Simple methodological approach for assessing microbial mineralization rates in an aqueous anaerobic medium

The aim of this study was to propose and discuss a simple manometric method to quantify the emission rates of gases resulting from the microbial anaerobic mineralization of organic resources, as leaves, thin branches, and macrophyte detritus. The proposed method can be used under laboratory conditions. The method consists of using a water pressure gauge attached to the reaction flask. The incubations were prepared with samples of water from Paranapanema River and Typha domingensis, the experiment lasted 9.8 months. The procedures for preparing the incubations are presented in detail, as well as the calculations for the conversion of the volumetric measurement into carbon mass (i.e., daily rate of carbon gas emissions). According to the results obtained from T. domingensis mineralization assays it was possible to demonstrate that, numerous events related to mineralization could be adequately addressed (e.g., the heterogeneous detritus composition). The results of this method were quite convergent with those obtained in kinetic experiments (used as a reference) after the 30th mineralization day, suggesting the use of this method mainly for medium- and long-term experiments. As exemplified by T. domingensis incubations, this method is particularly valuable for the systemic comparison of the several organic resources mineralization and for the primary measurement of the main parameters involved (e.g., reaction rates constants). This method combined with other short-term experiments can greatly improve the understanding of the cycling of organic resources in aquatic environments.

Peculiarities of change in number and composition of winter wheat rhizosphere microbiome in the process of ontogenesis

In agroecosystems, microorganisms are the main factor in the soil formation process, plant nutrition and phytosanitary condition of the soil. Therefore, all measures aimed at restoring soil fertility and increasing productivity, environmental safety of agricultural production are closely linked to the activities of microorganisms. Increased local activity, biomass and diversity of microbiota are one of the most important characteristics that distinguish the rhizosphere from the total soil volume. The aim of the research was to study the number and composition of the microbial complex of the rhizosphere of cereals (winter wheat of different varieties of domestic selection) in the process of ontogenesis. To conduct a set of microbiological studies, soil samples were taken and prepared (typical chernozem) in compliance with the standard requirements for sample preparation and storage of samples in the laboratory. The analysis of rhizosphere soil samples was performed according to the variants of different varieties of winter wheat of domestic selection. The number of soil microorganisms was determined by the method of inoculation of suspensions on nutrient media according to generally accepted methods in microbiology. Determination of the total microbial biomass in the soil was carried out by the rehydration method, and the intensity of "respiration" of the soil, respectively, by the release of CO2 and O2 absorption by the manometric method (Warburg apparatus). It is established that varietal specificity is significantly related to the peculiarities of microbiome formation in different phases of plant growth and development, which is an integral indicator of functional and metabolic activity of soil microorganisms. The number and composition of the microbial complex of winter wheat rhizosphere in the process of ontogenesis changes significantly, especially in the ratio of the number of spore-forming and non-spore forms of microorganisms under the same conditions of crop cultivation. The total pool of saprotrophic microorganisms of the rhizosphere demonstrates the variability of biomass and changes in favor of ecoplastic Bacillus. An increase in the number of spore-forming bacteria to 4.2 x 107 CFU/g in the variants of growing certain varieties was found. It is shown that in the cultivation of different varieties of winter wheat there are stable indicators of the intensity of CO2 emissions - from 5.2 to 7.0. A similar trend can be traced to the absorption of O2 (not more than 5.3-6.8).

RESEARCH OF SENSORY CHARACTERISTICS OF POULTRY MEAT OBTAINED USING VARIOUS METHODS OF STUN

Исследованы цветовые и ароматические характеристики мяса бройлеров, полученного оглушением птицы углекислым газом и электрическим способом. Объектом исследования были образцы мяса бройлеров, произведенного в Казахстане электрооглушением – образец 1; и в РФ: газовым оглушением – образец 2; электрооглушением – образец 3. Каждый из образцов был представлен мясом из 2 частей тушки: бедра и грудки. Образцы мяса сканировали в цветовом режиме TrueCоlоr, оптическое разрешение 300 dpi, размер не менее 500 ґ 500 pix. Цифровое изображение обрабатывали с помощью программы ImаgeJ 1.46. Численные характеристики окраски исследованных образцов мяса птицы определяли сканерометрическим методом с использованием планшетного сканера. Изображения обрабатывали на компьютере в режиме RGB. Исследование запаха мяса проводили на анализаторе запахов МАГ-8 по методике «электронный нос» в режиме фронтальной подачи пробы и инжекторного ввода равновесной газовой фазы над исследуемым материалом. В качестве измерительного массива применяли набор из 8 сенсоров с наибольшей чувствительностью к различным классам легколетучих органических соединений. Установлено, что цветометрические характеристики образцов мяса, полученного разными способами оглушения птицы, идентичны. Различия в качественном и количественном составе аромата образца мяса 2, полученного оглушением птицы в газовой среде, и образца мяса 3, полученного электрооглушением птицы, составляют от 2 до 10%, что не позволяет говорить о существенном изменении в составе легколетучих соединений, выделяющихся из мяса. Сенсорные характеристики исследованных образцов мяса, полученного разными способами оглушения птицы, практически идентичны. Это доказывает возможность применения более эффективной технологии газового оглушения. The color and aroma characteristics of broiler meat obtained by stunning poultry with carbon dioxide and electric method were studied. Samples of broiler meat produced in Kazakhstan by electric deafening – sample 1; in the Russian Federation: gas deafening – sample 2; electric deafening – sample 3 were the object of research. Each of the samples was represented by meat from 2 parts of the carcass: thighs and breasts. Meat samples were scanned in TrueColor color mode, with an optical resolution of 300 dpi and a size of at least 500 ґ 500 pix. The digital image was processed using ImageJ 1.46. Numerical characteristics of the color of the studied samples of poultry meat were determined by the manometric method using a flatbed scanner. Images were processed on a computer in RGB mode. The study of the smell of meat was carried out on the MAG-8 smell analyzer using the "electronic nose" method in the mode of frontal sample delivery and injection of the equilibrium gas phase over the test material. A set of 8 sensors. the most sensitive to various classes of volatile organic compounds were used as a measuring array. It was found that the colorometric characteristics of meat samples obtained by different methods of stun poultry are identical. Differences in the qualitative and quantitative composition of the flavor of meat sample 2, obtained by stun poultry in a gas environment, and meat sample 3, obtained by electric stun poultry, are from 2 to 10%, which does not allow us to talk about a significant change in the composition of low-volatile compounds released from the meat, The sensory characteristics of the studied meat samples obtained by different methods of stun poultry are almost identical. This proves the possibility of using more effective gas stun technology.

Kinetics and Mechanism of Thermal Decomposition of 1-R-Substituted bis(1,1-Dinitromethyl-3-Nitro- 1,2,4-Triazole-5-yl)

Thermal decomposition kinetics of 1-substituted bis(1,1-dinitromethyl-3-Nitro-1,2,4-triazole- 5-yl) in solution of 1,3-dinitrobenzene is studied with manometric method under isothermal conditions. The limiting stage of thermal decomposition is homolytic break of C-NO2 bond in gem-dinitromethyl group; activation parameters of this stage are calculated. The reactivity of investigated compounds is analyzed. Correlation dependences between logarithm of rate constant, activation energy and steric constant of substituent R are obtained

T-x-диаграмма системы Ga – Se в диапазоне составов 48.0 – 61.5 мол. % Se по данным термического анализа

Целью настоящей работы было термографическое исследование T-x диаграммы системы Ga – Se в диапазоне температур от 500 до 1100 °С и в диапазоне составов от 48.0 до 61.5 mol % Se. Методом исследования являлся дифференциальный термический анализ c компьютерной регистрацией данных. Получены свидетельства о наличии ретроградного солидуса фазы g-GaSe со стороны селена (с областью гомогенности в несколько десятых mol % при температурах выше эвтектической) и о независимом существовании близких по составу фаз e-GaSe и g-GaSe. При этом более богатая галлием фаза e-GaSe испытывает перитектический распад с образованием расплава (L2) и g-GaSe. Для темпера-туры предполагаемой перитектической реакции получено значение 921 ±2 °С. Вместе стем, на данном этапе работ не получено никаких данных в пользу существования ожидавшейся (по аналогии с системой Ga – S) высокотемпературной модификации, близкой по составу к сесквиселениду галлия (Ga2S3). Другие результаты, полученные в настоящей работе (характер и температуры плавления промежуточных фаз, температуры эвтектического и монотектического превращений, а также координата эвтектического состава), хорошо согласуются с литературными данными по исследованной системе ЛИТЕРАТУРА1. Kainzbauer P., Richter K. W., Ipser H. The binary Bi-Rh phase diagram: stable and metastable phases //J. Phase Equilibria and Diffusion, 2018, v. 39(1), pp. 17– 34. DOI: https://doi.org/10.1007/s11669-017-0600-52. Dolyniuk J.-A., Kaseman D. C., Sen S., Zhao J., Osterloh F. E., Kovnir K. mP-BaP3: A new phase froman old binary system // Chem. Eur. J., 2014, v. 20, pp. 10829–10837, DOI: https://doi.org/10.1002/chem.2013050783. Березин С. С., Завражнов А. Ю., Наумов А. В., Некрылов И. Н., Брежнев Н. Ю. Фазовая диаграммасистемы Ga–S в области 48.0–60.7 мол. % S // Конденсированные среды и межфазные границы, 2017,т. 19(3), с. 321–335. DOI: https://doi.org/10.17308/kcmf.2017.19/2084. Волков В. В., Сидей В. И., Наумов А. В., Некрылов И. Н., Брежнев Н. Ю., Малыгина Е. Н., Завражнов А. Ю. Высокотемпературная кубическая модификация сульфида галлия (Xs = 59 мол. %) и Т, х-диаграмма системы Ga – S // Конденсированные среды и межфазные границы, 2019, т. 21(1), с. 37–50.DOI: https://doi.org/10.17308/kcmf.2019.21/7155. Zavrazhnov A., Berezin S., Kosyakov A., Naumov A., Berezina M., Brezhnev N. J. The phase diagramof the Ga–S system in the concentration range of 48.0–60.7 mol % S // Thermal Analysis and Calorimetry,2018, v. 134(1), pp. 483–492. DOI: https://doi.org/10.1007/s10973-018-7124-z6. Okamoto H. Ga–Se (Gallium-Selenium) // J. Phase Equilibria and Diffusion, 2009, v. 30, p. 658. DOI:https://doi.org/10.1007/s11669-009-9601-37. Dieleman J., Sanders F. H. M. Phase diagram of the Ga-Se system // Phillips J. Res., 1982, v. 37(4),pp. 204 – 229.8. Zavrazhnov A. Yu. Turchen D. N., Goncharov Eu. G., Zlomanov V. P. Manometric method for thestudy of P-T-x diagrams // J. Phase Equilibria and Diffusion, 2001, v. 22(4), pp. 482–490. DOI: https://doi.org/10.1361/1054971017703330639. Shtanov V. I, Komov A. A, Tamm M. E., Atrashenko D. V., Zlomanov V. P. Gallium-selenium systemphase diagram and photoluminescence spectra of GaSe crystals // Doklady Akademii nauk SSSR, 1998, v. 361(3),pp. 357–361. (in Russ.)10. Glazov V. M., Pavlova L. M. Semiconductor and metal binary systems. Phase equilibria and chemicalthermodynamics. Springer, 1989, 327 p. DOI: https://doi.org/10.1007/978-1-4684-1680-011. Ider M. Pankajavalli R., Zhuang W. Thermochemistry of the Ga–Se System. J. Solid State Scienceand Techn., 2015, v. 4(5), Q51–Q60 DOI: https://doi.org/10.1149/2.0011507jss12. Zavrazhnov A., Naumov A., Sidey V., Pervov V. Composition control of low-volatile solids throughchemical vapor transport reactions. III. The example of gallium monoselenide: Control of the polytypicstructure, non-stoichiometry and properties // Thermochimica Acta, 2012, v. 527, pp. 118–124. DOI:https://doi.org/10.1016/j.tca.2011.10.012

Quantitative Measurement System of Liquid Products in Sealed Tank

Many industries apply pressure tanks for the storage of various types of liquids [1]. It can be toxic, chemically active liquids or food products. Storage conditions of these liquids can have a wide range of pressures and temperatures; therefore it is preferable to control the liquids levels from the outside of the tank. The most optimal solution in this case is the ultrasonic pulse time method [2-6], which is also widely used in robotics [7], fishing, shipping [8-9], archeology [10-11], non-destructive testing [12-17] and manometric method [18].

Manometric Real-Time Studies of the Mechanochemical Synthesis of Zeolitic Imidazolate Frameworks

We demonstrate a method for real-time monitoring of mechanochemical synthesis of metal-organic frameworks, by measuring changes in pressure of gas produced in the reaction. Using this manometric method to monitor the mechanosynthesis of the zeolitic imidazolate framework ZIF-8 from basic zinc carbonate reveals an intriguing feedback mechanism in which the initially formed ZIF-8 reacts with the CO₂ byproduct to produce a complex metal carbonate phase, the structure of which is determined from powder X-ray diffraction data. Formation of the carbonate phase may be prevented by using excess ligand, leading to quantitative formation of ZIF-8. This reaction was performed on a 90 g scale, with the excess ligand removed by sublimation.