PECULIARITIES OF THE DEVELOPMENT AND IMPLEMENTATION OF AVIATION BIOFUELS IN UKRAINE

The modern environmental problems caused by the activity of aviation industry are figured out in the article. The main tendencies for transition to alternative jet fuels all over the world are described. Attention is paid to the policies of developed countries intended to the implementation of biofuels in aviation, and introduction of new standards for alternative jet fuels quality. Contemporary state of jet fuels production and use in Ukraine is discussed. Ukrainian experience in development of national policy for introduction of alternative jet fuels into civil aviation is described. The current problems, which are the barriers nowadays for jet biofuels implementation in Ukraine are presented in details. At the same time benefits that will be achieved in a result of biofuels application are emphasized.В статье рассмотрено современные экологические проблемы, которые связаны с деятельностью авиационной отрасли. Представлено основные мировые тенденции относительно перехода на альтернативные авиционные топлива. Уделено внимание политике развитых стран мира, которая направлена на внедрение биотоплив в авиацию, а также введению новых стандартов относительно качества авиационных топлив. В статье рассмотрено современное состояние производства и потребления топлив для воздушно-реактивных двигателей в Украине. Представлено опыт Украины в разработке национальной политики по внедрению альтернативных авиационных топлив в гражданскую авиацию. В статье детально раскрыто современные проблемы, которые на сегодняшний день являются преградой для внедрения альтернативных авиационных топлив в Украине. В тоже время акцентиовано внимание на преимуществах, которые будут достигнуты в результате применения биотоплив.У статті розглянуто сучасні екологічні проблеми, пов’язані з діяльністю авіаційної галузі. Описано основні світові тенденції щодо переходу на альтернативні авіаційні палива. Приділено увагу політиці розвинених країн світу, що спрямована на впровадження біопалив у авіацію, а також введенню нових стандартів щодо якості авіаційних палив. У статті висвітлено сучасний стан виробництва та споживання палив для повітряно-реактивних двигунів в Україні. Представлено досвід України у розробленні національної політики щодо впровадження альтернативних авіаційних палив у цивільну авіацію. У статті детально розкрито сучасні проблеми, що на даний час є перепоною до впровадження альтернативних авіаційних палив в Україні. В той же час наголошено на перевагах, що будуть досягнуті у майбутньому у результаті застосування біопалив

SYNTHESIS OF CYCLOPROPA[C]COUMARINS FROM DONOR-ACCEPTOR CYCLOPROPANES

This work was supported by the Ministry of Education and Science of the Russian Federation (grant MK1567.2018.3)

Statistical properties of Lorenz like flows, recent developments and perspectives

We comment on mathematical results about the statistical behavior of Lorenz equations an its attractor, and more generally to the class of singular hyperbolic systems. The mathematical theory of such kind of systems turned out to be surprisingly difficult. It is remarkable that a rigorous proof of the existence of the Lorenz attractor was presented only around the year 2000 with a computer assisted proof together with an extension of the hyperbolic theory developed to encompass attractors robustly containing equilibria. We present some of the main results on the statisitcal behavior of such systems. We show that for attractors of three-dimensional flows, robust chaotic behavior is equivalent to the existence of certain hyperbolic structures, known as singular-hyperbolicity. These structures, in turn, are associated to the existence of physical measures: \emph{in low dimensions, robust chaotic behavior for flows ensures the existence of a physical measure}. We then give more details on recent results on the dynamics of singular-hyperbolic (Lorenz-like) attractors.Comment: 40 pages; 10 figures; Keywords: sensitive dependence on initial conditions, physical measure, singular-hyperbolicity, expansiveness, robust attractor, robust chaotic flow, positive Lyapunov exponent, large deviations, hitting and recurrence times. Minor typos corrected and precise acknowledgments of financial support added. To appear in Int J of Bif and Chaos in App Sciences and Engineerin

The role of nelarabine in the treatment of T-cell acute lymphoblastic leukemia: literature review and own experience

Aim. The analysis of experience of nelarabine use in refractory/relapsed T-cell acute lymphoblastic leukemia (T-ALL) depending on the immunophenotype and the line of therapy. Materials and methods. All the patients with relapsed or refractory T-ALL aged from 0 to 18 years who received treatment with nelarabine as a part of the therapeutic element R6 were included in the study. For all patients a detailed immunological analysis of leukemia cells with discrimination of immunological variants TI, TII, TIII or TIV was performed. Patients administered with nelarabine as a first therapeutic element were referred to the first-line therapy group, other patients were referred to the second-line therapy group. Nelarabine was administered as intravenous infusion at a dose of 650 mg/m2, on days 1-5. Allogeneic hematopoietic stem cells transplantation (allo-HSCT) was considered for all patients. Results. From 2009 to 2017, 54 patients with refractory/relapsed T-ALL were treated with nelarabine. Five-year event-free survival (EFS) and overall survival (OS) was 28% for all patients, cumulative risk of relapse (CIR) was 27%. EFS was significantly higher in nelarabine first-line therapy group in comparison with second-line therapy group (34±8% vs 8±8%, p=0,05). In patients after allo-HSCT EFS, OS and CIR were 51±10%, 50±10% and 39,1±9,5% accordingly. The best results were achieved in patients with TI immunophenotype. No toxicity-related mortality as well as severe neurologic complications or discontinuation of therapy associated with use of nelarabine were reported. Conclusion. The use of nelarabine is an effective strategy for the treatment of relapsed and refractory T-ALL. The best treatment outcomes were obtained in patients with TI immunophenotype and in the first-line therapy group. Optimal dosage regimens can be established during controlled clinical trials

Determination of the basin of attraction of a periodic orbit in two dimensions using meshless collocation

A contraction metric for an autonomous ordinary differential equation is a Riemannian metric such that the distance between adjacent solutions contracts over time. A contraction metric can be used to determine the basin of attraction of a periodic orbit without requiring information about its position or stability. Moreover, it is robust to small perturbations of the system. In two-dimensional systems, a contraction metric can be characterised by a scalar-valued function. In [9], the function was constructed as solution of a first-order linear Partial Differential Equation (PDE), and numerically constructed using meshless collocation. However, information about the periodic orbit was required, which needed to be approximated. In this paper, we overcome this requirement by studying a second-order PDE, which does not require any information about the periodic orbit. We show that the second-order PDE has a solution, which defines a contraction metric. We use meshless collocation to approximate the solution and prove error estimates. In particular, we show that the approximation itself is a contraction metric, if the collocation points are dense enough. The method is applied to two examples

Опыт одномоментных операций при билатеральной нефробластоме у детей

The paper describes the personal experience with one-stage operations for bilateral nephroblastoma (BN) in children. In 2000 to 2012, the Research Institute of Pediatric Oncology and Hematology, N.N. Blokhin Russian Cancer Research Institute, performed one-stage surgical interventions in 21 (26.2 %) children with BN. Their age ranged from 10 months to 5 years. The one-stage surgery as bilateral nephrectomy was made in 9 children. Nephrectomy with one-stage resection of the contralateral kidney was carried out in 4 children; 4 patients underwent one-stage surgery as resection of one kidney and biopsy of the other and 4 patients had nephrectomy and biopsy of the second kidney. BN is a rare disease as suggested by the data available in the world literature; each new report on patients with BN is of great scientific and practical interest. The rate of BN is 4 to 10 % of all kidney cancers in children. Synchronous and metachronous kidney injuries are encountered in 5–7 and 2–3 % of cases, respectively. Bilateral renal involvement is more commonly diagnosed in younger children. The major peak incidence of BN occurs from ages 3 to 5 years. The disease is rarely diagnosed in children above 10 years. Boys and girls are equally frequently ill. В статье приведен персональный опыт одномоментных операций при билатеральной нефробластоме (БН) у детей. В период с 2000 по 2012 г. в НИИ детской онкологии и гематологии ФГБНУ «РОНЦ им. Н.Н. Блохина» выполнены одномоментные хирургические вмешательства 21 (26,2 %) ребенку, больному БН. Возраст детей колебался от 10 мес до 5 лет. Одномоментное оперативное вмешательство в объеме резекции почки с обеих сторон проведено 9 детям. Нефрэктомия с одномоментной резекцией противоположной почки выполнена 4 детям, 4 больным проведена одномоментная операция в объеме резекции одной почки и биопсии другой почки и 4 пациентам выполнена нефрэктомия и биопсия 2-й почки. БН – редкое заболевание, о чем свидетельствуют данные мировой литературы, каждое новое сообщение о больных БН представляет важный научный и практический интерес. БН составляет от 4 до 10 % всех злокачественных опухолей почек у детей. Синхронное поражение почек наблюдается в 5–7 % случаев, метахронное – в 2–3 %. Билатеральное поражение почек диагностируется чаще у детей более раннего возраста. Основной пик заболеваемости БН приходится на возрастной период от 3 до 5 лет. Редко заболевание диагностируется у детей старше 10 лет. Мальчики и девочки болеют одинаково часто.

Review on computational methods for Lyapunov functions

Lyapunov functions are an essential tool in the stability analysis of dynamical systems, both in theory and applications. They provide sufficient conditions for the stability of equilibria or more general invariant sets, as well as for their basin of attraction. The necessity, i.e. the existence of Lyapunov functions, has been studied in converse theorems, however, they do not provide a general method to compute them. Because of their importance in stability analysis, numerous computational construction methods have been developed within the Engineering, Informatics, and Mathematics community. They cover different types of systems such as ordinary differential equations, switched systems, non-smooth systems, discrete-time systems etc., and employ di_erent methods such as series expansion, linear programming, linear matrix inequalities, collocation methods, algebraic methods, set-theoretic methods, and many others. This review brings these different methods together. First, the different types of systems, where Lyapunov functions are used, are briefly discussed. In the main part, the computational methods are presented, ordered by the type of method used to construct a Lyapunov function