PubMed | Physiolution GmbH, Polish Academy of Sciences, Wroclaw Medical University, Pedagogical University of Cracow and 2 more.
Type: Comparative Study | Journal: International journal of pharmaceutics | Year: 2016
The purpose of the research was to investigate the effect of the manufacturing process of the controlled release hydrophilic matrix tablets on their hydration behavior, internal structure and drug release. Direct compression (DC) quetiapine hemifumarate matrices and matrices made of powders obtained by dry granulation (DG) and high shear wet granulation (HS) were prepared. They had the same quantitative composition and they were evaluated using X-ray microtomography, magnetic resonance imaging and biorelevant stress test dissolution.Principal results concerned matrices after 2 h of hydration: (i) layered structure of the DC and DG hydrated tablets with magnetic resonance image intensity decreasing towards the center of the matrix was observed, while in HS matrices layer of lower intensity appeared in the middle of hydrated part; (ii) the DC and DG tablets retained their core and consequently exhibited higher resistance to the physiological stresses during simulation of small intestinal passage than HS formulation.Comparing to DC, HS granulation changed properties of the matrix in terms of hydration pattern and resistance to stress in biorelevant dissolution apparatus. Dry granulation did not change these properties-similar hydration pattern and dissolution in biorelevant conditions were observed for DC and DG matrices.
Labus M.,Silesian University of Technology |
Such P.,Oil and Gas Institute National Research Institute
Journal of Petroleum Science and Engineering | Year: 2016
One of the most important aspects of the interaction between well-bore cement and the formation rock are the porosimetric parameters of both materials. Porosity and pore-size distribution affect the behaviour of the porous solid material, including the fluid movement and flow. In order to analyse the porosity of rock and cement material in the presented investigation the following procedures were applied: mercury intrusion porosimetry (MIP), gas adsorption technique and X-ray microtomography (XMT). The investigation proved the usefulness of XMT method, which enables the microstructural characterisation of the composed (cement-rock) samples during the subsequent stages of the experiment. Imaging the cement degradation in the rock-cement contact zone is possible, thanks to the differentiated densities of the altered zones, resulting from the rock or cement dissolution, and new phases precipitation. Five rock samples of different lithology (quartzitic sandstone, eolian sandstone, shale, limestone and anhydrite) were selected for the examination. The prepared samples composed of well bore cement and rock were exposed to CO2-saturated brine, under static conditions. Basing on the shape of the gas adsorption isotherms the classification of the materials (cement and rocks) was performed. In the case of the rocks classified as macroporous, because of the porosity characteristics close to those of cement, the CO2 saturated brine flow is uniform in both materials (cement and rock), and the dissolution and precipitation processes are less intense. The obtained results seem to be very useful for predicting the integrity of wellbore, in case of different caprock and reservoir rock. © 2015 Elsevier B.V.
Jarzyna J.A.,AGH University of Science and Technology |
Krakowska P.I.,AGH University of Science and Technology |
Puskarczyk E.,AGH University of Science and Technology |
Wawrzyniak-Guz K.,AGH University of Science and Technology |
And 5 more authors.
Computational Geosciences | Year: 2016
The main goal of the research was to employ the unique data delivered by various methods to improve the determination of rock reservoir properties. Results of X-ray computed tomography (XRCMT), one of the newest techniques providing high-resolution images of rocks, were used to show that very precise information from this tool is complementary to results from other methods. Standard laboratory measurements (helium pycnometer, mercury injection porosimetry, permeameter) and sophisticated experiments (X-ray computed tomography and nuclear magnetic resonance spectroscopy) were performed to obtain and compare results. Four types of specimens: typical Miocene sandstone-mudstone-claystone rock samples, artificial corundum specimens, shale gas plugs, and limestone sample were investigated to obtain the porosity, permeability, density, and other parameters used in rock descriptions. Mutual relationships between selected groups of rock material properties were presented to provide an integral picture of rock characteristics. The XRCMT results were in general not influenced by lithology, but there were observed shaliness effects on the shape of pores, cross sections, and the tortuosity of porous channels. An analysis of the average porosity and the standard deviation of each XRCMT plot provided information about differences in the heterogeneity of a formation. Thus, the XRCMT method was recommended in pore space parameter determination for microfracture fluid propagation monitoring. There was also observed equivalence between part of the NMR signal from clay-bound water and the XRCMT volume subgroups in porosity/permeability—structural classes I and II. So, the use of the two-subsample approach in the XRCMT interpretation was promoted. © 2016 The Author(s)
Radzikowski K.,Warsaw University of Technology |
Nowak R.,Warsaw University of Technology |
Arabas J.,Warsaw University of Technology |
Budak P.,Oil and Gas Institute National Research Institute |
Latkowski P.,Oil and Gas Institute National Research Institute
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016
In this article we propose the algorithm for computing the degree of similarity between two shale gas boreholes. The algorithm uses data and measurements from already existing and examined boreholes, and uses K-nearest neighbours algorithm for calculating the similarity between each known borehole, and a new borehole, as a form of classification. Several experiments were conducted, in order to assess the complexity and correctness of the algorithm. This article describes the proposed method, and the experiments, as well as results. © 2016 SPIE.
Urzedowska W.,Oil and Gas Institute National Research Institute |
Stepien Z.,Oil and Gas Institute National Research Institute
Fuel Processing Technology | Year: 2016
It is well known that the reduced stability of FAME diesel fuel blends is of particular threat to diesel engines and especially high pressure common rail (HPCR) systems operation. As has been ascertained, internal diesel injector deposits are more likely to form in modern diesel fuel systems because of their higher operating pressures and temperatures, which can intensify oxidation and decomposition of the chemically unstable components of diesel fuels, particularly those contained in FAME. This paper presents the results of accurate and sensitive evaluation of laboratory test methods for the determination of oxidation, storage and thermal diesel fuel stability, verified via dynamometer engine testing, from the point of view predicting the possibility of threats caused by aged diesel fuel with various FAME contents for HPCR in-system performance. © 2015 Elsevier B.V. All rights reserved.
Kozak J.,Jagiellonian University |
Paluch J.,Jagiellonian University |
Wegrzecka A.,Jagiellonian University |
Kozak M.,Oil and Gas Institute National Research Institute |
And 3 more authors.
Talanta | Year: 2015
Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of asingle peak. In the developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into aholding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming amore stable colorless compound with Fe(III), acomplex signal is registered. Measurements are performed at wavelength 530nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04-4.00 and 0.1-5.00mgL-1, with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09mgL-1 for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples. © 2015 Elsevier B.V.