, without the presence of lime, and these were tested in the wet and hardened state and presented the following results: Composite traces with limestone rock crushed sand presented better performance than the reference trace, which had only natural sand. The traces with 60% natural sand and 40% limestone crushed sand showed better performance in 70% of the tests performed, and presented a grain size curve within the optimal upper and lower zone, as required by the standard rules. The relevance of this study is due to the fact that crushed sand is a waste that generates important environmental liability, and natural sand extraction leads to the environmental degradation. Using crushed sand to replace natural sand is one way to contribute to environmental preservation.