The pozzolanic reactions, responsible for the resistance of soil-lime blends, are endothermic. As such, increasing the curing temperature in turn increases the strength of lime-stabilized soil. Recent research has shown that there is a maximum limit to the resistance of a specimen, based on its curing time. This study aims to predict the maximum tensile strength of sand-coal fly ash-lime blends for several curing times. To achieve that, a series of splitting tensile tests were carried out using cylindrical specimens with diameter and length equal to 50 mm and 100 mm, respectively. Lime content varied from 3% to 7%, dry unit weight ranged from 14 kN/m 3 to 16 kN/m 3 , curing temperatures were 20, 35, 50, 65, 80 and 90°C, curing periods were 1, 3 and 7 days and fly ash content was established as 25%. Results show that the increase in curing temperature boosts the tensile strength of sand-coal fly ash-lime blends up to a limit that varies with curing time. The porosity/lime index, defined as the ratio of the compacted mixture's porosity and volumetric lime content adjusted by an exponent, proves to be an appropriate parameter to estimate the splitting tensile strength of the soil-coal fly ash-lime studied for all curing times and temperatures studied. Using this index, curves were obtained for the calculation of the maximum temperature that influences the resistance of the studied mixture for each curing time. An equation capable of determining the maximum resistance that can be reached in each curing time, independent of curing temperature, was also obtained through the index.

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VASPS (Vertical Annular Separation and Pumping System) is an innovative concept for two-phase subsea separation and pumping system. This paper reports the latest efforts being taken in the development of such technology prior to the installation of the first subsea prototype, presenting a summary of the results of high viscosity tests onshore in the Atalaia Test Site, Brazil. It also provides an outlook of the final phase of the VASPS project, where a subsea VASPS unit will be installed at the Marimba field, Campos Basin, offshore Brazil. Introduction Several papers1–3 discussing the potential of subsea boosting technologies for oil production from deepwater fields have been published in recent years. Assayag et al.1 present a comprehensive review of the subject, outlining its advances, trends and challenges. Among these technologies, subsea separation has been considered one of the most promising alternatives2,4 VASPS (Vertical Annular Separation and Pumping System) is an innovative concept for two-phase subsea separation and pumping system, which allows a high capacity integrated separation and pumping equipment to be installed within a 30" conductor in a dummy well. This compact configuration is obtained by the use of internals which, without moving parts, induce helical flow path within the unit, thus generating centrifugal forces which enhance the gas-liquid separation (Fig. 1). The installation and maintenance of the unit are conceived to be accomplished using conventional subsea dri1ling and completion technology and equipment. VASPS technology is being developed in a phased approach addressing the various issues in a hierarchical manner Benneti & Villa4. Ref. 4 also describes the previous phase of the VASPS project development, in which a large scale surface prototype was tested in ENI-Agip's Multiphase Test Loop at Trecate, in Italy. Those tests confirmed the viability of the concept over a wide range of test conditions, with liquid viscosity ranging from 1–6 cPo The following step was to evaluate the gas-liquid separation performance with higher viscosity oils. These tests, part of the so caned "VASPS PreSubsea Phase", included testing of improved separator geometry and of associated technology, such as level sensors and control systems. Tests with high viscosity oils were performed at the Petrobras' Test Site for Multiphase Equipment at Atalaia, Brazil, using four different oils, with viscosities ranging from 5-65 cPo The results achieved validated both the separation process and the VASPS design models for such conditions. In particular, models' forecasted separation performances were compatible with those experimentally obtained. This paper also provides an outlook of the final phase of VASPS project's developments where a subsea VASPS unit will be installed in the Marimba field, Campos Basin, offshore Brazil. Tests of VASPS as a Separator in Atalaia After successfully testing a VASPS prototype as a separator for gas and low viscosity oils at ENI-Agip's Trecate Test Site, the whole assembly was brought to the Atalaia Test Site, in Northeastern Brazil, in order to have its performance evaluated when using higher viscosity oils. It is important to stress that this prototype was not specifically designed to the conditions of the Atalaia tests.

A necessidade de reserva de água para os usos múltiplos como abastecimento, geração de energia e reserva, leva a ciência a se mostrar eficiente no desenvolvimento de tecnologias para controlar os elementos naturais e assim satisfazer as necessidades geradas pelo desenvolvimento econômico e social. Nesse sentido, as barragens de terra são elementos amplamente utilizados para este fim. Neste contexto foi analisada a influência, com a quantificação em vazão, de um solo residual tratado com cal e resíduo da britagem do Basalto, aplicado em forma de um núcleo cimentado a uma barragem de terra zoneada, para controle da percolação utilizando o Método dos Elementos Finitos (MEF). À área referente ao núcleo aplicou-se ao mesmo material o agente cimentante, cal dolomitica em teores de 5, 7 e 9%. O peso especifico aparente seco do núcleo foi variado nos níveis de 16, 17,2 e 18,5 kN/m³. Avaliaram-se três seções transversais trapezoidais de núcleo cimentado, onde a base menor foi fixada em 8 metros e a base maior variou em 20, 45 e 70 metros. Os resultados analisados mostram que o teor de cal aplicado não tem influência direta na redução da percolação, mas que o peso específico aparente seco tem papel fundamental, com maior amplitude de redução para núcleos com bases menores, ainda mostrando a possibilidade da otimização do núcleo tratado com base na metologia razão ɳ/Liv.