This work deals with the study of limestone and corundum dry milling using attritor-type stirred mill in a batch mode. There were stearin and polyethylene glycol used as surfactants and spherical shaped steel grinding elements used for the experimental part of the work. The main idea was to examine behavior of the selected grinding stock type within a long-term grinding forces exposure in selected conditions of ultrafine dry milling leading up to the submicron area. Characterization of samples was performed by laser granulometry, X-ray powder diffraction analysis, flame atomic absorption spectroscopy, objective color determination and electrokinetic potential measurement. Experimetaly measured data implies that in all cases there was a re-agglomeration of the grinding stock particles occurring, although in different stages of the disintegration process and in mutually various degree. The analysis results denote that a larger erosion of the crystal structures with the associated increase of the amorphous phase in the submicron particle size took place in the grinding stock.

Orientador: Enes Furlani Júnior / Banca: Marcelo Andreotti / Banca: Ederaldo José Chiavegato / Resumo: O objetivo foi avaliar a eficiência da calagem e gessagem para o cultivo de algodão, que foram submetidos a diferentes modos de aplicação de fertilizante na semeadura, em região de Cerrado. O experimento foi desenvolvido na Fazenda experimental de Ensino, Pesquisa e Extensão da FE/Unesp, localizado no município de Selvíria-MS (20º22'S e 51º22'W e 335 m de altitude), num LATOSSOLO VERMELHO DISTROFÉRRICO. O delineamento experimental utilizado foi blocos ao acaso, em esquema fatorial 4x3, sendo o primeiro fator manejo da calagem e gessagem (calagem, gessagem, calagem+gessagem, testemunha); o segundo fator foi o modo de aplicação do adubo na semeadura (sulco, à lanço, testemunha), sendo que quando foi efetuada a análise em profundidade, esta foi considerada como o terceiro fator, em um esquema 4x3x3 e as profundidades de 00-10, 10-20 e 20-30 cm, com 4 repetições. Aos 85 dias após emergência (DAE) avaliou-se os teores de macronutrientes foliares das plantas. E ainda no final do ciclo da cultura determinou os componentes de produção (massa de 20 capulhos, massa de 100 sementes, % de fibra e produtividade) e análise de macronutrientes no solo em diferentes profundidades, após a colheita. A calagem proporcionou acréscimos nos teores de Ca, Mg, aumentou os valores de Soma de Bases (SB) e V% . A calagem aumentou o pH do solo, assim reduzindo os teores de Al de H+Al. O gesso não altera o pH do solo, porém a gessagem associada com adubação aplicada à lanço reduziu H+Al e Al, aumentou os valores de SB, além do teor de Ca. O teor foliar de Mg foi alterado pela calagem, sendo que a gessagem proporciona aumentos no S foliar do algodoeiro / Abstract: The objective was to evaluate the efficiency of the limestone, and gypsum in the ground tillage of cotto crop was submitted to different methods of fertilizer application in the sowing. The esperiment was developed in the experimental Farm of the São Paulo State University FE/Unesp, located in the city of Selvíria-MS (20º22' S and 51º22' W and 335 altitude m, in Dark Red Latossol with midian texture. The experiment design delineation was te completely blocks in the sysytem factorial 4 X 3 with the first factor: lamestone and gypsum application with four types; a) limestone, b) gypsum, c) limestone + gypsum and d) control. And the second factor was: a) fertilizer on the ridge, b) fertilizer moad carled, and c) control. With 4 repetition. At 85 days after sowing the leasf content of nutrients was evaluated. In the harvest, the production componets (mass of 20 bolls weight, weight of 100 seeds, % of lint and yield, and soyl analizing in different depths were colhected. It's concluded that levels of Ca, Mg, K, SB and value V% and pH in the soil and reduce Al and H+Al. Gypsum does not modify pH. The foliar levels of Mg was modified by the limestone and the gypsum provides the increase in the foliar S of the cotton plant / Mestre

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface of calcite and in dilute calcium carbonate-P solutions. However, these reactions with their respective affinity constants from the literature fail to predict the behavior of P with calcite in seawater. In this study, we conducted a series of batch experiments involving both adsorption and desorption of P in seawater, freshwater, dilute seawater, and mixtures of seawater and freshwater. We used these results in the geochemical model PHREEQC and the parameter estimation model PEST to optimize the affinity constants for the existing surface reactions. We found that after making minor adjustments to the affinity constants, the existing surface complexation models of calcite surface reactions from the published literature are sufficient to explain seawater-induced P desorption. Specifically, our results suggest that CaPO4- and either CaHPO40 or HPO42- may be important species in the P adsorption/desorption reactions in freshwater-seawater mixing.

Nordwestlich des Zentrums der alten Forststadt Tharandt ist auf noch Tharandter und Hintergersdorfer Flur ein Lager von Kalkstein eingeschaltet. An dem nach Norden gerichteten Teil des Talhanges an der großen Biegung der Talmühlenstraße Richtung Ebergrund - Hartha, lag das ehemalige Kalkwerk Tharandt. Hier trat der Kalkstein an der Tagesoberfläche hervor. Es ist deshalb nicht verwunderlich, dass hier schon von alters her seine Gewinnung und das "Brennen" vorangetrieben wurde. ... (aus dem Text)

This master thesis comprises results of sedimentologic, microfacies and physical stratigraphic research of the Suchomasty Limestone at Zlatý kůň Hill near Koněprusy (Prague Basin, Lower Devonian - Dalejan). Six instructive sections have been selected for detailed study. Physical stratigraphic records (MS and GRS) have been used for correlation of two lithologically different sections (Section I - to the East of the Herget Quarry and Section IV - near the entrance to the Koněprusy Caves). This comparison showed that both sections correspond to the same stratigraphic level, and thus can be included in one sedimentary system. This assumption is also supported by preliminary results of studies on stratigraphic distribution of conodonts. Stratigraphic variations in MS and GRS may also be used for reconstructions of sedimentary environment and its evolution (e.g., changes in sea level). However, all measured parameters show only low oscillations and reflect probably only local conditions. Five microfacies types corresponding to three facies belts have been identified in the studied sections. The lower part of the Suchomasty Lm. is dominated by fine-grained limestones (MF 1 - tentaculite wackestone/packstone) in the NW part of the area (Section IV - near the entrance to the Koněprusy Caves). They deposited in a...

In this thesis, the succession of spider assemblages in five limestone quarries of different ages in Bohemian Karst has been studied. The main goal of this paper was studying changes of spider assemblages along successional gradient. Furthermore, different environmental factors affecting spider communities and also assemblages of spider communites in different terraces of the quarry have been studied. Standardized methods (pitfall traps, hanging desk traps, shifting leaf litter, sweeping of herb vegetation, and beating shrubs) have been used for recording the highest possible richness of spiders. The results showed that position of the terraces and the age of the quarry do not affect species richness and density. Species density of epigeic spiders increased significantly with number of the plant species. The results showed that spiders do not have their own succession, but they are following vegetational succession. The environmental factors which affect species composition of spiders from the pitfall traps are positon of terraces, shading and moss cover. Although the age of the quarry was insignificant for spiders from pitfall traps, every quarry was inhabited by different spider communities. Shrubs and tree-dwelling spiders showed correlations with the age of the quarry. Data recorded from...

Deep geological repositories (DGR) are considered an effective long-term solution for radioactive waste disposal. Sedimentary (argillaceous formations) and crystalline rocks are currently under investigation worldwide as potential host formations for DGR. Their low porosity (<1-2 %) and very low hydraulic conductivity result in diffusion-dominated solute transport. There is a need to investigate their diffusion properties in detail, the long-established diffusion methods do not allow an evaluation of the spatial relationship between tracers and the characteristics of the geological medium. The aim of this project was to measure diffusion coefficients in low-porosity rocks (< 2%) using X-ray radiography and iodide tracer. The method is a non-destructive technique based on the principle of X-ray attenuation; it provides temporal- and spatially-resolved information of a highly attenuating tracer diffusing in a sample. Samples from the Cobourg Formation, an Ordovician argillaceous limestone from the Michigan Basin, and from the Lac du Bonnet batholith, an Archean granitic pluton were used in this study. X-ray radiography data from the Cobourg Formation indicate tracer accumulation occurs on dark argillaceous layers in the rock characterized by clay minerals and organic matter. It is proposed that the I– tracer solution underwent photo-chemical oxidation, leading to the formation of I2, a highly reactive volatile iodine species and I3–, which readily reacted with humic substances contained in the clay- and organic rich zones in the limestone samples. In the case of the granitic samples, attempts at measuring diffusion coefficients encountered several challenges. The results indicate that tracer signal can be detected, however diffusion signal is masked by imaging errors and noise.

The Twin Creek Limestone of Middle Jurassic age was studied in the Tunp, Salt River, and Wyoming Ranges in southwestern Wyoming. Modern carbonate environments and their ancient analogs were compared with information obtained from field study and petrographic analysis of samples of the Twin Creek Limestone in order to delineate environments of deposition, paleogeography, and diagenetic history. Six major lithofacies were recognized: (1) carbonate mudstone; (2) carbonate mudstone breccia; (3) fossiliferous wackestone; (4) packstone-grainstone; (5) terrigenous mudstone; and (6) sandstone. These lithofacies were deposited in a variety of environments, including outer shelf platforms (carbonate mudstone and fossiliferous wackestone), oolitic sand belts (packstone-grainstone), open to restricted lagoons (carbonate mudstone, fossiliferous wackestone, and terrigenous mudstone), tidal flats, and supratidal environments (terrigenous mudstone, sandstone and carbonate mudstone breccia). The Twin Creek epeiric seaway experienced two major transgressions (early Bajocian and late Bathonian-early Cal lovian) and two regressions (early Bathonian and middle Callovian). Lateral migration of the adjacent facies occurred in response to these changes in sea level. Eogenetic features include minor compaction, micritization, coarse fibrous rim cementation, granular cementation, syntaxial rim cementation and silicification of carbonates. These features were produced in environments ranging from freshwater phreatic to marine phreatic. Mesogenetic diagnesis was characterized by pressure-solution features and neomorphism. Telogenetic features are limited to calcite vein-fillings and oxidation coatings on carbonate and detrital gains and cements.

Community succession, the orderly changes a community experiences with time, is considered to be the result of either autogenic or allogenic factors working singularly or in combination. It has been further suggested that, as communities undergo succession, certain biological parameters change in a predictable manner. Examination of members 2 through 4 of the Mississippian (KinderhookOsage) Lodgepole Formation of Samaria Mountain, Idaho provides a means to evaluate these concepts. Within the study section comprised of 125 beds (61.5 m thick), four rock types are recognized. These include: (1) fossiliferous wackestone (78% of beds), which ranges in color from dark-gray (N3) to medium-light gray (N6), is fine to coarse crystalline, has an average insoluble content of 3.1 percent by weight, and an average organic content of 0.25 percent by weight; (2) fossiliferous mudstone (1S% of beds), which ranges in color from dark-gray (N3) to medium-gray (NS), is very fine to fine crystalline, has an average insoluble content of 2.3 percent and an average organic content of 0.30 percent by weight; (3) fossiliferous packstone (6% of beds), which ranges in color from medium-gray (NS) to light-gray (N7), is medium to coarse crystalline, has an average insoluble content of 3.3 percent by weight and an average organic content of O. 17 percent by weight; and (4) crystalline carbonate (1% of beds), which is light-gray (N7) in color, is coarse crystalline, has an insoluble content of 9.3 percent by weight, and an organic content of 0.2 percent by weight. However, at ninety-five percent confidence level, no statistical relationship could be seen between the rock types and either the insoluble contents or the organic content. Twenty-one taxa, including corals, brachiopods, crinoids, blastoids, gastropods, echinoids, and sharks were recognized, with most taxa ranging throughout the study section. Well-preserved fossils are generally rare. However, this deficiency seems to be due to weathering of the containing strata rather than to currents acting on the skeletons prior to burial. Orientational data support this conclusion. Measurements of the direction (vector) from the apical end to the calical end of the horn coral Zaphrentis show that the orientations of toppled corals is random. Two biological parameters are calculated for each of the bedding surfaces examined, i.e., diversity and calcified biovolume. Diversity is calculated two ways, i.e., in terms of equitability, and in terms of richness. For richness, values range from 0.0 to 7.41, with a mean of 4.12, and for dominance diversity, values range from 0.0 to 1.95, with a mean value of 0.87. Calcified biovolume, which is used as the basis for inferences involving biomass, ranges from 0 to 30,015 cubic centimeters per bedding surface, with a mean value of 744.1 cubic centimeters per bedding surface. Three faunal associations, as well as several sub-associations within the three major associations, are indicated by the clustering of indices of affinity. These associations include: (1) Zaphrentis-Crinoid- Syringopora-Echinoid-Cleiothryridina-Unispirifer-Spirifer-Orthotetes- Flexaria-Camarotoechia-Schizophoria-Lithostrotionella; (2) Cruziana-Dwelling tube; (3) Shark-Blastoid-Helminthopsis. Trophic relationships within the three associations suggest that they were the result of two factors: (1) the tendency towards a vertical stratification of the association's members, which resulted in a more efficient use of the water column; (2) direct physical interaction among association members, in the form of predator-prey or symbiotic relationships. The former type of interaction may have been operative between the sharks and blastoids of faunal association 3. Environmental reconstruction involved the determination of four parameters: (1) paleocurrent direction and intensity; (2) sedimentation rate; (3) bathymetry; and (4) substrate. From the study of both physical and biological evidence, it is concluded that, during the time of Lodgepole deposition a very weak, unidirectional current, or multidirectional currents of similar competency operated over a carbonate-mud substrate. Evidence suggests that the sedimentati on rate was extremely low, and that the Eh= 0 line was just below the sediment-water interface. The water depth at this location was probably below normal effective wave base, but above the zone of oxygen depletion. Study of fossils on bedding surfaces overlying barren bedding surfaces or surfaces containing fossil hash, suggests that four successional stages can be recognized. Because changes in the faunal composition between the various successional stages appear to take place both with (10 times), and without lithologic changes (16 times), it is concluded that succession may result from either biological modifications of the environment or physical changes. Therefore, succession was both autogenically or allogenically controlled. Additionally, the comnrunities were retrograded to an "earlier" successional stage 24 times within the 125 bed succession. As succession proceeded through the successional sequence, values for equability-diversity and calcified biovolume generally increase. This trend is in agreement with previously predicted trends. With succession the overall trend observed in the trophic structure appears to be one of an increase in the proportion of filter feeders in the community relative to the proportion of deposit feeders in the community.

The thesis is focused on the study of the use of fluidized bed fly ash as part of the raw mealfor firing Portland clinker in order to reduce carbon dioxide emissions. It is aimed atoptimizing the cutting mode belit cement to increase its reactivity.