Mathematical model of stacked one-sided arrangement of the burners

Paper is aimed at computer simulation of the turbulent methane-air combustion in upgraded U-shaped boiler unit. To reduce the temperature in the flame and hence NOx release every burner output was reduced, but the number of the burners was increased. The subject of studying: complex of characteristics with space-time fields in the upgraded steam boiler E-370 with natural circulation. The flare structure, temperature and concentrations were determined computationally

ПОЛИ-4-ВИНИЛПИРИДИНИЕВЫЕ НАНОГУБКИ В КАЧЕСТВЕ МОДИФИКАТОРОВ ЭЛЕКТРОФОРЕТИЧЕСКИХ СИСТЕМ ДЛЯ РАЗДЕЛЕНИЯ ЗАРЯЖЕННЫХ АНАЛИТОВ

Novel hydrophilic ionic polymer nanoparticles based on the N-alkylated hypercrosslinked poly-4-vinylpyridine (nanosponges ‒ NS) have porous structure, pH-independent positive charge and contain the aromatic rings. These nanosponges have not yet been studied in the capillary electrophoresis mode, but their characteristics suggest the possibility of creating the fused silica capillary walls coating for the separation of anionic and cationic analytes. In the current research, the authors, for the first time, have proposed the approaches to the formation of coatings based on the nanosponges with a molecular weight of 400 and 10 kDa. It was established that the stability of such coatings could be achieved by the introduction of NS into the background electrolyte. The pH range of background electrolytes for the subsequent electrophoretic experiments was determined to be from 4 to 9. The NS-based coatings were compared with the previously investigated coatings based on the crosslinked polystyrene nanoparticles (NPs), functionalized with the quaternary ammonium groups. Capillaries modified with NS (400 kDa) were tested for the electrophoretic separations of wide range of analytes: carboxylic acids, aminoacids, fluoroquinoline antibiotics, biogenic amines, and proteins. The separation selectivity of carboxylic acids on the NS-modified capillaries was different from the separation selectivity on the capillaries modified with NPs, functionalized with quaternary ammonium groups. NS affect the separation selectivity of aminoacids by interacting with these analytes, while for fluoroquinoline antibiotics NS act as an agent generating the reversed electroosmotic flow (EOF). The modification of fused silica capillary walls by NS with molecular mass of 400 kDa prevented the sorption of biogeniс amines and lyzocyme protein during their electrophoretic separation.Keywords: capillary electrophoresis, nanoparticles, coatings of fused silica capillary wallsDOI: http://dx.doi.org/10.15826/analitika.2019.23.2.006(Russian)D.A. Polikarpova1, D.V. Makeeva1, L.A. Kartsova1, V.A. Davankov2, L.A. Pavlova2 1Saint-Petersburg State University, Institute of Chemistry,Universitetskii pr. 26., St. Petersburg, Petergof, 198504, Russian Federation2A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, Moscow, 119334, Russian FederationНовые гидрофильные ионные полимерные наночастицы на основе N-алкилированного сверхсшитого поли-4-винилпиридина (наногубки – НГ)  имеют пористую структуру, несут рН-независимый положительный заряд и содержат ароматические звенья, что позволяет предполагать возможность формирования покрытий стенок кварцевого капилляра на их основе для разделения анионных и катионных аналитов. В рамках исследования впервые предложены подходы к формированию покрытий на основе наногубок с молекулярной массой 400 и 10  кДа. Показано, что для обеспечения стабильности таких покрытий необходимо введение НГ в состав фонового электролита (ФЭ). Определен рабочий диапазон рН ФЭ (4-9) для последующих электрофоретических экспериментов. Результаты сопоставлены с полученными нами ранее экспериментальными данными по формированию покрытий на основе наноразмерных частиц (НЧ) сшитого полистирола, функционализированных четвертичными аммонийными группами. Для выявления перспектив покрытия на основе НГ с молекулярной массой 400 кДа рассмотрен широкий спектр аналитов: карбоновые кислоты, аминокислоты, антибиотики фторхинолонового ряда, биогенные амины, белки. Разделение карбоновых кислот на таких капиллярах характеризуется иной селективностью по сравнению с капиллярами, покрытыми НЧ, функционализированными четвертичными аммонийными группами. При разделении аминокислот НГ влияют на селективность разделения за счет взаимодействия с аналитами, а в случае антибиотиков НГ выступают только в роли агента, обращающего электроосмотический поток (ЭОП). Установлено, что модификация стенок капилляра НГ с молекулярной массой 400 кДа позволяет предотвращать сорбцию основных аналитов (биогенные амины, белок лизоцим) в процессе их электрофоретического разделения.Ключевые слова: капиллярный электрофорез, наночастицы, покрытия стенок капилляраDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.00

Biological Homochirality on the Earth, or in the Universe? A Selective Review

The discovery of meteoritic alpha-amino acids with significant enantiomeric excesses of the L-form has suggested that some cosmic factors could serve as the initial source for chiral imbalance of organic compounds delivered to the early Earth. The paper reviews major hypothesis considering the influence of chiral irradiation and chiral combinations of physical fields on the possible ways asymmetric synthesis and transformations of organics could take place within the solar system. They could result in a small enantiomeric imbalance of some groups of compounds. More attention is paid to the hypothesis on parity violation of weak interaction that was supposed to cause homochirality of all primary particles and a more significant homochirality of compounds directly synthesized from the latter in a plasma reactor. The first experiment with material synthesized in a plasma torch resulting from a super-high-velocity impact showed formation of alanine with the excess of L-form between 7 and 25%. The supposed conclusion is that L-amino acids could serve as a starting homochiral biomolecular pool for life to emerge all over the Universe

Critical review on the origin of atmospheric oxygen: Where is organic matter?

In a short note of 1998 Davankov questioned the generally accepted notion that the unique features of the planet Earth, namely, the presence of life and atmospheric oxygen are inseparably bonded as a case and effect. Indeed, photosynthesis in terrestrial and aquatic phototrophs simultaneously produces oxygen and carbohydrates in almost equal amounts. Since the degradation of organic matter through burning or rotting also consumes an equivalent amount of oxygen, the total masses of oxygen and organic material must always remain comparable. This correlation for Earth appears to be drastically distorted in favor of oxygen, thus disproving the still widespread delusion of biogenic origin of atmospheric oxygen. Instead, by analyzing more recent data on the balance between oxygen and organics we arrive at the conclusion that radiolysis of water vapors with the preferential dissipation of hydrogen to space, most probably, was the major source of the free and oxidation-spent oxygen. The present review tries to illuminate the most important uncertainties that still remain to be clarified before an interdisciplinary and scientifically-balanced picture on the evolution of Earth gets settled