Towards modelling physical and chemical effects during wettability alteration in carbonates at pore and continuum scales

Understanding what controls the enhanced oil recovery during waterflooding of carbonate rocks is essential as the majority of the world’s remaining hydrocarbon reserves are contained in carbonate rocks. To further this understanding, in this thesis we develop a pore-scale simulator that allows us to look at the fundamental physics of fluid flow and reactive solute transport within the porous media. The simulator is based on the combined finite element – finite volume method, it incorporates efficient discretization schemes and can hence be applied to porous domains with hundreds of pores. Our simulator includes the rule-based method of accounting for the presence of the second immiscibly trapped fluid phase. Provided that we know what chemical conditions initiate enhanced oil recovery, our simulator allows us to analyse whether these conditions occur, where they occur and how they are influenced by the flow of the aqueous phase at the pore scale. To establish the nature of chemical interactions between the injected brines and the carbonate rocks, we analyze the available experimental data on the single-phase coreflooding of carbonate rocks. We then build a continuum scale simulation that incorporates various chemical reactions, such as ions adsorption and mineral dissolution and precipitation. We match the output of the continuum scale model with the experimental data to identify what chemical interactions the ions dissolved in seawater are involved in

Комплексный анализ прогностической значимости аберраций хромосомы 8 у пациентов с увеальной меланомой

Introduction. Uveal melanoma ability to metastasize depends on a few prognostic factors. The genetic ones are considered to be the most significant. The role of disorders of the short arm of chromosome 8 (8p), as well as a combination of changes in 8p and the long arm of this chromosome (8q) in the development of metastatic lesions in this pathology remains insufficiently studied.The study objective – to evaluate the prognostic value of chromosome 8 abnormalities in patients with uveal melanoma.Materials and methods. We analyzed 2 retrospective groups of patients who underwent enucleation for uveal melanoma, statistically homogeneous in the main clinical parameters. Group 1 included patients without signs of metastases (n = 41) with an average follow-up period of 71 months, Group 2 included patients with detected metastases (n = 51) and an average follow-up period of 21 months Chromosome abnormalities were tested by multiplex ligation-dependent probe amplification.Results. Three- and five-year survival in patients with uveal melanoma without 8p deletion were 64 and 54 %, respectively; with 8p deletion significantly lower – 25 and 6 %, respectively. The same survival rates in patients with uveal melanoma with 8q amplification were 43 and 26 %, respectively, whereas in patients without 8q amplification they were significantly higher – 80 and 74 %, respectively. In patients with uveal melanoma harbouring both abnormalities, 3- and 5-year survival rates were 26 and 7 %, whereas isolated 8q amplification was associated with 47 and 35 % survival, respectively. These survival rates differ greatly and significantly: hazard ratio 3,26 (95 % confidence interval 1,86–5,69) and 6,89 (95 % confidence interval 2,67–17,73), respectively (р <0,0001).Conclusion. The findings support comprehensive evaluation of chromosome 8 abnormalities as a substantial part of uveal melanoma prognostication. 8q amplification, 8p deletion, combination of these abnormalities and its role in uveal melanoma malignity should be further discovered. Further research in this direction is needed.Введение. Способность увеальной меланомы к метастазированию зависит от целого спектра прогностических факторов, среди которых генетические имеют основополагающее значение. Роль нарушений короткого плеча хромосомы 8 (8р), а также комбинации изменений 8р и длинного плеча этой хромосомы (8q) в развитии метастатического поражения при данной патологии остается недостаточно изученной.Цель исследования – проведение комплексного анализа прогностической значимости аберраций хромосомы 8 у пациентов с увеальной меланомой.Материалы и методы. Были проанализированы 2 ретроспективные группы пациентов, которым была проведена энуклеация по поводу увеальной меланомы, статистически однородные по основным клиническим параметрам. В 1-ю группу вошли больные без признаков метастазов (n = 41) со средним сроком наблюдения 71 мес, во 2-ю группу – больные с выявленными метастазами (n = 51) и средним сроком наблюдения 21 мес. анализ хромосомных нарушений проводился методом мультиплексной амплификации лигированных зондов.Результаты. Трех- и 5-летняя выживаемость пациентов с увеальной меланомой без делеции 8p составила 64 и 54 %, с делецией 8p – 25 и 6 % соответственно. У больных с амплификацией 8q эти показатели были равны 43 и 26 %, у больных без амплификации 8q – 80 и 74 % соответственно. Для пациентов с одновременной амплификацией региона 8q и делецией региона 8р 3- и 5-летняя выживаемость составила 26 и 7 %, тогда как для пациентов с изолированной амплификацией 8q – 47 и 35 % соответственно. Уровень выживаемости пациентов с изолированной амплификацией 8q и комбинацией нарушений (del8p + amp8q) различается существенно и достоверно: отношение рисков 3,26 (95 % доверительный интервал 1,86–5,69) и 6,89 (95 % доверительный интервал 2,67–17,73) (р <0,0001).Заключение. Оценка амплификации 8q, делеции 8p и комбинации этих нарушений должна стать неотъемлемой частью прогнозирования риска метастазирования увеальной меланомы. Необходимы дальнейшие исследования в этом направлении

Insights into non-Fickian solute transport in carbonates

[1] We study and explain the origin of early breakthrough and long tailing plume behavior by simulating solute transport through 3‐D X‐ray images of six different carbonate rock samples, representing geological media with a high degree of pore‐scale complexity. A Stokes solver is employed to compute the flow field, and the particles are then transported along streamlines to represent advection, while the random walk method is used to model diffusion. We compute the propagators (concentration versus displacement) for a range of Peclet numbers (Pe ) and relate it to the velocity distribution obtained directly on the images. There is a very wide distribution of velocity that quantifies the impact of pore structure on transport. In samples with a relatively narrow spread of velocities, transport is characterized by a small immobile concentration peak, representing essentially stagnant portions of the pore space, and a dominant secondary peak of mobile solute moving at approximately the average flow speed. On the other hand, in carbonates with a wider velocity distribution, there is a significant immobile peak concentration and an elongated tail of moving fluid. An increase in Pe , decreasing the relative impact of diffusion, leads to the faster formation of secondary mobile peak(s). This behavior indicates highly anomalous transport. The implications for modeling field‐scale transport are discussed

ПРЕДПОСЫЛКИ СОЗДАНИЯ ПЕРСПЕКТИВНОГО АППАРАТА НЕИНВАЗИВНОЙ ЛУЧЕВОЙ МЕДИЦИНСКОЙ ДИАГНОСТИКИ НА ОСНОВЕ МИКРОВОЛНОВОГО ИЗЛУЧЕНИЯ

Background for development of perspective apparatus for non-invasive medkal radiation diagnostics of functional state of inner organs and tissues on the base of application of microwave sensing and visualization techniques in non-ionizing range of electromagnetic spectrum safe for human organism, practically implemented using smart antenna array, is given. Perspective medical apparatus will have previously unachievable functional technological characteristics, particularly - principal possibility of high-resolution visualization of organs and tissues without using any contrast agents and costing less in comparison with existing systems of computer, magnetic resonance and positron emission tomography on the market.Обоснована возможность создания перспективного аппаратного комплекса неинвазивной медицинской лучевой диагностики функционального состояния внутренних органов и тканей на основе применения методов микроволнового зондирования и визуализации в неионизирующей области электромагнитного спектра с безопасной дозой излучения для организма человека, реализуемых на практике с помощью использования адаптивной цифровой антенной решетки. Перспективный диагностический комплекс будет иметь ранее недостижимые функциональные технологические свойства, в частности, возможность высокоразрешающей визуализации органов и тканей без использования контрастных веществ, обладая при этом более низкой стоимостью по сравнению с существующими системами компьютерной, магнитно-резонансной, позитронно-эмиссионной томографии на рынке

Decoring Behaviour of Chosen Moulding Materials with Alkali Silicate Based Inorganic Binders

This paper contains basic information about new processes for cores for cylinder heads production with alkali silicate based inorganic binders. Inorganic binders are coming back to the foreground due to their ecologically friendly nature and new technologies for cores production and new binder systems were developed. Basically these binder systems are modified alkali silicates and therefore they carry some well-known unfavourable properties with their usage. To compensate these disadvantages, the binder systems are working with additives which are most often in powder form and are added in the moulding material. This paper deals with decoring behaviour of different moulding sands as well as the influence of chosen additives on knock-out properties in laboratory terms. For this purpose, specific methods of specimen production are described. Developed methods are then used to compare decoring behaviour of chosen sands and binder systems