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<p class=MsoNormal>Decreasing strength with increasing effective compressive strength, referred to as "cap" behavior is often attributed to pore collapse and a reduction in pore throat apertures during early drawdown. Over-consolidation with only a slight increase in effective stress creates secondary fine particles that leads to formation damage and permeability decline. Grain crushing and the creation of a secondary fines population exacerbates pore blockage that results from mobilization of loosely attached kaolinite or other non-load bearing fine particles. Pore volume compressibility data indicate that compaction effects are significant and pose a potentially serious production problem during depletion. Pore volume lost during depletion is non-recoverable and will not "rebound." Re-injection of water will not re-establish the pore volume lost during compaction as a result of reservoir depletion. Compressibility and compaction trends in the Lower Captain Sandstone contradict several petroleum industry theories. Effective confining pressure and effective mean stress were higher under uniaxial strain boundary versus triaxial conditions and play a greater role in compaction than shear stresses. Captain <i>pseudo shales </i>exhibit strain-softening behavior and peak strengths are quite close to residual strengths. Captain <i>pseudo shales </i>clearly have residual load-bearing capacity and strain-softening promotes plasticicity.  Use of standard core analysis methods to measure pore volume compressibility and fines migration potential are highly discouraged in unconsolidated as well as consolidated sandstones. Petrographic, mineralogical, and routine petrophysical analyses are essential in the interpretation of rock mechanics data.

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Given the high costs and general shortage of coking coals on the domestic and international markets, and because the nature and qualities of many of the coking coals available on the markets are themselves mixed products, conventional mechanisms and tried and trusted formulae for manufacturing coke products based on single coals of known qualities can no longer apply. There is therefore an urgent need to develop more effective techniques for evaluating and assessing the properties of individual coals rapidly and reliably and in a manner that could provide useful data for use in modelling the effect of new coal components in a coke blend. Towards this end, the current research has sought to find more accurate coal characterisation techniques at laboratory scale than currently exists in industry at present. Seventeen coking or blend coking coals from widely different sources were selected and cokes were produced from them in as close to full scale conventional conditions as possible. Both coals and cokes were analysed using conventional chemical, physical, petrographic and rheological coking methods. The results indicated that, whilst all coals had acceptable chemical, physical and petrographic properties as evaluated on individual parameters thereby indicating their potential values as prime coking coals, in fact the resultant cokes of some of the coals had properties that disproved this assessment. These anomalies were investigated by integrating all characteristics and statistically evaluating them. The result [outcome] indicated that the series of coals under review fall naturally into three distinct categories according to rank, as determined by the reflectance of vitrinite, and that the coking coals in each rank category were further characterised by parameters specific to that level of rank. In this way more accurate predictions of coke quality were obtained than has been the case to date when using single set evaluations or previously devised formulae. On this basis it was concluded that, when selecting coals for coke making, it is essential to first establish the rank of the coal by vitrinite reflectance and then to apply coke evaluating parameters specific to that level of rank. The formulae developed for this purpose held good for all coals tested, however, it remains to be seen whether this applies universally to an even wider source of coals.

Made available in DSpace on 2014-06-11T19:26:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-10-15Bitstream added on 2014-06-13T20:54:26Z : No. of bitstreams: 1 ruiz_lmba_me_rcla.pdf: 5013284 bytes, checksum: 8e0476480ddec9386170f64c5424e861 (MD5) / O Maciço Sararé, pertencente ao Terreno Santa Helena no Cráton Amazônico, situa-se a cerca de 60 Km a norte da cidade de Pontes e Lacerda, sudoeste de Mato Grosso, apresentando o contato leste e nordeste recoberto pelas rochas sedimentares da Bacia Cretácica Parecis. Encontra-se intrusivo em rochas metamórficas do Complexo Vulcano-sedimentar Pontes e Lacerda em gnaisses e migmatitos ortoderivados (Complexo Metamórfico Alto Guaporé, Maciço Sapé e Anhanguera) de idades mesoproterozóicas. Compreende um corpo de 80 Km2, constituído por três fácies petrográficas graníticas principais, cujos contatos são transicionais. As rochas apresentam composição monzogranítica, são inequigranulares a localmente porfiríticas, granulação dominantemente média, constituídas por microclínio, quartzo, oligoclásio límpido ou saussuritizado , abundantes placas de muscovita (primárias ou secundárias), rara biotita cloritizada e fluorita metassomática, além de titanita e minerais opacos. A Fácies Biotita Monzogranito é dada por rochas equigranulares de granulação média-fina, cor avermelhada, leucocráticas, isotrópicas que ocorrem na porção sul do corpo. A Fácies Muscovita Monzogranito é representada por rochas inequigranulares, granulação média-grossa, cor rósea, hololeucocráticas e isotrópicas, que ocorrem na porção norte e central da intrusão. A ocorrência principal da Fácies Monzogranito aflora no extremo norte da área de forma isolada, como um plug granítico e dentro do maciço como diques aplíticos tardios. São constituídas por rochas leucocráticas, róseas, isotrópicas, ineqüigranulares a porfiríticas de granulação fina a média. A tectônica regional com direção NW-SE controla e define a forma alongada do Maciço Sararé acompanhando o trend regional de suas encaixantes. Tardiamente, uma tectônica rúptil manifestada através de fraturas... / The Sararé Granite belongs to the Santa Helena Terrain within the Amazonian Craton and is located about 60 km north of the city of Pontes and Lacerda, of southwest Mato Grosso. The east and northeast contacts of the body are marked by the sedimentary rocks of the Cretaceous Parecis Basin, while its remaining intrusive contacts are the metamorphic rocks of the Pontes and Lacerda volcano-sedimentary complex and orthogneisses and migmatites (Alto Guaporé Metamorphic Complex, Sapé and Anhangüera Massifs) of Mesoproterozoic age. The areal extent of the instrusion is approximately 80 km2 and is constituted by three major monzogranitic petrographic facies (biotite monzogranite, muscovite monzogranite and monzogranite) whose contacts are transitional. These rocks present monzogranitic composition, are unequigranular to locally porphyritic with medium grain size, constituted by microcline, quartz, oligoclase, abundant muscovite, rare cloritized biotite and metassomatic fluorite plus titanite and opaque minerals. Biotite monzogranitic facies is represented by equigranular of medium to small grain size, red-colored, leucocratic and isotropic rocks, that crop out in the southern portion of the body. The facies of muscovite monzogranite is represented by medium to coarse inequigranular textures, rose-colored, hololeucocratic and isotropic rocks that occur in the north and central portion of the intrusion. Monzogranite facies crops out in its main occurrence in the north end of the area and are interpreted as late-stage granitic plugs, constituted by inequigranular of medium to small grain size to porphyritic leucocratic rosy isotropic rocks. Their occurrence is characterized as localized intrusive bodies, including late aplite dikes, into the other ...(Complete abstract click electronic access below)

Trade between two regions often necessitates that the respective parties are political entities. This was indeed the case for trade between Egypt and the Levant during the Middle Bronze Age (ca. 2000-1550 BC, MBA) and Late Bronze Age (ca. 1550-1200 BC, LBA). Scientific analyses of Canaanite jars, transport vessels, from the site of Memphis, Egypt provided an ideal proxy for examining the relationship between trade and politics. During the MBA, Levantine peoples were present at the site of Tell el-Dabca in the eastern Nile Delta. However, archaeologically there is little evidence for contact between these peoples and the Egyptians at Memphis. Results of comparison of MBA Canaanite jars from both sites suggest the political situation fostered trade with the Levant and limited interaction with the Egyptians. During the LBA, Egyptian kings controlled territory in the Levant. A comparison of MBA and LBA Canaanite jars from Memphis revealed that the political changes in some cases affected the trade partners but not in others. Further, the production of the jars appeared to have altered in some regions. These results suggest that the affect of political situations on trade can vary, from only minor changes, to the complete exclusion of trade partners and the introduction of new trade contacts. However, the influence of lucrative trade networks on political developments was also illustrated. The utility of provenance studies of ceramics for understanding the complex relationship between trade and politics was confirmed.