160 research outputs found
Application of GIS in interpretation of the results of multistage hydraulic fracturing monitoring by surface microseismic method
Currently, the problem of interpretation of microseismic monitoring data is a critical task. Along with the improvement of field survey technologies and data processing, as well as with the development of realtime hydraulic fracturing monitoring by microseismic methods there are several problems to solve, such as objectivity of geological data, the data reference with the local and regional stress-strain state of the rock massif. The aim of this work is the post-processing of surface microseismic monitoring results with the use of geographic information systems. An analytical basis of data processing is spatial statistics set of tools of ArcGIS ESRI software, which is traditionally used to identify the patterns in the spatial distribution of any point events containing georeference component. The paper shows an approach to process an interpretation in complex situations, such as fracking pump failure, when the cloud of microseismic events shows a random distribution. Main attention in the work was paid for geological interpretation of the results obtained and their relation with the results of regional stress-strain state investigation. Significant convergence is detected for the orientation of natural fractures defined by surface seismic surveys, microseismic monitoring of hydraulic fracture propagation and regional lineament analysis basing on satellite images
'Click chemistry' in the synthesis of new amphiphilic 1,3-alternate thiacalixarenes
© 2015 Mendeleev Communications. Azidoalkyl-substituted 1,3-alternate p-tert-butylthiacalix[4]arenes were subjected to click reactions with alkynes affording thus novel amphiphilic derivatives of this series
PREDICTION OF METABOLIC TRANSFORMATIONS OF ORGANIC COMPOUNDS BY CYP1A2 ISOENZYME USING СONDENSED GRAPH OF REACTIONS
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Microwave-assisted Alkylation of p-tert-butylcalix[4]arene Lower Rim: The Effect of Alkyl Halides
Alkylation of p-tert-butylcalix[4]arenes with alkyl bromides or iodides under microwave irradiation affords mostly the corresponding distal disubstituted ethers, whereas in case of alkyl chlorides reasonable yields of monoethers were achieved. © 2013 Mendeleev Communications. All rights reserved
Detection of sulfate surface-active substances via fluorescent response using new amphiphilic thiacalix[4]arenes bearing cationic headgroups with Eosin Y dye
© 2016 Elsevier B.V.New ammonium-containing derivatives of p-tert-butylthiacalix[4]arene in 1,3-alternate stereoisomeric form were synthesized via copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of corresponding azides with N-propargyl-N,N,N-triethylammonium bromide. Critical aggregation concentration (CAC) of new amphiphilic thiacalixarenes 1-3 (with butyl, octyl and tetradecyl substituents) determined by pyrene micellization method are 91, 59 and 33 μM, respectively. According to DLS data the diameter of these aggregates is around 130 nm. Anionic dye Eosin Y (EY) forms the associates with positive charged thiacalixarenes 1-3, shifts CAC to the low concentration region (2 μM) and decreases nanoaggregates size up to 90 nm. Thiacalixarene/EY associates were investigated as fluorescent probe for the determination of different surface active substances (SAS) in the solution. It was found that only sodium dodecyl sulfate (SDS) and sodium laureth sulfate (SLES) causes EY release, while other anionic, cationic and zwitterionic SAS form only mixed aggregates. Fluorescent response of thiacalixarene/EY associates is considerable from 3.5 μM concentration of SDS
DEVELOPMENT OF ALGORITHM FOR CREATING ATOM-ATOMIC MAPPING USING "NAIVE" BAYES MACHINE LEARNING METHOD
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Unusual reactivity of aliphatic and aromatic amines with bromoalkyl derivatives of thiacalix[4]arene in 1,3-alternate stereoisomeric form
© ISUCT Publishing. For the first time a series of new cationic amphiphilic p-tert-butylthiacalix[4]arene derivatives adopting 1,3-alternate stereoisomeric form was synthesized by quaternization of several tertiary amines and N-heterocycles. The structure of all products was well-defined using modern physical technics. The influence of calixarene and amine sterical hindrances on reactivity is discussed
Development of "structure-property" models in nucleophilic substitution reactions involving azides
© 2014 Pleiades Publishing, Ltd. This paper reports a predictive model for the rate constant of the bimolecular nucleophilic substitution involving the azide moiety. It predicts reaction rate constants in different solvents, including organic mixtures, and with different organic and inorganic azides as reactants. The optimal descriptors describing solvent effects and a cation type in the azide salt were suggested. A reasonably good predictive performance of the model in cross-validation has been demonstrated. The model was applied to predict the rates of the reactions between sodium azide with two conformers of calixarenes as well as 3-bromopropyl phenyl ester. For sterically non-hindered molecules, a good agreement between predicted and experimental reaction rates was observed. On the other hand, the model poorly reproduces the results for sterically hindered molecules
Reconstruction of history of the Tatar Arch in the Neogene-Quaternary time by means of the morphometric analysis
The history of neotectonic development of the Tatar Arch is reconstructed according to the morphometric analysis data. High degree of neotectonic activity of the Southern Dome of the Tatar Arch is shown. Connections between the Tatar Arch morphostructure and its deep structure are traced. The research shows that the majority of local structures (of the second and third order) within the arch are recent formations aged by not more than 106 years old
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