ВОДОТРУБНО-ДЫМОГАРНЫЙ КОТЕЛ: ЧИСЛОВОЕ КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ И ЭКСПЕРИМЕНТ

The improvement of natural gas use technologies in water-heating boilers is considered. The concept of a new watertube smoke tube boiler, created on the basis of the screen radial tube bundle placement in the space of a cylindrical heat pipe-furnace. The results of numerical computer simulation of the furnace process in the 630 kW watertube smoke tube boiler are compared with the corresponding data obtained during the experiment. The analysis of the results of numerical computer simulation reveals the efficiency of the installed tube radial bundle: the total heat perception in the furnace increased by 56 %, while the growth of the part of the heat transferred by convective heat exchange occurred by 22 %; the temperature level in the furnace volume has decreased, while the concentration of nitrogen oxides has decreased by 45–51 %. It is experimentally established that the presence of the cooled screen tube radial bundle in the furnace of the watertube smoke tube boiler makes it possible: to increase heat release rate in the furnace volume by 10 %; to reduce the concentration of nitrogen oxides and carbon monoxide in flue gases by 24–40 % and 25–67 % respectively (resulting in a compliance of the level of pollutant emission to the requirements of the Ukrainian national regulations, viz. GOST 30735–2001); reduce the excess air in the furnace by 3 % and increase the efficiency of the boiler by 0.5 %. The pre-production prototype of the water-heating smoke tube boiler (KVVD-0.63 Gn) has passed the certification tests, state registration; the boiler has been adopted in permanent operation. The boiler is not complicated in manufacturing, and producible in the conditions of municipal heating network companies. The reliability of the boiler's design has been confirmed by the experience of many years of functioning.Рассмотрено усовершенствование технологий использования природного газа в водогрейных котлах. Предложена концепция нового водотрубно-дымогарного котла, созданного на основе размещения в пространстве цилиндрической жаровой трубы-топки экранного радиального трубного пучка. Результаты числового компьютерного моделирования топочного процесса водотрубно-дымогарного котла тепловой мощностью 630 кВт сравнивались с соответствующими данными, полученными в ходе эксперимента. Анализ результатов числового компьютерного моделирования свидетельствует об эффективности установленного трубного радиального пучка: на 56 % увеличилось общее тепловосприятие топки, при этом на 22 % выросла часть теплоты, переданной конвективным теплообменом; снизился уровень температуры в топочном пространстве, при этом на 45–51 % сократилась концентрация оксидов азота. Экспериментально установлено, что наличие охлаждаемого экранного трубного радиального пучка в топке водотрубно-дымогарного котла позволяет: увеличить тепловое напряжение топочного объема на 10 %; сократить концентрацию оксидов азота и монооксида углерода в дымовых газах на 24–40 % и на 25–67 % соответственно, при этом уровень выбросов вредных веществ удовлетворяет требованиям норм Украины (ГОСТ 30735–2001); снизить избыток воздуха в топке на 3 % и повысить КПД котла на 0,5 %. Опытный образец водогрейного водотрубно-дымогарного котла (КВВД-0,63 Гн) прошел сертификационные испытания, государственную регистрацию, принят в постоянную эксплуатацию. Котел прост в изготовлении и может производиться в условиях предприятий коммунальных тепловых сетей. Надежность конструкции котла подтверждается опытом многолетней эксплуатации

Traces of explosive volcanic eruptions in the Upper Ordovician of the Siberian Platform

© 2014, Estonian Academy Publishers. All rights reserved. Ordovician K-bentonite beds have a long history of investigation all around the world. They have been reported from Gondwana, the Argentine Precordillera, the Yangtze Platform, Laurentia, Baltica, and numerous terrains between Gondwana and Baltica, which now constitute a part of Europe. In recent years several K-bentonite beds have also been discovered in the Upper Ordovician of the Siberian Platform. This discovery is significant not only for their value in local and regional chronostratigraphic correlation but also for global geochronology, paleogeography, paleotectonic and paleoclimatic reconstructions. All in all, eight individual K-bentonite beds have been identified in the Baksian, Dolborian and Burian regional stages, which correspond roughly to the Upper Sandbian–Katian Global Stages. Zircon crystals from the uppermost K-bentonite bed within the Baksian regional stage provide a 206Pb/238U age of 450.58 ± 0.27 Ma. We will present preliminary results of the study of the three lowermost beds from the Baksian Regional Stage and suggest that the Taconic–Enisej (also spelled Yenisei or Yenisey) volcanic arc was continuous along the western margin of Siberia

Salt-tolerant genes from halophytes are potential key players of salt tolerance in glycophytes

Crop productivity strongly depends on several biotic and abiotic factors. Salinity is one of the most important abiotic factors, besides drought, extreme temperatures, light and metal stress. The enhanced burden of secondary salinization induced through anthropogenic activities increases pressure on glycophytic crop plants. The recent isolation and characterization of salt tolerance genes encoding signaling components from halophytes, which naturally grow in high salinity, has provided tools for the development of transgenic crop plants with improved salt tolerance and economically beneficial traits. In addition understanding of the differences between glycophytes and halophytes with respect to levels of salinity tolerance is also one of the prerequisite to achieve this goal. Based on the recent developments in mechanisms of salt tolerance in halophytes, we will explore the potential of introducing salt tolerance by choosing the available genes from both dicotyledonous and monocotyledonous halophytes, including the salt overly sensitive system (SOS)-related cation/proton antiporters of plasma (NHX/SOS1) and vacuolar membranes (NHX), energy-related pumps, such as plasma membrane and vacuolar H+ adenosine triphosphatase (PM& V-H+ATPase), vacuolar H+ pyrophosphatases (V-H+PPase) and potassium transporter genes. Various halophyte genes responsible for other processes, such as crosstalk signaling, osmotic solutes production and reactive oxygen species (ROS) suppression, which also enhance salt tolerance will be described. In addition, the transgenic overexpression of halophytic genes in crops (rice, peanut, finger millet, soybean, tomato, alfalfa, jatropha, etc.) will be discussed as a successful mechanism for the induction of salt tolerance. Moreover, the advances in genetic engineering technology for the production of genetically modified crops to achieve the improved salinity tolerance under field conditions will also be discussed

ОЦЕНКА ЭФФЕКТИВНОСТИ ВОЗДЕЙСТВИЯ БОР-НЕЙТРОНОЗАХВАТНОЙ ТЕРАПИИ НА РАЗЛИЧНЫЕ ОПУХОЛЕВЫЕ И НОРМАЛЬНУЮ КЛЕТОЧНЫЕ КУЛЬТУРЫ

Introduction. Boron neutron capture therapy (bnct) is a promising method for treating tumors, in particular, infiltrative malignant tumors, due to the selective destruction of tumor cells without damaging the surrounding normal tissues. This type of therapy is based on nuclear reaction of neutron capture by stable 10b isotope. For the successful implementation of bnct, boron delivery drugs that must be selectively accumulated in malignant cells in a sufficient amount, and a neutron source with the energy required for the neutron capture reaction are needed. At the budker institute of nuclear physics, the accelerator-based neutron source was designed with flux parameters allowing studies on bnct to be conducted.Objective: to assess the effect of bnct on tumor and normal cell lines using borphenylalanine (bpa), borcaptate (bsh) and liposomal borcaptat as boron delivery drugs.Materials and methods. Human cell cultures: glioblastoma (u87), colorectal human adenocarcinoma (sw-620), human melanoma (sk-mel28) and primary embryonic cell lines were irradiated with a neutron flux at the presence of bpa, bsh and liposomal bsh with a concentration of 10b 40 μg/ml. The short-term cytotoxic effect of irradiation was evaluated using trypan blue. Cell survival 96 hours after irradiation was determined using mtt test, and survival fraction was evaluated using the clonogenic test.Results. Early cytotoxic effects of irradiation were not observed for all 4 cell lines. According to mtt and clonogenic tests, the most pronounced effect of bnct was noticed for sw-620 and u87 lines, regardless of boron delivery drug used. For sk-mel28 line, the best effect was achieved after irradiation with liposomal borocaptate. For the primary transplanted embryonic line, high toxicity was revealed when bnct was performed with borphenylalanine and borcaptate.Conclusion. The data obtained indicate that the accelerator-based bnct using boron delivery drugs, such as borphenylalanine, borcaptate and liposomal borcaptat, has a positive effect on tumor lines of glioblastoma, colorectal adenocarcinoma and melanoma.Введение. В институте ядерной физики им. Г.и. Будкера СО РАн был сконструирован источник нейтронов ускорительного типа с параметрами потока, позволяющими проводить эксперименты по бор-нейтронозахватной терапии (БнЗТ). В основе БнЗТ лежит микроядерная реакция внутри клетки, возникающая в результате поглощения нейтрона стабильным изотопом 10B.Целью исследования явилось определение влияния БнЗТ на опухолевые клеточные линии и на первично-перевиваемую эмбриональную линию с использованием борфенилаланина (BPa), боркаптата (BsH) и липосомального боркаптата в качестве препаратов бора.Материал и методы. клеточные культуры человека: глиобластома (u87), колоректальная аденокарцинома  человека (sW-620), меланома человека (sK-Mel28) и первичная эмбриональная клеточная линия были  облучены потоком нейтронов в присутствии препаратов бора с концентрацией 10В 40 мкг/мл.Результаты. Ранних цитотоксических эффектов облучения (через 2–4 ч) в отношении всех 4 линий клеток при окрашивании трипановым синим обнаружено не было. По данным МТТ и клоногенного тестов наиболее выраженное снижение выживаемости после БнЗТ было отмечено для линий sW-620 и u87 вне зависимости от используемого препарата доставки бора. Для линии sK-Mel28 наилучший цитотоксический эффект был достигнут при облучении с липосомальным боркаптатом. Для первично-перевиваемой эмбриональной линии была выявлена высокая токсичность при проведении БнЗТ с препаратами борфенилаланина и боркаптата.Выводы. Анализ полученных данных указывает на эффективность воздействия БнЗТ, проводимой на источнике нейтронов ускорительного типа иЯФ СО РАн, на опухолевые линии глиобластомы, колоректальной  аденокарциномы и меланомы при использовании препаратов борфенилаланин, боркаптат и липосомальный боркапта

ЦИТОПАТИЧЕСКИЕ ЭФФЕКТЫ БОР-НЕЙТРОНОЗАХВАТНОЙ ТЕРАПИИ НА УСКОРИТЕЛЬНОМ ИСТОЧНИКЕ ЭПИТЕПЛОВЫХ НЕЙТРОНОВ ДЛЯ КУЛЬТУРЫ КЛЕТОК ГЛИОБЛАСТОМЫ ЧЕЛОВЕКА

Boron neutron capture therapy (BNCT) is a targeted therapy based on a selective damage to cancer cells due to the interaction between boron-10 isotope and neutron. Reactor-based BNCT has been found to be effective in the treatment of high-grade gliomas. It is believed that compact accelerator-based neutron sources will ensure widespread adoption of the technique in clinical practice. New accelerator-based neutron sources are being actively developed all over the world. At the Institute of Nuclear Physics (Russia), the accelerator-based neutron source was developed for pre-clinical studies of BNCT.Purpose: to determine the cytopathic effects of accelerator-based BNCT on the human U87-glioblastoma cell line and to select a concentration of boron drugs that do not have a toxic effect on the cells before irradiation in vitro.Material and Methods. To assess the cytopathic effects (MTT test and colony-forming assay) of various concentrations of boron-containing drugs, U87 cells were incubated with boronophenylalanine (BPA) and sodium borocaptate (BSH) for 1, 2 and 10 days. The effect of BNCT on the U87 cell line was determined using colony-forming assay.Results. The MTT test showed a decrease in cell survival at a boron-10 isotope concentration of 160 μg/ml after 48 hours and 640 μg/ml after 24 hours of incubation for BPA. The cytopathic effects for sodium BSH appeared at a boron concentration of 80 µg / ml after 48 hours of incubation, and survival fraction of cells was reduced to 89 % compared to the control. According to the colonyforming assay, the cytotoxic effects of BSH and BPA at a boron concentration of 40 µg/ml in the medium were 79.6 and 84 %, respectively. The proportions of surviving cells were 18 ± 2 % and 13 ± 2 % after epithermal neutron irradiation in the presence of boronophenylalanine and in the presence of sodium borocaptate, respectively. Cell death without boron drugs occurred due to the neutron elastic scattering, nuclear reactions of thermal neutron capture by hydrogen and nitrogen, and accompanying gamma radiation.Conclusion. The study clearly showed a decrease in the proportion of surviving U87 cells after accelerator-based BNCT in the presence of 10B-enriched BSH and BPA. Бор-нейтронозахватная терапия (БНЗТ) – экспериментальный метод лучевой терапии, основанный на селективном повреждении клеток злокачественных опухолей за счет реакции между изотопом бор-10 и нейтроном. Клинические исследования на ядерных реакторах доказали эффективность данного вида терапии для пациентов с глиомами высокой степени злокачественности. Считается, что широкое внедрение методики в клиническую практику обеспечит компактные источники нейтронов на основе ускорителей заряженных частиц. Во всем мире ведется активная разработка новых ускорительных источников нейтронов, в том числе и в России: в Институте ядерной физики СО РАН был предложен и создан такой источник, на котором в настоящее время проводят доклинические испытания БНЗТ.Цель исследования – определить цитопатические эффекты БНЗТ на ускорителе эпитепловых нейронов для культуры клетки глиобластомы человека U87 и выбрать концентрацию препаратов бора, не оказывающую токсического влияния на клетки до облучения in vitro.Материал и методы. Клетки линии U87 инкубировали с борфенилаланином (BPA) и боркаптатом (BSH) в течение 1, 2 и 10 сут в различных концентрациях. Оценку цитопатических эффектов препаратов бора проводили с помощью МТТ-теста и клоногенного теста. Эффективность БНЗТ на клеточной линии U87 определяли на основании клоногенного теста.Результаты. МТТ-тест показал снижение выживаемости клеток при концентрации изотопа бора-10 в среде 160 мкг/мл через 48 ч и 640 мкг/мл через 24 ч инкубации для BPA. Цитопатические эффекты BSH проявляются при концентрации бора 80 мкг/мл после 48-часовой инкубации, а доля выживших клеток снижается до 89 % по сравнению с контролем. Согласно клоногенному тесту, цитотоксические эффекты препаратов BSH и BPA при концентрации бора в среде 40 мкг/мл составили 79,6 и 84 % соответственно. При облучении клеток эпитепловыми нейтронами в присутствии BPA доля выживших клеток составила 18 ± 2 %, в присутствии BSH – 13 ± 2 %. Гибель клеток без препаратов бора обусловлена упругим рассеянием нейтронов, ядерными реакциями поглощения тепловых нейтронов водородом и азотом и сопутствующим γ-излучением.Заключение. Проведенное исследование наглядно показало уменьшение доли выживших клеток линии U87 после БНЗТ на ускорительном источнике эпитепловых нейтронов в ИЯФ СО РАН в присутствии препаратов BSH и BPA, обогащенных изотопом 10В

WATERTUBE SMOKE TUBE BOILER: NUMERICAL COMPUTER SIMULATION AND EXPERIMENT

The improvement of natural gas use technologies in water-heating boilers is considered. The concept of a new watertube smoke tube boiler, created on the basis of the screen radial tube bundle placement in the space of a cylindrical heat pipe-furnace. The results of numerical computer simulation of the furnace process in the 630 kW watertube smoke tube boiler are compared with the corresponding data obtained during the experiment. The analysis of the results of numerical computer simulation reveals the efficiency of the installed tube radial bundle: the total heat perception in the furnace increased by 56 %, while the growth of the part of the heat transferred by convective heat exchange occurred by 22 %; the temperature level in the furnace volume has decreased, while the concentration of nitrogen oxides has decreased by 45–51 %. It is experimentally established that the presence of the cooled screen tube radial bundle in the furnace of the watertube smoke tube boiler makes it possible: to increase heat release rate in the furnace volume by 10 %; to reduce the concentration of nitrogen oxides and carbon monoxide in flue gases by 24–40 % and 25–67 % respectively (resulting in a compliance of the level of pollutant emission to the requirements of the Ukrainian national regulations, viz. GOST 30735–2001); reduce the excess air in the furnace by 3 % and increase the efficiency of the boiler by 0.5 %. The pre-production prototype of the water-heating smoke tube boiler (KVVD-0.63 Gn) has passed the certification tests, state registration; the boiler has been adopted in permanent operation. The boiler is not complicated in manufacturing, and producible in the conditions of municipal heating network companies. The reliability of the boiler's design has been confirmed by the experience of many years of functioning

Electrostatic Twisting of Core-Shell Nanofibers for Strain Sensing Applications

Stretchable strain sensors are increasingly needed in emerging fields of wearable electronics and smart textiles for applications ranging from human motion detection to health monitoring. Nanofibers made from conductive materials or composites of polymers and conductive nanoparticles exhibit strong sensitivities but are difficult to utilize due to their small dimensions. Herein, we report on a technique for producing core-shell nanofibers and in-situ twisting of them to each other using a rotating electric field. The process produces sensitive threads that can be handled easily and used, for instance, in smart textile applications. The core-shell nanofibers utilized poly(vinylidene fluoride) as the structural polymer and multiwalled carbon nanotubes were used to make the core electrically conductive. The structure of nanofibers was studied through a set of analytical methods. The fibers exhibit strong piezoresistive responses and can be utilized in various strain sensing applications. Mechanical properties of fabricated submicron fiber yarns are compared with non-twisted fibers and improvement of their stretchability has been demonstrated. Furthermore, the sensitivity of fiber threads to different directions of stretching depended on the way of their knitting into fabric has been compared

Traces of explosive volcanic eruptions in the Upper Ordovician of the Siberian Platform

© 2014, Estonian Academy Publishers. All rights reserved. Ordovician K-bentonite beds have a long history of investigation all around the world. They have been reported from Gondwana, the Argentine Precordillera, the Yangtze Platform, Laurentia, Baltica, and numerous terrains between Gondwana and Baltica, which now constitute a part of Europe. In recent years several K-bentonite beds have also been discovered in the Upper Ordovician of the Siberian Platform. This discovery is significant not only for their value in local and regional chronostratigraphic correlation but also for global geochronology, paleogeography, paleotectonic and paleoclimatic reconstructions. All in all, eight individual K-bentonite beds have been identified in the Baksian, Dolborian and Burian regional stages, which correspond roughly to the Upper Sandbian–Katian Global Stages. Zircon crystals from the uppermost K-bentonite bed within the Baksian regional stage provide a 206Pb/238U age of 450.58 ± 0.27 Ma. We will present preliminary results of the study of the three lowermost beds from the Baksian Regional Stage and suggest that the Taconic–Enisej (also spelled Yenisei or Yenisey) volcanic arc was continuous along the western margin of Siberia

How to Plan and Evaluate the Work of Computer Centers

Our country's computer potential is increasing at a rapid rate. Our aggregate computer capacities increased more than fourfold under the Tenth Five-Year Plan compared with the preceding five-year plan. There was a concurrent increase in the number of computer centers as the major organizational form in which computers are used. Computer centers (which now number almost 4,000) have become mass-type organizations. The majority of them serve the more than 5,000 automated control systems of different classes and designations. Under the last five-year plan, a number of branches in the national economy allocated up to 3 % of the capital investments in the development of the branch for the formation of computer centers and automated control systems. Quantitative growth is accompanied by the concentration and centralization of the computerized production of information, by its integration, by the creation of group and collectively used computer centers based on large multicomputer complexes.