Fine Chemical Technologies (E-Journal) / Тонкие химические технологии
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Разработка информационно-моделирующей системы поддержки и принятия решений по управлению безопасностью химических производств
Get PDFThe analysis of the urgency of developing a decision and support information-modeling system for safety in the chemical industry is carried out. The article also covers the main elements of this information-modeling system. Key normative documents backing up the knowledge base of such an information-modeling system are listed below. The algorithm of the safety decision supporting information-modeling system is proposed. A database model of the safety decision supporting information-modeling system is elaborated below. A production rule system is set forth to manage issuing recommendations on the robust decision support information-modeling system in the chemical industry based on a methodological document. An implementation plan is laid out for the robust decision support information-modeling system in chemical industry. It is a ready-made software package based on two-level (client–server) architecture of information systems. This article also contains recommendations based on a test case of a tank equipment total destruction. Results of the computational experiments’ simulation in the TOXI+Risk software corresponding to the test selected values are available.Проведен анализ актуальности разработки информационно-моделирующей системы (ИМС) поддержки и принятия решений по управлению безопасностью химических производств. Приведены основные подсистемы структуры данной ИМС. Перечислены основные нормативные документы для заполнения базы знаний ИМС; предложен алгоритм работы и разработана модель базы данных ИМС. Разработана система продукционных правил для управления выдачи рекомендаций ИМС на основе методического документа. Приведена программная реализация ИМС, представляющая собой готовый комплекс программного обеспечения на основе двухуровневой (клиент–серверной) архитектуры информационных систем. Приведен вывод рекомендаций, полученных для тестового примера аварии полного разрушения резервуарного оборудования. Приведены результаты моделирования вычислительных экспериментов в программном комплексе ТОКСИ+Risk для заполнения тестовой выборки
Разработка реакционно-ректификационного процесса получения окиси мезитила. II. Анализ статики и моделирование процесса
Get PDFUsing the results of an earlier study of the physicochemical properties of the reaction system of the process of producing mesityl oxide, an analysis of the statics of the combined variant of the organization of this process was carried out. It is shown that of practical interest are the modes of the process corresponding to the first specified separation. In this case, the limiting stationary states, characterized by the maximum acetone conversion, selectivity, and the yield of the target product — mesityl oxide, are distinguished. The possibility of practical implementation of the limiting stationary state of the reactive distillation process for producing mesityl oxide, which provides almost complete conversion of acetone with a yield of mesityl oxide approaching 100%, has been proved. The limit stationary state corresponds to the reaction-distillation process with the selection of a single product stream. For the mode of carrying out the combined process that corresponds to the selected limiting stationary state, a schematic flow chart for the production of the target product has been proposed. By means of computational research, it has been established that the most rational option for organizing a reaction hub is to use a single apparatus in it — the reaction-distillation column. In the Aspen Plus® software package, a process model was constructed that corresponded to the proposed technological scheme and through a computational experiment, its structural and parametric optimization was carried out. As a result, the static parameters of the technological system were established, as well as the characteristics of the apparatuses, allowing to obtain the required quality product in the reactiondistillation column. output, approaching 100%. It has been shown that when modeling a chemicaltechnological system, it is necessary to use different sets of parameters of the basic equation used to describe phase equilibrium. Thus, for calculating reactive distillation and distillation columns, the liquid – vapor phase equilibrium parameters for the mesityl oxide–water system should be used, and when calculating the Florentine vessel for this mixture, it is necessary to use the parameters corresponding to the liquid – liquid equilibrium. The use of a single set of parameters of the basic equation leads to significant errors and inadequate description of the process of producing mesityl oxide by condensation of acetone.С использованием результатов выполненного ранее исследования физико-химических свойств реакционной системы процесса получения окиси мезитила проведен анализ статики совмещенного варианта организации указанного процесса. Показано, что практический интерес представляют режимы проведения процесса, соответствующие первому заданному разделению. При этом выделены предельные стационарные состояния, характеризующиеся максимальной конверсией ацетона, селективностью и выходом целевого продукта – окиси мезитила. Доказана возможность практической реализации предельного стационарного состояния реакционно-ректификационного процесса получения окиси мезитила, обеспечивающего практически полную конверсию ацетона с выходом окиси мезитила, приближающимся к 100%. Предельному стационарному состоянию отвечает реакционно-ректификационный процесс с отбором единственного продуктового потока. Для режима проведения совмещенного процесса, отвечающего выделенному предельному стационарному состоянию, предложена принципиальная технологическая схема получения целевого продукта. Путем расчетного исследования установлено, что наиболее рациональным вариантом организации реакционного узла является использование в нем единственного аппарата – реакционно-ректификационной колонны. В программном пакете Aspen Plus® построена модель процесса и посредством вычислительного эксперимента проведена ее структурная и параметрическая оптимизация, в результате которой установлены статические параметры технологической системы, а также характеристики аппаратов, позволяющие получать в реакционно-ректификационной колонне продукт необходимого качества с выходом, приближающимся к 100%. При этом показано, что при моделировании химико-технологической системы необходимо использовать различные наборы параметров базового уравнения, используемого для описания фазового равновесия. Так, для расчета реакционно-ректификационной и ректификационных колонн следует применять параметры фазового равновесия жидкость–пар для системы окись мезитила–вода, а при расчете флорентийского сосуда для указанной смеси необходимо использовать параметры, соответствующие равновесию жидкость–жидкость. Применение же единого набора параметров базового уравнения приводит к существенным погрешностям и неадекватному описанию процесса получения окиси мезитила посредством конденсации ацетона
ФУНКЦИОНАЛЬНОЕ МОДЕЛИРОВАНИЕ УПРАВЛЕНИЯ СИНТЕЗОМ УГЛЕРОДНЫХ СОРБЕНТОВ
Get PDFThe formalized model of carbon sorbent synthesis control based on the methodology for functional modeling is constructed. The correlations between the directions of use and the properties of carbon sorbents are revealed. The characteristics that are essential regardless of the direction of use of the sorbent, in particular, sorption properties and strength are identified. The technologies based on the gas-phase method of obtaining carbon material are considered, the analysis of individual stages of the process of obtaining carbon sorbents is carried out. The analysis of the influence of the technological parameters of the synthesis on the properties of sorbents is carried out. On the basis of the established relationships, a functional model has been built that provides a hierarchically ordered, structured, visual description of the management of carbon sorbent synthesis. The simulation is performed “from top to bottom” from the most general description to the detail. The resulting model is a set of interrelated graphical diagrams. At the initial stage, the synthesis of carbon sorbent is considered as a single process, the input parameters of which are hydrocarbon gas, the activating agent and the material form factor, the output - carbon sorbent, and the control parameters are the requirements for strength and sorption properties. Then the synthesis process is decomposed. The control processes (analysis of raw material properties and matrix selection), technological processes (raw material preparation) and mixed processes are distinguished as a result of decomposition. The model includes a consistent description of the technological parameters selection (temperature, gas flow and time) for both stages of the synthesis process. The model is the base for information support providing for the production of carbon sorbents with the required properties
Рибавирин и его аналоги: можно ли старую собаку научить новым фокусам?
Get PDFThe review article focuses on the current state of synthetic and biological studies of ribavirin analogs. Ribavirin is a broad-spectrum nucleoside antiviral drug with a 50-year long history of research and application, but its mechanism of action still remains unclear. This article examines contemporary views on the antiviral and antitumor effects of ribavirin and its analogs and describes the contradictions and gaps that exist in our knowledge. In recent years, new nucleoside analogs of ribavirin have been synthesized. These ribavirin derivatives modified at the heterocyclic base, have the potential to become the antiviral and antitumor agents of the new generation. Thus, this paper presents a systematic review of antiviral activities, antitumor activities and structure–activity relationship (SAR) correlations of 39 ribavirin analogs created in the past 15 years. Biological targets and possible mechanisms of action of these new compounds are also discussed, as well as the prospects and possible directions for further research.Обзор посвящен современному состоянию синтетических и биологических исследований аналогов рибавирина. Рибавирин – нуклеозидный противовирусный препарат широкого спектра действия с 50-ти-летней историей исследований и применения, но механизмы его действия до сих пор остаются неясными. В обзоре кратко изложены современные взгляды на биологические механизмы противовирусного и противоопухолевого действия рибавирина и его аналогов, существующие в этих взглядах противоречия и пробелы. В течение последних лет получены новые нуклеозидные аналоги – производные рибавирина по гетероциклическому основанию, потенциально представляющие собой противовирусные и противоопухолевые средства нового поколения. В статье дан систематический обзор исследований противовирусной и противоопухолевой активности и корреляций «структура – активность», в общей сложности, для 39 аналогов рибавирина, представленных за последние 15 лет, обсуждаются биологические мишени и возможные механизмы действия этих новых соединений, а также перспективы и направление дальнейших исследований
ПРОИЗВОДСТВО ЭТАНОЛА ИЗ КОЛОКАЗИИ (Xanthosoma sagittifolium): ПРИМЕНЕНИЕ ТЕРМОДИНАМИКО-ТОПОЛОГИЧЕСКОГО АНАЛИЗА
Get PDFCocoyam (Xanthosoma sagittifolium (L.) Schott) is a tropical plant of the family of Araceas. Nigeria, China and Ghana are the countries that currently own most of the world production of this plant. In Colombia, there are not extensive crops of this plant, but it is used for animal feeding mainly. The plant has an aerial part with a high content of protein (leaves) and a tuber with an average starch content about 25% w/w. Compared to others starchy raw materials, this is a high value. Due to this fact this first-generation starchy material could be considered as a possible feedstock for the production of ethanol. Process design must ensure that the most advanced concepts are applied at the design and processing stage for every raw material to ensure efficient and more sustainable processes. For this reason, thermodynamic-topological analysis was used for the design of the stage of the produced ethanol purification. This work presents the process of ethanol production using cocoyam tuber. The software Aspen Plus v8.6 (Aspen Technology, Inc., USA) was used for the techno-economic assessment, and the Waste Reduction Algorithm (WAR) of the Environmental Protection Agency of the EE.UU. (EPA) was used to measure the environmental performance. The obtained production cost was 1,6 USD per kilogram, and the environmental impact was very low. This is an excellent incentive to promote the application of this feedstock to obtain a feasible alternative for the production of ethanol. Additionally, the use of thermodynamic-topological analysis in the design stage of the purification stage of the process proved to be very useful and easily applied
ИНФОРМАЦИОННАЯ СИСТЕМА ТИПОВОЙ ИСПЫТАТЕЛЬНОЙ ЛАБОРАТОРИИ РАДИАЦИОННОГО КОНТРОЛЯ
Get PDFDevelopment of information-analytical system of radiation control is based on existing methods and hardware-software measuring instruments for the purpose of systematizing, storing and processing the results of analysis of samples of various composition and origin. Studying a large flow of environmental and technological samples includes the most difficult task to ensure the required accuracy of calculation of activities and errors, especially at low activities levels at the threshold of detectable area. The information system hardware includes a set of devices designed to measure the activity of the samples, and a local computer network. The server part of the software package includes a client-server database management system and a web application for database administration. In addition to the standard programs included in the delivery of radiometric equipment the client part of the software package includes the program "ODRA", developed using object-oriented language C# in Microsoft Visual Studio. The program "ODRA" includes modules for calculating the specific (volumetric) activity of radionuclides in low-active samples of materials and environmental objects, as well as for calculating the relative and absolute error of activity determination. The program has a convenient graphical user interface for database communication. The information system of the radiation testing laboratory of the enterprise that conducts work with radioactive materials has undergone a four-year approbation in the experimental production mode at VNIIHT in 2014-2017 and can significantly reduce the processing time of the results of determining the radioactivity of technological and environmental samples and reduce the operator error factor
ОКИСЛЕНИЕ ДИСПЕРСНЫХ УГЛЕРОДНЫХ МАТЕРИАЛОВ
Get PDFIt is proposed to consider the process of carbon materials oxidative activation from the positions of topochemical reactions involving chemisorption of the activating agent (oxidizer) on the material surface active centers followed by chemical interaction. Such an approach makes it possible to control the process of creating a carbon material with the desired characteristics of the porous space. It is assumed that the oxidizer chemisorption active centers are amorphous carbon, which is localized on the material crystallites boundaries. The change in the length of these boundaries will lead to a change in the process rate. It is shown that the number of such active centers on the carbon material surface depends on the size of the crystallites. It will have a significant impact not only on the rate of activation, but also on the possibility of the process flow on the surface or with porosity formation. Mathematical models describing the carbon sample specific surface changing in the oxidation process are proposed. They allow quantifying the proportion of carbon that is oxidized on the sample surface or with pores formation, as well as quantifying the number of pores. It is shown that the ratio of pore formation and surface oxidation processes depends on the oxidation temperature, the oxidizer nature and its flow rate. The proportion of porosity formation decreases with the increase in the oxidant flow rate and the increase in temperature. It was experimentally shown that in order to obtain a material with a more developed porous space and a high specific surface it is preferable to use carbon dioxide as an oxidizing agent
ТЕРМИЧЕСКАЯ СТАБИЛЬНОСТЬ ПОЛИМЕРНЫХ КАБЕЛЬНЫХ КОМПОЗИЦИЙ С НАПОЛНИТЕЛЕМ-АНТИПИРЕНОМ
Get PDFCurrently, halogen-free cable compositions are becoming increasingly common in the manufacture of cable compositions. The concept of halogen-free or “zero halogen” becomes a symbol of fire resistance, low-smoke characteristics, low toxicity of volatile products of combustion, the absence of the toxic, corrosive and irritating gas - hydrogen chloride - and other hydrogen halides in the volatile products. More and more manufacturers of cable products are beginning to pay increasing attention to the problems of processing, toxicity and fire safety. It should be noted that the requirements for improving the fire safety of cable products are constantly becoming tougher, since the main problem of most of these polymeric materials is their flammability, high smoke generation and high flame spread rate. In this regard, there is a burning question to increase these characteristics and bring them to the level of compounds based on PVC. The main way to increase the flame-retardant characteristics of halogenfree cable compositions is to introduce mineral fire retardants into these compositions. The study of the composition and packaging of these mineral fillers-flame retardants makes it possible to increase the level of flame-retardant characteristics of halogen-free cable compositions. The paper presents the results of studies on the thermal stability of cable compositions based on PE + EVA mixtures containing magnesium hydroxide crystalline hydrate as a filler-flame retardant. It is shown that cable compositions containing magnesium hydroxide crystal hydrate are characterized by higher heat resistance and thermal stability (~ 2-fold) compared to a polymeric matrix based on PE + SEVA. This allows to process them at high temperatures (more than 200°C) by extrusion and pressure casting
СИНТЕЗ И СРАВНЕНИЕ СВОЙСТВ МЕТАЛЛОКОМПЛЕКСОВ МЕЗО-АРИЛЗАМЕЩЕННЫХ ПОРФИРИНОВ КАК ПОТЕНЦИАЛЬНЫХ КРАСИТЕЛЕЙ ДЛЯ СОЛНЕЧНЫХ ЯЧЕЕК
Get PDFThis work is dedicated to the synthesis of porphyrin metal complexes for creation of dyesensitized solar cells (DSSC). Three different dyes were synthesized - zinc complexes of porphyrins containing alkoxyl substituents: with symmetric structure (Zn-P1), as well as asymmetric (type A3B) with the introduction of a donor (Zn-P2) or an acceptor (Zn-P3) substituents via the 1,3,5-triazine fragment. The spectral characteristics of the synthesized substances are compared. For all the obtained dyes, geometry optimization and visualization of the electron density distribution were carried out using computational methods based on the density functional theory (DFT). The location of the frontier unbound molecular orbitals is more optimal when an acceptor substituent containing anchor groups is introduced via the triazine moiety. However, the use of ligands containing an anchor group simplifies the synthesis of the dye and opens up more possibilities for varying both the ligand and the introduced donor substituents. As a result, it was concluded that the spatial distribution of the dye, when applied to the electrode and, consequently, the number of its molecules per unit area of the semiconductor, can have the greatest effect on the efficiency of a cell using t he described compounds
ИНФОРМАЦИОННО-АЛГОРИТМИЧЕСКАЯ ПОДДЕРЖКА РАЗРАБОТКИ ТВЕРДЫХ ЛЕКАРСТВЕННЫХ ФОРМ
Get PDFThe article deals with the application of the system approach for constructing informationalgorithmic support for the pharmaceutical development of solid dosage forms. Information modeling of the life cycle of pharmaceutical drug development has been carried out starting from the stage of studying the active pharmaceutical substance and ending with the utilization of the drug. These models are built in the IDEF0 nomination. A generalized block diagram is presented that reflects, in its most general form, the iterative process of developing a ready-made dosage form as applied to the further transfer of technology. The basis of the system approach is QbD - "Quality planned in the development". To implement the QbD principle on the basis of the system approach, systemic set-theoretic models of information support of pharmaceutical development in the nomenclature of Melentiev have been constructed. A model for controlling the pressing process is also provided, which takes into account all the technological stages in the development of a solid dosage form. Functional models in the IDEF0 nomenclature of the technological process are constructed from the preparation of premises, personnel and components of the dosage form to the stage of packing and packaging of the finished dosage form. The construction of an informational intellectual control system for pharmaceutical development has been considered in detail with particular attention paid to the construction of a database of medicinal and auxiliary substances using the example of solid dosage forms. In Melentiev's bracket notation, the database of auxiliary substances necessary for the design of a solid dosage form is filled. The "Entity-relationship" model and the relational model for the database of medicinal and auxiliary substances have been construct