Lyapunov-like Conditions of Forward Invariance and Boundedness for a Class of Unstable Systems

We provide Lyapunov-like characterizations of boundedness and convergence of non-trivial solutions for a class of systems with unstable invariant sets. Examples of systems to which the results may apply include interconnections of stable subsystems with one-dimensional unstable dynamics or critically stable dynamics. Systems of this type arise in problems of nonlinear output regulation, parameter estimation and adaptive control. In addition to providing boundedness and convergence criteria the results allow to derive domains of initial conditions corresponding to solutions leaving a given neighborhood of the origin at least once. In contrast to other works addressing convergence issues in unstable systems, our results require neither input-output characterizations for the stable part nor estimates of convergence rates. The results are illustrated with examples, including the analysis of phase synchronization of neural oscillators with heterogenous coupling

On the birth of limit cycles for non-smooth dynamical systems

The main objective of this work is to develop, via Brower degree theory and regularization theory, a variation of the classical averaging method for detecting limit cycles of certain piecewise continuous dynamical systems. In fact, overall results are presented to ensure the existence of limit cycles of such systems. These results may represent new insights in averaging, in particular its relation with non smooth dynamical systems theory. An application is presented in careful detail

Методологические возможности “Блумингтонской школы”: и перспективы развития современного неоинституционализма

В статье анализируются институциональные процессы формирования научной Блумингтонской школы за последнюю четверть века, которая тесно связана с концептуальным и методологическим наследием Элинор Остром, а также работами ее коллег и учеников. Автор подчеркивает значимость неоинституциональной методологии в современной социологической мысли, в исследованиях социальных дилемм, общих ресурсов, коллективных действий и идентичности. По мнению автора, исследования Блумингтонской школы попытались предложить решение проблемы социально-экономического развития традиционных сообществ в стабильности в условиях социетальной неопределенности, используя неоинституциональную методологию. Дальнейшее методологическое развитие Блумингтонской школы автор связывает с конкретизацией определений социальных дилемм и общих ресурсов, изучением проблем как устойчивости, так и распада институтов, и их трансформации из динамического равновесия с позитивными гнездовыми экстерналиями в девиантное неравновесие. In the article the institutional processes of Bloomington school formation are analyzed. Such processes are closely connected to the conceptual and methodological heritage of Elinor Ostrom and her colleagues and students. The author underlies importance of neo-institutional methodology in the contemporary sociological thought, in studies of social dilemmas, common-pool resources, collective actions and identity. In author’s opinion, by using neo-institutional methodology, studies of the Bloomington school have tried to find a solution of the problem of stable social-economic development of traditional societies. In author’s opinion, the further development of the Bloomington school is connected with further defining social dilemmas and common-pool resources, studies of institutional stability and institutional disintegration and transformations of institutions from dynamic equilibrium with positive nested externalities to dynamic non-equilibrium

Методологические возможности “Блумингтонской школы”: и перспективы развития современного неоинституционализма

В статье анализируются институциональные процессы формирования научной Блумингтонской школы за последнюю четверть века, которая тесно связана с концептуальным и методологическим наследием Элинор Остром, а также работами ее коллег и учеников. Автор подчеркивает значимость неоинституциональной методологии в современной социологической мысли, в исследованиях социальных дилемм, общих ресурсов, коллективных действий и идентичности. По мнению автора, исследования Блумингтонской школы попытались предложить решение проблемы социально-экономического развития традиционных сообществ в стабильности в условиях социетальной неопределенности, используя неоинституциональную методологию. Дальнейшее методологическое развитие Блумингтонской школы автор связывает с конкретизацией определений социальных дилемм и общих ресурсов, изучением проблем как устойчивости, так и распада институтов, и их трансформации из динамического равновесия с позитивными гнездовыми экстерналиями в девиантное неравновесие. In the article the institutional processes of Bloomington school formation are analyzed. Such processes are closely connected to the conceptual and methodological heritage of Elinor Ostrom and her colleagues and students. The author underlies importance of neo-institutional methodology in the contemporary sociological thought, in studies of social dilemmas, common-pool resources, collective actions and identity. In author’s opinion, by using neo-institutional methodology, studies of the Bloomington school have tried to find a solution of the problem of stable social-economic development of traditional societies. In author’s opinion, the further development of the Bloomington school is connected with further defining social dilemmas and common-pool resources, studies of institutional stability and institutional disintegration and transformations of institutions from dynamic equilibrium with positive nested externalities to dynamic non-equilibrium

Production, Physicochemical and Catalytic Properties of Gallium-Containing Zeolite Catalysts

Crystalline galloalumino- and gallosilicates with pentasil structure were synthesised under hydrother-mal conditions. The influence of gallium concentration and binder amount both on physicochemical and catalytic properties of a zeolite in the process of C2-C4 light alkanes aromatization and on catalyst deacti-vation due to carbidization has been studied. Acidic properties of gallium-containing pentasils with differ-ent composition were studied using the method of thermoprogrammed ammonia desorption. The forma-tion of strong aproton acidic sites whose composition includes gallium ions was found. It has been shown that isomorphic aluminium replacement by gallium in the pentasil lattice leads to a significant increase in aromatizing activity and period of stable catalyst operation. A decrease in intensity of coking and the formation of less condensed coke deposits with a wide distribution by the structure are observed with the increase in gallium concentration. The introduction of a binder to galloaluminosilicate results in a signifi-cant increase in mechanical strength of a catalyst. It was established that the most efficient catalyst of the above process is a zeolite containing 2.2% of gallium oxide and 1.3% of aluminium oxide and mixed with 20% of the pseudobeumite. The selectivity of the formation of aromatic hydrocarbons reaches 55-60%, the period of stable operation exceeds 350 h. In accordance with the data obtained suggested are the principles of the selection of efficient catalysts of light alkanes aromatization and optimum conditions of the process

Acidic and Catalytic Properties of Mo-Containing Zeolite Catalysts for Non-Oxidative Methane Conversion

The conversion of methane into benzene, toluene and naphthalene at the reaction temperature of 750 В°C and gas hourly space velocity (GHSV) of 500-1500 h-1 over zeolites modified via impregnation with ammonium heptamolybdate and mechanical mixing with Mo oxide and nanopowder is studied under non-oxidative conditions. It has been established that the highest methane conversion per one run and maximal yield of aromatic hydrocarbons are reached for the sample containing 4.0 mass.% the Mo nanopowder. The stability of Mo-containing zeolite catalysts in the process of methane dehydroaromatization at different GHSV has been studied and a characteristic presence of the induction period caused by the formation of active Mo forms both on the external surface and into the zeolite channels has been established. Both the duration of induction period and stable catalyst operation are decreasing with increasing of GHSV. It was demonstrated that acidic properties of a Mo-containing zeolite catalyst depend on the Mo concentration and method of its introduction

Влияние щелочной обработки на физико-химические и каталитические свойства цеолита типа ZSM‑5 в процессе превращения прямогонной бензиновой фракции нефти

Postsynthetic treatment of a ZSM‑5 type zeolite with aqueous solutions of NaOH of various concentrations is carried out. Structural, acidic, and catalytic properties of the initial zeolite and treated samples are investigated in the course of conversion of straight-run gasoline fraction of oil. The main operational characteristics of the obtained high-octane gasolines are determined. The dynamics of deactivation of the initial ZSM‑5 zeolite and the sample subjected to alkaline treatment is reported and the structure of coke deposits is studied. It is found out that alkaline treatment of zeolites leads to a decrease in their crystallinity, specific surface area and specific mesopore volume, while the average pore diameter increases. Also a decrease in the concentration of acid sites with an increase in their strength is observed. As a result of changes in the properties of zeolites, the performance and stability of the catalysts obtained on their basis increase, which contributes to the improvement of the quality of gasoline formed over these catalysts during the conversion of straight-run gasoline fraction of oilПроведена постсинтетическая обработка цеолита типа ZSM‑5 водными растворами NaOH различной концентрации. Исследованы структурные, кислотные и каталитические свойства исходного цеолита и обработанных образцов в процессе превращения прямогонной бензиновой фракции нефти. Определены основные эксплуатационные характеристики полученных высокооктановых бензинов. Приведена динамика дезактивации исходного цеолита ZSM‑5 и образца, подвергнутого щелочной обработке, изучена структура коксовых отложений. Установлено, что щелочная обработка цеолитов приводит к снижению их кристалличности, величины удельной поверхности и удельного объёма мезопор, увеличению среднего диаметра пор, уменьшению концентрации кислотных центров и увеличению их силы. В результате происходящих изменений свойств цеолитов повышается производительность и стабильность работы катализаторов, полученных на их основе, а также улучшается качество бензинов, образующихся на них в процессе превращения прямогонной бензиновой фракции нефт

Experience in the surgical tactics of complex treatment of victims with severe combined trauma

Relevance. Currently, there is an increase in combined injuries worldwide, with more than a third of the victims of this category dying from various complications in the post-traumatic period.Objective: To determine the possibility of performing optimal surgical interventions in patients with multiple and combined trauma, including anti-shock, with shock of varying duration against the background of intensive therapy.Research material. The paper analyzes the surgical tactics of complex treatment of 150 victims with severe combined trauma. In the course of the study, we divided them into five clinical groups with various shock phenomena. Prediction and determination of the expected duration of shock against the background of intensive therapy was carried out using the table "Score assessment of shockogenicity of trauma" and nomograms developed at the I.I. Janelidze. Research Institute of Emergency Medicine.The results of the work. For clinical and prognostic groups, we noted a correlative relationship between the predicted duration of shock and the time of possible recovery operations, as a result, the coefficient of multiplicity of recovery was revealed. Dividing the average bed-day in hours by the duration of the shock in the forecast groups, we calculated the coefficient of multiplicity "K", which averaged 11 days. K= (144:12 + 184:18 +224:25) : 3 ≈ 11 ( days).Conclusions. Predicting the duration of shock allowed us to develop in an experiment and propose for implementation into clinical practice sparing surgical interventions that are of the nature of anti-shock, as well as to determine the most optimal time for performing reconstructive operations on the principle of simultaneous polysegmental osteosynthesis: 1. Operations for damage to the organs of the upper and lower floors of the abdominal cavity and pelvis. 2. Primary stabilization of fractures of the pelvic bones by an external fixation device in our modification. 3. Fixation of floating rib plastrons by the external fixation device of our modification. 4. Simultaneous polysegmental osteosynthesis

Study of the Impact of Post-Synthetic Treatment on the Physicochemical and Catalytic Properties of Zeolite in the Propane-to-Olefin Transformation Process

Проведено исследование влияния кислотной и термопаровой обработок цеолита типа ZSM‑5 на его структурные, кислотные и каталитические свойства в процессе превращения пропана в олефиновые углеводороды. На основе полученных данных установлено, что кислотная обработка цеолита приводит к повышению его дегидрирующей активности и позволяет снизить температуру проведения процесса. Показано, что проведение предварительной термопаровой обработки цеолитного катализатора оказывает влияние на его структурные характеристики и распределение кислотных центров, приводя к уменьшению силы и концентрации сильных кислотных центров, что способствует увеличению селективности образования олефиновых углеводородов из пропанаA study was carried out of the influence of acid and thermosteam treatments of ZSM‑5 type zeolite on its structural, acid and catalytic properties in the process of converting propane into olefin hydrocarbons. Based on the data obtained, it was established that acid treatment of zeolite leads to an increase in its dehydrogenation activity and allows the temperature of the process to be reduced. It has been shown that preliminary thermosteam treatment of a zeolite catalyst affects its structural characteristics and the distribution of acid sites, leading to a decrease in the strength and concentration of strong acid sites, which helps to increase the selectivity of the formation of olefin hydrocarbons from propan