Моделирование микроструктуры и расчет фактора извилистости для катодных материалов LSM-YSZ

In this work changes in physico-chemical properties (oxygen interphase exchange rate and specific resistance) and microstructure parameters (TPB length and tortuosity factor) with time have been analyzed to find the quantitative relationships on the example of composite cathode material LSM-YSZ. 3D microstructure of LSM-YSZ materials has been reconstructed and tortuosity factor has been calculated on the basis of SEM image analysis using the original software.В работе на примере композиционного материала LSM-YSZ сравнивается изменение физико-химических свойств (скорости межфазного обмена кислорода и удельного сопротивления) и параметров микроструктуры (протяженности ТФГ и фактора извилистости) от времени с целью нахождения количественных взаимосвязей. Для электродных материалов LSM-YSZ проведена 3D-реконструкция микроструктуры и рассчитан фактор извилистости на основе результата анализа изображений РЭМ с использованием оригинального программного обеспечения.This work was done under financial support from RFBR grant № 12-03-31847 / 12 and the Federal Program № 2012-1.3.1-12-000-2006-004, number 8713.Работа выполнена при финансовой поддержке грантов РФФИ № 12-03-31847/12 и ФЦП № 2012-1.3.1-12-000-2006-004, соглашение № 8713

ИССЛЕДОВАНИЕ ЧАСТОТНО-ВЛАЖНОСТНЫХ ДИЭЛЕКТРИЧЕСКИХ ХАРАКТЕРИСТИК КОРМОВЫХ ТРАВ

In the technologies of green fodder production from freshly harvested grass the moisture content control plays the important role in maintenance of high quality and decrease in losses of prepared fodder. The main field technique of moisture control is the dielectric measuring providing rapidity, comprehensible accuracy, simplicity of use and relatively low cost. The experimental measuring device for investigation of wet grasses dielectric properties based on the capacitive sensor and Agilent 4294А Precision Impedance Analyzer, over the electromagnetic field frequency range of 1-30 MHz, used for measurement of grass moisture content, was presented. Parameters of the flat ring capacitive sensor are studied, and a choice of it was proved. The necessary compacting pressure upon grass samples at calculation of their dielectric characteristics was determined. The problem of conversion the measured by the precision impedance analyzer parameters of a cable with the connected capacitive sensor into parameters of tested material has been solved. The preparation procedure of wet grasses to measuring was developed. The geometrical constant of the sensor was determined in the range of the used frequencies. It was determined the penetration depth of an electromagnetic field of the sensor into the tested material according to which the minimum thickness of the studied material layer under the sensor is limited. Dependences of grasses dielectric permittivity and electrical conductivity in the chosen frequency range were experimentally investigated at various values of moisture content and compacting pressure. By results of researches of dielectric properties of grass plants in 2013-2014 a choice of working frequency of measurements in the range of 10-15 MHz and compacting pressure of the studied grasses of 0.31-0.5 N per square meter created by the device was proved.В технологиях производства кормов из зеленой массы скошенных трав контроль влажности играет важную роль в обеспечении высокого качества и снижении потерь заготавливаемых кормов. Основной метод полевого контроля влажности - диэлькометрия, обеспечивающая быстроту, приемлемую точность, простоту использования и невысокую стоимость средств измерений. Представили экспериментальную лабораторную установку для определения влажности трав на основе емкостного датчика и прецизионного измерителя импеданса Agilent 4294A в диапазоне частот электромагнитного поля 1-30 МГц. Обосновали выбор и исследовали параметры плоского кольцевого емкостного датчика. Определили необходимое уплотняющее давление на образцы трав при расчете их диэлектрических характеристик. Решили задачу пересчета измеряемых прецизионным измерителем импеданса параметров кабеля с подключенным емкостным датчиком в параметры тестируемого материала. Разработали методику подготовки влажных трав к измерениям. Установили геометрическую постоянную датчика в диапазоне используемых частот. Определили глубину проникновения электромагнитного поля датчика в тестируемый материал, задающую минимальную толщину исследуемого слоя материала под датчиком. Экспериментально исследовали зависимость диэлектрической проницаемости и электропроводности трав в выбранном диапазоне частот при различных влажностях и уплотняющих давлениях. По результатам исследований диэлектрических свойств трав в 2013-2014 гг. обосновали выбор рабочей частоты измерений в диапазоне 10-15 МГц и создаваемого прибором давления уплотнения 0,31-0,5 Н на 1 кв. см исследуемых трав

Internal flows and energy circulation in light beams

We review optical phenomena associated with the internal energy redistribution which accompany propagation and transformations of monochromatic light fields in homogeneous media. The total energy flow (linear-momentum density, Poynting vector) can be divided into spin part associated with the polarization and orbital part associated with the spatial inhomogeneity. We give general description of the internal flows in the coordinate and momentum (angular spectrum) representations for both nonparaxial and paraxial fields. This enables one to determine local densities and integral values of the spin and orbital angular momenta of the field. We analyse patterns of the internal flows in standard beam models (Gaussian, Laguerre-Gaussian, flat-top beam, etc.), which provide an insightful picture of the energy transport. The emphasize is made to the singular points of the flow fields. We describe the spin-orbit and orbit-orbit interactions in the processes of beam focusing and symmetry breakdown. Finally, we consider how the energy flows manifest themselves in the mechanical action on probing particles and in the transformations of a propagating beam subjected to a transverse perturbation.Comment: 50 pages, 21 figures, 173 references. This is the final version of the manuscript (v1) modified in accord to the referee's remarks and with allowance for the recent development. The main changes are: additional discussion of the energy flows in Bessel beams (section 4.1), a lot of new references are added and the Conclusion is shortened and made more accurat

Electromagnetically assisted densification of copper-sheathed in situ MgB2/Cu wires

peer-reviewedThis paper summarizes recent methods of improving critical current density of in situ Cu-sheathed MgB2 wires. These methods include using optimum heat treatment schedule, adding copper powder to the wire core and electromagnetic densification of wire core. The large part of work reported here focuses on the latter method applied to the relatively low-density MgB2/Cu wire core. The packing density of unreacted, monofilament wire core was increased by 8 % with oscillating magnetic pressure, reaching a peak value above 700 MPa as calculated by finite element modelling of the forming process. The higher density of the MgB2 core combined with copper powder addition resulted in a critical current density increase of more than fivefold in comparison to purely stoichiometric and cold-drawn-only wire.PUBLISHEDpeer-reviewe

ИСПОЛЬЗОВАНИЕ ПАКЛИТАКСЕЛА В ХИМИОЛУЧЕВОЙ ТЕРАПИИ БОЛЬНЫХ ПЛОСКОКЛЕТОЧНЫМ РАКОМ АНАЛЬНОГО КАНАЛА: ПИЛОТНОЕ ИССЛЕДОВАНИЕ

Objectives: to assess the feasibility of a combination of the intensity-modulated radiation therapy (IMRT) with a triplet chemotherapy with paclitaxel, capecitabine, and mitomycin C in the treatment of patients with anal cancer, and to evaluate the toxicity of the proposed treatment regimen.Materials and methods. All patients included in the study had stage I–IIIB anal cancer. All patients underwent IMRT radiotherapy 52–58 Gy (the dosage is calculated according T symbol) by 1.8 to 2.2 Gy fractions daily. The proposed chemotherapy scheme includes mitomycin C 10 mg/m2 on day 1, paclitaxel 45 mg/m2 on days 3, 10, 17, 24, 31, capecitabine 625 mg/m2 during radiotherapy. A complete response to treatment after 26 weeks, and the compliance to the study protocol were the primary end points of the study.Results. The study included 38 patients. Among patients stage I anal cancer occurred in 1 (2.6 %) case, II – in 5 (13.2 %), IIIA – 15 (39.5 %) and IIIB – in 17 (44.7 %). A significant deviation from the protocol reported in 6 (15.8 %) patients, in 11 (28.9 %) patients a slight alteration from the treatment was documented, and 21 (55.3 %) patients completed the treatment of chemoradiotherapy with full compliance to the study protocol. The high profile of toxicity (grade III–IV) was recorded in 23 (60.5 %) patients. An incomplete clinical response at 26 weeks after treatment was reported in 5 (13.2 %) patients, one whom continued watchful waiting and achieved complete response at 9 months posttreatment. Median followup was 27 months. 1 patient developed a local recurrence 1 year posttreatment.Conclusions. The proposed triplet chemotherapy regimen using IMRT is feasible and has acceptable toxicity. For further assess the continuous research is needed. Целью исследования явилась оценка эффективности лучевой терапии с модулированной интенсивностью (intensity-modulated radiation therapy, IMRT) с трехкомпонентной химиотерапией паклитакселом, капецитабином и митомицином С в лечении пациентов, больных раком анального канала, а также изучение профиля токсичности предложенной схемы лечения.Материалы и методы. Все пациенты, включенные в исследование, имели I–IIIB стадии опухолевого процесса. Больным была проведена лучевая терапия по технологии IMRT последовательными фракциями от 1,8 до 2,2 Гр ежедневно до суммарной очаговой дозы 52–58 Гр (в зависимости от исходной стадии Т). Предложенная схема химиотерапии включала прием митомицина С 10 мг/м2 внутривенно (в/в) в 1-й день, паклитаксела 45 мг/м2 в/в в 3, 10, 17, 24 и 31-й дни, капецитабина 625 мг/м2 2 раза в сутки перорально в дни лучевой терапии. Полный ответ на лечение через 26 нед и соблюдение протокола исследования являлись основными оцениваемыми параметрами.Результаты. В исследование были включены 38 пациентов. Опухолевый процесс I стадии был выявлен у 1 (2,6 %), II – у 5 (13,2 %), IIIA – у 15 (39,5 %) и IIIB – у 17 (44,7 %) больных. Значительное отступление от протокола зарегистрировано у 6 (15,8 %) пациентов, у 11 (28,9 %) отмечено незначительное отступление от схемы лечения, 21 (55,3 %) больной завершил режим химиолучевой терапии в полном соответствии с протоколом исследования. Высокий профиль токсичности (III–IV степени тяжести) зарегистрирован у 23 (60,5 %) пациентов. Неполный клинический ответ через 26 нед после окончания лечения был отмечен у 5 (13,2 %) больных, из них 1 пациентке продолжено динамическое наблюдение, полный ответ достигнут через 9 мес, остальным 4 предложено хирургическое лечение. Медиана наблюдения составила 27 мес. У 1 больной развился рецидив заболевания через 1 год после завершения химиолучевой терапии.Выводы. Предложенный режим трехкомпонентной химиотерапии по протоколу IMRT имеет допустимую токсичность и позволяет достичь высоких результатов лечения у прогностически неблагоприятной группы пациентов. Для дальнейшей оценки необходимо продолжение исследований

Моделирование микроструктуры и расчет фактора извилистости для катодных материалов LSM—YSZ

In this work changes in physico-chemical properties (oxygen interphase exchange rate and specific resistance) and microstructure parameters (TPB length and tortuosity factor) with time have been analyzed to find the quantitative relationships on the example of composite cathode material LSM-YSZ. 3D microstructure of LSM-YSZ materials has been reconstructed and tortuosity factor has been calculated on the basis of SEM image analysis using the original software.В работе на примере композиционного материала LSM—YSZ сравнивается изменение физико-химических свойств (скорости межфазного обмена кислорода и удельного сопротивления) и параметров микроструктуры (протяженности ТФГ и фактора извилистости) от времени с целью нахождения количественных взаимосвязей. Для электродных материалов LSM—YSZ проведена 3D-реконструкция микроструктуры и рассчитан фактор извилистости на основе результата анализа изображений РЭМ с использованием оригинального программного обеспечения

RESEARCH OF FREQUENCY-HUMIDITY DIELECTRIC CHARACTERISTICS OF FORAGE GRASSES

In the technologies of green fodder production from freshly harvested grass the moisture content control plays the important role in maintenance of high quality and decrease in losses of prepared fodder. The main field technique of moisture control is the dielectric measuring providing rapidity, comprehensible accuracy, simplicity of use and relatively low cost. The experimental measuring device for investigation of wet grasses dielectric properties based on the capacitive sensor and Agilent 4294А Precision Impedance Analyzer, over the electromagnetic field frequency range of 1-30 MHz, used for measurement of grass moisture content, was presented. Parameters of the flat ring capacitive sensor are studied, and a choice of it was proved. The necessary compacting pressure upon grass samples at calculation of their dielectric characteristics was determined. The problem of conversion the measured by the precision impedance analyzer parameters of a cable with the connected capacitive sensor into parameters of tested material has been solved. The preparation procedure of wet grasses to measuring was developed. The geometrical constant of the sensor was determined in the range of the used frequencies. It was determined the penetration depth of an electromagnetic field of the sensor into the tested material according to which the minimum thickness of the studied material layer under the sensor is limited. Dependences of grasses dielectric permittivity and electrical conductivity in the chosen frequency range were experimentally investigated at various values of moisture content and compacting pressure. By results of researches of dielectric properties of grass plants in 2013-2014 a choice of working frequency of measurements in the range of 10-15 MHz and compacting pressure of the studied grasses of 0.31-0.5 N per square meter created by the device was proved

On regulatory framework of forestry intensification

The paper reviews research papers, develops recommendations for forest regulatory documents. Some deficiencies in the current regulatory framework are revealed. Traditionally, the system of normative documents had a hierarchical structure. The upper level contained basic principles and the most general provisions, while regional level documents focused on local features of forest growth, and also analyzed possible differences within the region. In addition to the geographical aspect, progress in the development of forestry practices, new scientific data and gradual changes in the forest fund were also taken into account, which encouraged periodic updating of standards. The last time it happened more than 20 years ago. The current standards regulating the main stages of forest growing – reforestation, forest care and felling of mature tree stands – are considered. Specific examples illustrate problems, caused by the imperfection in forest legislation, insufficient study of natural and economic characteristics of the regions, progress in the development of logging equipment and considerable changes in the forest fund. It is pointed out that there is a need for normative measures for recording the costs of carrying out activities. It is noted that these shortcomings are a consequence of neglect of the principal issues of domestic forestry. It is shown that system for assessing stand thinning quality is imperfect and the interpretation of the results of the work is ambiguous. It is proposed to base the assessment on absolute indicators, as is accepted in international practice. The urgent need to plan biodiversity conservation activities taking into account the peculiarities of natural and territorial complexes is shown. We suggest to improve the situation, with proposals aimed at creating conditions to intensify forestry production and restore resource potential of taiga forests