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

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

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

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

Fuel feed to diesel at a start regime

Some factors defining starting properties of diesel engines are considered. Features of process of fuel feed on a starting mode are analyzed. Basic possibility of steering by processes of mixture forming and combustion is proved at a small speed of a crankshaft. Developed a design procedure of process of fuel feed in a diesel engine at a start regime. On the basis of the theory of transients in a fuel system, the reasons of deterioration of indicators of fuel feed process are explained at a start regime of diesel engine. Possibilities of a method of increase of initial pressure in a delivery highway by prostrating scrolling of a crankshaft with idle spray jets are investigated. The method of intensification of fuel feed process patented by authors used in diesel engine at a start regime. The results of numerical experiments confirming improvement of indicators of process of injection at high-speed speeding up of the pump of a high pressure are resulted: Increase maximum and an average pressure, cutting-down of duration of fuel feed process. The paper concentrates on possibility of improving fuel fed process at the starting regime by means of high speed forcing the fuel pump and the initial pressure rising by an earlier camshaft rotation with out of work injectors

The Location of Research Potential

The Twenty-fifth Congress of the Communist Party of the Soviet Union posed the task of improving techniques used in the comprehensive solution of major nationwide interbranch and territorial problems. The improvement of the territorial location of science and the better utilization of regional research potential are some of the problems that hold great importance for the further socioeconomic development of the nation. (>u>1>/u>) The development of long-range plans for socioeconomic development and comprehensive programs of technical progress on a national, union republic, and regional scale is closely associated with the territorial location of research, project-planning, and experimental facilities.

The study of non traditional dosing method of the cycle fuel feed in diesel

It is offered to dose out a cyclic portion of fuel by change ofduration of the first period of feeding that is reached by regulation of the moment of landing of the delivery valve. The mathematical model of fuel feed system with the steered delivery valve is developed. Numerical and experimental methods defined cyclic fuel delivery at change of the moment of closing of the delivery valve. Within the limits of studying of the feeder of fuel in skilled system, redistribution of a cyclic portion of fuel between the periods of a cycle and quantity of the fuel compressed in separate cavities of a delivery high-pressure pipe was defined. The important feature of the feeder - earlier landing of the delivery valve, than nozzle valve closing is found out. It absence of repeated lifting of a nozzle valve ("secondary injections") speaks all investigated high-speed and loading modes. The offered method of dosing out of fuel feed allows eliminating an essential lack of a traditional fuel system where feeding and dosing out processes are combined. The paper explains the absence of the repeated rise of the injector needle at all calculated regimes. A wave of pressure generated at setting the valve comes to the injector before the fuel feed is over. This excludes additional fuel injections even at high initial pressure in the force main in principle

Possibilities of boron neutron capture therapy in the treatment of malignant brain tumors

Boron neutron capture therapy (BNCT) that is of the highest attractiveness due to its selective action directly on malignant tumor cells is a promising approach to treating cancers. Clinical interest in BNCT focuses in neuro-oncology on therapy for gliomas, glioblastoma in particular, and BNCT may be used in brain metastatic involvement. This needs an epithermal neutron source that complies with the requirements for BNCT, as wellas a 10B-containing agent that will selectively accumulate in tumor tissue. The introduction of BNCT into clinical practice to treat patients with glial tumors will be able to enhance therapeutic efficiency