Substantiation of thermomechanical technology parameters of absorbing levels isolation of the boreholes

The aim of the work is to improve the thermomechanical absorption insulation technology horizons of drilling wells by the established regularities of change and the substantiation of its regime parameters from the composition and physical-mechanical properties strengthen thermoplastic composite material and, on this basis, development a technological regulation containing recommendations on the manufacture of composites and organizations laying work, designing and isolation of the absorption zones of the washing liquid in the drilling rigs wells. The tasks set were solved by complex method research that contains analysis and synthesis of literary and patent sources, conducting analytical, experimental and industrial research. Experimental processing data was carried out using methods of mathematical statistics. Experimental research is carried out using the provisions of the theory of scientific experiment and theory random processes. The evaluation of the effectiveness of the results was carried out in production conditions

Interfacial interactions of hard polyelectrolyte-stabilized luminescent colloids with substrates

© 2015 Elsevier B.V.. The present work introduces an origin of sensing function of polyelectrolyte-coated colloids based on Tb(III) complexes with calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim. The Tb(III)-centered luminescence of the colloids remains unchanged at pH 3-9, although the Tb(III) complexes are highly pH-dependent in DMF solutions. Both colloidal and luminescent properties of the colloids are stable within one month at least, which reveals stability of complex-based hard nanotemplates and soft polyelectrolyte deposition. The chelating substrates (catechol, tetracycline and fluoroquinolone derivatives) induce quick and reproducible luminescent response of the complex-based colloids without any detectable changes of their colloidal properties. The ternary complex formation at the interface of the colloids is the reason for their luminescent response on the substrates in aqueous solutions. Both the insolubility of the Tb(III)-containing cores and the shielding and/or buffer effect of the polyelectrolyte coating affect the interfacial complex formation, which results in more selective luminescent response of the colloids on the tetracycline and fluoroquinolone antibiotics in comparison with the complexes in solutions

Tb(III) complexes with nonyl-substituted calix[4]arenes as building blocks of hydrophilic luminescent mixed polydiacetylene-based aggregates

© 2018 The present work for the first time introduces PDA-based vesicles as convenient supporters of luminescent water insoluble Tb3+ complexes. The specific cyclophanic structure of the ligands, where upper and lower calix[4]arene rims are decorated by nonyl- and chelating groups correspondingly provides both complex formation with Tb3+ ions with the coordination of the latter via two 1,3-diketonate groups and self- or mixed aggregation of the complexes. The conditions of the self-aggregation of the Tb3+ complexes are revealed, although the self-aggregates are unstable being converted into the nanosized precipitates which tend to further aggregation and phase separation. The complexes exhibit Tb(III)-centered luminescence which tends to change in time following the phase separation processes. The embedding of the Tb3+ complexes into the PDA-based vesicles results in the mixed aggregates with significant Tb(III)-centered luminescence and significant colloidal stability. The latter arises from high negative electrokinetic potential values due to exterior carboxylic/carboxylate groups of the PDA vesicles

Structure impact in antenna effect of novel upper rim substituted tetra-1,3-diketone calix[4]arenes on Tb(III) green and Yb(III) NIR-luminescence

© 2016 Elsevier Ltd.Two novel calix[4]arene macrocyclic ligands functionalized with four 1,3-diketone groups at the upper and hydroxyl (3) or propyloxy-groups (6) at the lower rims were synthesized and characterized using NMR, IR spectroscopy, mass spectrometry, and elemental analysis. UV-vis spectrophotometry and ESI mass spectrometry studies indicate 1:1 complex formation of ligands 3 and 6 with Ln(III) (Ln=Tb, Yb) in alkaline DMF solutions resulted from coordination of Ln(III) with 1,3-diketonate groups. Luminescence study of Ln(III) complexes with 3 and 6 reveals significant difference in antenna effects of their deprotonated forms on both Tb(III)- and Yb(III)-centered luminescence. Comparison of ligand-centered emission for ligands 3 and 6 points to the latter as more efficient antenna for Tb(III) and Yb(III). Different conformational behavior of ligands 3 and 6 in alkaline media is assumed as a reason for the experimentally observed difference in sensitization pathways in Ln(III) complexes with 3 and 6

High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones

© The Author(s) 2017.Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[4]arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging

A facile synthetic route to convert Tb(III) complexes of novel tetra-1,3-diketone calix[4]resorcinarene into hydrophilic luminescent colloids

The work presents the synthesis of a novel calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim and its complex formation with Tb(iii) ions in DMF and DMSO solutions. Electrospray ionization mass spectra, 1H NMR, UV-Vis and luminescence spectra indicate a long (three hours at least) equilibration time for the complex formation between the cavitand and Tb(iii) in alkaline DMF and DMSO solutions. These results are explained by the restricted keto-enol conversion, resulting from the steric hindrance effect of the methylenedioxy-groups linking the benzene rings within the cavitand framework. A facile synthetic route to convert luminescent Tb(iii) complexes of various stoichiometries into luminescent hydrophilic colloids is disclosed in this work. The route is based on the reprecipitation of the Tb(iii) complexes from DMF to aqueous solutions with further polyelectrolyte deposition without prior separation of the luminescent complexes. The luminescent colloids exhibit high stability over time and in buffer systems, which is a prerequisite for their applicability in analysis and biolabeling. © the Partner Organisations 2014

Пространственно-временнáя изменчивость снегонакопления на Западном плато Эльбруса (Центральный Кавказ)

Cold glaciers in the middle latitudes are considered unique archives of environmental and climate change. However, alpine ice cores are difficult to interpret, since dynamic changes can occur over very short distances. Detailed radar survey can be used to assess the effect of ice inflow from areas with different conditions of snow accumulation on the surface compared to the drilling point on the isotopic and chemical record in the glacier core. The results of radar studies on the Western plateau of Elbrus (Central Caucasus), located at an altitude of 5100–5150 m above sea level, are presented. A high-frequency ground-based radar survey was carried out in the summer of 2017 to assess the spatial and temporal changes in snow accumulation in the upper (near the top area) part of Elbrus. The ZOND 12-e GPR (ground-penetrating radar, Radar Systems, Inc.) with 500 and 300 MHz shielded antennas was used. The receiving time window was set to 100 ns (500 MHz antenna) and 470 ns (300 MHz) to obtain reflection in the depth range of about 10 m and 50 m, respectively. The results of the GPR sounding are confirmed by data on the stratigraphy, density and chemical composition of the snow-firn thickness from a shallow (24 m) borehole. The density profile made it possible to identify peaks and corresponding ice crusts of 1–2 cm thick that formed during warm periods. The internal reflections, clearly visible on the radar profiles up to 50 m deep, are of isochronous origin and have been interpreted as the boundaries of annual and seasonal layers. Detailed maps of the distribution of snow accumulation covering the cold and warm seasons of 2015–2017 have been obtained. The average thickness of seasonal snow cover on the plateau during this period was equal to 2.07 m, with minimum and maximum values of 0.2 and 3.9 m, respectively. The average values of the water storage in seasonal horizons range from 754 to 1126 mm W.E., while the annual accumulation for the 2015/16 and 2016/17 balance years amounted to 2004 and 1874 mm W.E., respectively. The data obtained were used in 2018 to determine the optimal location for deep core drilling and will further serve as the basis for modeling the age of ice on the Western Plateau of Elbrus.По данным наземного высокочастотного радиозондирования летом 2017 г. на Западном ледниковом плато Эльбруса (Центральный Кавказ) установлено, что аккумуляция снега в привершинной области характеризуется значительной изменчивостью, а также имеет сезонные различия. Анализ полей аккумуляции показал, что в средней части плато снега накапливается меньше, чем в восточной и западной, но распределение снега по площади плато аналогично из года в год. В тёплый период снегонакопление в среднем больше, чем в холодный, и происходит оно более равномерно по площади плато

Violation of the antioxidant system in patients with nasopharyngeal tonsil hypertrophy

Nasopharyngeal tonsil is solitary lymphadenoid formation which is the first in the path of air inhaled in the nose breathing. Adenoid vegetations are accompanied by inflammation in 32.8% of cases. Important role played by the processes of free radical oxidation in the pathogenesis of inflammation. Inflammatory process creates a favorable environment for the development and worsening of lipid peroxidation. The study involved 27 children with nasopharyngeal tonsil hypertrophy degree ll-lll and 14 healthy children aged 1,7-14 years. The study found a correlation between the antioxidant activity of the skin and serum of children with nasopharyngeal tonsil hypertrophy, as well as significant differences between the indices of antioxidant activity in the skin and serum of healthy children and children with nasopharyngeal tonsil hypertrophy.Носоглоточная миндалина - это солитарное лимфаденоидное образование, которое является первым барьером на пути вдыхаемого воздуха при нормальном носовом дыхании. В 32,8% случаев аденоидные вегетации сопровождаются воспалительным процессом. В патогенезе воспаления важную роль играют процессы свободно-радикального окисления. Воспалительный процесс так или иначе создаёт благоприятную обстановку для развития и усугубления процессов перекисного окисления липидов. Проведено обследование 27 детей с гипертрофией носоглоточной миндалины 11-111 степени и 14 здоровых детей в возрасте 1,7-14 лет. В результате исследования выявлена корреляционная связь между антиоксидантной активностью кожи и сыворотки детей с гипертрофией носоглоточной миндалины, а также достоверные различия между показателями антиоксидантной активности кожи и сыворотки у условно здоровых детей и детей с гипертрофией носоглоточной миндалины